Move gate

.cargo/config.toml

@@ -8,7 +8,3 @@ benchmark = "bench -p ruff_benchmark --bench linter --bench formatter --"
 # See: https://github.com/astral-sh/ruff/issues/11503
 [target.'cfg(all(target_env="msvc", target_os = "windows"))']
 rustflags = ["-C", "target-feature=+crt-static"]
-
-[target.'wasm32-unknown-unknown']
-# See https://docs.rs/getrandom/latest/getrandom/#webassembly-support
-rustflags = ["--cfg", 'getrandom_backend="wasm_js"']

.config/nextest.toml

@@ -6,10 +6,3 @@ failure-output = "immediate-final"
 fail-fast = false
 
 status-level = "skip"
-
-# Mark tests that take longer than 1s as slow.
-# Terminate after 60s as a stop-gap measure to terminate on deadlock.
-slow-timeout =  { period = "1s", terminate-after = 60 }
-
-# Show slow jobs in the final summary
-final-status-level = "slow"

.devcontainer/devcontainer.json

@@ -20,7 +20,7 @@
 			"extensions": [
 				"ms-python.python",
 				"rust-lang.rust-analyzer",
-				"fill-labs.dependi",
+				"serayuzgur.crates",
 				"tamasfe.even-better-toml",
 				"Swellaby.vscode-rust-test-adapter",
 				"charliermarsh.ruff"

.editorconfig

@@ -17,7 +17,4 @@ indent_size = 4
 trim_trailing_whitespace = false
 
 [*.md]
-max_line_length = 100
-
-[*.toml]
-indent_size = 4
+max_line_length = 100

.gitattributes

@@ -14,7 +14,5 @@ crates/ruff_python_parser/resources/invalid/re_lex_logical_token_mac_eol.py text
 
 crates/ruff_python_parser/resources/inline linguist-generated=true
 
-ruff.schema.json -diff linguist-generated=true text=auto eol=lf
-crates/ruff_python_ast/src/generated.rs -diff linguist-generated=true text=auto eol=lf
-crates/ruff_python_formatter/src/generated.rs -diff linguist-generated=true text=auto eol=lf
+ruff.schema.json linguist-generated=true text=auto eol=lf
 *.md.snap linguist-language=Markdown

.github/CODEOWNERS

@@ -9,16 +9,13 @@
 /crates/ruff_formatter/ @MichaReiser
 /crates/ruff_python_formatter/ @MichaReiser
 /crates/ruff_python_parser/ @MichaReiser @dhruvmanila
-/crates/ruff_annotate_snippets/ @BurntSushi
 
 # flake8-pyi
 /crates/ruff_linter/src/rules/flake8_pyi/ @AlexWaygood
 
-# Script for fuzzing the parser/red-knot etc.
-/python/py-fuzzer/ @AlexWaygood
+# Script for fuzzing the parser
+/scripts/fuzz-parser/ @AlexWaygood
 
 # red-knot
-/crates/red_knot* @carljm @MichaReiser @AlexWaygood @sharkdp @dcreager
-/crates/ruff_db/ @carljm @MichaReiser @AlexWaygood @sharkdp @dcreager
-/scripts/knot_benchmark/ @carljm @MichaReiser @AlexWaygood @sharkdp @dcreager
-/crates/red_knot_python_semantic @carljm @AlexWaygood @sharkdp @dcreager
+/crates/red_knot* @carljm @MichaReiser @AlexWaygood
+/crates/ruff_db/ @carljm @MichaReiser @AlexWaygood

.github/ISSUE_TEMPLATE.md

@@ -0,0 +1,12 @@
+<!--
+Thank you for taking the time to report an issue! We're glad to have you involved with Ruff.
+
+If you're filing a bug report, please consider including the following information:
+
+* List of keywords you searched for before creating this issue. Write them down here so that others can find this issue more easily and help provide feedback.
+  e.g. "RUF001", "unused variable", "Jupyter notebook"
+* A minimal code snippet that reproduces the bug.
+* The command you invoked (e.g., `ruff /path/to/file.py --fix`), ideally including the `--isolated` flag.
+* The current Ruff settings (any relevant sections from your `pyproject.toml`).
+* The current Ruff version (`ruff --version`).
+-->

.github/ISSUE_TEMPLATE/1_bug_report.yaml

@@ -1,31 +0,0 @@
-name: Bug report
-description: Report an error or unexpected behavior
-body:
-  - type: markdown
-    attributes:
-      value: |
-        Thank you for taking the time to report an issue! We're glad to have you involved with Ruff.
-
-        **Before reporting, please make sure to search through [existing issues](https://github.com/astral-sh/ruff/issues?q=is:issue+is:open+label:bug) (including [closed](https://github.com/astral-sh/ruff/issues?q=is:issue%20state:closed%20label:bug)).**
-
-  - type: textarea
-    attributes:
-      label: Summary
-      description: |
-        A clear and concise description of the bug, including a minimal reproducible example.
-
-        Be sure to include the command you invoked (e.g., `ruff check /path/to/file.py --fix`), ideally including the `--isolated` flag and
-        the current Ruff settings (e.g., relevant sections from your `pyproject.toml`).
-
-        If possible, try to include the [playground](https://play.ruff.rs) link that reproduces this issue.
-
-    validations:
-      required: true
-
-  - type: input
-    attributes:
-      label: Version
-      description: What version of ruff are you using? (see `ruff version`)
-      placeholder: e.g., ruff 0.9.3 (90589372d 2025-01-23)
-    validations:
-      required: false

.github/ISSUE_TEMPLATE/2_rule_request.yaml

@@ -1,10 +0,0 @@
-name: Rule request
-description: Anything related to lint rules (proposing new rules, changes to existing rules, auto-fixes, etc.)
-body:
-  - type: textarea
-    attributes:
-      label: Summary
-      description: |
-        A clear and concise description of the relevant request. If applicable, please describe the current behavior as well.
-    validations:
-      required: true

.github/ISSUE_TEMPLATE/3_question.yaml

@@ -1,18 +0,0 @@
-name: Question
-description: Ask a question about Ruff
-labels: ["question"]
-body:
-  - type: textarea
-    attributes:
-      label: Question
-      description: Describe your question in detail.
-    validations:
-      required: true
-
-  - type: input
-    attributes:
-      label: Version
-      description: What version of ruff are you using? (see `ruff version`)
-      placeholder: e.g., ruff 0.9.3 (90589372d 2025-01-23)
-    validations:
-      required: false

.github/ISSUE_TEMPLATE/config.yml

@@ -1,8 +0,0 @@
-blank_issues_enabled: true
-contact_links:
-  - name: Documentation
-    url: https://docs.astral.sh/ruff
-    about: Please consult the documentation before creating an issue.
-  - name: Community
-    url: https://discord.com/invite/astral-sh
-    about: Join our Discord community to ask questions and collaborate.

.github/actionlint.yaml

@@ -1,10 +0,0 @@
-# Configuration for the actionlint tool, which we run via pre-commit
-# to verify the correctness of the syntax in our GitHub Actions workflows.
-
-self-hosted-runner:
-  # Various runners we use that aren't recognized out-of-the-box by actionlint:
-  labels:
-    - depot-ubuntu-latest-8
-    - depot-ubuntu-22.04-16
-    - github-windows-2025-x86_64-8
-    - github-windows-2025-x86_64-16

.github/renovate.json5

@@ -8,55 +8,27 @@
   semanticCommits: "disabled",
   separateMajorMinor: false,
   prHourlyLimit: 10,
-  enabledManagers: ["github-actions", "pre-commit", "cargo", "pep621", "pip_requirements", "npm"],
+  enabledManagers: ["github-actions", "pre-commit", "cargo", "pep621", "npm"],
   cargo: {
     // See https://docs.renovatebot.com/configuration-options/#rangestrategy
     rangeStrategy: "update-lockfile",
   },
   pep621: {
-    // The default for this package manager is to only search for `pyproject.toml` files
-    // found at the repository root: https://docs.renovatebot.com/modules/manager/pep621/#file-matching
     fileMatch: ["^(python|scripts)/.*pyproject\\.toml$"],
   },
-  pip_requirements: {
-    // The default for this package manager is to run on all requirements.txt files:
-    // https://docs.renovatebot.com/modules/manager/pip_requirements/#file-matching
-    // `fileMatch` doesn't work for excluding files; to exclude `requirements.txt` files
-    // outside the `doc/` directory, we instead have to use `ignorePaths`. Unlike `fileMatch`,
-    // which takes a regex string, `ignorePaths` takes a glob string, so we have to use
-    // a "negative glob pattern".
-    // See:
-    // - https://docs.renovatebot.com/modules/manager/#ignoring-files-that-match-the-default-filematch
-    // - https://docs.renovatebot.com/configuration-options/#ignorepaths
-    // - https://docs.renovatebot.com/string-pattern-matching/#negative-matching
-    ignorePaths: ["!docs/requirements*.txt"]
-  },
   npm: {
-    // The default for this package manager is to only search for `package.json` files
-    // found at the repository root: https://docs.renovatebot.com/modules/manager/npm/#file-matching
     fileMatch: ["^playground/.*package\\.json$"],
   },
   "pre-commit": {
     enabled: true,
   },
   packageRules: [
-    // Pin GitHub Actions to immutable SHAs.
-    {
-      matchDepTypes: ["action"],
-      pinDigests: true,
-    },
-    // Annotate GitHub Actions SHAs with a SemVer version.
-    {
-      extends: ["helpers:pinGitHubActionDigests"],
-      extractVersion: "^(?<version>v?\\d+\\.\\d+\\.\\d+)$",
-      versioning: "regex:^v?(?<major>\\d+)(\\.(?<minor>\\d+)\\.(?<patch>\\d+))?$",
-    },
     {
       // Group upload/download artifact updates, the versions are dependent
       groupName: "Artifact GitHub Actions dependencies",
       matchManagers: ["github-actions"],
       matchDatasources: ["gitea-tags", "github-tags"],
-      matchPackageNames: ["actions/.*-artifact"],
+      matchPackagePatterns: ["actions/.*-artifact"],
       description: "Weekly update of artifact-related GitHub Actions dependencies",
     },
     {
@@ -72,18 +44,10 @@
     {
       // Disable updates of `zip-rs`; intentionally pinned for now due to ownership change
       // See: https://github.com/astral-sh/uv/issues/3642
-      matchPackageNames: ["zip"],
+      matchPackagePatterns: ["zip"],
       matchManagers: ["cargo"],
       enabled: false,
     },
-    {
-      // `mkdocs-material` requires a manual update to keep the version in sync
-      // with `mkdocs-material-insider`.
-      // See: https://squidfunk.github.io/mkdocs-material/insiders/upgrade/
-      matchManagers: ["pip_requirements"],
-      matchPackageNames: ["mkdocs-material"],
-      enabled: false,
-    },
     {
       groupName: "pre-commit dependencies",
       matchManagers: ["pre-commit"],
@@ -98,15 +62,22 @@
     {
       groupName: "Monaco",
       matchManagers: ["npm"],
-      matchPackageNames: ["monaco"],
+      matchPackagePatterns: ["monaco"],
       description: "Weekly update of the Monaco editor",
     },
     {
       groupName: "strum",
       matchManagers: ["cargo"],
-      matchPackageNames: ["strum"],
+      matchPackagePatterns: ["strum"],
       description: "Weekly update of strum dependencies",
-    }
+    },
+    {
+      groupName: "ESLint",
+      matchManagers: ["npm"],
+      matchPackageNames: ["eslint"],
+      allowedVersions: "<9",
+      description: "Constraint ESLint to version 8 until TypeScript-eslint supports ESLint 9", // https://github.com/typescript-eslint/typescript-eslint/issues/8211
+    },
   ],
   vulnerabilityAlerts: {
     commitMessageSuffix: "",

.github/workflows/build-binaries.yml

@@ -23,12 +23,10 @@ concurrency:
   group: ${{ github.workflow }}-${{ github.ref }}
   cancel-in-progress: true
 
-permissions: {}
-
 env:
   PACKAGE_NAME: ruff
   MODULE_NAME: ruff
-  PYTHON_VERSION: "3.13"
+  PYTHON_VERSION: "3.11"
   CARGO_INCREMENTAL: 0
   CARGO_NET_RETRY: 10
   CARGO_TERM_COLOR: always
@@ -39,52 +37,50 @@ jobs:
     if: ${{ !contains(github.event.pull_request.labels.*.name, 'no-build') }}
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+      - uses: actions/checkout@v4
         with:
           submodules: recursive
-          persist-credentials: false
-      - uses: actions/setup-python@8d9ed9ac5c53483de85588cdf95a591a75ab9f55 # v5.5.0
+      - uses: actions/setup-python@v5
         with:
           python-version: ${{ env.PYTHON_VERSION }}
       - name: "Prep README.md"
         run: python scripts/transform_readme.py --target pypi
       - name: "Build sdist"
-        uses: PyO3/maturin-action@44479ae1b6b1a57f561e03add8832e62c185eb17 # v1.48.1
+        uses: PyO3/maturin-action@v1
         with:
           command: sdist
           args: --out dist
       - name: "Test sdist"
         run: |
-          pip install dist/"${PACKAGE_NAME}"-*.tar.gz --force-reinstall
-          "${MODULE_NAME}" --help
-          python -m "${MODULE_NAME}" --help
+          pip install dist/${{ env.PACKAGE_NAME }}-*.tar.gz --force-reinstall
+          ${{ env.MODULE_NAME }} --help
+          python -m ${{ env.MODULE_NAME }} --help
       - name: "Upload sdist"
-        uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02 # v4.6.2
+        uses: actions/upload-artifact@v4
         with:
           name: wheels-sdist
           path: dist
 
   macos-x86_64:
     if: ${{ !contains(github.event.pull_request.labels.*.name, 'no-build') }}
-    runs-on: macos-14
+    runs-on: macos-12
     steps:
-      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+      - uses: actions/checkout@v4
         with:
           submodules: recursive
-          persist-credentials: false
-      - uses: actions/setup-python@8d9ed9ac5c53483de85588cdf95a591a75ab9f55 # v5.5.0
+      - uses: actions/setup-python@v5
         with:
           python-version: ${{ env.PYTHON_VERSION }}
           architecture: x64
       - name: "Prep README.md"
         run: python scripts/transform_readme.py --target pypi
       - name: "Build wheels - x86_64"
-        uses: PyO3/maturin-action@44479ae1b6b1a57f561e03add8832e62c185eb17 # v1.48.1
+        uses: PyO3/maturin-action@v1
         with:
           target: x86_64
           args: --release --locked --out dist
       - name: "Upload wheels"
-        uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02 # v4.6.2
+        uses: actions/upload-artifact@v4
         with:
           name: wheels-macos-x86_64
           path: dist
@@ -99,7 +95,7 @@ jobs:
           tar czvf $ARCHIVE_FILE $ARCHIVE_NAME
           shasum -a 256 $ARCHIVE_FILE > $ARCHIVE_FILE.sha256
       - name: "Upload binary"
-        uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02 # v4.6.2
+        uses: actions/upload-artifact@v4
         with:
           name: artifacts-macos-x86_64
           path: |
@@ -110,28 +106,27 @@ jobs:
     if: ${{ !contains(github.event.pull_request.labels.*.name, 'no-build') }}
     runs-on: macos-14
     steps:
-      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+      - uses: actions/checkout@v4
         with:
           submodules: recursive
-          persist-credentials: false
-      - uses: actions/setup-python@8d9ed9ac5c53483de85588cdf95a591a75ab9f55 # v5.5.0
+      - uses: actions/setup-python@v5
         with:
           python-version: ${{ env.PYTHON_VERSION }}
           architecture: arm64
       - name: "Prep README.md"
         run: python scripts/transform_readme.py --target pypi
       - name: "Build wheels - aarch64"
-        uses: PyO3/maturin-action@44479ae1b6b1a57f561e03add8832e62c185eb17 # v1.48.1
+        uses: PyO3/maturin-action@v1
         with:
           target: aarch64
           args: --release --locked --out dist
       - name: "Test wheel - aarch64"
         run: |
-          pip install dist/"${PACKAGE_NAME}"-*.whl --force-reinstall
+          pip install dist/${{ env.PACKAGE_NAME }}-*.whl --force-reinstall
           ruff --help
           python -m ruff --help
       - name: "Upload wheels"
-        uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02 # v4.6.2
+        uses: actions/upload-artifact@v4
         with:
           name: wheels-aarch64-apple-darwin
           path: dist
@@ -146,7 +141,7 @@ jobs:
           tar czvf $ARCHIVE_FILE $ARCHIVE_NAME
           shasum -a 256 $ARCHIVE_FILE > $ARCHIVE_FILE.sha256
       - name: "Upload binary"
-        uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02 # v4.6.2
+        uses: actions/upload-artifact@v4
         with:
           name: artifacts-aarch64-apple-darwin
           path: |
@@ -166,18 +161,17 @@ jobs:
           - target: aarch64-pc-windows-msvc
             arch: x64
     steps:
-      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+      - uses: actions/checkout@v4
         with:
           submodules: recursive
-          persist-credentials: false
-      - uses: actions/setup-python@8d9ed9ac5c53483de85588cdf95a591a75ab9f55 # v5.5.0
+      - uses: actions/setup-python@v5
         with:
           python-version: ${{ env.PYTHON_VERSION }}
           architecture: ${{ matrix.platform.arch }}
       - name: "Prep README.md"
         run: python scripts/transform_readme.py --target pypi
       - name: "Build wheels"
-        uses: PyO3/maturin-action@44479ae1b6b1a57f561e03add8832e62c185eb17 # v1.48.1
+        uses: PyO3/maturin-action@v1
         with:
           target: ${{ matrix.platform.target }}
           args: --release --locked --out dist
@@ -188,11 +182,11 @@ jobs:
         if: ${{ !startsWith(matrix.platform.target, 'aarch64') }}
         shell: bash
         run: |
-          python -m pip install dist/"${PACKAGE_NAME}"-*.whl --force-reinstall
-          "${MODULE_NAME}" --help
-          python -m "${MODULE_NAME}" --help
+          python -m pip install dist/${{ env.PACKAGE_NAME }}-*.whl --force-reinstall
+          ${{ env.MODULE_NAME }} --help
+          python -m ${{ env.MODULE_NAME }} --help
       - name: "Upload wheels"
-        uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02 # v4.6.2
+        uses: actions/upload-artifact@v4
         with:
           name: wheels-${{ matrix.platform.target }}
           path: dist
@@ -203,7 +197,7 @@ jobs:
           7z a $ARCHIVE_FILE ./target/${{ matrix.platform.target }}/release/ruff.exe
           sha256sum $ARCHIVE_FILE > $ARCHIVE_FILE.sha256
       - name: "Upload binary"
-        uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02 # v4.6.2
+        uses: actions/upload-artifact@v4
         with:
           name: artifacts-${{ matrix.platform.target }}
           path: |
@@ -219,18 +213,17 @@ jobs:
           - x86_64-unknown-linux-gnu
           - i686-unknown-linux-gnu
     steps:
-      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+      - uses: actions/checkout@v4
         with:
           submodules: recursive
-          persist-credentials: false
-      - uses: actions/setup-python@8d9ed9ac5c53483de85588cdf95a591a75ab9f55 # v5.5.0
+      - uses: actions/setup-python@v5
         with:
           python-version: ${{ env.PYTHON_VERSION }}
           architecture: x64
       - name: "Prep README.md"
         run: python scripts/transform_readme.py --target pypi
       - name: "Build wheels"
-        uses: PyO3/maturin-action@44479ae1b6b1a57f561e03add8832e62c185eb17 # v1.48.1
+        uses: PyO3/maturin-action@v1
         with:
           target: ${{ matrix.target }}
           manylinux: auto
@@ -238,11 +231,11 @@ jobs:
       - name: "Test wheel"
         if: ${{ startsWith(matrix.target, 'x86_64') }}
         run: |
-          pip install dist/"${PACKAGE_NAME}"-*.whl --force-reinstall
-          "${MODULE_NAME}" --help
-          python -m "${MODULE_NAME}" --help
+          pip install dist/${{ env.PACKAGE_NAME }}-*.whl --force-reinstall
+          ${{ env.MODULE_NAME }} --help
+          python -m ${{ env.MODULE_NAME }} --help
       - name: "Upload wheels"
-        uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02 # v4.6.2
+        uses: actions/upload-artifact@v4
         with:
           name: wheels-${{ matrix.target }}
           path: dist
@@ -260,7 +253,7 @@ jobs:
           tar czvf $ARCHIVE_FILE $ARCHIVE_NAME
           shasum -a 256 $ARCHIVE_FILE > $ARCHIVE_FILE.sha256
       - name: "Upload binary"
-        uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02 # v4.6.2
+        uses: actions/upload-artifact@v4
         with:
           name: artifacts-${{ matrix.target }}
           path: |
@@ -294,24 +287,23 @@ jobs:
             arch: arm
 
     steps:
-      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+      - uses: actions/checkout@v4
         with:
           submodules: recursive
-          persist-credentials: false
-      - uses: actions/setup-python@8d9ed9ac5c53483de85588cdf95a591a75ab9f55 # v5.5.0
+      - uses: actions/setup-python@v5
         with:
           python-version: ${{ env.PYTHON_VERSION }}
       - name: "Prep README.md"
         run: python scripts/transform_readme.py --target pypi
       - name: "Build wheels"
-        uses: PyO3/maturin-action@44479ae1b6b1a57f561e03add8832e62c185eb17 # v1.48.1
+        uses: PyO3/maturin-action@v1
         with:
           target: ${{ matrix.platform.target }}
           manylinux: auto
           docker-options: ${{ matrix.platform.maturin_docker_options }}
           args: --release --locked --out dist
-      - uses: uraimo/run-on-arch-action@ac33288c3728ca72563c97b8b88dda5a65a84448 # v2
-        if: ${{ matrix.platform.arch != 'ppc64' && matrix.platform.arch != 'ppc64le'}}
+      - uses: uraimo/run-on-arch-action@v2
+        if: matrix.platform.arch != 'ppc64'
         name: Test wheel
         with:
           arch: ${{ matrix.platform.arch == 'arm' && 'armv6' || matrix.platform.arch }}
@@ -325,7 +317,7 @@ jobs:
             pip3 install ${{ env.PACKAGE_NAME }} --no-index --find-links dist/ --force-reinstall
             ruff --help
       - name: "Upload wheels"
-        uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02 # v4.6.2
+        uses: actions/upload-artifact@v4
         with:
           name: wheels-${{ matrix.platform.target }}
           path: dist
@@ -343,7 +335,7 @@ jobs:
           tar czvf $ARCHIVE_FILE $ARCHIVE_NAME
           shasum -a 256 $ARCHIVE_FILE > $ARCHIVE_FILE.sha256
       - name: "Upload binary"
-        uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02 # v4.6.2
+        uses: actions/upload-artifact@v4
         with:
           name: artifacts-${{ matrix.platform.target }}
           path: |
@@ -359,18 +351,17 @@ jobs:
           - x86_64-unknown-linux-musl
           - i686-unknown-linux-musl
     steps:
-      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+      - uses: actions/checkout@v4
         with:
           submodules: recursive
-          persist-credentials: false
-      - uses: actions/setup-python@8d9ed9ac5c53483de85588cdf95a591a75ab9f55 # v5.5.0
+      - uses: actions/setup-python@v5
         with:
           python-version: ${{ env.PYTHON_VERSION }}
           architecture: x64
       - name: "Prep README.md"
         run: python scripts/transform_readme.py --target pypi
       - name: "Build wheels"
-        uses: PyO3/maturin-action@44479ae1b6b1a57f561e03add8832e62c185eb17 # v1.48.1
+        uses: PyO3/maturin-action@v1
         with:
           target: ${{ matrix.target }}
           manylinux: musllinux_1_2
@@ -387,7 +378,7 @@ jobs:
             .venv/bin/pip3 install ${{ env.PACKAGE_NAME }} --no-index --find-links dist/ --force-reinstall
             .venv/bin/${{ env.MODULE_NAME }} --help
       - name: "Upload wheels"
-        uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02 # v4.6.2
+        uses: actions/upload-artifact@v4
         with:
           name: wheels-${{ matrix.target }}
           path: dist
@@ -405,7 +396,7 @@ jobs:
           tar czvf $ARCHIVE_FILE $ARCHIVE_NAME
           shasum -a 256 $ARCHIVE_FILE > $ARCHIVE_FILE.sha256
       - name: "Upload binary"
-        uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02 # v4.6.2
+        uses: actions/upload-artifact@v4
         with:
           name: artifacts-${{ matrix.target }}
           path: |
@@ -425,23 +416,22 @@ jobs:
             arch: armv7
 
     steps:
-      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+      - uses: actions/checkout@v4
         with:
           submodules: recursive
-          persist-credentials: false
-      - uses: actions/setup-python@8d9ed9ac5c53483de85588cdf95a591a75ab9f55 # v5.5.0
+      - uses: actions/setup-python@v5
         with:
           python-version: ${{ env.PYTHON_VERSION }}
       - name: "Prep README.md"
         run: python scripts/transform_readme.py --target pypi
       - name: "Build wheels"
-        uses: PyO3/maturin-action@44479ae1b6b1a57f561e03add8832e62c185eb17 # v1.48.1
+        uses: PyO3/maturin-action@v1
         with:
           target: ${{ matrix.platform.target }}
           manylinux: musllinux_1_2
           args: --release --locked --out dist
           docker-options: ${{ matrix.platform.maturin_docker_options }}
-      - uses: uraimo/run-on-arch-action@ac33288c3728ca72563c97b8b88dda5a65a84448 # v2
+      - uses: uraimo/run-on-arch-action@v2
         name: Test wheel
         with:
           arch: ${{ matrix.platform.arch }}
@@ -454,7 +444,7 @@ jobs:
             .venv/bin/pip3 install ${{ env.PACKAGE_NAME }} --no-index --find-links dist/ --force-reinstall
             .venv/bin/${{ env.MODULE_NAME }} --help
       - name: "Upload wheels"
-        uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02 # v4.6.2
+        uses: actions/upload-artifact@v4
         with:
           name: wheels-${{ matrix.platform.target }}
           path: dist
@@ -472,7 +462,7 @@ jobs:
           tar czvf $ARCHIVE_FILE $ARCHIVE_NAME
           shasum -a 256 $ARCHIVE_FILE > $ARCHIVE_FILE.sha256
       - name: "Upload binary"
-        uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02 # v4.6.2
+        uses: actions/upload-artifact@v4
         with:
           name: artifacts-${{ matrix.platform.target }}
           path: |

.github/workflows/build-docker.yml

@@ -17,283 +17,52 @@ on:
     paths:
       - .github/workflows/build-docker.yml
 
-env:
-  RUFF_BASE_IMG: ghcr.io/${{ github.repository_owner }}/ruff
-
 jobs:
-  docker-build:
-    name: Build Docker image (ghcr.io/astral-sh/ruff) for ${{ matrix.platform }}
+  docker-publish:
+    name: Build Docker image (ghcr.io/astral-sh/ruff)
     runs-on: ubuntu-latest
     environment:
       name: release
-    strategy:
-      fail-fast: false
-      matrix:
-        platform:
-          - linux/amd64
-          - linux/arm64
     steps:
-      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+      - uses: actions/checkout@v4
         with:
           submodules: recursive
-          persist-credentials: false
 
-      - uses: docker/setup-buildx-action@b5ca514318bd6ebac0fb2aedd5d36ec1b5c232a2 # v3
+      - uses: docker/setup-buildx-action@v3
 
-      - uses: docker/login-action@74a5d142397b4f367a81961eba4e8cd7edddf772 # v3
+      - uses: docker/login-action@v3
         with:
           registry: ghcr.io
           username: ${{ github.repository_owner }}
           password: ${{ secrets.GITHUB_TOKEN }}
 
+      - name: Extract metadata (tags, labels) for Docker
+        id: meta
+        uses: docker/metadata-action@v5
+        with:
+          images: ghcr.io/astral-sh/ruff
+
       - name: Check tag consistency
         if: ${{ inputs.plan != '' && !fromJson(inputs.plan).announcement_tag_is_implicit }}
-        env:
-          TAG: ${{ inputs.plan != '' && fromJson(inputs.plan).announcement_tag || 'dry-run' }}
         run: |
-          version=$(grep -m 1 "^version = " pyproject.toml | sed -e 's/version = "\(.*\)"/\1/g')
-          if [ "${TAG}" != "${version}" ]; then
+          version=$(grep "version = " pyproject.toml | sed -e 's/version = "\(.*\)"/\1/g')
+          if [ "${{ fromJson(inputs.plan).announcement_tag }}" != "${version}" ]; then
             echo "The input tag does not match the version from pyproject.toml:" >&2
-            echo "${TAG}" >&2
+            echo "${{ fromJson(inputs.plan).announcement_tag }}" >&2
             echo "${version}" >&2
             exit 1
           else
             echo "Releasing ${version}"
           fi
 
-      - name: Extract metadata (tags, labels) for Docker
-        id: meta
-        uses: docker/metadata-action@902fa8ec7d6ecbf8d84d538b9b233a880e428804 # v5
-        with:
-          images: ${{ env.RUFF_BASE_IMG }}
-          # Defining this makes sure the org.opencontainers.image.version OCI label becomes the actual release version and not the branch name
-          tags: |
-            type=raw,value=dry-run,enable=${{ inputs.plan == '' || fromJson(inputs.plan).announcement_tag_is_implicit }}
-            type=pep440,pattern={{ version }},value=${{ inputs.plan != '' && fromJson(inputs.plan).announcement_tag || 'dry-run' }},enable=${{ inputs.plan != '' && !fromJson(inputs.plan).announcement_tag_is_implicit }}
-
-      - name: Normalize Platform Pair (replace / with -)
-        run: |
-          platform=${{ matrix.platform }}
-          echo "PLATFORM_TUPLE=${platform//\//-}" >> "$GITHUB_ENV"
-
-      # Adapted from https://docs.docker.com/build/ci/github-actions/multi-platform/
-      - name: Build and push by digest
-        id: build
-        uses: docker/build-push-action@471d1dc4e07e5cdedd4c2171150001c434f0b7a4 # v6
-        with:
-          context: .
-          platforms: ${{ matrix.platform }}
-          cache-from: type=gha,scope=ruff-${{ env.PLATFORM_TUPLE }}
-          cache-to: type=gha,mode=min,scope=ruff-${{ env.PLATFORM_TUPLE }}
-          labels: ${{ steps.meta.outputs.labels }}
-          outputs: type=image,name=${{ env.RUFF_BASE_IMG }},push-by-digest=true,name-canonical=true,push=${{ inputs.plan != '' && !fromJson(inputs.plan).announcement_tag_is_implicit }}
-
-      - name: Export digests
-        env:
-          digest: ${{ steps.build.outputs.digest }}
-        run: |
-          mkdir -p /tmp/digests
-          touch "/tmp/digests/${digest#sha256:}"
-
-      - name: Upload digests
-        uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02 # v4.6.2
-        with:
-          name: digests-${{ env.PLATFORM_TUPLE }}
-          path: /tmp/digests/*
-          if-no-files-found: error
-          retention-days: 1
-
-  docker-publish:
-    name: Publish Docker image (ghcr.io/astral-sh/ruff)
-    runs-on: ubuntu-latest
-    environment:
-      name: release
-    needs:
-      - docker-build
-    if: ${{ inputs.plan != '' && !fromJson(inputs.plan).announcement_tag_is_implicit }}
-    steps:
-      - name: Download digests
-        uses: actions/download-artifact@95815c38cf2ff2164869cbab79da8d1f422bc89e # v4.2.1
-        with:
-          path: /tmp/digests
-          pattern: digests-*
-          merge-multiple: true
-
-      - uses: docker/setup-buildx-action@b5ca514318bd6ebac0fb2aedd5d36ec1b5c232a2 # v3
-
-      - name: Extract metadata (tags, labels) for Docker
-        id: meta
-        uses: docker/metadata-action@902fa8ec7d6ecbf8d84d538b9b233a880e428804 # v5
-        with:
-          images: ${{ env.RUFF_BASE_IMG }}
-          # Order is on purpose such that the label org.opencontainers.image.version has the first pattern with the full version
-          tags: |
-            type=pep440,pattern={{ version }},value=${{ fromJson(inputs.plan).announcement_tag }}
-            type=pep440,pattern={{ major }}.{{ minor }},value=${{ fromJson(inputs.plan).announcement_tag }}
-
-      - uses: docker/login-action@74a5d142397b4f367a81961eba4e8cd7edddf772 # v3
-        with:
-          registry: ghcr.io
-          username: ${{ github.repository_owner }}
-          password: ${{ secrets.GITHUB_TOKEN }}
-
-      # Adapted from https://docs.docker.com/build/ci/github-actions/multi-platform/
-      - name: Create manifest list and push
-        working-directory: /tmp/digests
-        # The jq command expands the docker/metadata json "tags" array entry to `-t tag1 -t tag2 ...` for each tag in the array
-        # The printf will expand the base image with the `<RUFF_BASE_IMG>@sha256:<sha256> ...` for each sha256 in the directory
-        # The final command becomes `docker buildx imagetools create -t tag1 -t tag2 ... <RUFF_BASE_IMG>@sha256:<sha256_1> <RUFF_BASE_IMG>@sha256:<sha256_2> ...`
-        run: |
-          # shellcheck disable=SC2046
-          docker buildx imagetools create \
-            $(jq -cr '.tags | map("-t " + .) | join(" ")' <<< "$DOCKER_METADATA_OUTPUT_JSON") \
-            $(printf "${RUFF_BASE_IMG}@sha256:%s " *)
-
-  docker-publish-extra:
-    name: Publish additional Docker image based on ${{ matrix.image-mapping }}
-    runs-on: ubuntu-latest
-    environment:
-      name: release
-    needs:
-      - docker-publish
-    if: ${{ inputs.plan != '' && !fromJson(inputs.plan).announcement_tag_is_implicit }}
-    strategy:
-      fail-fast: false
-      matrix:
-        # Mapping of base image followed by a comma followed by one or more base tags (comma separated)
-        # Note, org.opencontainers.image.version label will use the first base tag (use the most specific tag first)
-        image-mapping:
-          - alpine:3.21,alpine3.21,alpine
-          - debian:bookworm-slim,bookworm-slim,debian-slim
-          - buildpack-deps:bookworm,bookworm,debian
-    steps:
-      - uses: docker/setup-buildx-action@b5ca514318bd6ebac0fb2aedd5d36ec1b5c232a2 # v3
-
-      - uses: docker/login-action@74a5d142397b4f367a81961eba4e8cd7edddf772 # v3
-        with:
-          registry: ghcr.io
-          username: ${{ github.repository_owner }}
-          password: ${{ secrets.GITHUB_TOKEN }}
-
-      - name: Generate Dynamic Dockerfile Tags
-        shell: bash
-        env:
-          TAG_VALUE: ${{ fromJson(inputs.plan).announcement_tag }}
-        run: |
-          set -euo pipefail
-
-          # Extract the image and tags from the matrix variable
-          IFS=',' read -r BASE_IMAGE BASE_TAGS <<< "${{ matrix.image-mapping }}"
-
-          # Generate Dockerfile content
-          cat <<EOF > Dockerfile
-          FROM ${BASE_IMAGE}
-          COPY --from=${RUFF_BASE_IMG}:latest /ruff /usr/local/bin/ruff
-          ENTRYPOINT []
-          CMD ["/usr/local/bin/ruff"]
-          EOF
-
-          # Initialize a variable to store all tag docker metadata patterns
-          TAG_PATTERNS=""
-
-          # Loop through all base tags and append its docker metadata pattern to the list
-          # Order is on purpose such that the label org.opencontainers.image.version has the first pattern with the full version
-          IFS=','; for TAG in ${BASE_TAGS}; do
-            TAG_PATTERNS="${TAG_PATTERNS}type=pep440,pattern={{ version }},suffix=-${TAG},value=${TAG_VALUE}\n"
-            TAG_PATTERNS="${TAG_PATTERNS}type=pep440,pattern={{ major }}.{{ minor }},suffix=-${TAG},value=${TAG_VALUE}\n"
-            TAG_PATTERNS="${TAG_PATTERNS}type=raw,value=${TAG}\n"
-          done
-
-          # Remove the trailing newline from the pattern list
-          TAG_PATTERNS="${TAG_PATTERNS%\\n}"
-
-          # Export image cache name
-          echo "IMAGE_REF=${BASE_IMAGE//:/-}" >> "$GITHUB_ENV"
-
-          # Export tag patterns using the multiline env var syntax
-          {
-            echo "TAG_PATTERNS<<EOF"
-            echo -e "${TAG_PATTERNS}"
-            echo EOF
-          } >> "$GITHUB_ENV"
-
-      - name: Extract metadata (tags, labels) for Docker
-        id: meta
-        uses: docker/metadata-action@902fa8ec7d6ecbf8d84d538b9b233a880e428804 # v5
-        # ghcr.io prefers index level annotations
-        env:
-          DOCKER_METADATA_ANNOTATIONS_LEVELS: index
-        with:
-          images: ${{ env.RUFF_BASE_IMG }}
-          flavor: |
-            latest=false
-          tags: |
-            ${{ env.TAG_PATTERNS }}
-
-      - name: Build and push
-        uses: docker/build-push-action@471d1dc4e07e5cdedd4c2171150001c434f0b7a4 # v6
+      - name: "Build and push Docker image"
+        uses: docker/build-push-action@v6
         with:
           context: .
           platforms: linux/amd64,linux/arm64
-          # We do not really need to cache here as the Dockerfile is tiny
-          #cache-from: type=gha,scope=ruff-${{ env.IMAGE_REF }}
-          #cache-to: type=gha,mode=min,scope=ruff-${{ env.IMAGE_REF }}
-          push: true
-          tags: ${{ steps.meta.outputs.tags }}
+          # Reuse the builder
+          cache-from: type=gha
+          cache-to: type=gha,mode=max
+          push: ${{ inputs.plan != '' && !fromJson(inputs.plan).announcement_tag_is_implicit }}
+          tags: ghcr.io/astral-sh/ruff:latest,ghcr.io/astral-sh/ruff:${{ (inputs.plan != '' && fromJson(inputs.plan).announcement_tag) || 'dry-run' }}
           labels: ${{ steps.meta.outputs.labels }}
-          annotations: ${{ steps.meta.outputs.annotations }}
-
-  # This is effectively a duplicate of `docker-publish` to make https://github.com/astral-sh/ruff/pkgs/container/ruff
-  # show the ruff base image first since GitHub always shows the last updated image digests
-  # This works by annotating the original digests (previously non-annotated) which triggers an update to ghcr.io
-  docker-republish:
-    name: Annotate Docker image (ghcr.io/astral-sh/ruff)
-    runs-on: ubuntu-latest
-    environment:
-      name: release
-    needs:
-      - docker-publish-extra
-    if: ${{ inputs.plan != '' && !fromJson(inputs.plan).announcement_tag_is_implicit }}
-    steps:
-      - name: Download digests
-        uses: actions/download-artifact@95815c38cf2ff2164869cbab79da8d1f422bc89e # v4.2.1
-        with:
-          path: /tmp/digests
-          pattern: digests-*
-          merge-multiple: true
-
-      - uses: docker/setup-buildx-action@b5ca514318bd6ebac0fb2aedd5d36ec1b5c232a2 # v3
-
-      - name: Extract metadata (tags, labels) for Docker
-        id: meta
-        uses: docker/metadata-action@902fa8ec7d6ecbf8d84d538b9b233a880e428804 # v5
-        env:
-          DOCKER_METADATA_ANNOTATIONS_LEVELS: index
-        with:
-          images: ${{ env.RUFF_BASE_IMG }}
-          # Order is on purpose such that the label org.opencontainers.image.version has the first pattern with the full version
-          tags: |
-            type=pep440,pattern={{ version }},value=${{ fromJson(inputs.plan).announcement_tag }}
-            type=pep440,pattern={{ major }}.{{ minor }},value=${{ fromJson(inputs.plan).announcement_tag }}
-
-      - uses: docker/login-action@74a5d142397b4f367a81961eba4e8cd7edddf772 # v3
-        with:
-          registry: ghcr.io
-          username: ${{ github.repository_owner }}
-          password: ${{ secrets.GITHUB_TOKEN }}
-
-      # Adapted from https://docs.docker.com/build/ci/github-actions/multi-platform/
-      - name: Create manifest list and push
-        working-directory: /tmp/digests
-        # The readarray part is used to make sure the quoting and special characters are preserved on expansion (e.g. spaces)
-        # The jq command expands the docker/metadata json "tags" array entry to `-t tag1 -t tag2 ...` for each tag in the array
-        # The printf will expand the base image with the `<RUFF_BASE_IMG>@sha256:<sha256> ...` for each sha256 in the directory
-        # The final command becomes `docker buildx imagetools create -t tag1 -t tag2 ... <RUFF_BASE_IMG>@sha256:<sha256_1> <RUFF_BASE_IMG>@sha256:<sha256_2> ...`
-        run: |
-          readarray -t lines <<< "$DOCKER_METADATA_OUTPUT_ANNOTATIONS"; annotations=(); for line in "${lines[@]}"; do annotations+=(--annotation "$line"); done
-
-          # shellcheck disable=SC2046
-          docker buildx imagetools create \
-            "${annotations[@]}" \
-            $(jq -cr '.tags | map("-t " + .) | join(" ")' <<< "$DOCKER_METADATA_OUTPUT_JSON") \
-            $(printf "${RUFF_BASE_IMG}@sha256:%s " *)

.github/workflows/ci.yaml

@@ -1,7 +1,5 @@
 name: CI
 
-permissions: {}
-
 on:
   push:
     branches: [main]
@@ -18,7 +16,7 @@ env:
   CARGO_TERM_COLOR: always
   RUSTUP_MAX_RETRIES: 10
   PACKAGE_NAME: ruff
-  PYTHON_VERSION: "3.13"
+  PYTHON_VERSION: "3.11"
 
 jobs:
   determine_changes:
@@ -26,179 +24,73 @@ jobs:
     runs-on: ubuntu-latest
     outputs:
       # Flag that is raised when any code that affects parser is changed
-      parser: ${{ steps.check_parser.outputs.changed }}
+      parser: ${{ steps.changed.outputs.parser_any_changed }}
       # Flag that is raised when any code that affects linter is changed
-      linter: ${{ steps.check_linter.outputs.changed }}
+      linter: ${{ steps.changed.outputs.linter_any_changed }}
       # Flag that is raised when any code that affects formatter is changed
-      formatter: ${{ steps.check_formatter.outputs.changed }}
+      formatter: ${{ steps.changed.outputs.formatter_any_changed }}
       # Flag that is raised when any code is changed
       # This is superset of the linter and formatter
-      code: ${{ steps.check_code.outputs.changed }}
-      # Flag that is raised when any code that affects the fuzzer is changed
-      fuzz: ${{ steps.check_fuzzer.outputs.changed }}
-      # Flag that is set to "true" when code related to red-knot changes.
-      red_knot: ${{ steps.check_red_knot.outputs.changed }}
-
-      # Flag that is set to "true" when code related to the playground changes.
-      playground: ${{ steps.check_playground.outputs.changed }}
+      code: ${{ steps.changed.outputs.code_any_changed }}
     steps:
-      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+      - uses: actions/checkout@v4
         with:
           fetch-depth: 0
-          persist-credentials: false
 
-      - name: Determine merge base
-        id: merge_base
-        env:
-          BASE_REF: ${{ github.event.pull_request.base.ref || 'main' }}
-        run: |
-          sha=$(git merge-base HEAD "origin/${BASE_REF}")
-          echo "sha=${sha}" >> "$GITHUB_OUTPUT"
+      - uses: tj-actions/changed-files@v44
+        id: changed
+        with:
+          files_yaml: |
+            parser:
+              - Cargo.toml
+              - Cargo.lock
+              - crates/ruff_python_trivia/**
+              - crates/ruff_source_file/**
+              - crates/ruff_text_size/**
+              - crates/ruff_python_ast/**
+              - crates/ruff_python_parser/**
+              - scripts/fuzz-parser/**
+              - .github/workflows/ci.yaml
 
-      - name: Check if the parser code changed
-        id: check_parser
-        env:
-          MERGE_BASE: ${{ steps.merge_base.outputs.sha }}
-        run: |
-          if git diff --quiet "${MERGE_BASE}...HEAD" -- \
-            ':Cargo.toml' \
-            ':Cargo.lock' \
-            ':crates/ruff_python_trivia/**' \
-            ':crates/ruff_source_file/**' \
-            ':crates/ruff_text_size/**' \
-            ':crates/ruff_python_ast/**' \
-            ':crates/ruff_python_parser/**' \
-            ':python/py-fuzzer/**' \
-            ':.github/workflows/ci.yaml' \
-          ; then
-              echo "changed=false" >> "$GITHUB_OUTPUT"
-          else
-              echo "changed=true" >> "$GITHUB_OUTPUT"
-          fi
+            linter:
+              - Cargo.toml
+              - Cargo.lock
+              - crates/**
+              - "!crates/ruff_python_formatter/**"
+              - "!crates/ruff_formatter/**"
+              - "!crates/ruff_dev/**"
+              - scripts/*
+              - python/**
+              - .github/workflows/ci.yaml
 
-      - name: Check if the linter code changed
-        id: check_linter
-        env:
-          MERGE_BASE: ${{ steps.merge_base.outputs.sha }}
-        run: |
-          if git diff --quiet "${MERGE_BASE}...HEAD" -- ':Cargo.toml' \
-            ':Cargo.lock' \
-            ':crates/**' \
-            ':!crates/red_knot*/**' \
-            ':!crates/ruff_python_formatter/**' \
-            ':!crates/ruff_formatter/**' \
-            ':!crates/ruff_dev/**' \
-            ':!crates/ruff_db/**' \
-            ':scripts/*' \
-            ':python/**' \
-            ':.github/workflows/ci.yaml' \
-          ; then
-              echo "changed=false" >> "$GITHUB_OUTPUT"
-          else
-              echo "changed=true" >> "$GITHUB_OUTPUT"
-          fi
+            formatter:
+              - Cargo.toml
+              - Cargo.lock
+              - crates/ruff_python_formatter/**
+              - crates/ruff_formatter/**
+              - crates/ruff_python_trivia/**
+              - crates/ruff_python_ast/**
+              - crates/ruff_source_file/**
+              - crates/ruff_python_index/**
+              - crates/ruff_text_size/**
+              - crates/ruff_python_parser/**
+              - crates/ruff_dev/**
+              - scripts/*
+              - python/**
+              - .github/workflows/ci.yaml
 
-      - name: Check if the formatter code changed
-        id: check_formatter
-        env:
-          MERGE_BASE: ${{ steps.merge_base.outputs.sha }}
-        run: |
-          if git diff --quiet "${MERGE_BASE}...HEAD" -- ':Cargo.toml' \
-            ':Cargo.lock' \
-            ':crates/ruff_python_formatter/**' \
-            ':crates/ruff_formatter/**' \
-            ':crates/ruff_python_trivia/**' \
-            ':crates/ruff_python_ast/**' \
-            ':crates/ruff_source_file/**' \
-            ':crates/ruff_python_index/**' \
-            ':crates/ruff_python_index/**' \
-            ':crates/ruff_text_size/**' \
-            ':crates/ruff_python_parser/**' \
-            ':scripts/*' \
-            ':python/**' \
-            ':.github/workflows/ci.yaml' \
-          ; then
-              echo "changed=false" >> "$GITHUB_OUTPUT"
-          else
-              echo "changed=true" >> "$GITHUB_OUTPUT"
-          fi
-
-      - name: Check if the fuzzer code changed
-        id: check_fuzzer
-        env:
-          MERGE_BASE: ${{ steps.merge_base.outputs.sha }}
-        run: |
-          if git diff --quiet "${MERGE_BASE}...HEAD" -- ':Cargo.toml' \
-            ':Cargo.lock' \
-            ':fuzz/fuzz_targets/**' \
-            ':.github/workflows/ci.yaml' \
-          ; then
-              echo "changed=false" >> "$GITHUB_OUTPUT"
-          else
-              echo "changed=true" >> "$GITHUB_OUTPUT"
-          fi
-
-      - name: Check if there was any code related change
-        id: check_code
-        env:
-          MERGE_BASE: ${{ steps.merge_base.outputs.sha }}
-        run: |
-          if git diff --quiet "${MERGE_BASE}...HEAD" -- ':**' \
-            ':!**/*.md' \
-            ':crates/red_knot_python_semantic/resources/mdtest/**/*.md' \
-            ':!docs/**' \
-            ':!assets/**' \
-            ':.github/workflows/ci.yaml' \
-          ; then
-              echo "changed=false" >> "$GITHUB_OUTPUT"
-          else
-              echo "changed=true" >> "$GITHUB_OUTPUT"
-          fi
-
-      - name: Check if there was any playground related change
-        id: check_playground
-        env:
-          MERGE_BASE: ${{ steps.merge_base.outputs.sha }}
-        run: |
-          if git diff --quiet "${MERGE_BASE}...HEAD" -- \
-            ':playground/**' \
-          ; then
-              echo "changed=false" >> "$GITHUB_OUTPUT"
-          else
-              echo "changed=true" >> "$GITHUB_OUTPUT"
-          fi
-
-      - name: Check if the red-knot code changed
-        id: check_red_knot
-        env:
-          MERGE_BASE: ${{ steps.merge_base.outputs.sha }}
-        run: |
-          if git diff --quiet "${MERGE_BASE}...HEAD" -- \
-            ':Cargo.toml' \
-            ':Cargo.lock' \
-            ':crates/red_knot*/**' \
-            ':crates/ruff_db/**' \
-            ':crates/ruff_annotate_snippets/**' \
-            ':crates/ruff_python_ast/**' \
-            ':crates/ruff_python_parser/**' \
-            ':crates/ruff_python_trivia/**' \
-            ':crates/ruff_source_file/**' \
-            ':crates/ruff_text_size/**' \
-            ':.github/workflows/ci.yaml' \
-          ; then
-              echo "changed=false" >> "$GITHUB_OUTPUT"
-          else
-              echo "changed=true" >> "$GITHUB_OUTPUT"
-          fi
+            code:
+              - "**/*"
+              - "!**/*.md"
+              - "!docs/**"
+              - "!assets/**"
 
   cargo-fmt:
     name: "cargo fmt"
     runs-on: ubuntu-latest
     timeout-minutes: 10
     steps:
-      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
-        with:
-          persist-credentials: false
+      - uses: actions/checkout@v4
       - name: "Install Rust toolchain"
         run: rustup component add rustfmt
       - run: cargo fmt --all --check
@@ -210,50 +102,38 @@ jobs:
     if: ${{ needs.determine_changes.outputs.code == 'true' || github.ref == 'refs/heads/main' }}
     timeout-minutes: 20
     steps:
-      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
-        with:
-          persist-credentials: false
-      - uses: Swatinem/rust-cache@9d47c6ad4b02e050fd481d890b2ea34778fd09d6 # v2.7.8
+      - uses: actions/checkout@v4
       - name: "Install Rust toolchain"
         run: |
           rustup component add clippy
           rustup target add wasm32-unknown-unknown
+      - uses: Swatinem/rust-cache@v2
       - name: "Clippy"
         run: cargo clippy --workspace --all-targets --all-features --locked -- -D warnings
       - name: "Clippy (wasm)"
-        run: cargo clippy -p ruff_wasm -p red_knot_wasm --target wasm32-unknown-unknown --all-features --locked -- -D warnings
+        run: cargo clippy -p ruff_wasm --target wasm32-unknown-unknown --all-features --locked -- -D warnings
 
   cargo-test-linux:
     name: "cargo test (linux)"
-    runs-on: depot-ubuntu-22.04-16
+    runs-on: ubuntu-latest
     needs: determine_changes
-    if: ${{ !contains(github.event.pull_request.labels.*.name, 'no-test') && (needs.determine_changes.outputs.code == 'true' || github.ref == 'refs/heads/main') }}
+    if: ${{ needs.determine_changes.outputs.code == 'true' || github.ref == 'refs/heads/main' }}
     timeout-minutes: 20
     steps:
-      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
-        with:
-          persist-credentials: false
-      - uses: Swatinem/rust-cache@9d47c6ad4b02e050fd481d890b2ea34778fd09d6 # v2.7.8
+      - uses: actions/checkout@v4
       - name: "Install Rust toolchain"
         run: rustup show
       - name: "Install mold"
         uses: rui314/setup-mold@v1
       - name: "Install cargo nextest"
-        uses: taiki-e/install-action@d4635f2de61c8b8104d59cd4aede2060638378cc # v2
+        uses: taiki-e/install-action@v2
         with:
           tool: cargo-nextest
       - name: "Install cargo insta"
-        uses: taiki-e/install-action@d4635f2de61c8b8104d59cd4aede2060638378cc # v2
+        uses: taiki-e/install-action@v2
         with:
           tool: cargo-insta
-      - name: Red-knot mdtests (GitHub annotations)
-        if: ${{ needs.determine_changes.outputs.red_knot == 'true' }}
-        env:
-          NO_COLOR: 1
-          MDTEST_GITHUB_ANNOTATIONS_FORMAT: 1
-        # Ignore errors if this step fails; we want to continue to later steps in the workflow anyway.
-        # This step is just to get nice GitHub annotations on the PR diff in the files-changed tab.
-        run: cargo test -p red_knot_python_semantic --test mdtest || true
+      - uses: Swatinem/rust-cache@v2
       - name: "Run tests"
         shell: bash
         env:
@@ -262,71 +142,32 @@ jobs:
 
       # Check for broken links in the documentation.
       - run: cargo doc --all --no-deps
-        env:
-          RUSTDOCFLAGS: "-D warnings"
-      # Use --document-private-items so that all our doc comments are kept in
-      # sync, not just public items. Eventually we should do this for all
-      # crates; for now add crates here as they are warning-clean to prevent
-      # regression.
-      - run: cargo doc --no-deps -p red_knot_python_semantic -p red_knot -p red_knot_test -p ruff_db --document-private-items
         env:
           # Setting RUSTDOCFLAGS because `cargo doc --check` isn't yet implemented (https://github.com/rust-lang/cargo/issues/10025).
           RUSTDOCFLAGS: "-D warnings"
-      - uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02 # v4.6.2
+      - uses: actions/upload-artifact@v4
         with:
           name: ruff
           path: target/debug/ruff
 
-  cargo-test-linux-release:
-    name: "cargo test (linux, release)"
-    runs-on: depot-ubuntu-22.04-16
-    needs: determine_changes
-    if: ${{ !contains(github.event.pull_request.labels.*.name, 'no-test') && (needs.determine_changes.outputs.code == 'true' || github.ref == 'refs/heads/main') }}
-    timeout-minutes: 20
-    steps:
-      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
-        with:
-          persist-credentials: false
-      - uses: Swatinem/rust-cache@9d47c6ad4b02e050fd481d890b2ea34778fd09d6 # v2.7.8
-      - name: "Install Rust toolchain"
-        run: rustup show
-      - name: "Install mold"
-        uses: rui314/setup-mold@v1
-      - name: "Install cargo nextest"
-        uses: taiki-e/install-action@d4635f2de61c8b8104d59cd4aede2060638378cc # v2
-        with:
-          tool: cargo-nextest
-      - name: "Install cargo insta"
-        uses: taiki-e/install-action@d4635f2de61c8b8104d59cd4aede2060638378cc # v2
-        with:
-          tool: cargo-insta
-      - name: "Run tests"
-        shell: bash
-        env:
-          NEXTEST_PROFILE: "ci"
-        run: cargo insta test --release --all-features --unreferenced reject --test-runner nextest
-
   cargo-test-windows:
     name: "cargo test (windows)"
-    runs-on: github-windows-2025-x86_64-16
+    runs-on: windows-latest
     needs: determine_changes
-    if: ${{ !contains(github.event.pull_request.labels.*.name, 'no-test') && (needs.determine_changes.outputs.code == 'true' || github.ref == 'refs/heads/main') }}
+    if: ${{ needs.determine_changes.outputs.code == 'true' || github.ref == 'refs/heads/main' }}
     timeout-minutes: 20
     steps:
-      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
-        with:
-          persist-credentials: false
-      - uses: Swatinem/rust-cache@9d47c6ad4b02e050fd481d890b2ea34778fd09d6 # v2.7.8
+      - uses: actions/checkout@v4
       - name: "Install Rust toolchain"
         run: rustup show
       - name: "Install cargo nextest"
-        uses: taiki-e/install-action@d4635f2de61c8b8104d59cd4aede2060638378cc # v2
+        uses: taiki-e/install-action@v2
         with:
           tool: cargo-nextest
+      - uses: Swatinem/rust-cache@v2
       - name: "Run tests"
         shell: bash
         env:
-          NEXTEST_PROFILE: "ci"
           # Workaround for <https://github.com/nextest-rs/nextest/issues/1493>.
           RUSTUP_WINDOWS_PATH_ADD_BIN: 1
         run: |
@@ -337,101 +178,85 @@ jobs:
     name: "cargo test (wasm)"
     runs-on: ubuntu-latest
     needs: determine_changes
-    if: ${{ !contains(github.event.pull_request.labels.*.name, 'no-test') && (needs.determine_changes.outputs.code == 'true' || github.ref == 'refs/heads/main') }}
+    if: ${{ needs.determine_changes.outputs.code == 'true' || github.ref == 'refs/heads/main' }}
     timeout-minutes: 10
     steps:
-      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
-        with:
-          persist-credentials: false
-      - uses: Swatinem/rust-cache@9d47c6ad4b02e050fd481d890b2ea34778fd09d6 # v2.7.8
+      - uses: actions/checkout@v4
       - name: "Install Rust toolchain"
         run: rustup target add wasm32-unknown-unknown
-      - uses: actions/setup-node@cdca7365b2dadb8aad0a33bc7601856ffabcc48e # v4.3.0
+      - uses: actions/setup-node@v4
         with:
-          node-version: 20
+          node-version: 18
           cache: "npm"
           cache-dependency-path: playground/package-lock.json
-      - uses: jetli/wasm-pack-action@0d096b08b4e5a7de8c28de67e11e945404e9eefa # v0.4.0
-        with:
-          version: v0.13.1
-      - name: "Test ruff_wasm"
+      - uses: jetli/wasm-pack-action@v0.4.0
+      - uses: Swatinem/rust-cache@v2
+      - name: "Run wasm-pack"
         run: |
           cd crates/ruff_wasm
           wasm-pack test --node
-      - name: "Test red_knot_wasm"
-        run: |
-          cd crates/red_knot_wasm
-          wasm-pack test --node
 
   cargo-build-release:
     name: "cargo build (release)"
     runs-on: macos-latest
-    if: ${{ github.ref == 'refs/heads/main' }}
+    needs: determine_changes
+    if: ${{ needs.determine_changes.outputs.code == 'true' || github.ref == 'refs/heads/main' }}
     timeout-minutes: 20
     steps:
-      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
-        with:
-          persist-credentials: false
-      - uses: Swatinem/rust-cache@9d47c6ad4b02e050fd481d890b2ea34778fd09d6 # v2.7.8
+      - uses: actions/checkout@v4
       - name: "Install Rust toolchain"
         run: rustup show
       - name: "Install mold"
         uses: rui314/setup-mold@v1
+      - uses: Swatinem/rust-cache@v2
       - name: "Build"
         run: cargo build --release --locked
 
   cargo-build-msrv:
     name: "cargo build (msrv)"
-    runs-on: depot-ubuntu-latest-8
+    runs-on: ubuntu-latest
     needs: determine_changes
-    if: ${{ !contains(github.event.pull_request.labels.*.name, 'no-test') && (needs.determine_changes.outputs.code == 'true' || github.ref == 'refs/heads/main') }}
+    if: ${{ needs.determine_changes.outputs.code == 'true' || github.ref == 'refs/heads/main' }}
     timeout-minutes: 20
     steps:
-      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
-        with:
-          persist-credentials: false
-      - uses: SebRollen/toml-action@b1b3628f55fc3a28208d4203ada8b737e9687876 # v1.2.0
+      - uses: actions/checkout@v4
+      - uses: SebRollen/toml-action@v1.2.0
         id: msrv
         with:
           file: "Cargo.toml"
           field: "workspace.package.rust-version"
-      - uses: Swatinem/rust-cache@9d47c6ad4b02e050fd481d890b2ea34778fd09d6 # v2.7.8
       - name: "Install Rust toolchain"
-        env:
-          MSRV: ${{ steps.msrv.outputs.value }}
-        run: rustup default "${MSRV}"
+        run: rustup default ${{ steps.msrv.outputs.value }}
       - name: "Install mold"
         uses: rui314/setup-mold@v1
       - name: "Install cargo nextest"
-        uses: taiki-e/install-action@d4635f2de61c8b8104d59cd4aede2060638378cc # v2
+        uses: taiki-e/install-action@v2
         with:
           tool: cargo-nextest
       - name: "Install cargo insta"
-        uses: taiki-e/install-action@d4635f2de61c8b8104d59cd4aede2060638378cc # v2
+        uses: taiki-e/install-action@v2
         with:
           tool: cargo-insta
+      - uses: Swatinem/rust-cache@v2
       - name: "Run tests"
         shell: bash
         env:
           NEXTEST_PROFILE: "ci"
-          MSRV: ${{ steps.msrv.outputs.value }}
-        run: cargo "+${MSRV}" insta test --all-features --unreferenced reject --test-runner nextest
+        run: cargo +${{ steps.msrv.outputs.value }} insta test --all-features --unreferenced reject --test-runner nextest
 
