Make CallArguments salsa::interned

.github/CODEOWNERS

@@ -18,7 +18,6 @@
 /python/py-fuzzer/ @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 @sharkdp
+/crates/ruff_db/ @carljm @MichaReiser @AlexWaygood @sharkdp
+/scripts/knot_benchmark/ @carljm @MichaReiser @AlexWaygood @sharkdp

.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 +1,2 @@
-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.
+# This file cannot use the extension `.yaml`.
+blank_issues_enabled: false

.github/ISSUE_TEMPLATE/issue.yaml

@@ -0,0 +1,22 @@
+name: New issue
+description: A generic issue
+
+body:
+  - type: markdown
+    attributes:
+      value: |
+        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`).
+
+  - type: textarea
+    attributes:
+      label: Description
+      description: A description of the issue

.github/renovate.json5

@@ -40,17 +40,6 @@
     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",
@@ -69,6 +58,12 @@
       description: "Disable PRs updating GitHub runners (e.g. 'runs-on: macos-14')",
       enabled: false,
     },
+    {
+      // TODO: Remove this once the codebase is upgrade to v4 (https://github.com/astral-sh/ruff/pull/16069)
+      matchPackageNames: ["tailwindcss"],
+      matchManagers: ["npm"],
+      enabled: false,
+    },
     {
       // Disable updates of `zip-rs`; intentionally pinned for now due to ownership change
       // See: https://github.com/astral-sh/uv/issues/3642
@@ -106,7 +101,14 @@
       matchManagers: ["cargo"],
       matchPackageNames: ["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

@@ -28,7 +28,7 @@ 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
@@ -39,17 +39,17 @@ jobs:
     if: ${{ !contains(github.event.pull_request.labels.*.name, 'no-build') }}
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4
+      - uses: actions/checkout@v4
         with:
           submodules: recursive
           persist-credentials: false
-      - uses: actions/setup-python@8d9ed9ac5c53483de85588cdf95a591a75ab9f55 # v5
+      - uses: actions/setup-python@v5
         with:
           python-version: ${{ env.PYTHON_VERSION }}
       - name: "Prep README.md"
         run: python scripts/transform_readme.py --target pypi
       - name: "Build sdist"
-        uses: PyO3/maturin-action@22fe573c6ed0c03ab9b84e631cbfa49bddf6e20e # v1.47.3
+        uses: PyO3/maturin-action@v1
         with:
           command: sdist
           args: --out dist
@@ -59,7 +59,7 @@ jobs:
           "${MODULE_NAME}" --help
           python -m "${MODULE_NAME}" --help
       - name: "Upload sdist"
-        uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02 # v4
+        uses: actions/upload-artifact@v4
         with:
           name: wheels-sdist
           path: dist
@@ -68,23 +68,23 @@ jobs:
     if: ${{ !contains(github.event.pull_request.labels.*.name, 'no-build') }}
     runs-on: macos-14
     steps:
-      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4
+      - uses: actions/checkout@v4
         with:
           submodules: recursive
           persist-credentials: false
-      - uses: actions/setup-python@8d9ed9ac5c53483de85588cdf95a591a75ab9f55 # v5
+      - 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@22fe573c6ed0c03ab9b84e631cbfa49bddf6e20e # v1.47.3
+        uses: PyO3/maturin-action@v1
         with:
           target: x86_64
           args: --release --locked --out dist
       - name: "Upload wheels"
-        uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02 # v4
+        uses: actions/upload-artifact@v4
         with:
           name: wheels-macos-x86_64
           path: dist
@@ -99,7 +99,7 @@ jobs:
           tar czvf $ARCHIVE_FILE $ARCHIVE_NAME
           shasum -a 256 $ARCHIVE_FILE > $ARCHIVE_FILE.sha256
       - name: "Upload binary"
-        uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02 # v4
+        uses: actions/upload-artifact@v4
         with:
           name: artifacts-macos-x86_64
           path: |
@@ -110,18 +110,18 @@ jobs:
     if: ${{ !contains(github.event.pull_request.labels.*.name, 'no-build') }}
     runs-on: macos-14
     steps:
-      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4
+      - uses: actions/checkout@v4
         with:
           submodules: recursive
           persist-credentials: false
-      - uses: actions/setup-python@8d9ed9ac5c53483de85588cdf95a591a75ab9f55 # v5
+      - 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@22fe573c6ed0c03ab9b84e631cbfa49bddf6e20e # v1.47.3
+        uses: PyO3/maturin-action@v1
         with:
           target: aarch64
           args: --release --locked --out dist
@@ -131,7 +131,7 @@ jobs:
           ruff --help
           python -m ruff --help
       - name: "Upload wheels"
-        uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02 # v4
+        uses: actions/upload-artifact@v4
         with:
           name: wheels-aarch64-apple-darwin
           path: dist
@@ -146,7 +146,7 @@ jobs:
           tar czvf $ARCHIVE_FILE $ARCHIVE_NAME
           shasum -a 256 $ARCHIVE_FILE > $ARCHIVE_FILE.sha256
       - name: "Upload binary"
-        uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02 # v4
+        uses: actions/upload-artifact@v4
         with:
           name: artifacts-aarch64-apple-darwin
           path: |
@@ -166,18 +166,18 @@ jobs:
           - target: aarch64-pc-windows-msvc
             arch: x64
     steps:
-      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4
+      - uses: actions/checkout@v4
         with:
           submodules: recursive
           persist-credentials: false
-      - uses: actions/setup-python@8d9ed9ac5c53483de85588cdf95a591a75ab9f55 # v5
+      - 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@22fe573c6ed0c03ab9b84e631cbfa49bddf6e20e # v1.47.3
+        uses: PyO3/maturin-action@v1
         with:
           target: ${{ matrix.platform.target }}
           args: --release --locked --out dist
@@ -192,7 +192,7 @@ jobs:
           "${MODULE_NAME}" --help
           python -m "${MODULE_NAME}" --help
       - name: "Upload wheels"
-        uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02 # v4
+        uses: actions/upload-artifact@v4
         with:
           name: wheels-${{ matrix.platform.target }}
           path: dist
@@ -203,7 +203,7 @@ jobs:
           7z a $ARCHIVE_FILE ./target/${{ matrix.platform.target }}/release/ruff.exe
           sha256sum $ARCHIVE_FILE > $ARCHIVE_FILE.sha256
       - name: "Upload binary"
-        uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02 # v4
+        uses: actions/upload-artifact@v4
         with:
           name: artifacts-${{ matrix.platform.target }}
           path: |
@@ -219,18 +219,18 @@ jobs:
           - x86_64-unknown-linux-gnu
           - i686-unknown-linux-gnu
     steps:
-      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4
+      - uses: actions/checkout@v4
         with:
           submodules: recursive
           persist-credentials: false
-      - uses: actions/setup-python@8d9ed9ac5c53483de85588cdf95a591a75ab9f55 # v5
+      - 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@22fe573c6ed0c03ab9b84e631cbfa49bddf6e20e # v1.47.3
+        uses: PyO3/maturin-action@v1
         with:
           target: ${{ matrix.target }}
           manylinux: auto
@@ -242,7 +242,7 @@ jobs:
           "${MODULE_NAME}" --help
           python -m "${MODULE_NAME}" --help
       - name: "Upload wheels"
-        uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02 # v4
+        uses: actions/upload-artifact@v4
         with:
           name: wheels-${{ matrix.target }}
           path: dist
@@ -260,7 +260,7 @@ jobs:
           tar czvf $ARCHIVE_FILE $ARCHIVE_NAME
           shasum -a 256 $ARCHIVE_FILE > $ARCHIVE_FILE.sha256
       - name: "Upload binary"
-        uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02 # v4
+        uses: actions/upload-artifact@v4
         with:
           name: artifacts-${{ matrix.target }}
           path: |
@@ -294,24 +294,24 @@ jobs:
             arch: arm
 
     steps:
-      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4
+      - uses: actions/checkout@v4
         with:
           submodules: recursive
           persist-credentials: false
-      - uses: actions/setup-python@8d9ed9ac5c53483de85588cdf95a591a75ab9f55 # v5
+      - 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@22fe573c6ed0c03ab9b84e631cbfa49bddf6e20e # v1.47.3
+        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 +325,7 @@ jobs:
             pip3 install ${{ env.PACKAGE_NAME }} --no-index --find-links dist/ --force-reinstall
             ruff --help
       - name: "Upload wheels"
-        uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02 # v4
+        uses: actions/upload-artifact@v4
         with:
           name: wheels-${{ matrix.platform.target }}
           path: dist
@@ -343,7 +343,7 @@ jobs:
           tar czvf $ARCHIVE_FILE $ARCHIVE_NAME
           shasum -a 256 $ARCHIVE_FILE > $ARCHIVE_FILE.sha256
       - name: "Upload binary"
-        uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02 # v4
+        uses: actions/upload-artifact@v4
         with:
           name: artifacts-${{ matrix.platform.target }}
           path: |
@@ -359,18 +359,18 @@ jobs:
           - x86_64-unknown-linux-musl
           - i686-unknown-linux-musl
     steps:
-      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4
+      - uses: actions/checkout@v4
         with:
           submodules: recursive
           persist-credentials: false
-      - uses: actions/setup-python@8d9ed9ac5c53483de85588cdf95a591a75ab9f55 # v5
+      - 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@22fe573c6ed0c03ab9b84e631cbfa49bddf6e20e # v1.47.3
+        uses: PyO3/maturin-action@v1
         with:
           target: ${{ matrix.target }}
           manylinux: musllinux_1_2
@@ -387,7 +387,7 @@ 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
+        uses: actions/upload-artifact@v4
         with:
           name: wheels-${{ matrix.target }}
           path: dist
@@ -405,7 +405,7 @@ jobs:
           tar czvf $ARCHIVE_FILE $ARCHIVE_NAME
           shasum -a 256 $ARCHIVE_FILE > $ARCHIVE_FILE.sha256
       - name: "Upload binary"
-        uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02 # v4
+        uses: actions/upload-artifact@v4
         with:
           name: artifacts-${{ matrix.target }}
           path: |
@@ -425,23 +425,23 @@ jobs:
             arch: armv7
 
     steps:
-      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4
+      - uses: actions/checkout@v4
         with:
           submodules: recursive
           persist-credentials: false
-      - uses: actions/setup-python@8d9ed9ac5c53483de85588cdf95a591a75ab9f55 # v5
+      - 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@22fe573c6ed0c03ab9b84e631cbfa49bddf6e20e # v1.47.3
+        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 +454,7 @@ 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
+        uses: actions/upload-artifact@v4
         with:
           name: wheels-${{ matrix.platform.target }}
           path: dist
@@ -472,7 +472,7 @@ jobs:
           tar czvf $ARCHIVE_FILE $ARCHIVE_NAME
           shasum -a 256 $ARCHIVE_FILE > $ARCHIVE_FILE.sha256
       - name: "Upload binary"
-        uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02 # v4
+        uses: actions/upload-artifact@v4
         with:
           name: artifacts-${{ matrix.platform.target }}
           path: |

.github/workflows/build-docker.yml

@@ -33,14 +33,14 @@ jobs:
           - linux/amd64
           - linux/arm64
     steps:
-      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4
+      - 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 }}
@@ -63,7 +63,7 @@ jobs:
 
       - name: Extract metadata (tags, labels) for Docker
         id: meta
-        uses: docker/metadata-action@902fa8ec7d6ecbf8d84d538b9b233a880e428804 # v5
+        uses: docker/metadata-action@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
@@ -79,7 +79,7 @@ jobs:
       # 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
+        uses: docker/build-push-action@v6
         with:
           context: .
           platforms: ${{ matrix.platform }}
@@ -96,7 +96,7 @@ jobs:
           touch "/tmp/digests/${digest#sha256:}"
 
       - name: Upload digests
-        uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02 # v4
+        uses: actions/upload-artifact@v4
         with:
           name: digests-${{ env.PLATFORM_TUPLE }}
           path: /tmp/digests/*
@@ -113,17 +113,17 @@ jobs:
     if: ${{ inputs.plan != '' && !fromJson(inputs.plan).announcement_tag_is_implicit }}
     steps:
       - name: Download digests
-        uses: actions/download-artifact@95815c38cf2ff2164869cbab79da8d1f422bc89e # v4
+        uses: actions/download-artifact@v4
         with:
           path: /tmp/digests
           pattern: digests-*
           merge-multiple: true
 
-      - uses: docker/setup-buildx-action@b5ca514318bd6ebac0fb2aedd5d36ec1b5c232a2 # v3
+      - uses: docker/setup-buildx-action@v3
 
       - name: Extract metadata (tags, labels) for Docker
         id: meta
-        uses: docker/metadata-action@902fa8ec7d6ecbf8d84d538b9b233a880e428804 # v5
+        uses: docker/metadata-action@v5
         with:
           images: ${{ env.RUFF_BASE_IMG }}
           # Order is on purpose such that the label org.opencontainers.image.version has the first pattern with the full version
@@ -131,7 +131,7 @@ jobs:
             type=pep440,pattern={{ version }},value=${{ fromJson(inputs.plan).announcement_tag }}
             type=pep440,pattern={{ major }}.{{ minor }},value=${{ fromJson(inputs.plan).announcement_tag }}
 
-      - uses: docker/login-action@74a5d142397b4f367a81961eba4e8cd7edddf772 # v3
+      - uses: docker/login-action@v3
         with:
           registry: ghcr.io
           username: ${{ github.repository_owner }}
@@ -163,13 +163,13 @@ jobs:
         # 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
+          - alpine:3.20,alpine3.20,alpine
           - debian:bookworm-slim,bookworm-slim,debian-slim
           - buildpack-deps:bookworm,bookworm,debian
     steps:
-      - 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 }}
@@ -219,7 +219,7 @@ jobs:
 
       - name: Extract metadata (tags, labels) for Docker
         id: meta
-        uses: docker/metadata-action@902fa8ec7d6ecbf8d84d538b9b233a880e428804 # v5
+        uses: docker/metadata-action@v5
         # ghcr.io prefers index level annotations
         env:
           DOCKER_METADATA_ANNOTATIONS_LEVELS: index
@@ -231,7 +231,7 @@ jobs:
             ${{ env.TAG_PATTERNS }}
 
       - name: Build and push
-        uses: docker/build-push-action@471d1dc4e07e5cdedd4c2171150001c434f0b7a4 # v6
+        uses: docker/build-push-action@v6
         with:
           context: .
           platforms: linux/amd64,linux/arm64
@@ -256,17 +256,17 @@ jobs:
     if: ${{ inputs.plan != '' && !fromJson(inputs.plan).announcement_tag_is_implicit }}
     steps:
       - name: Download digests
-        uses: actions/download-artifact@95815c38cf2ff2164869cbab79da8d1f422bc89e # v4
+        uses: actions/download-artifact@v4
         with:
           path: /tmp/digests
           pattern: digests-*
           merge-multiple: true
 
-      - uses: docker/setup-buildx-action@b5ca514318bd6ebac0fb2aedd5d36ec1b5c232a2 # v3
+      - uses: docker/setup-buildx-action@v3
 
       - name: Extract metadata (tags, labels) for Docker
         id: meta
-        uses: docker/metadata-action@902fa8ec7d6ecbf8d84d538b9b233a880e428804 # v5
+        uses: docker/metadata-action@v5
         env:
           DOCKER_METADATA_ANNOTATIONS_LEVELS: index
         with:
@@ -276,7 +276,7 @@ jobs:
             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
+      - uses: docker/login-action@v3
         with:
           registry: ghcr.io
           username: ${{ github.repository_owner }}

.github/workflows/ci.yaml

@@ -18,7 +18,7 @@ env:
   CARGO_TERM_COLOR: always
   RUSTUP_MAX_RETRIES: 10
   PACKAGE_NAME: ruff
-  PYTHON_VERSION: "3.13"
+  PYTHON_VERSION: "3.12"
 
 jobs:
   determine_changes:
@@ -26,177 +26,83 @@ 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 }}
+      code: ${{ steps.changed.outputs.code_any_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 }}
+      fuzz: ${{ steps.changed.outputs.fuzz_any_changed }}
     steps:
-      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4
+      - 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@v45
+        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/**
+              - python/py-fuzzer/**
+              - .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/red_knot*/**"
+              - "!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
+            fuzz:
+              - fuzz/Cargo.toml
+              - fuzz/Cargo.lock
+              - fuzz/fuzz_targets/**
 
-      - 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"
+              - "crates/red_knot_python_semantic/resources/mdtest/**/*.md"
+              - "!docs/**"
+              - "!assets/**"
 
   cargo-fmt:
     name: "cargo fmt"
     runs-on: ubuntu-latest
     timeout-minutes: 10
     steps:
-      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4
+      - uses: actions/checkout@v4
         with:
           persist-credentials: false
       - name: "Install Rust toolchain"
@@ -210,10 +116,10 @@ jobs:
     if: ${{ needs.determine_changes.outputs.code == 'true' || github.ref == 'refs/heads/main' }}
     timeout-minutes: 20
     steps:
-      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4
+      - uses: actions/checkout@v4
         with:
           persist-credentials: false
-      - uses: Swatinem/rust-cache@9d47c6ad4b02e050fd481d890b2ea34778fd09d6 # v2
+      - uses: Swatinem/rust-cache@v2
       - name: "Install Rust toolchain"
         run: |
           rustup component add clippy
@@ -230,30 +136,22 @@ jobs:
     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
+      - uses: actions/checkout@v4
         with:
           persist-credentials: false
-      - uses: Swatinem/rust-cache@9d47c6ad4b02e050fd481d890b2ea34778fd09d6 # v2
+      - uses: Swatinem/rust-cache@v2
       - name: "Install Rust toolchain"
         run: rustup show
       - name: "Install mold"
         uses: rui314/setup-mold@v1
       - name: "Install cargo nextest"
-        uses: taiki-e/install-action@6aca1cfa12ef3a6b98ee8c70e0171bfa067604f5 # v2
+        uses: taiki-e/install-action@v2
         with:
           tool: cargo-nextest
       - name: "Install cargo insta"
-        uses: taiki-e/install-action@6aca1cfa12ef3a6b98ee8c70e0171bfa067604f5 # 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
       - name: "Run tests"
         shell: bash
         env:
@@ -272,7 +170,7 @@ jobs:
         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
+      - uses: actions/upload-artifact@v4
         with:
           name: ruff
           path: target/debug/ruff
@@ -284,20 +182,20 @@ jobs:
     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
+      - uses: actions/checkout@v4
         with:
           persist-credentials: false
-      - uses: Swatinem/rust-cache@9d47c6ad4b02e050fd481d890b2ea34778fd09d6 # v2
+      - uses: Swatinem/rust-cache@v2
       - name: "Install Rust toolchain"
         run: rustup show
       - name: "Install mold"
         uses: rui314/setup-mold@v1
       - name: "Install cargo nextest"
-        uses: taiki-e/install-action@6aca1cfa12ef3a6b98ee8c70e0171bfa067604f5 # v2
+        uses: taiki-e/install-action@v2
         with:
           tool: cargo-nextest
       - name: "Install cargo insta"
-        uses: taiki-e/install-action@6aca1cfa12ef3a6b98ee8c70e0171bfa067604f5 # v2
+        uses: taiki-e/install-action@v2
         with:
           tool: cargo-insta
       - name: "Run tests"
@@ -313,14 +211,14 @@ jobs:
     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
+      - uses: actions/checkout@v4
         with:
           persist-credentials: false
-      - uses: Swatinem/rust-cache@9d47c6ad4b02e050fd481d890b2ea34778fd09d6 # v2
+      - uses: Swatinem/rust-cache@v2
       - name: "Install Rust toolchain"
         run: rustup show
       - name: "Install cargo nextest"
-        uses: taiki-e/install-action@6aca1cfa12ef3a6b98ee8c70e0171bfa067604f5 # v2
+        uses: taiki-e/install-action@v2
         with:
           tool: cargo-nextest
       - name: "Run tests"
@@ -340,18 +238,18 @@ jobs:
     if: ${{ !contains(github.event.pull_request.labels.*.name, 'no-test') && (needs.determine_changes.outputs.code == 'true' || github.ref == 'refs/heads/main') }}
     timeout-minutes: 10
     steps:
-      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4
+      - uses: actions/checkout@v4
         with:
           persist-credentials: false
-      - uses: Swatinem/rust-cache@9d47c6ad4b02e050fd481d890b2ea34778fd09d6 # v2
+      - uses: Swatinem/rust-cache@v2
       - name: "Install Rust toolchain"
         run: rustup target add wasm32-unknown-unknown
-      - uses: actions/setup-node@cdca7365b2dadb8aad0a33bc7601856ffabcc48e # v4
+      - uses: actions/setup-node@v4
         with:
           node-version: 20
           cache: "npm"
           cache-dependency-path: playground/package-lock.json
-      - uses: jetli/wasm-pack-action@0d096b08b4e5a7de8c28de67e11e945404e9eefa # v0.4.0
+      - uses: jetli/wasm-pack-action@v0.4.0
         with:
           version: v0.13.1
       - name: "Test ruff_wasm"
@@ -369,10 +267,10 @@ jobs:
     if: ${{ github.ref == 'refs/heads/main' }}
     timeout-minutes: 20
     steps:
-      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4
+      - uses: actions/checkout@v4
         with:
           persist-credentials: false
-      - uses: Swatinem/rust-cache@9d47c6ad4b02e050fd481d890b2ea34778fd09d6 # v2
+      - uses: Swatinem/rust-cache@v2
       - name: "Install Rust toolchain"
         run: rustup show
       - name: "Install mold"
@@ -387,15 +285,15 @@ jobs:
     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
+      - uses: actions/checkout@v4
         with:
           persist-credentials: false
-      - uses: SebRollen/toml-action@b1b3628f55fc3a28208d4203ada8b737e9687876 # v1.2.0
+      - uses: SebRollen/toml-action@v1.2.0
         id: msrv
         with:
           file: "Cargo.toml"
           field: "workspace.package.rust-version"
-      - uses: Swatinem/rust-cache@9d47c6ad4b02e050fd481d890b2ea34778fd09d6 # v2
+      - uses: Swatinem/rust-cache@v2
       - name: "Install Rust toolchain"
         env:
           MSRV: ${{ steps.msrv.outputs.value }}
@@ -403,11 +301,11 @@ jobs:
       - name: "Install mold"
         uses: rui314/setup-mold@v1
       - name: "Install cargo nextest"
-        uses: taiki-e/install-action@6aca1cfa12ef3a6b98ee8c70e0171bfa067604f5 # v2
+        uses: taiki-e/install-action@v2
         with:
           tool: cargo-nextest
       - name: "Install cargo insta"
-        uses: taiki-e/install-action@6aca1cfa12ef3a6b98ee8c70e0171bfa067604f5 # v2
+        uses: taiki-e/install-action@v2
         with:
           tool: cargo-insta
       - name: "Run tests"
@@ -424,10 +322,10 @@ jobs:
     if: ${{ github.ref == 'refs/heads/main' || needs.determine_changes.outputs.fuzz == 'true' || needs.determine_changes.outputs.code == 'true' }}
     timeout-minutes: 10
     steps:
-      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4
+      - uses: actions/checkout@v4
         with:
           persist-credentials: false
-      - uses: Swatinem/rust-cache@9d47c6ad4b02e050fd481d890b2ea34778fd09d6 # v2
+      - uses: Swatinem/rust-cache@v2
         with:
           workspaces: "fuzz -> target"
       - name: "Install Rust toolchain"
@@ -452,11 +350,11 @@ jobs:
     env:
       FORCE_COLOR: 1
     steps:
-      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4
+      - uses: actions/checkout@v4
         with:
           persist-credentials: false
-      - uses: astral-sh/setup-uv@0c5e2b8115b80b4c7c5ddf6ffdd634974642d182 # v5
-      - uses: actions/download-artifact@95815c38cf2ff2164869cbab79da8d1f422bc89e # v4
+      - uses: astral-sh/setup-uv@v5
+      - uses: actions/download-artifact@v4
         name: Download Ruff binary to test
         id: download-cached-binary
         with:
@@ -486,10 +384,10 @@ jobs:
     if: ${{ !contains(github.event.pull_request.labels.*.name, 'no-test') && (needs.determine_changes.outputs.code == 'true' || github.ref == 'refs/heads/main') }}
     timeout-minutes: 5
     steps:
-      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4
+      - uses: actions/checkout@v4
         with:
           persist-credentials: false
-      - uses: Swatinem/rust-cache@9d47c6ad4b02e050fd481d890b2ea34778fd09d6 # v2
+      - uses: Swatinem/rust-cache@v2
       - name: "Install Rust toolchain"
         run: rustup component add rustfmt
       # Run all code generation scripts, and verify that the current output is
@@ -518,21 +416,21 @@ jobs:
     if: ${{ !contains(github.event.pull_request.labels.*.name, 'no-test') && github.event_name == 'pull_request' && needs.determine_changes.outputs.code == 'true' }}
     timeout-minutes: 20
     steps:
-      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4
+      - uses: actions/checkout@v4
         with:
           persist-credentials: false
-      - uses: actions/setup-python@8d9ed9ac5c53483de85588cdf95a591a75ab9f55 # v5
+      - uses: actions/setup-python@v5
         with:
           python-version: ${{ env.PYTHON_VERSION }}
 