-  cargo-fuzz-build:
-    name: "cargo fuzz build"
+  cargo-fuzz:
+    name: "cargo fuzz"
     runs-on: ubuntu-latest
     needs: determine_changes
-    if: ${{ github.ref == 'refs/heads/main' || needs.determine_changes.outputs.fuzz == 'true' || needs.determine_changes.outputs.code == 'true' }}
+    if: ${{ needs.determine_changes.outputs.code == 'true' || github.ref == 'refs/heads/main' }}
     timeout-minutes: 10
     steps:
-      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
-        with:
-          persist-credentials: false
-      - uses: Swatinem/rust-cache@9d47c6ad4b02e050fd481d890b2ea34778fd09d6 # v2.7.8
-        with:
-          workspaces: "fuzz -> target"
+      - uses: actions/checkout@v4
       - name: "Install Rust toolchain"
         run: rustup show
+      - uses: Swatinem/rust-cache@v2
+        with:
+          workspaces: "fuzz -> target"
       - name: "Install cargo-binstall"
         uses: cargo-bins/cargo-binstall@main
         with:
@@ -442,63 +267,49 @@ jobs:
       - run: cargo fuzz build -s none
 
   fuzz-parser:
-    name: "fuzz parser"
+    name: "Fuzz the parser"
     runs-on: ubuntu-latest
     needs:
       - cargo-test-linux
       - determine_changes
-    if: ${{ !contains(github.event.pull_request.labels.*.name, 'no-test') && needs.determine_changes.outputs.parser == 'true' }}
+    if: ${{ needs.determine_changes.outputs.parser == 'true' }}
     timeout-minutes: 20
     env:
       FORCE_COLOR: 1
     steps:
-      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+      - uses: actions/checkout@v4
+      - uses: actions/setup-python@v5
         with:
-          persist-credentials: false
-      - uses: astral-sh/setup-uv@0c5e2b8115b80b4c7c5ddf6ffdd634974642d182 # v5.4.1
-      - uses: actions/download-artifact@95815c38cf2ff2164869cbab79da8d1f422bc89e # v4.2.1
+          python-version: ${{ env.PYTHON_VERSION }}
+      - name: Install uv
+        run: curl -LsSf https://astral.sh/uv/install.sh | sh
+      - name: Install Python requirements
+        run: uv pip install -r scripts/fuzz-parser/requirements.txt --system
+      - uses: actions/download-artifact@v4
         name: Download Ruff binary to test
         id: download-cached-binary
         with:
           name: ruff
           path: ruff-to-test
       - name: Fuzz
-        env:
-          DOWNLOAD_PATH: ${{ steps.download-cached-binary.outputs.download-path }}
         run: |
           # Make executable, since artifact download doesn't preserve this
-          chmod +x "${DOWNLOAD_PATH}/ruff"
+          chmod +x ${{ steps.download-cached-binary.outputs.download-path }}/ruff
 
-          (
-            uvx \
-            --python="${PYTHON_VERSION}" \
-            --from=./python/py-fuzzer \
-            fuzz \
-            --test-executable="${DOWNLOAD_PATH}/ruff" \
-            --bin=ruff \
-            0-500
-          )
+          python scripts/fuzz-parser/fuzz.py 0-500 --test-executable ${{ steps.download-cached-binary.outputs.download-path }}/ruff
 
   scripts:
     name: "test scripts"
     runs-on: ubuntu-latest
     needs: determine_changes
-    if: ${{ !contains(github.event.pull_request.labels.*.name, 'no-test') && (needs.determine_changes.outputs.code == 'true' || github.ref == 'refs/heads/main') }}
+    if: ${{ needs.determine_changes.outputs.code == 'true' || github.ref == 'refs/heads/main' }}
     timeout-minutes: 5
     steps:
-      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
-        with:
-          persist-credentials: false
-      - uses: Swatinem/rust-cache@9d47c6ad4b02e050fd481d890b2ea34778fd09d6 # v2.7.8
+      - uses: actions/checkout@v4
       - name: "Install Rust toolchain"
         run: rustup component add rustfmt
-      # Run all code generation scripts, and verify that the current output is
-      # already checked into git.
-      - run: python crates/ruff_python_ast/generate.py
-      - run: python crates/ruff_python_formatter/generate.py
-      - run: test -z "$(git status --porcelain)"
-      # Verify that adding a plugin or rule produces clean code.
-      - run: ./scripts/add_rule.py --name DoTheThing --prefix F --code 999 --linter pyflakes
+      - uses: Swatinem/rust-cache@v2
+      - run: ./scripts/add_rule.py --name DoTheThing --prefix PL --code C0999 --linter pylint
       - run: cargo check
       - run: cargo fmt --all --check
       - run: |
@@ -509,30 +320,28 @@ jobs:
 
   ecosystem:
     name: "ecosystem"
-    runs-on: depot-ubuntu-latest-8
+    runs-on: ubuntu-latest
     needs:
       - cargo-test-linux
       - determine_changes
     # Only runs on pull requests, since that is the only we way we can find the base version for comparison.
     # Ecosystem check needs linter and/or formatter changes.
-    if: ${{ !contains(github.event.pull_request.labels.*.name, 'no-test') && github.event_name == 'pull_request' && needs.determine_changes.outputs.code == 'true' }}
+    if: ${{ github.event_name == 'pull_request' && needs.determine_changes.outputs.code == 'true' }}
     timeout-minutes: 20
     steps:
-      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
-        with:
-          persist-credentials: false
-      - uses: actions/setup-python@8d9ed9ac5c53483de85588cdf95a591a75ab9f55 # v5.5.0
+      - uses: actions/checkout@v4
+      - uses: actions/setup-python@v5
         with:
           python-version: ${{ env.PYTHON_VERSION }}
 
-      - uses: actions/download-artifact@95815c38cf2ff2164869cbab79da8d1f422bc89e # v4.2.1
+      - uses: actions/download-artifact@v4
         name: Download comparison Ruff binary
         id: ruff-target
         with:
           name: ruff
           path: target/debug
 
-      - uses: dawidd6/action-download-artifact@20319c5641d495c8a52e688b7dc5fada6c3a9fbc # v8
+      - uses: dawidd6/action-download-artifact@v6
         name: Download baseline Ruff binary
         with:
           name: ruff
@@ -546,72 +355,64 @@ jobs:
 
       - name: Run `ruff check` stable ecosystem check
         if: ${{ needs.determine_changes.outputs.linter == 'true' }}
-        env:
-          DOWNLOAD_PATH: ${{ steps.ruff-target.outputs.download-path }}
         run: |
           # Make executable, since artifact download doesn't preserve this
-          chmod +x ./ruff "${DOWNLOAD_PATH}/ruff"
+          chmod +x ./ruff ${{ steps.ruff-target.outputs.download-path }}/ruff
 
           # Set pipefail to avoid hiding errors with tee
           set -eo pipefail
 
-          ruff-ecosystem check ./ruff "${DOWNLOAD_PATH}/ruff" --cache ./checkouts --output-format markdown | tee ecosystem-result-check-stable
+          ruff-ecosystem check ./ruff ${{ steps.ruff-target.outputs.download-path }}/ruff --cache ./checkouts --output-format markdown | tee ecosystem-result-check-stable
 
-          cat ecosystem-result-check-stable > "$GITHUB_STEP_SUMMARY"
+          cat ecosystem-result-check-stable > $GITHUB_STEP_SUMMARY
           echo "### Linter (stable)"  > ecosystem-result
           cat ecosystem-result-check-stable >> ecosystem-result
           echo "" >> ecosystem-result
 
       - name: Run `ruff check` preview ecosystem check
         if: ${{ needs.determine_changes.outputs.linter == 'true' }}
-        env:
-          DOWNLOAD_PATH: ${{ steps.ruff-target.outputs.download-path }}
         run: |
           # Make executable, since artifact download doesn't preserve this
-          chmod +x ./ruff "${DOWNLOAD_PATH}/ruff"
+          chmod +x ./ruff ${{ steps.ruff-target.outputs.download-path }}/ruff
 
           # Set pipefail to avoid hiding errors with tee
           set -eo pipefail
 
-          ruff-ecosystem check ./ruff "${DOWNLOAD_PATH}/ruff" --cache ./checkouts --output-format markdown --force-preview | tee ecosystem-result-check-preview
+          ruff-ecosystem check ./ruff ${{ steps.ruff-target.outputs.download-path }}/ruff --cache ./checkouts --output-format markdown --force-preview | tee ecosystem-result-check-preview
 
-          cat ecosystem-result-check-preview > "$GITHUB_STEP_SUMMARY"
+          cat ecosystem-result-check-preview > $GITHUB_STEP_SUMMARY
           echo "### Linter (preview)" >> ecosystem-result
           cat ecosystem-result-check-preview >> ecosystem-result
           echo "" >> ecosystem-result
 
       - name: Run `ruff format` stable ecosystem check
         if: ${{ needs.determine_changes.outputs.formatter == 'true' }}
-        env:
-          DOWNLOAD_PATH: ${{ steps.ruff-target.outputs.download-path }}
         run: |
           # Make executable, since artifact download doesn't preserve this
-          chmod +x ./ruff "${DOWNLOAD_PATH}/ruff"
+          chmod +x ./ruff ${{ steps.ruff-target.outputs.download-path }}/ruff
 
           # Set pipefail to avoid hiding errors with tee
           set -eo pipefail
 
-          ruff-ecosystem format ./ruff "${DOWNLOAD_PATH}/ruff" --cache ./checkouts --output-format markdown | tee ecosystem-result-format-stable
+          ruff-ecosystem format ./ruff ${{ steps.ruff-target.outputs.download-path }}/ruff --cache ./checkouts --output-format markdown | tee ecosystem-result-format-stable
 
-          cat ecosystem-result-format-stable > "$GITHUB_STEP_SUMMARY"
+          cat ecosystem-result-format-stable > $GITHUB_STEP_SUMMARY
           echo "### Formatter (stable)" >> ecosystem-result
           cat ecosystem-result-format-stable >> ecosystem-result
           echo "" >> ecosystem-result
 
       - name: Run `ruff format` preview ecosystem check
         if: ${{ needs.determine_changes.outputs.formatter == 'true' }}
-        env:
-          DOWNLOAD_PATH: ${{ steps.ruff-target.outputs.download-path }}
         run: |
           # Make executable, since artifact download doesn't preserve this
-          chmod +x ./ruff "${DOWNLOAD_PATH}/ruff"
+          chmod +x ./ruff ${{ steps.ruff-target.outputs.download-path }}/ruff
 
           # Set pipefail to avoid hiding errors with tee
           set -eo pipefail
 
-          ruff-ecosystem format ./ruff "${DOWNLOAD_PATH}/ruff" --cache ./checkouts --output-format markdown --force-preview | tee ecosystem-result-format-preview
+          ruff-ecosystem format ./ruff ${{ steps.ruff-target.outputs.download-path }}/ruff --cache ./checkouts --output-format markdown --force-preview | tee ecosystem-result-format-preview
 
-          cat ecosystem-result-format-preview > "$GITHUB_STEP_SUMMARY"
+          cat ecosystem-result-format-preview > $GITHUB_STEP_SUMMARY
           echo "### Formatter (preview)" >> ecosystem-result
           cat ecosystem-result-format-preview >> ecosystem-result
           echo "" >> ecosystem-result
@@ -620,13 +421,13 @@ jobs:
         run: |
           echo ${{ github.event.number }} > pr-number
 
-      - uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02 # v4.6.2
+      - uses: actions/upload-artifact@v4
         name: Upload PR Number
         with:
           name: pr-number
           path: pr-number
 
-      - uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02 # v4.6.2
+      - uses: actions/upload-artifact@v4
         name: Upload Results
         with:
           name: ecosystem-result
@@ -638,9 +439,7 @@ jobs:
     needs: determine_changes
     if: ${{ needs.determine_changes.outputs.code == 'true' || github.ref == 'refs/heads/main' }}
     steps:
-      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
-        with:
-          persist-credentials: false
+      - uses: actions/checkout@v4
       - uses: cargo-bins/cargo-binstall@main
       - run: cargo binstall --no-confirm cargo-shear
       - run: cargo shear
@@ -649,25 +448,22 @@ jobs:
     name: "python package"
     runs-on: ubuntu-latest
     timeout-minutes: 20
-    if: ${{ !contains(github.event.pull_request.labels.*.name, 'no-test') }}
     steps:
-      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
-        with:
-          persist-credentials: false
-      - uses: actions/setup-python@8d9ed9ac5c53483de85588cdf95a591a75ab9f55 # v5.5.0
+      - uses: actions/checkout@v4
+      - uses: actions/setup-python@v5
         with:
           python-version: ${{ env.PYTHON_VERSION }}
           architecture: x64
-      - uses: Swatinem/rust-cache@9d47c6ad4b02e050fd481d890b2ea34778fd09d6 # v2.7.8
+      - uses: Swatinem/rust-cache@v2
       - name: "Prep README.md"
         run: python scripts/transform_readme.py --target pypi
       - name: "Build wheels"
-        uses: PyO3/maturin-action@44479ae1b6b1a57f561e03add8832e62c185eb17 # v1.48.1
+        uses: PyO3/maturin-action@v1
         with:
           args: --out dist
       - name: "Test wheel"
         run: |
-          pip install --force-reinstall --find-links dist "${PACKAGE_NAME}"
+          pip install --force-reinstall --find-links dist ${{ env.PACKAGE_NAME }}
           ruff --help
           python -m ruff --help
       - name: "Remove wheels from cache"
@@ -675,28 +471,32 @@ jobs:
 
   pre-commit:
     name: "pre-commit"
-    runs-on: depot-ubuntu-22.04-16
+    runs-on: ubuntu-latest
     timeout-minutes: 10
     steps:
-      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+      - uses: actions/checkout@v4
+      - uses: actions/setup-python@v5
         with:
-          persist-credentials: false
-      - uses: astral-sh/setup-uv@0c5e2b8115b80b4c7c5ddf6ffdd634974642d182 # v5.4.1
+          python-version: ${{ env.PYTHON_VERSION }}
+      - name: "Install Rust toolchain"
+        run: rustup show
+      - uses: Swatinem/rust-cache@v2
+      - name: "Install pre-commit"
+        run: pip install pre-commit
       - name: "Cache pre-commit"
-        uses: actions/cache@5a3ec84eff668545956fd18022155c47e93e2684 # v4.2.3
+        uses: actions/cache@v4
         with:
           path: ~/.cache/pre-commit
           key: pre-commit-${{ hashFiles('.pre-commit-config.yaml') }}
       - name: "Run pre-commit"
         run: |
-          echo '```console' > "$GITHUB_STEP_SUMMARY"
+          echo '```console' > $GITHUB_STEP_SUMMARY
           # Enable color output for pre-commit and remove it for the summary
-          # Use --hook-stage=manual to enable slower pre-commit hooks that are skipped by default
-          SKIP=cargo-fmt,clippy,dev-generate-all uvx --python="${PYTHON_VERSION}" pre-commit run --all-files --show-diff-on-failure --color=always --hook-stage=manual | \
-            tee >(sed -E 's/\x1B\[([0-9]{1,2}(;[0-9]{1,2})*)?[mGK]//g' >> "$GITHUB_STEP_SUMMARY") >&1
-          exit_code="${PIPESTATUS[0]}"
-          echo '```' >> "$GITHUB_STEP_SUMMARY"
-          exit "$exit_code"
+          SKIP=cargo-fmt,clippy,dev-generate-all pre-commit run --all-files --show-diff-on-failure --color=always | \
+            tee >(sed -E 's/\x1B\[([0-9]{1,2}(;[0-9]{1,2})*)?[mGK]//g' >> $GITHUB_STEP_SUMMARY) >&1
+          exit_code=${PIPESTATUS[0]}
+          echo '```' >> $GITHUB_STEP_SUMMARY
+          exit $exit_code
 
   docs:
     name: "mkdocs"
@@ -705,28 +505,22 @@ jobs:
     env:
       MKDOCS_INSIDERS_SSH_KEY_EXISTS: ${{ secrets.MKDOCS_INSIDERS_SSH_KEY != '' }}
     steps:
-      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
-        with:
-          persist-credentials: false
-      - uses: actions/setup-python@8d9ed9ac5c53483de85588cdf95a591a75ab9f55 # v5.5.0
-        with:
-          python-version: "3.13"
-      - uses: Swatinem/rust-cache@9d47c6ad4b02e050fd481d890b2ea34778fd09d6 # v2.7.8
+      - uses: actions/checkout@v4
+      - uses: actions/setup-python@v5
       - name: "Add SSH key"
         if: ${{ env.MKDOCS_INSIDERS_SSH_KEY_EXISTS == 'true' }}
-        uses: webfactory/ssh-agent@a6f90b1f127823b31d4d4a8d96047790581349bd # v0.9.1
+        uses: webfactory/ssh-agent@v0.9.0
         with:
           ssh-private-key: ${{ secrets.MKDOCS_INSIDERS_SSH_KEY }}
       - name: "Install Rust toolchain"
         run: rustup show
-      - name: Install uv
-        uses: astral-sh/setup-uv@0c5e2b8115b80b4c7c5ddf6ffdd634974642d182 # v5.4.1
+      - uses: Swatinem/rust-cache@v2
       - name: "Install Insiders dependencies"
         if: ${{ env.MKDOCS_INSIDERS_SSH_KEY_EXISTS == 'true' }}
-        run: uv pip install -r docs/requirements-insiders.txt --system
+        run: pip install -r docs/requirements-insiders.txt
       - name: "Install dependencies"
         if: ${{ env.MKDOCS_INSIDERS_SSH_KEY_EXISTS != 'true' }}
-        run: uv pip install -r docs/requirements.txt --system
+        run: pip install -r docs/requirements.txt
       - name: "Update README File"
         run: python scripts/transform_readme.py --target mkdocs
       - name: "Generate docs"
@@ -744,21 +538,20 @@ jobs:
     name: "formatter instabilities and black similarity"
     runs-on: ubuntu-latest
     needs: determine_changes
-    if: ${{ !contains(github.event.pull_request.labels.*.name, 'no-test') && (needs.determine_changes.outputs.formatter == 'true' || github.ref == 'refs/heads/main') }}
+    if: needs.determine_changes.outputs.formatter == 'true' || github.ref == 'refs/heads/main'
     timeout-minutes: 10
     steps:
-      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
-        with:
-          persist-credentials: false
-      - uses: Swatinem/rust-cache@9d47c6ad4b02e050fd481d890b2ea34778fd09d6 # v2.7.8
+      - uses: actions/checkout@v4
       - name: "Install Rust toolchain"
         run: rustup show
-      - name: "Run checks"
+      - name: "Cache rust"
+        uses: Swatinem/rust-cache@v2
+      - name: "Formatter progress"
         run: scripts/formatter_ecosystem_checks.sh
       - name: "Github step summary"
-        run: cat target/formatter-ecosystem/stats.txt > "$GITHUB_STEP_SUMMARY"
+        run: cat target/progress_projects_stats.txt > $GITHUB_STEP_SUMMARY
       - name: "Remove checkouts from cache"
-        run: rm -r target/formatter-ecosystem
+        run: rm -r target/progress_projects
 
   check-ruff-lsp:
     name: "test ruff-lsp"
@@ -767,24 +560,22 @@ jobs:
     needs:
       - cargo-test-linux
       - determine_changes
-    if: ${{ !contains(github.event.pull_request.labels.*.name, 'no-test') && (needs.determine_changes.outputs.code == 'true' || github.ref == 'refs/heads/main') }}
+    if: ${{ needs.determine_changes.outputs.code == 'true' || github.ref == 'refs/heads/main' }}
     steps:
-      - uses: extractions/setup-just@dd310ad5a97d8e7b41793f8ef055398d51ad4de6 # v2
+      - uses: extractions/setup-just@v2
         env:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
 
-      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+      - uses: actions/checkout@v4
         name: "Download ruff-lsp source"
         with:
-          persist-credentials: false
           repository: "astral-sh/ruff-lsp"
 
-      - uses: actions/setup-python@8d9ed9ac5c53483de85588cdf95a591a75ab9f55 # v5.5.0
+      - uses: actions/setup-python@v5
         with:
-          # installation fails on 3.13 and newer
-          python-version: "3.12"
+          python-version: ${{ env.PYTHON_VERSION }}
 
-      - uses: actions/download-artifact@95815c38cf2ff2164869cbab79da8d1f422bc89e # v4.2.1
+      - uses: actions/download-artifact@v4
         name: Download development ruff binary
         id: ruff-target
         with:
@@ -796,76 +587,39 @@ jobs:
           just install
 
       - name: Run ruff-lsp tests
-        env:
-          DOWNLOAD_PATH: ${{ steps.ruff-target.outputs.download-path }}
         run: |
           # Setup development binary
           pip uninstall --yes ruff
-          chmod +x "${DOWNLOAD_PATH}/ruff"
-          export PATH="${DOWNLOAD_PATH}:${PATH}"
+          chmod +x ${{ steps.ruff-target.outputs.download-path }}/ruff
+          export PATH=${{ steps.ruff-target.outputs.download-path }}:$PATH
           ruff version
 
           just test
 
-  check-playground:
-    name: "check playground"
-    runs-on: ubuntu-latest
-    timeout-minutes: 5
-    needs:
-      - determine_changes
-    if: ${{ (needs.determine_changes.outputs.playground == 'true') }}
-    steps:
-      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
-        with:
-          persist-credentials: false
-      - name: "Install Rust toolchain"
-        run: rustup target add wasm32-unknown-unknown
-      - uses: Swatinem/rust-cache@9d47c6ad4b02e050fd481d890b2ea34778fd09d6 # v2.7.8
-      - uses: actions/setup-node@cdca7365b2dadb8aad0a33bc7601856ffabcc48e # v4.3.0
-        with:
-          node-version: 22
-          cache: "npm"
-          cache-dependency-path: playground/package-lock.json
-      - uses: jetli/wasm-bindgen-action@20b33e20595891ab1a0ed73145d8a21fc96e7c29 # v0.2.0
-      - name: "Install Node dependencies"
-        run: npm ci
-        working-directory: playground
-      - name: "Build playgrounds"
-        run: npm run dev:wasm
-        working-directory: playground
-      - name: "Run TypeScript checks"
-        run: npm run check
-        working-directory: playground
-      - name: "Check formatting"
-        run: npm run fmt:check
-        working-directory: playground
-
   benchmarks:
-    runs-on: ubuntu-24.04
+    runs-on: ubuntu-latest
     needs: determine_changes
-    if: ${{ github.repository == 'astral-sh/ruff' && !contains(github.event.pull_request.labels.*.name, 'no-test') && (needs.determine_changes.outputs.code == 'true' || github.ref == 'refs/heads/main') }}
+    if: ${{ github.repository == 'astral-sh/ruff' && (needs.determine_changes.outputs.code == 'true' || github.ref == 'refs/heads/main') }}
     timeout-minutes: 20
     steps:
       - name: "Checkout Branch"
-        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
-        with:
-          persist-credentials: false
-
-      - uses: Swatinem/rust-cache@9d47c6ad4b02e050fd481d890b2ea34778fd09d6 # v2.7.8
+        uses: actions/checkout@v4
 
       - name: "Install Rust toolchain"
         run: rustup show
 
       - name: "Install codspeed"
-        uses: taiki-e/install-action@d4635f2de61c8b8104d59cd4aede2060638378cc # v2
+        uses: taiki-e/install-action@v2
         with:
           tool: cargo-codspeed
 
+      - uses: Swatinem/rust-cache@v2
+
       - name: "Build benchmarks"
         run: cargo codspeed build --features codspeed -p ruff_benchmark
 
       - name: "Run benchmarks"
-        uses: CodSpeedHQ/action@0010eb0ca6e89b80c88e8edaaa07cfe5f3e6664d # v3.5.0
+        uses: CodSpeedHQ/action@v2
         with:
           run: cargo codspeed run
           token: ${{ secrets.CODSPEED_TOKEN }}

.github/workflows/daily_fuzz.yaml

@@ -31,31 +31,25 @@ jobs:
     # Don't run the cron job on forks:
     if: ${{ github.repository == 'astral-sh/ruff' || github.event_name != 'schedule' }}
     steps:
-      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+      - uses: actions/checkout@v4
+      - uses: actions/setup-python@v5
         with:
-          persist-credentials: false
-      - uses: astral-sh/setup-uv@0c5e2b8115b80b4c7c5ddf6ffdd634974642d182 # v5.4.1
+          python-version: "3.12"
+      - name: Install uv
+        run: curl -LsSf https://astral.sh/uv/install.sh | sh
+      - name: Install Python requirements
+        run: uv pip install -r scripts/fuzz-parser/requirements.txt --system
       - name: "Install Rust toolchain"
         run: rustup show
       - name: "Install mold"
         uses: rui314/setup-mold@v1
-      - uses: Swatinem/rust-cache@9d47c6ad4b02e050fd481d890b2ea34778fd09d6 # v2.7.8
+      - uses: Swatinem/rust-cache@v2
       - name: Build ruff
         # A debug build means the script runs slower once it gets started,
         # but this is outweighed by the fact that a release build takes *much* longer to compile in CI
         run: cargo build --locked
       - name: Fuzz
-        run: |
-          # shellcheck disable=SC2046
-          (
-            uvx \
-            --python=3.12 \
-            --from=./python/py-fuzzer \
-            fuzz \
-            --test-executable=target/debug/ruff \
-            --bin=ruff \
-            $(shuf -i 0-9999999999999999999 -n 1000)
-          )
+        run: python scripts/fuzz-parser/fuzz.py $(shuf -i 0-9999999999999999999 -n 1000) --test-executable target/debug/ruff
 
   create-issue-on-failure:
     name: Create an issue if the daily fuzz surfaced any bugs
@@ -65,7 +59,7 @@ jobs:
     permissions:
       issues: write
     steps:
-      - uses: actions/github-script@60a0d83039c74a4aee543508d2ffcb1c3799cdea # v7.0.1
+      - uses: actions/github-script@v7
         with:
           github-token: ${{ secrets.GITHUB_TOKEN }}
           script: |
@@ -73,6 +67,6 @@ jobs:
               owner: "astral-sh",
               repo: "ruff",
               title: `Daily parser fuzz failed on ${new Date().toDateString()}`,
-              body: "Run listed here: https://github.com/${{ github.repository }}/actions/runs/${{ github.run_id }}",
+              body: "Runs listed here: https://github.com/astral-sh/ruff/actions/workflows/daily_fuzz.yml",
               labels: ["bug", "parser", "fuzzer"],
             })

.github/workflows/daily_property_tests.yaml

@@ -1,72 +0,0 @@
-name: Daily property test run
-
-on:
-  workflow_dispatch:
-  schedule:
-    - cron: "0 12 * * *"
-  pull_request:
-    paths:
-      - ".github/workflows/daily_property_tests.yaml"
-
-permissions:
-  contents: read
-
-concurrency:
-  group: ${{ github.workflow }}-${{ github.head_ref || github.run_id }}
-  cancel-in-progress: true
-
-env:
-  CARGO_INCREMENTAL: 0
-  CARGO_NET_RETRY: 10
-  CARGO_TERM_COLOR: always
-  RUSTUP_MAX_RETRIES: 10
-  FORCE_COLOR: 1
-
-jobs:
-  property_tests:
-    name: Property tests
-    runs-on: ubuntu-latest
-    timeout-minutes: 20
-    # Don't run the cron job on forks:
-    if: ${{ github.repository == 'astral-sh/ruff' || github.event_name != 'schedule' }}
-    steps:
-      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
-        with:
-          persist-credentials: false
-      - name: "Install Rust toolchain"
-        run: rustup show
-      - name: "Install mold"
-        uses: rui314/setup-mold@v1
-      - uses: Swatinem/rust-cache@9d47c6ad4b02e050fd481d890b2ea34778fd09d6 # v2.7.8
-      - name: Build Red Knot
-        # A release build takes longer (2 min vs 1 min), but the property tests run much faster in release
-        # mode (1.5 min vs 14 min), so the overall time is shorter with a release build.
-        run: cargo build --locked --release --package red_knot_python_semantic --tests
-      - name: Run property tests
-        shell: bash
-        run: |
-          export QUICKCHECK_TESTS=100000
-          for _ in {1..5}; do
-            cargo test --locked --release --package red_knot_python_semantic -- --ignored list::property_tests
-            cargo test --locked --release --package red_knot_python_semantic -- --ignored types::property_tests::stable
-          done
-
-  create-issue-on-failure:
-    name: Create an issue if the daily property test run surfaced any bugs
-    runs-on: ubuntu-latest
-    needs: property_tests
-    if: ${{ github.repository == 'astral-sh/ruff' && always() && github.event_name == 'schedule' && needs.property_tests.result == 'failure' }}
-    permissions:
-      issues: write
-    steps:
-      - uses: actions/github-script@60a0d83039c74a4aee543508d2ffcb1c3799cdea # v7.0.1
-        with:
-          github-token: ${{ secrets.GITHUB_TOKEN }}
-          script: |
-            await github.rest.issues.create({
-              owner: "astral-sh",
-              repo: "ruff",
-              title: `Daily property test run failed on ${new Date().toDateString()}`,
-              body: "Run listed here: https://github.com/${{ github.repository }}/actions/runs/${{ github.run_id }}",
-              labels: ["bug", "red-knot", "testing"],
-            })

.github/workflows/mypy_primer.yaml

@@ -1,93 +0,0 @@
-name: Run mypy_primer
-
-permissions: {}
-
-on:
-  pull_request:
-    paths:
-      - "crates/red_knot*/**"
-      - "crates/ruff_db"
-      - "crates/ruff_python_ast"
-      - "crates/ruff_python_parser"
-      - ".github/workflows/mypy_primer.yaml"
-      - ".github/workflows/mypy_primer_comment.yaml"
-
-concurrency:
-  group: ${{ github.workflow }}-${{ github.ref_name }}-${{ github.event.pull_request.number || github.sha }}
-  cancel-in-progress: true
-
-env:
-  CARGO_INCREMENTAL: 0
-  CARGO_NET_RETRY: 10
-  CARGO_TERM_COLOR: always
-  RUSTUP_MAX_RETRIES: 10
-
-jobs:
-  mypy_primer:
-    name: Run mypy_primer
-    runs-on: depot-ubuntu-22.04-16
-    timeout-minutes: 20
-    steps:
-      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
-        with:
-          path: ruff
-          fetch-depth: 0
-          persist-credentials: false
-
-      - name: Install the latest version of uv
-        uses: astral-sh/setup-uv@0c5e2b8115b80b4c7c5ddf6ffdd634974642d182 # v5.4.1
-
-      - uses: Swatinem/rust-cache@9d47c6ad4b02e050fd481d890b2ea34778fd09d6 # v2.7.8
-        with:
-          workspaces: "ruff"
-      - name: Install Rust toolchain
-        run: rustup show
-
-      - name: Install mypy_primer
-        run: |
-          uv tool install "git+https://github.com/astral-sh/mypy_primer.git@add-red-knot-support-v5"
-
-      - name: Run mypy_primer
-        shell: bash
-        run: |
-          cd ruff
-
-          echo "new commit"
-          git rev-list --format=%s --max-count=1 "$GITHUB_SHA"
-
-          MERGE_BASE="$(git merge-base "$GITHUB_SHA" "origin/$GITHUB_BASE_REF")"
-          git checkout -b base_commit "$MERGE_BASE"
-          echo "base commit"
-          git rev-list --format=%s --max-count=1 base_commit
-
-          cd ..
-
-          # Allow the exit code to be 0 or 1, only fail for actual mypy_primer crashes/bugs
-          uvx mypy_primer \
-            --repo ruff \
-            --type-checker knot \
-            --old base_commit \
-            --new "$GITHUB_SHA" \
-            --project-selector '/(mypy_primer|black|pyp|git-revise|zipp|arrow|isort|itsdangerous|rich|packaging|pybind11|pyinstrument|typeshed-stats|scrapy|werkzeug|bidict|async-utils)$' \
-            --output concise \
-            --debug > mypy_primer.diff || [ $? -eq 1 ]
-
-          # Output diff with ANSI color codes
-          cat mypy_primer.diff
-
-          # Remove ANSI color codes before uploading
-          sed -ie 's/\x1b\[[0-9;]*m//g' mypy_primer.diff
-
-          echo ${{ github.event.number }} > pr-number
-
-      - name: Upload diff
-        uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02 # v4.6.2
-        with:
-          name: mypy_primer_diff
-          path: mypy_primer.diff
-
-      - name: Upload pr-number
-        uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02 # v4.6.2
-        with:
-          name: pr-number
-          path: pr-number

.github/workflows/mypy_primer_comment.yaml

@@ -1,97 +0,0 @@
-name: PR comment (mypy_primer)
-
-on: # zizmor: ignore[dangerous-triggers]
-  workflow_run:
-    workflows: [Run mypy_primer]
-    types: [completed]
-  workflow_dispatch:
-    inputs:
-      workflow_run_id:
-        description: The mypy_primer workflow that triggers the workflow run
-        required: true
-
-jobs:
-  comment:
-    runs-on: ubuntu-24.04
-    permissions:
-      pull-requests: write
-    steps:
-      - uses: dawidd6/action-download-artifact@20319c5641d495c8a52e688b7dc5fada6c3a9fbc # v8
-        name: Download PR number
-        with:
-          name: pr-number
-          run_id: ${{ github.event.workflow_run.id ||  github.event.inputs.workflow_run_id }}
-          if_no_artifact_found: ignore
-          allow_forks: true
-
-      - name: Parse pull request number
-        id: pr-number
-        run: |
-          if [[ -f pr-number ]]
-          then
-            echo "pr-number=$(<pr-number)" >> "$GITHUB_OUTPUT"
-          fi
-
-      - uses: dawidd6/action-download-artifact@20319c5641d495c8a52e688b7dc5fada6c3a9fbc # v8
-        name: "Download mypy_primer results"
-        id: download-mypy_primer_diff
-        if: steps.pr-number.outputs.pr-number
-        with:
-          name: mypy_primer_diff
-          workflow: mypy_primer.yaml
-          pr: ${{ steps.pr-number.outputs.pr-number }}
-          path: pr/mypy_primer_diff
-          workflow_conclusion: completed
-          if_no_artifact_found: ignore
-          allow_forks: true
-
-      - name: Generate comment content
-        id: generate-comment
-        if: steps.download-mypy_primer_diff.outputs.found_artifact == 'true'
-        run: |
-          # Guard against malicious mypy_primer results that symlink to a secret
-          # file on this runner
-          if [[ -L pr/mypy_primer_diff/mypy_primer.diff ]]
-          then
-              echo "Error: mypy_primer.diff cannot be a symlink"
-              exit 1
-          fi
-
-          # Note this identifier is used to find the comment to update on
-          # subsequent runs
-          echo '<!-- generated-comment mypy_primer -->' >> comment.txt
-
-          echo '## `mypy_primer` results' >> comment.txt
-          if [ -s "pr/mypy_primer_diff/mypy_primer.diff" ]; then
-            echo '<details>' >> comment.txt
-            echo '<summary>Changes were detected when running on open source projects</summary>' >> comment.txt
-            echo '' >> comment.txt
-            echo '```diff' >> comment.txt
-            cat pr/mypy_primer_diff/mypy_primer.diff >> comment.txt
-            echo '```' >> comment.txt
-            echo '</details>' >> comment.txt
-          else
-            echo 'No ecosystem changes detected ✅' >> comment.txt
-          fi
-
-          echo 'comment<<EOF' >> "$GITHUB_OUTPUT"
-          cat comment.txt >> "$GITHUB_OUTPUT"
-          echo 'EOF' >> "$GITHUB_OUTPUT"
-
-      - name: Find existing comment
-        uses: peter-evans/find-comment@3eae4d37986fb5a8592848f6a574fdf654e61f9e # v3
-        if: steps.generate-comment.outcome == 'success'
-        id: find-comment
-        with:
-          issue-number: ${{ steps.pr-number.outputs.pr-number }}
-          comment-author: "github-actions[bot]"
-          body-includes: "<!-- generated-comment mypy_primer -->"
-
-      - name: Create or update comment
-        if: steps.find-comment.outcome == 'success'
-        uses: peter-evans/create-or-update-comment@71345be0265236311c031f5c7866368bd1eff043 # v4
-        with:
-          comment-id: ${{ steps.find-comment.outputs.comment-id }}
-          issue-number: ${{ steps.pr-number.outputs.pr-number }}
-          body-path: comment.txt
-          edit-mode: replace

.github/workflows/notify-dependents.yml

@@ -17,7 +17,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: "Update pre-commit mirror"
-        uses: actions/github-script@60a0d83039c74a4aee543508d2ffcb1c3799cdea # v7.0.1
+        uses: actions/github-script@v7
         with:
           github-token: ${{ secrets.RUFF_PRE_COMMIT_PAT }}
           script: |

.github/workflows/pr-comment.yaml

@@ -10,29 +10,29 @@ on:
         description: The ecosystem workflow that triggers the workflow run
         required: true
 
+permissions:
+  pull-requests: write
+
 jobs:
   comment:
     runs-on: ubuntu-latest
-    permissions:
-      pull-requests: write
     steps:
-      - uses: dawidd6/action-download-artifact@20319c5641d495c8a52e688b7dc5fada6c3a9fbc # v8
+      - uses: dawidd6/action-download-artifact@v6
         name: Download pull request number
         with:
           name: pr-number
           run_id: ${{ github.event.workflow_run.id ||  github.event.inputs.workflow_run_id }}
           if_no_artifact_found: ignore
-          allow_forks: true
 
       - name: Parse pull request number
         id: pr-number
         run: |
           if [[ -f pr-number ]]
           then
-            echo "pr-number=$(<pr-number)" >> "$GITHUB_OUTPUT"
+            echo "pr-number=$(<pr-number)" >> $GITHUB_OUTPUT
           fi
 
-      - uses: dawidd6/action-download-artifact@20319c5641d495c8a52e688b7dc5fada6c3a9fbc # v8
+      - uses: dawidd6/action-download-artifact@v6
         name: "Download ecosystem results"
         id: download-ecosystem-result
         if: steps.pr-number.outputs.pr-number
@@ -43,7 +43,6 @@ jobs:
           path: pr/ecosystem
           workflow_conclusion: completed
           if_no_artifact_found: ignore
-          allow_forks: true
 
       - name: Generate comment content
         id: generate-comment
@@ -65,12 +64,12 @@ jobs:
           cat pr/ecosystem/ecosystem-result >> comment.txt
           echo "" >> comment.txt
 
-          echo 'comment<<EOF' >> "$GITHUB_OUTPUT"
-          cat comment.txt >> "$GITHUB_OUTPUT"
-          echo 'EOF' >> "$GITHUB_OUTPUT"
+          echo 'comment<<EOF' >> $GITHUB_OUTPUT
+          cat comment.txt >> $GITHUB_OUTPUT
+          echo 'EOF' >> $GITHUB_OUTPUT
 
       - name: Find existing comment
-        uses: peter-evans/find-comment@3eae4d37986fb5a8592848f6a574fdf654e61f9e # v3
+        uses: peter-evans/find-comment@v3
         if: steps.generate-comment.outcome == 'success'
         id: find-comment
         with:
@@ -80,7 +79,7 @@ jobs:
 
       - name: Create or update comment
         if: steps.find-comment.outcome == 'success'
-        uses: peter-evans/create-or-update-comment@71345be0265236311c031f5c7866368bd1eff043 # v4
+        uses: peter-evans/create-or-update-comment@v4
         with:
           comment-id: ${{ steps.find-comment.outputs.comment-id }}
           issue-number: ${{ steps.pr-number.outputs.pr-number }}

.github/workflows/publish-docs.yml

@@ -21,124 +21,42 @@ jobs:
   mkdocs:
     runs-on: ubuntu-latest
     env:
+      CF_API_TOKEN_EXISTS: ${{ secrets.CF_API_TOKEN != '' }}
       MKDOCS_INSIDERS_SSH_KEY_EXISTS: ${{ secrets.MKDOCS_INSIDERS_SSH_KEY != '' }}
     steps:
-      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+      - uses: actions/checkout@v4
         with:
           ref: ${{ inputs.ref }}
-          persist-credentials: true
-
-      - uses: actions/setup-python@8d9ed9ac5c53483de85588cdf95a591a75ab9f55 # v5.5.0
-        with:
-          python-version: 3.12
-
-      - name: "Set docs version"
-        env:
-          version: ${{ (inputs.plan != '' && fromJson(inputs.plan).announcement_tag) || inputs.ref }}
-        run: |
-          # if version is missing, use 'latest'
-          if [ -z "$version" ]; then
-            echo "Using 'latest' as version"
-            version="latest"
-          fi
-
-          # Use version as display name for now
-          display_name="$version"
-
-          echo "version=$version" >> "$GITHUB_ENV"
-          echo "display_name=$display_name" >> "$GITHUB_ENV"
-
-      - name: "Set branch name"
-        run: |
-          timestamp="$(date +%s)"
-
-          # create branch_display_name from display_name by replacing all
-          # characters disallowed in git branch names with hyphens
-          branch_display_name="$(echo "${display_name}" | tr -c '[:alnum:]._' '-' | tr -s '-')"
-
-          echo "branch_name=update-docs-$branch_display_name-$timestamp" >> "$GITHUB_ENV"
-          echo "timestamp=$timestamp" >> "$GITHUB_ENV"
-
+      - uses: actions/setup-python@v5
       - name: "Add SSH key"
         if: ${{ env.MKDOCS_INSIDERS_SSH_KEY_EXISTS == 'true' }}
-        uses: webfactory/ssh-agent@a6f90b1f127823b31d4d4a8d96047790581349bd # v0.9.1
+        uses: webfactory/ssh-agent@v0.9.0
         with:
           ssh-private-key: ${{ secrets.MKDOCS_INSIDERS_SSH_KEY }}
-
       - name: "Install Rust toolchain"
         run: rustup show
-
-      - uses: Swatinem/rust-cache@9d47c6ad4b02e050fd481d890b2ea34778fd09d6 # v2.7.8
-
+      - uses: Swatinem/rust-cache@v2
       - name: "Install Insiders dependencies"
         if: ${{ env.MKDOCS_INSIDERS_SSH_KEY_EXISTS == 'true' }}
         run: pip install -r docs/requirements-insiders.txt
-
       - name: "Install dependencies"
         if: ${{ env.MKDOCS_INSIDERS_SSH_KEY_EXISTS != 'true' }}
         run: pip install -r docs/requirements.txt
-
       - name: "Copy README File"
         run: |
           python scripts/transform_readme.py --target mkdocs
           python scripts/generate_mkdocs.py
-
       - name: "Build Insiders docs"
         if: ${{ env.MKDOCS_INSIDERS_SSH_KEY_EXISTS == 'true' }}
         run: mkdocs build --strict -f mkdocs.insiders.yml
-
       - name: "Build docs"
         if: ${{ env.MKDOCS_INSIDERS_SSH_KEY_EXISTS != 'true' }}
         run: mkdocs build --strict -f mkdocs.public.yml
-
-      - name: "Clone docs repo"
-        run: git clone https://${{ secrets.ASTRAL_DOCS_PAT }}@github.com/astral-sh/docs.git astral-docs
-
-      - name: "Copy docs"
-        run: rm -rf astral-docs/site/ruff && mkdir -p astral-docs/site && cp -r site/ruff astral-docs/site/
-
-      - name: "Commit docs"
-        working-directory: astral-docs
-        run: |
-          git config user.name "astral-docs-bot"
-          git config user.email "176161322+astral-docs-bot@users.noreply.github.com"
-
-          git checkout -b "${branch_name}"
-          git add site/ruff
-          git commit -m "Update ruff documentation for $version"
-
-      - name: "Create Pull Request"
-        working-directory: astral-docs
-        env:
-          GITHUB_TOKEN: ${{ secrets.ASTRAL_DOCS_PAT }}
-        run: |
-          # set the PR title
-          pull_request_title="Update ruff documentation for ${display_name}"
-
-          # Delete any existing pull requests that are open for this version
-          # by checking against pull_request_title because the new PR will
-          # supersede the old one.
-          gh pr list --state open --json title --jq '.[] | select(.title == "$pull_request_title") | .number' | \
-            xargs -I {} gh pr close {}
-
-          # push the branch to GitHub
-          git push origin "${branch_name}"
-
-          # create the PR
-          gh pr create \
-            --base=main \
-            --head="${branch_name}" \
-            --title="${pull_request_title}" \
-            --body="Automated documentation update for ${display_name}" \
-            --label="documentation"
-
-      - name: "Merge Pull Request"
-        if: ${{ inputs.plan != '' && !fromJson(inputs.plan).announcement_tag_is_implicit }}
-        working-directory: astral-docs
-        env:
-          GITHUB_TOKEN: ${{ secrets.ASTRAL_DOCS_PAT }}
-        run: |
-          # auto-merge the PR if the build was triggered by a release. Manual builds should be reviewed by a human.
-          # give the PR a few seconds to be created before trying to auto-merge it
-          sleep 10
-          gh pr merge --squash "${branch_name}"
+      - name: "Deploy to Cloudflare Pages"
+        if: ${{ env.CF_API_TOKEN_EXISTS == 'true' }}
+        uses: cloudflare/wrangler-action@v3.7.0
+        with:
+          apiToken: ${{ secrets.CF_API_TOKEN }}
+          accountId: ${{ secrets.CF_ACCOUNT_ID }}
+          # `github.head_ref` is only set during pull requests and for manual runs or tags we use `main` to deploy to production
+          command: pages deploy site --project-name=astral-docs --branch ${{ github.head_ref || 'main' }} --commit-hash ${GITHUB_SHA}

.github/workflows/publish-knot-playground.yml

@@ -1,58 +0,0 @@
-# Publish the Red Knot playground.
-name: "[Knot Playground] Release"
-
-permissions: {}
-
-on:
-  push:
-    branches: [main]
-    paths:
-      - "crates/red_knot*/**"
-      - "crates/ruff_db/**"
-      - "crates/ruff_python_ast/**"
-      - "crates/ruff_python_parser/**"
-      - "playground/**"
-      - ".github/workflows/publish-knot-playground.yml"
-
-concurrency:
-  group: ${{ github.workflow }}-${{ github.ref_name }}
-  cancel-in-progress: true
-
-env:
-  CARGO_INCREMENTAL: 0
-  CARGO_NET_RETRY: 10
-  CARGO_TERM_COLOR: always
-  RUSTUP_MAX_RETRIES: 10
-
-jobs:
-  publish:
-    runs-on: ubuntu-latest
-    env:
-      CF_API_TOKEN_EXISTS: ${{ secrets.CF_API_TOKEN != '' }}
-    steps:
-      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
-        with:
-          persist-credentials: false
-      - name: "Install Rust toolchain"
-        run: rustup target add wasm32-unknown-unknown
-      - uses: actions/setup-node@cdca7365b2dadb8aad0a33bc7601856ffabcc48e # v4.3.0
-        with:
-          node-version: 22
-      - uses: jetli/wasm-bindgen-action@20b33e20595891ab1a0ed73145d8a21fc96e7c29 # v0.2.0
-      - name: "Install Node dependencies"
-        run: npm ci
-        working-directory: playground
-      - name: "Run TypeScript checks"
-        run: npm run check
-        working-directory: playground
-      - name: "Build Knot playground"
-        run: npm run build --workspace knot-playground
-        working-directory: playground
-      - name: "Deploy to Cloudflare Pages"
-        if: ${{ env.CF_API_TOKEN_EXISTS == 'true' }}
-        uses: cloudflare/wrangler-action@da0e0dfe58b7a431659754fdf3f186c529afbe65 # v3.14.1
-        with:
-          apiToken: ${{ secrets.CF_API_TOKEN }}
-          accountId: ${{ secrets.CF_ACCOUNT_ID }}
-          # `github.head_ref` is only set during pull requests and for manual runs or tags we use `main` to deploy to production
-          command: pages deploy playground/knot/dist --project-name=knot-playground --branch ${{ github.head_ref || 'main' }} --commit-hash ${GITHUB_SHA}

.github/workflows/publish-playground.yml

@@ -24,31 +24,32 @@ jobs:
     env:
       CF_API_TOKEN_EXISTS: ${{ secrets.CF_API_TOKEN != '' }}
     steps:
-      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
-        with:
-          persist-credentials: false
+      - uses: actions/checkout@v4
       - name: "Install Rust toolchain"
         run: rustup target add wasm32-unknown-unknown
-      - uses: actions/setup-node@cdca7365b2dadb8aad0a33bc7601856ffabcc48e # v4.3.0
+      - uses: actions/setup-node@v4
         with:
-          node-version: 22
+          node-version: 18
           cache: "npm"
           cache-dependency-path: playground/package-lock.json
-      - uses: jetli/wasm-bindgen-action@20b33e20595891ab1a0ed73145d8a21fc96e7c29 # v0.2.0
+      - uses: jetli/wasm-pack-action@v0.4.0
+      - uses: jetli/wasm-bindgen-action@v0.2.0
+      - name: "Run wasm-pack"
+        run: wasm-pack build --target web --out-dir ../../playground/src/pkg crates/ruff_wasm
       - name: "Install Node dependencies"
         run: npm ci
         working-directory: playground
       - name: "Run TypeScript checks"
         run: npm run check
         working-directory: playground
-      - name: "Build Ruff playground"
-        run: npm run build --workspace ruff-playground
+      - name: "Build JavaScript bundle"
+        run: npm run build
         working-directory: playground
       - name: "Deploy to Cloudflare Pages"
         if: ${{ env.CF_API_TOKEN_EXISTS == 'true' }}
-        uses: cloudflare/wrangler-action@da0e0dfe58b7a431659754fdf3f186c529afbe65 # v3.14.1
+        uses: cloudflare/wrangler-action@v3.7.0
         with:
           apiToken: ${{ secrets.CF_API_TOKEN }}
           accountId: ${{ secrets.CF_ACCOUNT_ID }}
           # `github.head_ref` is only set during pull requests and for manual runs or tags we use `main` to deploy to production
-          command: pages deploy playground/ruff/dist --project-name=ruff-playground --branch ${{ github.head_ref || 'main' }} --commit-hash ${GITHUB_SHA}
+          command: pages deploy playground/dist --project-name=ruff-playground --branch ${{ github.head_ref || 'main' }} --commit-hash ${GITHUB_SHA}

.github/workflows/publish-pypi.yml

@@ -21,12 +21,14 @@ jobs:
       # For PyPI's trusted publishing.
       id-token: write
     steps:
-      - name: "Install uv"
-        uses: astral-sh/setup-uv@0c5e2b8115b80b4c7c5ddf6ffdd634974642d182 # v5.4.1
-      - uses: actions/download-artifact@95815c38cf2ff2164869cbab79da8d1f422bc89e # v4.2.1
+      - uses: actions/download-artifact@v4
         with:
           pattern: wheels-*
           path: wheels
           merge-multiple: true
       - name: Publish to PyPi
-        run: uv publish -v wheels/*
+        uses: pypa/gh-action-pypi-publish@release/v1
+        with:
+          skip-existing: true
+          packages-dir: wheels
+          verbose: true

.github/workflows/publish-wasm.yml

@@ -1,59 +0,0 @@
-# Build and publish ruff-api for wasm.
-#
-# Assumed to run as a subworkflow of .github/workflows/release.yml; specifically, as a publish
-# job within `cargo-dist`.
-name: "Build and publish wasm"
-
-on:
-  workflow_dispatch:
-  workflow_call:
-    inputs:
-      plan:
-        required: true
-        type: string
-
-env:
-  CARGO_INCREMENTAL: 0
-  CARGO_NET_RETRY: 10
-  CARGO_TERM_COLOR: always
-  RUSTUP_MAX_RETRIES: 10
-
-jobs:
-  ruff_wasm:
-    runs-on: ubuntu-latest
-    permissions:
-      contents: read
-      id-token: write
-    strategy:
-      matrix:
-        target: [web, bundler, nodejs]
-      fail-fast: false
-    steps:
-      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
-        with:
-          persist-credentials: false
-      - name: "Install Rust toolchain"
-        run: rustup target add wasm32-unknown-unknown
-      - uses: jetli/wasm-pack-action@0d096b08b4e5a7de8c28de67e11e945404e9eefa # v0.4.0
-        with:
-          version: v0.13.1
-      - uses: jetli/wasm-bindgen-action@20b33e20595891ab1a0ed73145d8a21fc96e7c29 # v0.2.0
-      - name: "Run wasm-pack build"
-        run: wasm-pack build --target ${{ matrix.target }} crates/ruff_wasm
-      - name: "Rename generated package"
-        run: | # Replace the package name w/ jq
-          jq '.name="@astral-sh/ruff-wasm-${{ matrix.target }}"' crates/ruff_wasm/pkg/package.json > /tmp/package.json
-          mv /tmp/package.json crates/ruff_wasm/pkg
-      - run: cp LICENSE crates/ruff_wasm/pkg # wasm-pack does not put the LICENSE file in the pkg
-      - uses: actions/setup-node@cdca7365b2dadb8aad0a33bc7601856ffabcc48e # v4.3.0
-        with:
-          node-version: 20
-          registry-url: "https://registry.npmjs.org"
-      - name: "Publish (dry-run)"
-        if: ${{ inputs.plan == '' || fromJson(inputs.plan).announcement_tag_is_implicit }}
-        run: npm publish --dry-run crates/ruff_wasm/pkg
-      - name: "Publish"
-        if: ${{ inputs.plan != '' && !fromJson(inputs.plan).announcement_tag_is_implicit }}
-        run: npm publish --provenance --access public crates/ruff_wasm/pkg
-        env:
-          NODE_AUTH_TOKEN: ${{ secrets.NPM_TOKEN }}

.github/workflows/release.yml

@@ -1,13 +1,10 @@
-# This file was autogenerated by dist: https://github.com/astral-sh/cargo-dist
-#
 # Copyright 2022-2024, axodotdev
-# Copyright 2025 Astral Software Inc.
 # SPDX-License-Identifier: MIT or Apache-2.0
 #
 # CI that:
 #
 # * checks for a Git Tag that looks like a release
-# * builds artifacts with dist (archives, installers, hashes)
+# * builds artifacts with cargo-dist (archives, installers, hashes)
 # * uploads those artifacts to temporary workflow zip
 # * on success, uploads the artifacts to a GitHub Release
 #
@@ -25,10 +22,10 @@ permissions:
 # must be a Cargo-style SemVer Version (must have at least major.minor.patch).
 #
 # If PACKAGE_NAME is specified, then the announcement will be for that
-# package (erroring out if it doesn't have the given version or isn't dist-able).
+# package (erroring out if it doesn't have the given version or isn't cargo-dist-able).
 #
 # If PACKAGE_NAME isn't specified, then the announcement will be for all
-# (dist-able) packages in the workspace with that version (this mode is
+# (cargo-dist-able) packages in the workspace with that version (this mode is
 # intended for workspaces with only one dist-able package, or with all dist-able
 # packages versioned/released in lockstep).
 #
@@ -49,9 +46,9 @@ on:
         type: string
 
 jobs:
-  # Run 'dist plan' (or host) to determine what tasks we need to do
+  # Run 'cargo dist plan' (or host) to determine what tasks we need to do
   plan:
-    runs-on: "depot-ubuntu-latest-4"
+    runs-on: "ubuntu-20.04"
     outputs:
       val: ${{ steps.plan.outputs.manifest }}
       tag: ${{ (inputs.tag != 'dry-run' && inputs.tag) || '' }}
@@ -60,20 +57,19 @@ jobs:
     env:
       GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
     steps:
-      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683
+      - uses: actions/checkout@v4
         with:
-          persist-credentials: false
           submodules: recursive
-      - name: Install dist
+      - name: Install cargo-dist
         # we specify bash to get pipefail; it guards against the `curl` command
         # failing. otherwise `sh` won't catch that `curl` returned non-0
         shell: bash
-        run: "curl --proto '=https' --tlsv1.2 -LsSf https://github.com/astral-sh/cargo-dist/releases/download/v0.28.4-prerelease.1/cargo-dist-installer.sh | sh"
-      - name: Cache dist
-        uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02
+        run: "curl --proto '=https' --tlsv1.2 -LsSf https://github.com/axodotdev/cargo-dist/releases/download/v0.18.0/cargo-dist-installer.sh | sh"
+      - name: Cache cargo-dist
+        uses: actions/upload-artifact@v4
         with:
           name: cargo-dist-cache
-          path: ~/.cargo/bin/dist
+          path: ~/.cargo/bin/cargo-dist
       # sure would be cool if github gave us proper conditionals...
       # so here's a doubly-nested ternary-via-truthiness to try to provide the best possible
       # functionality based on whether this is a pull_request, and whether it's from a fork.
@@ -81,12 +77,12 @@ jobs:
       # but also really annoying to build CI around when it needs secrets to work right.)
       - id: plan
         run: |
-          dist ${{ (inputs.tag && inputs.tag != 'dry-run' && format('host --steps=create --tag={0}', inputs.tag)) || 'plan' }} --output-format=json > plan-dist-manifest.json
-          echo "dist ran successfully"
+          cargo dist ${{ (inputs.tag && inputs.tag != 'dry-run' && format('host --steps=create --tag={0}', inputs.tag)) || 'plan' }} --output-format=json > plan-dist-manifest.json
+          echo "cargo dist ran successfully"
           cat plan-dist-manifest.json
           echo "manifest=$(jq -c "." plan-dist-manifest.json)" >> "$GITHUB_OUTPUT"
       - name: "Upload dist-manifest.json"
-        uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02
+        uses: actions/upload-artifact@v4
         with:
           name: artifacts-plan-dist-manifest
           path: plan-dist-manifest.json
@@ -118,24 +114,23 @@ jobs:
       - plan
       - custom-build-binaries
       - custom-build-docker
-    runs-on: "depot-ubuntu-latest-4"
+    runs-on: "ubuntu-20.04"
     env:
       GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
       BUILD_MANIFEST_NAME: target/distrib/global-dist-manifest.json
     steps:
-      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683
+      - uses: actions/checkout@v4
         with:
-          persist-credentials: false
           submodules: recursive
-      - name: Install cached dist
-        uses: actions/download-artifact@95815c38cf2ff2164869cbab79da8d1f422bc89e
+      - name: Install cached cargo-dist
+        uses: actions/download-artifact@v4
         with:
           name: cargo-dist-cache
           path: ~/.cargo/bin/
-      - run: chmod +x ~/.cargo/bin/dist
+      - run: chmod +x ~/.cargo/bin/cargo-dist
       # Get all the local artifacts for the global tasks to use (for e.g. checksums)
       - name: Fetch local artifacts
-        uses: actions/download-artifact@95815c38cf2ff2164869cbab79da8d1f422bc89e
+        uses: actions/download-artifact@v4
         with:
           pattern: artifacts-*
           path: target/distrib/
@@ -143,8 +138,8 @@ jobs:
       - id: cargo-dist
         shell: bash
         run: |
-          dist build ${{ needs.plan.outputs.tag-flag }} --output-format=json "--artifacts=global" > dist-manifest.json
-          echo "dist ran successfully"
+          cargo dist build ${{ needs.plan.outputs.tag-flag }} --output-format=json "--artifacts=global" > dist-manifest.json
+          echo "cargo dist ran successfully"
 