-      - uses: actions/download-artifact@95815c38cf2ff2164869cbab79da8d1f422bc89e # v4
+      - 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@v8
         name: Download baseline Ruff binary
         with:
           name: ruff
@@ -620,13 +518,13 @@ jobs:
         run: |
           echo ${{ github.event.number }} > pr-number
 
-      - uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02 # v4
+      - uses: actions/upload-artifact@v4
         name: Upload PR Number
         with:
           name: pr-number
           path: pr-number
 
-      - uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02 # v4
+      - uses: actions/upload-artifact@v4
         name: Upload Results
         with:
           name: ecosystem-result
@@ -638,7 +536,7 @@ jobs:
     needs: determine_changes
     if: ${{ needs.determine_changes.outputs.code == 'true' || github.ref == 'refs/heads/main' }}
     steps:
-      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4
+      - uses: actions/checkout@v4
         with:
           persist-credentials: false
       - uses: cargo-bins/cargo-binstall@main
@@ -651,18 +549,18 @@ jobs:
     timeout-minutes: 20
     if: ${{ !contains(github.event.pull_request.labels.*.name, 'no-test') }}
     steps:
-      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4
+      - uses: actions/checkout@v4
         with:
           persist-credentials: false
-      - uses: actions/setup-python@8d9ed9ac5c53483de85588cdf95a591a75ab9f55 # v5
+      - uses: actions/setup-python@v5
         with:
           python-version: ${{ env.PYTHON_VERSION }}
           architecture: x64
-      - uses: Swatinem/rust-cache@9d47c6ad4b02e050fd481d890b2ea34778fd09d6 # v2
+      - uses: Swatinem/rust-cache@v2
       - name: "Prep README.md"
         run: python scripts/transform_readme.py --target pypi
       - name: "Build wheels"
-        uses: PyO3/maturin-action@22fe573c6ed0c03ab9b84e631cbfa49bddf6e20e # v1.47.3
+        uses: PyO3/maturin-action@v1
         with:
           args: --out dist
       - name: "Test wheel"
@@ -675,15 +573,22 @@ 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
+      - uses: actions/checkout@v4
         with:
           persist-credentials: false
-      - uses: astral-sh/setup-uv@0c5e2b8115b80b4c7c5ddf6ffdd634974642d182 # v5
+      - uses: actions/setup-python@v5
+        with:
+          python-version: ${{ env.PYTHON_VERSION }}
+      - uses: Swatinem/rust-cache@v2
+      - name: "Install Rust toolchain"
+        run: rustup show
+      - name: "Install pre-commit"
+        run: pip install pre-commit
       - name: "Cache pre-commit"
-        uses: actions/cache@5a3ec84eff668545956fd18022155c47e93e2684 # v4
+        uses: actions/cache@v4
         with:
           path: ~/.cache/pre-commit
           key: pre-commit-${{ hashFiles('.pre-commit-config.yaml') }}
@@ -692,7 +597,7 @@ jobs:
           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 | \
+          SKIP=cargo-fmt,clippy,dev-generate-all 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"
@@ -705,22 +610,22 @@ jobs:
     env:
       MKDOCS_INSIDERS_SSH_KEY_EXISTS: ${{ secrets.MKDOCS_INSIDERS_SSH_KEY != '' }}
     steps:
-      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4
+      - uses: actions/checkout@v4
         with:
           persist-credentials: false
-      - uses: actions/setup-python@8d9ed9ac5c53483de85588cdf95a591a75ab9f55 # v5
+      - uses: actions/setup-python@v5
         with:
           python-version: "3.13"
-      - uses: Swatinem/rust-cache@9d47c6ad4b02e050fd481d890b2ea34778fd09d6 # v2
+      - uses: Swatinem/rust-cache@v2
       - 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
+        uses: astral-sh/setup-uv@v5
       - name: "Install Insiders dependencies"
         if: ${{ env.MKDOCS_INSIDERS_SSH_KEY_EXISTS == 'true' }}
         run: uv pip install -r docs/requirements-insiders.txt --system
@@ -747,10 +652,10 @@ jobs:
     if: ${{ !contains(github.event.pull_request.labels.*.name, 'no-test') && (needs.determine_changes.outputs.formatter == 'true' || github.ref == 'refs/heads/main') }}
     timeout-minutes: 10
     steps:
-      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4
+      - uses: actions/checkout@v4
         with:
           persist-credentials: false
-      - uses: Swatinem/rust-cache@9d47c6ad4b02e050fd481d890b2ea34778fd09d6 # v2
+      - uses: Swatinem/rust-cache@v2
       - name: "Install Rust toolchain"
         run: rustup show
       - name: "Run checks"
@@ -769,22 +674,21 @@ jobs:
       - determine_changes
     if: ${{ !contains(github.event.pull_request.labels.*.name, 'no-test') && (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
+      - uses: actions/checkout@v4
         name: "Download ruff-lsp source"
         with:
           persist-credentials: false
           repository: "astral-sh/ruff-lsp"
 
-      - uses: actions/setup-python@8d9ed9ac5c53483de85588cdf95a591a75ab9f55 # v5
+      - 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
+      - uses: actions/download-artifact@v4
         name: Download development ruff binary
         id: ruff-target
         with:
@@ -807,39 +711,6 @@ jobs:
 
           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
-        with:
-          persist-credentials: false
-      - name: "Install Rust toolchain"
-        run: rustup target add wasm32-unknown-unknown
-      - uses: Swatinem/rust-cache@9d47c6ad4b02e050fd481d890b2ea34778fd09d6 # v2
-      - uses: actions/setup-node@cdca7365b2dadb8aad0a33bc7601856ffabcc48e # v4
-        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
     needs: determine_changes
@@ -847,17 +718,17 @@ jobs:
     timeout-minutes: 20
     steps:
       - name: "Checkout Branch"
-        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4
+        uses: actions/checkout@v4
         with:
           persist-credentials: false
 
-      - uses: Swatinem/rust-cache@9d47c6ad4b02e050fd481d890b2ea34778fd09d6 # v2
+      - uses: Swatinem/rust-cache@v2
 
       - name: "Install Rust toolchain"
         run: rustup show
 
       - name: "Install codspeed"
-        uses: taiki-e/install-action@6aca1cfa12ef3a6b98ee8c70e0171bfa067604f5 # v2
+        uses: taiki-e/install-action@v2
         with:
           tool: cargo-codspeed
 
@@ -865,7 +736,7 @@ jobs:
         run: cargo codspeed build --features codspeed -p ruff_benchmark
 
       - name: "Run benchmarks"
-        uses: CodSpeedHQ/action@0010eb0ca6e89b80c88e8edaaa07cfe5f3e6664d # v3.5.0
+        uses: CodSpeedHQ/action@v3
         with:
           run: cargo codspeed run
           token: ${{ secrets.CODSPEED_TOKEN }}

.github/workflows/daily_fuzz.yaml

@@ -31,15 +31,15 @@ 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
+      - uses: actions/checkout@v4
         with:
           persist-credentials: false
-      - uses: astral-sh/setup-uv@0c5e2b8115b80b4c7c5ddf6ffdd634974642d182 # v5
+      - uses: astral-sh/setup-uv@v5
       - name: "Install Rust toolchain"
         run: rustup show
       - name: "Install mold"
         uses: rui314/setup-mold@v1
-      - uses: Swatinem/rust-cache@9d47c6ad4b02e050fd481d890b2ea34778fd09d6 # v2
+      - 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
@@ -65,7 +65,7 @@ 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: |

.github/workflows/daily_property_tests.yaml

@@ -30,14 +30,14 @@ 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
+      - uses: actions/checkout@v4
         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
+      - uses: Swatinem/rust-cache@v2
       - 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.
@@ -47,7 +47,6 @@ jobs:
         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
 
@@ -59,7 +58,7 @@ 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: |

.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 }}-${{ github.event.pull_request.number || github.sha }}
-  cancel-in-progress: true
-
-env:
-  CARGO_INCREMENTAL: 0
-  CARGO_NET_RETRY: 10
-  CARGO_TERM_COLOR: always
-  RUSTUP_MAX_RETRIES: 10
-
-jobs:
-  mypy_primer:
-    name: Run mypy_primer
-    runs-on: depot-ubuntu-22.04-16
-    timeout-minutes: 20
-    steps:
-      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4
-        with:
-          path: ruff
-          fetch-depth: 0
-          persist-credentials: false
-
-      - name: Install the latest version of uv
-        uses: astral-sh/setup-uv@0c5e2b8115b80b4c7c5ddf6ffdd634974642d182 # v5
-
-      - uses: Swatinem/rust-cache@9d47c6ad4b02e050fd481d890b2ea34778fd09d6 # v2
-        with:
-          workspaces: "ruff"
-      - name: Install Rust toolchain
-        run: rustup show
-
-      - name: Install mypy_primer
-        run: |
-          uv tool install "git+https://github.com/astral-sh/mypy_primer.git@add-red-knot-support-v2"
-
-      - name: Run mypy_primer
-        shell: bash
-        run: |
-          cd ruff
-
-          echo "new commit"
-          git rev-list --format=%s --max-count=1 "$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 "$GITHUB_SHA" \
-            --project-selector '/(mypy_primer|black|pyp|git-revise|zipp|arrow|isort|itsdangerous|rich|packaging|pybind11|pyinstrument|typeshed-stats|scrapy)$' \
-            --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
-        with:
-          name: mypy_primer_diff
-          path: mypy_primer.diff
-
-      - name: Upload pr-number
-        uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02 # v4
-        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

@@ -16,7 +16,7 @@ jobs:
     permissions:
       pull-requests: write
     steps:
-      - uses: dawidd6/action-download-artifact@20319c5641d495c8a52e688b7dc5fada6c3a9fbc # v8
+      - uses: dawidd6/action-download-artifact@v8
         name: Download pull request number
         with:
           name: pr-number
@@ -32,7 +32,7 @@ jobs:
             echo "pr-number=$(<pr-number)" >> "$GITHUB_OUTPUT"
           fi
 
-      - uses: dawidd6/action-download-artifact@20319c5641d495c8a52e688b7dc5fada6c3a9fbc # v8
+      - uses: dawidd6/action-download-artifact@v8
         name: "Download ecosystem results"
         id: download-ecosystem-result
         if: steps.pr-number.outputs.pr-number
@@ -70,7 +70,7 @@ jobs:
           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 +80,7 @@ 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

@@ -23,12 +23,12 @@ jobs:
     env:
       MKDOCS_INSIDERS_SSH_KEY_EXISTS: ${{ secrets.MKDOCS_INSIDERS_SSH_KEY != '' }}
     steps:
-      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4
+      - uses: actions/checkout@v4
         with:
           ref: ${{ inputs.ref }}
           persist-credentials: true
 
-      - uses: actions/setup-python@8d9ed9ac5c53483de85588cdf95a591a75ab9f55 # v5
+      - uses: actions/setup-python@v5
         with:
           python-version: 3.12
 
@@ -61,14 +61,14 @@ jobs:
 
       - 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
+      - uses: Swatinem/rust-cache@v2
 
       - name: "Install Insiders dependencies"
         if: ${{ env.MKDOCS_INSIDERS_SSH_KEY_EXISTS == 'true' }}

.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
-        with:
-          persist-credentials: false
-      - name: "Install Rust toolchain"
-        run: rustup target add wasm32-unknown-unknown
-      - uses: actions/setup-node@cdca7365b2dadb8aad0a33bc7601856ffabcc48e # v4
-        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 +24,36 @@ jobs:
     env:
       CF_API_TOKEN_EXISTS: ${{ secrets.CF_API_TOKEN != '' }}
     steps:
-      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4
+      - uses: actions/checkout@v4
         with:
           persist-credentials: false
       - name: "Install Rust toolchain"
         run: rustup target add wasm32-unknown-unknown
-      - uses: actions/setup-node@cdca7365b2dadb8aad0a33bc7601856ffabcc48e # v4
+      - uses: actions/setup-node@v4
         with:
-          node-version: 22
+          node-version: 20
           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
+        with:
+          version: v0.13.1
+      - 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@v3.14.0
         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

@@ -22,8 +22,8 @@ jobs:
       id-token: write
     steps:
       - name: "Install uv"
-        uses: astral-sh/setup-uv@0c5e2b8115b80b4c7c5ddf6ffdd634974642d182 # v5
-      - uses: actions/download-artifact@95815c38cf2ff2164869cbab79da8d1f422bc89e # v4
+        uses: astral-sh/setup-uv@v5
+      - uses: actions/download-artifact@v4
         with:
           pattern: wheels-*
           path: wheels

.github/workflows/publish-wasm.yml

@@ -29,15 +29,15 @@ jobs:
         target: [web, bundler, nodejs]
       fail-fast: false
     steps:
-      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4
+      - uses: actions/checkout@v4
         with:
           persist-credentials: false
       - name: "Install Rust toolchain"
         run: rustup target add wasm32-unknown-unknown
-      - uses: jetli/wasm-pack-action@0d096b08b4e5a7de8c28de67e11e945404e9eefa # v0.4.0
+      - uses: jetli/wasm-pack-action@v0.4.0
         with:
           version: v0.13.1
-      - uses: jetli/wasm-bindgen-action@20b33e20595891ab1a0ed73145d8a21fc96e7c29 # v0.2.0
+      - uses: jetli/wasm-bindgen-action@v0.2.0
       - name: "Run wasm-pack build"
         run: wasm-pack build --target ${{ matrix.target }} crates/ruff_wasm
       - name: "Rename generated package"
@@ -45,7 +45,7 @@ jobs:
           jq '.name="@astral-sh/ruff-wasm-${{ 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
+      - uses: actions/setup-node@v4
         with:
           node-version: 20
           registry-url: "https://registry.npmjs.org"

.github/workflows/release.yml

@@ -50,7 +50,7 @@ on:
 jobs:
   # Run '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) || '' }}
@@ -59,7 +59,7 @@ jobs:
     env:
       GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
     steps:
-      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4
+      - uses: actions/checkout@v4
         with:
           submodules: recursive
       - name: Install dist
@@ -68,7 +68,7 @@ jobs:
         shell: bash
         run: "curl --proto '=https' --tlsv1.2 -LsSf https://github.com/axodotdev/cargo-dist/releases/download/v0.25.2-prerelease.3/cargo-dist-installer.sh | sh"
       - name: Cache dist
-        uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02 # v4
+        uses: actions/upload-artifact@v4
         with:
           name: cargo-dist-cache
           path: ~/.cargo/bin/dist
@@ -84,7 +84,7 @@ jobs:
           cat plan-dist-manifest.json
           echo "manifest=$(jq -c "." plan-dist-manifest.json)" >> "$GITHUB_OUTPUT"
       - name: "Upload dist-manifest.json"
-        uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02 # v4
+        uses: actions/upload-artifact@v4
         with:
           name: artifacts-plan-dist-manifest
           path: plan-dist-manifest.json
@@ -116,23 +116,23 @@ 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 # v4
+      - uses: actions/checkout@v4
         with:
           submodules: recursive
       - name: Install cached dist
-        uses: actions/download-artifact@95815c38cf2ff2164869cbab79da8d1f422bc89e # v4
+        uses: actions/download-artifact@v4
         with:
           name: cargo-dist-cache
           path: ~/.cargo/bin/
       - run: chmod +x ~/.cargo/bin/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 # v4
+        uses: actions/download-artifact@v4
         with:
           pattern: artifacts-*
           path: target/distrib/
@@ -150,7 +150,7 @@ jobs:
 
           cp dist-manifest.json "$BUILD_MANIFEST_NAME"
       - name: "Upload artifacts"
-        uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02 # v4
+        uses: actions/upload-artifact@v4
         with:
           name: artifacts-build-global
           path: |
@@ -167,22 +167,22 @@ 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: ${{ steps.host.outputs.manifest }}
     steps:
-      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4
+      - uses: actions/checkout@v4
         with:
           submodules: recursive
       - name: Install cached dist
-        uses: actions/download-artifact@95815c38cf2ff2164869cbab79da8d1f422bc89e # v4
+        uses: actions/download-artifact@v4
         with:
           name: cargo-dist-cache
           path: ~/.cargo/bin/
       - run: chmod +x ~/.cargo/bin/dist
       # Fetch artifacts from scratch-storage
       - name: Fetch artifacts
-        uses: actions/download-artifact@95815c38cf2ff2164869cbab79da8d1f422bc89e # v4
+        uses: actions/download-artifact@v4
         with:
           pattern: artifacts-*
           path: target/distrib/
@@ -196,7 +196,7 @@ jobs:
           cat dist-manifest.json
           echo "manifest=$(jq -c "." dist-manifest.json)" >> "$GITHUB_OUTPUT"
       - name: "Upload dist-manifest.json"
-        uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02 # v4
+        uses: actions/upload-artifact@v4
         with:
           # Overwrite the previous copy
           name: artifacts-dist-manifest
@@ -242,16 +242,16 @@ jobs:
     # 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"
+    runs-on: "ubuntu-20.04"
     env:
       GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
     steps:
-      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4
+      - uses: actions/checkout@v4
         with:
           submodules: recursive
       # Create a GitHub Release while uploading all files to it
       - name: "Download GitHub Artifacts"
-        uses: actions/download-artifact@95815c38cf2ff2164869cbab79da8d1f422bc89e # v4
+        uses: actions/download-artifact@v4
         with:
           pattern: artifacts-*
           path: artifacts

.github/workflows/sync_typeshed.yaml

@@ -21,12 +21,12 @@ jobs:
       contents: write
       pull-requests: write
     steps:
-      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4
+      - uses: actions/checkout@v4
         name: Checkout Ruff
         with:
           path: ruff
           persist-credentials: true
-      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4
+      - uses: actions/checkout@v4
         name: Checkout typeshed
         with:
           repository: python/typeshed
@@ -70,7 +70,7 @@ 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: |

.ignore

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

.pre-commit-config.yaml

@@ -19,7 +19,7 @@ exclude: |
 
 repos:
   - repo: https://github.com/abravalheri/validate-pyproject
-    rev: v0.24.1
+    rev: v0.23
     hooks:
       - id: validate-pyproject
 
@@ -60,7 +60,7 @@ repos:
           - black==25.1.0
 
   - repo: https://github.com/crate-ci/typos
-    rev: v1.31.0
+    rev: v1.29.7
     hooks:
       - id: typos
 
@@ -74,7 +74,7 @@ repos:
         pass_filenames: false # This makes it a lot faster
 
   - repo: https://github.com/astral-sh/ruff-pre-commit
-    rev: v0.11.2
+    rev: v0.9.6
     hooks:
       - id: ruff-format
       - id: ruff
@@ -84,7 +84,7 @@ repos:
 
   # Prettier
   - repo: https://github.com/rbubley/mirrors-prettier
-    rev: v3.5.3
+    rev: v3.5.1
     hooks:
       - id: prettier
         types: [yaml]
@@ -92,12 +92,12 @@ repos:
   # 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
+    rev: v1.3.1
     hooks:
       - id: zizmor
 
   - repo: https://github.com/python-jsonschema/check-jsonschema
-    rev: 0.32.1
+    rev: 0.31.1
     hooks:
       - id: check-github-workflows
 

BREAKING_CHANGES.md

@@ -1,55 +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.