           # Parse out what we just built and upload it to scratch storage
           echo "paths<<EOF" >> "$GITHUB_OUTPUT"
@@ -153,7 +148,7 @@ jobs:
 
           cp dist-manifest.json "$BUILD_MANIFEST_NAME"
       - name: "Upload artifacts"
-        uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02
+        uses: actions/upload-artifact@v4
         with:
           name: artifacts-build-global
           path: |
@@ -170,23 +165,22 @@ jobs:
     if: ${{ always() && needs.plan.outputs.publishing == 'true' && (needs.build-global-artifacts.result == 'skipped' || needs.build-global-artifacts.result == 'success') && (needs.custom-build-binaries.result == 'skipped' || needs.custom-build-binaries.result == 'success') && (needs.custom-build-docker.result == 'skipped' || needs.custom-build-docker.result == 'success') }}
     env:
       GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
-    runs-on: "depot-ubuntu-latest-4"
+    runs-on: "ubuntu-20.04"
     outputs:
       val: ${{ steps.host.outputs.manifest }}
     steps:
-      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683
+      - uses: actions/checkout@v4
         with:
-          persist-credentials: false
           submodules: recursive
-      - name: Install cached dist
-        uses: actions/download-artifact@95815c38cf2ff2164869cbab79da8d1f422bc89e
+      - name: Install cached cargo-dist
+        uses: actions/download-artifact@v4
         with:
           name: cargo-dist-cache
           path: ~/.cargo/bin/
-      - run: chmod +x ~/.cargo/bin/dist
+      - run: chmod +x ~/.cargo/bin/cargo-dist
       # Fetch artifacts from scratch-storage
       - name: Fetch artifacts
-        uses: actions/download-artifact@95815c38cf2ff2164869cbab79da8d1f422bc89e
+        uses: actions/download-artifact@v4
         with:
           pattern: artifacts-*
           path: target/distrib/
@@ -195,12 +189,12 @@ jobs:
       - id: host
         shell: bash
         run: |
-          dist host ${{ needs.plan.outputs.tag-flag }} --steps=upload --steps=release --output-format=json > dist-manifest.json
+          cargo dist host ${{ needs.plan.outputs.tag-flag }} --steps=upload --steps=release --output-format=json > dist-manifest.json
           echo "artifacts uploaded and released successfully"
           cat dist-manifest.json
           echo "manifest=$(jq -c "." dist-manifest.json)" >> "$GITHUB_OUTPUT"
       - name: "Upload dist-manifest.json"
-        uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02
+        uses: actions/upload-artifact@v4
         with:
           # Overwrite the previous copy
           name: artifacts-dist-manifest
@@ -220,43 +214,26 @@ jobs:
       "id-token": "write"
       "packages": "write"
 
-  custom-publish-wasm:
-    needs:
-      - plan
-      - host
-    if: ${{ !fromJson(needs.plan.outputs.val).announcement_is_prerelease || fromJson(needs.plan.outputs.val).publish_prereleases }}
-    uses: ./.github/workflows/publish-wasm.yml
-    with:
-      plan: ${{ needs.plan.outputs.val }}
-    secrets: inherit
-    # publish jobs get escalated permissions
-    permissions:
-      "contents": "read"
-      "id-token": "write"
-      "packages": "write"
-
   # Create a GitHub Release while uploading all files to it
   announce:
     needs:
       - plan
       - host
       - custom-publish-pypi
-      - custom-publish-wasm
     # use "always() && ..." to allow us to wait for all publish jobs while
     # still allowing individual publish jobs to skip themselves (for prereleases).
     # "host" however must run to completion, no skipping allowed!
-    if: ${{ always() && needs.host.result == 'success' && (needs.custom-publish-pypi.result == 'skipped' || needs.custom-publish-pypi.result == 'success') && (needs.custom-publish-wasm.result == 'skipped' || needs.custom-publish-wasm.result == 'success') }}
-    runs-on: "depot-ubuntu-latest-4"
+    if: ${{ always() && needs.host.result == 'success' && (needs.custom-publish-pypi.result == 'skipped' || needs.custom-publish-pypi.result == 'success') }}
+    runs-on: "ubuntu-20.04"
     env:
       GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
     steps:
-      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683
+      - uses: actions/checkout@v4
         with:
-          persist-credentials: false
           submodules: recursive
       # Create a GitHub Release while uploading all files to it
       - name: "Download GitHub Artifacts"
-        uses: actions/download-artifact@95815c38cf2ff2164869cbab79da8d1f422bc89e
+        uses: actions/download-artifact@v4
         with:
           pattern: artifacts-*
           path: artifacts

.github/workflows/sync_typeshed.yaml

@@ -21,17 +21,15 @@ jobs:
       contents: write
       pull-requests: write
     steps:
-      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+      - uses: actions/checkout@v4
         name: Checkout Ruff
         with:
           path: ruff
-          persist-credentials: true
-      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+      - uses: actions/checkout@v4
         name: Checkout typeshed
         with:
           repository: python/typeshed
           path: typeshed
-          persist-credentials: false
       - name: Setup git
         run: |
           git config --global user.name typeshedbot
@@ -39,13 +37,13 @@ jobs:
       - name: Sync typeshed
         id: sync
         run: |
-          rm -rf ruff/crates/red_knot_vendored/vendor/typeshed
-          mkdir ruff/crates/red_knot_vendored/vendor/typeshed
-          cp typeshed/README.md ruff/crates/red_knot_vendored/vendor/typeshed
-          cp typeshed/LICENSE ruff/crates/red_knot_vendored/vendor/typeshed
-          cp -r typeshed/stdlib ruff/crates/red_knot_vendored/vendor/typeshed/stdlib
-          rm -rf ruff/crates/red_knot_vendored/vendor/typeshed/stdlib/@tests
-          git -C typeshed rev-parse HEAD > ruff/crates/red_knot_vendored/vendor/typeshed/source_commit.txt
+          rm -rf ruff/crates/red_knot_module_resolver/vendor/typeshed
+          mkdir ruff/crates/red_knot_module_resolver/vendor/typeshed
+          cp typeshed/README.md ruff/crates/red_knot_module_resolver/vendor/typeshed
+          cp typeshed/LICENSE ruff/crates/red_knot_module_resolver/vendor/typeshed
+          cp -r typeshed/stdlib ruff/crates/red_knot_module_resolver/vendor/typeshed/stdlib
+          rm -rf ruff/crates/red_knot_module_resolver/vendor/typeshed/stdlib/@tests
+          git -C typeshed rev-parse HEAD > ruff/crates/red_knot_module_resolver/vendor/typeshed/source_commit.txt
       - name: Commit the changes
         id: commit
         if: ${{ steps.sync.outcome == 'success' }}
@@ -59,7 +57,7 @@ jobs:
         run: |
           cd ruff
           git push --force origin typeshedbot/sync-typeshed
-          gh pr list --repo "$GITHUB_REPOSITORY" --head typeshedbot/sync-typeshed --json id --jq length | grep 1 && exit 0 # exit if there is existing pr
+          gh pr list --repo $GITHUB_REPOSITORY --head typeshedbot/sync-typeshed --json id --jq length | grep 1 && exit 0 # exit if there is existing pr
           gh pr create --title "Sync vendored typeshed stubs" --body "Close and reopen this PR to trigger CI" --label "internal"
 
   create-issue-on-failure:
@@ -70,7 +68,7 @@ jobs:
     permissions:
       issues: write
     steps:
-      - uses: actions/github-script@60a0d83039c74a4aee543508d2ffcb1c3799cdea # v7.0.1
+      - uses: actions/github-script@v7
         with:
           github-token: ${{ secrets.GITHUB_TOKEN }}
           script: |
@@ -78,6 +76,5 @@ jobs:
               owner: "astral-sh",
               repo: "ruff",
               title: `Automated typeshed sync failed on ${new Date().toDateString()}`,
-              body: "Run listed here: https://github.com/${{ github.repository }}/actions/runs/${{ github.run_id }}",
-              labels: ["bug", "red-knot"],
+              body: "Runs are listed here: https://github.com/astral-sh/ruff/actions/workflows/sync_typeshed.yaml",
             })

.github/zizmor.yml

@@ -1,19 +0,0 @@
-# Configuration for the zizmor static analysis tool, run via pre-commit in CI
-# https://woodruffw.github.io/zizmor/configuration/
-#
-# TODO: can we remove the ignores here so that our workflows are more secure?
-rules:
-  dangerous-triggers:
-    ignore:
-      - pr-comment.yaml
-  cache-poisoning:
-    ignore:
-      - build-docker.yml
-      - publish-playground.yml
-  excessive-permissions:
-    # it's hard to test what the impact of removing these ignores would be
-    # without actually running the release workflow...
-    ignore:
-      - build-docker.yml
-      - publish-playground.yml
-      - publish-docs.yml

.gitignore

@@ -21,18 +21,6 @@ flamegraph.svg
 # `CARGO_TARGET_DIR=target-llvm-lines RUSTFLAGS="-Csymbol-mangling-version=v0" cargo llvm-lines -p ruff --lib`
 /target*
 
-# samply profiles
-profile.json
-
-# tracing-flame traces
-tracing.folded
-tracing-flamechart.svg
-tracing-flamegraph.svg
-
-# insta
-*.rs.pending-snap
-
-
 ###
 # Rust.gitignore
 ###

.ignore

@@ -1 +0,0 @@
-!/.github/

.markdownlint.yaml

@@ -14,18 +14,7 @@ MD041: false
 # MD013/line-length
 MD013: false
 
-# MD014/commands-show-output
-MD014: false
-
 # MD024/no-duplicate-heading
 MD024:
   # Allow when nested under different parents e.g. CHANGELOG.md
   siblings_only: true
-
-# MD046/code-block-style
-#
-# Ignore this because it conflicts with the code block style used in content
-# tabs of mkdocs-material which is to add a blank line after the content title.
-#
-# Ref: https://github.com/astral-sh/ruff/pull/15011#issuecomment-2544790854
-MD046: false

.pre-commit-config.yaml

@@ -1,15 +1,10 @@
-fail_fast: false
+fail_fast: true
 
 exclude: |
   (?x)^(
-    .github/workflows/release.yml|
-    crates/red_knot_vendored/vendor/.*|
-    crates/red_knot_project/resources/.*|
-    crates/ruff_benchmark/resources/.*|
+    crates/red_knot_module_resolver/vendor/.*|
     crates/ruff_linter/resources/.*|
     crates/ruff_linter/src/rules/.*/snapshots/.*|
-    crates/ruff_notebook/resources/.*|
-    crates/ruff_server/resources/.*|
     crates/ruff/resources/.*|
     crates/ruff_python_formatter/resources/.*|
     crates/ruff_python_formatter/tests/snapshots/.*|
@@ -18,23 +13,18 @@ exclude: |
   )$
 
 repos:
-  - repo: https://github.com/pre-commit/pre-commit-hooks
-    rev: v5.0.0
-    hooks:
-      - id: check-merge-conflict
-
   - repo: https://github.com/abravalheri/validate-pyproject
-    rev: v0.24.1
+    rev: v0.18
     hooks:
       - id: validate-pyproject
 
   - repo: https://github.com/executablebooks/mdformat
-    rev: 0.7.22
+    rev: 0.7.17
     hooks:
       - id: mdformat
         additional_dependencies:
-          - mdformat-mkdocs==4.0.0
-          - mdformat-footnote==0.1.1
+          - mdformat-mkdocs
+          - mdformat-admon
         exclude: |
           (?x)^(
             docs/formatter/black\.md
@@ -42,7 +32,7 @@ repos:
           )$
 
   - repo: https://github.com/igorshubovych/markdownlint-cli
-    rev: v0.44.0
+    rev: v0.41.0
     hooks:
       - id: markdownlint-fix
         exclude: |
@@ -51,21 +41,8 @@ repos:
             | docs/\w+\.md
           )$
 
-  - repo: https://github.com/adamchainz/blacken-docs
-    rev: 1.19.1
-    hooks:
-      - id: blacken-docs
-        args: ["--pyi", "--line-length", "130"]
-        files: '^crates/.*/resources/mdtest/.*\.md'
-        exclude: |
-          (?x)^(
-            .*?invalid(_.+)*_syntax\.md
-          )$
-        additional_dependencies:
-          - black==25.1.0
-
   - repo: https://github.com/crate-ci/typos
-    rev: v1.31.1
+    rev: v1.23.1
     hooks:
       - id: typos
 
@@ -79,52 +56,25 @@ repos:
         pass_filenames: false # This makes it a lot faster
 
   - repo: https://github.com/astral-sh/ruff-pre-commit
-    rev: v0.11.5
+    rev: v0.5.1
     hooks:
       - id: ruff-format
       - id: ruff
         args: [--fix, --exit-non-zero-on-fix]
         types_or: [python, pyi]
         require_serial: true
+        exclude: |
+          (?x)^(
+            crates/ruff_linter/resources/.*|
+            crates/ruff_python_formatter/resources/.*
+          )$
 
   # Prettier
-  - repo: https://github.com/rbubley/mirrors-prettier
-    rev: v3.5.3
+  - repo: https://github.com/pre-commit/mirrors-prettier
+    rev: v3.1.0
     hooks:
       - id: prettier
         types: [yaml]
 
-  # zizmor detects security vulnerabilities in GitHub Actions workflows.
-  # Additional configuration for the tool is found in `.github/zizmor.yml`
-  - repo: https://github.com/woodruffw/zizmor-pre-commit
-    rev: v1.5.2
-    hooks:
-      - id: zizmor
-
-  - repo: https://github.com/python-jsonschema/check-jsonschema
-    rev: 0.33.0
-    hooks:
-      - id: check-github-workflows
-
-  # `actionlint` hook, for verifying correct syntax in GitHub Actions workflows.
-  # Some additional configuration for `actionlint` can be found in `.github/actionlint.yaml`.
-  - repo: https://github.com/rhysd/actionlint
-    rev: v1.7.7
-    hooks:
-      - id: actionlint
-        stages:
-          # This hook is disabled by default, since it's quite slow.
-          # To run all hooks *including* this hook, use `uvx pre-commit run -a --hook-stage=manual`.
-          # To run *just* this hook, use `uvx pre-commit run -a actionlint --hook-stage=manual`.
-          - manual
-        args:
-          - "-ignore=SC2129" # ignorable stylistic lint from shellcheck
-          - "-ignore=SC2016" # another shellcheck lint: seems to have false positives?
-        additional_dependencies:
-          # actionlint has a shellcheck integration which extracts shell scripts in `run:` steps from GitHub Actions
-          # and checks these with shellcheck. This is arguably its most useful feature,
-          # but the integration only works if shellcheck is installed
-          - "github.com/wasilibs/go-shellcheck/cmd/shellcheck@v0.10.0"
-
 ci:
   skip: [cargo-fmt, dev-generate-all]

BREAKING_CHANGES.md

@@ -1,135 +1,5 @@
 # Breaking Changes
 
-## 0.11.0
-
-This is a follow-up to release 0.10.0. Because of a mistake in the release process, the `requires-python` inference changes were not included in that release. Ruff 0.11.0 now includes this change as well as the stabilization of the preview behavior for `PGH004`.
-
-- **Changes to how the Python version is inferred when a `target-version` is not specified** ([#16319](https://github.com/astral-sh/ruff/pull/16319))
-
-    In previous versions of Ruff, you could specify your Python version with:
-
-    - The `target-version` option in a `ruff.toml` file or the `[tool.ruff]` section of a pyproject.toml file.
-    - The `project.requires-python` field in a `pyproject.toml` file with a `[tool.ruff]` section.
-
-    These options worked well in most cases, and are still recommended for fine control of the Python version. However, because of the way Ruff discovers config files, `pyproject.toml` files without a `[tool.ruff]` section would be ignored, including the `requires-python` setting. Ruff would then use the default Python version (3.9 as of this writing) instead, which is surprising when you've attempted to request another version.
-
-    In v0.10, config discovery has been updated to address this issue:
-
-    - If Ruff finds a `ruff.toml` file without a `target-version`, it will check
-        for a `pyproject.toml` file in the same directory and respect its
-        `requires-python` version, even if it does not contain a `[tool.ruff]`
-        section.
-    - If Ruff finds a user-level configuration, the `requires-python` field of the closest `pyproject.toml` in a parent directory will take precedence.
-    - If there is no config file (`ruff.toml`or `pyproject.toml` with a
-        `[tool.ruff]` section) in the directory of the file being checked, Ruff will
-        search for the closest `pyproject.toml` in the parent directories and use its
-        `requires-python` setting.
-
-## 0.10.0
-
-- **Changes to how the Python version is inferred when a `target-version` is not specified** ([#16319](https://github.com/astral-sh/ruff/pull/16319))
-
-    Because of a mistake in the release process, the `requires-python` inference changes are not included in this release and instead shipped as part of 0.11.0.
-    You can find a description of this change in the 0.11.0 section.
-
-- **Updated `TYPE_CHECKING` behavior** ([#16669](https://github.com/astral-sh/ruff/pull/16669))
-
-    Previously, Ruff only recognized typechecking blocks that tested the `typing.TYPE_CHECKING` symbol. Now, Ruff recognizes any local variable named `TYPE_CHECKING`. This release also removes support for the legacy `if 0:` and `if False:` typechecking checks. Use a local `TYPE_CHECKING` variable instead.
-
-- **More robust noqa parsing** ([#16483](https://github.com/astral-sh/ruff/pull/16483))
-
-    The syntax for both file-level and in-line suppression comments has been unified and made more robust to certain errors. In most cases, this will result in more suppression comments being read by Ruff, but there are a few instances where previously read comments will now log an error to the user instead. Please refer to the documentation on [_Error suppression_](https://docs.astral.sh/ruff/linter/#error-suppression) for the full specification.
-
-- **Avoid unnecessary parentheses around with statements with a single context manager and a trailing comment** ([#14005](https://github.com/astral-sh/ruff/pull/14005))
-
-    This change fixes a bug in the formatter where it introduced unnecessary parentheses around with statements with a single context manager and a trailing comment. This change may result in a change in formatting for some users.
-
-- **Bump alpine default tag to 3.21 for derived Docker images** ([#16456](https://github.com/astral-sh/ruff/pull/16456))
-
-    Alpine 3.21 was released in Dec 2024 and is used in the official Alpine-based Python images. Now the ruff:alpine image will use 3.21 instead of 3.20 and ruff:alpine3.20 will no longer be updated.
-
-- **\[`unsafe-markup-use`\]: `RUF035` has been recoded to `S704`** ([#15957](https://github.com/astral-sh/ruff/pull/15957))
-
-## 0.9.0
-
-Ruff now formats your code according to the 2025 style guide. As a result, your code might now get formatted differently. See the [changelog](./CHANGELOG.md#090) for a detailed list of changes.
-
-## 0.8.0
-
-- **Default to Python 3.9**
-
-    Ruff now defaults to Python 3.9 instead of 3.8 if no explicit Python version is configured using [`ruff.target-version`](https://docs.astral.sh/ruff/settings/#target-version) or [`project.requires-python`](https://packaging.python.org/en/latest/guides/writing-pyproject-toml/#python-requires) ([#13896](https://github.com/astral-sh/ruff/pull/13896))
-
-- **Changed location of `pydoclint` diagnostics**
-
-    [`pydoclint`](https://docs.astral.sh/ruff/rules/#pydoclint-doc) diagnostics now point to the first-line of the problematic docstring. Previously, this was not the case.
-
-    If you've opted into these preview rules but have them suppressed using
-    [`noqa`](https://docs.astral.sh/ruff/linter/#error-suppression) comments in
-    some places, this change may mean that you need to move the `noqa` suppression
-    comments. Most users should be unaffected by this change.
-
-- **Use XDG (i.e. `~/.local/bin`) instead of the Cargo home directory in the standalone installer**
-
-    Previously, Ruff's installer used `$CARGO_HOME` or `~/.cargo/bin` for its target install directory. Now, Ruff will be installed into `$XDG_BIN_HOME`, `$XDG_DATA_HOME/../bin`, or `~/.local/bin` (in that order).
-
-    This change is only relevant to users of the standalone Ruff installer (using the shell or PowerShell script). If you installed Ruff using uv or pip, you should be unaffected.
-
-- **Changes to the line width calculation**
-
-    Ruff now uses a new version of the [unicode-width](https://github.com/unicode-rs/unicode-width) Rust crate to calculate the line width. In very rare cases, this may lead to lines containing Unicode characters being reformatted, or being considered too long when they were not before ([`E501`](https://docs.astral.sh/ruff/rules/line-too-long/)).
-
-## 0.7.0
-
-- The pytest rules `PT001` and `PT023` now default to omitting the decorator parentheses when there are no arguments
-    ([#12838](https://github.com/astral-sh/ruff/pull/12838), [#13292](https://github.com/astral-sh/ruff/pull/13292)).
-    This was a change that we attempted to make in Ruff v0.6.0, but only partially made due to an error on our part.
-    See the [blog post](https://astral.sh/blog/ruff-v0.7.0) for more details.
-- The `useless-try-except` rule (in our `tryceratops` category) has been recoded from `TRY302` to
-    `TRY203` ([#13502](https://github.com/astral-sh/ruff/pull/13502)). This ensures Ruff's code is consistent with
-    the same rule in the [`tryceratops`](https://github.com/guilatrova/tryceratops) linter.
-- The `lint.allow-unused-imports` setting has been removed ([#13677](https://github.com/astral-sh/ruff/pull/13677)). Use
-    [`lint.pyflakes.allow-unused-imports`](https://docs.astral.sh/ruff/settings/#lint_pyflakes_allowed-unused-imports)
-    instead.
-
-## 0.6.0
-
-- Detect imports in `src` layouts by default for `isort` rules ([#12848](https://github.com/astral-sh/ruff/pull/12848))
-
-- The pytest rules `PT001` and `PT023` now default to omitting the decorator parentheses when there are no arguments ([#12838](https://github.com/astral-sh/ruff/pull/12838)).
-
-- Lint and format Jupyter Notebook by default ([#12878](https://github.com/astral-sh/ruff/pull/12878)).
-
-    You can disable specific rules for notebooks using [`per-file-ignores`](https://docs.astral.sh/ruff/settings/#lint_per-file-ignores):
-
-    ```toml
-    [tool.ruff.lint.per-file-ignores]
-    "*.ipynb" = ["E501"] # disable line-too-long in notebooks
-    ```
-
-    If you'd prefer to either only lint or only format Jupyter Notebook files, you can use the
-    section-specific `exclude` option to do so. For example, the following would only lint Jupyter
-    Notebook files and not format them:
-
-    ```toml
-    [tool.ruff.format]
-    exclude = ["*.ipynb"]
-    ```
-
-    And, conversely, the following would only format Jupyter Notebook files and not lint them:
-
-    ```toml
-    [tool.ruff.lint]
-    exclude = ["*.ipynb"]
-    ```
-
-    You can completely disable Jupyter Notebook support by updating the [`extend-exclude`](https://docs.astral.sh/ruff/settings/#extend-exclude) setting:
-
-    ```toml
-    [tool.ruff]
-    extend-exclude = ["*.ipynb"]
-    ```
-
 ## 0.5.0
 
 - Follow the XDG specification to discover user-level configurations on macOS (same as on other Unix platforms)
@@ -246,7 +116,7 @@ flag or `unsafe-fixes` configuration option can be used to enable unsafe fixes.
 
 See the [docs](https://docs.astral.sh/ruff/configuration/#fix-safety) for details.
 
-### Remove formatter-conflicting rules from the default rule set ([#7900](https://github.com/astral-sh/ruff/pull/7900))
+### Remove formatter-conflicting rules from the default rule set  ([#7900](https://github.com/astral-sh/ruff/pull/7900))
 
 Previously, Ruff enabled all implemented rules in Pycodestyle (`E`) by default. Ruff now only includes the
 Pycodestyle prefixes `E4`, `E7`, and `E9` to exclude rules that conflict with automatic formatters. Consequently,
@@ -259,8 +129,8 @@ This change only affects those using Ruff under its default rule set. Users that
 
 ### Remove support for emoji identifiers ([#7212](https://github.com/astral-sh/ruff/pull/7212))
 
-Previously, Ruff supported non-standards-compliant emoji identifiers such as `📦 = 1`.
-We decided to remove this non-standard language extension. Ruff now reports syntax errors for invalid emoji identifiers in your code, the same as CPython.
+Previously, Ruff supported the non-standard compliant emoji identifiers e.g. `📦 = 1`.
+We decided to remove this non-standard language extension, and Ruff now reports syntax errors for emoji identifiers in your code, the same as CPython.
 
 ### Improved GitLab fingerprints ([#7203](https://github.com/astral-sh/ruff/pull/7203))
 

CONTRIBUTING.md

@@ -2,6 +2,35 @@
 
 Welcome! We're happy to have you here. Thank you in advance for your contribution to Ruff.
 
+- [The Basics](#the-basics)
+    - [Prerequisites](#prerequisites)
+    - [Development](#development)
+    - [Project Structure](#project-structure)
+    - [Example: Adding a new lint rule](#example-adding-a-new-lint-rule)
+        - [Rule naming convention](#rule-naming-convention)
+        - [Rule testing: fixtures and snapshots](#rule-testing-fixtures-and-snapshots)
+    - [Example: Adding a new configuration option](#example-adding-a-new-configuration-option)
+- [MkDocs](#mkdocs)
+- [Release Process](#release-process)
+    - [Creating a new release](#creating-a-new-release)
+- [Ecosystem CI](#ecosystem-ci)
+- [Benchmarking and Profiling](#benchmarking-and-profiling)
+    - [CPython Benchmark](#cpython-benchmark)
+    - [Microbenchmarks](#microbenchmarks)
+        - [Benchmark-driven Development](#benchmark-driven-development)
+        - [PR Summary](#pr-summary)
+        - [Tips](#tips)
+    - [Profiling Projects](#profiling-projects)
+        - [Linux](#linux)
+        - [Mac](#mac)
+- [`cargo dev`](#cargo-dev)
+- [Subsystems](#subsystems)
+    - [Compilation Pipeline](#compilation-pipeline)
+    - [Import Categorization](#import-categorization)
+        - [Project root](#project-root)
+        - [Package root](#package-root)
+        - [Import categorization](#import-categorization-1)
+
 ## The Basics
 
 Ruff welcomes contributions in the form of pull requests.
@@ -29,14 +58,16 @@ You'll also need [Insta](https://insta.rs/docs/) to update snapshot tests:
 cargo install cargo-insta
 ```
 
-You'll need [uv](https://docs.astral.sh/uv/getting-started/installation/) (or `pipx` and `pip`) to
-run Python utility commands.
+And you'll need pre-commit to run some validation checks:
+
+```shell
+pipx install pre-commit  # or `pip install pre-commit` if you have a virtualenv
+```
 
 You can optionally install pre-commit hooks to automatically run the validation checks
 when making a commit:
 
 ```shell
-uv tool install pre-commit
 pre-commit install
 ```
 
@@ -64,7 +95,7 @@ and that it passes both the lint and test validation checks:
 ```shell
 cargo clippy --workspace --all-targets --all-features -- -D warnings  # Rust linting
 RUFF_UPDATE_SCHEMA=1 cargo test  # Rust testing and updating ruff.schema.json
-uvx pre-commit run --all-files --show-diff-on-failure  # Rust and Python formatting, Markdown and Python linting, etc.
+pre-commit run --all-files --show-diff-on-failure  # Rust and Python formatting, Markdown and Python linting, etc.
 ```
 
 These checks will run on GitHub Actions when you open your pull request, but running them locally
@@ -139,7 +170,7 @@ At a high level, the steps involved in adding a new lint rule are as follows:
 1. Create a file for your rule (e.g., `crates/ruff_linter/src/rules/flake8_bugbear/rules/assert_false.rs`).
 
 1. In that file, define a violation struct (e.g., `pub struct AssertFalse`). You can grep for
-    `#[derive(ViolationMetadata)]` to see examples.
+    `#[violation]` to see examples.
 
 1. In that file, define a function that adds the violation to the diagnostic list as appropriate
     (e.g., `pub(crate) fn assert_false`) based on whatever inputs are required for the rule (e.g.,
@@ -265,20 +296,26 @@ To preview any changes to the documentation locally:
 
 1. Install the [Rust toolchain](https://www.rust-lang.org/tools/install).
 
+1. Install MkDocs and Material for MkDocs with:
+
+    ```shell
+    pip install -r docs/requirements.txt
+    ```
+
 1. Generate the MkDocs site with:
 
     ```shell
-    uv run --no-project --isolated --with-requirements docs/requirements.txt scripts/generate_mkdocs.py
+    python scripts/generate_mkdocs.py
     ```
 
 1. Run the development server with:
 
     ```shell
     # For contributors.
-    uvx --with-requirements docs/requirements.txt -- mkdocs serve -f mkdocs.public.yml
+    mkdocs serve -f mkdocs.public.yml
 
     # For members of the Astral org, which has access to MkDocs Insiders via sponsorship.
-    uvx --with-requirements docs/requirements-insiders.txt -- mkdocs serve -f mkdocs.insiders.yml
+    mkdocs serve -f mkdocs.insiders.yml
     ```
 
 The documentation should then be available locally at
@@ -296,34 +333,22 @@ even patch releases may contain [non-backwards-compatible changes](https://semve
 ### Creating a new release
 
 1. Install `uv`: `curl -LsSf https://astral.sh/uv/install.sh | sh`
-
 1. Run `./scripts/release.sh`; this command will:
-
     - Generate a temporary virtual environment with `rooster`
     - Generate a changelog entry in `CHANGELOG.md`
     - Update versions in `pyproject.toml` and `Cargo.toml`
     - Update references to versions in the `README.md` and documentation
     - Display contributors for the release
-
 1. The changelog should then be editorialized for consistency
-
     - Often labels will be missing from pull requests they will need to be manually organized into the proper section
     - Changes should be edited to be user-facing descriptions, avoiding internal details
-
 1. Highlight any breaking changes in `BREAKING_CHANGES.md`
-
 1. Run `cargo check`. This should update the lock file with new versions.
-
 1. Create a pull request with the changelog and version updates
-
 1. Merge the PR
-
 1. Run the [release workflow](https://github.com/astral-sh/ruff/actions/workflows/release.yml) with:
-
     - The new version number (without starting `v`)
-
 1. The release workflow will do the following:
-
     1. Build all the assets. If this fails (even though we tested in step 4), we haven't tagged or
         uploaded anything, you can restart after pushing a fix. If you just need to rerun the build,
         make sure you're [re-running all the failed
@@ -334,25 +359,14 @@ even patch releases may contain [non-backwards-compatible changes](https://semve
     1. Attach artifacts to draft GitHub release
     1. Trigger downstream repositories. This can fail non-catastrophically, as we can run any
         downstream jobs manually if needed.
-
 1. Verify the GitHub release:
-
     1. The Changelog should match the content of `CHANGELOG.md`
-    1. Append the contributors from the `scripts/release.sh` script
-
+    1. Append the contributors from the `bump.sh` script
 1. If needed, [update the schemastore](https://github.com/astral-sh/ruff/blob/main/scripts/update_schemastore.py).
-
     1. One can determine if an update is needed when
         `git diff old-version-tag new-version-tag -- ruff.schema.json` returns a non-empty diff.
     1. Once run successfully, you should follow the link in the output to create a PR.
-
-1. If needed, update the [`ruff-lsp`](https://github.com/astral-sh/ruff-lsp) and
-    [`ruff-vscode`](https://github.com/astral-sh/ruff-vscode) repositories and follow
-    the release instructions in those repositories. `ruff-lsp` should always be updated
-    before `ruff-vscode`.
-
-    This step is generally not required for a patch release, but should always be done
-    for a minor release.
+1. If needed, update the `ruff-lsp` and `ruff-vscode` repositories.
 
 ## Ecosystem CI
 
@@ -360,8 +374,9 @@ GitHub Actions will run your changes against a number of real-world projects fro
 report on any linter or formatter differences. You can also run those checks locally via:
 
 ```shell
-uvx --from ./python/ruff-ecosystem ruff-ecosystem check ruff "./target/debug/ruff"
-uvx --from ./python/ruff-ecosystem ruff-ecosystem format ruff "./target/debug/ruff"
+pip install -e ./python/ruff-ecosystem
+ruff-ecosystem check ruff "./target/debug/ruff"
+ruff-ecosystem format ruff "./target/debug/ruff"
 ```
 
 See the [ruff-ecosystem package](https://github.com/astral-sh/ruff/tree/main/python/ruff-ecosystem) for more details.
@@ -374,7 +389,7 @@ We have several ways of benchmarking and profiling Ruff:
 - Microbenchmarks which run the linter or the formatter on individual files. These run on pull requests.
 - Profiling the linter on either the microbenchmarks or entire projects
 
-> **Note**
+> \[!NOTE\]
 > When running benchmarks, ensure that your CPU is otherwise idle (e.g., close any background
 > applications, like web browsers). You may also want to switch your CPU to a "performance"
 > mode, if it exists, especially when benchmarking short-lived processes.
@@ -388,18 +403,12 @@ which makes it a good target for benchmarking.
 git clone --branch 3.10 https://github.com/python/cpython.git crates/ruff_linter/resources/test/cpython
 ```
 
-Install `hyperfine`:
-
-```shell
-cargo install hyperfine
-```
-
 To benchmark the release build:
 
 ```shell
 cargo build --release && hyperfine --warmup 10 \
-  "./target/release/ruff check ./crates/ruff_linter/resources/test/cpython/ --no-cache -e" \
-  "./target/release/ruff check ./crates/ruff_linter/resources/test/cpython/ -e"
+  "./target/release/ruff ./crates/ruff_linter/resources/test/cpython/ --no-cache -e" \
+  "./target/release/ruff ./crates/ruff_linter/resources/test/cpython/ -e"
 
 Benchmark 1: ./target/release/ruff ./crates/ruff_linter/resources/test/cpython/ --no-cache
   Time (mean ± σ):     293.8 ms ±   3.2 ms    [User: 2384.6 ms, System: 90.3 ms]
@@ -418,7 +427,7 @@ To benchmark against the ecosystem's existing tools:
 
 ```shell
 hyperfine --ignore-failure --warmup 5 \
-  "./target/release/ruff check ./crates/ruff_linter/resources/test/cpython/ --no-cache" \
+  "./target/release/ruff ./crates/ruff_linter/resources/test/cpython/ --no-cache" \
   "pyflakes crates/ruff_linter/resources/test/cpython" \
   "autoflake --recursive --expand-star-imports --remove-all-unused-imports --remove-unused-variables --remove-duplicate-keys resources/test/cpython" \
   "pycodestyle crates/ruff_linter/resources/test/cpython" \
@@ -464,10 +473,10 @@ To benchmark a subset of rules, e.g. `LineTooLong` and `DocLineTooLong`:
 
 ```shell
 cargo build --release && hyperfine --warmup 10 \
-  "./target/release/ruff check ./crates/ruff_linter/resources/test/cpython/ --no-cache -e --select W505,E501"
+  "./target/release/ruff ./crates/ruff_linter/resources/test/cpython/ --no-cache -e --select W505,E501"
 ```
 
-You can run `uv venv --project ./scripts/benchmarks`, activate the venv and then run `uv sync --project ./scripts/benchmarks` to create a working environment for the
+You can run `poetry install` from `./scripts/benchmarks` to create a working environment for the
 above. All reported benchmarks were computed using the versions specified by
 `./scripts/benchmarks/pyproject.toml` on Python 3.11.
 
@@ -521,12 +530,10 @@ You can run the benchmarks with
 cargo benchmark
 ```
 
-`cargo benchmark` is an alias for `cargo bench -p ruff_benchmark --bench linter --bench formatter --`
-
 #### Benchmark-driven Development
 
 Ruff uses [Criterion.rs](https://bheisler.github.io/criterion.rs/book/) for benchmarks. You can use
-`--save-baseline=<name>` to store an initial baseline benchmark (e.g., on `main`) and then use
+`--save-baseline=<name>` to store an initial baseline benchmark (e.g. on `main`) and then use
 `--benchmark=<name>` to compare against that benchmark. Criterion will print a message telling you
 if the benchmark improved/regressed compared to that baseline.
 
@@ -561,7 +568,7 @@ cargo install critcmp
 
 #### Tips
 
-- Use `cargo bench -p ruff_benchmark <filter>` to only run specific benchmarks. For example: `cargo bench -p ruff_benchmark lexer`
+- Use `cargo bench -p ruff_benchmark <filter>` to only run specific benchmarks. For example: `cargo benchmark lexer`
     to only run the lexer benchmarks.
 - Use `cargo bench -p ruff_benchmark -- --quiet` for a more cleaned up output (without statistical relevance)
 - Use `cargo bench -p ruff_benchmark -- --quick` to get faster results (more prone to noise)
@@ -678,9 +685,9 @@ utils with it:
 23 Newline 24
 ```
 
-- `cargo dev print-cst <file>`: Print the CST of a Python file using
+- `cargo dev print-cst <file>`: Print the CST of a python file using
     [LibCST](https://github.com/Instagram/LibCST), which is used in addition to the RustPython parser
-    in Ruff. For example, for `if True: pass # comment`, everything, including the whitespace, is represented:
+    in Ruff. E.g. for `if True: pass # comment` everything including the whitespace is represented:
 
 ```text
 Module {
@@ -863,7 +870,7 @@ each configuration file.
 
 The package root is used to determine a file's "module path". Consider, again, `baz.py`. In that
 case, `./my_project/src/foo` was identified as the package root, so the module path for `baz.py`
-would resolve to `foo.bar.baz` — as computed by taking the relative path from the package root
+would resolve to  `foo.bar.baz` — as computed by taking the relative path from the package root
 (inclusive of the root itself). The module path can be thought of as "the path you would use to
 import the module" (e.g., `import foo.bar.baz`).
 
@@ -898,11 +905,15 @@ There are three ways in which an import can be categorized as "first-party":
     package (e.g., `from foo import bar` or `import foo.bar`), they'll be classified as first-party
     automatically. This check is as simple as comparing the first segment of the current file's
     module path to the first segment of the import.
-1. **Source roots**: Ruff supports a [`src`](https://docs.astral.sh/ruff/settings/#src) setting, which
+1. **Source roots**: Ruff supports a `[src](https://docs.astral.sh/ruff/settings/#src)` setting, which
     sets the directories to scan when identifying first-party imports. The algorithm is
     straightforward: given an import, like `import foo`, iterate over the directories enumerated in
     the `src` setting and, for each directory, check for the existence of a subdirectory `foo` or a
     file `foo.py`.
 
-By default, `src` is set to the project root, along with `"src"` subdirectory in the project root.
-This ensures that Ruff supports both flat and "src" layouts out of the box.
+By default, `src` is set to the project root. In the above example, we'd want to set
+`src = ["./src"]` to ensure that we locate `./my_project/src/foo` and thus categorize `import foo`
+as first-party in `baz.py`. In practice, for this limited example, setting `src = ["./src"]` is
+unnecessary, as all imports within `./my_project/src/foo` would be categorized as first-party via
+the same-package heuristic; but if your project contains multiple packages, you'll want to set `src`
+explicitly.

Cargo.toml

@@ -4,7 +4,7 @@ resolver = "2"
 
 [workspace.package]
 edition = "2021"
-rust-version = "1.84"
+rust-version = "1.75"
 homepage = "https://docs.astral.sh/ruff"
 documentation = "https://docs.astral.sh/ruff"
 repository = "https://github.com/astral-sh/ruff"
@@ -13,12 +13,10 @@ license = "MIT"
 
 [workspace.dependencies]
 ruff = { path = "crates/ruff" }
-ruff_annotate_snippets = { path = "crates/ruff_annotate_snippets" }
 ruff_cache = { path = "crates/ruff_cache" }
-ruff_db = { path = "crates/ruff_db", default-features = false }
+ruff_db = { path = "crates/ruff_db" }
 ruff_diagnostics = { path = "crates/ruff_diagnostics" }
 ruff_formatter = { path = "crates/ruff_formatter" }
-ruff_graph = { path = "crates/ruff_graph" }
 ruff_index = { path = "crates/ruff_index" }
 ruff_linter = { path = "crates/ruff_linter" }
 ruff_macros = { path = "crates/ruff_macros" }
@@ -35,20 +33,15 @@ ruff_python_trivia = { path = "crates/ruff_python_trivia" }
 ruff_server = { path = "crates/ruff_server" }
 ruff_source_file = { path = "crates/ruff_source_file" }
 ruff_text_size = { path = "crates/ruff_text_size" }
-red_knot_vendored = { path = "crates/red_knot_vendored" }
 ruff_workspace = { path = "crates/ruff_workspace" }
 
-red_knot_ide = { path = "crates/red_knot_ide" }
-red_knot_project = { path = "crates/red_knot_project", default-features = false }
+red_knot = { path = "crates/red_knot" }
+red_knot_module_resolver = { path = "crates/red_knot_module_resolver" }
 red_knot_python_semantic = { path = "crates/red_knot_python_semantic" }
-red_knot_server = { path = "crates/red_knot_server" }
-red_knot_test = { path = "crates/red_knot_test" }
 
 aho-corasick = { version = "1.1.3" }
-anstream = { version = "0.6.18" }
-anstyle = { version = "1.0.10" }
+annotate-snippets = { version = "0.9.2", features = ["color"] }
 anyhow = { version = "1.0.80" }
-assert_fs = { version = "1.1.0" }
 argfile = { version = "0.2.0" }
 bincode = { version = "1.3.3" }
 bitflags = { version = "2.5.0" }
@@ -57,44 +50,35 @@ cachedir = { version = "0.3.1" }
 camino = { version = "1.1.7" }
 chrono = { version = "0.4.35", default-features = false, features = ["clock"] }
 clap = { version = "4.5.3", features = ["derive"] }
-clap_complete_command = { version = "0.6.0" }
-clearscreen = { version = "4.0.0" }
+clap_complete_command = { version = "0.5.1" }
+clearscreen = { version = "3.0.0" }
 codspeed-criterion-compat = { version = "2.6.0", default-features = false }
-colored = { version = "3.0.0" }
+colored = { version = "2.1.0" }
 console_error_panic_hook = { version = "0.1.7" }
 console_log = { version = "1.0.0" }
 countme = { version = "3.0.1" }
-compact_str = "0.9.0"
+compact_str = "0.7.1"
 criterion = { version = "0.5.1", default-features = false }
 crossbeam = { version = "0.8.4" }
 dashmap = { version = "6.0.1" }
-dir-test = { version = "0.4.0" }
-dunce = { version = "1.0.5" }
 drop_bomb = { version = "0.1.5" }
 env_logger = { version = "0.11.0" }
-etcetera = { version = "0.10.0" }
-fern = { version = "0.7.0" }
+etcetera = { version = "0.8.0" }
+fern = { version = "0.6.1" }
 filetime = { version = "0.2.23" }
-getrandom = { version = "0.3.1" }
 glob = { version = "0.3.1" }
 globset = { version = "0.4.14" }
-globwalk = { version = "0.9.1" }
-hashbrown = { version = "0.15.0", default-features = false, features = [
-    "raw-entry",
-    "equivalent",
-    "inline-more",
-] }
+hashbrown = "0.14.3"
 ignore = { version = "0.4.22" }
 imara-diff = { version = "0.1.5" }
 imperative = { version = "1.0.4" }
-indexmap = { version = "2.6.0" }
 indicatif = { version = "0.17.8" }
 indoc = { version = "2.0.4" }
 insta = { version = "1.35.1" }
 insta-cmd = { version = "0.6.0" }
 is-macro = { version = "0.3.5" }
 is-wsl = { version = "0.4.0" }
-itertools = { version = "0.14.0" }
+itertools = { version = "0.13.0" }
 js-sys = { version = "0.3.69" }
 jod-thread = { version = "0.1.2" }
 libc = { version = "0.2.153" }
@@ -102,29 +86,29 @@ libcst = { version = "1.1.0", default-features = false }
 log = { version = "0.4.17" }
 lsp-server = { version = "0.7.6" }
 lsp-types = { git = "https://github.com/astral-sh/lsp-types.git", rev = "3512a9f", features = [
-    "proposed",
+  "proposed",
 ] }
 matchit = { version = "0.8.1" }
 memchr = { version = "2.7.1" }
 mimalloc = { version = "0.1.39" }
 natord = { version = "1.0.9" }
-notify = { version = "8.0.0" }
+notify = { version = "6.1.1" }
+once_cell = { version = "1.19.0" }
 ordermap = { version = "0.5.0" }
 path-absolutize = { version = "3.1.1" }
 path-slash = { version = "0.2.1" }
 pathdiff = { version = "0.2.1" }
-pep440_rs = { version = "0.7.1" }
+pep440_rs = { version = "0.6.0", features = ["serde"] }
 pretty_assertions = "1.3.0"
 proc-macro2 = { version = "1.0.79" }
-pyproject-toml = { version = "0.13.4" }
-quick-junit = { version = "0.5.0" }
+pyproject-toml = { version = "0.9.0" }
+quick-junit = { version = "0.4.0" }
 quote = { version = "1.0.23" }
-rand = { version = "0.9.0" }
+rand = { version = "0.8.5" }
 rayon = { version = "1.10.0" }
 regex = { version = "1.10.2" }
 rustc-hash = { version = "2.0.0" }
-# When updating salsa, make sure to also update the revision in `fuzz/Cargo.toml`
-salsa = { git = "https://github.com/salsa-rs/salsa.git", rev = "87bf6b6c2d5f6479741271da73bd9d30c2580c26" }
+salsa = { git = "https://github.com/salsa-rs/salsa.git", rev = "a1bf3a613f451af7fc0a59411c56abc47fe8e8e1" }
 schemars = { version = "0.8.16" }
 seahash = { version = "4.1.0" }
 serde = { version = "1.0.197", features = ["derive"] }
@@ -132,66 +116,47 @@ serde-wasm-bindgen = { version = "0.6.4" }
 serde_json = { version = "1.0.113" }
 serde_test = { version = "1.0.152" }
 serde_with = { version = "3.6.0", default-features = false, features = [
-    "macros",
+  "macros",
 ] }
 shellexpand = { version = "3.0.0" }
 similar = { version = "2.4.0", features = ["inline"] }
 smallvec = { version = "1.13.2" }
-snapbox = { version = "0.6.0", features = [
-    "diff",
-    "term-svg",
-    "cmd",
-    "examples",
-] }
 static_assertions = "1.1.0"
-strum = { version = "0.27.0", features = ["strum_macros"] }
-strum_macros = { version = "0.27.0" }
+strum = { version = "0.26.0", features = ["strum_macros"] }
+strum_macros = { version = "0.26.0" }
 syn = { version = "2.0.55" }
 tempfile = { version = "3.9.0" }
 test-case = { version = "3.3.1" }
-thiserror = { version = "2.0.0" }
-tikv-jemallocator = { version = "0.6.0" }
+thiserror = { version = "1.0.58" }
+tikv-jemallocator = { version = "0.5.0" }
 toml = { version = "0.8.11" }
 tracing = { version = "0.1.40" }
-tracing-flame = { version = "0.2.0" }
 tracing-indicatif = { version = "0.3.6" }
-tracing-log = { version = "0.2.0" }
-tracing-subscriber = { version = "0.3.18", default-features = false, features = [
-    "env-filter",
-    "fmt",
-] }
-tracing-tree = { version = "0.4.0" }
-tryfn = { version = "0.2.1" }
+tracing-subscriber = { version = "0.3.18", features = ["env-filter"] }
+tracing-tree = { version = "0.3.0" }
 typed-arena = { version = "2.0.2" }
 unic-ucd-category = { version = "0.9" }
 unicode-ident = { version = "1.0.12" }
-unicode-width = { version = "0.2.0" }
+unicode-width = { version = "0.1.11" }
 unicode_names2 = { version = "1.2.2" }
 unicode-normalization = { version = "0.1.23" }
+ureq = { version = "2.9.6" }
 url = { version = "2.5.0" }
 uuid = { version = "1.6.1", features = [
-    "v4",
-    "fast-rng",
-    "macro-diagnostics",
-    "js",
+  "v4",
+  "fast-rng",
+  "macro-diagnostics",
+  "js",
 ] }
 walkdir = { version = "2.3.2" }
 wasm-bindgen = { version = "0.2.92" }
 wasm-bindgen-test = { version = "0.3.42" }
 wild = { version = "2" }
-zip = { version = "0.6.6", default-features = false }
-
-[workspace.metadata.cargo-shear]
-ignored = ["getrandom"]
-
+zip = { version = "0.6.6", default-features = false, features = ["zstd"] }
 
 [workspace.lints.rust]
 unsafe_code = "warn"
 unreachable_pub = "warn"
-unexpected_cfgs = { level = "warn", check-cfg = [
-    "cfg(fuzzing)",
-    "cfg(codspeed)",
-] }
 
 [workspace.lints.clippy]
 pedantic = { level = "warn", priority = -2 }
@@ -207,10 +172,8 @@ missing_panics_doc = "allow"
 module_name_repetitions = "allow"
 must_use_candidate = "allow"
 similar_names = "allow"
-single_match_else = "allow"
 too_many_lines = "allow"
-needless_continue = "allow"       # An explicit continue can be more readable, especially if the alternative is an empty block.
-# Without the hashes we run into a `rustfmt` bug in some snapshot tests, see #13250
+# To allow `#[allow(clippy::all)]` in `crates/ruff_python_parser/src/python.rs`.
 needless_raw_string_hashes = "allow"
 # Disallowed restriction lints
 print_stdout = "warn"
@@ -223,13 +186,6 @@ get_unwrap = "warn"
 rc_buffer = "warn"
 rc_mutex = "warn"
 rest_pat_in_fully_bound_structs = "warn"
-# nursery rules
-redundant_clone = "warn"
-debug_assert_with_mut_call = "warn"
-unused_peekable = "warn"
-
-# Diagnostics are not actionable: Enable once https://github.com/rust-lang/rust-clippy/issues/13774 is resolved.
-large_stack_arrays = "allow"
 
 [profile.release]
 # Note that we set these explicitly, and these values
@@ -269,12 +225,12 @@ debug = 1
 [profile.dist]
 inherits = "release"
 
-# Config for 'dist'
+# Config for 'cargo dist'
 [workspace.metadata.dist]
-# The preferred dist version to use in CI (Cargo.toml SemVer syntax)
-cargo-dist-version = "0.28.4-prerelease.1"
+# The preferred cargo-dist version to use in CI (Cargo.toml SemVer syntax)
+cargo-dist-version = "0.18.0"
 # CI backends to support
-ci = "github"
+ci = ["github"]
 # The installers to generate for each app
 installers = ["shell", "powershell"]
 # The archive format to use for windows builds (defaults .zip)
@@ -283,58 +239,43 @@ windows-archive = ".zip"
 unix-archive = ".tar.gz"
 # Target platforms to build apps for (Rust target-triple syntax)
 targets = [
-    "aarch64-apple-darwin",
-    "aarch64-pc-windows-msvc",
-    "aarch64-unknown-linux-gnu",
-    "aarch64-unknown-linux-musl",
-    "arm-unknown-linux-musleabihf",
-    "armv7-unknown-linux-gnueabihf",
-    "armv7-unknown-linux-musleabihf",
-    "i686-pc-windows-msvc",
-    "i686-unknown-linux-gnu",
-    "i686-unknown-linux-musl",
-    "powerpc64-unknown-linux-gnu",
-    "powerpc64le-unknown-linux-gnu",
-    "s390x-unknown-linux-gnu",
-    "x86_64-apple-darwin",
-    "x86_64-pc-windows-msvc",
-    "x86_64-unknown-linux-gnu",
-    "x86_64-unknown-linux-musl",
+  "aarch64-apple-darwin",
+  "aarch64-pc-windows-msvc",
+  "aarch64-unknown-linux-gnu",
+  "aarch64-unknown-linux-musl",
+  "arm-unknown-linux-musleabihf",
+  "armv7-unknown-linux-gnueabihf",
+  "armv7-unknown-linux-musleabihf",
+  "i686-pc-windows-msvc",
+  "i686-unknown-linux-gnu",
+  "i686-unknown-linux-musl",
+  "powerpc64-unknown-linux-gnu",
+  "powerpc64le-unknown-linux-gnu",
+  "s390x-unknown-linux-gnu",
+  "x86_64-apple-darwin",
+  "x86_64-pc-windows-msvc",
+  "x86_64-unknown-linux-gnu",
+  "x86_64-unknown-linux-musl",
 ]
 # Whether to auto-include files like READMEs, LICENSEs, and CHANGELOGs (default true)
 auto-includes = false
-# Whether dist should create a Github Release or use an existing draft
+# Whether cargo-dist should create a GitHub Release or use an existing draft
 create-release = true
-# Which actions to run on pull requests
+# Publish jobs to run in CI
 pr-run-mode = "skip"
 # Whether CI should trigger releases with dispatches instead of tag pushes
 dispatch-releases = true
-# Which phase dist should use to create the GitHub release
+# The stage during which the GitHub Release should be created
 github-release = "announce"
 # Whether CI should include auto-generated code to build local artifacts
 build-local-artifacts = false
 # Local artifacts jobs to run in CI
 local-artifacts-jobs = ["./build-binaries", "./build-docker"]
 # Publish jobs to run in CI
-publish-jobs = ["./publish-pypi", "./publish-wasm"]
-# Post-announce jobs to run in CI
-post-announce-jobs = [
-    "./notify-dependents",
-    "./publish-docs",
-    "./publish-playground",
-]
+publish-jobs = ["./publish-pypi"]
+# Announcement jobs to run in CI
+post-announce-jobs = ["./notify-dependents", "./publish-docs", "./publish-playground"]
 # Custom permissions for GitHub Jobs
-github-custom-job-permissions = { "build-docker" = { packages = "write", contents = "read" }, "publish-wasm" = { contents = "read", id-token = "write", packages = "write" } }
+github-custom-job-permissions = { "build-docker" = { packages = "write", contents = "read" } }
 # Whether to install an updater program
 install-updater = false
-# Path that installers should place binaries in
-install-path = ["$XDG_BIN_HOME/", "$XDG_DATA_HOME/../bin", "~/.local/bin"]
-
-[workspace.metadata.dist.github-custom-runners]
-global = "depot-ubuntu-latest-4"
-
-[workspace.metadata.dist.github-action-commits]
-"actions/checkout" = "11bd71901bbe5b1630ceea73d27597364c9af683" # v4
-"actions/upload-artifact" = "ea165f8d65b6e75b540449e92b4886f43607fa02" # v4.6.2
-"actions/download-artifact" = "95815c38cf2ff2164869cbab79da8d1f422bc89e" # v4.2.1
-"actions/attest-build-provenance" = "c074443f1aee8d4aeeae555aebba3282517141b2" #v2.2.3

Dockerfile

@@ -1,4 +1,4 @@
-FROM --platform=$BUILDPLATFORM ubuntu AS build
+FROM --platform=$BUILDPLATFORM ubuntu as build
 ENV HOME="/root"
 WORKDIR $HOME
 

LICENSE

@@ -1371,28 +1371,3 @@ are:
     OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
     SOFTWARE.
   """
-
-- pydoclint, licensed as follows:
-  """
-    MIT License
-
-    Copyright (c) 2023 jsh9
-
-    Permission is hereby granted, free of charge, to any person obtaining a copy
-    of this software and associated documentation files (the "Software"), to deal
-    in the Software without restriction, including without limitation the rights
-    to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
-    copies of the Software, and to permit persons to whom the Software is
-    furnished to do so, subject to the following conditions:
-
-    The above copyright notice and this permission notice shall be included in all
-    copies or substantial portions of the Software.
-
-    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-    IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-    FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
-    AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-    LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
-    OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
-    SOFTWARE.
-  """

README.md

@@ -29,14 +29,14 @@ An extremely fast Python linter and code formatter, written in Rust.
 - 🐍 Installable via `pip`
 - 🛠️ `pyproject.toml` support
 - 🤝 Python 3.13 compatibility
-- ⚖️ Drop-in parity with [Flake8](https://docs.astral.sh/ruff/faq/#how-does-ruffs-linter-compare-to-flake8), isort, and [Black](https://docs.astral.sh/ruff/faq/#how-does-ruffs-formatter-compare-to-black)
+- ⚖️ Drop-in parity with [Flake8](https://docs.astral.sh/ruff/faq/#how-does-ruff-compare-to-flake8), isort, and Black
 - 📦 Built-in caching, to avoid re-analyzing unchanged files
 - 🔧 Fix support, for automatic error correction (e.g., automatically remove unused imports)
 - 📏 Over [800 built-in rules](https://docs.astral.sh/ruff/rules/), with native re-implementations
     of popular Flake8 plugins, like flake8-bugbear
 - ⌨️ First-party [editor integrations](https://docs.astral.sh/ruff/integrations/) for
-    [VS Code](https://github.com/astral-sh/ruff-vscode) and [more](https://docs.astral.sh/ruff/editors/setup)
-- 🌎 Monorepo-friendly, with [hierarchical and cascading configuration](https://docs.astral.sh/ruff/configuration/#config-file-discovery)
+    [VS Code](https://github.com/astral-sh/ruff-vscode) and [more](https://github.com/astral-sh/ruff-lsp)
+- 🌎 Monorepo-friendly, with [hierarchical and cascading configuration](https://docs.astral.sh/ruff/configuration/#pyprojecttoml-discovery)
 
 Ruff aims to be orders of magnitude faster than alternative tools while integrating more
 functionality behind a single, common interface.
@@ -110,28 +110,15 @@ For more, see the [documentation](https://docs.astral.sh/ruff/).
 1. [Who's Using Ruff?](#whos-using-ruff)
 1. [License](#license)
 
-## Getting Started<a id="getting-started"></a>
+## Getting Started
 
 For more, see the [documentation](https://docs.astral.sh/ruff/).
 
 ### Installation
 
-Ruff is available as [`ruff`](https://pypi.org/project/ruff/) on PyPI.
-
-Invoke Ruff directly with [`uvx`](https://docs.astral.sh/uv/):
+Ruff is available as [`ruff`](https://pypi.org/project/ruff/) on PyPI:
 
 ```shell
-uvx ruff check   # Lint all files in the current directory.
-uvx ruff format  # Format all files in the current directory.
-```
-
-Or install Ruff with `uv` (recommended), `pip`, or `pipx`:
-
-```shell
-# With uv.
-uv tool install ruff@latest  # Install Ruff globally.
-uv add --dev ruff            # Or add Ruff to your project.
-
 # With pip.
 pip install ruff
 
@@ -149,8 +136,8 @@ curl -LsSf https://astral.sh/ruff/install.sh | sh
 powershell -c "irm https://astral.sh/ruff/install.ps1 | iex"
 
 # For a specific version.
-curl -LsSf https://astral.sh/ruff/0.11.5/install.sh | sh
-powershell -c "irm https://astral.sh/ruff/0.11.5/install.ps1 | iex"
+curl -LsSf https://astral.sh/ruff/0.5.1/install.sh | sh
+powershell -c "irm https://astral.sh/ruff/0.5.1/install.ps1 | iex"
 ```
 
 You can also install Ruff via [Homebrew](https://formulae.brew.sh/formula/ruff), [Conda](https://anaconda.org/conda-forge/ruff),
@@ -183,7 +170,7 @@ Ruff can also be used as a [pre-commit](https://pre-commit.com/) hook via [`ruff
 ```yaml
 - repo: https://github.com/astral-sh/ruff-pre-commit
   # Ruff version.
-  rev: v0.11.5
+  rev: v0.5.1
   hooks:
     # Run the linter.
     - id: ruff
@@ -192,10 +179,11 @@ Ruff can also be used as a [pre-commit](https://pre-commit.com/) hook via [`ruff
     - id: ruff-format
 ```
 
-Ruff can also be used as a [VS Code extension](https://github.com/astral-sh/ruff-vscode) or with [various other editors](https://docs.astral.sh/ruff/editors/setup).
+Ruff can also be used as a [VS Code extension](https://github.com/astral-sh/ruff-vscode) or
+alongside any other editor through the [Ruff LSP](https://github.com/astral-sh/ruff-lsp).
 
 Ruff can also be used as a [GitHub Action](https://github.com/features/actions) via
-[`ruff-action`](https://github.com/astral-sh/ruff-action):
+[`ruff-action`](https://github.com/chartboost/ruff-action):
 
 ```yaml
 name: Ruff
@@ -205,10 +193,10 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4
-      - uses: astral-sh/ruff-action@v3
+      - uses: chartboost/ruff-action@v1
 ```
 
-### Configuration<a id="configuration"></a>
+### Configuration
 
 Ruff can be configured through a `pyproject.toml`, `ruff.toml`, or `.ruff.toml` file (see:
 [_Configuration_](https://docs.astral.sh/ruff/configuration/), or [_Settings_](https://docs.astral.sh/ruff/settings/)
@@ -251,8 +239,8 @@ exclude = [
 line-length = 88
 indent-width = 4
 
-# Assume Python 3.9
-target-version = "py39"
+# Assume Python 3.8
+target-version = "py38"
 
 [lint]
 # Enable Pyflakes (`F`) and a subset of the pycodestyle (`E`)  codes by default.
@@ -304,7 +292,7 @@ features that may change prior to stabilization.
 See `ruff help` for more on Ruff's top-level commands, or `ruff help check` and `ruff help format`
 for more on the linting and formatting commands, respectively.
 
-## Rules<a id="rules"></a>
+## Rules
 
 <!-- Begin section: Rules -->
 
@@ -380,21 +368,21 @@ quality tools, including:
 
 For a complete enumeration of the supported rules, see [_Rules_](https://docs.astral.sh/ruff/rules/).
 
-## Contributing<a id="contributing"></a>
+## Contributing
 
 Contributions are welcome and highly appreciated. To get started, check out the
 [**contributing guidelines**](https://docs.astral.sh/ruff/contributing/).
 
 You can also join us on [**Discord**](https://discord.com/invite/astral-sh).
 
-## Support<a id="support"></a>
+## Support
 
 Having trouble? Check out the existing issues on [**GitHub**](https://github.com/astral-sh/ruff/issues),
 or feel free to [**open a new one**](https://github.com/astral-sh/ruff/issues/new).
 
 You can also ask for help on [**Discord**](https://discord.com/invite/astral-sh).
 
-## Acknowledgements<a id="acknowledgements"></a>
+## Acknowledgements
 
 Ruff's linter draws on both the APIs and implementation details of many other
 tools in the Python ecosystem, especially [Flake8](https://github.com/PyCQA/flake8), [Pyflakes](https://github.com/PyCQA/pyflakes),
@@ -418,7 +406,7 @@ Ruff is the beneficiary of a large number of [contributors](https://github.com/a
 
 Ruff is released under the MIT license.
 
-## Who's Using Ruff?<a id="whos-using-ruff"></a>
+## Who's Using Ruff?
 
 Ruff is used by a number of major open-source projects and companies, including:
 
@@ -430,14 +418,12 @@ Ruff is used by a number of major open-source projects and companies, including:
 - [Babel](https://github.com/python-babel/babel)
 - Benchling ([Refac](https://github.com/benchling/refac))
 - [Bokeh](https://github.com/bokeh/bokeh)
-- CrowdCent ([NumerBlox](https://github.com/crowdcent/numerblox)) <!-- typos: ignore -->
 - [Cryptography (PyCA)](https://github.com/pyca/cryptography)
 - CERN ([Indico](https://getindico.io/))
 - [DVC](https://github.com/iterative/dvc)
 - [Dagger](https://github.com/dagger/dagger)
 - [Dagster](https://github.com/dagster-io/dagster)
 - Databricks ([MLflow](https://github.com/mlflow/mlflow))
-- [Dify](https://github.com/langgenius/dify)
 - [FastAPI](https://github.com/tiangolo/fastapi)
 - [Godot](https://github.com/godotengine/godot)
 - [Gradio](https://github.com/gradio-app/gradio)
@@ -448,11 +434,9 @@ Ruff is used by a number of major open-source projects and companies, including:
 - Hugging Face ([Transformers](https://github.com/huggingface/transformers),
     [Datasets](https://github.com/huggingface/datasets),
     [Diffusers](https://github.com/huggingface/diffusers))
-- IBM ([Qiskit](https://github.com/Qiskit/qiskit))
 - ING Bank ([popmon](https://github.com/ing-bank/popmon), [probatus](https://github.com/ing-bank/probatus))
 - [Ibis](https://github.com/ibis-project/ibis)
 - [ivy](https://github.com/unifyai/ivy)
-- [JAX](https://github.com/jax-ml/jax)
 - [Jupyter](https://github.com/jupyter-server/jupyter_server)
 - [Kraken Tech](https://kraken.tech/)
 - [LangChain](https://github.com/hwchase17/langchain)
@@ -539,7 +523,7 @@ If you're using Ruff, consider adding the Ruff badge to your project's `README.m
 <a href="https://github.com/astral-sh/ruff"><img src="https://img.shields.io/endpoint?url=https://raw.githubusercontent.com/astral-sh/ruff/main/assets/badge/v2.json" alt="Ruff" style="max-width:100%;"></a>
 ```
 
-## License<a id="license"></a>
+## License
 
 This repository is licensed under the [MIT License](https://github.com/astral-sh/ruff/blob/main/LICENSE)
 

SECURITY.md

@@ -1,15 +0,0 @@
-# Security policy
-
-## Reporting a vulnerability
-
-If you have found a possible vulnerability, please email `security at astral dot sh`.
-
-## Bug bounties
-
-While we sincerely appreciate and encourage reports of suspected security problems, please note that
-Astral does not currently run any bug bounty programs.
-
-## Vulnerability disclosures
-
-Critical vulnerabilities will be disclosed via GitHub's
-[security advisory](https://github.com/astral-sh/ruff/security) system.