CHANGELOG.md

@@ -1,293 +1,5 @@
 # Changelog
 
-## 0.11.3
-
-### Preview features
-
-- \[`airflow`\] Add more autofixes for `AIR302` ([#16876](https://github.com/astral-sh/ruff/pull/16876), [#16977](https://github.com/astral-sh/ruff/pull/16977), [#16976](https://github.com/astral-sh/ruff/pull/16976), [#16965](https://github.com/astral-sh/ruff/pull/16965))
-- \[`airflow`\] Move `AIR301` to `AIR002` ([#16978](https://github.com/astral-sh/ruff/pull/16978))
-- \[`airflow`\] Move `AIR302` to `AIR301` and `AIR303` to `AIR302` ([#17151](https://github.com/astral-sh/ruff/pull/17151))
-- \[`flake8-bandit`\] Mark `str` and `list[str]` literals as trusted input (`S603`) ([#17136](https://github.com/astral-sh/ruff/pull/17136))
-- \[`ruff`\] Support slices in `RUF005` ([#17078](https://github.com/astral-sh/ruff/pull/17078))
-- [syntax-errors] Start detecting compile-time syntax errors ([#16106](https://github.com/astral-sh/ruff/pull/16106))
-- [syntax-errors] Duplicate type parameter names ([#16858](https://github.com/astral-sh/ruff/pull/16858))
-- [syntax-errors] Irrefutable `case` pattern before final case ([#16905](https://github.com/astral-sh/ruff/pull/16905))
-- [syntax-errors] Multiple assignments in `case` pattern ([#16957](https://github.com/astral-sh/ruff/pull/16957))
-- [syntax-errors] Single starred assignment target ([#17024](https://github.com/astral-sh/ruff/pull/17024))
-- [syntax-errors] Starred expressions in `return`, `yield`, and `for` ([#17134](https://github.com/astral-sh/ruff/pull/17134))
-- [syntax-errors] Store to or delete `__debug__` ([#16984](https://github.com/astral-sh/ruff/pull/16984))
-
-### Bug fixes
-
-- Error instead of `panic!` when running Ruff from a deleted directory (#16903) ([#17054](https://github.com/astral-sh/ruff/pull/17054))
-- [syntax-errors] Fix false positive for parenthesized tuple index ([#16948](https://github.com/astral-sh/ruff/pull/16948))
-
-### CLI
-
-- Check `pyproject.toml` correctly when it is passed via stdin ([#16971](https://github.com/astral-sh/ruff/pull/16971))
-
-### Configuration
-
-- \[`flake8-import-conventions`\] Add import `numpy.typing as npt` to default `flake8-import-conventions.aliases` ([#17133](https://github.com/astral-sh/ruff/pull/17133))
-
-### Documentation
-
-- \[`refurb`\] Document why `UserDict`, `UserList`, and `UserString` are preferred over `dict`, `list`, and `str` (`FURB189`) ([#16927](https://github.com/astral-sh/ruff/pull/16927))
-
-## 0.11.2
-
-### Preview features
-
-- [syntax-errors] Fix false-positive syntax errors emitted for annotations on variadic parameters before Python 3.11 ([#16878](https://github.com/astral-sh/ruff/pull/16878))
-
-## 0.11.1
-
-### Preview features
-
-- \[`airflow`\] Add `chain`, `chain_linear` and `cross_downstream` for `AIR302` ([#16647](https://github.com/astral-sh/ruff/pull/16647))
-- [syntax-errors] Improve error message and range for pre-PEP-614 decorator syntax errors ([#16581](https://github.com/astral-sh/ruff/pull/16581))
-- [syntax-errors] PEP 701 f-strings before Python 3.12 ([#16543](https://github.com/astral-sh/ruff/pull/16543))
-- [syntax-errors] Parenthesized context managers before Python 3.9 ([#16523](https://github.com/astral-sh/ruff/pull/16523))
-- [syntax-errors] Star annotations before Python 3.11 ([#16545](https://github.com/astral-sh/ruff/pull/16545))
-- [syntax-errors] Star expression in index before Python 3.11 ([#16544](https://github.com/astral-sh/ruff/pull/16544))
-- [syntax-errors] Unparenthesized assignment expressions in sets and indexes ([#16404](https://github.com/astral-sh/ruff/pull/16404))
-
-### Bug fixes
-
-- Server: Allow `FixAll` action in presence of version-specific syntax errors ([#16848](https://github.com/astral-sh/ruff/pull/16848))
-- \[`flake8-bandit`\] Allow raw strings in `suspicious-mark-safe-usage` (`S308`) #16702 ([#16770](https://github.com/astral-sh/ruff/pull/16770))
-- \[`refurb`\] Avoid panicking `unwrap` in `verbose-decimal-constructor` (`FURB157`) ([#16777](https://github.com/astral-sh/ruff/pull/16777))
-- \[`refurb`\] Fix starred expressions fix (`FURB161`) ([#16550](https://github.com/astral-sh/ruff/pull/16550))
-- Fix `--statistics` reporting for unsafe fixes ([#16756](https://github.com/astral-sh/ruff/pull/16756))
-
-### Rule changes
-
-- \[`flake8-executables`\] Allow `uv run` in shebang line for `shebang-missing-python` (`EXE003`) ([#16849](https://github.com/astral-sh/ruff/pull/16849),[#16855](https://github.com/astral-sh/ruff/pull/16855))
-
-### CLI
-
-- Add `--exit-non-zero-on-format` ([#16009](https://github.com/astral-sh/ruff/pull/16009))
-
-### Documentation
-
-- Update Ruff tutorial to avoid non-existent fix in `__init__.py` ([#16818](https://github.com/astral-sh/ruff/pull/16818))
-- \[`flake8-gettext`\] Swap `format-` and `printf-in-get-text-func-call` examples (`INT002`, `INT003`) ([#16769](https://github.com/astral-sh/ruff/pull/16769))
-
-## 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`.
-
-### Breaking changes
-
-- **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.
-
-### Stabilization
-
-The following behaviors have been stabilized:
-
-- [`blanket-noqa`](https://docs.astral.sh/ruff/rules/blanket-noqa/) (`PGH004`): Also detect blanked file-level noqa comments (and not just line level comments).
-
-### Preview features
-
-- [syntax-errors] Tuple unpacking in `for` statement iterator clause before Python 3.9 ([#16558](https://github.com/astral-sh/ruff/pull/16558))
-
-## 0.10.0
-
-Check out the [blog post](https://astral.sh/blog/ruff-v0.10.0) for a migration guide and overview of the changes!
-
-### Breaking changes
-
-See also, the "Remapped rules" section which may result in disabled rules.
-
-- **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.
-
-### Deprecated Rules
-
-The following rules have been deprecated:
-
-- [`non-pep604-isinstance`](https://docs.astral.sh/ruff/rules/non-pep604-isinstance/) (`UP038`)
-- [`suspicious-xmle-tree-usage`](https://docs.astral.sh/ruff/rules/suspicious-xmle-tree-usage/) (`S320`)
-
-### Remapped rules
-
-The following rules have been remapped to new rule codes:
-
-- \[`unsafe-markup-use`\]: `RUF035` to `S704`
-
-### Stabilization
-
-The following rules have been stabilized and are no longer in preview:
-
-- [`batched-without-explicit-strict`](https://docs.astral.sh/ruff/rules/batched-without-explicit-strict) (`B911`)
-- [`unnecessary-dict-comprehension-for-iterable`](https://docs.astral.sh/ruff/rules/unnecessary-dict-comprehension-for-iterable) (`C420`)
-- [`datetime-min-max`](https://docs.astral.sh/ruff/rules/datetime-min-max) (`DTZ901`)
-- [`fast-api-unused-path-parameter`](https://docs.astral.sh/ruff/rules/fast-api-unused-path-parameter) (`FAST003`)
-- [`root-logger-call`](https://docs.astral.sh/ruff/rules/root-logger-call) (`LOG015`)
-- [`len-test`](https://docs.astral.sh/ruff/rules/len-test) (`PLC1802`)
-- [`shallow-copy-environ`](https://docs.astral.sh/ruff/rules/shallow-copy-environ) (`PLW1507`)
-- [`os-listdir`](https://docs.astral.sh/ruff/rules/os-listdir) (`PTH208`)
-- [`invalid-pathlib-with-suffix`](https://docs.astral.sh/ruff/rules/invalid-pathlib-with-suffix) (`PTH210`)
-- [`invalid-assert-message-literal-argument`](https://docs.astral.sh/ruff/rules/invalid-assert-message-literal-argument) (`RUF040`)
-- [`unnecessary-nested-literal`](https://docs.astral.sh/ruff/rules/unnecessary-nested-literal) (`RUF041`)
-- [`unnecessary-cast-to-int`](https://docs.astral.sh/ruff/rules/unnecessary-cast-to-int) (`RUF046`)
-- [`map-int-version-parsing`](https://docs.astral.sh/ruff/rules/map-int-version-parsing) (`RUF048`)
-- [`if-key-in-dict-del`](https://docs.astral.sh/ruff/rules/if-key-in-dict-del) (`RUF051`)
-- [`unsafe-markup-use`](https://docs.astral.sh/ruff/rules/unsafe-markup-use) (`S704`). This rule has also been renamed from `RUF035`.
-- [`split-static-string`](https://docs.astral.sh/ruff/rules/split-static-string) (`SIM905`)
-- [`runtime-cast-value`](https://docs.astral.sh/ruff/rules/runtime-cast-value) (`TC006`)
-- [`unquoted-type-alias`](https://docs.astral.sh/ruff/rules/unquoted-type-alias) (`TC007`)
-- [`non-pep646-unpack`](https://docs.astral.sh/ruff/rules/non-pep646-unpack) (`UP044`)
-
-The following behaviors have been stabilized:
-
-- [`bad-staticmethod-argument`](https://docs.astral.sh/ruff/rules/bad-staticmethod-argument/) (`PLW0211`) [`invalid-first-argument-name-for-class-method`](https://docs.astral.sh/ruff/rules/invalid-first-argument-name-for-class-method/) (`N804`): `__new__` methods are now no longer flagged by `invalid-first-argument-name-for-class-method` (`N804`) but instead by `bad-staticmethod-argument` (`PLW0211`)
-- [`bad-str-strip-call`](https://docs.astral.sh/ruff/rules/bad-str-strip-call/) (`PLE1310`): The rule now applies to objects which are known to have type `str` or `bytes`.
-- [`custom-type-var-for-self`](https://docs.astral.sh/ruff/rules/custom-type-var-for-self/) (`PYI019`): More accurate detection of custom `TypeVars` replaceable by `Self`. The range of the diagnostic is now the full function header rather than just the return annotation.
-- [`invalid-argument-name`](https://docs.astral.sh/ruff/rules/invalid-argument-name/) (`N803`): Ignore argument names of functions decorated with `typing.override`
-- [`invalid-envvar-default`](https://docs.astral.sh/ruff/rules/invalid-envvar-default/) (`PLW1508`): Detect default value arguments to `os.environ.get` with invalid type.
-- [`pytest-raises-with-multiple-statements`](https://docs.astral.sh/ruff/rules/pytest-raises-with-multiple-statements/) (`PT012`) [`pytest-warns-with-multiple-statements`](https://docs.astral.sh/ruff/rules/pytest-warns-with-multiple-statements/) (`PT031`): Allow `for` statements with an empty body in `pytest.raises` and `pytest.warns` `with` statements.
-- [`redundant-open-modes`](https://docs.astral.sh/ruff/rules/redundant-open-modes/) (`UP015`): The diagnostic range is now the range of the redundant mode argument where it previously was the range of the entire open call. You may have to replace your `noqa` comments when suppressing `UP015`.
-- [`stdlib-module-shadowing`](https://docs.astral.sh/ruff/rules/stdlib-module-shadowing/) (`A005`): Changes the default value of `lint.flake8-builtins.strict-checking` from `true` to `false`.
-- [`type-none-comparison`](https://docs.astral.sh/ruff/rules/type-none-comparison/) (`FURB169`): Now also recognizes `type(expr) is type(None)` comparisons where `expr` isn't a name expression.
-
-The following fixes or improvements to fixes have been stabilized:
-
-- [`repeated-equality-comparison`](https://docs.astral.sh/ruff/rules/repeated-equality-comparison/) (`PLR1714`) ([#16685](https://github.com/astral-sh/ruff/pull/16685))
-- [`needless-bool`](https://docs.astral.sh/ruff/rules/needless-bool/) (`SIM103`) ([#16684](https://github.com/astral-sh/ruff/pull/16684))
-- [`unused-private-type-var`](https://docs.astral.sh/ruff/rules/unused-private-type-var/) (`PYI018`) ([#16682](https://github.com/astral-sh/ruff/pull/16682))
-
-### Server
-
-- Remove logging output for `ruff.printDebugInformation` ([#16617](https://github.com/astral-sh/ruff/pull/16617))
-
-### Configuration
-
-- \[`flake8-builtins`\] Deprecate the `builtins-` prefixed options in favor of the unprefixed options (e.g. `builtins-allowed-modules` is now deprecated in favor of `allowed-modules`) ([#16092](https://github.com/astral-sh/ruff/pull/16092))
-
-### Bug fixes
-
-- [flake8-bandit] Fix mixed-case hash algorithm names (S324) ([#16552](https://github.com/astral-sh/ruff/pull/16552))
-
-### CLI
-
-- [ruff] Fix `last_tag`/`commits_since_last_tag` for `version` command ([#16686](https://github.com/astral-sh/ruff/pull/16686))
-
-## 0.9.10
-
-### Preview features
-
-- \[`ruff`\] Add new rule `RUF059`: Unused unpacked assignment ([#16449](https://github.com/astral-sh/ruff/pull/16449))
-- \[`syntax-errors`\] Detect assignment expressions before Python 3.8 ([#16383](https://github.com/astral-sh/ruff/pull/16383))
-- \[`syntax-errors`\] Named expressions in decorators before Python 3.9 ([#16386](https://github.com/astral-sh/ruff/pull/16386))
-- \[`syntax-errors`\] Parenthesized keyword argument names after Python 3.8 ([#16482](https://github.com/astral-sh/ruff/pull/16482))
-- \[`syntax-errors`\] Positional-only parameters before Python 3.8 ([#16481](https://github.com/astral-sh/ruff/pull/16481))
-- \[`syntax-errors`\] Tuple unpacking in `return` and `yield` before Python 3.8 ([#16485](https://github.com/astral-sh/ruff/pull/16485))
-- \[`syntax-errors`\] Type parameter defaults before Python 3.13 ([#16447](https://github.com/astral-sh/ruff/pull/16447))
-- \[`syntax-errors`\] Type parameter lists before Python 3.12 ([#16479](https://github.com/astral-sh/ruff/pull/16479))
-- \[`syntax-errors`\] `except*` before Python 3.11 ([#16446](https://github.com/astral-sh/ruff/pull/16446))
-- \[`syntax-errors`\] `type` statements before Python 3.12 ([#16478](https://github.com/astral-sh/ruff/pull/16478))
-
-### Bug fixes
-
-- Escape template filenames in glob patterns in configuration ([#16407](https://github.com/astral-sh/ruff/pull/16407))
-- \[`flake8-simplify`\] Exempt unittest context methods for `SIM115` rule ([#16439](https://github.com/astral-sh/ruff/pull/16439))
-- Formatter: Fix syntax error location in notebooks ([#16499](https://github.com/astral-sh/ruff/pull/16499))
-- \[`pyupgrade`\] Do not offer fix when at least one target is `global`/`nonlocal` (`UP028`) ([#16451](https://github.com/astral-sh/ruff/pull/16451))
-- \[`flake8-builtins`\] Ignore variables matching module attribute names (`A001`) ([#16454](https://github.com/astral-sh/ruff/pull/16454))
-- \[`pylint`\] Convert `code` keyword argument to a positional argument in fix for (`PLR1722`) ([#16424](https://github.com/astral-sh/ruff/pull/16424))
-
-### CLI
-
-- Move rule code from `description` to `check_name` in GitLab output serializer ([#16437](https://github.com/astral-sh/ruff/pull/16437))
-
-### Documentation
-
-- \[`pydocstyle`\] Clarify that `D417` only checks docstrings with an arguments section ([#16494](https://github.com/astral-sh/ruff/pull/16494))
-
-## 0.9.9
-
-### Preview features
-
-- Fix caching of unsupported-syntax errors ([#16425](https://github.com/astral-sh/ruff/pull/16425))
-
-### Bug fixes
-
-- Only show unsupported-syntax errors in editors when preview mode is enabled ([#16429](https://github.com/astral-sh/ruff/pull/16429))
-
-## 0.9.8
-
-### Preview features
-
-- Start detecting version-related syntax errors in the parser ([#16090](https://github.com/astral-sh/ruff/pull/16090))
-
-### Rule changes
-
-- \[`pylint`\] Mark fix unsafe (`PLW1507`) ([#16343](https://github.com/astral-sh/ruff/pull/16343))
-- \[`pylint`\] Catch `case np.nan`/`case math.nan` in `match` statements (`PLW0177`) ([#16378](https://github.com/astral-sh/ruff/pull/16378))
-- \[`ruff`\] Add more Pydantic models variants to the list of default copy semantics (`RUF012`) ([#16291](https://github.com/astral-sh/ruff/pull/16291))
-
-### Server
-
-- Avoid indexing the project if `configurationPreference` is `editorOnly` ([#16381](https://github.com/astral-sh/ruff/pull/16381))
-- Avoid unnecessary info at non-trace server log level ([#16389](https://github.com/astral-sh/ruff/pull/16389))
-- Expand `ruff.configuration` to allow inline config ([#16296](https://github.com/astral-sh/ruff/pull/16296))
-- Notify users for invalid client settings ([#16361](https://github.com/astral-sh/ruff/pull/16361))
-
-### Configuration
-
-- Add `per-file-target-version` option ([#16257](https://github.com/astral-sh/ruff/pull/16257))
-
-### Bug fixes
-
-- \[`refurb`\] Do not consider docstring(s) (`FURB156`) ([#16391](https://github.com/astral-sh/ruff/pull/16391))
-- \[`flake8-self`\] Ignore attribute accesses on instance-like variables (`SLF001`) ([#16149](https://github.com/astral-sh/ruff/pull/16149))
-- \[`pylint`\] Fix false positives, add missing methods, and support positional-only parameters (`PLE0302`) ([#16263](https://github.com/astral-sh/ruff/pull/16263))
-- \[`flake8-pyi`\] Mark `PYI030` fix unsafe when comments are deleted ([#16322](https://github.com/astral-sh/ruff/pull/16322))
-
-### Documentation
-
-- Fix example for `S611` ([#16316](https://github.com/astral-sh/ruff/pull/16316))
-- Normalize inconsistent markdown headings in docstrings ([#16364](https://github.com/astral-sh/ruff/pull/16364))
-- Document MSRV policy ([#16384](https://github.com/astral-sh/ruff/pull/16384))
-
 ## 0.9.7
 
 ### Preview features
@@ -301,7 +13,16 @@ The following fixes or improvements to fixes have been stabilized:
 
 ### Rule changes
 
+- \[`flake8-comprehensions`\]: Handle trailing comma in `C403` fix ([#16110](https://github.com/astral-sh/ruff/pull/16110))
 - \[`flake8-debugger`\] Also flag `sys.breakpointhook` and `sys.__breakpointhook__` (`T100`) ([#16191](https://github.com/astral-sh/ruff/pull/16191))
+- \[`pydocstyle`\] Handle arguments with the same names as sections (`D417`) ([#16011](https://github.com/astral-sh/ruff/pull/16011))
+- \[`pylint`\] Correct ordering of arguments in fix for `if-stmt-min-max` (`PLR1730`) ([#16080](https://github.com/astral-sh/ruff/pull/16080))
+- \[`pylint`\] Do not offer fix for raw strings (`PLE251`) ([#16132](https://github.com/astral-sh/ruff/pull/16132))
+- \[`pyupgrade`\] Do not upgrade functional `TypedDicts` with private field names to the class-based syntax (`UP013`) ([#16219](https://github.com/astral-sh/ruff/pull/16219))
+- \[`pyupgrade`\] Handle micro version numbers correctly (`UP036`) ([#16091](https://github.com/astral-sh/ruff/pull/16091))
+- \[`pyupgrade`\] Unwrap unary expressions correctly (`UP018`) ([#15919](https://github.com/astral-sh/ruff/pull/15919))
+- \[`ruff`\] Skip `RUF001` diagnostics when visiting string type definitions ([#16122](https://github.com/astral-sh/ruff/pull/16122))
+- \[`flake8-pyi`\] Avoid flagging `custom-typevar-for-self` on metaclass methods (`PYI019`) ([#16141](https://github.com/astral-sh/ruff/pull/16141))
 - \[`pycodestyle`\] Exempt `site.addsitedir(...)` calls (`E402`) ([#16251](https://github.com/astral-sh/ruff/pull/16251))
 
 ### Formatter
@@ -322,16 +43,7 @@ The following fixes or improvements to fixes have been stabilized:
 
 ### Bug fixes
 
-- \[`flake8-comprehensions`\] Handle trailing comma in `C403` fix ([#16110](https://github.com/astral-sh/ruff/pull/16110))
-- \[`flake8-pyi`\] Avoid flagging `custom-typevar-for-self` on metaclass methods (`PYI019`) ([#16141](https://github.com/astral-sh/ruff/pull/16141))
-- \[`pydocstyle`\] Handle arguments with the same names as sections (`D417`) ([#16011](https://github.com/astral-sh/ruff/pull/16011))
-- \[`pylint`\] Correct ordering of arguments in fix for `if-stmt-min-max` (`PLR1730`) ([#16080](https://github.com/astral-sh/ruff/pull/16080))
-- \[`pylint`\] Do not offer fix for raw strings (`PLE251`) ([#16132](https://github.com/astral-sh/ruff/pull/16132))
-- \[`pyupgrade`\] Do not upgrade functional `TypedDicts` with private field names to the class-based syntax (`UP013`) ([#16219](https://github.com/astral-sh/ruff/pull/16219))
-- \[`pyupgrade`\] Handle micro version numbers correctly (`UP036`) ([#16091](https://github.com/astral-sh/ruff/pull/16091))
-- \[`pyupgrade`\] Unwrap unary expressions correctly (`UP018`) ([#15919](https://github.com/astral-sh/ruff/pull/15919))
 - \[`refurb`\] Correctly handle lengths of literal strings in `slice-to-remove-prefix-or-suffix` (`FURB188`) ([#16237](https://github.com/astral-sh/ruff/pull/16237))
-- \[`ruff`\] Skip `RUF001` diagnostics when visiting string type definitions ([#16122](https://github.com/astral-sh/ruff/pull/16122))
 
 ### Documentation
 
@@ -1455,11 +1167,11 @@ The following rules have been stabilized and are no longer in preview:
 
 The following behaviors have been stabilized:
 
-- [`cancel-scope-no-checkpoint`](https://docs.astral.sh/ruff/rules/cancel-scope-no-checkpoint/) (`ASYNC100`): Support `asyncio` and `anyio` context managers.
-- [`async-function-with-timeout`](https://docs.astral.sh/ruff/rules/async-function-with-timeout/) (`ASYNC109`): Support `asyncio` and `anyio` context managers.
-- [`async-busy-wait`](https://docs.astral.sh/ruff/rules/async-busy-wait/) (`ASYNC110`): Support `asyncio` and `anyio` context managers.
-- [`async-zero-sleep`](https://docs.astral.sh/ruff/rules/async-zero-sleep/) (`ASYNC115`): Support `anyio` context managers.
-- [`long-sleep-not-forever`](https://docs.astral.sh/ruff/rules/long-sleep-not-forever/) (`ASYNC116`): Support `anyio` context managers.
+- [`cancel-scope-no-checkpoint`](https://docs.astral.sh/ruff/rules/cancel-scope-no-checkpoint/) (`ASYNC100`): Support `asyncio` and `anyio` context mangers.
+- [`async-function-with-timeout`](https://docs.astral.sh/ruff/rules/async-function-with-timeout/) (`ASYNC109`): Support `asyncio` and `anyio` context mangers.
+- [`async-busy-wait`](https://docs.astral.sh/ruff/rules/async-busy-wait/) (`ASYNC110`): Support `asyncio` and `anyio` context mangers.
+- [`async-zero-sleep`](https://docs.astral.sh/ruff/rules/async-zero-sleep/) (`ASYNC115`): Support `anyio` context mangers.
+- [`long-sleep-not-forever`](https://docs.astral.sh/ruff/rules/long-sleep-not-forever/) (`ASYNC116`): Support `anyio` context mangers.
 
 The following fixes have been stabilized:
 

Cargo.toml

@@ -4,7 +4,7 @@ resolver = "2"
 
 [workspace.package]
 edition = "2021"
-rust-version = "1.83"
+rust-version = "1.80"
 homepage = "https://docs.astral.sh/ruff"
 documentation = "https://docs.astral.sh/ruff"
 repository = "https://github.com/astral-sh/ruff"
@@ -38,11 +38,10 @@ 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_python_semantic = { path = "crates/red_knot_python_semantic" }
 red_knot_server = { path = "crates/red_knot_server" }
 red_knot_test = { path = "crates/red_knot_test" }
+red_knot_project = { path = "crates/red_knot_project", default-features = false }
 
 aho-corasick = { version = "1.1.3" }
 anstream = { version = "0.6.18" }
@@ -64,7 +63,7 @@ colored = { version = "3.0.0" }
 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 = "0.8.0"
 criterion = { version = "0.5.1", default-features = false }
 crossbeam = { version = "0.8.4" }
 dashmap = { version = "6.0.1" }
@@ -72,7 +71,7 @@ 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" }
+etcetera = { version = "0.8.0" }
 fern = { version = "0.7.0" }
 filetime = { version = "0.2.23" }
 getrandom = { version = "0.3.1" }
@@ -124,7 +123,7 @@ 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 = "d758691ba17ee1a60c5356ea90888d529e1782ad" }
+salsa = { git = "https://github.com/salsa-rs/salsa.git", rev = "351d9cf0037be949d17800d0c7b4838e533c2ed6" }
 schemars = { version = "0.8.16" }
 seahash = { version = "4.1.0" }
 serde = { version = "1.0.197", features = ["derive"] }
@@ -155,7 +154,6 @@ 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",
@@ -328,9 +326,3 @@ github-custom-job-permissions = { "build-docker" = { packages = "write", content
 install-updater = false
 # Path that installers should place binaries in
 install-path = ["$XDG_BIN_HOME/", "$XDG_DATA_HOME/../bin", "~/.local/bin"]
-# Temporarily allow changes to the `release` workflow, in which we pin actions
-# to a SHA instead of a tag (https://github.com/astral-sh/uv/issues/12253)
-allow-dirty = ["ci"]
-
-[workspace.metadata.dist.github-custom-runners]
-global = "depot-ubuntu-latest-4"

README.md

@@ -149,8 +149,8 @@ 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/0.11.3/install.sh | sh
-powershell -c "irm https://astral.sh/ruff/0.11.3/install.ps1 | iex"
+curl -LsSf https://astral.sh/ruff/0.9.7/install.sh | sh
+powershell -c "irm https://astral.sh/ruff/0.9.7/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 +183,7 @@ 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: v0.11.3
+  rev: v0.9.7
   hooks:
     # Run the linter.
     - id: ruff

_typos.toml

@@ -23,10 +23,6 @@ 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",
 ]
 
 [default.extend-identifiers]

crates/red_knot/Cargo.toml

@@ -19,7 +19,6 @@ ruff_db = { workspace = true, features = ["os", "cache"] }
 ruff_python_ast = { workspace = true }
 
 anyhow = { workspace = true }
-argfile = { workspace = true }
 chrono = { workspace = true }
 clap = { workspace = true, features = ["wrap_help"] }
 colored = { workspace = true }
@@ -32,7 +31,6 @@ tracing = { workspace = true, features = ["release_max_level_debug"] }
 tracing-subscriber = { workspace = true, features = ["env-filter", "fmt"] }
 tracing-flame = { workspace = true }
 tracing-tree = { workspace = true }
-wild = { workspace = true }
 