_typos.toml

@@ -1,10 +1,6 @@
 [files]
 # https://github.com/crate-ci/typos/issues/868
-extend-exclude = [
-    "crates/red_knot_vendored/vendor/**/*",
-    "**/resources/**/*",
-    "**/snapshots/**/*",
-]
+extend-exclude = ["crates/red_knot_module_resolver/vendor/**/*", "**/resources/**/*", "**/snapshots/**/*"]
 
 [default.extend-words]
 "arange" = "arange"  # e.g. `numpy.arange`
@@ -12,22 +8,14 @@ hel = "hel"
 whos = "whos"
 spawnve = "spawnve"
 ned = "ned"
-pn = "pn"  # `import panel as pn` is a thing
+pn = "pn"  # `import panel as pd` is a thing
 poit = "poit"
 BA = "BA" # acronym for "Bad Allowed", used in testing.
 jod = "jod" # e.g., `jod-thread`
-Numer = "Numer" # Library name 'NumerBlox' in "Who's Using Ruff?"
 
 [default]
 extend-ignore-re = [
-    # Line ignore with trailing "spellchecker:disable-line"
-    "(?Rm)^.*#\\s*spellchecker:disable-line$",
-    "LICENSEs",
-    # Various third party dependencies uses `typ` as struct field names (e.g., lsp_types::LogMessageParams)
-    "typ",
-    # TODO: Remove this once the `TYP` redirects are removed from `rule_redirects.rs`
-    "TYP",
+  # Line ignore with trailing "spellchecker:disable-line"
+  "(?Rm)^.*#\\s*spellchecker:disable-line$",
+  "LICENSEs",
 ]
-
-[default.extend-identifiers]
-"FrIeNdLy" = "FrIeNdLy"

clippy.toml

@@ -1,25 +1,13 @@
 doc-valid-idents = [
-    "..",
-    "CodeQL",
-    "FastAPI",
-    "IPython",
-    "LangChain",
-    "LibCST",
-    "McCabe",
-    "NumPy",
-    "SCREAMING_SNAKE_CASE",
-    "SQLAlchemy",
-    "StackOverflow",
-    "PyCharm",
-    "SNMPv1",
-    "SNMPv2",
-    "SNMPv3",
-    "PyFlakes"
-]
-
-ignore-interior-mutability = [
-    # Interned is read-only. The wrapped `Rc` never gets updated.
-    "ruff_formatter::format_element::Interned",
-    # The expression is read-only.
-    "ruff_python_ast::hashable::HashableExpr",
+  "..",
+  "CodeQL",
+  "FastAPI",
+  "IPython",
+  "LangChain",
+  "LibCST",
+  "McCabe",
+  "NumPy",
+  "SCREAMING_SNAKE_CASE",
+  "SQLAlchemy",
+  "StackOverflow",
 ]

crates/red_knot/Cargo.toml

@@ -12,38 +12,24 @@ license.workspace = true
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
+red_knot_module_resolver = { workspace = true }
 red_knot_python_semantic = { workspace = true }
-red_knot_project = { workspace = true, features = ["zstd"] }
-red_knot_server = { workspace = true }
-ruff_db = { workspace = true, features = ["os", "cache"] }
+
+ruff_db = { workspace = true }
 ruff_python_ast = { workspace = true }
 
 anyhow = { workspace = true }
-argfile = { workspace = true }
-chrono = { workspace = true }
-clap = { workspace = true, features = ["wrap_help"] }
-colored = { workspace = true }
 countme = { workspace = true, features = ["enable"] }
 crossbeam = { workspace = true }
 ctrlc = { version = "3.4.4" }
+notify = { workspace = true }
 rayon = { workspace = true }
+rustc-hash = { workspace = true }
 salsa = { workspace = true }
-tracing = { workspace = true, features = ["release_max_level_debug"] }
-tracing-subscriber = { workspace = true, features = ["env-filter", "fmt"] }
-tracing-flame = { workspace = true }
+tracing = { workspace = true }
+tracing-subscriber = { workspace = true }
 tracing-tree = { workspace = true }
-wild = { workspace = true }
 
-[dev-dependencies]
-ruff_db = { workspace = true, features = ["testing"] }
-ruff_python_trivia = { workspace = true }
-
-insta = { workspace = true, features = ["filters"] }
-insta-cmd = { workspace = true }
-filetime = { workspace = true }
-regex = { workspace = true }
-tempfile = { workspace = true }
-toml = { workspace = true }
 
 [lints]
 workspace = true

crates/red_knot/README.md

@@ -1,25 +0,0 @@
-# Red Knot
-
-Red Knot is an extremely fast type checker.
-Currently, it is a work-in-progress and not ready for user testing.
-
-Red Knot is designed to prioritize good type inference, even in unannotated code,
-and aims to avoid false positives.
-
-While Red Knot will produce similar results to mypy and pyright on many codebases,
-100% compatibility with these tools is a non-goal.
-On some codebases, Red Knot's design decisions lead to different outcomes
-than you would get from running one of these more established tools.
-
-## Contributing
-
-Core type checking tests are written as Markdown code blocks.
-They can be found in [`red_knot_python_semantic/resources/mdtest`][resources-mdtest].
-See [`red_knot_test/README.md`][mdtest-readme] for more information
-on the test framework itself.
-
-The list of open issues can be found [here][open-issues].
-
-[mdtest-readme]: ../red_knot_test/README.md
-[open-issues]: https://github.com/astral-sh/ruff/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20label%3Ared-knot
-[resources-mdtest]: ../red_knot_python_semantic/resources/mdtest

crates/red_knot/build.rs

@@ -1,104 +0,0 @@
-use std::{
-    fs,
-    path::{Path, PathBuf},
-    process::Command,
-};
-
-fn main() {
-    // The workspace root directory is not available without walking up the tree
-    // https://github.com/rust-lang/cargo/issues/3946
-    let workspace_root = Path::new(&std::env::var("CARGO_MANIFEST_DIR").unwrap())
-        .join("..")
-        .join("..");
-
-    commit_info(&workspace_root);
-
-    #[allow(clippy::disallowed_methods)]
-    let target = std::env::var("TARGET").unwrap();
-    println!("cargo::rustc-env=RUST_HOST_TARGET={target}");
-}
-
-fn commit_info(workspace_root: &Path) {
-    // If not in a git repository, do not attempt to retrieve commit information
-    let git_dir = workspace_root.join(".git");
-    if !git_dir.exists() {
-        return;
-    }
-
-    if let Some(git_head_path) = git_head(&git_dir) {
-        println!("cargo:rerun-if-changed={}", git_head_path.display());
-
-        let git_head_contents = fs::read_to_string(git_head_path);
-        if let Ok(git_head_contents) = git_head_contents {
-            // The contents are either a commit or a reference in the following formats
-            // - "<commit>" when the head is detached
-            // - "ref <ref>" when working on a branch
-            // If a commit, checking if the HEAD file has changed is sufficient
-            // If a ref, we need to add the head file for that ref to rebuild on commit
-            let mut git_ref_parts = git_head_contents.split_whitespace();
-            git_ref_parts.next();
-            if let Some(git_ref) = git_ref_parts.next() {
-                let git_ref_path = git_dir.join(git_ref);
-                println!("cargo:rerun-if-changed={}", git_ref_path.display());
-            }
-        }
-    }
-
-    let output = match Command::new("git")
-        .arg("log")
-        .arg("-1")
-        .arg("--date=short")
-        .arg("--abbrev=9")
-        .arg("--format=%H %h %cd %(describe)")
-        .output()
-    {
-        Ok(output) if output.status.success() => output,
-        _ => return,
-    };
-    let stdout = String::from_utf8(output.stdout).unwrap();
-    let mut parts = stdout.split_whitespace();
-    let mut next = || parts.next().unwrap();
-    let _commit_hash = next();
-    println!("cargo::rustc-env=RED_KNOT_COMMIT_SHORT_HASH={}", next());
-    println!("cargo::rustc-env=RED_KNOT_COMMIT_DATE={}", next());
-
-    // Describe can fail for some commits
-    // https://git-scm.com/docs/pretty-formats#Documentation/pretty-formats.txt-emdescribeoptionsem
-    if let Some(describe) = parts.next() {
-        let mut describe_parts = describe.split('-');
-        let _last_tag = describe_parts.next().unwrap();
-
-        // If this is the tagged commit, this component will be missing
-        println!(
-            "cargo::rustc-env=RED_KNOT_LAST_TAG_DISTANCE={}",
-            describe_parts.next().unwrap_or("0")
-        );
-    }
-}
-
-fn git_head(git_dir: &Path) -> Option<PathBuf> {
-    // The typical case is a standard git repository.
-    let git_head_path = git_dir.join("HEAD");
-    if git_head_path.exists() {
-        return Some(git_head_path);
-    }
-    if !git_dir.is_file() {
-        return None;
-    }
-    // If `.git/HEAD` doesn't exist and `.git` is actually a file,
-    // then let's try to attempt to read it as a worktree. If it's
-    // a worktree, then its contents will look like this, e.g.:
-    //
-    //     gitdir: /home/andrew/astral/uv/main/.git/worktrees/pr2
-    //
-    // And the HEAD file we want to watch will be at:
-    //
-    //     /home/andrew/astral/uv/main/.git/worktrees/pr2/HEAD
-    let contents = fs::read_to_string(git_dir).ok()?;
-    let (label, worktree_path) = contents.split_once(':')?;
-    if label != "gitdir" {
-        return None;
-    }
-    let worktree_path = worktree_path.trim();
-    Some(PathBuf::from(worktree_path))
-}

crates/red_knot/docs/mypy_primer.md

@@ -1,61 +0,0 @@
-# Running `mypy_primer`
-
-## Basics
-
-For now, we use our own [fork of mypy primer]. It can be run using `uvx --from "…" mypy_primer`. For example, to see the help message, run:
-
-```sh
-uvx --from "git+https://github.com/astral-sh/mypy_primer.git@add-red-knot-support" mypy_primer -h
-```
-
-Alternatively, you can install the forked version of `mypy_primer` using:
-
-```sh
-uv tool install "git+https://github.com/astral-sh/mypy_primer.git@add-red-knot-support"
-```
-
-and then run it using `uvx mypy_primer` or just `mypy_primer`, if your `PATH` is set up accordingly (see: [Tool executables]).
-
-## Showing the diagnostics diff between two Git revisions
-
-To show the diagnostics diff between two Git revisions (e.g. your feature branch and `main`), run:
-
-```sh
-mypy_primer \
-    --type-checker knot \
-    --old origin/main \
-    --new my/feature \
-    --debug \
-    --output concise \
-    --project-selector '/black$'
-```
-
-This will show the diagnostics diff for the `black` project between the `main` branch and your `my/feature` branch. To run the
-diff for all projects, you currently need to copy the project-selector regex from the CI pipeline in `.github/workflows/mypy_primer.yaml`.
-
-You can also take a look at the [full list of ecosystem projects]. Note that some of them might still need a `knot_paths` configuration
-option to work correctly.
-
-## Avoiding recompilation
-
-If you want to run `mypy_primer` repeatedly, e.g. for different projects, but for the same combination of `--old` and `--new`, you
-can use set the `MYPY_PRIMER_NO_REBUILD` environment variable to avoid recompilation of Red Knot:
-
-```sh
-MYPY_PRIMER_NO_REBUILD=1 mypy_primer …
-```
-
-## Running from a local copy of the repository
-
-If you are working on a local branch, you can use `mypy_primer`'s `--repo` option to specify the path to your local copy of the `ruff` repository.
-This allows `mypy_primer` to check out local branches:
-
-```sh
-mypy_primer --repo /path/to/ruff --old origin/main --new my/local-branch …
-```
-
-Note that you might need to clean up `/tmp/mypy_primer` in order for this to work correctly.
-
-[fork of mypy primer]: https://github.com/astral-sh/mypy_primer/tree/add-red-knot-support
-[full list of ecosystem projects]: https://github.com/astral-sh/mypy_primer/blob/add-red-knot-support/mypy_primer/projects.py
-[tool executables]: https://docs.astral.sh/uv/concepts/tools/#tool-executables

crates/red_knot/docs/tracing.md

@@ -1,128 +0,0 @@
-# Tracing
-
-Traces are a useful tool to narrow down the location of a bug or, at least, to understand why the compiler is doing a particular thing.
-Note, tracing messages with severity `debug` or greater are user-facing. They should be phrased accordingly.
-Tracing spans are only shown when using `-vvv`.
-
-## Verbosity levels
-
-The CLI supports different verbosity levels.
-
-- default: Only show errors and warnings.
-- `-v` activates `info!`: Show generally useful information such as paths of configuration files, detected platform, etc., but it's not a lot of messages, it's something you'll activate in CI by default. cargo build e.g. shows you which packages are fresh.
-- `-vv` activates `debug!` and timestamps: This should be enough information to get to the bottom of bug reports. When you're processing many packages or files, you'll get pages and pages of output, but each line is link to a specific action or state change.
-- `-vvv` activates `trace!` (only in debug builds) and shows tracing-spans: At this level, you're logging everything. Most of this is wasted, it's really slow, we dump e.g. the entire resolution graph. Only useful to developers, and you almost certainly want to use `RED_KNOT_LOG` to filter it down to the area your investigating.
-
-## Better logging with `RED_KNOT_LOG` and `RAYON_NUM_THREADS`
-
-By default, the CLI shows messages from the `ruff` and `red_knot` crates. Tracing messages from other crates are not shown.
-The `RED_KNOT_LOG` environment variable allows you to customize which messages are shown by specifying one
-or more [filter directives](https://docs.rs/tracing-subscriber/latest/tracing_subscriber/filter/struct.EnvFilter.html#directives).
-
-The `RAYON_NUM_THREADS` environment variable, meanwhile, can be used to control the level of concurrency red-knot uses.
-By default, red-knot will attempt to parallelize its work so that multiple files are checked simultaneously,
-but this can result in a confused logging output where messages from different threads are intertwined.
-To switch off concurrency entirely and have more readable logs, use `RAYON_NUM_THREADS=1`.
-
-### Examples
-
-#### Show all debug messages
-
-Shows debug messages from all crates.
-
-```bash
-RED_KNOT_LOG=debug
-```
-
-#### Show salsa query execution messages
-
-Show the salsa `execute: my_query` messages in addition to all red knot messages.
-
-```bash
-RED_KNOT_LOG=ruff=trace,red_knot=trace,salsa=info
-```
-
-#### Show typing traces
-
-Only show traces for the `red_knot_python_semantic::types` module.
-
-```bash
-RED_KNOT_LOG="red_knot_python_semantic::types"
-```
-
-Note: Ensure that you use `-vvv` to see tracing spans.
-
-#### Show messages for a single file
-
-Shows all messages that are inside of a span for a specific file.
-
-```bash
-RED_KNOT_LOG=red_knot[{file=/home/micha/astral/test/x.py}]=trace
-```
-
-**Note**: Tracing still shows all spans because tracing can't know at the time of entering the span
-whether one if its children has the file `x.py`.
-
-**Note**: Salsa currently logs the entire memoized values. In our case, the source text and parsed AST.
-This very quickly leads to extremely long outputs.
-
-## Tracing and Salsa
-
-Be mindful about using `tracing` in Salsa queries, especially when using `warn` or `error` because it isn't guaranteed
-that the query will execute after restoring from a persistent cache. In which case the user won't see the message.
-
-For example, don't use `tracing` to show the user a message when generating a lint violation failed
-because the message would only be shown when linting the file the first time, but not on subsequent analysis
-runs or when restoring from a persistent cache. This can be confusing for users because they
-don't understand why a specific lint violation isn't raised. Instead, change your
-query to return the failure as part of the query's result or use a Salsa accumulator.
-
-## Tracing in tests
-
-You can use `ruff_db::testing::setup_logging` or `ruff_db::testing::setup_logging_with_filter` to set up logging in tests.
-
-```rust
-use ruff_db::testing::setup_logging;
-
-#[test]
-fn test() {
-  let _logging = setup_logging();
-
-  tracing::info!("This message will be printed to stderr");
-}
-```
-
-Note: Most test runners capture stderr and only show its output when a test fails.
-
-Note also that `setup_logging` only sets up logging for the current thread because [`set_global_default`](https://docs.rs/tracing/latest/tracing/subscriber/fn.set_global_default.html) can only be
-called **once**.
-
-## Release builds
-
-`trace!` events are removed in release builds.
-
-## Profiling
-
-Red Knot generates a folded stack trace to the current directory named `tracing.folded` when setting the environment variable `RED_KNOT_LOG_PROFILE` to `1` or `true`.
-
-```bash
-RED_KNOT_LOG_PROFILE=1 red_knot -- --current-directory=../test -vvv
-```
-
-You can convert the textual representation into a visual one using `inferno`.
-
-```shell
-cargo install inferno
-```
-
-```shell
-# flamegraph
-cat tracing.folded | inferno-flamegraph > tracing-flamegraph.svg
-
-# flamechart
-cat tracing.folded | inferno-flamegraph --flamechart > tracing-flamechart.svg
-```
-
-![Example flamegraph](./tracing-flamegraph.png)
-
-See [`tracing-flame`](https://crates.io/crates/tracing-flame) for more details.

crates/red_knot/src/args.rs

@@ -1,280 +0,0 @@
-use crate::logging::Verbosity;
-use crate::python_version::PythonVersion;
-use clap::{ArgAction, ArgMatches, Error, Parser};
-use red_knot_project::metadata::options::{EnvironmentOptions, Options, TerminalOptions};
-use red_knot_project::metadata::value::{RangedValue, RelativePathBuf};
-use red_knot_python_semantic::lint;
-use ruff_db::system::SystemPathBuf;
-
-#[derive(Debug, Parser)]
-#[command(
-    author,
-    name = "red-knot",
-    about = "An extremely fast Python type checker."
-)]
-#[command(version)]
-pub(crate) struct Args {
-    #[command(subcommand)]
-    pub(crate) command: Command,
-}
-
-#[derive(Debug, clap::Subcommand)]
-pub(crate) enum Command {
-    /// Check a project for type errors.
-    Check(CheckCommand),
-
-    /// Start the language server
-    Server,
-
-    /// Display Red Knot's version
-    Version,
-}
-
-#[derive(Debug, Parser)]
-pub(crate) struct CheckCommand {
-    /// List of files or directories to check.
-    #[clap(
-        help = "List of files or directories to check [default: the project root]",
-        value_name = "PATH"
-    )]
-    pub paths: Vec<SystemPathBuf>,
-
-    /// Run the command within the given project directory.
-    ///
-    /// All `pyproject.toml` files will be discovered by walking up the directory tree from the given project directory,
-    /// as will the project's virtual environment (`.venv`) unless the `venv-path` option is set.
-    ///
-    /// Other command-line arguments (such as relative paths) will be resolved relative to the current working directory.
-    #[arg(long, value_name = "PROJECT")]
-    pub(crate) project: Option<SystemPathBuf>,
-
-    /// Path to the Python installation from which Red Knot resolves type information and third-party dependencies.
-    ///
-    /// If not specified, Red Knot will look at the `VIRTUAL_ENV` environment variable.
-    ///
-    /// Red Knot will search in the path's `site-packages` directories for type information and
-    /// third-party imports.
-    ///
-    /// This option is commonly used to specify the path to a virtual environment.
-    #[arg(long, value_name = "PATH")]
-    pub(crate) python: Option<SystemPathBuf>,
-
-    /// Custom directory to use for stdlib typeshed stubs.
-    #[arg(long, value_name = "PATH", alias = "custom-typeshed-dir")]
-    pub(crate) typeshed: Option<SystemPathBuf>,
-
-    /// Additional path to use as a module-resolution source (can be passed multiple times).
-    #[arg(long, value_name = "PATH")]
-    pub(crate) extra_search_path: Option<Vec<SystemPathBuf>>,
-
-    /// Python version to assume when resolving types.
-    #[arg(long, value_name = "VERSION", alias = "target-version")]
-    pub(crate) python_version: Option<PythonVersion>,
-
-    /// Target platform to assume when resolving types.
-    ///
-    /// This is used to specialize the type of `sys.platform` and will affect the visibility
-    /// of platform-specific functions and attributes. If the value is set to `all`, no
-    /// assumptions are made about the target platform. If unspecified, the current system's
-    /// platform will be used.
-    #[arg(long, value_name = "PLATFORM", alias = "platform")]
-    pub(crate) python_platform: Option<String>,
-
-    #[clap(flatten)]
-    pub(crate) verbosity: Verbosity,
-
-    #[clap(flatten)]
-    pub(crate) rules: RulesArg,
-
-    /// The format to use for printing diagnostic messages.
-    #[arg(long)]
-    pub(crate) output_format: Option<OutputFormat>,
-
-    /// Control when colored output is used.
-    #[arg(long, value_name = "WHEN")]
-    pub(crate) color: Option<TerminalColor>,
-
-    /// Use exit code 1 if there are any warning-level diagnostics.
-    #[arg(long, conflicts_with = "exit_zero", default_missing_value = "true", num_args=0..1)]
-    pub(crate) error_on_warning: Option<bool>,
-
-    /// Always use exit code 0, even when there are error-level diagnostics.
-    #[arg(long)]
-    pub(crate) exit_zero: bool,
-
-    /// Watch files for changes and recheck files related to the changed files.
-    #[arg(long, short = 'W')]
-    pub(crate) watch: bool,
-}
-
-impl CheckCommand {
-    pub(crate) fn into_options(self) -> Options {
-        let rules = if self.rules.is_empty() {
-            None
-        } else {
-            Some(
-                self.rules
-                    .into_iter()
-                    .map(|(rule, level)| (RangedValue::cli(rule), RangedValue::cli(level)))
-                    .collect(),
-            )
-        };
-
-        Options {
-            environment: Some(EnvironmentOptions {
-                python_version: self
-                    .python_version
-                    .map(|version| RangedValue::cli(version.into())),
-                python_platform: self
-                    .python_platform
-                    .map(|platform| RangedValue::cli(platform.into())),
-                python: self.python.map(RelativePathBuf::cli),
-                typeshed: self.typeshed.map(RelativePathBuf::cli),
-                extra_paths: self.extra_search_path.map(|extra_search_paths| {
-                    extra_search_paths
-                        .into_iter()
-                        .map(RelativePathBuf::cli)
-                        .collect()
-                }),
-            }),
-            terminal: Some(TerminalOptions {
-                output_format: self
-                    .output_format
-                    .map(|output_format| RangedValue::cli(output_format.into())),
-                error_on_warning: self.error_on_warning,
-            }),
-            rules,
-            ..Default::default()
-        }
-    }
-}
-
-/// A list of rules to enable or disable with a given severity.
-///
-/// This type is used to parse the `--error`, `--warn`, and `--ignore` arguments
-/// while preserving the order in which they were specified (arguments last override previous severities).
-#[derive(Debug)]
-pub(crate) struct RulesArg(Vec<(String, lint::Level)>);
-
-impl RulesArg {
-    fn is_empty(&self) -> bool {
-        self.0.is_empty()
-    }
-
-    fn into_iter(self) -> impl Iterator<Item = (String, lint::Level)> {
-        self.0.into_iter()
-    }
-}
-
-impl clap::FromArgMatches for RulesArg {
-    fn from_arg_matches(matches: &ArgMatches) -> Result<Self, Error> {
-        let mut rules = Vec::new();
-
-        for (level, arg_id) in [
-            (lint::Level::Ignore, "ignore"),
-            (lint::Level::Warn, "warn"),
-            (lint::Level::Error, "error"),
-        ] {
-            let indices = matches.indices_of(arg_id).into_iter().flatten();
-            let levels = matches.get_many::<String>(arg_id).into_iter().flatten();
-            rules.extend(
-                indices
-                    .zip(levels)
-                    .map(|(index, rule)| (index, rule, level)),
-            );
-        }
-
-        // Sort by their index so that values specified later override earlier ones.
-        rules.sort_by_key(|(index, _, _)| *index);
-
-        Ok(Self(
-            rules
-                .into_iter()
-                .map(|(_, rule, level)| (rule.to_owned(), level))
-                .collect(),
-        ))
-    }
-
-    fn update_from_arg_matches(&mut self, matches: &ArgMatches) -> Result<(), Error> {
-        self.0 = Self::from_arg_matches(matches)?.0;
-        Ok(())
-    }
-}
-
-impl clap::Args for RulesArg {
-    fn augment_args(cmd: clap::Command) -> clap::Command {
-        const HELP_HEADING: &str = "Enabling / disabling rules";
-
-        cmd.arg(
-            clap::Arg::new("error")
-                .long("error")
-                .action(ArgAction::Append)
-                .help("Treat the given rule as having severity 'error'. Can be specified multiple times.")
-                .value_name("RULE")
-                .help_heading(HELP_HEADING),
-        )
-        .arg(
-            clap::Arg::new("warn")
-                .long("warn")
-                .action(ArgAction::Append)
-                .help("Treat the given rule as having severity 'warn'. Can be specified multiple times.")
-                .value_name("RULE")
-                .help_heading(HELP_HEADING),
-        )
-        .arg(
-            clap::Arg::new("ignore")
-                .long("ignore")
-                .action(ArgAction::Append)
-                .help("Disables the rule. Can be specified multiple times.")
-                .value_name("RULE")
-                .help_heading(HELP_HEADING),
-        )
-    }
-
-    fn augment_args_for_update(cmd: clap::Command) -> clap::Command {
-        Self::augment_args(cmd)
-    }
-}
-
-/// The diagnostic output format.
-#[derive(Copy, Clone, Hash, Debug, PartialEq, Eq, PartialOrd, Ord, Default, clap::ValueEnum)]
-pub enum OutputFormat {
-    /// Print diagnostics verbosely, with context and helpful hints.
-    ///
-    /// Diagnostic messages may include additional context and
-    /// annotations on the input to help understand the message.
-    #[default]
-    #[value(name = "full")]
-    Full,
-    /// Print diagnostics concisely, one per line.
-    ///
-    /// This will guarantee that each diagnostic is printed on
-    /// a single line. Only the most important or primary aspects
-    /// of the diagnostic are included. Contextual information is
-    /// dropped.
-    #[value(name = "concise")]
-    Concise,
-}
-
-impl From<OutputFormat> for ruff_db::diagnostic::DiagnosticFormat {
-    fn from(format: OutputFormat) -> ruff_db::diagnostic::DiagnosticFormat {
-        match format {
-            OutputFormat::Full => Self::Full,
-            OutputFormat::Concise => Self::Concise,
-        }
-    }
-}
-
-/// Control when colored output is used.
-#[derive(Copy, Clone, Hash, Debug, PartialEq, Eq, PartialOrd, Ord, Default, clap::ValueEnum)]
-pub(crate) enum TerminalColor {
-    /// Display colors if the output goes to an interactive terminal.
-    #[default]
-    Auto,
-
-    /// Always display colors.
-    Always,
-
-    /// Never display colors.
-    Never,
-}

crates/red_knot/src/db.rs

@@ -0,0 +1,10 @@
+use red_knot_python_semantic::Db as SemanticDb;
+use ruff_db::Upcast;
+use salsa::DbWithJar;
+
+use crate::lint::{lint_semantic, lint_syntax, unwind_if_cancelled};
+
+pub trait Db: DbWithJar<Jar> + SemanticDb + Upcast<dyn SemanticDb> {}
+
+#[salsa::jar(db=Db)]
+pub struct Jar(lint_syntax, lint_semantic, unwind_if_cancelled);

crates/red_knot/src/lib.rs

@@ -0,0 +1,52 @@
+use rustc_hash::FxHashSet;
+
+use ruff_db::file_system::{FileSystemPath, FileSystemPathBuf};
+use ruff_db::vfs::VfsFile;
+
+use crate::db::Jar;
+
+pub mod db;
+pub mod lint;
+pub mod program;
+pub mod watch;
+
+#[derive(Debug, Clone)]
+pub struct Workspace {
+    root: FileSystemPathBuf,
+    /// The files that are open in the workspace.
+    ///
+    /// * Editor: The files that are actively being edited in the editor (the user has a tab open with the file).
+    /// * CLI: The resolved files passed as arguments to the CLI.
+    open_files: FxHashSet<VfsFile>,
+}
+
+impl Workspace {
+    pub fn new(root: FileSystemPathBuf) -> Self {
+        Self {
+            root,
+            open_files: FxHashSet::default(),
+        }
+    }
+
+    pub fn root(&self) -> &FileSystemPath {
+        self.root.as_path()
+    }
+
+    // TODO having the content in workspace feels wrong.
+    pub fn open_file(&mut self, file_id: VfsFile) {
+        self.open_files.insert(file_id);
+    }
+
+    pub fn close_file(&mut self, file_id: VfsFile) {
+        self.open_files.remove(&file_id);
+    }
+
+    // TODO introduce an `OpenFile` type instead of using an anonymous tuple.
+    pub fn open_files(&self) -> impl Iterator<Item = VfsFile> + '_ {
+        self.open_files.iter().copied()
+    }
+
+    pub fn is_file_open(&self, file_id: VfsFile) -> bool {
+        self.open_files.contains(&file_id)
+    }
+}

crates/red_knot/src/lint.rs

@@ -0,0 +1,275 @@
+use std::cell::RefCell;
+use std::ops::Deref;
+use std::time::Duration;
+
+use tracing::trace_span;
+
+use red_knot_module_resolver::ModuleName;
+use red_knot_python_semantic::types::Type;
+use red_knot_python_semantic::{HasTy, SemanticModel};
+use ruff_db::parsed::{parsed_module, ParsedModule};
+use ruff_db::source::{source_text, SourceText};
+use ruff_db::vfs::VfsFile;
+use ruff_python_ast as ast;
+use ruff_python_ast::visitor::{walk_stmt, Visitor};
+
+use crate::db::Db;
+
+/// Workaround query to test for if the computation should be cancelled.
+/// Ideally, push for Salsa to expose an API for testing if cancellation was requested.
+#[salsa::tracked]
+#[allow(unused_variables)]
+pub(crate) fn unwind_if_cancelled(db: &dyn Db) {}
+
+#[salsa::tracked(return_ref)]
+pub(crate) fn lint_syntax(db: &dyn Db, file_id: VfsFile) -> Diagnostics {
+    #[allow(clippy::print_stdout)]
+    if std::env::var("RED_KNOT_SLOW_LINT").is_ok() {
+        for i in 0..10 {
+            unwind_if_cancelled(db);
+
+            println!("RED_KNOT_SLOW_LINT is set, sleeping for {i}/10 seconds");
+            std::thread::sleep(Duration::from_secs(1));
+        }
+    }
+
+    let mut diagnostics = Vec::new();
+
+    let source = source_text(db.upcast(), file_id);
+    lint_lines(&source, &mut diagnostics);
+
+    let parsed = parsed_module(db.upcast(), file_id);
+
+    if parsed.errors().is_empty() {
+        let ast = parsed.syntax();
+
+        let mut visitor = SyntaxLintVisitor {
+            diagnostics,
+            source: &source,
+        };
+        visitor.visit_body(&ast.body);
+        diagnostics = visitor.diagnostics;
+    } else {
+        diagnostics.extend(parsed.errors().iter().map(ToString::to_string));
+    }
+
+    Diagnostics::from(diagnostics)
+}
+
+fn lint_lines(source: &str, diagnostics: &mut Vec<String>) {
+    for (line_number, line) in source.lines().enumerate() {
+        if line.len() < 88 {
+            continue;
+        }
+
+        let char_count = line.chars().count();
+        if char_count > 88 {
+            diagnostics.push(format!(
+                "Line {} is too long ({} characters)",
+                line_number + 1,
+                char_count
+            ));
+        }
+    }
+}
+
+#[salsa::tracked(return_ref)]
+pub(crate) fn lint_semantic(db: &dyn Db, file_id: VfsFile) -> Diagnostics {
+    let _span = trace_span!("lint_semantic", ?file_id).entered();
+
+    let source = source_text(db.upcast(), file_id);
+    let parsed = parsed_module(db.upcast(), file_id);
+    let semantic = SemanticModel::new(db.upcast(), file_id);
+
+    if !parsed.is_valid() {
+        return Diagnostics::Empty;
+    }
+
+    let context = SemanticLintContext {
+        source,
+        parsed,
+        semantic,
+        diagnostics: RefCell::new(Vec::new()),
+    };
+
+    SemanticVisitor { context: &context }.visit_body(parsed.suite());
+
+    Diagnostics::from(context.diagnostics.take())
+}
+
+fn lint_unresolved_imports(context: &SemanticLintContext, import: AnyImportRef) {
+    match import {
+        AnyImportRef::Import(import) => {
+            for alias in &import.names {
+                let ty = alias.ty(&context.semantic);
+
+                if ty.is_unknown() {
+                    context.push_diagnostic(format!("Unresolved import '{}'", &alias.name));
+                }
+            }
+        }
+        AnyImportRef::ImportFrom(import) => {
+            for alias in &import.names {
+                let ty = alias.ty(&context.semantic);
+
+                if ty.is_unknown() {
+                    context.push_diagnostic(format!("Unresolved import '{}'", &alias.name));
+                }
+            }
+        }
+    }
+}
+
+fn lint_bad_override(context: &SemanticLintContext, class: &ast::StmtClassDef) {
+    let semantic = &context.semantic;
+
+    // TODO we should have a special marker on the real typing module (from typeshed) so if you
+    //   have your own "typing" module in your project, we don't consider it THE typing module (and
+    //   same for other stdlib modules that our lint rules care about)
+    let Some(typing) = semantic.resolve_module(ModuleName::new("typing").unwrap()) else {
+        return;
+    };
+
+    let Some(typing_override) = semantic.public_symbol(&typing, "override") else {
+        return;
+    };
+
+    let override_ty = semantic.public_symbol_ty(typing_override);
+
+    let Type::Class(class_ty) = class.ty(semantic) else {
+        return;
+    };
+
+    for function in class
+        .body
+        .iter()
+        .filter_map(|stmt| stmt.as_function_def_stmt())
+    {
+        let Type::Function(ty) = function.ty(semantic) else {
+            return;
+        };
+
+        // TODO this shouldn't make direct use of the Db; see comment on SemanticModel::db
+        let db = semantic.db();
+
+        if ty.has_decorator(db, override_ty) {
+            let method_name = ty.name(db);
+            if class_ty.inherited_class_member(db, &method_name).is_none() {
+                // TODO should have a qualname() method to support nested classes
+                context.push_diagnostic(
+                    format!(
+                        "Method {}.{} is decorated with `typing.override` but does not override any base class method",
+                        class_ty.name(db),
+                        method_name,
+                    ));
+            }
+        }
+    }
+}
+
+pub(crate) struct SemanticLintContext<'a> {
+    source: SourceText,
+    parsed: &'a ParsedModule,
+    semantic: SemanticModel<'a>,
+    diagnostics: RefCell<Vec<String>>,
+}
+
+impl<'db> SemanticLintContext<'db> {
+    #[allow(unused)]
+    pub(crate) fn source_text(&self) -> &str {
+        self.source.as_str()
+    }
+
+    #[allow(unused)]
+    pub(crate) fn ast(&self) -> &'db ast::ModModule {
+        self.parsed.syntax()
+    }
+
+    pub(crate) fn push_diagnostic(&self, diagnostic: String) {
+        self.diagnostics.borrow_mut().push(diagnostic);
+    }
+
+    #[allow(unused)]
+    pub(crate) fn extend_diagnostics(&mut self, diagnostics: impl IntoIterator<Item = String>) {
+        self.diagnostics.get_mut().extend(diagnostics);
+    }
+}
+
+#[derive(Debug)]
+struct SyntaxLintVisitor<'a> {
+    diagnostics: Vec<String>,
+    source: &'a str,
+}
+
+impl Visitor<'_> for SyntaxLintVisitor<'_> {
+    fn visit_string_literal(&mut self, string_literal: &'_ ast::StringLiteral) {
+        // A very naive implementation of use double quotes
+        let text = &self.source[string_literal.range];
+
+        if text.starts_with('\'') {
+            self.diagnostics
+                .push("Use double quotes for strings".to_string());
+        }
+    }
+}
+
+struct SemanticVisitor<'a> {
+    context: &'a SemanticLintContext<'a>,
+}
+
+impl Visitor<'_> for SemanticVisitor<'_> {
+    fn visit_stmt(&mut self, stmt: &ast::Stmt) {
+        match stmt {
+            ast::Stmt::ClassDef(class) => {
+                lint_bad_override(self.context, class);
+            }
+            ast::Stmt::Import(import) => {
+                lint_unresolved_imports(self.context, AnyImportRef::Import(import));
+            }
+            ast::Stmt::ImportFrom(import) => {
+                lint_unresolved_imports(self.context, AnyImportRef::ImportFrom(import));
+            }
+            _ => {}
+        }
+
+        walk_stmt(self, stmt);
+    }
+}
+
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub enum Diagnostics {
+    Empty,
+    List(Vec<String>),
+}
+
+impl Diagnostics {
+    pub fn as_slice(&self) -> &[String] {
+        match self {
+            Diagnostics::Empty => &[],
+            Diagnostics::List(list) => list.as_slice(),
+        }
+    }
+}
+
+impl Deref for Diagnostics {
+    type Target = [String];
+    fn deref(&self) -> &Self::Target {
+        self.as_slice()
+    }
+}
+
+impl From<Vec<String>> for Diagnostics {
+    fn from(value: Vec<String>) -> Self {
+        if value.is_empty() {
+            Diagnostics::Empty
+        } else {
+            Diagnostics::List(value)
+        }
+    }
+}
+
+#[derive(Copy, Clone, Debug)]
+enum AnyImportRef<'a> {
+    Import(&'a ast::StmtImport),
+    ImportFrom(&'a ast::StmtImportFrom),
+}

crates/red_knot/src/logging.rs

@@ -1,254 +0,0 @@
-//! Sets up logging for Red Knot
-
-use anyhow::Context;
-use colored::Colorize;
-use std::fmt;
-use std::fs::File;
-use std::io::BufWriter;
-use tracing::{Event, Subscriber};
-use tracing_subscriber::filter::LevelFilter;
-use tracing_subscriber::fmt::format::Writer;
-use tracing_subscriber::fmt::{FmtContext, FormatEvent, FormatFields};
-use tracing_subscriber::registry::LookupSpan;
-use tracing_subscriber::EnvFilter;
-
-/// Logging flags to `#[command(flatten)]` into your CLI
-#[derive(clap::Args, Debug, Clone, Default)]
-#[command(about = None, long_about = None)]
-pub(crate) struct Verbosity {
-    #[arg(
-        long,
-        short = 'v',
-        help = "Use verbose output (or `-vv` and `-vvv` for more verbose output)",
-        action = clap::ArgAction::Count,
-        global = true,
-    )]
-    verbose: u8,
-}
-
-impl Verbosity {
-    /// Returns the verbosity level based on the number of `-v` flags.
-    ///
-    /// Returns `None` if the user did not specify any verbosity flags.
-    pub(crate) fn level(&self) -> VerbosityLevel {
-        match self.verbose {
-            0 => VerbosityLevel::Default,
-            1 => VerbosityLevel::Verbose,
-            2 => VerbosityLevel::ExtraVerbose,
-            _ => VerbosityLevel::Trace,
-        }
-    }
-}
-
-#[derive(Debug, Copy, Clone, Eq, PartialEq, Ord, PartialOrd)]
-pub(crate) enum VerbosityLevel {
-    /// Default output level. Only shows Ruff and Red Knot events up to the [`WARN`](tracing::Level::WARN).
-    Default,
-
-    /// Enables verbose output. Emits Ruff and Red Knot events up to the [`INFO`](tracing::Level::INFO).
-    /// Corresponds to `-v`.
-    Verbose,
-
-    /// Enables a more verbose tracing format and emits Ruff and Red Knot events up to [`DEBUG`](tracing::Level::DEBUG).
-    /// Corresponds to `-vv`
-    ExtraVerbose,
-
-    /// Enables all tracing events and uses a tree-like output format. Corresponds to `-vvv`.
-    Trace,
-}
-
-impl VerbosityLevel {
-    const fn level_filter(self) -> LevelFilter {
-        match self {
-            VerbosityLevel::Default => LevelFilter::WARN,
-            VerbosityLevel::Verbose => LevelFilter::INFO,
-            VerbosityLevel::ExtraVerbose => LevelFilter::DEBUG,
-            VerbosityLevel::Trace => LevelFilter::TRACE,
-        }
-    }
-
-    pub(crate) const fn is_trace(self) -> bool {
-        matches!(self, VerbosityLevel::Trace)
-    }
-
-    pub(crate) const fn is_extra_verbose(self) -> bool {
-        matches!(self, VerbosityLevel::ExtraVerbose)
-    }
-}
-
-pub(crate) fn setup_tracing(level: VerbosityLevel) -> anyhow::Result<TracingGuard> {
-    use tracing_subscriber::prelude::*;
-
-    // The `RED_KNOT_LOG` environment variable overrides the default log level.
-    let filter = if let Ok(log_env_variable) = std::env::var("RED_KNOT_LOG") {
-        EnvFilter::builder()
-            .parse(log_env_variable)
-            .context("Failed to parse directives specified in RED_KNOT_LOG environment variable.")?
-    } else {
-        match level {
-            VerbosityLevel::Default => {
-                // Show warning traces
-                EnvFilter::default().add_directive(LevelFilter::WARN.into())
-            }
-            level => {
-                let level_filter = level.level_filter();
-
-                // Show info|debug|trace events, but allow `RED_KNOT_LOG` to override
-                let filter = EnvFilter::default().add_directive(
-                    format!("red_knot={level_filter}")
-                        .parse()
-                        .expect("Hardcoded directive to be valid"),
-                );
-
-                filter.add_directive(
-                    format!("ruff={level_filter}")
-                        .parse()
-                        .expect("Hardcoded directive to be valid"),
-                )
-            }
-        }
-    };
-
-    let (profiling_layer, guard) = setup_profile();
-
-    let registry = tracing_subscriber::registry()
-        .with(filter)
-        .with(profiling_layer);
-
-    if level.is_trace() {
-        let subscriber = registry.with(
-            tracing_tree::HierarchicalLayer::default()
-                .with_indent_lines(true)
-                .with_indent_amount(2)
-                .with_bracketed_fields(true)
-                .with_thread_ids(true)
-                .with_targets(true)
-                .with_writer(std::io::stderr)
-                .with_timer(tracing_tree::time::Uptime::default()),
-        );
-
-        subscriber.init();
-    } else {
-        let subscriber = registry.with(
-            tracing_subscriber::fmt::layer()
-                .event_format(RedKnotFormat {
-                    display_level: true,
-                    display_timestamp: level.is_extra_verbose(),
-                    show_spans: false,
-                })
-                .with_writer(std::io::stderr),
-        );
-
-        subscriber.init();
-    }
-
-    Ok(TracingGuard {
-        _flame_guard: guard,
-    })
-}
-
-#[allow(clippy::type_complexity)]
-fn setup_profile<S>() -> (
-    Option<tracing_flame::FlameLayer<S, BufWriter<File>>>,
-    Option<tracing_flame::FlushGuard<BufWriter<File>>>,
-)
-where
-    S: Subscriber + for<'span> LookupSpan<'span>,
-{
-    if let Ok("1" | "true") = std::env::var("RED_KNOT_LOG_PROFILE").as_deref() {
-        let (layer, guard) = tracing_flame::FlameLayer::with_file("tracing.folded")
-            .expect("Flame layer to be created");
-        (Some(layer), Some(guard))
-    } else {
-        (None, None)
-    }
-}
-
-pub(crate) struct TracingGuard {
-    _flame_guard: Option<tracing_flame::FlushGuard<BufWriter<File>>>,
-}
-
-struct RedKnotFormat {
-    display_timestamp: bool,
-    display_level: bool,
-    show_spans: bool,
-}
-
-/// See <https://docs.rs/tracing-subscriber/0.3.18/src/tracing_subscriber/fmt/format/mod.rs.html#1026-1156>
-impl<S, N> FormatEvent<S, N> for RedKnotFormat
-where
-    S: Subscriber + for<'a> LookupSpan<'a>,
-    N: for<'a> FormatFields<'a> + 'static,
-{
-    fn format_event(
-        &self,
-        ctx: &FmtContext<'_, S, N>,
-        mut writer: Writer<'_>,
-        event: &Event<'_>,
-    ) -> fmt::Result {
-        let meta = event.metadata();
-        let ansi = writer.has_ansi_escapes();
-
-        if self.display_timestamp {
-            let timestamp = chrono::Local::now()
-                .format("%Y-%m-%d %H:%M:%S.%f")
-                .to_string();
-            if ansi {
-                write!(writer, "{} ", timestamp.dimmed())?;
-            } else {
-                write!(
-                    writer,
-                    "{} ",
-                    chrono::Local::now().format("%Y-%m-%d %H:%M:%S.%f")
-                )?;
-            }
-        }
-
-        if self.display_level {
-            let level = meta.level();
-            // Same colors as tracing
-            if ansi {
-                let formatted_level = level.to_string();
-                match *level {
-                    tracing::Level::TRACE => {
-                        write!(writer, "{} ", formatted_level.purple().bold())?;
-                    }
-                    tracing::Level::DEBUG => write!(writer, "{} ", formatted_level.blue().bold())?,
-                    tracing::Level::INFO => write!(writer, "{} ", formatted_level.green().bold())?,
-                    tracing::Level::WARN => write!(writer, "{} ", formatted_level.yellow().bold())?,
-                    tracing::Level::ERROR => write!(writer, "{} ", level.to_string().red().bold())?,
-                }
-            } else {
-                write!(writer, "{level} ")?;
-            }
-        }
-
-        if self.show_spans {
-            let span = event.parent();
-            let mut seen = false;
-
-            let span = span
-                .and_then(|id| ctx.span(id))
-                .or_else(|| ctx.lookup_current());
-
-            let scope = span.into_iter().flat_map(|span| span.scope().from_root());
-
-            for span in scope {
-                seen = true;
-                if ansi {
-                    write!(writer, "{}:", span.metadata().name().bold())?;
-                } else {
-                    write!(writer, "{}:", span.metadata().name())?;
-                }
-            }
-
-            if seen {
-                writer.write_char(' ')?;
-            }
-        }
-
-        ctx.field_format().format_fields(writer.by_ref(), event)?;
-
-        writeln!(writer)
-    }
-}

crates/red_knot/src/main.rs

@@ -1,138 +1,77 @@
-use std::io::{self, stdout, BufWriter, Write};
-use std::process::{ExitCode, Termination};
-
-use anyhow::Result;
 use std::sync::Mutex;
 
-use crate::args::{Args, CheckCommand, Command, TerminalColor};
-use crate::logging::setup_tracing;
-use anyhow::{anyhow, Context};
-use clap::Parser;
-use colored::Colorize;
 use crossbeam::channel as crossbeam_channel;
-use red_knot_project::metadata::options::Options;
-use red_knot_project::watch::ProjectWatcher;
-use red_knot_project::{watch, Db};
-use red_knot_project::{ProjectDatabase, ProjectMetadata};
-use red_knot_server::run_server;
-use ruff_db::diagnostic::{Diagnostic, DisplayDiagnosticConfig, Severity};
-use ruff_db::system::{OsSystem, SystemPath, SystemPathBuf};
-use salsa::plumbing::ZalsaDatabase;
+use salsa::ParallelDatabase;
+use tracing::subscriber::Interest;
+use tracing::{Level, Metadata};
+use tracing_subscriber::filter::LevelFilter;
+use tracing_subscriber::layer::{Context, Filter, SubscriberExt};
+use tracing_subscriber::{Layer, Registry};
+use tracing_tree::time::Uptime;
 
-mod args;
-mod logging;
-mod python_version;
-mod version;
+use red_knot::program::{FileWatcherChange, Program};
+use red_knot::watch::FileWatcher;
+use red_knot::Workspace;
+use red_knot_module_resolver::{
+    set_module_resolution_settings, RawModuleResolutionSettings, TargetVersion,
+};
+use ruff_db::file_system::{FileSystem, FileSystemPath, OsFileSystem};
+use ruff_db::vfs::system_path_to_file;
 
-#[allow(clippy::print_stdout, clippy::unnecessary_wraps, clippy::print_stderr)]
-pub fn main() -> ExitStatus {
-    run().unwrap_or_else(|error| {
-        use std::io::Write;
+#[allow(
+    clippy::print_stdout,
+    clippy::unnecessary_wraps,
+    clippy::print_stderr,
+    clippy::dbg_macro
+)]
+pub fn main() -> anyhow::Result<()> {
+    countme::enable(true);
+    setup_tracing();
 
-        // Use `writeln` instead of `eprintln` to avoid panicking when the stderr pipe is broken.
-        let mut stderr = std::io::stderr().lock();
+    let arguments: Vec<_> = std::env::args().collect();
 
-        // This communicates that this isn't a linter error but Red Knot itself hard-errored for
-        // some reason (e.g. failed to resolve the configuration)
-        writeln!(stderr, "{}", "Red Knot failed".red().bold()).ok();
-        // Currently we generally only see one error, but e.g. with io errors when resolving
-        // the configuration it is help to chain errors ("resolving configuration failed" ->
-        // "failed to read file: subdir/pyproject.toml")
-        for cause in error.chain() {
-            // Exit "gracefully" on broken pipe errors.
-            //
-            // See: https://github.com/BurntSushi/ripgrep/blob/bf63fe8f258afc09bae6caa48f0ae35eaf115005/crates/core/main.rs#L47C1-L61C14
-            if let Some(ioerr) = cause.downcast_ref::<io::Error>() {
-                if ioerr.kind() == io::ErrorKind::BrokenPipe {
-                    return ExitStatus::Success;
-                }
-            }
-
-            writeln!(stderr, "  {} {cause}", "Cause:".bold()).ok();
-        }
-
-        ExitStatus::Error
-    })
-}
-
-fn run() -> anyhow::Result<ExitStatus> {
-    let args = wild::args_os();
-    let args = argfile::expand_args_from(args, argfile::parse_fromfile, argfile::PREFIX)
-        .context("Failed to read CLI arguments from file")?;
-    let args = Args::parse_from(args);
-
-    match args.command {
-        Command::Server => run_server().map(|()| ExitStatus::Success),
-        Command::Check(check_args) => run_check(check_args),
-        Command::Version => version().map(|()| ExitStatus::Success),
-    }
-}
-
-pub(crate) fn version() -> Result<()> {
-    let mut stdout = BufWriter::new(io::stdout().lock());
-    let version_info = crate::version::version();
-    writeln!(stdout, "red knot {}", &version_info)?;
-    Ok(())
-}
-
-fn run_check(args: CheckCommand) -> anyhow::Result<ExitStatus> {
-    set_colored_override(args.color);
-
-    let verbosity = args.verbosity.level();
-    countme::enable(verbosity.is_trace());
-    let _guard = setup_tracing(verbosity)?;
-
-    tracing::debug!("Version: {}", version::version());
-
-    // The base path to which all CLI arguments are relative to.
-    let cwd = {
-        let cwd = std::env::current_dir().context("Failed to get the current working directory")?;
-        SystemPathBuf::from_path_buf(cwd)
-            .map_err(|path| {
-                anyhow!(
-                    "The current working directory `{}` contains non-Unicode characters. Red Knot only supports Unicode paths.",
-                    path.display()
-                )
-            })?
-    };
-
-    let project_path = args
-        .project
-        .as_ref()
-        .map(|project| {
-            if project.as_std_path().is_dir() {
-                Ok(SystemPath::absolute(project, &cwd))
-            } else {
-                Err(anyhow!(
-                    "Provided project path `{project}` is not a directory"
-                ))
-            }
-        })
-        .transpose()?
-        .unwrap_or_else(|| cwd.clone());
-
-    let check_paths: Vec<_> = args
-        .paths
-        .iter()
-        .map(|path| SystemPath::absolute(path, &cwd))
-        .collect();
-
-    let system = OsSystem::new(cwd);
-    let watch = args.watch;
-    let exit_zero = args.exit_zero;
-
-    let cli_options = args.into_options();
-    let mut project_metadata = ProjectMetadata::discover(&project_path, &system)?;
-    project_metadata.apply_cli_options(cli_options.clone());
-    project_metadata.apply_configuration_files(&system)?;
-
-    let mut db = ProjectDatabase::new(project_metadata, system)?;
-
-    if !check_paths.is_empty() {
-        db.project().set_included_paths(&mut db, check_paths);
+    if arguments.len() < 2 {
+        eprintln!("Usage: red_knot <path>");
+        return Err(anyhow::anyhow!("Invalid arguments"));
     }
 
-    let (main_loop, main_loop_cancellation_token) = MainLoop::new(cli_options);
+    let fs = OsFileSystem;
+    let entry_point = FileSystemPath::new(&arguments[1]);
+
+    if !fs.exists(entry_point) {
+        eprintln!("The entry point does not exist.");
+        return Err(anyhow::anyhow!("Invalid arguments"));
+    }
+
+    if !fs.is_file(entry_point) {
+        eprintln!("The entry point is not a file.");
+        return Err(anyhow::anyhow!("Invalid arguments"));
+    }
+
+    let entry_point = entry_point.to_path_buf();
+
+    let workspace_folder = entry_point.parent().unwrap();
+    let workspace = Workspace::new(workspace_folder.to_path_buf());
+
+    let workspace_search_path = workspace.root().to_path_buf();
+
+    let mut program = Program::new(workspace, fs);
+
+    set_module_resolution_settings(
+        &mut program,
+        RawModuleResolutionSettings {
+            extra_paths: vec![],
+            workspace_root: workspace_search_path,
+            site_packages: None,
+            custom_typeshed: None,
+            target_version: TargetVersion::Py38,
+        },
+    );
+
+    let entry_id = system_path_to_file(&program, entry_point.clone()).unwrap();
+    program.workspace_mut().open_file(entry_id);
+
+    let (main_loop, main_loop_cancellation_token) = MainLoop::new();
 
     // Listen to Ctrl+C and abort the watch mode.
     let main_loop_cancellation_token = Mutex::new(Some(main_loop_cancellation_token));
@@ -144,201 +83,121 @@ fn run_check(args: CheckCommand) -> anyhow::Result<ExitStatus> {
         }
     })?;
 
-    let exit_status = if watch {
-        main_loop.watch(&mut db)?
-    } else {
-        main_loop.run(&mut db)?
-    };
+    let file_changes_notifier = main_loop.file_changes_notifier();
 
-    tracing::trace!("Counts for entire CLI run:\n{}", countme::get_all());
+    // Watch for file changes and re-trigger the analysis.
+    let mut file_watcher = FileWatcher::new(move |changes| {
+        file_changes_notifier.notify(changes);
+    })?;
 
-    std::mem::forget(db);
+    file_watcher.watch_folder(workspace_folder.as_std_path())?;
 
-    if exit_zero {
-        Ok(ExitStatus::Success)
-    } else {
-        Ok(exit_status)
-    }
-}
+    main_loop.run(&mut program);
 
-#[derive(Copy, Clone)]
-pub enum ExitStatus {
-    /// Checking was successful and there were no errors.
-    Success = 0,
+    println!("{}", countme::get_all());
 
-    /// Checking was successful but there were errors.
-    Failure = 1,
-
-    /// Checking failed.
-    Error = 2,
-}
-
-impl Termination for ExitStatus {
-    fn report(self) -> ExitCode {
-        ExitCode::from(self as u8)
-    }
+    Ok(())
 }
 
 struct MainLoop {
-    /// Sender that can be used to send messages to the main loop.
-    sender: crossbeam_channel::Sender<MainLoopMessage>,
-
-    /// Receiver for the messages sent **to** the main loop.
-    receiver: crossbeam_channel::Receiver<MainLoopMessage>,
-
-    /// The file system watcher, if running in watch mode.
-    watcher: Option<ProjectWatcher>,
-
-    cli_options: Options,
+    orchestrator_sender: crossbeam_channel::Sender<OrchestratorMessage>,
+    main_loop_receiver: crossbeam_channel::Receiver<MainLoopMessage>,
 }
 
 impl MainLoop {
-    fn new(cli_options: Options) -> (Self, MainLoopCancellationToken) {
-        let (sender, receiver) = crossbeam_channel::bounded(10);
+    fn new() -> (Self, MainLoopCancellationToken) {
+        let (orchestrator_sender, orchestrator_receiver) = crossbeam_channel::bounded(1);
+        let (main_loop_sender, main_loop_receiver) = crossbeam_channel::bounded(1);
+
+        let mut orchestrator = Orchestrator {
+            receiver: orchestrator_receiver,
+            sender: main_loop_sender.clone(),
+            revision: 0,
+        };
+
+        std::thread::spawn(move || {
+            orchestrator.run();
+        });
 
         (
             Self {
-                sender: sender.clone(),
-                receiver,
-                watcher: None,
-                cli_options,
+                orchestrator_sender,
+                main_loop_receiver,
+            },
+            MainLoopCancellationToken {
+                sender: main_loop_sender,
             },
-            MainLoopCancellationToken { sender },
         )
     }
 
-    fn watch(mut self, db: &mut ProjectDatabase) -> Result<ExitStatus> {
-        tracing::debug!("Starting watch mode");
-        let sender = self.sender.clone();
-        let watcher = watch::directory_watcher(move |event| {
-            sender.send(MainLoopMessage::ApplyChanges(event)).unwrap();
-        })?;
-
-        self.watcher = Some(ProjectWatcher::new(watcher, db));
-
-        self.run(db)?;
-
-        Ok(ExitStatus::Success)
+    fn file_changes_notifier(&self) -> FileChangesNotifier {
+        FileChangesNotifier {
+            sender: self.orchestrator_sender.clone(),
+        }
     }
 
-    fn run(mut self, db: &mut ProjectDatabase) -> Result<ExitStatus> {
-        self.sender.send(MainLoopMessage::CheckWorkspace).unwrap();
+    #[allow(clippy::print_stderr)]
+    fn run(self, program: &mut Program) {
+        self.orchestrator_sender
+            .send(OrchestratorMessage::Run)
+            .unwrap();
 
-        let result = self.main_loop(db);
+        for message in &self.main_loop_receiver {
+            tracing::trace!("Main Loop: Tick");
 
-        tracing::debug!("Exiting main loop");
-
-        result
-    }
-
-    fn main_loop(&mut self, db: &mut ProjectDatabase) -> Result<ExitStatus> {
-        // Schedule the first check.
-        tracing::debug!("Starting main loop");
-
-        let mut revision = 0u64;
-
-        while let Ok(message) = self.receiver.recv() {
             match message {
-                MainLoopMessage::CheckWorkspace => {
-                    let db = db.clone();
-                    let sender = self.sender.clone();
+                MainLoopMessage::CheckProgram { revision } => {
+                    let program = program.snapshot();
+                    let sender = self.orchestrator_sender.clone();
 
-                    // Spawn a new task that checks the project. This needs to be done in a separate thread
+                    // Spawn a new task that checks the program. This needs to be done in a separate thread
                     // to prevent blocking the main loop here.
                     rayon::spawn(move || {
-                        if let Ok(result) = db.check() {
-                            // Send the result back to the main loop for printing.
+                        if let Ok(result) = program.check() {
                             sender
-                                .send(MainLoopMessage::CheckCompleted { result, revision })
+                                .send(OrchestratorMessage::CheckProgramCompleted {
+                                    diagnostics: result,
+                                    revision,
+                                })
                                 .unwrap();
                         }
                     });
                 }
-
-                MainLoopMessage::CheckCompleted {
-                    result,
-                    revision: check_revision,
-                } => {
-                    let terminal_settings = db.project().settings(db).terminal();
-                    let display_config = DisplayDiagnosticConfig::default()
-                        .format(terminal_settings.output_format)
-                        .color(colored::control::SHOULD_COLORIZE.should_colorize());
-
-                    let min_error_severity = if terminal_settings.error_on_warning {
-                        Severity::Warning
-                    } else {
-                        Severity::Error
-                    };
-
-                    if check_revision == revision {
-                        if db.project().files(db).is_empty() {
-                            tracing::warn!("No python files found under the given path(s)");
-                        }
-
-                        let mut stdout = stdout().lock();
-
-                        if result.is_empty() {
-                            writeln!(stdout, "All checks passed!")?;
-
-                            if self.watcher.is_none() {
-                                return Ok(ExitStatus::Success);
-                            }
-                        } else {
-                            let mut failed = false;
-                            let diagnostics_count = result.len();
-
-                            for diagnostic in result {
-                                write!(stdout, "{}", diagnostic.display(db, &display_config))?;
-
-                                failed |= diagnostic.severity() >= min_error_severity;
-                            }
-
-                            writeln!(
-                                stdout,
-                                "Found {} diagnostic{}",
-                                diagnostics_count,
-                                if diagnostics_count > 1 { "s" } else { "" }
-                            )?;
-
-                            if self.watcher.is_none() {
-                                return Ok(if failed {
-                                    ExitStatus::Failure
-                                } else {
-                                    ExitStatus::Success
-                                });
-                            }
-                        }
-                    } else {
-                        tracing::debug!(
-                            "Discarding check result for outdated revision: current: {revision}, result revision: {check_revision}"
-                        );
-                    }
-
-                    tracing::trace!("Counts after last check:\n{}", countme::get_all());
-                }
-
                 MainLoopMessage::ApplyChanges(changes) => {
-                    revision += 1;
                     // Automatically cancels any pending queries and waits for them to complete.
-                    db.apply_changes(changes, Some(&self.cli_options));
-                    if let Some(watcher) = self.watcher.as_mut() {
-                        watcher.update(db);
-                    }
-                    self.sender.send(MainLoopMessage::CheckWorkspace).unwrap();
+                    program.apply_changes(changes);
+                }
+                MainLoopMessage::CheckCompleted(diagnostics) => {
+                    eprintln!("{}", diagnostics.join("\n"));
+                    eprintln!("{}", countme::get_all());
                 }
                 MainLoopMessage::Exit => {
-                    // Cancel any pending queries and wait for them to complete.
-                    // TODO: Don't use Salsa internal APIs
-                    //  [Zulip-Thread](https://salsa.zulipchat.com/#narrow/stream/333573-salsa-3.2E0/topic/Expose.20an.20API.20to.20cancel.20other.20queries)
-                    let _ = db.zalsa_mut();
-                    return Ok(ExitStatus::Success);
+                    eprintln!("{}", countme::get_all());
+                    return;
                 }
             }
-
-            tracing::debug!("Waiting for next main loop message.");
         }
+    }
+}
 
-        Ok(ExitStatus::Success)
+impl Drop for MainLoop {
+    fn drop(&mut self) {
+        self.orchestrator_sender
+            .send(OrchestratorMessage::Shutdown)
+            .unwrap();
+    }
+}
+
+#[derive(Debug, Clone)]
+struct FileChangesNotifier {
+    sender: crossbeam_channel::Sender<OrchestratorMessage>,
+}
+
+impl FileChangesNotifier {
+    fn notify(&self, changes: Vec<FileWatcherChange>) {
+        self.sender
+            .send(OrchestratorMessage::FileChanges(changes))
+            .unwrap();
     }
 }
 
@@ -353,33 +212,165 @@ impl MainLoopCancellationToken {
     }
 }
 
+struct Orchestrator {
+    /// Sends messages to the main loop.
+    sender: crossbeam_channel::Sender<MainLoopMessage>,
+    /// Receives messages from the main loop.
+    receiver: crossbeam_channel::Receiver<OrchestratorMessage>,
+    revision: usize,
+}
+
+impl Orchestrator {
+    #[allow(clippy::print_stderr)]
+    fn run(&mut self) {
+        while let Ok(message) = self.receiver.recv() {
+            match message {
+                OrchestratorMessage::Run => {
+                    self.sender
+                        .send(MainLoopMessage::CheckProgram {
+                            revision: self.revision,
+                        })
+                        .unwrap();
+                }
+
+                OrchestratorMessage::CheckProgramCompleted {
+                    diagnostics,
+                    revision,
+                } => {
+                    // Only take the diagnostics if they are for the latest revision.
+                    if self.revision == revision {
+                        self.sender
+                            .send(MainLoopMessage::CheckCompleted(diagnostics))
+                            .unwrap();
+                    } else {
+                        tracing::debug!("Discarding diagnostics for outdated revision {revision} (current: {}).", self.revision);
+                    }
+                }
+
+                OrchestratorMessage::FileChanges(changes) => {
+                    // Request cancellation, but wait until all analysis tasks have completed to
+                    // avoid stale messages in the next main loop.
+
+                    self.revision += 1;
+                    self.debounce_changes(changes);
+                }
+                OrchestratorMessage::Shutdown => {
+                    return self.shutdown();
+                }
+            }
+        }
+    }
+
+    fn debounce_changes(&self, mut changes: Vec<FileWatcherChange>) {
+        loop {
+            // Consume possibly incoming file change messages before running a new analysis, but don't wait for more than 100ms.
+            crossbeam_channel::select! {
+                recv(self.receiver) -> message => {
+                    match message {
+                        Ok(OrchestratorMessage::Shutdown) => {
+                            return self.shutdown();
+                        }
+                        Ok(OrchestratorMessage::FileChanges(file_changes)) => {
+                            changes.extend(file_changes);
+                        }
+
+                        Ok(OrchestratorMessage::CheckProgramCompleted { .. })=> {
+                            // disregard any outdated completion message.
+                        }
+                        Ok(OrchestratorMessage::Run) => unreachable!("The orchestrator is already running."),
+
+                        Err(_) => {
+                            // There are no more senders, no point in waiting for more messages
+                            return;
+                        }
+                    }
+                },
+                default(std::time::Duration::from_millis(10)) => {
+                    // No more file changes after 10 ms, send the changes and schedule a new analysis
+                    self.sender.send(MainLoopMessage::ApplyChanges(changes)).unwrap();
+                    self.sender.send(MainLoopMessage::CheckProgram { revision: self.revision}).unwrap();
+                    return;
+                }
+            }
+        }
+    }
+
+    #[allow(clippy::unused_self)]
+    fn shutdown(&self) {
+        tracing::trace!("Shutting down orchestrator.");
+    }
+}
+
 /// Message sent from the orchestrator to the main loop.
 #[derive(Debug)]
 enum MainLoopMessage {
-    CheckWorkspace,
-    CheckCompleted {
-        /// The diagnostics that were found during the check.
-        result: Vec<Diagnostic>,
-        revision: u64,
-    },
-    ApplyChanges(Vec<watch::ChangeEvent>),
+    CheckProgram { revision: usize },
+    CheckCompleted(Vec<String>),
+    ApplyChanges(Vec<FileWatcherChange>),
     Exit,
 }
 
-fn set_colored_override(color: Option<TerminalColor>) {
-    let Some(color) = color else {
-        return;
-    };
+#[derive(Debug)]
+enum OrchestratorMessage {
+    Run,
+    Shutdown,
 
-    match color {
-        TerminalColor::Auto => {
-            colored::control::unset_override();
-        }
-        TerminalColor::Always => {
-            colored::control::set_override(true);
-        }
-        TerminalColor::Never => {
-            colored::control::set_override(false);
-        }
+    CheckProgramCompleted {
+        diagnostics: Vec<String>,
+        revision: usize,
+    },
+
+    FileChanges(Vec<FileWatcherChange>),
+}
+
+fn setup_tracing() {
+    let subscriber = Registry::default().with(
+        tracing_tree::HierarchicalLayer::default()
+            .with_indent_lines(true)
+            .with_indent_amount(2)
+            .with_bracketed_fields(true)
+            .with_thread_ids(true)
+            .with_targets(true)
+            .with_writer(|| Box::new(std::io::stderr()))
+            .with_timer(Uptime::default())
+            .with_filter(LoggingFilter {
+                trace_level: Level::TRACE,
+            }),
+    );
+
+    tracing::subscriber::set_global_default(subscriber).unwrap();
+}
+
+struct LoggingFilter {
+    trace_level: Level,
+}
+
+impl LoggingFilter {
+    fn is_enabled(&self, meta: &Metadata<'_>) -> bool {
+        let filter = if meta.target().starts_with("red_knot") || meta.target().starts_with("ruff") {
+            self.trace_level
+        } else {
+            Level::INFO
+        };
+
+        meta.level() <= &filter
+    }
+}
+
+impl<S> Filter<S> for LoggingFilter {
+    fn enabled(&self, meta: &Metadata<'_>, _cx: &Context<'_, S>) -> bool {
+        self.is_enabled(meta)
+    }
+
+    fn callsite_enabled(&self, meta: &'static Metadata<'static>) -> Interest {
+        if self.is_enabled(meta) {
+            Interest::always()
+        } else {
+            Interest::never()
+        }
+    }
+
+    fn max_level_hint(&self) -> Option<LevelFilter> {
+        Some(LevelFilter::from_level(self.trace_level))
     }
 }

crates/red_knot/src/program/check.rs

@@ -0,0 +1,32 @@
+use ruff_db::vfs::VfsFile;
+use salsa::Cancelled;
+
+use crate::lint::{lint_semantic, lint_syntax, Diagnostics};
+use crate::program::Program;
+
+impl Program {
+    /// Checks all open files in the workspace and its dependencies.
+    #[tracing::instrument(level = "debug", skip_all)]
+    pub fn check(&self) -> Result<Vec<String>, Cancelled> {
+        self.with_db(|db| {
+            let mut result = Vec::new();
+            for open_file in db.workspace.open_files() {
+                result.extend_from_slice(&db.check_file_impl(open_file));
+            }
+
+            result
+        })
+    }
+
+    #[tracing::instrument(level = "debug", skip(self))]
+    pub fn check_file(&self, file: VfsFile) -> Result<Diagnostics, Cancelled> {
+        self.with_db(|db| db.check_file_impl(file))
+    }
+
+    fn check_file_impl(&self, file: VfsFile) -> Diagnostics {
+        let mut diagnostics = Vec::new();
+        diagnostics.extend_from_slice(lint_syntax(self, file));
+        diagnostics.extend_from_slice(lint_semantic(self, file));
+        Diagnostics::from(diagnostics)
+    }
+}

crates/red_knot/src/program/mod.rs

@@ -0,0 +1,131 @@
+use std::panic::{RefUnwindSafe, UnwindSafe};
+use std::sync::Arc;
+
+use salsa::{Cancelled, Database};
+
+use red_knot_module_resolver::{Db as ResolverDb, Jar as ResolverJar};
+use red_knot_python_semantic::{Db as SemanticDb, Jar as SemanticJar};
+use ruff_db::file_system::{FileSystem, FileSystemPathBuf};
+use ruff_db::vfs::{Vfs, VfsFile, VfsPath};
+use ruff_db::{Db as SourceDb, Jar as SourceJar, Upcast};
+
+use crate::db::{Db, Jar};
+use crate::Workspace;
+
+mod check;
+
+#[salsa::db(SourceJar, ResolverJar, SemanticJar, Jar)]
+pub struct Program {
+    storage: salsa::Storage<Program>,
+    vfs: Vfs,
+    fs: Arc<dyn FileSystem + Send + Sync + RefUnwindSafe>,
+    workspace: Workspace,
+}
+
+impl Program {
+    pub fn new<Fs>(workspace: Workspace, file_system: Fs) -> Self
+    where
+        Fs: FileSystem + 'static + Send + Sync + RefUnwindSafe,
+    {
+        Self {
+            storage: salsa::Storage::default(),
+            vfs: Vfs::default(),
+            fs: Arc::new(file_system),
+            workspace,
+        }
+    }
+
+    pub fn apply_changes<I>(&mut self, changes: I)
+    where
+        I: IntoIterator<Item = FileWatcherChange>,
+    {
+        for change in changes {
+            VfsFile::touch_path(self, &VfsPath::file_system(change.path));
+        }
+    }
+
+    pub fn workspace(&self) -> &Workspace {
+        &self.workspace
+    }
+
+    pub fn workspace_mut(&mut self) -> &mut Workspace {
+        &mut self.workspace
+    }
+
+    #[allow(clippy::unnecessary_wraps)]
+    fn with_db<F, T>(&self, f: F) -> Result<T, Cancelled>
+    where
+        F: FnOnce(&Program) -> T + UnwindSafe,
+    {
+        // TODO: Catch in `Caancelled::catch`
+        //  See https://salsa.zulipchat.com/#narrow/stream/145099-general/topic/How.20to.20use.20.60Cancelled.3A.3Acatch.60
+        Ok(f(self))
+    }
+}
+
+impl Upcast<dyn SemanticDb> for Program {
+    fn upcast(&self) -> &(dyn SemanticDb + 'static) {
+        self
+    }
+}
+
+impl Upcast<dyn SourceDb> for Program {
+    fn upcast(&self) -> &(dyn SourceDb + 'static) {
+        self
+    }
+}
+
+impl Upcast<dyn ResolverDb> for Program {
+    fn upcast(&self) -> &(dyn ResolverDb + 'static) {
+        self
+    }
+}
+
+impl ResolverDb for Program {}
+
+impl SemanticDb for Program {}
+
+impl SourceDb for Program {
+    fn file_system(&self) -> &dyn FileSystem {
+        &*self.fs
+    }
+
+    fn vfs(&self) -> &Vfs {
+        &self.vfs
+    }
+}
+
+impl Database for Program {}
+
+impl Db for Program {}
+
+impl salsa::ParallelDatabase for Program {
+    fn snapshot(&self) -> salsa::Snapshot<Self> {
+        salsa::Snapshot::new(Self {
+            storage: self.storage.snapshot(),
+            vfs: self.vfs.snapshot(),
+            fs: self.fs.clone(),
+            workspace: self.workspace.clone(),
+        })
+    }
+}
+
+#[derive(Clone, Debug)]
+pub struct FileWatcherChange {
+    path: FileSystemPathBuf,
+    #[allow(unused)]
+    kind: FileChangeKind,
+}
+
+impl FileWatcherChange {
+    pub fn new(path: FileSystemPathBuf, kind: FileChangeKind) -> Self {
+        Self { path, kind }
+    }
+}
+
+#[derive(Copy, Clone, Debug, Eq, PartialEq)]
+pub enum FileChangeKind {
+    Created,
+    Modified,
+    Deleted,
+}

crates/red_knot/src/python_version.rs

@@ -1,60 +0,0 @@
-/// Enumeration of all supported Python versions
-///
-/// TODO: unify with the `PythonVersion` enum in the linter/formatter crates?
-#[derive(Copy, Clone, Hash, Debug, PartialEq, Eq, PartialOrd, Ord, Default, clap::ValueEnum)]
-pub enum PythonVersion {
-    #[default]
-    #[value(name = "3.9")]
-    Py39,
-    #[value(name = "3.10")]
-    Py310,
-    #[value(name = "3.11")]
-    Py311,
-    #[value(name = "3.12")]
-    Py312,
-    #[value(name = "3.13")]
-    Py313,
-}
-
-impl PythonVersion {
-    const fn as_str(self) -> &'static str {
-        match self {
-            Self::Py39 => "3.9",
-            Self::Py310 => "3.10",
-            Self::Py311 => "3.11",
-            Self::Py312 => "3.12",
-            Self::Py313 => "3.13",
-        }
-    }
-}
-
-impl std::fmt::Display for PythonVersion {
-    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-        f.write_str(self.as_str())
-    }
-}
-
-impl From<PythonVersion> for ruff_python_ast::PythonVersion {
-    fn from(value: PythonVersion) -> Self {
-        match value {
-            PythonVersion::Py39 => Self::PY39,
-            PythonVersion::Py310 => Self::PY310,
-            PythonVersion::Py311 => Self::PY311,
-            PythonVersion::Py312 => Self::PY312,
-            PythonVersion::Py313 => Self::PY313,
-        }
-    }
-}
-
-#[cfg(test)]
-mod tests {
-    use crate::python_version::PythonVersion;
-
-    #[test]
-    fn same_default_as_python_version() {
-        assert_eq!(
-            ruff_python_ast::PythonVersion::from(PythonVersion::default()),
-            ruff_python_ast::PythonVersion::default()
-        );
-    }
-}

crates/red_knot/src/version.rs

@@ -1,105 +0,0 @@
-//! Code for representing Red Knot's release version number.
-use std::fmt;
-
-/// Information about the git repository where Red Knot was built from.
-pub(crate) struct CommitInfo {
-    short_commit_hash: String,
-    commit_date: String,
-    commits_since_last_tag: u32,
-}
-
-/// Red Knot's version.
-pub(crate) struct VersionInfo {
-    /// Red Knot's version, such as "0.5.1"
-    version: String,
-    /// Information about the git commit we may have been built from.
-    ///
-    /// `None` if not built from a git repo or if retrieval failed.
-    commit_info: Option<CommitInfo>,
-}
-
-impl fmt::Display for VersionInfo {
-    /// Formatted version information: `<version>[+<commits>] (<commit> <date>)`
-    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        write!(f, "{}", self.version)?;
-
-        if let Some(ref ci) = self.commit_info {
-            if ci.commits_since_last_tag > 0 {
-                write!(f, "+{}", ci.commits_since_last_tag)?;
-            }
-            write!(f, " ({} {})", ci.short_commit_hash, ci.commit_date)?;
-        }
-
-        Ok(())
-    }
-}
-
-/// Returns information about Red Knot's version.
-pub(crate) fn version() -> VersionInfo {
-    // Environment variables are only read at compile-time
-    macro_rules! option_env_str {
-        ($name:expr) => {
-            option_env!($name).map(|s| s.to_string())
-        };
-    }
-
-    // This version is pulled from Cargo.toml and set by Cargo
-    let version = option_env_str!("CARGO_PKG_VERSION").unwrap();
-
-    // Commit info is pulled from git and set by `build.rs`
-    let commit_info =
-        option_env_str!("RED_KNOT_COMMIT_SHORT_HASH").map(|short_commit_hash| CommitInfo {
-            short_commit_hash,
-            commit_date: option_env_str!("RED_KNOT_COMMIT_DATE").unwrap(),
-            commits_since_last_tag: option_env_str!("RED_KNOT_LAST_TAG_DISTANCE")
-                .as_deref()
-                .map_or(0, |value| value.parse::<u32>().unwrap_or(0)),
-        });
-
-    VersionInfo {
-        version,
-        commit_info,
-    }
-}
-
-#[cfg(test)]
-mod tests {
-    use insta::assert_snapshot;
-
-    use super::{CommitInfo, VersionInfo};
-
-    #[test]
-    fn version_formatting() {
-        let version = VersionInfo {
-            version: "0.0.0".to_string(),
-            commit_info: None,
-        };
-        assert_snapshot!(version, @"0.0.0");
-    }
-
-    #[test]
-    fn version_formatting_with_commit_info() {
-        let version = VersionInfo {
-            version: "0.0.0".to_string(),
-            commit_info: Some(CommitInfo {
-                short_commit_hash: "53b0f5d92".to_string(),
-                commit_date: "2023-10-19".to_string(),
-                commits_since_last_tag: 0,
-            }),
-        };
-        assert_snapshot!(version, @"0.0.0 (53b0f5d92 2023-10-19)");
-    }
-
-    #[test]
-    fn version_formatting_with_commits_since_last_tag() {
-        let version = VersionInfo {
-            version: "0.0.0".to_string(),
-            commit_info: Some(CommitInfo {
-                short_commit_hash: "53b0f5d92".to_string(),
-                commit_date: "2023-10-19".to_string(),
-                commits_since_last_tag: 24,
-            }),
-        };
-        assert_snapshot!(version, @"0.0.0+24 (53b0f5d92 2023-10-19)");
-    }
-}

crates/red_knot/src/watch.rs

@@ -0,0 +1,82 @@
+use std::path::Path;
+
+use crate::program::{FileChangeKind, FileWatcherChange};
+use anyhow::Context;
+use notify::event::{CreateKind, RemoveKind};
+use notify::{recommended_watcher, Event, EventKind, RecommendedWatcher, RecursiveMode, Watcher};
+use ruff_db::file_system::FileSystemPath;
+
+pub struct FileWatcher {
+    watcher: RecommendedWatcher,
+}
+
+pub trait EventHandler: Send + 'static {
+    fn handle(&self, changes: Vec<FileWatcherChange>);
+}
+
+impl<F> EventHandler for F
+where
+    F: Fn(Vec<FileWatcherChange>) + Send + 'static,
+{
+    fn handle(&self, changes: Vec<FileWatcherChange>) {
+        let f = self;
+        f(changes);
+    }
+}
+
+impl FileWatcher {
+    pub fn new<E>(handler: E) -> anyhow::Result<Self>
+    where
+        E: EventHandler,
+    {
+        Self::from_handler(Box::new(handler))
+    }
+
+    fn from_handler(handler: Box<dyn EventHandler>) -> anyhow::Result<Self> {
+        let watcher = recommended_watcher(move |changes: notify::Result<Event>| {
+            match changes {
+                Ok(event) => {
+                    // TODO verify that this handles all events correctly
+                    let change_kind = match event.kind {
+                        EventKind::Create(CreateKind::File) => FileChangeKind::Created,
+                        EventKind::Modify(_) => FileChangeKind::Modified,
+                        EventKind::Remove(RemoveKind::File) => FileChangeKind::Deleted,
+                        _ => {
+                            return;
+                        }
+                    };
+
+                    let mut changes = Vec::new();
+
+                    for path in event.paths {
+                        if path.is_file() {
+                            if let Some(fs_path) = FileSystemPath::from_std_path(&path) {
+                                changes.push(FileWatcherChange::new(
+                                    fs_path.to_path_buf(),
+                                    change_kind,
+                                ));
+                            }
+                        }
+                    }
+
+                    if !changes.is_empty() {
+                        handler.handle(changes);
+                    }
+                }
+                // TODO proper error handling
+                Err(err) => {
+                    panic!("Error: {err}");
+                }
+            }
+        })
+        .context("Failed to create file watcher.")?;
+
+        Ok(Self { watcher })
+    }
+
+    pub fn watch_folder(&mut self, path: &Path) -> anyhow::Result<()> {
+        self.watcher.watch(path, RecursiveMode::Recursive)?;
+
+        Ok(())
+    }
+}

crates/red_knot_ide/Cargo.toml

@@ -1,31 +0,0 @@
-[package]
-name = "red_knot_ide"
-version = "0.0.0"
-publish = false
-authors = { workspace = true }
-edition = { workspace = true }
-rust-version = { workspace = true }
-homepage = { workspace = true }
-documentation = { workspace = true }
-repository = { workspace = true }
-license = { workspace = true }
-
-[dependencies]
-ruff_db = { workspace = true }
-ruff_python_ast = { workspace = true }
-ruff_python_parser = { workspace = true }
-ruff_text_size = { workspace = true }
-red_knot_python_semantic = { workspace = true }
-
-rustc-hash = { workspace = true }
-salsa = { workspace = true }
-smallvec = { workspace = true }
-tracing = { workspace = true }
-
-[dev-dependencies]
-red_knot_vendored = { workspace = true }
-
-insta = { workspace = true, features = ["filters"] }
-
-[lints]
-workspace = true

crates/red_knot_ide/src/db.rs

@@ -1,134 +0,0 @@
-use red_knot_python_semantic::Db as SemanticDb;
-use ruff_db::{Db as SourceDb, Upcast};
-
-#[salsa::db]
-pub trait Db: SemanticDb + Upcast<dyn SemanticDb> + Upcast<dyn SourceDb> {}
-
-#[cfg(test)]
-pub(crate) mod tests {
-    use std::sync::Arc;
-
-    use super::Db;
-    use red_knot_python_semantic::lint::{LintRegistry, RuleSelection};
-    use red_knot_python_semantic::{default_lint_registry, Db as SemanticDb};
-    use ruff_db::files::{File, Files};
-    use ruff_db::system::{DbWithTestSystem, System, TestSystem};
-    use ruff_db::vendored::VendoredFileSystem;
-    use ruff_db::{Db as SourceDb, Upcast};
-
-    #[salsa::db]
-    #[derive(Clone)]
-    pub(crate) struct TestDb {
-        storage: salsa::Storage<Self>,
-        files: Files,
-        system: TestSystem,
-        vendored: VendoredFileSystem,
-        events: Arc<std::sync::Mutex<Vec<salsa::Event>>>,
-        rule_selection: Arc<RuleSelection>,
-    }
-
-    #[allow(dead_code)]
-    impl TestDb {
-        pub(crate) fn new() -> Self {
-            Self {
-                storage: salsa::Storage::default(),
-                system: TestSystem::default(),
-                vendored: red_knot_vendored::file_system().clone(),
-                events: Arc::default(),
-                files: Files::default(),
-                rule_selection: Arc::new(RuleSelection::from_registry(default_lint_registry())),
-            }
-        }
-
-        /// Takes the salsa events.
-        ///
-        /// ## Panics
-        /// If there are any pending salsa snapshots.
-        pub(crate) fn take_salsa_events(&mut self) -> Vec<salsa::Event> {
-            let inner = Arc::get_mut(&mut self.events).expect("no pending salsa snapshots");
-
-            let events = inner.get_mut().unwrap();
-            std::mem::take(&mut *events)
-        }
-
-        /// Clears the salsa events.
-        ///
-        /// ## Panics
-        /// If there are any pending salsa snapshots.
-        pub(crate) fn clear_salsa_events(&mut self) {
-            self.take_salsa_events();
-        }
-    }
-
-    impl DbWithTestSystem for TestDb {
-        fn test_system(&self) -> &TestSystem {
-            &self.system
-        }
-
-        fn test_system_mut(&mut self) -> &mut TestSystem {
-            &mut self.system
-        }
-    }
-
-    #[salsa::db]
-    impl SourceDb for TestDb {
-        fn vendored(&self) -> &VendoredFileSystem {
-            &self.vendored
-        }
-
-        fn system(&self) -> &dyn System {
-            &self.system
-        }
-
-        fn files(&self) -> &Files {
-            &self.files
-        }
-    }
-
-    impl Upcast<dyn SourceDb> for TestDb {
-        fn upcast(&self) -> &(dyn SourceDb + 'static) {
-            self
-        }
-        fn upcast_mut(&mut self) -> &mut (dyn SourceDb + 'static) {
-            self
-        }
-    }
-
-    impl Upcast<dyn SemanticDb> for TestDb {
-        fn upcast(&self) -> &(dyn SemanticDb + 'static) {
-            self
-        }
-
-        fn upcast_mut(&mut self) -> &mut dyn SemanticDb {
-            self
-        }
-    }
-
-    #[salsa::db]
-    impl SemanticDb for TestDb {
-        fn is_file_open(&self, file: File) -> bool {
-            !file.path(self).is_vendored_path()
-        }
-
-        fn rule_selection(&self) -> Arc<RuleSelection> {
-            self.rule_selection.clone()
-        }
-
-        fn lint_registry(&self) -> &LintRegistry {
-            default_lint_registry()
-        }
-    }
-
-    #[salsa::db]
-    impl Db for TestDb {}
-
-    #[salsa::db]
-    impl salsa::Database for TestDb {
-        fn salsa_event(&self, event: &dyn Fn() -> salsa::Event) {
-            let event = event();
-            tracing::trace!("event: {event:?}");
-            let mut events = self.events.lock().unwrap();
-            events.push(event);
-        }
-    }
-}

crates/red_knot_ide/src/find_node.rs

@@ -1,106 +0,0 @@
-use ruff_python_ast::visitor::source_order::{SourceOrderVisitor, TraversalSignal};
-use ruff_python_ast::AnyNodeRef;
-use ruff_text_size::{Ranged, TextRange};
-use std::fmt;
-use std::fmt::Formatter;
-
-/// Returns the node with a minimal range that fully contains `range`.
-///
-/// If `range` is empty and falls within a parser *synthesized* node generated during error recovery,
-/// then the first node with the given range is returned.
-///
-/// ## Panics
-/// Panics if `range` is not contained within `root`.
-pub(crate) fn covering_node(root: AnyNodeRef, range: TextRange) -> CoveringNode {
-    struct Visitor<'a> {
-        range: TextRange,
-        found: bool,
-        ancestors: Vec<AnyNodeRef<'a>>,
-    }
-
-    impl<'a> SourceOrderVisitor<'a> for Visitor<'a> {
-        fn enter_node(&mut self, node: AnyNodeRef<'a>) -> TraversalSignal {
-            // If the node fully contains the range, than it is a possible match but traverse into its children
-            // to see if there's a node with a narrower range.
-            if !self.found && node.range().contains_range(self.range) {
-                self.ancestors.push(node);
-                TraversalSignal::Traverse
-            } else {
-                TraversalSignal::Skip
-            }
-        }
-
-        fn leave_node(&mut self, node: AnyNodeRef<'a>) {
-            if !self.found && self.ancestors.last() == Some(&node) {
-                self.found = true;
-            }
-        }
-    }
-
-    assert!(
-        root.range().contains_range(range),
-        "Range is not contained within root"
-    );
-
-    let mut visitor = Visitor {
-        range,
-        found: false,
-        ancestors: Vec::new(),
-    };
-
-    root.visit_source_order(&mut visitor);
-
-    let minimal = visitor.ancestors.pop().unwrap_or(root);
-    CoveringNode {
-        node: minimal,
-        ancestors: visitor.ancestors,
-    }
-}
-
-/// The node with a minimal range that fully contains the search range.
-pub(crate) struct CoveringNode<'a> {
-    /// The node with a minimal range that fully contains the search range.
-    node: AnyNodeRef<'a>,
-
-    /// The node's ancestor (the spine up to the root).
-    ancestors: Vec<AnyNodeRef<'a>>,
-}
-
-impl<'a> CoveringNode<'a> {
-    pub(crate) fn node(&self) -> AnyNodeRef<'a> {
-        self.node
-    }
-
-    /// Returns the node's parent.
-    pub(crate) fn parent(&self) -> Option<AnyNodeRef<'a>> {
-        self.ancestors.last().copied()
-    }
-
-    /// Finds the minimal node that fully covers the range and fulfills the given predicate.
-    pub(crate) fn find(mut self, f: impl Fn(AnyNodeRef<'a>) -> bool) -> Result<Self, Self> {
-        if f(self.node) {
-            return Ok(self);
-        }
-
-        match self.ancestors.iter().rposition(|node| f(*node)) {
-            Some(index) => {
-                let node = self.ancestors[index];
-                self.ancestors.truncate(index);
-
-                Ok(Self {
-                    node,
-                    ancestors: self.ancestors,
-                })
-            }
-            None => Err(self),
-        }
-    }
-}
-
-impl fmt::Debug for CoveringNode<'_> {
-    fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
-        f.debug_tuple("NodeWithAncestors")
-            .field(&self.node)
-            .finish()
-    }
-}

crates/red_knot_ide/src/goto.rs

@@ -1,851 +0,0 @@
-use crate::find_node::covering_node;
-use crate::{Db, HasNavigationTargets, NavigationTargets, RangedValue};
-use red_knot_python_semantic::types::Type;
-use red_knot_python_semantic::{HasType, SemanticModel};
-use ruff_db::files::{File, FileRange};
-use ruff_db::parsed::{parsed_module, ParsedModule};
-use ruff_python_ast::{self as ast, AnyNodeRef};
-use ruff_python_parser::TokenKind;
-use ruff_text_size::{Ranged, TextRange, TextSize};
-
-pub fn goto_type_definition(
-    db: &dyn Db,
-    file: File,
-    offset: TextSize,
-) -> Option<RangedValue<NavigationTargets>> {
-    let parsed = parsed_module(db.upcast(), file);
-    let goto_target = find_goto_target(parsed, offset)?;
-
-    let model = SemanticModel::new(db.upcast(), file);
-    let ty = goto_target.inferred_type(&model)?;
-
-    tracing::debug!(
-        "Inferred type of covering node is {}",
-        ty.display(db.upcast())
-    );
-
-    let navigation_targets = ty.navigation_targets(db);
-
-    Some(RangedValue {
-        range: FileRange::new(file, goto_target.range()),
-        value: navigation_targets,
-    })
-}
-
-#[derive(Clone, Copy, Debug)]
-pub(crate) enum GotoTarget<'a> {
-    Expression(ast::ExprRef<'a>),
-    FunctionDef(&'a ast::StmtFunctionDef),
-    ClassDef(&'a ast::StmtClassDef),
-    Parameter(&'a ast::Parameter),
-    Alias(&'a ast::Alias),
-
-    /// Go to on the module name of an import from
-    /// ```py
-    /// from foo import bar
-    ///      ^^^
-    /// ```
-    ImportedModule(&'a ast::StmtImportFrom),
-
-    /// Go to on the exception handler variable
-    /// ```py
-    /// try: ...
-    /// except Exception as e: ...
-    ///                     ^
-    /// ```
-    ExceptVariable(&'a ast::ExceptHandlerExceptHandler),
-
-    /// Go to on a keyword argument
-    /// ```py
-    /// test(a = 1)
-    ///      ^
-    /// ```
-    KeywordArgument(&'a ast::Keyword),
-
-    /// Go to on the rest parameter of a pattern match
-    ///
-    /// ```py
-    /// match x:
-    ///     case {"a": a, "b": b, **rest}: ...
-    ///                             ^^^^
-    /// ```
-    PatternMatchRest(&'a ast::PatternMatchMapping),
-
-    /// Go to on a keyword argument of a class pattern
-    ///
-    /// ```py
-    /// match Point3D(0, 0, 0):
-    ///     case Point3D(x=0, y=0, z=0): ...
-    ///                  ^    ^    ^
-    /// ```
-    PatternKeywordArgument(&'a ast::PatternKeyword),
-
-    /// Go to on a pattern star argument
-    ///
-    /// ```py
-    /// match array:
-    ///     case [*args]: ...
-    ///            ^^^^
-    PatternMatchStarName(&'a ast::PatternMatchStar),
-
-    /// Go to on the name of a pattern match as pattern
-    ///
-    /// ```py
-    /// match x:
-    ///     case [x] as y: ...
-    ///                 ^
-    PatternMatchAsName(&'a ast::PatternMatchAs),
-
-    /// Go to on the name of a type variable
-    ///
-    /// ```py
-    /// type Alias[T: int = bool] = list[T]
-    ///            ^
-    /// ```
-    TypeParamTypeVarName(&'a ast::TypeParamTypeVar),
-
-    /// Go to on the name of a type param spec
-    ///
-    /// ```py
-    /// type Alias[**P = [int, str]] = Callable[P, int]
-    ///              ^
-    /// ```
-    TypeParamParamSpecName(&'a ast::TypeParamParamSpec),
-
-    /// Go to on the name of a type var tuple
-    ///
-    /// ```py
-    /// type Alias[*Ts = ()] = tuple[*Ts]
-    ///             ^^
-    /// ```
-    TypeParamTypeVarTupleName(&'a ast::TypeParamTypeVarTuple),
-
-    NonLocal {
-        identifier: &'a ast::Identifier,
-    },
-    Globals {
-        identifier: &'a ast::Identifier,
-    },
-}
-
-impl<'db> GotoTarget<'db> {
-    pub(crate) fn inferred_type(self, model: &SemanticModel<'db>) -> Option<Type<'db>> {
-        let ty = match self {
-            GotoTarget::Expression(expression) => expression.inferred_type(model),
-            GotoTarget::FunctionDef(function) => function.inferred_type(model),
-            GotoTarget::ClassDef(class) => class.inferred_type(model),
-            GotoTarget::Parameter(parameter) => parameter.inferred_type(model),
-            GotoTarget::Alias(alias) => alias.inferred_type(model),
-            GotoTarget::ExceptVariable(except) => except.inferred_type(model),
-            GotoTarget::KeywordArgument(argument) => {
-                // TODO: Pyright resolves the declared type of the matching parameter. This seems more accurate
-                // than using the inferred value.
-                argument.value.inferred_type(model)
-            }
-            // TODO: Support identifier targets
-            GotoTarget::PatternMatchRest(_)
-            | GotoTarget::PatternKeywordArgument(_)
-            | GotoTarget::PatternMatchStarName(_)
-            | GotoTarget::PatternMatchAsName(_)
-            | GotoTarget::ImportedModule(_)
-            | GotoTarget::TypeParamTypeVarName(_)
-            | GotoTarget::TypeParamParamSpecName(_)
-            | GotoTarget::TypeParamTypeVarTupleName(_)
-            | GotoTarget::NonLocal { .. }
-            | GotoTarget::Globals { .. } => return None,
-        };
-
-        Some(ty)
-    }
-}
-
-impl Ranged for GotoTarget<'_> {
-    fn range(&self) -> TextRange {
-        match self {
-            GotoTarget::Expression(expression) => expression.range(),
-            GotoTarget::FunctionDef(function) => function.name.range,
-            GotoTarget::ClassDef(class) => class.name.range,
-            GotoTarget::Parameter(parameter) => parameter.name.range,
-            GotoTarget::Alias(alias) => alias.name.range,
-            GotoTarget::ImportedModule(module) => module.module.as_ref().unwrap().range,
-            GotoTarget::ExceptVariable(except) => except.name.as_ref().unwrap().range,
-            GotoTarget::KeywordArgument(keyword) => keyword.arg.as_ref().unwrap().range,
-            GotoTarget::PatternMatchRest(rest) => rest.rest.as_ref().unwrap().range,
-            GotoTarget::PatternKeywordArgument(keyword) => keyword.attr.range,
-            GotoTarget::PatternMatchStarName(star) => star.name.as_ref().unwrap().range,
-            GotoTarget::PatternMatchAsName(as_name) => as_name.name.as_ref().unwrap().range,
-            GotoTarget::TypeParamTypeVarName(type_var) => type_var.name.range,
-            GotoTarget::TypeParamParamSpecName(spec) => spec.name.range,
-            GotoTarget::TypeParamTypeVarTupleName(tuple) => tuple.name.range,
-            GotoTarget::NonLocal { identifier, .. } => identifier.range,
-            GotoTarget::Globals { identifier, .. } => identifier.range,
-        }
-    }
-}
-
-pub(crate) fn find_goto_target(parsed: &ParsedModule, offset: TextSize) -> Option<GotoTarget> {
-    let token = parsed
-        .tokens()
-        .at_offset(offset)
-        .max_by_key(|token| match token.kind() {
-            TokenKind::Name
-            | TokenKind::String
-            | TokenKind::Complex
-            | TokenKind::Float
-            | TokenKind::Int => 1,
-            _ => 0,
-        })?;
-
-    let covering_node = covering_node(parsed.syntax().into(), token.range())
-        .find(|node| node.is_identifier() || node.is_expression())
-        .ok()?;
-
-    tracing::trace!("Covering node is of kind {:?}", covering_node.node().kind());
-
-    match covering_node.node() {
-        AnyNodeRef::Identifier(identifier) => match covering_node.parent() {
-            Some(AnyNodeRef::StmtFunctionDef(function)) => Some(GotoTarget::FunctionDef(function)),
-            Some(AnyNodeRef::StmtClassDef(class)) => Some(GotoTarget::ClassDef(class)),
-            Some(AnyNodeRef::Parameter(parameter)) => Some(GotoTarget::Parameter(parameter)),
-            Some(AnyNodeRef::Alias(alias)) => Some(GotoTarget::Alias(alias)),
-            Some(AnyNodeRef::StmtImportFrom(from)) => Some(GotoTarget::ImportedModule(from)),
-            Some(AnyNodeRef::ExceptHandlerExceptHandler(handler)) => {
-                Some(GotoTarget::ExceptVariable(handler))
-            }
-            Some(AnyNodeRef::Keyword(keyword)) => Some(GotoTarget::KeywordArgument(keyword)),
-            Some(AnyNodeRef::PatternMatchMapping(mapping)) => {
-                Some(GotoTarget::PatternMatchRest(mapping))
-            }
-            Some(AnyNodeRef::PatternKeyword(keyword)) => {
-                Some(GotoTarget::PatternKeywordArgument(keyword))
-            }
-            Some(AnyNodeRef::PatternMatchStar(star)) => {
-                Some(GotoTarget::PatternMatchStarName(star))
-            }
-            Some(AnyNodeRef::PatternMatchAs(as_pattern)) => {
-                Some(GotoTarget::PatternMatchAsName(as_pattern))
-            }
-            Some(AnyNodeRef::TypeParamTypeVar(var)) => Some(GotoTarget::TypeParamTypeVarName(var)),
-            Some(AnyNodeRef::TypeParamParamSpec(bound)) => {
-                Some(GotoTarget::TypeParamParamSpecName(bound))
-            }
-            Some(AnyNodeRef::TypeParamTypeVarTuple(var_tuple)) => {
-                Some(GotoTarget::TypeParamTypeVarTupleName(var_tuple))
-            }
-            Some(AnyNodeRef::ExprAttribute(attribute)) => {
-                Some(GotoTarget::Expression(attribute.into()))
-            }
-            Some(AnyNodeRef::StmtNonlocal(_)) => Some(GotoTarget::NonLocal { identifier }),
-            Some(AnyNodeRef::StmtGlobal(_)) => Some(GotoTarget::Globals { identifier }),
-            None => None,
-            Some(parent) => {
-                tracing::debug!(
-                    "Missing `GoToTarget` for identifier with parent {:?}",
-                    parent.kind()
-                );
-                None
-            }
-        },
-
-        node => node.as_expr_ref().map(GotoTarget::Expression),
-    }
-}
-
-#[cfg(test)]
-mod tests {
-    use crate::tests::{cursor_test, CursorTest, IntoDiagnostic};
-    use crate::{goto_type_definition, NavigationTarget};
-    use insta::assert_snapshot;
-    use ruff_db::diagnostic::{
-        Annotation, Diagnostic, DiagnosticId, LintName, Severity, Span, SubDiagnostic,
-    };
-    use ruff_db::files::FileRange;
-    use ruff_text_size::Ranged;
-
-    #[test]
-    fn goto_type_of_expression_with_class_type() {
-        let test = cursor_test(
-            r#"
-            class Test: ...
-
-            a<CURSOR>b = Test()
-            "#,
-        );
-
-        assert_snapshot!(test.goto_type_definition(), @r###"
-        info: lint:goto-type-definition: Type definition
-         --> /main.py:2:19
-          |
-        2 |             class Test: ...
-          |                   ^^^^
-        3 |
-        4 |             ab = Test()
-          |
-        info: Source
-         --> /main.py:4:13
-          |
-        2 |             class Test: ...
-        3 |
-        4 |             ab = Test()
-          |             ^^
-          |
-        "###);
-    }
-
-    #[test]
-    fn goto_type_of_expression_with_function_type() {
-        let test = cursor_test(
-            r#"
-            def foo(a, b): ...
-
-            ab = foo
-
-            a<CURSOR>b
-        "#,
-        );
-
-        assert_snapshot!(test.goto_type_definition(), @r###"
-        info: lint:goto-type-definition: Type definition
-         --> /main.py:2:17
-          |
-        2 |             def foo(a, b): ...
-          |                 ^^^
-        3 |
-        4 |             ab = foo
-          |
-        info: Source
-         --> /main.py:6:13
-          |
-        4 |             ab = foo
-        5 |
-        6 |             ab
-          |             ^^
-          |
-        "###);
-    }
-
-    #[test]
-    fn goto_type_of_expression_with_union_type() {
-        let test = cursor_test(
-            r#"
-
-            def foo(a, b): ...
-
-            def bar(a, b): ...
-
-            if random.choice():
-                a = foo
-            else:
-                a = bar
-
-            a<CURSOR>
-            "#,
-        );
-
-        assert_snapshot!(test.goto_type_definition(), @r"
-        info: lint:goto-type-definition: Type definition
-         --> /main.py:3:17
-          |
-        3 |             def foo(a, b): ...
-          |                 ^^^
-        4 |
-        5 |             def bar(a, b): ...
-          |
-        info: Source
-          --> /main.py:12:13
-           |
-        10 |                 a = bar
-        11 |
-        12 |             a
-           |             ^
-           |
-
-        info: lint:goto-type-definition: Type definition
-         --> /main.py:5:17
-          |
-        3 |             def foo(a, b): ...
-        4 |
-        5 |             def bar(a, b): ...
-          |                 ^^^
-        6 |
-        7 |             if random.choice():
-          |
-        info: Source
-          --> /main.py:12:13
-           |
-        10 |                 a = bar
-        11 |
-        12 |             a
-           |             ^
-           |
-        ");
-    }
-
-    #[test]
-    fn goto_type_of_expression_with_module() {
-        let mut test = cursor_test(
-            r#"
-            import lib
-
-            lib<CURSOR>
-            "#,
-        );
-
-        test.write_file("lib.py", "a = 10").unwrap();
-
-        assert_snapshot!(test.goto_type_definition(), @r"
-        info: lint:goto-type-definition: Type definition
-         --> /lib.py:1:1
-          |
-        1 | a = 10
-          | ^^^^^^
-          |
-        info: Source
-         --> /main.py:4:13
-          |
-        2 |             import lib
-        3 |
-        4 |             lib
-          |             ^^^
-          |
-        ");
-    }
-
-    #[test]
-    fn goto_type_of_expression_with_literal_type() {
-        let test = cursor_test(
-            r#"
-            a: str = "test"
-
-            a<CURSOR>
-            "#,
-        );
-
-        assert_snapshot!(test.goto_type_definition(), @r#"
-        info: lint:goto-type-definition: Type definition
-           --> stdlib/builtins.pyi:438:7
-            |
-        436 |     def __getitem__(self, key: int, /) -> str | int | None: ...
-        437 |
-        438 | class str(Sequence[str]):
-            |       ^^^
-        439 |     @overload
-        440 |     def __new__(cls, object: object = ...) -> Self: ...
-            |
-        info: Source
-         --> /main.py:4:13
-          |
-        2 |             a: str = "test"
-        3 |
-        4 |             a
-          |             ^
-          |
-        "#);
-    }
-    #[test]
-    fn goto_type_of_expression_with_literal_node() {
-        let test = cursor_test(
-            r#"
-            a: str = "te<CURSOR>st"
-            "#,
-        );
-
-        assert_snapshot!(test.goto_type_definition(), @r#"
-        info: lint:goto-type-definition: Type definition
-           --> stdlib/builtins.pyi:438:7
-            |
-        436 |     def __getitem__(self, key: int, /) -> str | int | None: ...
-        437 |
-        438 | class str(Sequence[str]):
-            |       ^^^
-        439 |     @overload
-        440 |     def __new__(cls, object: object = ...) -> Self: ...
-            |
-        info: Source
-         --> /main.py:2:22
-          |
-        2 |             a: str = "test"
-          |                      ^^^^^^
-          |
-        "#);
-    }
-
-    #[test]
-    fn goto_type_of_expression_with_type_var_type() {
-        let test = cursor_test(
-            r#"
-            type Alias[T: int = bool] = list[T<CURSOR>]
-            "#,
-        );
-
-        assert_snapshot!(test.goto_type_definition(), @r###"
-        info: lint:goto-type-definition: Type definition
-         --> /main.py:2:24
-          |
-        2 |             type Alias[T: int = bool] = list[T]
-          |                        ^
-          |
-        info: Source
-         --> /main.py:2:46
-          |
-        2 |             type Alias[T: int = bool] = list[T]
-          |                                              ^
-          |
-        "###);
-    }
-
-    #[test]
-    fn goto_type_of_expression_with_type_param_spec() {
-        let test = cursor_test(
-            r#"
-            type Alias[**P = [int, str]] = Callable[P<CURSOR>, int]
-            "#,
-        );
-
-        // TODO: Goto type definition currently doesn't work for type param specs
-        // because the inference doesn't support them yet.
-        // This snapshot should show a single target pointing to `T`
-        assert_snapshot!(test.goto_type_definition(), @"No type definitions found");
-    }
-
-    #[test]
-    fn goto_type_of_expression_with_type_var_tuple() {
-        let test = cursor_test(
-            r#"
-            type Alias[*Ts = ()] = tuple[*Ts<CURSOR>]
-            "#,
-        );
-
-        // TODO: Goto type definition currently doesn't work for type var tuples
-        // because the inference doesn't support them yet.
-        // This snapshot should show a single target pointing to `T`
-        assert_snapshot!(test.goto_type_definition(), @"No type definitions found");
-    }
-
-    #[test]
-    fn goto_type_on_keyword_argument() {
-        let test = cursor_test(
-            r#"
-            def test(a: str): ...
-
-            test(a<CURSOR>= "123")
-            "#,
-        );
-
-        assert_snapshot!(test.goto_type_definition(), @r#"
-        info: lint:goto-type-definition: Type definition
-           --> stdlib/builtins.pyi:438:7
-            |
-        436 |     def __getitem__(self, key: int, /) -> str | int | None: ...
-        437 |
-        438 | class str(Sequence[str]):
-            |       ^^^
-        439 |     @overload
-        440 |     def __new__(cls, object: object = ...) -> Self: ...
-            |
-        info: Source
-         --> /main.py:4:18
-          |
-        2 |             def test(a: str): ...
-        3 |
-        4 |             test(a= "123")
-          |                  ^
-          |
-        "#);
-    }
-
-    #[test]
-    fn goto_type_on_incorrectly_typed_keyword_argument() {
-        let test = cursor_test(
-            r#"
-            def test(a: str): ...
-
-            test(a<CURSOR>= 123)
-            "#,
-        );
-
-        // TODO: This should jump to `str` and not `int` because
-        //   the keyword is typed as a string. It's only the passed argument that
-        //   is an int. Navigating to `str` would match pyright's behavior.
-        assert_snapshot!(test.goto_type_definition(), @r"
-        info: lint:goto-type-definition: Type definition
-           --> stdlib/builtins.pyi:231:7
-            |
-        229 | _LiteralInteger = _PositiveInteger | _NegativeInteger | Literal[0]  # noqa: Y026  # TODO: Use TypeAlias once mypy bugs are fixed
-        230 |
-        231 | class int:
-            |       ^^^
-        232 |     @overload
-        233 |     def __new__(cls, x: ConvertibleToInt = ..., /) -> Self: ...
-            |
-        info: Source
-         --> /main.py:4:18
-          |
-        2 |             def test(a: str): ...
-        3 |
-        4 |             test(a= 123)
-          |                  ^
-          |
-        ");
-    }
-
-    #[test]
-    fn goto_type_on_kwargs() {
-        let test = cursor_test(
-            r#"
-            def f(name: str): ...
-
-kwargs = { "name": "test"}
-
-f(**kwargs<CURSOR>)
-            "#,
-        );
-
-        assert_snapshot!(test.goto_type_definition(), @r#"
-        info: lint:goto-type-definition: Type definition
-            --> stdlib/builtins.pyi:1086:7
-             |
-        1084 |     def __class_getitem__(cls, item: Any, /) -> GenericAlias: ...
-        1085 |
-        1086 | class dict(MutableMapping[_KT, _VT]):
-             |       ^^^^
-        1087 |     # __init__ should be kept roughly in line with `collections.UserDict.__init__`, which has similar semantics
-        1088 |     # Also multiprocessing.managers.SyncManager.dict()
-             |
-        info: Source
-         --> /main.py:6:5
-          |
-        4 | kwargs = { "name": "test"}
-        5 |
-        6 | f(**kwargs)
-          |     ^^^^^^
-          |
-        "#);
-    }
-
-    #[test]
-    fn goto_type_of_expression_with_builtin() {
-        let test = cursor_test(
-            r#"
-            def foo(a: str):
-                a<CURSOR>
-            "#,
-        );
-
-        assert_snapshot!(test.goto_type_definition(), @r"
-        info: lint:goto-type-definition: Type definition
-           --> stdlib/builtins.pyi:438:7
-            |
-        436 |     def __getitem__(self, key: int, /) -> str | int | None: ...
-        437 |
-        438 | class str(Sequence[str]):
-            |       ^^^
-        439 |     @overload
-        440 |     def __new__(cls, object: object = ...) -> Self: ...
-            |
-        info: Source
-         --> /main.py:3:17
-          |
-        2 |             def foo(a: str):
-        3 |                 a
-          |                 ^
-          |
-        ");
-    }
-
-    #[test]
-    fn goto_type_definition_cursor_between_object_and_attribute() {
-        let test = cursor_test(
-            r#"
-            class X:
-                def foo(a, b): ...
-
-            x = X()
-
-            x<CURSOR>.foo()
-            "#,
-        );
-
-        assert_snapshot!(test.goto_type_definition(), @r###"
-        info: lint:goto-type-definition: Type definition
-         --> /main.py:2:19
-          |
-        2 |             class X:
-          |                   ^
-        3 |                 def foo(a, b): ...
-          |
-        info: Source
-         --> /main.py:7:13
-          |
-        5 |             x = X()
-        6 |
-        7 |             x.foo()
-          |             ^
-          |
-        "###);
-    }
-
-    #[test]
-    fn goto_between_call_arguments() {
-        let test = cursor_test(
-            r#"
-            def foo(a, b): ...
-
-            foo<CURSOR>()
-            "#,
-        );
-
-        assert_snapshot!(test.goto_type_definition(), @r###"
-        info: lint:goto-type-definition: Type definition
-         --> /main.py:2:17
-          |
-        2 |             def foo(a, b): ...
-          |                 ^^^
-        3 |
-        4 |             foo()
-          |
-        info: Source
-         --> /main.py:4:13
-          |
-        2 |             def foo(a, b): ...
-        3 |
-        4 |             foo()
-          |             ^^^
-          |
-        "###);
-    }
-
-    #[test]
-    fn goto_type_narrowing() {
-        let test = cursor_test(
-            r#"
-            def foo(a: str | None, b):
-                if a is not None:
-                    print(a<CURSOR>)
-            "#,
-        );
-
-        assert_snapshot!(test.goto_type_definition(), @r"
-        info: lint:goto-type-definition: Type definition
-           --> stdlib/builtins.pyi:438:7
-            |
-        436 |     def __getitem__(self, key: int, /) -> str | int | None: ...
-        437 |
-        438 | class str(Sequence[str]):
-            |       ^^^
-        439 |     @overload
-        440 |     def __new__(cls, object: object = ...) -> Self: ...
-            |
-        info: Source
-         --> /main.py:4:27
-          |
-        2 |             def foo(a: str | None, b):
-        3 |                 if a is not None:
-        4 |                     print(a)
-          |                           ^
-          |
-        ");
-    }
-
-    #[test]
-    fn goto_type_none() {
-        let test = cursor_test(
-            r#"
-            def foo(a: str | None, b):
-                a<CURSOR>
-            "#,
-        );
-
-        assert_snapshot!(test.goto_type_definition(), @r"
-        info: lint:goto-type-definition: Type definition
-           --> stdlib/types.pyi:671:11
-            |
-        669 | if sys.version_info >= (3, 10):
-        670 |     @final
-        671 |     class NoneType:
-            |           ^^^^^^^^
-        672 |         def __bool__(self) -> Literal[False]: ...
-            |
-        info: Source
-         --> /main.py:3:17
-          |
-        2 |             def foo(a: str | None, b):
-        3 |                 a
-          |                 ^
-          |
-
-        info: lint:goto-type-definition: Type definition
-           --> stdlib/builtins.pyi:438:7
-            |
-        436 |     def __getitem__(self, key: int, /) -> str | int | None: ...
-        437 |
-        438 | class str(Sequence[str]):
-            |       ^^^
-        439 |     @overload
-        440 |     def __new__(cls, object: object = ...) -> Self: ...
-            |
-        info: Source
-         --> /main.py:3:17
-          |
-        2 |             def foo(a: str | None, b):
-        3 |                 a
-          |                 ^
-          |
-        ");
-    }
-
-    impl CursorTest {
-        fn goto_type_definition(&self) -> String {
-            let Some(targets) = goto_type_definition(&self.db, self.file, self.cursor_offset)
-            else {
-                return "No goto target found".to_string();
-            };
-
-            if targets.is_empty() {
-                return "No type definitions found".to_string();
-            }
-
-            let source = targets.range;
-            self.render_diagnostics(
-                targets
-                    .into_iter()
-                    .map(|target| GotoTypeDefinitionDiagnostic::new(source, &target)),
-            )
-        }
-    }
-
-    struct GotoTypeDefinitionDiagnostic {
-        source: FileRange,
-        target: FileRange,
-    }
-
-    impl GotoTypeDefinitionDiagnostic {
-        fn new(source: FileRange, target: &NavigationTarget) -> Self {
-            Self {
-                source,
-                target: FileRange::new(target.file(), target.focus_range()),
-            }
-        }
-    }
-
-    impl IntoDiagnostic for GotoTypeDefinitionDiagnostic {
-        fn into_diagnostic(self) -> Diagnostic {
-            let mut source = SubDiagnostic::new(Severity::Info, "Source");
-            source.annotate(Annotation::primary(
-                Span::from(self.source.file()).with_range(self.source.range()),
-            ));
-
-            let mut main = Diagnostic::new(
-                DiagnosticId::Lint(LintName::of("goto-type-definition")),
-                Severity::Info,
-                "Type definition".to_string(),
-            );
-            main.annotate(Annotation::primary(
-                Span::from(self.target.file()).with_range(self.target.range()),
-            ));
-            main.sub(source);
-
-            main
-        }
-    }
-}