 [dev-dependencies]
 ruff_db = { workspace = true, features = ["testing"] }

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/src/args.rs

@@ -32,13 +32,6 @@ pub(crate) enum Command {
 
 #[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,
@@ -48,16 +41,12 @@ pub(crate) struct CheckCommand {
     #[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.
+    /// Path to the virtual environment the project uses.
     ///
-    /// 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.
+    /// If provided, red-knot will use the `site-packages` directory of this virtual environment
+    /// to resolve type information for the project's third-party dependencies.
     #[arg(long, value_name = "PATH")]
-    pub(crate) python: Option<SystemPathBuf>,
+    pub(crate) venv_path: Option<SystemPathBuf>,
 
     /// Custom directory to use for stdlib typeshed stubs.
     #[arg(long, value_name = "PATH", alias = "custom-typeshed-dir")]
@@ -77,14 +66,6 @@ pub(crate) struct CheckCommand {
     #[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>,
@@ -93,7 +74,7 @@ pub(crate) struct CheckCommand {
     #[arg(long)]
     pub(crate) exit_zero: bool,
 
-    /// Watch files for changes and recheck files related to the changed files.
+    /// Run in watch mode by re-running whenever files change.
     #[arg(long, short = 'W')]
     pub(crate) watch: bool,
 }
@@ -116,7 +97,7 @@ impl CheckCommand {
                 python_version: self
                     .python_version
                     .map(|version| RangedValue::cli(version.into())),
-                python: self.python.map(RelativePathBuf::cli),
+                venv_path: self.venv_path.map(RelativePathBuf::cli),
                 typeshed: self.typeshed.map(RelativePathBuf::cli),
                 extra_paths: self.extra_search_path.map(|extra_search_paths| {
                     extra_search_paths
@@ -127,9 +108,6 @@ impl CheckCommand {
                 ..EnvironmentOptions::default()
             }),
             terminal: Some(TerminalOptions {
-                output_format: self
-                    .output_format
-                    .map(|output_format| RangedValue::cli(output_format.into())),
                 error_on_warning: self.error_on_warning,
             }),
             rules,
@@ -224,46 +202,3 @@ impl clap::Args for RulesArg {
         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/main.rs

@@ -1,10 +1,10 @@
-use std::io::{self, stdout, BufWriter, Write};
+use std::io::{self, BufWriter, Write};
 use std::process::{ExitCode, Termination};
 
 use anyhow::Result;
 use std::sync::Mutex;
 
-use crate::args::{Args, CheckCommand, Command, TerminalColor};
+use crate::args::{Args, CheckCommand, Command};
 use crate::logging::setup_tracing;
 use anyhow::{anyhow, Context};
 use clap::Parser;
@@ -16,7 +16,7 @@ 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 ruff_db::system::{OsSystem, System, SystemPath, SystemPathBuf};
 use salsa::plumbing::ZalsaDatabase;
 
 mod args;
@@ -39,15 +39,6 @@ pub fn main() -> ExitStatus {
         // 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();
         }
 
@@ -56,10 +47,7 @@ pub fn main() -> ExitStatus {
 }
 
 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);
+    let args = Args::parse_from(std::env::args());
 
     match args.command {
         Command::Server => run_server().map(|()| ExitStatus::Success),
@@ -76,16 +64,12 @@ pub(crate) fn version() -> Result<()> {
 }
 
 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 cli_base_path = {
         let cwd = std::env::current_dir().context("Failed to get the current working directory")?;
         SystemPathBuf::from_path_buf(cwd)
             .map_err(|path| {
@@ -96,42 +80,30 @@ fn run_check(args: CheckCommand) -> anyhow::Result<ExitStatus> {
             })?
     };
 
-    let project_path = args
+    let cwd = args
         .project
         .as_ref()
-        .map(|project| {
-            if project.as_std_path().is_dir() {
-                Ok(SystemPath::absolute(project, &cwd))
+        .map(|cwd| {
+            if cwd.as_std_path().is_dir() {
+                Ok(SystemPath::absolute(cwd, &cli_base_path))
             } else {
-                Err(anyhow!(
-                    "Provided project path `{project}` is not a directory"
-                ))
+                Err(anyhow!("Provided project path `{cwd}` is not a directory"))
             }
         })
         .transpose()?
-        .unwrap_or_else(|| cwd.clone());
-
-    let check_paths: Vec<_> = args
-        .paths
-        .iter()
-        .map(|path| SystemPath::absolute(path, &cwd))
-        .collect();
+        .unwrap_or_else(|| cli_base_path.clone());
 
     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)?;
+    let mut project_metadata = ProjectMetadata::discover(system.current_directory(), &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);
-    }
-
     let (main_loop, main_loop_cancellation_token) = MainLoop::new(cli_options);
 
     // Listen to Ctrl+C and abort the watch mode.
@@ -147,7 +119,7 @@ fn run_check(args: CheckCommand) -> anyhow::Result<ExitStatus> {
     let exit_status = if watch {
         main_loop.watch(&mut db)?
     } else {
-        main_loop.run(&mut db)?
+        main_loop.run(&mut db)
     };
 
     tracing::trace!("Counts for entire CLI run:\n{}", countme::get_all());
@@ -207,7 +179,7 @@ impl MainLoop {
         )
     }
 
-    fn watch(mut self, db: &mut ProjectDatabase) -> Result<ExitStatus> {
+    fn watch(mut self, db: &mut ProjectDatabase) -> anyhow::Result<ExitStatus> {
         tracing::debug!("Starting watch mode");
         let sender = self.sender.clone();
         let watcher = watch::directory_watcher(move |event| {
@@ -216,12 +188,12 @@ impl MainLoop {
 
         self.watcher = Some(ProjectWatcher::new(watcher, db));
 
-        self.run(db)?;
+        self.run(db);
 
         Ok(ExitStatus::Success)
     }
 
-    fn run(mut self, db: &mut ProjectDatabase) -> Result<ExitStatus> {
+    fn run(mut self, db: &mut ProjectDatabase) -> ExitStatus {
         self.sender.send(MainLoopMessage::CheckWorkspace).unwrap();
 
         let result = self.main_loop(db);
@@ -231,7 +203,7 @@ impl MainLoop {
         result
     }
 
-    fn main_loop(&mut self, db: &mut ProjectDatabase) -> Result<ExitStatus> {
+    fn main_loop(&mut self, db: &mut ProjectDatabase) -> ExitStatus {
         // Schedule the first check.
         tracing::debug!("Starting main loop");
 
@@ -259,54 +231,24 @@ impl MainLoop {
                     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
-                    };
+                    let min_error_severity =
+                        if db.project().settings(db).terminal().error_on_warning {
+                            Severity::Warning
+                        } else {
+                            Severity::Error
+                        };
+
+                    let failed = result
+                        .iter()
+                        .any(|diagnostic| diagnostic.severity() >= min_error_severity);
 
                     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
-                                });
-                            }
+                        #[allow(clippy::print_stdout)]
+                        for diagnostic in result {
+                            println!("{}", diagnostic.display(db, &display_config));
                         }
                     } else {
                         tracing::debug!(
@@ -314,6 +256,14 @@ impl MainLoop {
                         );
                     }
 
+                    if self.watcher.is_none() {
+                        return if failed {
+                            ExitStatus::Failure
+                        } else {
+                            ExitStatus::Success
+                        };
+                    }
+
                     tracing::trace!("Counts after last check:\n{}", countme::get_all());
                 }
 
@@ -331,14 +281,14 @@ impl MainLoop {
                     // 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);
+                    return ExitStatus::Success;
                 }
             }
 
             tracing::debug!("Waiting for next main loop message.");
         }
 
-        Ok(ExitStatus::Success)
+        ExitStatus::Success
     }
 }
 
@@ -358,28 +308,9 @@ impl MainLoopCancellationToken {
 enum MainLoopMessage {
     CheckWorkspace,
     CheckCompleted {
-        /// The diagnostics that were found during the check.
-        result: Vec<Diagnostic>,
+        result: Vec<Box<dyn Diagnostic>>,
         revision: u64,
     },
     ApplyChanges(Vec<watch::ChangeEvent>),
     Exit,
 }
-
-fn set_colored_override(color: Option<TerminalColor>) {
-    let Some(color) = color else {
-        return;
-    };
-
-    match color {
-        TerminalColor::Auto => {
-            colored::control::unset_override();
-        }
-        TerminalColor::Always => {
-            colored::control::set_override(true);
-        }
-        TerminalColor::Never => {
-            colored::control::set_override(false);
-        }
-    }
-}

crates/red_knot/tests/cli.rs

@@ -28,7 +28,7 @@ fn config_override() -> anyhow::Result<()> {
         ),
     ])?;
 
-    assert_cmd_snapshot!(case.command(), @r"
+    assert_cmd_snapshot!(case.command(), @r###"
     success: false
     exit_code: 1
     ----- stdout -----
@@ -40,18 +40,16 @@ fn config_override() -> anyhow::Result<()> {
       |       ^^^^^^^^^^^^ Type `<module 'sys'>` has no attribute `last_exc`
       |
 
-    Found 1 diagnostic
 
     ----- stderr -----
-    ");
+    "###);
 
     assert_cmd_snapshot!(case.command().arg("--python-version").arg("3.12"), @r"
-    success: true
-    exit_code: 0
-    ----- stdout -----
-    All checks passed!
+        success: true
+        exit_code: 0
+        ----- stdout -----
 
-    ----- stderr -----
+        ----- stderr -----
     ");
 
     Ok(())
@@ -86,7 +84,7 @@ fn cli_arguments_are_relative_to_the_current_directory() -> anyhow::Result<()> {
             "libs/utils.py",
             r#"
             def add(a: int, b: int) -> int:
-                return a + b
+                a + b
             "#,
         ),
         (
@@ -100,7 +98,7 @@ fn cli_arguments_are_relative_to_the_current_directory() -> anyhow::Result<()> {
     ])?;
 
     // Make sure that the CLI fails when the `libs` directory is not in the search path.
-    assert_cmd_snapshot!(case.command().current_dir(case.root().join("child")), @r"
+    assert_cmd_snapshot!(case.command().current_dir(case.root().join("child")), @r###"
     success: false
     exit_code: 1
     ----- stdout -----
@@ -113,18 +111,16 @@ fn cli_arguments_are_relative_to_the_current_directory() -> anyhow::Result<()> {
     4 | stat = add(10, 15)
       |
 
-    Found 1 diagnostic
 
     ----- stderr -----
-    ");
+    "###);
 
     assert_cmd_snapshot!(case.command().current_dir(case.root().join("child")).arg("--extra-search-path").arg("../libs"), @r"
-    success: true
-    exit_code: 0
-    ----- stdout -----
-    All checks passed!
+        success: true
+        exit_code: 0
+        ----- stdout -----
 
-    ----- stderr -----
+        ----- stderr -----
     ");
 
     Ok(())
@@ -158,7 +154,7 @@ fn paths_in_configuration_files_are_relative_to_the_project_root() -> anyhow::Re
             "libs/utils.py",
             r#"
             def add(a: int, b: int) -> int:
-                return a + b
+                a + b
             "#,
         ),
         (
@@ -172,12 +168,11 @@ fn paths_in_configuration_files_are_relative_to_the_project_root() -> anyhow::Re
     ])?;
 
     assert_cmd_snapshot!(case.command().current_dir(case.root().join("child")), @r"
-    success: true
-    exit_code: 0
-    ----- stdout -----
-    All checks passed!
+        success: true
+        exit_code: 0
+        ----- stdout -----
 
-    ----- stderr -----
+        ----- stderr -----
     ");
 
     Ok(())
@@ -200,7 +195,7 @@ fn configuration_rule_severity() -> anyhow::Result<()> {
 
     // Assert that there's a possibly unresolved reference diagnostic
     // and that division-by-zero has a severity of error by default.
-    assert_cmd_snapshot!(case.command(), @r"
+    assert_cmd_snapshot!(case.command(), @r###"
     success: false
     exit_code: 1
     ----- stdout -----
@@ -219,13 +214,12 @@ fn configuration_rule_severity() -> anyhow::Result<()> {
     5 |     x = a
     6 |
     7 | print(x)  # possibly-unresolved-reference
-      |       ^ Name `x` used when possibly not defined
+      |       - Name `x` used when possibly not defined
       |
 
-    Found 2 diagnostics
 
     ----- stderr -----
-    ");
+    "###);
 
     case.write_file(
         "pyproject.toml",
@@ -236,7 +230,7 @@ fn configuration_rule_severity() -> anyhow::Result<()> {
     "#,
     )?;
 