crates/red_knot_ide/src/hover.rs

@@ -1,602 +0,0 @@
-use crate::goto::{find_goto_target, GotoTarget};
-use crate::{Db, MarkupKind, RangedValue};
-use red_knot_python_semantic::types::Type;
-use red_knot_python_semantic::SemanticModel;
-use ruff_db::files::{File, FileRange};
-use ruff_db::parsed::parsed_module;
-use ruff_text_size::{Ranged, TextSize};
-use std::fmt;
-use std::fmt::Formatter;
-
-pub fn hover(db: &dyn Db, file: File, offset: TextSize) -> Option<RangedValue<Hover>> {
-    let parsed = parsed_module(db.upcast(), file);
-    let goto_target = find_goto_target(parsed, offset)?;
-
-    if let GotoTarget::Expression(expr) = goto_target {
-        if expr.is_literal_expr() {
-            return None;
-        }
-    }
-
-    let model = SemanticModel::new(db.upcast(), file);
-    let ty = goto_target.inferred_type(&model)?;
-
-    tracing::debug!(
-        "Inferred type of covering node is {}",
-        ty.display(db.upcast())
-    );
-
-    // TODO: Add documentation of the symbol (not the type's definition).
-    // TODO: Render the symbol's signature instead of just its type.
-    let contents = vec![HoverContent::Type(ty)];
-
-    Some(RangedValue {
-        range: FileRange::new(file, goto_target.range()),
-        value: Hover { contents },
-    })
-}
-
-pub struct Hover<'db> {
-    contents: Vec<HoverContent<'db>>,
-}
-
-impl<'db> Hover<'db> {
-    /// Renders the hover to a string using the specified markup kind.
-    pub const fn display<'a>(&'a self, db: &'a dyn Db, kind: MarkupKind) -> DisplayHover<'a> {
-        DisplayHover {
-            db,
-            hover: self,
-            kind,
-        }
-    }
-
-    fn iter(&self) -> std::slice::Iter<'_, HoverContent<'db>> {
-        self.contents.iter()
-    }
-}
-
-impl<'db> IntoIterator for Hover<'db> {
-    type Item = HoverContent<'db>;
-    type IntoIter = std::vec::IntoIter<Self::Item>;
-
-    fn into_iter(self) -> Self::IntoIter {
-        self.contents.into_iter()
-    }
-}
-
-impl<'a, 'db> IntoIterator for &'a Hover<'db> {
-    type Item = &'a HoverContent<'db>;
-    type IntoIter = std::slice::Iter<'a, HoverContent<'db>>;
-
-    fn into_iter(self) -> Self::IntoIter {
-        self.iter()
-    }
-}
-
-pub struct DisplayHover<'a> {
-    db: &'a dyn Db,
-    hover: &'a Hover<'a>,
-    kind: MarkupKind,
-}
-
-impl fmt::Display for DisplayHover<'_> {
-    fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
-        let mut first = true;
-        for content in &self.hover.contents {
-            if !first {
-                self.kind.horizontal_line().fmt(f)?;
-            }
-
-            content.display(self.db, self.kind).fmt(f)?;
-            first = false;
-        }
-
-        Ok(())
-    }
-}
-
-#[derive(Debug, Clone, Eq, PartialEq)]
-pub enum HoverContent<'db> {
-    Type(Type<'db>),
-}
-
-impl<'db> HoverContent<'db> {
-    fn display(&self, db: &'db dyn Db, kind: MarkupKind) -> DisplayHoverContent<'_, 'db> {
-        DisplayHoverContent {
-            db,
-            content: self,
-            kind,
-        }
-    }
-}
-
-pub(crate) struct DisplayHoverContent<'a, 'db> {
-    db: &'db dyn Db,
-    content: &'a HoverContent<'db>,
-    kind: MarkupKind,
-}
-
-impl fmt::Display for DisplayHoverContent<'_, '_> {
-    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        match self.content {
-            HoverContent::Type(ty) => self
-                .kind
-                .fenced_code_block(ty.display(self.db.upcast()), "text")
-                .fmt(f),
-        }
-    }
-}
-
-#[cfg(test)]
-mod tests {
-    use crate::tests::{cursor_test, CursorTest};
-    use crate::{hover, MarkupKind};
-    use insta::assert_snapshot;
-    use ruff_db::diagnostic::{
-        Annotation, Diagnostic, DiagnosticFormat, DiagnosticId, DisplayDiagnosticConfig, LintName,
-        Severity, Span,
-    };
-    use ruff_text_size::{Ranged, TextRange};
-
-    #[test]
-    fn hover_basic() {
-        let test = cursor_test(
-            r#"
-        a = 10
-
-        a<CURSOR>
-        "#,
-        );
-
-        assert_snapshot!(test.hover(), @r"
-        Literal[10]
-        ---------------------------------------------
-        ```text
-        Literal[10]
-        ```
-        ---------------------------------------------
-        info: lint:hover: Hovered content is
-         --> /main.py:4:9
-          |
-        2 |         a = 10
-        3 |
-        4 |         a
-          |         ^- Cursor offset
-          |         |
-          |         source
-          |
-        ");
-    }
-
-    #[test]
-    fn hover_member() {
-        let test = cursor_test(
-            r#"
-        class Foo:
-            a: int = 10
-
-            def __init__(a: int, b: str):
-                self.a = a
-                self.b: str = b
-
-        foo = Foo()
-        foo.<CURSOR>a
-        "#,
-        );
-
-        assert_snapshot!(test.hover(), @r"
-        int
-        ---------------------------------------------
-        ```text
-        int
-        ```
-        ---------------------------------------------
-        info: lint:hover: Hovered content is
-          --> /main.py:10:9
-           |
-         9 |         foo = Foo()
-        10 |         foo.a
-           |         ^^^^-
-           |         |   |
-           |         |   Cursor offset
-           |         source
-           |
-        ");
-    }
-
-    #[test]
-    fn hover_function_typed_variable() {
-        let test = cursor_test(
-            r#"
-            def foo(a, b): ...
-
-            foo<CURSOR>
-        "#,
-        );
-
-        assert_snapshot!(test.hover(), @r###"
-        def foo(a, b) -> Unknown
-        ---------------------------------------------
-        ```text
-        def foo(a, b) -> Unknown
-        ```
-        ---------------------------------------------
-        info: lint:hover: Hovered content is
-         --> /main.py:4:13
-          |
-        2 |             def foo(a, b): ...
-        3 |
-        4 |             foo
-          |             ^^^- Cursor offset
-          |             |
-          |             source
-          |
-        "###);
-    }
-
-    #[test]
-    fn hover_binary_expression() {
-        let test = cursor_test(
-            r#"
-            def foo(a: int, b: int, c: int):
-                a + b ==<CURSOR> c
-        "#,
-        );
-
-        assert_snapshot!(test.hover(), @r"
-        bool
-        ---------------------------------------------
-        ```text
-        bool
-        ```
-        ---------------------------------------------
-        info: lint:hover: Hovered content is
-         --> /main.py:3:17
-          |
-        2 |             def foo(a: int, b: int, c: int):
-        3 |                 a + b == c
-          |                 ^^^^^^^^-^
-          |                 |       |
-          |                 |       Cursor offset
-          |                 source
-          |
-        ");
-    }
-
-    #[test]
-    fn hover_keyword_parameter() {
-        let test = cursor_test(
-            r#"
-            def test(a: int): ...
-
-            test(a<CURSOR>= 123)
-            "#,
-        );
-
-        // TODO: This should reveal `int` because the user hovers over the parameter and not the value.
-        assert_snapshot!(test.hover(), @r"
-        Literal[123]
-        ---------------------------------------------
-        ```text
-        Literal[123]
-        ```
-        ---------------------------------------------
-        info: lint:hover: Hovered content is
-         --> /main.py:4:18
-          |
-        2 |             def test(a: int): ...
-        3 |
-        4 |             test(a= 123)
-          |                  ^- Cursor offset
-          |                  |
-          |                  source
-          |
-        ");
-    }
-
-    #[test]
-    fn hover_union() {
-        let test = cursor_test(
-            r#"
-
-            def foo(a, b): ...
-
-            def bar(a, b): ...
-
-            if random.choice([True, False]):
-                a = foo
-            else:
-                a = bar
-
-            a<CURSOR>
-            "#,
-        );
-
-        assert_snapshot!(test.hover(), @r###"
-        (def foo(a, b) -> Unknown) | (def bar(a, b) -> Unknown)
-        ---------------------------------------------
-        ```text
-        (def foo(a, b) -> Unknown) | (def bar(a, b) -> Unknown)
-        ```
-        ---------------------------------------------
-        info: lint:hover: Hovered content is
-          --> /main.py:12:13
-           |
-        10 |                 a = bar
-        11 |
-        12 |             a
-           |             ^- Cursor offset
-           |             |
-           |             source
-           |
-        "###);
-    }
-
-    #[test]
-    fn hover_module() {
-        let mut test = cursor_test(
-            r#"
-            import lib
-
-            li<CURSOR>b
-            "#,
-        );
-
-        test.write_file("lib.py", "a = 10").unwrap();
-
-        assert_snapshot!(test.hover(), @r"
-        <module 'lib'>
-        ---------------------------------------------
-        ```text
-        <module 'lib'>
-        ```
-        ---------------------------------------------
-        info: lint:hover: Hovered content is
-         --> /main.py:4:13
-          |
-        2 |             import lib
-        3 |
-        4 |             lib
-          |             ^^-
-          |             | |
-          |             | Cursor offset
-          |             source
-          |
-        ");
-    }
-
-    #[test]
-    fn hover_type_of_expression_with_type_var_type() {
-        let test = cursor_test(
-            r#"
-            type Alias[T: int = bool] = list[T<CURSOR>]
-            "#,
-        );
-
-        assert_snapshot!(test.hover(), @r"
-        T
-        ---------------------------------------------
-        ```text
-        T
-        ```
-        ---------------------------------------------
-        info: lint:hover: Hovered content is
-         --> /main.py:2:46
-          |
-        2 |             type Alias[T: int = bool] = list[T]
-          |                                              ^- Cursor offset
-          |                                              |
-          |                                              source
-          |
-        ");
-    }
-
-    #[test]
-    fn hover_type_of_expression_with_type_param_spec() {
-        let test = cursor_test(
-            r#"
-            type Alias[**P = [int, str]] = Callable[P<CURSOR>, int]
-            "#,
-        );
-
-        assert_snapshot!(test.hover(), @r"
-        @Todo
-        ---------------------------------------------
-        ```text
-        @Todo
-        ```
-        ---------------------------------------------
-        info: lint:hover: Hovered content is
-         --> /main.py:2:53
-          |
-        2 |             type Alias[**P = [int, str]] = Callable[P, int]
-          |                                                     ^- Cursor offset
-          |                                                     |
-          |                                                     source
-          |
-        ");
-    }
-
-    #[test]
-    fn hover_type_of_expression_with_type_var_tuple() {
-        let test = cursor_test(
-            r#"
-            type Alias[*Ts = ()] = tuple[*Ts<CURSOR>]
-            "#,
-        );
-
-        assert_snapshot!(test.hover(), @r"
-        @Todo
-        ---------------------------------------------
-        ```text
-        @Todo
-        ```
-        ---------------------------------------------
-        info: lint:hover: Hovered content is
-         --> /main.py:2:43
-          |
-        2 |             type Alias[*Ts = ()] = tuple[*Ts]
-          |                                           ^^- Cursor offset
-          |                                           |
-          |                                           source
-          |
-        ");
-    }
-
-    #[test]
-    fn hover_class_member_declaration() {
-        let test = cursor_test(
-            r#"
-        class Foo:
-            a<CURSOR>: int
-        "#,
-        );
-
-        // TODO: This should be int and not `Never`, https://github.com/astral-sh/ruff/issues/17122
-        assert_snapshot!(test.hover(), @r"
-        Never
-        ---------------------------------------------
-        ```text
-        Never
-        ```
-        ---------------------------------------------
-        info: lint:hover: Hovered content is
-         --> /main.py:3:13
-          |
-        2 |         class Foo:
-        3 |             a: int
-          |             ^- Cursor offset
-          |             |
-          |             source
-          |
-        ");
-    }
-
-    #[test]
-    fn hover_type_narrowing() {
-        let test = cursor_test(
-            r#"
-            def foo(a: str | None, b):
-                if a is not None:
-                    print(a<CURSOR>)
-            "#,
-        );
-
-        assert_snapshot!(test.hover(), @r"
-        str
-        ---------------------------------------------
-        ```text
-        str
-        ```
-        ---------------------------------------------
-        info: lint:hover: Hovered content is
-         --> /main.py:4:27
-          |
-        2 |             def foo(a: str | None, b):
-        3 |                 if a is not None:
-        4 |                     print(a)
-          |                           ^- Cursor offset
-          |                           |
-          |                           source
-          |
-        ");
-    }
-
-    #[test]
-    fn hover_whitespace() {
-        let test = cursor_test(
-            r#"
-        class C:
-            <CURSOR>
-            foo: str = 'bar'
-        "#,
-        );
-
-        assert_snapshot!(test.hover(), @"Hover provided no content");
-    }
-
-    #[test]
-    fn hover_literal_int() {
-        let test = cursor_test(
-            r#"
-        print(
-            0 + 1<CURSOR>
-        )
-        "#,
-        );
-
-        assert_snapshot!(test.hover(), @"Hover provided no content");
-    }
-
-    #[test]
-    fn hover_literal_ellipsis() {
-        let test = cursor_test(
-            r#"
-        print(
-            .<CURSOR>..
-        )
-        "#,
-        );
-
-        assert_snapshot!(test.hover(), @"Hover provided no content");
-    }
-
-    #[test]
-    fn hover_docstring() {
-        let test = cursor_test(
-            r#"
-        def f():
-            """Lorem ipsum dolor sit amet.<CURSOR>"""
-        "#,
-        );
-
-        assert_snapshot!(test.hover(), @"Hover provided no content");
-    }
-
-    impl CursorTest {
-        fn hover(&self) -> String {
-            use std::fmt::Write;
-
-            let Some(hover) = hover(&self.db, self.file, self.cursor_offset) else {
-                return "Hover provided no content".to_string();
-            };
-
-            let source = hover.range;
-
-            let mut buf = String::new();
-
-            write!(
-                &mut buf,
-                "{plaintext}{line}{markdown}{line}",
-                plaintext = hover.display(&self.db, MarkupKind::PlainText),
-                line = MarkupKind::PlainText.horizontal_line(),
-                markdown = hover.display(&self.db, MarkupKind::Markdown),
-            )
-            .unwrap();
-
-            let config = DisplayDiagnosticConfig::default()
-                .color(false)
-                .format(DiagnosticFormat::Full);
-
-            let mut diagnostic = Diagnostic::new(
-                DiagnosticId::Lint(LintName::of("hover")),
-                Severity::Info,
-                "Hovered content is",
-            );
-            diagnostic.annotate(
-                Annotation::primary(Span::from(source.file()).with_range(source.range()))
-                    .message("source"),
-            );
-            diagnostic.annotate(
-                Annotation::secondary(
-                    Span::from(source.file()).with_range(TextRange::empty(self.cursor_offset)),
-                )
-                .message("Cursor offset"),
-            );
-
-            write!(buf, "{}", diagnostic.display(&self.db, &config)).unwrap();
-
-            buf
-        }
-    }
-}

crates/red_knot_ide/src/inlay_hints.rs

@@ -1,279 +0,0 @@
-use crate::Db;
-use red_knot_python_semantic::types::Type;
-use red_knot_python_semantic::{HasType, SemanticModel};
-use ruff_db::files::File;
-use ruff_db::parsed::parsed_module;
-use ruff_python_ast::visitor::source_order::{self, SourceOrderVisitor, TraversalSignal};
-use ruff_python_ast::{AnyNodeRef, Expr, Stmt};
-use ruff_text_size::{Ranged, TextRange, TextSize};
-use std::fmt;
-use std::fmt::Formatter;
-
-#[derive(Debug, Clone, Eq, PartialEq)]
-pub struct InlayHint<'db> {
-    pub position: TextSize,
-    pub content: InlayHintContent<'db>,
-}
-
-impl<'db> InlayHint<'db> {
-    pub const fn display(&self, db: &'db dyn Db) -> DisplayInlayHint<'_, 'db> {
-        self.content.display(db)
-    }
-}
-
-#[derive(Debug, Clone, Eq, PartialEq)]
-pub enum InlayHintContent<'db> {
-    Type(Type<'db>),
-    ReturnType(Type<'db>),
-}
-
-impl<'db> InlayHintContent<'db> {
-    pub const fn display(&self, db: &'db dyn Db) -> DisplayInlayHint<'_, 'db> {
-        DisplayInlayHint { db, hint: self }
-    }
-}
-
-pub struct DisplayInlayHint<'a, 'db> {
-    db: &'db dyn Db,
-    hint: &'a InlayHintContent<'db>,
-}
-
-impl fmt::Display for DisplayInlayHint<'_, '_> {
-    fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
-        match self.hint {
-            InlayHintContent::Type(ty) => {
-                write!(f, ": {}", ty.display(self.db.upcast()))
-            }
-            InlayHintContent::ReturnType(ty) => {
-                write!(f, " -> {}", ty.display(self.db.upcast()))
-            }
-        }
-    }
-}
-
-pub fn inlay_hints(db: &dyn Db, file: File, range: TextRange) -> Vec<InlayHint<'_>> {
-    let mut visitor = InlayHintVisitor::new(db, file, range);
-
-    let ast = parsed_module(db.upcast(), file);
-
-    visitor.visit_body(ast.suite());
-
-    visitor.hints
-}
-
-struct InlayHintVisitor<'db> {
-    model: SemanticModel<'db>,
-    hints: Vec<InlayHint<'db>>,
-    in_assignment: bool,
-    range: TextRange,
-}
-
-impl<'db> InlayHintVisitor<'db> {
-    fn new(db: &'db dyn Db, file: File, range: TextRange) -> Self {
-        Self {
-            model: SemanticModel::new(db.upcast(), file),
-            hints: Vec::new(),
-            in_assignment: false,
-            range,
-        }
-    }
-
-    fn add_type_hint(&mut self, position: TextSize, ty: Type<'db>) {
-        self.hints.push(InlayHint {
-            position,
-            content: InlayHintContent::Type(ty),
-        });
-    }
-}
-
-impl SourceOrderVisitor<'_> for InlayHintVisitor<'_> {
-    fn enter_node(&mut self, node: AnyNodeRef<'_>) -> TraversalSignal {
-        if self.range.intersect(node.range()).is_some() {
-            TraversalSignal::Traverse
-        } else {
-            TraversalSignal::Skip
-        }
-    }
-
-    fn visit_stmt(&mut self, stmt: &Stmt) {
-        let node = AnyNodeRef::from(stmt);
-
-        if !self.enter_node(node).is_traverse() {
-            return;
-        }
-
-        match stmt {
-            Stmt::Assign(assign) => {
-                self.in_assignment = true;
-                for target in &assign.targets {
-                    self.visit_expr(target);
-                }
-                self.in_assignment = false;
-
-                return;
-            }
-            // TODO
-            Stmt::FunctionDef(_) => {}
-            Stmt::For(_) => {}
-            Stmt::Expr(_) => {
-                // Don't traverse into expression statements because we don't show any hints.
-                return;
-            }
-            _ => {}
-        }
-
-        source_order::walk_stmt(self, stmt);
-    }
-
-    fn visit_expr(&mut self, expr: &'_ Expr) {
-        if !self.in_assignment {
-            return;
-        }
-
-        match expr {
-            Expr::Name(name) => {
-                if name.ctx.is_store() {
-                    let ty = expr.inferred_type(&self.model);
-                    self.add_type_hint(expr.range().end(), ty);
-                }
-            }
-            _ => {
-                source_order::walk_expr(self, expr);
-            }
-        }
-    }
-}
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-
-    use insta::assert_snapshot;
-    use ruff_db::{
-        files::{system_path_to_file, File},
-        source::source_text,
-    };
-    use ruff_text_size::TextSize;
-
-    use crate::db::tests::TestDb;
-
-    use red_knot_python_semantic::{
-        Program, ProgramSettings, PythonPath, PythonPlatform, SearchPathSettings,
-    };
-    use ruff_db::system::{DbWithWritableSystem, SystemPathBuf};
-    use ruff_python_ast::PythonVersion;
-
-    pub(super) fn inlay_hint_test(source: &str) -> InlayHintTest {
-        const START: &str = "<START>";
-        const END: &str = "<END>";
-
-        let mut db = TestDb::new();
-
-        let start = source.find(START);
-        let end = source
-            .find(END)
-            .map(|x| if start.is_some() { x - START.len() } else { x })
-            .unwrap_or(source.len());
-
-        let range = TextRange::new(
-            TextSize::try_from(start.unwrap_or_default()).unwrap(),
-            TextSize::try_from(end).unwrap(),
-        );
-
-        let source = source.replace(START, "");
-        let source = source.replace(END, "");
-
-        db.write_file("main.py", source)
-            .expect("write to memory file system to be successful");
-
-        let file = system_path_to_file(&db, "main.py").expect("newly written file to existing");
-
-        Program::from_settings(
-            &db,
-            ProgramSettings {
-                python_version: PythonVersion::latest(),
-                python_platform: PythonPlatform::default(),
-                search_paths: SearchPathSettings {
-                    extra_paths: vec![],
-                    src_roots: vec![SystemPathBuf::from("/")],
-                    custom_typeshed: None,
-                    python_path: PythonPath::KnownSitePackages(vec![]),
-                },
-            },
-        )
-        .expect("Default settings to be valid");
-
-        InlayHintTest { db, file, range }
-    }
-
-    pub(super) struct InlayHintTest {
-        pub(super) db: TestDb,
-        pub(super) file: File,
-        pub(super) range: TextRange,
-    }
-
-    impl InlayHintTest {
-        fn inlay_hints(&self) -> String {
-            let hints = inlay_hints(&self.db, self.file, self.range);
-
-            let mut buf = source_text(&self.db, self.file).as_str().to_string();
-
-            let mut offset = 0;
-
-            for hint in hints {
-                let end_position = (hint.position.to_u32() as usize) + offset;
-                let hint_str = format!("[{}]", hint.display(&self.db));
-                buf.insert_str(end_position, &hint_str);
-                offset += hint_str.len();
-            }
-
-            buf
-        }
-    }
-
-    #[test]
-    fn test_assign_statement() {
-        let test = inlay_hint_test("x = 1");
-
-        assert_snapshot!(test.inlay_hints(), @r"
-        x[: Literal[1]] = 1
-        ");
-    }
-
-    #[test]
-    fn test_tuple_assignment() {
-        let test = inlay_hint_test("x, y = (1, 'abc')");
-
-        assert_snapshot!(test.inlay_hints(), @r#"
-        x[: Literal[1]], y[: Literal["abc"]] = (1, 'abc')
-        "#);
-    }
-
-    #[test]
-    fn test_nested_tuple_assignment() {
-        let test = inlay_hint_test("x, (y, z) = (1, ('abc', 2))");
-
-        assert_snapshot!(test.inlay_hints(), @r#"
-        x[: Literal[1]], (y[: Literal["abc"]], z[: Literal[2]]) = (1, ('abc', 2))
-        "#);
-    }
-
-    #[test]
-    fn test_assign_statement_with_type_annotation() {
-        let test = inlay_hint_test("x: int = 1");
-
-        assert_snapshot!(test.inlay_hints(), @r"
-        x: int = 1
-        ");
-    }
-
-    #[test]
-    fn test_assign_statement_out_of_range() {
-        let test = inlay_hint_test("<START>x = 1<END>\ny = 2");
-
-        assert_snapshot!(test.inlay_hints(), @r"
-        x[: Literal[1]] = 1
-        y = 2
-        ");
-    }
-}

crates/red_knot_ide/src/lib.rs

@@ -1,296 +0,0 @@
-mod db;
-mod find_node;
-mod goto;
-mod hover;
-mod inlay_hints;
-mod markup;
-
-pub use db::Db;
-pub use goto::goto_type_definition;
-pub use hover::hover;
-pub use inlay_hints::inlay_hints;
-pub use markup::MarkupKind;
-
-use rustc_hash::FxHashSet;
-use std::ops::{Deref, DerefMut};
-
-use red_knot_python_semantic::types::{Type, TypeDefinition};
-use ruff_db::files::{File, FileRange};
-use ruff_text_size::{Ranged, TextRange};
-
-/// Information associated with a text range.
-#[derive(Debug, Copy, Clone, Eq, PartialEq, Hash)]
-pub struct RangedValue<T> {
-    pub range: FileRange,
-    pub value: T,
-}
-
-impl<T> RangedValue<T> {
-    pub fn file_range(&self) -> FileRange {
-        self.range
-    }
-}
-
-impl<T> Deref for RangedValue<T> {
-    type Target = T;
-
-    fn deref(&self) -> &Self::Target {
-        &self.value
-    }
-}
-
-impl<T> DerefMut for RangedValue<T> {
-    fn deref_mut(&mut self) -> &mut Self::Target {
-        &mut self.value
-    }
-}
-
-impl<T> IntoIterator for RangedValue<T>
-where
-    T: IntoIterator,
-{
-    type Item = T::Item;
-    type IntoIter = T::IntoIter;
-
-    fn into_iter(self) -> Self::IntoIter {
-        self.value.into_iter()
-    }
-}
-
-/// Target to which the editor can navigate to.
-#[derive(Debug, Clone, PartialEq, Eq, Hash)]
-pub struct NavigationTarget {
-    file: File,
-
-    /// The range that should be focused when navigating to the target.
-    ///
-    /// This is typically not the full range of the node. For example, it's the range of the class's name in a class definition.
-    ///
-    /// The `focus_range` must be fully covered by `full_range`.
-    focus_range: TextRange,
-
-    /// The range covering the entire target.
-    full_range: TextRange,
-}
-
-impl NavigationTarget {
-    pub fn file(&self) -> File {
-        self.file
-    }
-
-    pub fn focus_range(&self) -> TextRange {
-        self.focus_range
-    }
-
-    pub fn full_range(&self) -> TextRange {
-        self.full_range
-    }
-}
-
-#[derive(Debug, Clone)]
-pub struct NavigationTargets(smallvec::SmallVec<[NavigationTarget; 1]>);
-
-impl NavigationTargets {
-    fn single(target: NavigationTarget) -> Self {
-        Self(smallvec::smallvec![target])
-    }
-
-    fn empty() -> Self {
-        Self(smallvec::SmallVec::new())
-    }
-
-    fn unique(targets: impl IntoIterator<Item = NavigationTarget>) -> Self {
-        let unique: FxHashSet<_> = targets.into_iter().collect();
-        if unique.is_empty() {
-            Self::empty()
-        } else {
-            let mut targets = unique.into_iter().collect::<Vec<_>>();
-            targets.sort_by_key(|target| (target.file, target.focus_range.start()));
-            Self(targets.into())
-        }
-    }
-
-    fn iter(&self) -> std::slice::Iter<'_, NavigationTarget> {
-        self.0.iter()
-    }
-
-    #[cfg(test)]
-    fn is_empty(&self) -> bool {
-        self.0.is_empty()
-    }
-}
-
-impl IntoIterator for NavigationTargets {
-    type Item = NavigationTarget;
-    type IntoIter = smallvec::IntoIter<[NavigationTarget; 1]>;
-
-    fn into_iter(self) -> Self::IntoIter {
-        self.0.into_iter()
-    }
-}
-
-impl<'a> IntoIterator for &'a NavigationTargets {
-    type Item = &'a NavigationTarget;
-    type IntoIter = std::slice::Iter<'a, NavigationTarget>;
-
-    fn into_iter(self) -> Self::IntoIter {
-        self.iter()
-    }
-}
-
-impl FromIterator<NavigationTarget> for NavigationTargets {
-    fn from_iter<T: IntoIterator<Item = NavigationTarget>>(iter: T) -> Self {
-        Self::unique(iter)
-    }
-}
-
-pub trait HasNavigationTargets {
-    fn navigation_targets(&self, db: &dyn Db) -> NavigationTargets;
-}
-
-impl HasNavigationTargets for Type<'_> {
-    fn navigation_targets(&self, db: &dyn Db) -> NavigationTargets {
-        match self {
-            Type::Union(union) => union
-                .iter(db.upcast())
-                .flat_map(|target| target.navigation_targets(db))
-                .collect(),
-
-            Type::Intersection(intersection) => {
-                // Only consider the positive elements because the negative elements are mainly from narrowing constraints.
-                let mut targets = intersection
-                    .iter_positive(db.upcast())
-                    .filter(|ty| !ty.is_unknown());
-
-                let Some(first) = targets.next() else {
-                    return NavigationTargets::empty();
-                };
-
-                match targets.next() {
-                    Some(_) => {
-                        // If there are multiple types in the intersection, we can't navigate to a single one
-                        // because the type is the intersection of all those types.
-                        NavigationTargets::empty()
-                    }
-                    None => first.navigation_targets(db),
-                }
-            }
-
-            ty => ty
-                .definition(db.upcast())
-                .map(|definition| definition.navigation_targets(db))
-                .unwrap_or_else(NavigationTargets::empty),
-        }
-    }
-}
-
-impl HasNavigationTargets for TypeDefinition<'_> {
-    fn navigation_targets(&self, db: &dyn Db) -> NavigationTargets {
-        let full_range = self.full_range(db.upcast());
-        NavigationTargets::single(NavigationTarget {
-            file: full_range.file(),
-            focus_range: self.focus_range(db.upcast()).unwrap_or(full_range).range(),
-            full_range: full_range.range(),
-        })
-    }
-}
-
-#[cfg(test)]
-mod tests {
-    use crate::db::tests::TestDb;
-    use insta::internals::SettingsBindDropGuard;
-    use red_knot_python_semantic::{
-        Program, ProgramSettings, PythonPath, PythonPlatform, SearchPathSettings,
-    };
-    use ruff_db::diagnostic::{Diagnostic, DiagnosticFormat, DisplayDiagnosticConfig};
-    use ruff_db::files::{system_path_to_file, File};
-    use ruff_db::system::{DbWithWritableSystem, SystemPath, SystemPathBuf};
-    use ruff_python_ast::PythonVersion;
-    use ruff_text_size::TextSize;
-
-    pub(super) fn cursor_test(source: &str) -> CursorTest {
-        let mut db = TestDb::new();
-        let cursor_offset = source.find("<CURSOR>").expect(
-            "`source`` should contain a `<CURSOR>` marker, indicating the position of the cursor.",
-        );
-
-        let mut content = source[..cursor_offset].to_string();
-        content.push_str(&source[cursor_offset + "<CURSOR>".len()..]);
-
-        db.write_file("main.py", &content)
-            .expect("write to memory file system to be successful");
-
-        let file = system_path_to_file(&db, "main.py").expect("newly written file to existing");
-
-        Program::from_settings(
-            &db,
-            ProgramSettings {
-                python_version: PythonVersion::latest(),
-                python_platform: PythonPlatform::default(),
-                search_paths: SearchPathSettings {
-                    extra_paths: vec![],
-                    src_roots: vec![SystemPathBuf::from("/")],
-                    custom_typeshed: None,
-                    python_path: PythonPath::KnownSitePackages(vec![]),
-                },
-            },
-        )
-        .expect("Default settings to be valid");
-
-        let mut insta_settings = insta::Settings::clone_current();
-        insta_settings.add_filter(r#"\\(\w\w|\s|\.|")"#, "/$1");
-        // Filter out TODO types because they are different between debug and release builds.
-        insta_settings.add_filter(r"@Todo\(.+\)", "@Todo");
-
-        let insta_settings_guard = insta_settings.bind_to_scope();
-
-        CursorTest {
-            db,
-            cursor_offset: TextSize::try_from(cursor_offset)
-                .expect("source to be smaller than 4GB"),
-            file,
-            _insta_settings_guard: insta_settings_guard,
-        }
-    }
-
-    pub(super) struct CursorTest {
-        pub(super) db: TestDb,
-        pub(super) cursor_offset: TextSize,
-        pub(super) file: File,
-        _insta_settings_guard: SettingsBindDropGuard,
-    }
-
-    impl CursorTest {
-        pub(super) fn write_file(
-            &mut self,
-            path: impl AsRef<SystemPath>,
-            content: &str,
-        ) -> std::io::Result<()> {
-            self.db.write_file(path, content)
-        }
-
-        pub(super) fn render_diagnostics<I, D>(&self, diagnostics: I) -> String
-        where
-            I: IntoIterator<Item = D>,
-            D: IntoDiagnostic,
-        {
-            use std::fmt::Write;
-
-            let mut buf = String::new();
-
-            let config = DisplayDiagnosticConfig::default()
-                .color(false)
-                .format(DiagnosticFormat::Full);
-            for diagnostic in diagnostics {
-                let diag = diagnostic.into_diagnostic();
-                write!(buf, "{}", diag.display(&self.db, &config)).unwrap();
-            }
-
-            buf
-        }
-    }
-
-    pub(super) trait IntoDiagnostic {
-        fn into_diagnostic(self) -> Diagnostic;
-    }
-}

crates/red_knot_ide/src/markup.rs

@@ -1,66 +0,0 @@
-use std::fmt;
-use std::fmt::Formatter;
-
-#[derive(Debug, Copy, Clone, Eq, PartialEq)]
-pub enum MarkupKind {
-    PlainText,
-    Markdown,
-}
-
-impl MarkupKind {
-    pub(crate) const fn fenced_code_block<T>(self, code: T, language: &str) -> FencedCodeBlock<T>
-    where
-        T: fmt::Display,
-    {
-        FencedCodeBlock {
-            language,
-            code,
-            kind: self,
-        }
-    }
-
-    pub(crate) const fn horizontal_line(self) -> HorizontalLine {
-        HorizontalLine { kind: self }
-    }
-}
-
-pub(crate) struct FencedCodeBlock<'a, T> {
-    language: &'a str,
-    code: T,
-    kind: MarkupKind,
-}
-
-impl<T> fmt::Display for FencedCodeBlock<'_, T>
-where
-    T: fmt::Display,
-{
-    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        match self.kind {
-            MarkupKind::PlainText => self.code.fmt(f),
-            MarkupKind::Markdown => write!(
-                f,
-                "```{language}\n{code}\n```",
-                language = self.language,
-                code = self.code
-            ),
-        }
-    }
-}
-
-#[derive(Debug, Copy, Clone)]
-pub(crate) struct HorizontalLine {
-    kind: MarkupKind,
-}
-
-impl fmt::Display for HorizontalLine {
-    fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
-        match self.kind {
-            MarkupKind::PlainText => {
-                f.write_str("\n---------------------------------------------\n")
-            }
-            MarkupKind::Markdown => {
-                write!(f, "\n---\n")
-            }
-        }
-    }
-}

crates/red_knot_module_resolver/Cargo.toml

@@ -1,5 +1,5 @@
 [package]
-name = "red_knot_vendored"
+name = "red_knot_module_resolver"
 version = "0.0.0"
 publish = false
 authors = { workspace = true }
@@ -12,20 +12,25 @@ license = { workspace = true }
 
 [dependencies]
 ruff_db = { workspace = true }
+ruff_python_stdlib = { workspace = true }
+
+compact_str = { workspace = true }
+camino = { workspace = true }
+rustc-hash = { workspace = true }
+salsa = { workspace = true }
+tracing = { workspace = true }
 zip = { workspace = true }
 
 [build-dependencies]
 path-slash = { workspace = true }
 walkdir = { workspace = true }
-zip = { workspace = true, features = ["zstd", "deflate"] }
+zip = { workspace = true }
 
 [dev-dependencies]
+anyhow = { workspace = true }
+insta = { workspace = true }
+tempfile = { workspace = true }
 walkdir = { workspace = true }
 
-[features]
-zstd = ["zip/zstd"]
-deflate = ["zip/deflate"]
-
 [lints]
 workspace = true
-

crates/red_knot_module_resolver/README.md

@@ -1,5 +1,9 @@
-# Vendored types for the stdlib
+# Red Knot
 
-This crate vendors [typeshed](https://github.com/python/typeshed)'s stubs for the standard library. The vendored stubs can be found in `crates/red_knot_vendored/vendor/typeshed`. The file `crates/red_knot_vendored/vendor/typeshed/source_commit.txt` tells you the typeshed commit that our vendored stdlib stubs currently correspond to.
+A work-in-progress multifile module resolver for Ruff.
+
+## Vendored types for the stdlib
+
+This crate vendors [typeshed](https://github.com/python/typeshed)'s stubs for the standard library. The vendored stubs can be found in `crates/red_knot_module_resolver/vendor/typeshed`. The file `crates/red_knot_module_resolver/vendor/typeshed/source_commit.txt` tells you the typeshed commit that our vendored stdlib stubs currently correspond to.
 
 The typeshed stubs are updated every two weeks via an automated PR using the `sync_typeshed.yaml` workflow in the `.github/workflows` directory. This workflow can also be triggered at any time via [workflow dispatch](https://docs.github.com/en/actions/using-workflows/manually-running-a-workflow#running-a-workflow).

crates/red_knot_module_resolver/build.rs

@@ -3,10 +3,9 @@
 //!
 //! This script should be automatically run at build time
 //! whenever the script itself changes, or whenever any files
-//! in `crates/red_knot_vendored/vendor/typeshed` change.
+//! in `crates/red_knot_module_resolver/vendor/typeshed` change.
 
 use std::fs::File;
-use std::io::Write;
 use std::path::Path;
 
 use path_slash::PathExt;
@@ -15,41 +14,24 @@ use zip::write::{FileOptions, ZipWriter};
 use zip::CompressionMethod;
 
 const TYPESHED_SOURCE_DIR: &str = "vendor/typeshed";
-const KNOT_EXTENSIONS_STUBS: &str = "knot_extensions/knot_extensions.pyi";
 const TYPESHED_ZIP_LOCATION: &str = "/zipped_typeshed.zip";
 
-/// Recursively zip the contents of the entire typeshed directory and patch typeshed
-/// on the fly to include the `knot_extensions` module.
+/// Recursively zip the contents of an entire directory.
 ///
 /// This routine is adapted from a recipe at
 /// <https://github.com/zip-rs/zip-old/blob/5d0f198124946b7be4e5969719a7f29f363118cd/examples/write_dir.rs>
-fn write_zipped_typeshed_to(writer: File) -> ZipResult<File> {
+fn zip_dir(directory_path: &str, writer: File) -> ZipResult<File> {
     let mut zip = ZipWriter::new(writer);
 
-    // Use deflated compression for WASM builds because compiling `zstd-sys` requires clang
-    // [source](https://github.com/gyscos/zstd-rs/wiki/Compile-for-WASM) which complicates the build
-    // by a lot. Deflated compression is slower but it shouldn't matter much for the WASM use case
-    // (WASM itself is already slower than a native build for a specific platform).
-    // We can't use `#[cfg(...)]` here because the target-arch in a build script is the
-    // architecture of the system running the build script and not the architecture of the build-target.
-    // That's why we use the `TARGET` environment variable here.
-    let method = if cfg!(feature = "zstd") {
-        CompressionMethod::Zstd
-    } else if cfg!(feature = "deflate") {
-        CompressionMethod::Deflated
-    } else {
-        CompressionMethod::Stored
-    };
-
     let options = FileOptions::default()
-        .compression_method(method)
+        .compression_method(CompressionMethod::Zstd)
         .unix_permissions(0o644);
 
-    for entry in walkdir::WalkDir::new(TYPESHED_SOURCE_DIR) {
+    for entry in walkdir::WalkDir::new(directory_path) {
         let dir_entry = entry.unwrap();
         let absolute_path = dir_entry.path();
         let normalized_relative_path = absolute_path
-            .strip_prefix(Path::new(TYPESHED_SOURCE_DIR))
+            .strip_prefix(Path::new(directory_path))
             .unwrap()
             .to_slash()
             .expect("Unexpected non-utf8 typeshed path!");
@@ -58,14 +40,9 @@ fn write_zipped_typeshed_to(writer: File) -> ZipResult<File> {
         // Some unzip tools unzip files with directory paths correctly, some do not!
         if absolute_path.is_file() {
             println!("adding file {absolute_path:?} as {normalized_relative_path:?} ...");
-            zip.start_file(&*normalized_relative_path, options)?;
+            zip.start_file(normalized_relative_path, options)?;
             let mut f = File::open(absolute_path)?;
             std::io::copy(&mut f, &mut zip).unwrap();
-
-            // Patch the VERSIONS file to make `knot_extensions` available
-            if normalized_relative_path == "stdlib/VERSIONS" {
-                writeln!(&mut zip, "knot_extensions: 3.0-")?;
-            }
         } else if !normalized_relative_path.is_empty() {
             // Only if not root! Avoids path spec / warning
             // and mapname conversion failed error on unzip
@@ -73,17 +50,11 @@ fn write_zipped_typeshed_to(writer: File) -> ZipResult<File> {
             zip.add_directory(normalized_relative_path, options)?;
         }
     }
-
-    // Patch typeshed and add the stubs for the `knot_extensions` module
-    println!("adding file {KNOT_EXTENSIONS_STUBS} as stdlib/knot_extensions.pyi ...");
-    zip.start_file("stdlib/knot_extensions.pyi", options)?;
-    let mut f = File::open(KNOT_EXTENSIONS_STUBS)?;
-    std::io::copy(&mut f, &mut zip).unwrap();
-
     zip.finish()
 }
 
 fn main() {
+    println!("cargo:rerun-if-changed={TYPESHED_SOURCE_DIR}");
     assert!(
         Path::new(TYPESHED_SOURCE_DIR).is_dir(),
         "Where is typeshed?"
@@ -98,6 +69,6 @@ fn main() {
     // which can't be done at compile time.)
     let zipped_typeshed_location = format!("{out_dir}{TYPESHED_ZIP_LOCATION}");
 
-    let zipped_typeshed_file = File::create(zipped_typeshed_location).unwrap();
-    write_zipped_typeshed_to(zipped_typeshed_file).unwrap();
+    let zipped_typeshed = File::create(zipped_typeshed_location).unwrap();
+    zip_dir(TYPESHED_SOURCE_DIR, zipped_typeshed).unwrap();
 }

crates/red_knot_module_resolver/src/db.rs

@@ -0,0 +1,264 @@
+use ruff_db::Upcast;
+
+use crate::resolver::{
+    file_to_module,
+    internal::{ModuleNameIngredient, ModuleResolverSettings},
+    resolve_module_query,
+};
+use crate::typeshed::parse_typeshed_versions;
+
+#[salsa::jar(db=Db)]
+pub struct Jar(
+    ModuleNameIngredient<'_>,
+    ModuleResolverSettings,
+    resolve_module_query,
+    file_to_module,
+    parse_typeshed_versions,
+);
+
+pub trait Db: salsa::DbWithJar<Jar> + ruff_db::Db + Upcast<dyn ruff_db::Db> {}
+
+#[cfg(test)]
+pub(crate) mod tests {
+    use std::sync;
+
+    use salsa::DebugWithDb;
+
+    use ruff_db::file_system::{FileSystem, FileSystemPathBuf, MemoryFileSystem, OsFileSystem};
+    use ruff_db::vfs::Vfs;
+
+    use crate::resolver::{set_module_resolution_settings, RawModuleResolutionSettings};
+    use crate::supported_py_version::TargetVersion;
+
+    use super::*;
+
+    #[salsa::db(Jar, ruff_db::Jar)]
+    pub(crate) struct TestDb {
+        storage: salsa::Storage<Self>,
+        file_system: TestFileSystem,
+        events: sync::Arc<sync::Mutex<Vec<salsa::Event>>>,
+        vfs: Vfs,
+    }
+
+    impl TestDb {
+        pub(crate) fn new() -> Self {
+            Self {
+                storage: salsa::Storage::default(),
+                file_system: TestFileSystem::Memory(MemoryFileSystem::default()),
+                events: sync::Arc::default(),
+                vfs: Vfs::with_stubbed_vendored(),
+            }
+        }
+
+        /// Returns the memory file system.
+        ///
+        /// ## Panics
+        /// If this test db isn't using a memory file system.
+        pub(crate) fn memory_file_system(&self) -> &MemoryFileSystem {
+            if let TestFileSystem::Memory(fs) = &self.file_system {
+                fs
+            } else {
+                panic!("The test db is not using a memory file system");
+            }
+        }
+
+        /// Uses the real file system instead of the memory file system.
+        ///
+        /// This useful for testing advanced file system features like permissions, symlinks, etc.
+        ///
+        /// Note that any files written to the memory file system won't be copied over.
+        pub(crate) fn with_os_file_system(&mut self) {
+            self.file_system = TestFileSystem::Os(OsFileSystem);
+        }
+
+        #[allow(unused)]
+        pub(crate) fn vfs_mut(&mut self) -> &mut Vfs {
+            &mut self.vfs
+        }
+
+        /// Takes the salsa events.
+        ///
+        /// ## Panics
+        /// If there are any pending salsa snapshots.
+        pub(crate) fn take_salsa_events(&mut self) -> Vec<salsa::Event> {
+            let inner = sync::Arc::get_mut(&mut self.events).expect("no pending salsa snapshots");
+
+            let events = inner.get_mut().unwrap();
+            std::mem::take(&mut *events)
+        }
+
+        /// Clears the salsa events.
+        ///
+        /// ## Panics
+        /// If there are any pending salsa snapshots.
+        pub(crate) fn clear_salsa_events(&mut self) {
+            self.take_salsa_events();
+        }
+    }
+
+    impl Upcast<dyn ruff_db::Db> for TestDb {
+        fn upcast(&self) -> &(dyn ruff_db::Db + 'static) {
+            self
+        }
+    }
+
+    impl ruff_db::Db for TestDb {
+        fn file_system(&self) -> &dyn ruff_db::file_system::FileSystem {
+            self.file_system.inner()
+        }
+
+        fn vfs(&self) -> &ruff_db::vfs::Vfs {
+            &self.vfs
+        }
+    }
+
+    impl Db for TestDb {}
+
+    impl salsa::Database for TestDb {
+        fn salsa_event(&self, event: salsa::Event) {
+            tracing::trace!("event: {:?}", event.debug(self));
+            let mut events = self.events.lock().unwrap();
+            events.push(event);
+        }
+    }
+
+    impl salsa::ParallelDatabase for TestDb {
+        fn snapshot(&self) -> salsa::Snapshot<Self> {
+            salsa::Snapshot::new(Self {
+                storage: self.storage.snapshot(),
+                file_system: self.file_system.snapshot(),
+                events: self.events.clone(),
+                vfs: self.vfs.snapshot(),
+            })
+        }
+    }
+
+    enum TestFileSystem {
+        Memory(MemoryFileSystem),
+        #[allow(unused)]
+        Os(OsFileSystem),
+    }
+
+    impl TestFileSystem {
+        fn inner(&self) -> &dyn FileSystem {
+            match self {
+                Self::Memory(inner) => inner,
+                Self::Os(inner) => inner,
+            }
+        }
+
+        fn snapshot(&self) -> Self {
+            match self {
+                Self::Memory(inner) => Self::Memory(inner.snapshot()),
+                Self::Os(inner) => Self::Os(inner.snapshot()),
+            }
+        }
+    }
+
+    pub(crate) struct TestCaseBuilder {
+        db: TestDb,
+        src: FileSystemPathBuf,
+        custom_typeshed: FileSystemPathBuf,
+        site_packages: FileSystemPathBuf,
+        target_version: Option<TargetVersion>,
+    }
+
+    impl TestCaseBuilder {
+        #[must_use]
+        pub(crate) fn with_target_version(mut self, target_version: TargetVersion) -> Self {
+            self.target_version = Some(target_version);
+            self
+        }
+
+        pub(crate) fn build(self) -> TestCase {
+            let TestCaseBuilder {
+                mut db,
+                src,
+                custom_typeshed,
+                site_packages,
+                target_version,
+            } = self;
+
+            let settings = RawModuleResolutionSettings {
+                target_version: target_version.unwrap_or_default(),
+                extra_paths: vec![],
+                workspace_root: src.clone(),
+                custom_typeshed: Some(custom_typeshed.clone()),
+                site_packages: Some(site_packages.clone()),
+            };
+
+            set_module_resolution_settings(&mut db, settings);
+
+            TestCase {
+                db,
+                src,
+                custom_typeshed,
+                site_packages,
+            }
+        }
+    }
+
+    pub(crate) struct TestCase {
+        pub(crate) db: TestDb,
+        pub(crate) src: FileSystemPathBuf,
+        pub(crate) custom_typeshed: FileSystemPathBuf,
+        pub(crate) site_packages: FileSystemPathBuf,
+    }
+
+    pub(crate) fn create_resolver_builder() -> std::io::Result<TestCaseBuilder> {
+        static VERSIONS_DATA: &str = "\
+        asyncio: 3.8-               # 'Regular' package on py38+
+        asyncio.tasks: 3.9-3.11
+        collections: 3.9-           # 'Regular' package on py39+
+        functools: 3.8-
+        importlib: 3.9-             # Namespace package on py39+
+        xml: 3.8-3.8                # Namespace package on py38 only
+        ";
+
+        let db = TestDb::new();
+
+        let src = FileSystemPathBuf::from("src");
+        let site_packages = FileSystemPathBuf::from("site_packages");
+        let custom_typeshed = FileSystemPathBuf::from("typeshed");
+
+        let fs = db.memory_file_system();
+
+        fs.create_directory_all(&src)?;
+        fs.create_directory_all(&site_packages)?;
+        fs.create_directory_all(&custom_typeshed)?;
+        fs.write_file(custom_typeshed.join("stdlib/VERSIONS"), VERSIONS_DATA)?;
+
+        // Regular package on py38+
+        fs.create_directory_all(custom_typeshed.join("stdlib/asyncio"))?;
+        fs.touch(custom_typeshed.join("stdlib/asyncio/__init__.pyi"))?;
+        fs.write_file(
+            custom_typeshed.join("stdlib/asyncio/tasks.pyi"),
+            "class Task: ...",
+        )?;
+
+        // Regular package on py39+
+        fs.create_directory_all(custom_typeshed.join("stdlib/collections"))?;
+        fs.touch(custom_typeshed.join("stdlib/collections/__init__.pyi"))?;
+
+        // Namespace package on py38 only
+        fs.create_directory_all(custom_typeshed.join("stdlib/xml"))?;
+        fs.touch(custom_typeshed.join("stdlib/xml/etree.pyi"))?;
+
+        // Namespace package on py39+
+        fs.create_directory_all(custom_typeshed.join("stdlib/importlib"))?;
+        fs.touch(custom_typeshed.join("stdlib/importlib/abc.pyi"))?;
+
+        fs.write_file(
+            custom_typeshed.join("stdlib/functools.pyi"),
+            "def update_wrapper(): ...",
+        )?;
+
+        Ok(TestCaseBuilder {
+            db,
+            src,
+            custom_typeshed,
+            site_packages,
+            target_version: None,
+        })
+    }
+}

crates/red_knot_module_resolver/src/lib.rs

@@ -0,0 +1,15 @@
+mod db;
+mod module;
+mod module_name;
+mod path;
+mod resolver;
+mod state;
+mod supported_py_version;
+mod typeshed;
+
+pub use db::{Db, Jar};
+pub use module::{Module, ModuleKind};
+pub use module_name::ModuleName;
+pub use resolver::{resolve_module, set_module_resolution_settings, RawModuleResolutionSettings};
+pub use supported_py_version::TargetVersion;
+pub use typeshed::{TypeshedVersionsParseError, TypeshedVersionsParseErrorKind};

crates/red_knot_module_resolver/src/module.rs

@@ -0,0 +1,91 @@
+use std::fmt::Formatter;
+use std::sync::Arc;
+
+use ruff_db::vfs::VfsFile;
+
+use crate::db::Db;
+use crate::module_name::ModuleName;
+use crate::path::{ModuleResolutionPathBuf, ModuleResolutionPathRef};
+
+/// Representation of a Python module.
+#[derive(Clone, PartialEq, Eq)]
+pub struct Module {
+    inner: Arc<ModuleInner>,
+}
+
+impl Module {
+    pub(crate) fn new(
+        name: ModuleName,
+        kind: ModuleKind,
+        search_path: Arc<ModuleResolutionPathBuf>,
+        file: VfsFile,
+    ) -> Self {
+        Self {
+            inner: Arc::new(ModuleInner {
+                name,
+                kind,
+                search_path,
+                file,
+            }),
+        }
+    }
+
+    /// The absolute name of the module (e.g. `foo.bar`)
+    pub fn name(&self) -> &ModuleName {
+        &self.inner.name
+    }
+
+    /// The file to the source code that defines this module
+    pub fn file(&self) -> VfsFile {
+        self.inner.file
+    }
+
+    /// The search path from which the module was resolved.
+    pub(crate) fn search_path(&self) -> ModuleResolutionPathRef {
+        ModuleResolutionPathRef::from(&*self.inner.search_path)
+    }
+
+    /// Determine whether this module is a single-file module or a package
+    pub fn kind(&self) -> ModuleKind {
+        self.inner.kind
+    }
+}
+
+impl std::fmt::Debug for Module {
+    fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
+        f.debug_struct("Module")
+            .field("name", &self.name())
+            .field("kind", &self.kind())
+            .field("file", &self.file())
+            .field("search_path", &self.search_path())
+            .finish()
+    }
+}
+
+impl salsa::DebugWithDb<dyn Db> for Module {
+    fn fmt(&self, f: &mut Formatter<'_>, db: &dyn Db) -> std::fmt::Result {
+        f.debug_struct("Module")
+            .field("name", &self.name())
+            .field("kind", &self.kind())
+            .field("file", &self.file().debug(db.upcast()))
+            .field("search_path", &self.search_path())
+            .finish()
+    }
+}
+
+#[derive(PartialEq, Eq)]
+struct ModuleInner {
+    name: ModuleName,
+    kind: ModuleKind,
+    search_path: Arc<ModuleResolutionPathBuf>,
+    file: VfsFile,
+}
+
+#[derive(Copy, Clone, Debug, Eq, PartialEq, Hash)]
+pub enum ModuleKind {
+    /// A single-file module (e.g. `foo.py` or `foo.pyi`)
+    Module,
+
+    /// A python package (`foo/__init__.py` or `foo/__init__.pyi`)
+    Package,
+}

crates/red_knot_module_resolver/src/module_name.rs

@@ -1,15 +1,10 @@
 use std::fmt;
-use std::num::NonZeroU32;
 use std::ops::Deref;
 
 use compact_str::{CompactString, ToCompactString};
 
-use ruff_db::files::File;
-use ruff_python_ast as ast;
 use ruff_python_stdlib::identifiers::is_identifier;
 
-use crate::{db::Db, module_resolver::file_to_module};
-
 /// A module name, e.g. `foo.bar`.
 ///
 /// Always normalized to the absolute form (never a relative module name, i.e., never `.foo`).
@@ -47,7 +42,7 @@ impl ModuleName {
     /// ## Examples
     ///
     /// ```
-    /// use red_knot_python_semantic::ModuleName;
+    /// use red_knot_module_resolver::ModuleName;
     ///
     /// assert_eq!(ModuleName::new_static("foo.bar").as_deref(), Some("foo.bar"));
     /// assert_eq!(ModuleName::new_static(""), None);
@@ -60,7 +55,8 @@ impl ModuleName {
     #[inline]
     #[must_use]
     pub fn new_static(name: &'static str) -> Option<Self> {
-        Self::is_valid_name(name).then(|| Self(CompactString::const_new(name)))
+        // TODO(Micha): Use CompactString::const_new once we upgrade to 0.8 https://github.com/ParkMyCar/compact_str/pull/336
+        Self::is_valid_name(name).then(|| Self(CompactString::from(name)))
     }
 
     #[must_use]
@@ -73,7 +69,7 @@ impl ModuleName {
     /// # Examples
     ///
     /// ```
-    /// use red_knot_python_semantic::ModuleName;
+    /// use red_knot_module_resolver::ModuleName;
     ///
     /// assert_eq!(ModuleName::new_static("foo.bar.baz").unwrap().components().collect::<Vec<_>>(), vec!["foo", "bar", "baz"]);
     /// ```
@@ -87,7 +83,7 @@ impl ModuleName {
     /// # Examples
     ///
     /// ```
-    /// use red_knot_python_semantic::ModuleName;
+    /// use red_knot_module_resolver::ModuleName;
     ///
     /// assert_eq!(ModuleName::new_static("foo.bar").unwrap().parent(), Some(ModuleName::new_static("foo").unwrap()));
     /// assert_eq!(ModuleName::new_static("foo.bar.baz").unwrap().parent(), Some(ModuleName::new_static("foo.bar").unwrap()));
@@ -106,7 +102,7 @@ impl ModuleName {
     /// # Examples
     ///
     /// ```
-    /// use red_knot_python_semantic::ModuleName;
+    /// use red_knot_module_resolver::ModuleName;
     ///
     /// assert!(ModuleName::new_static("foo.bar").unwrap().starts_with(&ModuleName::new_static("foo").unwrap()));
     ///
@@ -138,7 +134,7 @@ impl ModuleName {
     /// # Examples
     ///
     /// ```
-    /// use red_knot_python_semantic::ModuleName;
+    /// use red_knot_module_resolver::ModuleName;
     ///
     /// assert_eq!(&*ModuleName::from_components(["a"]).unwrap(), "a");
     /// assert_eq!(&*ModuleName::from_components(["a", "b"]).unwrap(), "a.b");
@@ -173,67 +169,6 @@ impl ModuleName {
         };
         Some(Self(name))
     }
-
-    /// Extend `self` with the components of `other`
-    ///
-    /// # Examples
-    ///
-    /// ```
-    /// use red_knot_python_semantic::ModuleName;
-    ///
-    /// let mut module_name = ModuleName::new_static("foo").unwrap();
-    /// module_name.extend(&ModuleName::new_static("bar").unwrap());
-    /// assert_eq!(&module_name, "foo.bar");
-    /// module_name.extend(&ModuleName::new_static("baz.eggs.ham").unwrap());
-    /// assert_eq!(&module_name, "foo.bar.baz.eggs.ham");
-    /// ```
-    pub fn extend(&mut self, other: &ModuleName) {
-        self.0.push('.');
-        self.0.push_str(other);
-    }
-
-    /// Returns an iterator of this module name and all of its parent modules.
-    ///
-    /// # Examples
-    ///
-    /// ```
-    /// use red_knot_python_semantic::ModuleName;
-    ///
-    /// assert_eq!(
-    ///     ModuleName::new_static("foo.bar.baz").unwrap().ancestors().collect::<Vec<_>>(),
-    ///     vec![
-    ///         ModuleName::new_static("foo.bar.baz").unwrap(),
-    ///         ModuleName::new_static("foo.bar").unwrap(),
-    ///         ModuleName::new_static("foo").unwrap(),
-    ///     ],
-    /// );
-    /// ```
-    pub fn ancestors(&self) -> impl Iterator<Item = Self> {
-        std::iter::successors(Some(self.clone()), Self::parent)
-    }
-
-    pub(crate) fn from_import_statement<'db>(
-        db: &'db dyn Db,
-        importing_file: File,
-        node: &'db ast::StmtImportFrom,
-    ) -> Result<Self, ModuleNameResolutionError> {
-        let ast::StmtImportFrom {
-            module,
-            level,
-            names: _,
-            range: _,
-        } = node;
-
-        let module = module.as_deref();
-
-        if let Some(level) = NonZeroU32::new(*level) {
-            relative_module_name(db, importing_file, module, level)
-        } else {
-            module
-                .and_then(Self::new)
-                .ok_or(ModuleNameResolutionError::InvalidSyntax)
-        }
-    }
 }
 
 impl Deref for ModuleName {
@@ -262,58 +197,3 @@ impl std::fmt::Display for ModuleName {
         f.write_str(&self.0)
     }
 }
-
-/// Given a `from .foo import bar` relative import, resolve the relative module
-/// we're importing `bar` from into an absolute [`ModuleName`]
-/// using the name of the module we're currently analyzing.
-///
-/// - `level` is the number of dots at the beginning of the relative module name:
-///   - `from .foo.bar import baz` => `level == 1`
-///   - `from ...foo.bar import baz` => `level == 3`
-/// - `tail` is the relative module name stripped of all leading dots:
-///   - `from .foo import bar` => `tail == "foo"`
-///   - `from ..foo.bar import baz` => `tail == "foo.bar"`
-fn relative_module_name(
-    db: &dyn Db,
-    importing_file: File,
-    tail: Option<&str>,
-    level: NonZeroU32,
-) -> Result<ModuleName, ModuleNameResolutionError> {
-    let module = file_to_module(db, importing_file)
-        .ok_or(ModuleNameResolutionError::UnknownCurrentModule)?;
-    let mut level = level.get();
-
-    if module.kind().is_package() {
-        level = level.saturating_sub(1);
-    }
-
-    let mut module_name = module
-        .name()
-        .ancestors()
-        .nth(level as usize)
-        .ok_or(ModuleNameResolutionError::TooManyDots)?;
-
-    if let Some(tail) = tail {
-        let tail = ModuleName::new(tail).ok_or(ModuleNameResolutionError::InvalidSyntax)?;
-        module_name.extend(&tail);
-    }
-
-    Ok(module_name)
-}
-
-/// Various ways in which resolving a [`ModuleName`]
-/// from an [`ast::StmtImport`] or [`ast::StmtImportFrom`] node might fail
-#[derive(Debug, Copy, Clone, PartialEq, Eq)]
-pub(crate) enum ModuleNameResolutionError {
-    /// The import statement has invalid syntax
-    InvalidSyntax,
-
-    /// We couldn't resolve the file we're currently analyzing back to a module
-    /// (Only necessary for relative import statements)
-    UnknownCurrentModule,
-
-    /// The relative import statement seems to take us outside of the module search path
-    /// (e.g. our current module is `foo.bar`, and the relative import statement in `foo.bar`
-    /// is `from ....baz import spam`)
-    TooManyDots,
-}

crates/red_knot_module_resolver/src/path.rs

@@ -0,0 +1,997 @@
+/// Internal abstractions for differentiating between different kinds of search paths.
+///
+/// TODO(Alex): Should we use different types for absolute vs relative paths?
+/// <https://github.com/astral-sh/ruff/pull/12141#discussion_r1667010245>
+use std::fmt;
+
+use ruff_db::file_system::{FileSystemPath, FileSystemPathBuf};
+use ruff_db::vfs::{system_path_to_file, VfsFile};
+
+use crate::module_name::ModuleName;
+use crate::state::ResolverState;
+use crate::typeshed::TypeshedVersionsQueryResult;
+
+/// Enumeration of the different kinds of search paths type checkers are expected to support.
+///
+/// N.B. Although we don't implement `Ord` for this enum, they are ordered in terms of the
+/// priority that we want to give these modules when resolving them,
+/// as per [the order given in the typing spec]
+///
+/// [the order given in the typing spec]: https://typing.readthedocs.io/en/latest/spec/distributing.html#import-resolution-ordering
+#[derive(Debug, Clone, PartialEq, Eq, Hash)]
+enum ModuleResolutionPathBufInner {
+    Extra(FileSystemPathBuf),
+    FirstParty(FileSystemPathBuf),
+    StandardLibrary(FileSystemPathBuf),
+    SitePackages(FileSystemPathBuf),
+}
+
+impl ModuleResolutionPathBufInner {
+    fn push(&mut self, component: &str) {
+        let extension = camino::Utf8Path::new(component).extension();
+        let inner = match self {
+            Self::Extra(ref mut path) => {
+                if let Some(extension) = extension {
+                    assert!(
+                        matches!(extension, "pyi" | "py"),
+                        "Extension must be `py` or `pyi`; got `{extension}`"
+                    );
+                }
+                path
+            }
+            Self::FirstParty(ref mut path) => {
+                if let Some(extension) = extension {
+                    assert!(
+                        matches!(extension, "pyi" | "py"),
+                        "Extension must be `py` or `pyi`; got `{extension}`"
+                    );
+                }
+                path
+            }
+            Self::StandardLibrary(ref mut path) => {
+                if let Some(extension) = extension {
+                    assert_eq!(
+                        extension, "pyi",
+                        "Extension must be `pyi`; got `{extension}`"
+                    );
+                }
+                path
+            }
+            Self::SitePackages(ref mut path) => {
+                if let Some(extension) = extension {
+                    assert!(
+                        matches!(extension, "pyi" | "py"),
+                        "Extension must be `py` or `pyi`; got `{extension}`"
+                    );
+                }
+                path
+            }
+        };
+        assert!(
+            inner.extension().is_none(),
+            "Cannot push part {component} to {inner}, which already has an extension"
+        );
+        inner.push(component);
+    }
+}
+
+#[derive(Clone, PartialEq, Eq, Hash)]
+pub(crate) struct ModuleResolutionPathBuf(ModuleResolutionPathBufInner);
+
+impl ModuleResolutionPathBuf {
+    /// Push a new part to the path,
+    /// while maintaining the invariant that the path can only have `.py` or `.pyi` extensions.
+    /// For the stdlib variant specifically, it may only have a `.pyi` extension.
+    ///
+    /// ## Panics:
+    /// If a component with an invalid extension is passed
+    pub(crate) fn push(&mut self, component: &str) {
+        self.0.push(component);
+    }
+
+    #[must_use]
+    pub(crate) fn extra(path: impl Into<FileSystemPathBuf>) -> Option<Self> {
+        let path = path.into();
+        path.extension()
+            .map_or(true, |ext| matches!(ext, "py" | "pyi"))
+            .then_some(Self(ModuleResolutionPathBufInner::Extra(path)))
+    }
+
+    #[must_use]
+    pub(crate) fn first_party(path: impl Into<FileSystemPathBuf>) -> Option<Self> {
+        let path = path.into();
+        path.extension()
+            .map_or(true, |ext| matches!(ext, "pyi" | "py"))
+            .then_some(Self(ModuleResolutionPathBufInner::FirstParty(path)))
+    }
+
+    #[must_use]
+    pub(crate) fn standard_library(path: impl Into<FileSystemPathBuf>) -> Option<Self> {
+        let path = path.into();
+        path.extension()
+            .map_or(true, |ext| ext == "pyi")
+            .then_some(Self(ModuleResolutionPathBufInner::StandardLibrary(path)))
+    }
+
+    #[must_use]
+    pub(crate) fn stdlib_from_typeshed_root(typeshed_root: &FileSystemPath) -> Option<Self> {
+        Self::standard_library(typeshed_root.join(FileSystemPath::new("stdlib")))
+    }
+
+    #[must_use]
+    pub(crate) fn site_packages(path: impl Into<FileSystemPathBuf>) -> Option<Self> {
+        let path = path.into();
+        path.extension()
+            .map_or(true, |ext| matches!(ext, "pyi" | "py"))
+            .then_some(Self(ModuleResolutionPathBufInner::SitePackages(path)))
+    }
+
+    #[must_use]
+    pub(crate) fn is_regular_package(&self, search_path: &Self, resolver: &ResolverState) -> bool {
+        ModuleResolutionPathRef::from(self).is_regular_package(search_path, resolver)
+    }
+
+    #[must_use]
+    pub(crate) fn is_directory(&self, search_path: &Self, resolver: &ResolverState) -> bool {
+        ModuleResolutionPathRef::from(self).is_directory(search_path, resolver)
+    }
+
+    #[must_use]
+    pub(crate) fn with_pyi_extension(&self) -> Self {
+        ModuleResolutionPathRef::from(self).with_pyi_extension()
+    }
+
+    #[must_use]
+    pub(crate) fn with_py_extension(&self) -> Option<Self> {
+        ModuleResolutionPathRef::from(self).with_py_extension()
+    }
+
+    #[must_use]
+    pub(crate) fn relativize_path<'a>(
+        &'a self,
+        absolute_path: &'a (impl AsRef<FileSystemPath> + ?Sized),
+    ) -> Option<ModuleResolutionPathRef<'a>> {
+        ModuleResolutionPathRef::from(self).relativize_path(absolute_path.as_ref())
+    }
+
+    /// Returns `None` if the path doesn't exist, isn't accessible, or if the path points to a directory.
+    pub(crate) fn to_vfs_file(
+        &self,
+        search_path: &Self,
+        resolver: &ResolverState,
+    ) -> Option<VfsFile> {
+        ModuleResolutionPathRef::from(self).to_vfs_file(search_path, resolver)
+    }
+}
+
+impl fmt::Debug for ModuleResolutionPathBuf {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        let (name, path) = match &self.0 {
+            ModuleResolutionPathBufInner::Extra(path) => ("Extra", path),
+            ModuleResolutionPathBufInner::FirstParty(path) => ("FirstParty", path),
+            ModuleResolutionPathBufInner::SitePackages(path) => ("SitePackages", path),
+            ModuleResolutionPathBufInner::StandardLibrary(path) => ("StandardLibrary", path),
+        };
+        f.debug_tuple(&format!("ModuleResolutionPathBuf::{name}"))
+            .field(path)
+            .finish()
+    }
+}
+
+#[derive(Debug, PartialEq, Eq, Hash, Clone, Copy)]
+enum ModuleResolutionPathRefInner<'a> {
+    Extra(&'a FileSystemPath),
+    FirstParty(&'a FileSystemPath),
+    StandardLibrary(&'a FileSystemPath),
+    SitePackages(&'a FileSystemPath),
+}
+
+impl<'a> ModuleResolutionPathRefInner<'a> {
+    #[must_use]
+    fn query_stdlib_version<'db>(
+        module_path: &'a FileSystemPath,
+        stdlib_search_path: Self,
+        stdlib_root: &FileSystemPath,
+        resolver_state: &ResolverState<'db>,
+    ) -> TypeshedVersionsQueryResult {
+        let Some(module_name) = stdlib_search_path
+            .relativize_path(module_path)
+            .and_then(Self::to_module_name)
+        else {
+            return TypeshedVersionsQueryResult::DoesNotExist;
+        };
+        let ResolverState {
+            db,
+            typeshed_versions,
+            target_version,
+        } = resolver_state;
+        typeshed_versions.query_module(&module_name, *db, stdlib_root, *target_version)
+    }
+
+    #[must_use]
+    fn is_directory(&self, search_path: Self, resolver: &ResolverState) -> bool {
+        match (self, search_path) {
+            (Self::Extra(path), Self::Extra(_)) => resolver.file_system().is_directory(path),
+            (Self::FirstParty(path), Self::FirstParty(_)) => resolver.file_system().is_directory(path),
+            (Self::SitePackages(path), Self::SitePackages(_)) => resolver.file_system().is_directory(path),
+            (Self::StandardLibrary(path), Self::StandardLibrary(stdlib_root)) => {
+                match Self::query_stdlib_version( path, search_path, stdlib_root, resolver) {
+                    TypeshedVersionsQueryResult::DoesNotExist => false,
+                    TypeshedVersionsQueryResult::Exists => resolver.file_system().is_directory(path),
+                    TypeshedVersionsQueryResult::MaybeExists => resolver.file_system().is_directory(path),
+                }
+            }
+            (path, root) => unreachable!(
+                "The search path should always be the same variant as `self` (got: {path:?}, {root:?})"
+            )
+        }
+    }
+
+    #[must_use]
+    fn is_regular_package(&self, search_path: Self, resolver: &ResolverState) -> bool {
+        fn is_non_stdlib_pkg(state: &ResolverState, path: &FileSystemPath) -> bool {
+            let file_system = state.file_system();
+            file_system.exists(&path.join("__init__.py"))
+                || file_system.exists(&path.join("__init__.pyi"))
+        }
+
+        match (self, search_path) {
+            (Self::Extra(path), Self::Extra(_)) => is_non_stdlib_pkg(resolver, path),
+            (Self::FirstParty(path), Self::FirstParty(_)) => is_non_stdlib_pkg(resolver, path),
+            (Self::SitePackages(path), Self::SitePackages(_)) => is_non_stdlib_pkg(resolver, path),
+            // Unlike the other variants:
+            // (1) Account for VERSIONS
+            // (2) Only test for `__init__.pyi`, not `__init__.py`
+            (Self::StandardLibrary(path), Self::StandardLibrary(stdlib_root)) => {
+                match Self::query_stdlib_version( path, search_path, stdlib_root, resolver) {
+                    TypeshedVersionsQueryResult::DoesNotExist => false,
+                    TypeshedVersionsQueryResult::Exists => resolver.db.file_system().exists(&path.join("__init__.pyi")),
+                    TypeshedVersionsQueryResult::MaybeExists => resolver.db.file_system().exists(&path.join("__init__.pyi")),
+                }
+            }
+            (path, root) => unreachable!(
+                "The search path should always be the same variant as `self` (got: {path:?}, {root:?})"
+            )
+        }
+    }
+
+    fn to_vfs_file(self, search_path: Self, resolver: &ResolverState) -> Option<VfsFile> {
+        match (self, search_path) {
+            (Self::Extra(path), Self::Extra(_)) => system_path_to_file(resolver.db.upcast(), path),
+            (Self::FirstParty(path), Self::FirstParty(_)) => system_path_to_file(resolver.db.upcast(), path),
+            (Self::SitePackages(path), Self::SitePackages(_)) => {
+                system_path_to_file(resolver.db.upcast(), path)
+            }
+            (Self::StandardLibrary(path), Self::StandardLibrary(stdlib_root)) => {
+                match Self::query_stdlib_version(path, search_path, stdlib_root, resolver) {
+                    TypeshedVersionsQueryResult::DoesNotExist => None,
+                    TypeshedVersionsQueryResult::Exists => system_path_to_file(resolver.db.upcast(), path),
+                    TypeshedVersionsQueryResult::MaybeExists => system_path_to_file(resolver.db.upcast(), path)
+                }
+            }
+            (path, root) => unreachable!(
+                "The search path should always be the same variant as `self` (got: {path:?}, {root:?})"
+            )
+        }
+    }
+
+    #[must_use]
+    fn to_module_name(self) -> Option<ModuleName> {
+        let (fs_path, skip_final_part) = match self {
+            Self::Extra(path) | Self::FirstParty(path) | Self::SitePackages(path) => (
+                path,
+                path.ends_with("__init__.py") || path.ends_with("__init__.pyi"),
+            ),
+            Self::StandardLibrary(path) => (path, path.ends_with("__init__.pyi")),
+        };
+
+        let parent_components = fs_path
+            .parent()?
+            .components()
+            .map(|component| component.as_str());
+
+        if skip_final_part {
+            ModuleName::from_components(parent_components)
+        } else {
+            ModuleName::from_components(parent_components.chain(fs_path.file_stem()))
+        }
+    }
+
+    #[must_use]
+    fn with_pyi_extension(&self) -> ModuleResolutionPathBufInner {
+        match self {
+            Self::Extra(path) => ModuleResolutionPathBufInner::Extra(path.with_extension("pyi")),
+            Self::FirstParty(path) => {
+                ModuleResolutionPathBufInner::FirstParty(path.with_extension("pyi"))
+            }
+            Self::StandardLibrary(path) => {
+                ModuleResolutionPathBufInner::StandardLibrary(path.with_extension("pyi"))
+            }
+            Self::SitePackages(path) => {
+                ModuleResolutionPathBufInner::SitePackages(path.with_extension("pyi"))
+            }
+        }
+    }
+
+    #[must_use]
+    fn with_py_extension(&self) -> Option<ModuleResolutionPathBufInner> {
+        match self {
+            Self::Extra(path) => Some(ModuleResolutionPathBufInner::Extra(
+                path.with_extension("py"),
+            )),
+            Self::FirstParty(path) => Some(ModuleResolutionPathBufInner::FirstParty(
+                path.with_extension("py"),
+            )),
+            Self::StandardLibrary(_) => None,
+            Self::SitePackages(path) => Some(ModuleResolutionPathBufInner::SitePackages(
+                path.with_extension("py"),
+            )),
+        }
+    }
+
+    #[must_use]
+    fn relativize_path(&self, absolute_path: &'a FileSystemPath) -> Option<Self> {
+        match self {
+            Self::Extra(root) => absolute_path.strip_prefix(root).ok().and_then(|path| {
+                path.extension()
+                    .map_or(true, |ext| matches!(ext, "py" | "pyi"))
+                    .then_some(Self::Extra(path))
+            }),
+            Self::FirstParty(root) => absolute_path.strip_prefix(root).ok().and_then(|path| {
+                path.extension()
+                    .map_or(true, |ext| matches!(ext, "pyi" | "py"))
+                    .then_some(Self::FirstParty(path))
+            }),
+            Self::StandardLibrary(root) => absolute_path.strip_prefix(root).ok().and_then(|path| {
+                path.extension()
+                    .map_or(true, |ext| ext == "pyi")
+                    .then_some(Self::StandardLibrary(path))
+            }),
+            Self::SitePackages(root) => absolute_path.strip_prefix(root).ok().and_then(|path| {
+                path.extension()
+                    .map_or(true, |ext| matches!(ext, "pyi" | "py"))
+                    .then_some(Self::SitePackages(path))
+            }),
+        }
+    }
+}
+
+#[derive(Clone, Copy, PartialEq, Eq)]
+pub(crate) struct ModuleResolutionPathRef<'a>(ModuleResolutionPathRefInner<'a>);
+
+impl<'a> ModuleResolutionPathRef<'a> {
+    #[must_use]
+    pub(crate) fn is_directory(
+        &self,
+        search_path: impl Into<Self>,
+        resolver: &ResolverState,
+    ) -> bool {
+        self.0.is_directory(search_path.into().0, resolver)
+    }
+
+    #[must_use]
+    pub(crate) fn is_regular_package(
+        &self,
+        search_path: impl Into<Self>,
+        resolver: &ResolverState,
+    ) -> bool {
+        self.0.is_regular_package(search_path.into().0, resolver)
+    }
+
+    #[must_use]
+    pub(crate) fn to_vfs_file(
+        self,
+        search_path: impl Into<Self>,
+        resolver: &ResolverState,
+    ) -> Option<VfsFile> {
+        self.0.to_vfs_file(search_path.into().0, resolver)
+    }
+
+    #[must_use]
+    pub(crate) fn to_module_name(self) -> Option<ModuleName> {
+        self.0.to_module_name()
+    }
+
+    #[must_use]
+    pub(crate) fn with_pyi_extension(&self) -> ModuleResolutionPathBuf {
+        ModuleResolutionPathBuf(self.0.with_pyi_extension())
+    }
+
+    #[must_use]
+    pub(crate) fn with_py_extension(self) -> Option<ModuleResolutionPathBuf> {
+        self.0.with_py_extension().map(ModuleResolutionPathBuf)
+    }
+
+    #[must_use]
+    pub(crate) fn relativize_path(&self, absolute_path: &'a FileSystemPath) -> Option<Self> {
+        self.0.relativize_path(absolute_path).map(Self)
+    }
+}
+
+impl fmt::Debug for ModuleResolutionPathRef<'_> {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        let (name, path) = match &self.0 {
+            ModuleResolutionPathRefInner::Extra(path) => ("Extra", path),
+            ModuleResolutionPathRefInner::FirstParty(path) => ("FirstParty", path),
+            ModuleResolutionPathRefInner::SitePackages(path) => ("SitePackages", path),
+            ModuleResolutionPathRefInner::StandardLibrary(path) => ("StandardLibrary", path),
+        };
+        f.debug_tuple(&format!("ModuleResolutionPathRef::{name}"))
+            .field(path)
+            .finish()
+    }
+}
+
+impl<'a> From<&'a ModuleResolutionPathBuf> for ModuleResolutionPathRef<'a> {
+    fn from(value: &'a ModuleResolutionPathBuf) -> Self {
+        let inner = match &value.0 {
+            ModuleResolutionPathBufInner::Extra(path) => ModuleResolutionPathRefInner::Extra(path),
+            ModuleResolutionPathBufInner::FirstParty(path) => {
+                ModuleResolutionPathRefInner::FirstParty(path)
+            }
+            ModuleResolutionPathBufInner::StandardLibrary(path) => {
+                ModuleResolutionPathRefInner::StandardLibrary(path)
+            }
+            ModuleResolutionPathBufInner::SitePackages(path) => {
+                ModuleResolutionPathRefInner::SitePackages(path)
+            }
+        };
+        ModuleResolutionPathRef(inner)
+    }
+}
+
+impl PartialEq<FileSystemPath> for ModuleResolutionPathRef<'_> {
+    fn eq(&self, other: &FileSystemPath) -> bool {
+        let fs_path = match self.0 {
+            ModuleResolutionPathRefInner::Extra(path) => path,
+            ModuleResolutionPathRefInner::FirstParty(path) => path,
+            ModuleResolutionPathRefInner::SitePackages(path) => path,
+            ModuleResolutionPathRefInner::StandardLibrary(path) => path,
+        };
+        fs_path == other
+    }
+}
+
+impl PartialEq<ModuleResolutionPathRef<'_>> for FileSystemPath {
+    fn eq(&self, other: &ModuleResolutionPathRef) -> bool {
+        other == self
+    }
+}
+
+impl PartialEq<FileSystemPathBuf> for ModuleResolutionPathRef<'_> {
+    fn eq(&self, other: &FileSystemPathBuf) -> bool {
+        self == &**other
+    }
+}
+
+impl PartialEq<ModuleResolutionPathRef<'_>> for FileSystemPathBuf {
+    fn eq(&self, other: &ModuleResolutionPathRef<'_>) -> bool {
+        &**self == other
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use insta::assert_debug_snapshot;
+
+    use crate::db::tests::{create_resolver_builder, TestCase, TestDb};
+    use crate::supported_py_version::TargetVersion;
+    use crate::typeshed::LazyTypeshedVersions;
+
+    use super::*;
+
+    impl ModuleResolutionPathBuf {
+        #[must_use]
+        pub(crate) fn join(&self, component: &str) -> Self {
+            ModuleResolutionPathRef::from(self).join(component)
+        }
+    }
+
+    impl<'a> ModuleResolutionPathRef<'a> {
+        #[must_use]
+        fn join(
+            &self,
+            component: &'a (impl AsRef<FileSystemPath> + ?Sized),
+        ) -> ModuleResolutionPathBuf {
+            let mut result = self.to_path_buf();
+            result.push(component.as_ref().as_str());
+            result
+        }
+
+        #[must_use]
+        pub(crate) fn to_path_buf(self) -> ModuleResolutionPathBuf {
+            let inner = match self.0 {
+                ModuleResolutionPathRefInner::Extra(path) => {
+                    ModuleResolutionPathBufInner::Extra(path.to_path_buf())
+                }
+                ModuleResolutionPathRefInner::FirstParty(path) => {
+                    ModuleResolutionPathBufInner::FirstParty(path.to_path_buf())
+                }
+                ModuleResolutionPathRefInner::StandardLibrary(path) => {
+                    ModuleResolutionPathBufInner::StandardLibrary(path.to_path_buf())
+                }
+                ModuleResolutionPathRefInner::SitePackages(path) => {
+                    ModuleResolutionPathBufInner::SitePackages(path.to_path_buf())
+                }
+            };
+            ModuleResolutionPathBuf(inner)
+        }
+
+        #[must_use]
+        pub(crate) const fn is_stdlib_search_path(&self) -> bool {
+            matches!(&self.0, ModuleResolutionPathRefInner::StandardLibrary(_))
+        }
+    }
+
+    #[test]
+    fn constructor_rejects_non_pyi_stdlib_paths() {
+        assert_eq!(ModuleResolutionPathBuf::standard_library("foo.py"), None);
+        assert_eq!(
+            ModuleResolutionPathBuf::standard_library("foo/__init__.py"),
+            None
+        );
+    }
+
+    #[test]
+    fn path_buf_debug_impl() {
+        assert_debug_snapshot!(
+            ModuleResolutionPathBuf::standard_library("foo/bar.pyi").unwrap(),
+            @r###"
+        ModuleResolutionPathBuf::StandardLibrary(
+            "foo/bar.pyi",
+        )
+        "###
+        );
+    }
+
+    #[test]
+    fn path_ref_debug_impl() {
+        assert_debug_snapshot!(
+            ModuleResolutionPathRef(ModuleResolutionPathRefInner::Extra(FileSystemPath::new("foo/bar.py"))),
+            @r###"
+        ModuleResolutionPathRef::Extra(
+            "foo/bar.py",
+        )
+        "###
+        );
+    }
+
+    #[test]
+    fn with_extension_methods() {
+        assert_eq!(
+            ModuleResolutionPathBuf::standard_library("foo")
+                .unwrap()
+                .with_py_extension(),
+            None
+        );
+
+        assert_eq!(
+            ModuleResolutionPathBuf::standard_library("foo")
+                .unwrap()
+                .with_pyi_extension(),
+            ModuleResolutionPathBuf(ModuleResolutionPathBufInner::StandardLibrary(
+                FileSystemPathBuf::from("foo.pyi")
+            ))
+        );
+
+        assert_eq!(
+            ModuleResolutionPathBuf::first_party("foo/bar")
+                .unwrap()
+                .with_py_extension()
+                .unwrap(),
+            ModuleResolutionPathBuf(ModuleResolutionPathBufInner::FirstParty(
+                FileSystemPathBuf::from("foo/bar.py")
+            ))
+        );
+    }
+
+    #[test]
+    fn module_name_1_part() {
+        assert_eq!(
+            ModuleResolutionPathRef(ModuleResolutionPathRefInner::Extra(FileSystemPath::new(
+                "foo"
+            )))
+            .to_module_name(),
+            ModuleName::new_static("foo")
+        );
+
+        assert_eq!(
+            ModuleResolutionPathRef(ModuleResolutionPathRefInner::StandardLibrary(
+                FileSystemPath::new("foo.pyi")
+            ))
+            .to_module_name(),
+            ModuleName::new_static("foo")
+        );
+
+        assert_eq!(
+            ModuleResolutionPathRef(ModuleResolutionPathRefInner::FirstParty(
+                FileSystemPath::new("foo/__init__.py")
+            ))
+            .to_module_name(),
+            ModuleName::new_static("foo")
+        );
+    }
+
+    #[test]
+    fn module_name_2_parts() {
+        assert_eq!(
+            ModuleResolutionPathRef(ModuleResolutionPathRefInner::StandardLibrary(
+                FileSystemPath::new("foo/bar")
+            ))
+            .to_module_name(),
+            ModuleName::new_static("foo.bar")
+        );
+
+        assert_eq!(
+            ModuleResolutionPathRef(ModuleResolutionPathRefInner::Extra(FileSystemPath::new(
+                "foo/bar.pyi"
+            )))
+            .to_module_name(),
+            ModuleName::new_static("foo.bar")
+        );
+
+        assert_eq!(
+            ModuleResolutionPathRef(ModuleResolutionPathRefInner::SitePackages(
+                FileSystemPath::new("foo/bar/__init__.pyi")
+            ))
+            .to_module_name(),
+            ModuleName::new_static("foo.bar")
+        );
+    }
+
+    #[test]
+    fn module_name_3_parts() {
+        assert_eq!(
+            ModuleResolutionPathRef(ModuleResolutionPathRefInner::SitePackages(
+                FileSystemPath::new("foo/bar/__init__.pyi")
+            ))
+            .to_module_name(),
+            ModuleName::new_static("foo.bar")
+        );
+
+        assert_eq!(
+            ModuleResolutionPathRef(ModuleResolutionPathRefInner::SitePackages(
+                FileSystemPath::new("foo/bar/baz")
+            ))
+            .to_module_name(),
+            ModuleName::new_static("foo.bar.baz")
+        );
+    }
+
+    #[test]
+    fn join() {
+        assert_eq!(
+            ModuleResolutionPathBuf::standard_library("foo")
+                .unwrap()
+                .join("bar"),
+            ModuleResolutionPathBuf(ModuleResolutionPathBufInner::StandardLibrary(
+                FileSystemPathBuf::from("foo/bar")
+            ))
+        );
+        assert_eq!(
+            ModuleResolutionPathBuf::standard_library("foo")
+                .unwrap()
+                .join("bar.pyi"),
+            ModuleResolutionPathBuf(ModuleResolutionPathBufInner::StandardLibrary(
+                FileSystemPathBuf::from("foo/bar.pyi")
+            ))
+        );
+        assert_eq!(
+            ModuleResolutionPathBuf::extra("foo")
+                .unwrap()
+                .join("bar.py"),
+            ModuleResolutionPathBuf(ModuleResolutionPathBufInner::Extra(
+                FileSystemPathBuf::from("foo/bar.py")
+            ))
+        );
+    }
+
+    #[test]
+    #[should_panic(expected = "Extension must be `pyi`; got `py`")]
+    fn stdlib_path_invalid_join_py() {
+        ModuleResolutionPathBuf::standard_library("foo")
+            .unwrap()
+            .push("bar.py");
+    }
+
+    #[test]
+    #[should_panic(expected = "Extension must be `pyi`; got `rs`")]
+    fn stdlib_path_invalid_join_rs() {
+        ModuleResolutionPathBuf::standard_library("foo")
+            .unwrap()
+            .push("bar.rs");
+    }
+
+    #[test]
+    #[should_panic(expected = "Extension must be `py` or `pyi`; got `rs`")]
+    fn non_stdlib_path_invalid_join_rs() {
+        ModuleResolutionPathBuf::site_packages("foo")
+            .unwrap()
+            .push("bar.rs");
+    }
+
+    #[test]
+    #[should_panic(expected = "already has an extension")]
+    fn invalid_stdlib_join_too_many_extensions() {
+        ModuleResolutionPathBuf::standard_library("foo.pyi")
+            .unwrap()
+            .push("bar.pyi");
+    }
+
+    #[test]
+    fn relativize_stdlib_path_errors() {
+        let root = ModuleResolutionPathBuf::standard_library("foo/stdlib").unwrap();
+
+        // Must have a `.pyi` extension or no extension:
+        let bad_absolute_path = FileSystemPath::new("foo/stdlib/x.py");
+        assert_eq!(root.relativize_path(bad_absolute_path), None);
+        let second_bad_absolute_path = FileSystemPath::new("foo/stdlib/x.rs");
+        assert_eq!(root.relativize_path(second_bad_absolute_path), None);
+
+        // Must be a path that is a child of `root`:
+        let third_bad_absolute_path = FileSystemPath::new("bar/stdlib/x.pyi");
+        assert_eq!(root.relativize_path(third_bad_absolute_path), None);
+    }
+
+    #[test]
+    fn relativize_non_stdlib_path_errors() {
+        let root = ModuleResolutionPathBuf::extra("foo/stdlib").unwrap();
+        // Must have a `.py` extension, a `.pyi` extension, or no extension:
+        let bad_absolute_path = FileSystemPath::new("foo/stdlib/x.rs");
+        assert_eq!(root.relativize_path(bad_absolute_path), None);
+        // Must be a path that is a child of `root`:
+        let second_bad_absolute_path = FileSystemPath::new("bar/stdlib/x.pyi");
+        assert_eq!(root.relativize_path(second_bad_absolute_path), None);
+    }
+
+    #[test]
+    fn relativize_path() {
+        assert_eq!(
+            ModuleResolutionPathBuf::standard_library("foo/baz")
+                .unwrap()
+                .relativize_path("foo/baz/eggs/__init__.pyi")
+                .unwrap(),
+            ModuleResolutionPathRef(ModuleResolutionPathRefInner::StandardLibrary(
+                FileSystemPath::new("eggs/__init__.pyi")
+            ))
+        );
+    }
+
+    fn py38_stdlib_test_case() -> (TestDb, ModuleResolutionPathBuf) {
+        let TestCase {
+            db,
+            custom_typeshed,
+            ..
+        } = create_resolver_builder().unwrap().build();
+        let stdlib_module_path =
+            ModuleResolutionPathBuf::stdlib_from_typeshed_root(&custom_typeshed).unwrap();
+        (db, stdlib_module_path)
+    }
+
+    #[test]
+    fn mocked_typeshed_existing_regular_stdlib_pkg_py38() {
+        let (db, stdlib_path) = py38_stdlib_test_case();
+        let resolver = ResolverState {
+            db: &db,
+            typeshed_versions: LazyTypeshedVersions::new(),
+            target_version: TargetVersion::Py38,
+        };
+
+        let asyncio_regular_package = stdlib_path.join("asyncio");
+        assert!(asyncio_regular_package.is_directory(&stdlib_path, &resolver));
+        assert!(asyncio_regular_package.is_regular_package(&stdlib_path, &resolver));
+        // Paths to directories don't resolve to VfsFiles
+        assert_eq!(
+            asyncio_regular_package.to_vfs_file(&stdlib_path, &resolver),
+            None
+        );
+        assert!(asyncio_regular_package
+            .join("__init__.pyi")
+            .to_vfs_file(&stdlib_path, &resolver)
+            .is_some());
+
+        // The `asyncio` package exists on Python 3.8, but the `asyncio.tasks` submodule does not,
+        // according to the `VERSIONS` file in our typeshed mock:
+        let asyncio_tasks_module = stdlib_path.join("asyncio/tasks.pyi");
+        assert_eq!(
+            asyncio_tasks_module.to_vfs_file(&stdlib_path, &resolver),
+            None
+        );
+        assert!(!asyncio_tasks_module.is_directory(&stdlib_path, &resolver));
+        assert!(!asyncio_tasks_module.is_regular_package(&stdlib_path, &resolver));
+    }
+
+    #[test]
+    fn mocked_typeshed_existing_namespace_stdlib_pkg_py38() {
+        let (db, stdlib_path) = py38_stdlib_test_case();
+        let resolver = ResolverState {
+            db: &db,
+            typeshed_versions: LazyTypeshedVersions::new(),
+            target_version: TargetVersion::Py38,
+        };
+
+        let xml_namespace_package = stdlib_path.join("xml");
+        assert!(xml_namespace_package.is_directory(&stdlib_path, &resolver));
+        // Paths to directories don't resolve to VfsFiles
+        assert_eq!(
+            xml_namespace_package.to_vfs_file(&stdlib_path, &resolver),
+            None
+        );
+        assert!(!xml_namespace_package.is_regular_package(&stdlib_path, &resolver));
+
+        let xml_etree = stdlib_path.join("xml/etree.pyi");
+        assert!(!xml_etree.is_directory(&stdlib_path, &resolver));
+        assert!(xml_etree.to_vfs_file(&stdlib_path, &resolver).is_some());
+        assert!(!xml_etree.is_regular_package(&stdlib_path, &resolver));
+    }
+
+    #[test]
+    fn mocked_typeshed_single_file_stdlib_module_py38() {
+        let (db, stdlib_path) = py38_stdlib_test_case();
+        let resolver = ResolverState {
+            db: &db,
+            typeshed_versions: LazyTypeshedVersions::new(),
+            target_version: TargetVersion::Py38,
+        };
+
+        let functools_module = stdlib_path.join("functools.pyi");
+        assert!(functools_module
+            .to_vfs_file(&stdlib_path, &resolver)
+            .is_some());
+        assert!(!functools_module.is_directory(&stdlib_path, &resolver));
+        assert!(!functools_module.is_regular_package(&stdlib_path, &resolver));
+    }
+
+    #[test]
+    fn mocked_typeshed_nonexistent_regular_stdlib_pkg_py38() {
+        let (db, stdlib_path) = py38_stdlib_test_case();
+        let resolver = ResolverState {
+            db: &db,
+            typeshed_versions: LazyTypeshedVersions::new(),
+            target_version: TargetVersion::Py38,
+        };
+
+        let collections_regular_package = stdlib_path.join("collections");
+        assert_eq!(
+            collections_regular_package.to_vfs_file(&stdlib_path, &resolver),
+            None
+        );
+        assert!(!collections_regular_package.is_directory(&stdlib_path, &resolver));
+        assert!(!collections_regular_package.is_regular_package(&stdlib_path, &resolver));
+    }
+
+    #[test]
+    fn mocked_typeshed_nonexistent_namespace_stdlib_pkg_py38() {
+        let (db, stdlib_path) = py38_stdlib_test_case();
+        let resolver = ResolverState {
+            db: &db,
+            typeshed_versions: LazyTypeshedVersions::new(),
+            target_version: TargetVersion::Py38,
+        };
+
+        let importlib_namespace_package = stdlib_path.join("importlib");
+        assert_eq!(
+            importlib_namespace_package.to_vfs_file(&stdlib_path, &resolver),
+            None
+        );
+        assert!(!importlib_namespace_package.is_directory(&stdlib_path, &resolver));
+        assert!(!importlib_namespace_package.is_regular_package(&stdlib_path, &resolver));
+
+        let importlib_abc = stdlib_path.join("importlib/abc.pyi");
+        assert_eq!(importlib_abc.to_vfs_file(&stdlib_path, &resolver), None);
+        assert!(!importlib_abc.is_directory(&stdlib_path, &resolver));
+        assert!(!importlib_abc.is_regular_package(&stdlib_path, &resolver));
+    }
+
+    #[test]
+    fn mocked_typeshed_nonexistent_single_file_module_py38() {
+        let (db, stdlib_path) = py38_stdlib_test_case();
+        let resolver = ResolverState {
+            db: &db,
+            typeshed_versions: LazyTypeshedVersions::new(),
+            target_version: TargetVersion::Py38,
+        };
+
+        let non_existent = stdlib_path.join("doesnt_even_exist");
+        assert_eq!(non_existent.to_vfs_file(&stdlib_path, &resolver), None);
+        assert!(!non_existent.is_directory(&stdlib_path, &resolver));
+        assert!(!non_existent.is_regular_package(&stdlib_path, &resolver));
+    }
+
+    fn py39_stdlib_test_case() -> (TestDb, ModuleResolutionPathBuf) {
+        let TestCase {
+            db,
+            custom_typeshed,
+            ..
+        } = create_resolver_builder()
+            .unwrap()
+            .with_target_version(TargetVersion::Py39)
+            .build();
+        let stdlib_module_path =
+            ModuleResolutionPathBuf::stdlib_from_typeshed_root(&custom_typeshed).unwrap();
+        (db, stdlib_module_path)
+    }
+
+    #[test]
+    fn mocked_typeshed_existing_regular_stdlib_pkgs_py39() {
+        let (db, stdlib_path) = py39_stdlib_test_case();
+        let resolver = ResolverState {
+            db: &db,
+            typeshed_versions: LazyTypeshedVersions::new(),
+            target_version: TargetVersion::Py39,
+        };
+
+        // Since we've set the target version to Py39,
+        // `collections` should now exist as a directory, according to VERSIONS...
+        let collections_regular_package = stdlib_path.join("collections");
+        assert!(collections_regular_package.is_directory(&stdlib_path, &resolver));
+        assert!(collections_regular_package.is_regular_package(&stdlib_path, &resolver));
+        // (This is still `None`, as directories don't resolve to `Vfs` files)
+        assert_eq!(
+            collections_regular_package.to_vfs_file(&stdlib_path, &resolver),
+            None
+        );
+        assert!(collections_regular_package
+            .join("__init__.pyi")
+            .to_vfs_file(&stdlib_path, &resolver)
+            .is_some());
+
+        // ...and so should the `asyncio.tasks` submodule (though it's still not a directory):
+        let asyncio_tasks_module = stdlib_path.join("asyncio/tasks.pyi");
+        assert!(asyncio_tasks_module
+            .to_vfs_file(&stdlib_path, &resolver)
+            .is_some());
+        assert!(!asyncio_tasks_module.is_directory(&stdlib_path, &resolver));
+        assert!(!asyncio_tasks_module.is_regular_package(&stdlib_path, &resolver));
+    }
+
+    #[test]
+    fn mocked_typeshed_existing_namespace_stdlib_pkg_py39() {
+        let (db, stdlib_path) = py39_stdlib_test_case();
+        let resolver = ResolverState {
+            db: &db,
+            typeshed_versions: LazyTypeshedVersions::new(),
+            target_version: TargetVersion::Py39,
+        };
+
+        // The `importlib` directory now also exists...
+        let importlib_namespace_package = stdlib_path.join("importlib");
+        assert!(importlib_namespace_package.is_directory(&stdlib_path, &resolver));
+        assert!(!importlib_namespace_package.is_regular_package(&stdlib_path, &resolver));
+        // (This is still `None`, as directories don't resolve to `Vfs` files)
+        assert_eq!(
+            importlib_namespace_package.to_vfs_file(&stdlib_path, &resolver),
+            None
+        );
+
+        // ...As do submodules in the `importlib` namespace package:
+        let importlib_abc = importlib_namespace_package.join("abc.pyi");
+        assert!(!importlib_abc.is_directory(&stdlib_path, &resolver));
+        assert!(!importlib_abc.is_regular_package(&stdlib_path, &resolver));
+        assert!(importlib_abc.to_vfs_file(&stdlib_path, &resolver).is_some());
+    }
+
+    #[test]
+    fn mocked_typeshed_nonexistent_namespace_stdlib_pkg_py39() {
+        let (db, stdlib_path) = py39_stdlib_test_case();
+        let resolver = ResolverState {
+            db: &db,
+            typeshed_versions: LazyTypeshedVersions::new(),
+            target_version: TargetVersion::Py39,
+        };
+
+        // The `xml` package no longer exists on py39:
+        let xml_namespace_package = stdlib_path.join("xml");
+        assert_eq!(
+            xml_namespace_package.to_vfs_file(&stdlib_path, &resolver),
+            None
+        );
+        assert!(!xml_namespace_package.is_directory(&stdlib_path, &resolver));
+        assert!(!xml_namespace_package.is_regular_package(&stdlib_path, &resolver));
+
+        let xml_etree = xml_namespace_package.join("etree.pyi");
+        assert_eq!(xml_etree.to_vfs_file(&stdlib_path, &resolver), None);
+        assert!(!xml_etree.is_directory(&stdlib_path, &resolver));
+        assert!(!xml_etree.is_regular_package(&stdlib_path, &resolver));
+    }
+}

crates/red_knot_module_resolver/src/resolver.rs

@@ -0,0 +1,985 @@
+use std::ops::Deref;
+use std::sync::Arc;
+
+use ruff_db::file_system::FileSystemPathBuf;
+use ruff_db::vfs::{vfs_path_to_file, VfsFile, VfsPath};
+
+use crate::db::Db;
+use crate::module::{Module, ModuleKind};
+use crate::module_name::ModuleName;
+use crate::path::ModuleResolutionPathBuf;
+use crate::resolver::internal::ModuleResolverSettings;
+use crate::state::ResolverState;
+use crate::supported_py_version::TargetVersion;
+
+/// Configures the module resolver settings.
+///
+/// Must be called before calling any other module resolution functions.
+pub fn set_module_resolution_settings(db: &mut dyn Db, config: RawModuleResolutionSettings) {
+    // There's no concurrency issue here because we hold a `&mut dyn Db` reference. No other
+    // thread can mutate the `Db` while we're in this call, so using `try_get` to test if
+    // the settings have already been set is safe.
+    let resolved_settings = config.into_configuration_settings();
+    if let Some(existing) = ModuleResolverSettings::try_get(db) {
+        existing.set_settings(db).to(resolved_settings);
+    } else {
+        ModuleResolverSettings::new(db, resolved_settings);
+    }
+}
+
+/// Resolves a module name to a module.
+pub fn resolve_module(db: &dyn Db, module_name: ModuleName) -> Option<Module> {
+    let interned_name = internal::ModuleNameIngredient::new(db, module_name);
+
+    resolve_module_query(db, interned_name)
+}
+
+/// Salsa query that resolves an interned [`ModuleNameIngredient`] to a module.
+///
+/// This query should not be called directly. Instead, use [`resolve_module`]. It only exists
+/// because Salsa requires the module name to be an ingredient.
+#[salsa::tracked]
+pub(crate) fn resolve_module_query<'db>(
+    db: &'db dyn Db,
+    module_name: internal::ModuleNameIngredient<'db>,
+) -> Option<Module> {
+    let _span = tracing::trace_span!("resolve_module", ?module_name).entered();
+
+    let name = module_name.name(db);
+
+    let (search_path, module_file, kind) = resolve_name(db, name)?;
+
+    let module = Module::new(name.clone(), kind, search_path, module_file);
+
+    Some(module)
+}
+
+/// Resolves the module for the given path.
+///
+/// Returns `None` if the path is not a module locatable via any of the known search paths.
+#[allow(unused)]
+pub(crate) fn path_to_module(db: &dyn Db, path: &VfsPath) -> Option<Module> {
+    // It's not entirely clear on first sight why this method calls `file_to_module` instead of
+    // it being the other way round, considering that the first thing that `file_to_module` does
+    // is to retrieve the file's path.
+    //
+    // The reason is that `file_to_module` is a tracked Salsa query and salsa queries require that
+    // all arguments are Salsa ingredients (something stored in Salsa). `Path`s aren't salsa ingredients but
+    // `VfsFile` is. So what we do here is to retrieve the `path`'s `VfsFile` so that we can make
+    // use of Salsa's caching and invalidation.
+    let file = vfs_path_to_file(db.upcast(), path)?;
+    file_to_module(db, file)
+}
+
+/// Resolves the module for the file with the given id.
+///
+/// Returns `None` if the file is not a module locatable via any of the known search paths.
+#[salsa::tracked]
+pub(crate) fn file_to_module(db: &dyn Db, file: VfsFile) -> Option<Module> {
+    let _span = tracing::trace_span!("file_to_module", ?file).entered();
+
+    let VfsPath::FileSystem(path) = file.path(db.upcast()) else {
+        todo!("VendoredPaths are not yet supported")
+    };
+
+    let resolver_settings = module_resolver_settings(db);
+
+    let relative_path = resolver_settings
+        .search_paths()
+        .iter()
+        .find_map(|root| root.relativize_path(path))?;
+
+    let module_name = relative_path.to_module_name()?;
+
+    // Resolve the module name to see if Python would resolve the name to the same path.
+    // If it doesn't, then that means that multiple modules have the same name in different
+    // root paths, but that the module corresponding to `path` is in a lower priority search path,
+    // in which case we ignore it.
+    let module = resolve_module(db, module_name)?;
+
+    if file == module.file() {
+        Some(module)
+    } else {
+        // This path is for a module with the same name but with a different precedence. For example:
+        // ```
+        // src/foo.py
+        // src/foo/__init__.py
+        // ```
+        // The module name of `src/foo.py` is `foo`, but the module loaded by Python is `src/foo/__init__.py`.
+        // That means we need to ignore `src/foo.py` even though it resolves to the same module name.
+        None
+    }
+}
+
+/// "Raw" configuration settings for module resolution: unvalidated, unnormalized
+#[derive(Eq, PartialEq, Debug)]
+pub struct RawModuleResolutionSettings {
+    /// The target Python version the user has specified
+    pub target_version: TargetVersion,
+
+    /// List of user-provided paths that should take first priority in the module resolution.
+    /// Examples in other type checkers are mypy's MYPYPATH environment variable,
+    /// or pyright's stubPath configuration setting.
+    pub extra_paths: Vec<FileSystemPathBuf>,
+
+    /// The root of the workspace, used for finding first-party modules.
+    pub workspace_root: FileSystemPathBuf,
+
+    /// Optional (already validated) path to standard-library typeshed stubs.
+    /// If this is not provided, we will fallback to our vendored typeshed stubs
+    /// bundled as a zip file in the binary
+    pub custom_typeshed: Option<FileSystemPathBuf>,
+
+    /// The path to the user's `site-packages` directory, where third-party packages from ``PyPI`` are installed.
+    pub site_packages: Option<FileSystemPathBuf>,
+}
+
+impl RawModuleResolutionSettings {
+    /// Implementation of the typing spec's [module resolution order]
+    ///
+    /// TODO(Alex): this method does multiple `.unwrap()` calls when it should really return an error.
+    /// Each `.unwrap()` call is a point where we're validating a setting that the user would pass
+    /// and transforming it into an internal representation for a validated path.
+    /// Rather than panicking if a path fails to validate, we should display an error message to the user
+    /// and exit the process with a nonzero exit code.
+    /// This validation should probably be done outside of Salsa?
+    ///
+    /// [module resolution order]: https://typing.readthedocs.io/en/latest/spec/distributing.html#import-resolution-ordering
+    fn into_configuration_settings(self) -> ModuleResolutionSettings {
+        let RawModuleResolutionSettings {
+            target_version,
+            extra_paths,
+            workspace_root,
+            site_packages,
+            custom_typeshed,
+        } = self;
+
+        let mut paths: Vec<ModuleResolutionPathBuf> = extra_paths
+            .into_iter()
+            .map(|fs_path| ModuleResolutionPathBuf::extra(fs_path).unwrap())
+            .collect();
+
+        paths.push(ModuleResolutionPathBuf::first_party(workspace_root).unwrap());
+
+        if let Some(custom_typeshed) = custom_typeshed {
+            paths.push(
+                ModuleResolutionPathBuf::stdlib_from_typeshed_root(&custom_typeshed).unwrap(),
+            );
+        }
+
+        // TODO vendor typeshed's third-party stubs as well as the stdlib and fallback to them as a final step
+        if let Some(site_packages) = site_packages {
+            paths.push(ModuleResolutionPathBuf::site_packages(site_packages).unwrap());
+        }
+
+        ModuleResolutionSettings {
+            target_version,
+            search_paths: OrderedSearchPaths(paths.into_iter().map(Arc::new).collect()),
+        }
+    }
+}
+
+/// A resolved module resolution order as per the [typing spec]
+///
+/// [typing spec]: https://typing.readthedocs.io/en/latest/spec/distributing.html#import-resolution-ordering
+#[derive(Clone, Debug, Default, Eq, PartialEq)]
+pub(crate) struct OrderedSearchPaths(Vec<Arc<ModuleResolutionPathBuf>>);
+
+impl Deref for OrderedSearchPaths {
+    type Target = [Arc<ModuleResolutionPathBuf>];
+
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
+
+#[derive(Clone, Debug, PartialEq, Eq)]
+pub(crate) struct ModuleResolutionSettings {
+    search_paths: OrderedSearchPaths,
+    target_version: TargetVersion,
+}
+
+impl ModuleResolutionSettings {
+    pub(crate) fn search_paths(&self) -> &[Arc<ModuleResolutionPathBuf>] {
+        &self.search_paths
+    }
+
+    pub(crate) fn target_version(&self) -> TargetVersion {
+        self.target_version
+    }
+}
+
+// The singleton methods generated by salsa are all `pub` instead of `pub(crate)` which triggers
+// `unreachable_pub`. Work around this by creating a module and allow `unreachable_pub` for it.
+// Salsa also generates uses to `_db` variables for `interned` which triggers `clippy::used_underscore_binding`. Suppress that too
+// TODO(micha): Contribute a fix for this upstream where the singleton methods have the same visibility as the struct.
+#[allow(unreachable_pub, clippy::used_underscore_binding)]
+pub(crate) mod internal {
+    use crate::module_name::ModuleName;
+    use crate::resolver::ModuleResolutionSettings;
+
+    #[salsa::input(singleton)]
+    pub(crate) struct ModuleResolverSettings {
+        #[return_ref]
+        pub(super) settings: ModuleResolutionSettings,
+    }
+
+    /// A thin wrapper around `ModuleName` to make it a Salsa ingredient.
+    ///
+    /// This is needed because Salsa requires that all query arguments are salsa ingredients.
+    #[salsa::interned]
+    pub(crate) struct ModuleNameIngredient<'db> {
+        #[return_ref]
+        pub(super) name: ModuleName,
+    }
+}
+
+fn module_resolver_settings(db: &dyn Db) -> &ModuleResolutionSettings {
+    ModuleResolverSettings::get(db).settings(db)
+}
+
+/// Given a module name and a list of search paths in which to lookup modules,
+/// attempt to resolve the module name
+fn resolve_name(
+    db: &dyn Db,
+    name: &ModuleName,
+) -> Option<(Arc<ModuleResolutionPathBuf>, VfsFile, ModuleKind)> {
+    let resolver_settings = module_resolver_settings(db);
+    let resolver_state = ResolverState::new(db, resolver_settings.target_version());
+
+    for search_path in resolver_settings.search_paths() {
+        let mut components = name.components();
+        let module_name = components.next_back()?;
+
+        match resolve_package(search_path, components, &resolver_state) {
+            Ok(resolved_package) => {
+                let mut package_path = resolved_package.path;
+
+                package_path.push(module_name);
+
+                // Must be a `__init__.pyi` or `__init__.py` or it isn't a package.
+                let kind = if package_path.is_directory(search_path, &resolver_state) {
+                    package_path.push("__init__");
+                    ModuleKind::Package
+                } else {
+                    ModuleKind::Module
+                };
+
+                // TODO Implement full https://peps.python.org/pep-0561/#type-checker-module-resolution-order resolution
+                if let Some(stub) = package_path
+                    .with_pyi_extension()
+                    .to_vfs_file(search_path, &resolver_state)
+                {
+                    return Some((search_path.clone(), stub, kind));
+                }
+
+                if let Some(module) = package_path
+                    .with_py_extension()
+                    .and_then(|path| path.to_vfs_file(search_path, &resolver_state))
+                {
+                    return Some((search_path.clone(), module, kind));
+                }
+
+                // For regular packages, don't search the next search path. All files of that
+                // package must be in the same location
+                if resolved_package.kind.is_regular_package() {
+                    return None;
+                }
+            }
+            Err(parent_kind) => {
+                if parent_kind.is_regular_package() {
+                    // For regular packages, don't search the next search path.
+                    return None;
+                }
+            }
+        }
+    }
+
+    None
+}
+
+fn resolve_package<'a, 'db, I>(
+    module_search_path: &ModuleResolutionPathBuf,
+    components: I,
+    resolver_state: &ResolverState<'db>,
+) -> Result<ResolvedPackage, PackageKind>
+where
+    I: Iterator<Item = &'a str>,
+{
+    let mut package_path = module_search_path.clone();
+
+    // `true` if inside a folder that is a namespace package (has no `__init__.py`).
+    // Namespace packages are special because they can be spread across multiple search paths.
+    // https://peps.python.org/pep-0420/
+    let mut in_namespace_package = false;
+
+    // `true` if resolving a sub-package. For example, `true` when resolving `bar` of `foo.bar`.
+    let mut in_sub_package = false;
+
+    // For `foo.bar.baz`, test that `foo` and `baz` both contain a `__init__.py`.
+    for folder in components {
+        package_path.push(folder);
+
+        let is_regular_package =
+            package_path.is_regular_package(module_search_path, resolver_state);
+
+        if is_regular_package {
+            in_namespace_package = false;
+        } else if package_path.is_directory(module_search_path, resolver_state) {
+            // A directory without an `__init__.py` is a namespace package, continue with the next folder.
+            in_namespace_package = true;
+        } else if in_namespace_package {
+            // Package not found but it is part of a namespace package.
+            return Err(PackageKind::Namespace);
+        } else if in_sub_package {
+            // A regular sub package wasn't found.
+            return Err(PackageKind::Regular);
+        } else {
+            // We couldn't find `foo` for `foo.bar.baz`, search the next search path.
+            return Err(PackageKind::Root);
+        }
+
+        in_sub_package = true;
+    }
+
+    let kind = if in_namespace_package {
+        PackageKind::Namespace
+    } else if in_sub_package {
+        PackageKind::Regular
+    } else {
+        PackageKind::Root
+    };
+
+    Ok(ResolvedPackage {
+        kind,
+        path: package_path,
+    })
+}
+
+#[derive(Debug)]
+struct ResolvedPackage {
+    path: ModuleResolutionPathBuf,
+    kind: PackageKind,
+}
+
+#[derive(Copy, Clone, Eq, PartialEq, Debug)]
+enum PackageKind {
+    /// A root package or module. E.g. `foo` in `foo.bar.baz` or just `foo`.
+    Root,
+
+    /// A regular sub-package where the parent contains an `__init__.py`.
+    ///
+    /// For example, `bar` in `foo.bar` when the `foo` directory contains an `__init__.py`.
+    Regular,
+
+    /// A sub-package in a namespace package. A namespace package is a package without an `__init__.py`.
+    ///
+    /// For example, `bar` in `foo.bar` if the `foo` directory contains no `__init__.py`.
+    Namespace,
+}
+
+impl PackageKind {
+    const fn is_regular_package(self) -> bool {
+        matches!(self, PackageKind::Regular)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use ruff_db::file_system::FileSystemPath;
+    use ruff_db::vfs::{system_path_to_file, VfsFile, VfsPath};
+
+    use crate::db::tests::{create_resolver_builder, TestCase};
+    use crate::module::ModuleKind;
+    use crate::module_name::ModuleName;
+
+    use super::*;
+
+    fn setup_resolver_test() -> TestCase {
+        create_resolver_builder().unwrap().build()
+    }
+
+    #[test]
+    fn first_party_module() -> anyhow::Result<()> {
+        let TestCase { db, src, .. } = setup_resolver_test();
+
+        let foo_module_name = ModuleName::new_static("foo").unwrap();
+        let foo_path = src.join("foo.py");
+        db.memory_file_system()
+            .write_file(&foo_path, "print('Hello, world!')")?;
+
+        let foo_module = resolve_module(&db, foo_module_name.clone()).unwrap();
+
+        assert_eq!(
+            Some(&foo_module),
+            resolve_module(&db, foo_module_name.clone()).as_ref()
+        );
+
+        assert_eq!("foo", foo_module.name());
+        assert_eq!(&src, &foo_module.search_path());
+        assert_eq!(ModuleKind::Module, foo_module.kind());
+
+        assert_eq!(&foo_path, foo_module.file().path(&db));
+        assert_eq!(
+            Some(foo_module),
+            path_to_module(&db, &VfsPath::FileSystem(foo_path))
+        );
+
+        Ok(())
+    }
+
+    #[test]
+    fn stdlib() {
+        let TestCase {
+            db,
+            custom_typeshed,
+            ..
+        } = setup_resolver_test();
+
+        let stdlib_dir =
+            ModuleResolutionPathBuf::stdlib_from_typeshed_root(&custom_typeshed).unwrap();
+        let functools_module_name = ModuleName::new_static("functools").unwrap();
+        let functools_module = resolve_module(&db, functools_module_name.clone()).unwrap();
+
+        assert_eq!(
+            Some(&functools_module),
+            resolve_module(&db, functools_module_name).as_ref()
+        );
+
+        assert_eq!(stdlib_dir, functools_module.search_path().to_path_buf());
+        assert_eq!(ModuleKind::Module, functools_module.kind());
+
+        let expected_functools_path =
+            VfsPath::FileSystem(custom_typeshed.join("stdlib/functools.pyi"));
+        assert_eq!(&expected_functools_path, functools_module.file().path(&db));
+
+        assert_eq!(
+            Some(functools_module),
+            path_to_module(&db, &expected_functools_path)
+        );
+    }
+
+    fn create_module_names(raw_names: &[&str]) -> Vec<ModuleName> {
+        raw_names
+            .iter()
+            .map(|raw| ModuleName::new(raw).unwrap())
+            .collect()
+    }
+
+    #[test]
+    fn stdlib_resolution_respects_versions_file_py38_existing_modules() {
+        let TestCase {
+            db,
+            custom_typeshed,
+            ..
+        } = setup_resolver_test();
+
+        let existing_modules = create_module_names(&["asyncio", "functools", "xml.etree"]);
+        for module_name in existing_modules {
+            let resolved_module = resolve_module(&db, module_name.clone()).unwrap_or_else(|| {
+                panic!("Expected module {module_name} to exist in the mock stdlib")
+            });
+            let search_path = resolved_module.search_path();
+            assert_eq!(
+                &custom_typeshed.join("stdlib"),
+                &search_path,
+                "Search path for {module_name} was unexpectedly {search_path:?}"
+            );
+            assert!(
+                search_path.is_stdlib_search_path(),
+                "Expected a stdlib search path, but got {search_path:?}"
+            );
+        }
+    }
+
+    #[test]
+    fn stdlib_resolution_respects_versions_file_py38_nonexisting_modules() {
+        let TestCase { db, .. } = setup_resolver_test();
+        let nonexisting_modules = create_module_names(&[
+            "collections",
+            "importlib",
+            "importlib.abc",
+            "xml",
+            "asyncio.tasks",
+        ]);
+        for module_name in nonexisting_modules {
+            assert!(
+                resolve_module(&db, module_name.clone()).is_none(),
+                "Unexpectedly resolved a module for {module_name}"
+            );
+        }
+    }
+
+    #[test]
+    fn stdlib_resolution_respects_versions_file_py39_existing_modules() {
+        let TestCase {
+            db,
+            custom_typeshed,
+            ..
+        } = create_resolver_builder()
+            .unwrap()
+            .with_target_version(TargetVersion::Py39)
+            .build();
+
+        let existing_modules = create_module_names(&[
+            "asyncio",
+            "functools",
+            "importlib.abc",
+            "collections",
+            "asyncio.tasks",
+        ]);
+        for module_name in existing_modules {
+            let resolved_module = resolve_module(&db, module_name.clone()).unwrap_or_else(|| {
+                panic!("Expected module {module_name} to exist in the mock stdlib")
+            });
+            let search_path = resolved_module.search_path();
+            assert_eq!(
+                &custom_typeshed.join("stdlib"),
+                &search_path,
+                "Search path for {module_name} was unexpectedly {search_path:?}"
+            );
+            assert!(
+                search_path.is_stdlib_search_path(),
+                "Expected a stdlib search path, but got {search_path:?}"
+            );
+        }
+    }
+    #[test]
+    fn stdlib_resolution_respects_versions_file_py39_nonexisting_modules() {
+        let TestCase { db, .. } = create_resolver_builder()
+            .unwrap()
+            .with_target_version(TargetVersion::Py39)
+            .build();
+
+        let nonexisting_modules = create_module_names(&["importlib", "xml", "xml.etree"]);
+        for module_name in nonexisting_modules {
+            assert!(
+                resolve_module(&db, module_name.clone()).is_none(),
+                "Unexpectedly resolved a module for {module_name}"
+            );
+        }
+    }
+
+    #[test]
+    fn first_party_precedence_over_stdlib() -> anyhow::Result<()> {
+        let TestCase { db, src, .. } = setup_resolver_test();
+
+        let first_party_functools_path = src.join("functools.py");
+        db.memory_file_system()
+            .write_file(&first_party_functools_path, "def update_wrapper(): ...")?;
+
+        let functools_module_name = ModuleName::new_static("functools").unwrap();
+        let functools_module = resolve_module(&db, functools_module_name.clone()).unwrap();
+
+        assert_eq!(
+            Some(&functools_module),
+            resolve_module(&db, functools_module_name).as_ref()
+        );
+        assert_eq!(&src, &functools_module.search_path());
+        assert_eq!(ModuleKind::Module, functools_module.kind());
+        assert_eq!(
+            &first_party_functools_path,
+            functools_module.file().path(&db)
+        );
+
+        assert_eq!(
+            Some(functools_module),
+            path_to_module(&db, &VfsPath::FileSystem(first_party_functools_path))
+        );
+
+        Ok(())
+    }
+
+    #[test]
+    fn resolve_package() -> anyhow::Result<()> {
+        let TestCase { src, db, .. } = setup_resolver_test();
+
+        let foo_dir = src.join("foo");
+        let foo_path = foo_dir.join("__init__.py");
+
+        db.memory_file_system()
+            .write_file(&foo_path, "print('Hello, world!')")?;
+
+        let foo_module = resolve_module(&db, ModuleName::new_static("foo").unwrap()).unwrap();
+
+        assert_eq!("foo", foo_module.name());
+        assert_eq!(&src, &foo_module.search_path());
+        assert_eq!(&foo_path, foo_module.file().path(&db));
+
+        assert_eq!(
+            Some(&foo_module),
+            path_to_module(&db, &VfsPath::FileSystem(foo_path)).as_ref()
+        );
+
+        // Resolving by directory doesn't resolve to the init file.
+        assert_eq!(None, path_to_module(&db, &VfsPath::FileSystem(foo_dir)));
+
+        Ok(())
+    }
+
+    #[test]
+    fn package_priority_over_module() -> anyhow::Result<()> {
+        let TestCase { db, src, .. } = setup_resolver_test();
+
+        let foo_dir = src.join("foo");
+        let foo_init = foo_dir.join("__init__.py");
+
+        db.memory_file_system()
+            .write_file(&foo_init, "print('Hello, world!')")?;
+
+        let foo_py = src.join("foo.py");
+        db.memory_file_system()
+            .write_file(&foo_py, "print('Hello, world!')")?;
+
+        let foo_module = resolve_module(&db, ModuleName::new_static("foo").unwrap()).unwrap();
+
+        assert_eq!(&src, &foo_module.search_path());
+        assert_eq!(&foo_init, foo_module.file().path(&db));
+        assert_eq!(ModuleKind::Package, foo_module.kind());
+
+        assert_eq!(
+            Some(foo_module),
+            path_to_module(&db, &VfsPath::FileSystem(foo_init))
+        );
+        assert_eq!(None, path_to_module(&db, &VfsPath::FileSystem(foo_py)));
+
+        Ok(())
+    }
+
+    #[test]
+    fn typing_stub_over_module() -> anyhow::Result<()> {
+        let TestCase { db, src, .. } = setup_resolver_test();
+
+        let foo_stub = src.join("foo.pyi");
+        let foo_py = src.join("foo.py");
+        db.memory_file_system()
+            .write_files([(&foo_stub, "x: int"), (&foo_py, "print('Hello, world!')")])?;
+
+        let foo = resolve_module(&db, ModuleName::new_static("foo").unwrap()).unwrap();
+
+        assert_eq!(&src, &foo.search_path());
+        assert_eq!(&foo_stub, foo.file().path(&db));
+
+        assert_eq!(
+            Some(foo),
+            path_to_module(&db, &VfsPath::FileSystem(foo_stub))
+        );
+        assert_eq!(None, path_to_module(&db, &VfsPath::FileSystem(foo_py)));
+
+        Ok(())
+    }
+
+    #[test]
+    fn sub_packages() -> anyhow::Result<()> {
+        let TestCase { db, src, .. } = setup_resolver_test();
+
+        let foo = src.join("foo");
+        let bar = foo.join("bar");
+        let baz = bar.join("baz.py");
+
+        db.memory_file_system().write_files([
+            (&foo.join("__init__.py"), ""),
+            (&bar.join("__init__.py"), ""),
+            (&baz, "print('Hello, world!')"),
+        ])?;
+
+        let baz_module =
+            resolve_module(&db, ModuleName::new_static("foo.bar.baz").unwrap()).unwrap();
+
+        assert_eq!(&src, &baz_module.search_path());
+        assert_eq!(&baz, baz_module.file().path(&db));
+
+        assert_eq!(
+            Some(baz_module),
+            path_to_module(&db, &VfsPath::FileSystem(baz))
+        );
+
+        Ok(())
+    }
+
+    #[test]
+    fn namespace_package() -> anyhow::Result<()> {
+        let TestCase {
+            db,
+            src,
+            site_packages,
+            ..
+        } = setup_resolver_test();
+
+        // From [PEP420](https://peps.python.org/pep-0420/#nested-namespace-packages).
+        // But uses `src` for `project1` and `site_packages2` for `project2`.
+        // ```
+        // src
+        //   parent
+        //     child
+        //       one.py
+        // site_packages
+        //   parent
+        //     child
+        //       two.py
+        // ```
+
+        let parent1 = src.join("parent");
+        let child1 = parent1.join("child");
+        let one = child1.join("one.py");
+
+        let parent2 = site_packages.join("parent");
+        let child2 = parent2.join("child");
+        let two = child2.join("two.py");
+
+        db.memory_file_system().write_files([
+            (&one, "print('Hello, world!')"),
+            (&two, "print('Hello, world!')"),
+        ])?;
+
+        let one_module =
+            resolve_module(&db, ModuleName::new_static("parent.child.one").unwrap()).unwrap();
+
+        assert_eq!(
+            Some(one_module),
+            path_to_module(&db, &VfsPath::FileSystem(one))
+        );
+
+        let two_module =
+            resolve_module(&db, ModuleName::new_static("parent.child.two").unwrap()).unwrap();
+        assert_eq!(
+            Some(two_module),
+            path_to_module(&db, &VfsPath::FileSystem(two))
+        );
+
+        Ok(())
+    }
+
+    #[test]
+    fn regular_package_in_namespace_package() -> anyhow::Result<()> {
+        let TestCase {
+            db,
+            src,
+            site_packages,
+            ..
+        } = setup_resolver_test();
+
+        // Adopted test case from the [PEP420 examples](https://peps.python.org/pep-0420/#nested-namespace-packages).
+        // The `src/parent/child` package is a regular package. Therefore, `site_packages/parent/child/two.py` should not be resolved.
+        // ```
+        // src
+        //   parent
+        //     child
+        //       one.py
+        // site_packages
+        //   parent
+        //     child
+        //       two.py
+        // ```
+
+        let parent1 = src.join("parent");
+        let child1 = parent1.join("child");
+        let one = child1.join("one.py");
+
+        let parent2 = site_packages.join("parent");
+        let child2 = parent2.join("child");
+        let two = child2.join("two.py");
+
+        db.memory_file_system().write_files([
+            (&child1.join("__init__.py"), "print('Hello, world!')"),
+            (&one, "print('Hello, world!')"),
+            (&two, "print('Hello, world!')"),
+        ])?;
+
+        let one_module =
+            resolve_module(&db, ModuleName::new_static("parent.child.one").unwrap()).unwrap();
+
+        assert_eq!(
+            Some(one_module),
+            path_to_module(&db, &VfsPath::FileSystem(one))
+        );
+
+        assert_eq!(
+            None,
+            resolve_module(&db, ModuleName::new_static("parent.child.two").unwrap())
+        );
+        Ok(())
+    }
+
+    #[test]
+    fn module_search_path_priority() -> anyhow::Result<()> {
+        let TestCase {
+            db,
+            src,
+            site_packages,
+            ..
+        } = setup_resolver_test();
+
+        let foo_src = src.join("foo.py");
+        let foo_site_packages = site_packages.join("foo.py");
+
+        db.memory_file_system()
+            .write_files([(&foo_src, ""), (&foo_site_packages, "")])?;
+
+        let foo_module = resolve_module(&db, ModuleName::new_static("foo").unwrap()).unwrap();
+
+        assert_eq!(&src, &foo_module.search_path());
+        assert_eq!(&foo_src, foo_module.file().path(&db));
+
+        assert_eq!(
+            Some(foo_module),
+            path_to_module(&db, &VfsPath::FileSystem(foo_src))
+        );
+        assert_eq!(
+            None,
+            path_to_module(&db, &VfsPath::FileSystem(foo_site_packages))
+        );
+
+        Ok(())
+    }
+
+    #[test]
+    #[cfg(target_family = "unix")]
+    fn symlink() -> anyhow::Result<()> {
+        let TestCase {
+            mut db,
+            src,
+            site_packages,
+            custom_typeshed,
+        } = setup_resolver_test();
+
+        db.with_os_file_system();
+
+        let temp_dir = tempfile::tempdir()?;
+        let root = FileSystemPath::from_std_path(temp_dir.path()).unwrap();
+
+        let src = root.join(src);
+        let site_packages = root.join(site_packages);
+        let custom_typeshed = root.join(custom_typeshed);
+
+        let foo = src.join("foo.py");
+        let bar = src.join("bar.py");
+
+        std::fs::create_dir_all(src.as_std_path())?;
+        std::fs::create_dir_all(site_packages.as_std_path())?;
+        std::fs::create_dir_all(custom_typeshed.as_std_path())?;
+
+        std::fs::write(foo.as_std_path(), "")?;
+        std::os::unix::fs::symlink(foo.as_std_path(), bar.as_std_path())?;
+
+        let settings = RawModuleResolutionSettings {
+            target_version: TargetVersion::Py38,
+            extra_paths: vec![],
+            workspace_root: src.clone(),
+            site_packages: Some(site_packages.clone()),
+            custom_typeshed: Some(custom_typeshed.clone()),
+        };
+
+        set_module_resolution_settings(&mut db, settings);
+
+        let foo_module = resolve_module(&db, ModuleName::new_static("foo").unwrap()).unwrap();
+        let bar_module = resolve_module(&db, ModuleName::new_static("bar").unwrap()).unwrap();
+
+        assert_ne!(foo_module, bar_module);
+
+        assert_eq!(&src, &foo_module.search_path());
+        assert_eq!(&foo, foo_module.file().path(&db));
+
+        // `foo` and `bar` shouldn't resolve to the same file
+
+        assert_eq!(&src, &bar_module.search_path());
+        assert_eq!(&bar, bar_module.file().path(&db));
+        assert_eq!(&foo, foo_module.file().path(&db));
+
+        assert_ne!(&foo_module, &bar_module);
+
+        assert_eq!(
+            Some(foo_module),
+            path_to_module(&db, &VfsPath::FileSystem(foo))
+        );
+        assert_eq!(
+            Some(bar_module),
+            path_to_module(&db, &VfsPath::FileSystem(bar))
+        );
+
+        Ok(())
+    }
+
+    #[test]
+    fn deleting_an_unrelated_file_doesnt_change_module_resolution() -> anyhow::Result<()> {
+        let TestCase { mut db, src, .. } = setup_resolver_test();
+
+        let foo_path = src.join("foo.py");
+        let bar_path = src.join("bar.py");
+
+        db.memory_file_system()
+            .write_files([(&foo_path, "x = 1"), (&bar_path, "y = 2")])?;
+
+        let foo_module_name = ModuleName::new_static("foo").unwrap();
+        let foo_module = resolve_module(&db, foo_module_name.clone()).unwrap();
+
+        let bar = system_path_to_file(&db, &bar_path).expect("bar.py to exist");
+
+        db.clear_salsa_events();
+
+        // Delete `bar.py`
+        db.memory_file_system().remove_file(&bar_path)?;
+        bar.touch(&mut db);
+
+        // Re-query the foo module. The foo module should still be cached because `bar.py` isn't relevant
+        // for resolving `foo`.
+
+        let foo_module2 = resolve_module(&db, foo_module_name);
+
+        assert!(!db
+            .take_salsa_events()
+            .iter()
+            .any(|event| { matches!(event.kind, salsa::EventKind::WillExecute { .. }) }));
+
+        assert_eq!(Some(foo_module), foo_module2);
+
+        Ok(())
+    }
+
+    #[test]
+    fn adding_a_file_on_which_the_module_resolution_depends_on_invalidates_the_query(
+    ) -> anyhow::Result<()> {
+        let TestCase { mut db, src, .. } = setup_resolver_test();
+        let foo_path = src.join("foo.py");
+
+        let foo_module_name = ModuleName::new_static("foo").unwrap();
+        assert_eq!(resolve_module(&db, foo_module_name.clone()), None);
+
+        // Now write the foo file
+        db.memory_file_system().write_file(&foo_path, "x = 1")?;
+        VfsFile::touch_path(&mut db, &VfsPath::FileSystem(foo_path.clone()));
+        let foo_file = system_path_to_file(&db, &foo_path).expect("foo.py to exist");
+
+        let foo_module = resolve_module(&db, foo_module_name).expect("Foo module to resolve");
+        assert_eq!(foo_file, foo_module.file());
+
+        Ok(())
+    }
+
+    #[test]
+    fn removing_a_file_that_the_module_resolution_depends_on_invalidates_the_query(
+    ) -> anyhow::Result<()> {
+        let TestCase { mut db, src, .. } = setup_resolver_test();
+        let foo_path = src.join("foo.py");
+        let foo_init_path = src.join("foo/__init__.py");
+
+        db.memory_file_system()
+            .write_files([(&foo_path, "x = 1"), (&foo_init_path, "x = 2")])?;
+
+        let foo_module_name = ModuleName::new_static("foo").unwrap();
+        let foo_module = resolve_module(&db, foo_module_name.clone()).expect("foo module to exist");
+
+        assert_eq!(&foo_init_path, foo_module.file().path(&db));
+
+        // Delete `foo/__init__.py` and the `foo` folder. `foo` should now resolve to `foo.py`
+        db.memory_file_system().remove_file(&foo_init_path)?;
+        db.memory_file_system()
+            .remove_directory(foo_init_path.parent().unwrap())?;
+        VfsFile::touch_path(&mut db, &VfsPath::FileSystem(foo_init_path));
+
+        let foo_module = resolve_module(&db, foo_module_name).expect("Foo module to resolve");
+        assert_eq!(&foo_path, foo_module.file().path(&db));
+
+        Ok(())
+    }
+}

crates/red_knot_module_resolver/src/state.rs

@@ -0,0 +1,25 @@
+use ruff_db::file_system::FileSystem;
+
+use crate::db::Db;
+use crate::supported_py_version::TargetVersion;
+use crate::typeshed::LazyTypeshedVersions;
+
+pub(crate) struct ResolverState<'db> {
+    pub(crate) db: &'db dyn Db,
+    pub(crate) typeshed_versions: LazyTypeshedVersions<'db>,
+    pub(crate) target_version: TargetVersion,
+}
+
+impl<'db> ResolverState<'db> {
+    pub(crate) fn new(db: &'db dyn Db, target_version: TargetVersion) -> Self {
+        Self {
+            db,
+            typeshed_versions: LazyTypeshedVersions::new(),
+            target_version,
+        }
+    }
+
+    pub(crate) fn file_system(&self) -> &dyn FileSystem {
+        self.db.file_system()
+    }
+}

crates/red_knot_module_resolver/src/supported_py_version.rs

@@ -0,0 +1,14 @@
+/// Enumeration of all supported Python versions
+///
+/// TODO: unify with the `PythonVersion` enum in the linter/formatter crates?
+#[derive(Copy, Clone, Hash, Debug, PartialEq, Eq, PartialOrd, Ord, Default)]
+pub enum TargetVersion {
+    Py37,
+    #[default]
+    Py38,
+    Py39,
+    Py310,
+    Py311,
+    Py312,
+    Py313,
+}

crates/red_knot_module_resolver/src/typeshed.rs

@@ -1,24 +1,22 @@
-use ruff_db::vendored::VendoredFileSystem;
-use std::sync::LazyLock;
+mod versions;
 
-// The file path here is hardcoded in this crate's `build.rs` script.
-// Luckily this crate will fail to build if this file isn't available at build time.
-static TYPESHED_ZIP_BYTES: &[u8] = include_bytes!(concat!(env!("OUT_DIR"), "/zipped_typeshed.zip"));
-
-pub fn file_system() -> &'static VendoredFileSystem {
-    static VENDORED_TYPESHED_STUBS: LazyLock<VendoredFileSystem> =
-        LazyLock::new(|| VendoredFileSystem::new_static(TYPESHED_ZIP_BYTES).unwrap());
-    &VENDORED_TYPESHED_STUBS
-}
+pub(crate) use versions::{
+    parse_typeshed_versions, LazyTypeshedVersions, TypeshedVersionsQueryResult,
+};
+pub use versions::{TypeshedVersionsParseError, TypeshedVersionsParseErrorKind};
 
 #[cfg(test)]
 mod tests {
     use std::io::{self, Read};
     use std::path::Path;
 
-    use ruff_db::vendored::VendoredPath;
+    use ruff_db::vendored::VendoredFileSystem;
+    use ruff_db::vfs::VendoredPath;
 
-    use super::*;
+    // The file path here is hardcoded in this crate's `build.rs` script.
+    // Luckily this crate will fail to build if this file isn't available at build time.
+    const TYPESHED_ZIP_BYTES: &[u8] =
+        include_bytes!(concat!(env!("OUT_DIR"), "/zipped_typeshed.zip"));
 
     #[test]
     fn typeshed_zip_created_at_build_time() {
@@ -41,7 +39,7 @@ mod tests {
     #[test]
     fn typeshed_vfs_consistent_with_vendored_stubs() {
         let vendored_typeshed_dir = Path::new("vendor/typeshed").canonicalize().unwrap();
-        let vendored_typeshed_stubs = file_system();
+        let vendored_typeshed_stubs = VendoredFileSystem::new(TYPESHED_ZIP_BYTES).unwrap();
 
         let mut empty_iterator = true;
         for entry in walkdir::WalkDir::new(&vendored_typeshed_dir).min_depth(1) {
@@ -71,7 +69,7 @@ mod tests {
 
             let vendored_path_kind = vendored_typeshed_stubs
                 .metadata(vendored_path)
-                .unwrap_or_else(|_| {
+                .unwrap_or_else(|| {
                     panic!(
                         "Expected metadata for {vendored_path:?} to be retrievable from the `VendoredFileSystem!
 

crates/red_knot_module_resolver/src/typeshed/versions.rs

@@ -1,31 +1,77 @@
+use std::cell::OnceCell;
 use std::collections::BTreeMap;
 use std::fmt;
 use std::num::{NonZeroU16, NonZeroUsize};
 use std::ops::{RangeFrom, RangeInclusive};
 use std::str::FromStr;
 
-use ruff_python_ast::PythonVersion;
+use ruff_db::file_system::FileSystemPath;
+use ruff_db::source::source_text;
+use ruff_db::vfs::{system_path_to_file, VfsFile};
 use rustc_hash::FxHashMap;
 
 use crate::db::Db;
 use crate::module_name::ModuleName;
-use crate::Program;
+use crate::supported_py_version::TargetVersion;
 
-pub(in crate::module_resolver) fn vendored_typeshed_versions(db: &dyn Db) -> TypeshedVersions {
-    TypeshedVersions::from_str(
-        &db.vendored()
-            .read_to_string("stdlib/VERSIONS")
-            .expect("The vendored typeshed stubs should contain a VERSIONS file"),
-    )
-    .expect("The VERSIONS file in the vendored typeshed stubs should be well-formed")
+#[derive(Debug)]
+pub(crate) struct LazyTypeshedVersions<'db>(OnceCell<&'db TypeshedVersions>);
+
+impl<'db> LazyTypeshedVersions<'db> {
+    #[must_use]
+    pub(crate) fn new() -> Self {
+        Self(OnceCell::new())
+    }
+
+    /// Query whether a module exists at runtime in the stdlib on a certain Python version.
+    ///
+    /// Simply probing whether a file exists in typeshed is insufficient for this question,
+    /// as a module in the stdlib may have been added in Python 3.10, but the typeshed stub
+    /// will still be available (either in a custom typeshed dir or in our vendored copy)
+    /// even if the user specified Python 3.8 as the target version.
+    ///
+    /// For top-level modules and packages, the VERSIONS file can always provide an unambiguous answer
+    /// as to whether the module exists on the specified target version. However, VERSIONS does not
+    /// provide comprehensive information on all submodules, meaning that this method sometimes
+    /// returns [`TypeshedVersionsQueryResult::MaybeExists`].
+    /// See [`TypeshedVersionsQueryResult`] for more details.
+    #[must_use]
+    pub(crate) fn query_module(
+        &self,
+        module: &ModuleName,
+        db: &'db dyn Db,
+        stdlib_root: &FileSystemPath,
+        target_version: TargetVersion,
+    ) -> TypeshedVersionsQueryResult {
+        let versions = self.0.get_or_init(|| {
+            let versions_path = stdlib_root.join("VERSIONS");
+            let Some(versions_file) = system_path_to_file(db.upcast(), &versions_path) else {
+                todo!(
+                    "Still need to figure out how to handle VERSIONS files being deleted \
+                    from custom typeshed directories! Expected a file to exist at {versions_path}"
+                )
+            };
+            // TODO(Alex/Micha): If VERSIONS is invalid,
+            // this should invalidate not just the specific module resolution we're currently attempting,
+            // but all type inference that depends on any standard-library types.
+            // Unwrapping here is not correct...
+            parse_typeshed_versions(db, versions_file).as_ref().unwrap()
+        });
+        versions.query_module(module, PyVersion::from(target_version))
+    }
 }
 
-pub(crate) fn typeshed_versions(db: &dyn Db) -> &TypeshedVersions {
-    Program::get(db).search_paths(db).typeshed_versions()
+#[salsa::tracked(return_ref)]
+pub(crate) fn parse_typeshed_versions(
+    db: &dyn Db,
+    versions_file: VfsFile,
+) -> Result<TypeshedVersions, TypeshedVersionsParseError> {
+    let file_content = source_text(db.upcast(), versions_file);
+    file_content.parse()
 }
 
 #[derive(Debug, PartialEq, Eq, Clone)]
-pub(crate) struct TypeshedVersionsParseError {
+pub struct TypeshedVersionsParseError {
     line_number: Option<NonZeroU16>,
     reason: TypeshedVersionsParseErrorKind,
 }
@@ -58,7 +104,7 @@ impl std::error::Error for TypeshedVersionsParseError {
 }
 
 #[derive(Debug, PartialEq, Eq, Clone)]
-pub(super) enum TypeshedVersionsParseErrorKind {
+pub enum TypeshedVersionsParseErrorKind {
     TooManyLines(NonZeroUsize),
     UnexpectedNumberOfColons,
     InvalidModuleName(String),
@@ -68,6 +114,7 @@ pub(super) enum TypeshedVersionsParseErrorKind {
         version: String,
         err: std::num::ParseIntError,
     },
+    EmptyVersionsFile,
 }
 
 impl fmt::Display for TypeshedVersionsParseErrorKind {
@@ -96,6 +143,7 @@ impl fmt::Display for TypeshedVersionsParseErrorKind {
                 f,
                 "Failed to convert '{version}' to a pair of integers due to {err}",
             ),
+            Self::EmptyVersionsFile => f.write_str("Versions file was empty!"),
         }
     }
 }
@@ -110,13 +158,13 @@ impl TypeshedVersions {
     }
 
     #[must_use]
-    pub(in crate::module_resolver) fn query_module(
+    fn query_module(
         &self,
         module: &ModuleName,
-        python_version: PythonVersion,
+        target_version: PyVersion,
     ) -> TypeshedVersionsQueryResult {
         if let Some(range) = self.exact(module) {
-            if range.contains(python_version) {
+            if range.contains(target_version) {
                 TypeshedVersionsQueryResult::Exists
             } else {
                 TypeshedVersionsQueryResult::DoesNotExist
@@ -126,7 +174,7 @@ impl TypeshedVersions {
             while let Some(module_to_try) = module {
                 if let Some(range) = self.exact(&module_to_try) {
                     return {
-                        if range.contains(python_version) {
+                        if range.contains(target_version) {
                             TypeshedVersionsQueryResult::MaybeExists
                         } else {
                             TypeshedVersionsQueryResult::DoesNotExist
@@ -140,7 +188,7 @@ impl TypeshedVersions {
     }
 }
 
-/// Possible answers [`TypeshedVersions::query_module()`] could give to the question:
+/// Possible answers [`LazyTypeshedVersions::query_module()`] could give to the question:
 /// "Does this module exist in the stdlib at runtime on a certain target version?"
 #[derive(Debug, Copy, PartialEq, Eq, Clone, Hash)]
 pub(crate) enum TypeshedVersionsQueryResult {
@@ -242,7 +290,14 @@ impl FromStr for TypeshedVersions {
             };
         }
 
-        Ok(Self(map))
+        if map.is_empty() {
+            Err(TypeshedVersionsParseError {
+                line_number: None,
+                reason: TypeshedVersionsParseErrorKind::EmptyVersionsFile,
+            })
+        } else {
+            Ok(Self(map))
+        }
     }
 }
 
@@ -258,13 +313,13 @@ impl fmt::Display for TypeshedVersions {
 
 #[derive(Debug, Clone, Eq, PartialEq, Hash)]
 enum PyVersionRange {
-    AvailableFrom(RangeFrom<PythonVersion>),
-    AvailableWithin(RangeInclusive<PythonVersion>),
+    AvailableFrom(RangeFrom<PyVersion>),
+    AvailableWithin(RangeInclusive<PyVersion>),
 }
 
 impl PyVersionRange {
     #[must_use]
-    fn contains(&self, version: PythonVersion) -> bool {
+    fn contains(&self, version: PyVersion) -> bool {
         match self {
             Self::AvailableFrom(inner) => inner.contains(&version),
             Self::AvailableWithin(inner) => inner.contains(&version),
@@ -278,14 +333,9 @@ impl FromStr for PyVersionRange {
     fn from_str(s: &str) -> Result<Self, Self::Err> {
         let mut parts = s.split('-').map(str::trim);
         match (parts.next(), parts.next(), parts.next()) {
-            (Some(lower), Some(""), None) => {
-                let lower = python_version_from_versions_file_string(lower)?;
-                Ok(Self::AvailableFrom(lower..))
-            }
+            (Some(lower), Some(""), None) => Ok(Self::AvailableFrom((lower.parse()?)..)),
             (Some(lower), Some(upper), None) => {
-                let lower = python_version_from_versions_file_string(lower)?;
-                let upper = python_version_from_versions_file_string(upper)?;
-                Ok(Self::AvailableWithin(lower..=upper))
+                Ok(Self::AvailableWithin((lower.parse()?)..=(upper.parse()?)))
             }
             _ => Err(TypeshedVersionsParseErrorKind::UnexpectedNumberOfHyphens),
         }
@@ -303,38 +353,90 @@ impl fmt::Display for PyVersionRange {
     }
 }
 
-fn python_version_from_versions_file_string(
-    s: &str,
-) -> Result<PythonVersion, TypeshedVersionsParseErrorKind> {
-    let mut parts = s.split('.').map(str::trim);
-    let (Some(major), Some(minor), None) = (parts.next(), parts.next(), parts.next()) else {
-        return Err(TypeshedVersionsParseErrorKind::UnexpectedNumberOfPeriods(
-            s.to_string(),
-        ));
-    };
-    PythonVersion::try_from((major, minor)).map_err(|int_parse_error| {
-        TypeshedVersionsParseErrorKind::IntegerParsingFailure {
-            version: s.to_string(),
-            err: int_parse_error,
+#[derive(Debug, Clone, Copy, Eq, PartialEq, Ord, PartialOrd, Hash)]
+struct PyVersion {
+    major: u8,
+    minor: u8,
+}
+
+impl FromStr for PyVersion {
+    type Err = TypeshedVersionsParseErrorKind;
+
+    fn from_str(s: &str) -> Result<Self, Self::Err> {
+        let mut parts = s.split('.').map(str::trim);
+        let (Some(major), Some(minor), None) = (parts.next(), parts.next(), parts.next()) else {
+            return Err(TypeshedVersionsParseErrorKind::UnexpectedNumberOfPeriods(
+                s.to_string(),
+            ));
+        };
+        let major = match u8::from_str(major) {
+            Ok(major) => major,
+            Err(err) => {
+                return Err(TypeshedVersionsParseErrorKind::IntegerParsingFailure {
+                    version: s.to_string(),
+                    err,
+                })
+            }
+        };
+        let minor = match u8::from_str(minor) {
+            Ok(minor) => minor,
+            Err(err) => {
+                return Err(TypeshedVersionsParseErrorKind::IntegerParsingFailure {
+                    version: s.to_string(),
+                    err,
+                })
+            }
+        };
+        Ok(Self { major, minor })
+    }
+}
+
+impl fmt::Display for PyVersion {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        let PyVersion { major, minor } = self;
+        write!(f, "{major}.{minor}")
+    }
+}
+
+impl From<TargetVersion> for PyVersion {
+    fn from(value: TargetVersion) -> Self {
+        match value {
+            TargetVersion::Py37 => PyVersion { major: 3, minor: 7 },
+            TargetVersion::Py38 => PyVersion { major: 3, minor: 8 },
+            TargetVersion::Py39 => PyVersion { major: 3, minor: 9 },
+            TargetVersion::Py310 => PyVersion {
+                major: 3,
+                minor: 10,
+            },
+            TargetVersion::Py311 => PyVersion {
+                major: 3,
+                minor: 11,
+            },
+            TargetVersion::Py312 => PyVersion {
+                major: 3,
+                minor: 12,
+            },
+            TargetVersion::Py313 => PyVersion {
+                major: 3,
+                minor: 13,
+            },
         }
-    })
+    }
 }
 
 #[cfg(test)]
 mod tests {
-    use std::fmt::Write as _;
     use std::num::{IntErrorKind, NonZeroU16};
     use std::path::Path;
 
-    use insta::assert_snapshot;
-
-    use crate::db::tests::TestDb;
-
     use super::*;
 
+    use insta::assert_snapshot;
+
     const TYPESHED_STDLIB_DIR: &str = "stdlib";
 
-    const ONE: Option<NonZeroU16> = Some(NonZeroU16::new(1).unwrap());
+    #[allow(unsafe_code)]
+    const ONE: Option<NonZeroU16> = Some(unsafe { NonZeroU16::new_unchecked(1) });
 
     impl TypeshedVersions {
         #[must_use]
@@ -350,9 +452,12 @@ mod tests {
 
     #[test]
     fn can_parse_vendored_versions_file() {
-        let db = TestDb::new();
+        let versions_data = include_str!(concat!(
+            env!("CARGO_MANIFEST_DIR"),
+            "/vendor/typeshed/stdlib/VERSIONS"
+        ));
 
-        let versions = vendored_typeshed_versions(&db);
+        let versions = TypeshedVersions::from_str(versions_data).unwrap();
         assert!(versions.len() > 100);
         assert!(versions.len() < 1000);
 
@@ -362,37 +467,36 @@ mod tests {
 
         assert!(versions.contains_exact(&asyncio));
         assert_eq!(
-            versions.query_module(&asyncio, PythonVersion::PY310),
+            versions.query_module(&asyncio, TargetVersion::Py310.into()),
             TypeshedVersionsQueryResult::Exists
         );
 
         assert!(versions.contains_exact(&asyncio_staggered));
         assert_eq!(
-            versions.query_module(&asyncio_staggered, PythonVersion::PY38),
+            versions.query_module(&asyncio_staggered, TargetVersion::Py38.into()),
             TypeshedVersionsQueryResult::Exists
         );
         assert_eq!(
-            versions.query_module(&asyncio_staggered, PythonVersion::PY37),
+            versions.query_module(&asyncio_staggered, TargetVersion::Py37.into()),
             TypeshedVersionsQueryResult::DoesNotExist
         );
 
         assert!(versions.contains_exact(&audioop));
         assert_eq!(
-            versions.query_module(&audioop, PythonVersion::PY312),
+            versions.query_module(&audioop, TargetVersion::Py312.into()),
             TypeshedVersionsQueryResult::Exists
         );
         assert_eq!(
-            versions.query_module(&audioop, PythonVersion::PY313),
+            versions.query_module(&audioop, TargetVersion::Py313.into()),
             TypeshedVersionsQueryResult::DoesNotExist
         );
     }
 
     #[test]
     fn typeshed_versions_consistent_with_vendored_stubs() {
-        let db = TestDb::new();
-        let vendored_typeshed_versions = vendored_typeshed_versions(&db);
-        let vendored_typeshed_dir =
-            Path::new(env!("CARGO_MANIFEST_DIR")).join("../red_knot_vendored/vendor/typeshed");
+        const VERSIONS_DATA: &str = include_str!("../../vendor/typeshed/stdlib/VERSIONS");
+        let vendored_typeshed_dir = Path::new("vendor/typeshed").canonicalize().unwrap();
+        let vendored_typeshed_versions = TypeshedVersions::from_str(VERSIONS_DATA).unwrap();
 
         let mut empty_iterator = true;
 
@@ -460,11 +564,11 @@ foo: 3.8-   # trailing comment
 ";
         let parsed_versions = TypeshedVersions::from_str(VERSIONS).unwrap();
         assert_eq!(parsed_versions.len(), 3);
-        assert_snapshot!(parsed_versions.to_string(), @r"
+        assert_snapshot!(parsed_versions.to_string(), @r###"
         bar: 2.7-3.10
         bar.baz: 3.1-3.9
         foo: 3.8-
-        "
+        "###
         );
     }
 
@@ -475,15 +579,15 @@ foo: 3.8-   # trailing comment
 
         assert!(parsed_versions.contains_exact(&bar));
         assert_eq!(
-            parsed_versions.query_module(&bar, PythonVersion::PY37),
+            parsed_versions.query_module(&bar, TargetVersion::Py37.into()),
             TypeshedVersionsQueryResult::Exists
         );
         assert_eq!(
-            parsed_versions.query_module(&bar, PythonVersion::PY310),
+            parsed_versions.query_module(&bar, TargetVersion::Py310.into()),
             TypeshedVersionsQueryResult::Exists
         );
         assert_eq!(
-            parsed_versions.query_module(&bar, PythonVersion::PY311),
+            parsed_versions.query_module(&bar, TargetVersion::Py311.into()),
             TypeshedVersionsQueryResult::DoesNotExist
         );
     }
@@ -495,15 +599,15 @@ foo: 3.8-   # trailing comment
 
         assert!(parsed_versions.contains_exact(&foo));
         assert_eq!(
-            parsed_versions.query_module(&foo, PythonVersion::PY37),
+            parsed_versions.query_module(&foo, TargetVersion::Py37.into()),
             TypeshedVersionsQueryResult::DoesNotExist
         );
         assert_eq!(
-            parsed_versions.query_module(&foo, PythonVersion::PY38),
+            parsed_versions.query_module(&foo, TargetVersion::Py38.into()),
             TypeshedVersionsQueryResult::Exists
         );
         assert_eq!(
-            parsed_versions.query_module(&foo, PythonVersion::PY311),
+            parsed_versions.query_module(&foo, TargetVersion::Py311.into()),
             TypeshedVersionsQueryResult::Exists
         );
     }
@@ -515,15 +619,15 @@ foo: 3.8-   # trailing comment
 
         assert!(parsed_versions.contains_exact(&bar_baz));
         assert_eq!(
-            parsed_versions.query_module(&bar_baz, PythonVersion::PY37),
+            parsed_versions.query_module(&bar_baz, TargetVersion::Py37.into()),
             TypeshedVersionsQueryResult::Exists
         );
         assert_eq!(
-            parsed_versions.query_module(&bar_baz, PythonVersion::PY39),
+            parsed_versions.query_module(&bar_baz, TargetVersion::Py39.into()),
             TypeshedVersionsQueryResult::Exists
         );
         assert_eq!(
-            parsed_versions.query_module(&bar_baz, PythonVersion::PY310),
+            parsed_versions.query_module(&bar_baz, TargetVersion::Py310.into()),
             TypeshedVersionsQueryResult::DoesNotExist
         );
     }
@@ -535,15 +639,15 @@ foo: 3.8-   # trailing comment
 
         assert!(!parsed_versions.contains_exact(&bar_eggs));
         assert_eq!(
-            parsed_versions.query_module(&bar_eggs, PythonVersion::PY37),
+            parsed_versions.query_module(&bar_eggs, TargetVersion::Py37.into()),
             TypeshedVersionsQueryResult::MaybeExists
         );
         assert_eq!(
-            parsed_versions.query_module(&bar_eggs, PythonVersion::PY310),
+            parsed_versions.query_module(&bar_eggs, TargetVersion::Py310.into()),
             TypeshedVersionsQueryResult::MaybeExists
         );
         assert_eq!(
-            parsed_versions.query_module(&bar_eggs, PythonVersion::PY311),
+            parsed_versions.query_module(&bar_eggs, TargetVersion::Py311.into()),
             TypeshedVersionsQueryResult::DoesNotExist
         );
     }
@@ -555,15 +659,40 @@ foo: 3.8-   # trailing comment
 
         assert!(!parsed_versions.contains_exact(&spam));
         assert_eq!(
-            parsed_versions.query_module(&spam, PythonVersion::PY37),
+            parsed_versions.query_module(&spam, TargetVersion::Py37.into()),
             TypeshedVersionsQueryResult::DoesNotExist
         );
         assert_eq!(
-            parsed_versions.query_module(&spam, PythonVersion::PY313),
+            parsed_versions.query_module(&spam, TargetVersion::Py313.into()),
             TypeshedVersionsQueryResult::DoesNotExist
         );
     }
 
+    #[test]
+    fn invalid_empty_versions_file() {
+        assert_eq!(
+            TypeshedVersions::from_str(""),
+            Err(TypeshedVersionsParseError {
+                line_number: None,
+                reason: TypeshedVersionsParseErrorKind::EmptyVersionsFile
+            })
+        );
+        assert_eq!(
+            TypeshedVersions::from_str("       "),
+            Err(TypeshedVersionsParseError {
+                line_number: None,
+                reason: TypeshedVersionsParseErrorKind::EmptyVersionsFile
+            })
+        );
+        assert_eq!(
+            TypeshedVersions::from_str(" \n  \n  \n "),
+            Err(TypeshedVersionsParseError {
+                line_number: None,
+                reason: TypeshedVersionsParseErrorKind::EmptyVersionsFile
+            })
+        );
+    }
+
     #[test]
     fn invalid_huge_versions_file() {
         let offset = 100;
@@ -571,7 +700,7 @@ foo: 3.8-   # trailing comment
 
         let mut massive_versions_file = String::new();
         for i in 0..too_many {
-            let _ = writeln!(&mut massive_versions_file, "x{i}: 3.8-");
+            massive_versions_file.push_str(&format!("x{i}: 3.8-\n"));
         }
 
         assert_eq!(

crates/red_knot_module_resolver/vendor/typeshed/README.md

@@ -21,7 +21,7 @@ the project the stubs are for, but instead report them here to typeshed.**
 Further documentation on stub files, typeshed, and Python's typing system in
 general, can also be found at https://typing.readthedocs.io/en/latest/.
 
-Typeshed supports Python versions 3.9 to 3.13.
+Typeshed supports Python versions 3.8 and up.
 
 ## Using
 

crates/red_knot_module_resolver/vendor/typeshed/source_commit.txt

@@ -0,0 +1 @@
+dcab6e88883c629ede9637fb011958f8b4918f52

crates/red_knot_module_resolver/vendor/typeshed/stdlib/VERSIONS

@@ -20,53 +20,35 @@
 __future__: 3.0-
 __main__: 3.0-
 _ast: 3.0-
-_asyncio: 3.0-
 _bisect: 3.0-
-_blake2: 3.6-
 _bootlocale: 3.4-3.9
-_bz2: 3.3-
 _codecs: 3.0-
 _collections_abc: 3.3-
 _compat_pickle: 3.1-
 _compression: 3.5-
-_contextvars: 3.7-
 _csv: 3.0-
 _ctypes: 3.0-
 _curses: 3.0-
-_curses_panel: 3.0-
-_dbm: 3.0-
 _decimal: 3.3-
-_frozen_importlib: 3.0-
-_frozen_importlib_external: 3.5-
-_gdbm: 3.0-
-_hashlib: 3.0-
+_dummy_thread: 3.0-3.8
+_dummy_threading: 3.0-3.8
 _heapq: 3.0-
 _imp: 3.0-
 _interpchannels: 3.13-
-_interpqueues: 3.13-
-_interpreters: 3.13-
-_io: 3.0-
 _json: 3.0-
 _locale: 3.0-
 _lsprof: 3.0-
-_lzma: 3.3-
 _markupbase: 3.0-
-_msi: 3.0-3.12
-_multibytecodec: 3.0-
+_msi: 3.0-
 _operator: 3.4-
 _osx_support: 3.0-
-_pickle: 3.0-
 _posixsubprocess: 3.2-
 _py_abc: 3.7-
 _pydecimal: 3.5-
-_queue: 3.7-
 _random: 3.0-
 _sitebuiltins: 3.4-
 _socket: 3.0-  # present in 3.0 at runtime, but not in typeshed
-_sqlite3: 3.0-
-_ssl: 3.0-
 _stat: 3.4-
-_struct: 3.0-
 _thread: 3.0-
 _threading_local: 3.0-
 _tkinter: 3.0-
@@ -130,7 +112,6 @@ curses: 3.0-
 dataclasses: 3.7-
 datetime: 3.0-
 dbm: 3.0-
-dbm.sqlite3: 3.13-
 decimal: 3.0-
 difflib: 3.0-
 dis: 3.0-
@@ -138,13 +119,9 @@ distutils: 3.0-3.11
 distutils.command.bdist_msi: 3.0-3.10
 distutils.command.bdist_wininst: 3.0-3.9
 doctest: 3.0-
+dummy_threading: 3.0-3.8
 email: 3.0-
 encodings: 3.0-
-encodings.cp1125: 3.4-
-encodings.cp273: 3.4-
-encodings.cp858: 3.2-
-encodings.koi8_t: 3.5-
-encodings.kz1048: 3.5-
 ensurepip: 3.0-
 enum: 3.4-
 errno: 3.0-
@@ -176,15 +153,10 @@ imghdr: 3.0-3.12
 imp: 3.0-3.11
 importlib: 3.0-
 importlib._abc: 3.10-
-importlib._bootstrap: 3.0-
-importlib._bootstrap_external: 3.5-
 importlib.metadata: 3.8-
 importlib.metadata._meta: 3.10-
-importlib.metadata.diagnose: 3.13-
 importlib.readers: 3.10-
 importlib.resources: 3.7-
-importlib.resources._common: 3.11-
-importlib.resources._functional: 3.13-
 importlib.resources.abc: 3.11-
 importlib.resources.readers: 3.11-
 importlib.resources.simple: 3.11-

crates/red_knot_module_resolver/vendor/typeshed/stdlib/_codecs.pyi

@@ -2,13 +2,10 @@ import codecs
 import sys
 from _typeshed import ReadableBuffer
 from collections.abc import Callable
-from typing import Literal, final, overload, type_check_only
+from typing import Literal, overload
 from typing_extensions import TypeAlias
 
 # This type is not exposed; it is defined in unicodeobject.c
-# At runtime it calls itself builtins.EncodingMap
-@final
-@type_check_only
 class _EncodingMap:
     def size(self) -> int: ...
 
@@ -81,12 +78,26 @@ def escape_decode(data: str | ReadableBuffer, errors: str | None = None, /) -> t
 def escape_encode(data: bytes, errors: str | None = None, /) -> tuple[bytes, int]: ...
 def latin_1_decode(data: ReadableBuffer, errors: str | None = None, /) -> tuple[str, int]: ...
 def latin_1_encode(str: str, errors: str | None = None, /) -> tuple[bytes, int]: ...
-def raw_unicode_escape_decode(
-    data: str | ReadableBuffer, errors: str | None = None, final: bool = True, /
-) -> tuple[str, int]: ...
+
+if sys.version_info >= (3, 9):
+    def raw_unicode_escape_decode(
+        data: str | ReadableBuffer, errors: str | None = None, final: bool = True, /
+    ) -> tuple[str, int]: ...
+
+else:
+    def raw_unicode_escape_decode(data: str | ReadableBuffer, errors: str | None = None, /) -> tuple[str, int]: ...
+
 def raw_unicode_escape_encode(str: str, errors: str | None = None, /) -> tuple[bytes, int]: ...
 def readbuffer_encode(data: str | ReadableBuffer, errors: str | None = None, /) -> tuple[bytes, int]: ...
-def unicode_escape_decode(data: str | ReadableBuffer, errors: str | None = None, final: bool = True, /) -> tuple[str, int]: ...
+
+if sys.version_info >= (3, 9):
+    def unicode_escape_decode(
+        data: str | ReadableBuffer, errors: str | None = None, final: bool = True, /
+    ) -> tuple[str, int]: ...
+
+else:
+    def unicode_escape_decode(data: str | ReadableBuffer, errors: str | None = None, /) -> tuple[str, int]: ...
+
 def unicode_escape_encode(str: str, errors: str | None = None, /) -> tuple[bytes, int]: ...
 def utf_16_be_decode(data: ReadableBuffer, errors: str | None = None, final: bool = False, /) -> tuple[str, int]: ...
 def utf_16_be_encode(str: str, errors: str | None = None, /) -> tuple[bytes, int]: ...

crates/red_knot_module_resolver/vendor/typeshed/stdlib/_collections_abc.pyi

@@ -1,14 +1,14 @@
 import sys
 from abc import abstractmethod
 from types import MappingProxyType
-from typing import (  # noqa: Y022,Y038,UP035
+from typing import (  # noqa: Y022,Y038,Y057
     AbstractSet as Set,
     AsyncGenerator as AsyncGenerator,
     AsyncIterable as AsyncIterable,
     AsyncIterator as AsyncIterator,
     Awaitable as Awaitable,
+    ByteString as ByteString,
     Callable as Callable,
-    ClassVar,
     Collection as Collection,
     Container as Container,
     Coroutine as Coroutine,
@@ -59,12 +59,8 @@ __all__ = [
     "ValuesView",
     "Sequence",
     "MutableSequence",
+    "ByteString",
 ]
-if sys.version_info < (3, 14):
-    from typing import ByteString as ByteString  # noqa: Y057,UP035
-
-    __all__ += ["ByteString"]
-
 if sys.version_info >= (3, 12):
     __all__ += ["Buffer"]
 
@@ -74,17 +70,12 @@ _VT_co = TypeVar("_VT_co", covariant=True)  # Value type covariant containers.
 @final
 class dict_keys(KeysView[_KT_co], Generic[_KT_co, _VT_co]):  # undocumented
     def __eq__(self, value: object, /) -> bool: ...
-    def __reversed__(self) -> Iterator[_KT_co]: ...
-    __hash__: ClassVar[None]  # type: ignore[assignment]
-    if sys.version_info >= (3, 13):
-        def isdisjoint(self, other: Iterable[_KT_co], /) -> bool: ...
     if sys.version_info >= (3, 10):
         @property
         def mapping(self) -> MappingProxyType[_KT_co, _VT_co]: ...
 
 @final
 class dict_values(ValuesView[_VT_co], Generic[_KT_co, _VT_co]):  # undocumented
-    def __reversed__(self) -> Iterator[_VT_co]: ...
     if sys.version_info >= (3, 10):
         @property
         def mapping(self) -> MappingProxyType[_KT_co, _VT_co]: ...
@@ -92,10 +83,6 @@ class dict_values(ValuesView[_VT_co], Generic[_KT_co, _VT_co]):  # undocumented
 @final
 class dict_items(ItemsView[_KT_co, _VT_co]):  # undocumented
     def __eq__(self, value: object, /) -> bool: ...
-    def __reversed__(self) -> Iterator[tuple[_KT_co, _VT_co]]: ...
-    __hash__: ClassVar[None]  # type: ignore[assignment]
-    if sys.version_info >= (3, 13):
-        def isdisjoint(self, other: Iterable[tuple[_KT_co, _VT_co]], /) -> bool: ...
     if sys.version_info >= (3, 10):
         @property
         def mapping(self) -> MappingProxyType[_KT_co, _VT_co]: ...

crates/red_knot_module_resolver/vendor/typeshed/stdlib/_csv.pyi

@@ -0,0 +1,90 @@
+import sys
+from _typeshed import SupportsWrite
+from collections.abc import Iterable, Iterator
+from typing import Any, Final, Literal
+from typing_extensions import TypeAlias
+
+__version__: Final[str]
+
+QUOTE_ALL: Literal[1]
+QUOTE_MINIMAL: Literal[0]
+QUOTE_NONE: Literal[3]
+QUOTE_NONNUMERIC: Literal[2]
+if sys.version_info >= (3, 12):
+    QUOTE_STRINGS: Literal[4]
+    QUOTE_NOTNULL: Literal[5]
+
+# Ideally this would be `QUOTE_ALL | QUOTE_MINIMAL | QUOTE_NONE | QUOTE_NONNUMERIC`
+# However, using literals in situations like these can cause false-positives (see #7258)
+_QuotingType: TypeAlias = int
+
+class Error(Exception): ...
+
+class Dialect:
+    delimiter: str
+    quotechar: str | None
+    escapechar: str | None
+    doublequote: bool
+    skipinitialspace: bool
+    lineterminator: str
+    quoting: _QuotingType
+    strict: bool
+    def __init__(self) -> None: ...
+
+_DialectLike: TypeAlias = str | Dialect | type[Dialect]
+
+class _reader(Iterator[list[str]]):
+    @property
+    def dialect(self) -> Dialect: ...
+    line_num: int
+    def __next__(self) -> list[str]: ...
+
+class _writer:
+    @property
+    def dialect(self) -> Dialect: ...
+    def writerow(self, row: Iterable[Any]) -> Any: ...
+    def writerows(self, rows: Iterable[Iterable[Any]]) -> None: ...
+
+def writer(
+    csvfile: SupportsWrite[str],
+    dialect: _DialectLike = "excel",
+    *,
+    delimiter: str = ",",
+    quotechar: str | None = '"',
+    escapechar: str | None = None,
+    doublequote: bool = True,
+    skipinitialspace: bool = False,
+    lineterminator: str = "\r\n",
+    quoting: _QuotingType = 0,
+    strict: bool = False,
+) -> _writer: ...
+def reader(
+    csvfile: Iterable[str],
+    dialect: _DialectLike = "excel",
+    *,
+    delimiter: str = ",",
+    quotechar: str | None = '"',
+    escapechar: str | None = None,
+    doublequote: bool = True,
+    skipinitialspace: bool = False,
+    lineterminator: str = "\r\n",
+    quoting: _QuotingType = 0,
+    strict: bool = False,
+) -> _reader: ...
+def register_dialect(
+    name: str,
+    dialect: type[Dialect] = ...,
+    *,
+    delimiter: str = ",",
+    quotechar: str | None = '"',
+    escapechar: str | None = None,
+    doublequote: bool = True,
+    skipinitialspace: bool = False,
+    lineterminator: str = "\r\n",
+    quoting: _QuotingType = 0,
+    strict: bool = False,
+) -> None: ...
+def unregister_dialect(name: str) -> None: ...
+def get_dialect(name: str) -> Dialect: ...
+def list_dialects() -> list[str]: ...
+def field_size_limit(new_limit: int = ...) -> int: ...

crates/red_knot_module_resolver/vendor/typeshed/stdlib/_ctypes.pyi

@@ -0,0 +1,211 @@
+import sys
+from _typeshed import ReadableBuffer, WriteableBuffer
+from abc import abstractmethod
+from collections.abc import Callable, Iterable, Iterator, Mapping, Sequence
+from ctypes import CDLL, ArgumentError as ArgumentError
+from typing import Any, ClassVar, Generic, TypeVar, overload
+from typing_extensions import Self, TypeAlias
+
+if sys.version_info >= (3, 9):
+    from types import GenericAlias
+
+_T = TypeVar("_T")
+_CT = TypeVar("_CT", bound=_CData)
+
+FUNCFLAG_CDECL: int
+FUNCFLAG_PYTHONAPI: int
+FUNCFLAG_USE_ERRNO: int
+FUNCFLAG_USE_LASTERROR: int
+RTLD_GLOBAL: int
+RTLD_LOCAL: int
+
+if sys.version_info >= (3, 11):
+    CTYPES_MAX_ARGCOUNT: int
+
+if sys.version_info >= (3, 12):
+    SIZEOF_TIME_T: int
+
+if sys.platform == "win32":
+    # Description, Source, HelpFile, HelpContext, scode
+    _COMError_Details: TypeAlias = tuple[str | None, str | None, str | None, int | None, int | None]
+
+    class COMError(Exception):
+        hresult: int
+        text: str | None
+        details: _COMError_Details
+
+        def __init__(self, hresult: int, text: str | None, details: _COMError_Details) -> None: ...
+
+    def CopyComPointer(src: _PointerLike, dst: _PointerLike | _CArgObject) -> int: ...
+
+    FUNCFLAG_HRESULT: int
+    FUNCFLAG_STDCALL: int
+
+    def FormatError(code: int = ...) -> str: ...
+    def get_last_error() -> int: ...
+    def set_last_error(value: int) -> int: ...
+    def LoadLibrary(name: str, load_flags: int = 0, /) -> int: ...
+    def FreeLibrary(handle: int, /) -> None: ...
+
+class _CDataMeta(type):
+    # By default mypy complains about the following two methods, because strictly speaking cls
+    # might not be a Type[_CT]. However this can never actually happen, because the only class that
+    # uses _CDataMeta as its metaclass is _CData. So it's safe to ignore the errors here.
+    def __mul__(cls: type[_CT], other: int) -> type[Array[_CT]]: ...  # type: ignore[misc]
+    def __rmul__(cls: type[_CT], other: int) -> type[Array[_CT]]: ...  # type: ignore[misc]
+
+class _CData(metaclass=_CDataMeta):
+    _b_base_: int
+    _b_needsfree_: bool
+    _objects: Mapping[Any, int] | None
+    # At runtime the following classmethods are available only on classes, not
+    # on instances. This can't be reflected properly in the type system:
+    #
+    # Structure.from_buffer(...)  # valid at runtime
+    # Structure(...).from_buffer(...)  # invalid at runtime
+    #
+
+    @classmethod
+    def from_buffer(cls, source: WriteableBuffer, offset: int = ...) -> Self: ...
+    @classmethod
+    def from_buffer_copy(cls, source: ReadableBuffer, offset: int = ...) -> Self: ...
+    @classmethod
+    def from_address(cls, address: int) -> Self: ...
+    @classmethod
+    def from_param(cls, obj: Any) -> Self | _CArgObject: ...
+    @classmethod
+    def in_dll(cls, library: CDLL, name: str) -> Self: ...
+    def __buffer__(self, flags: int, /) -> memoryview: ...
+    def __release_buffer__(self, buffer: memoryview, /) -> None: ...
+
+class _SimpleCData(_CData, Generic[_T]):
+    value: _T
+    # The TypeVar can be unsolved here,
+    # but we can't use overloads without creating many, many mypy false-positive errors
+    def __init__(self, value: _T = ...) -> None: ...  # pyright: ignore[reportInvalidTypeVarUse]
+
+class _CanCastTo(_CData): ...
+class _PointerLike(_CanCastTo): ...
+
+class _Pointer(_PointerLike, _CData, Generic[_CT]):
+    _type_: type[_CT]
+    contents: _CT
+    @overload
+    def __init__(self) -> None: ...
+    @overload
+    def __init__(self, arg: _CT) -> None: ...
+    @overload
+    def __getitem__(self, key: int, /) -> Any: ...
+    @overload
+    def __getitem__(self, key: slice, /) -> list[Any]: ...
+    def __setitem__(self, key: int, value: Any, /) -> None: ...
+
+def POINTER(type: type[_CT]) -> type[_Pointer[_CT]]: ...
+def pointer(arg: _CT, /) -> _Pointer[_CT]: ...
+
+class _CArgObject: ...
+
+def byref(obj: _CData, offset: int = ...) -> _CArgObject: ...
+
+_ECT: TypeAlias = Callable[[_CData | None, CFuncPtr, tuple[_CData, ...]], _CData]
+_PF: TypeAlias = tuple[int] | tuple[int, str | None] | tuple[int, str | None, Any]
+
+class CFuncPtr(_PointerLike, _CData):
+    restype: type[_CData] | Callable[[int], Any] | None
+    argtypes: Sequence[type[_CData]]
+    errcheck: _ECT
+    # Abstract attribute that must be defined on subclasses
+    _flags_: ClassVar[int]
+    @overload
+    def __init__(self) -> None: ...
+    @overload
+    def __init__(self, address: int, /) -> None: ...
+    @overload
+    def __init__(self, callable: Callable[..., Any], /) -> None: ...
+    @overload
+    def __init__(self, func_spec: tuple[str | int, CDLL], paramflags: tuple[_PF, ...] | None = ..., /) -> None: ...
+    if sys.platform == "win32":
+        @overload
+        def __init__(
+            self, vtbl_index: int, name: str, paramflags: tuple[_PF, ...] | None = ..., iid: _CData | None = ..., /
+        ) -> None: ...
+
+    def __call__(self, *args: Any, **kwargs: Any) -> Any: ...
+
+_GetT = TypeVar("_GetT")
+_SetT = TypeVar("_SetT")
+
+class _CField(Generic[_CT, _GetT, _SetT]):
+    offset: int
+    size: int
+    @overload
+    def __get__(self, instance: None, owner: type[Any] | None, /) -> Self: ...
+    @overload
+    def __get__(self, instance: Any, owner: type[Any] | None, /) -> _GetT: ...
+    def __set__(self, instance: Any, value: _SetT, /) -> None: ...
+
+class _StructUnionMeta(_CDataMeta):
+    _fields_: Sequence[tuple[str, type[_CData]] | tuple[str, type[_CData], int]]
+    _pack_: int
+    _anonymous_: Sequence[str]
+    def __getattr__(self, name: str) -> _CField[Any, Any, Any]: ...
+
+class _StructUnionBase(_CData, metaclass=_StructUnionMeta):
+    def __init__(self, *args: Any, **kw: Any) -> None: ...
+    def __getattr__(self, name: str) -> Any: ...
+    def __setattr__(self, name: str, value: Any) -> None: ...
+
+class Union(_StructUnionBase): ...
+class Structure(_StructUnionBase): ...
+
+class Array(_CData, Generic[_CT]):
+    @property
+    @abstractmethod
+    def _length_(self) -> int: ...
+    @_length_.setter
+    def _length_(self, value: int) -> None: ...
+    @property
+    @abstractmethod
+    def _type_(self) -> type[_CT]: ...
+    @_type_.setter
+    def _type_(self, value: type[_CT]) -> None: ...
+    # Note: only available if _CT == c_char
+    @property
+    def raw(self) -> bytes: ...
+    @raw.setter
+    def raw(self, value: ReadableBuffer) -> None: ...
+    value: Any  # Note: bytes if _CT == c_char, str if _CT == c_wchar, unavailable otherwise
+    # TODO These methods cannot be annotated correctly at the moment.
+    # All of these "Any"s stand for the array's element type, but it's not possible to use _CT
+    # here, because of a special feature of ctypes.
+    # By default, when accessing an element of an Array[_CT], the returned object has type _CT.
+    # However, when _CT is a "simple type" like c_int, ctypes automatically "unboxes" the object
+    # and converts it to the corresponding Python primitive. For example, when accessing an element
+    # of an Array[c_int], a Python int object is returned, not a c_int.
+    # This behavior does *not* apply to subclasses of "simple types".
+    # If MyInt is a subclass of c_int, then accessing an element of an Array[MyInt] returns
+    # a MyInt, not an int.
+    # This special behavior is not easy to model in a stub, so for now all places where
+    # the array element type would belong are annotated with Any instead.
+    def __init__(self, *args: Any) -> None: ...
+    @overload
+    def __getitem__(self, key: int, /) -> Any: ...
+    @overload
+    def __getitem__(self, key: slice, /) -> list[Any]: ...
+    @overload
+    def __setitem__(self, key: int, value: Any, /) -> None: ...
+    @overload
+    def __setitem__(self, key: slice, value: Iterable[Any], /) -> None: ...
+    def __iter__(self) -> Iterator[Any]: ...
+    # Can't inherit from Sized because the metaclass conflict between
+    # Sized and _CData prevents using _CDataMeta.
+    def __len__(self) -> int: ...
+    if sys.version_info >= (3, 9):
+        def __class_getitem__(cls, item: Any, /) -> GenericAlias: ...
+
+def addressof(obj: _CData) -> int: ...
+def alignment(obj_or_type: _CData | type[_CData]) -> int: ...
+def get_errno() -> int: ...
+def resize(obj: _CData, size: int) -> None: ...
+def set_errno(value: int) -> int: ...
+def sizeof(obj_or_type: _CData | type[_CData]) -> int: ...