-    assert_cmd_snapshot!(case.command(), @r"
+    assert_cmd_snapshot!(case.command(), @r###"
     success: true
     exit_code: 0
     ----- stdout -----
@@ -244,15 +238,14 @@ fn configuration_rule_severity() -> anyhow::Result<()> {
      --> <temp_dir>/test.py:2:5
       |
     2 | y = 4 / 0
-      |     ^^^^^ Cannot divide object of type `Literal[4]` by zero
+      |     ----- Cannot divide object of type `Literal[4]` by zero
     3 |
     4 | for a in range(0, y):
       |
 
-    Found 1 diagnostic
 
     ----- stderr -----
-    ");
+    "###);
 
     Ok(())
 }
@@ -276,7 +269,7 @@ fn cli_rule_severity() -> anyhow::Result<()> {
 
     // Assert that there's a possibly unresolved reference diagnostic
     // and that division-by-zero has a severity of error by default.
-    assert_cmd_snapshot!(case.command(), @r"
+    assert_cmd_snapshot!(case.command(), @r###"
     success: false
     exit_code: 1
     ----- stdout -----
@@ -306,13 +299,12 @@ fn cli_rule_severity() -> anyhow::Result<()> {
     7 |     x = a
     8 |
     9 | print(x)  # possibly-unresolved-reference
-      |       ^ Name `x` used when possibly not defined
+      |       - Name `x` used when possibly not defined
       |
 
-    Found 3 diagnostics
 
     ----- stderr -----
-    ");
+    "###);
 
     assert_cmd_snapshot!(
         case
@@ -323,7 +315,7 @@ fn cli_rule_severity() -> anyhow::Result<()> {
             .arg("division-by-zero")
             .arg("--warn")
             .arg("unresolved-import"),
-        @r"
+        @r###"
     success: true
     exit_code: 0
     ----- stdout -----
@@ -331,7 +323,7 @@ fn cli_rule_severity() -> anyhow::Result<()> {
      --> <temp_dir>/test.py:2:8
       |
     2 | import does_not_exit
-      |        ^^^^^^^^^^^^^ Cannot resolve import `does_not_exit`
+      |        ------------- Cannot resolve import `does_not_exit`
     3 |
     4 | y = 4 / 0
       |
@@ -342,15 +334,14 @@ fn cli_rule_severity() -> anyhow::Result<()> {
     2 | import does_not_exit
     3 |
     4 | y = 4 / 0
-      |     ^^^^^ Cannot divide object of type `Literal[4]` by zero
+      |     ----- Cannot divide object of type `Literal[4]` by zero
     5 |
     6 | for a in range(0, y):
       |
 
-    Found 2 diagnostics
 
     ----- stderr -----
-    "
+    "###
     );
 
     Ok(())
@@ -374,7 +365,7 @@ fn cli_rule_severity_precedence() -> anyhow::Result<()> {
 
     // Assert that there's a possibly unresolved reference diagnostic
     // and that division-by-zero has a severity of error by default.
-    assert_cmd_snapshot!(case.command(), @r"
+    assert_cmd_snapshot!(case.command(), @r###"
     success: false
     exit_code: 1
     ----- stdout -----
@@ -393,13 +384,12 @@ fn cli_rule_severity_precedence() -> anyhow::Result<()> {
     5 |     x = a
     6 |
     7 | print(x)  # possibly-unresolved-reference
-      |       ^ Name `x` used when possibly not defined
+      |       - Name `x` used when possibly not defined
       |
 
-    Found 2 diagnostics
 
     ----- stderr -----
-    ");
+    "###);
 
     assert_cmd_snapshot!(
         case
@@ -411,7 +401,7 @@ fn cli_rule_severity_precedence() -> anyhow::Result<()> {
             // Override the error severity with warning
             .arg("--ignore")
             .arg("possibly-unresolved-reference"),
-        @r"
+        @r###"
     success: true
     exit_code: 0
     ----- stdout -----
@@ -419,15 +409,14 @@ fn cli_rule_severity_precedence() -> anyhow::Result<()> {
      --> <temp_dir>/test.py:2:5
       |
     2 | y = 4 / 0
-      |     ^^^^^ Cannot divide object of type `Literal[4]` by zero
+      |     ----- Cannot divide object of type `Literal[4]` by zero
     3 |
     4 | for a in range(0, y):
       |
 
-    Found 1 diagnostic
 
     ----- stderr -----
-    "
+    "###
     );
 
     Ok(())
@@ -447,7 +436,7 @@ fn configuration_unknown_rules() -> anyhow::Result<()> {
         ("test.py", "print(10)"),
     ])?;
 
-    assert_cmd_snapshot!(case.command(), @r#"
+    assert_cmd_snapshot!(case.command(), @r###"
     success: true
     exit_code: 0
     ----- stdout -----
@@ -456,13 +445,12 @@ fn configuration_unknown_rules() -> anyhow::Result<()> {
       |
     2 | [tool.knot.rules]
     3 | division-by-zer = "warn" # incorrect rule name
-      | ^^^^^^^^^^^^^^^ Unknown lint rule `division-by-zer`
+      | --------------- Unknown lint rule `division-by-zer`
       |
 
-    Found 1 diagnostic
 
     ----- stderr -----
-    "#);
+    "###);
 
     Ok(())
 }
@@ -472,16 +460,15 @@ fn configuration_unknown_rules() -> anyhow::Result<()> {
 fn cli_unknown_rules() -> anyhow::Result<()> {
     let case = TestCase::with_file("test.py", "print(10)")?;
 
-    assert_cmd_snapshot!(case.command().arg("--ignore").arg("division-by-zer"), @r"
+    assert_cmd_snapshot!(case.command().arg("--ignore").arg("division-by-zer"), @r###"
     success: true
     exit_code: 0
     ----- stdout -----
     warning: unknown-rule: Unknown lint rule `division-by-zer`
 
-    Found 1 diagnostic
 
     ----- stderr -----
-    ");
+    "###);
 
     Ok(())
 }
@@ -490,7 +477,7 @@ fn cli_unknown_rules() -> anyhow::Result<()> {
 fn exit_code_only_warnings() -> anyhow::Result<()> {
     let case = TestCase::with_file("test.py", r"print(x)  # [unresolved-reference]")?;
 
-    assert_cmd_snapshot!(case.command(), @r"
+    assert_cmd_snapshot!(case.command(), @r###"
     success: true
     exit_code: 0
     ----- stdout -----
@@ -498,13 +485,12 @@ fn exit_code_only_warnings() -> anyhow::Result<()> {
      --> <temp_dir>/test.py:1:7
       |
     1 | print(x)  # [unresolved-reference]
-      |       ^ Name `x` used when not defined
+      |       - Name `x` used when not defined
       |
 
-    Found 1 diagnostic
 
     ----- stderr -----
-    ");
+    "###);
 
     Ok(())
 }
@@ -519,7 +505,7 @@ fn exit_code_only_info() -> anyhow::Result<()> {
         "#,
     )?;
 
-    assert_cmd_snapshot!(case.command(), @r"
+    assert_cmd_snapshot!(case.command(), @r###"
     success: true
     exit_code: 0
     ----- stdout -----
@@ -528,13 +514,12 @@ fn exit_code_only_info() -> anyhow::Result<()> {
       |
     2 | from typing_extensions import reveal_type
     3 | reveal_type(1)
-      | ^^^^^^^^^^^^^^ Revealed type is `Literal[1]`
+      | -------------- info: Revealed type is `Literal[1]`
       |
 
-    Found 1 diagnostic
 
     ----- stderr -----
-    ");
+    "###);
 
     Ok(())
 }
@@ -549,7 +534,7 @@ fn exit_code_only_info_and_error_on_warning_is_true() -> anyhow::Result<()> {
         "#,
     )?;
 
-    assert_cmd_snapshot!(case.command().arg("--error-on-warning"), @r"
+    assert_cmd_snapshot!(case.command().arg("--error-on-warning"), @r###"
     success: true
     exit_code: 0
     ----- stdout -----
@@ -558,13 +543,12 @@ fn exit_code_only_info_and_error_on_warning_is_true() -> anyhow::Result<()> {
       |
     2 | from typing_extensions import reveal_type
     3 | reveal_type(1)
-      | ^^^^^^^^^^^^^^ Revealed type is `Literal[1]`
+      | -------------- info: Revealed type is `Literal[1]`
       |
 
-    Found 1 diagnostic
 
     ----- stderr -----
-    ");
+    "###);
 
     Ok(())
 }
@@ -573,7 +557,7 @@ fn exit_code_only_info_and_error_on_warning_is_true() -> anyhow::Result<()> {
 fn exit_code_no_errors_but_error_on_warning_is_true() -> anyhow::Result<()> {
     let case = TestCase::with_file("test.py", r"print(x)  # [unresolved-reference]")?;
 
-    assert_cmd_snapshot!(case.command().arg("--error-on-warning"), @r"
+    assert_cmd_snapshot!(case.command().arg("--error-on-warning"), @r###"
     success: false
     exit_code: 1
     ----- stdout -----
@@ -581,13 +565,12 @@ fn exit_code_no_errors_but_error_on_warning_is_true() -> anyhow::Result<()> {
      --> <temp_dir>/test.py:1:7
       |
     1 | print(x)  # [unresolved-reference]
-      |       ^ Name `x` used when not defined
+      |       - Name `x` used when not defined
       |
 
-    Found 1 diagnostic
 
     ----- stderr -----
-    ");
+    "###);
 
     Ok(())
 }
@@ -605,7 +588,7 @@ fn exit_code_no_errors_but_error_on_warning_is_enabled_in_configuration() -> any
         ),
     ])?;
 
-    assert_cmd_snapshot!(case.command(), @r"
+    assert_cmd_snapshot!(case.command(), @r###"
     success: false
     exit_code: 1
     ----- stdout -----
@@ -613,13 +596,12 @@ fn exit_code_no_errors_but_error_on_warning_is_enabled_in_configuration() -> any
      --> <temp_dir>/test.py:1:7
       |
     1 | print(x)  # [unresolved-reference]
-      |       ^ Name `x` used when not defined
+      |       - Name `x` used when not defined
       |
 
-    Found 1 diagnostic
 
     ----- stderr -----
-    ");
+    "###);
 
     Ok(())
 }
@@ -634,7 +616,7 @@ fn exit_code_both_warnings_and_errors() -> anyhow::Result<()> {
         "#,
     )?;
 
-    assert_cmd_snapshot!(case.command(), @r"
+    assert_cmd_snapshot!(case.command(), @r###"
     success: false
     exit_code: 1
     ----- stdout -----
@@ -642,7 +624,7 @@ fn exit_code_both_warnings_and_errors() -> anyhow::Result<()> {
      --> <temp_dir>/test.py:2:7
       |
     2 | print(x)     # [unresolved-reference]
-      |       ^ Name `x` used when not defined
+      |       - Name `x` used when not defined
     3 | print(4[1])  # [non-subscriptable]
       |
 
@@ -654,10 +636,9 @@ fn exit_code_both_warnings_and_errors() -> anyhow::Result<()> {
       |       ^ Cannot subscript object of type `Literal[4]` with no `__getitem__` method
       |
 
-    Found 2 diagnostics
 
     ----- stderr -----
-    ");
+    "###);
 
     Ok(())
 }
@@ -672,7 +653,7 @@ fn exit_code_both_warnings_and_errors_and_error_on_warning_is_true() -> anyhow::
         "###,
     )?;
 
-    assert_cmd_snapshot!(case.command().arg("--error-on-warning"), @r"
+    assert_cmd_snapshot!(case.command().arg("--error-on-warning"), @r###"
     success: false
     exit_code: 1
     ----- stdout -----
@@ -680,7 +661,7 @@ fn exit_code_both_warnings_and_errors_and_error_on_warning_is_true() -> anyhow::
      --> <temp_dir>/test.py:2:7
       |
     2 | print(x)     # [unresolved-reference]
-      |       ^ Name `x` used when not defined
+      |       - Name `x` used when not defined
     3 | print(4[1])  # [non-subscriptable]
       |
 
@@ -692,10 +673,9 @@ fn exit_code_both_warnings_and_errors_and_error_on_warning_is_true() -> anyhow::
       |       ^ Cannot subscript object of type `Literal[4]` with no `__getitem__` method
       |
 
-    Found 2 diagnostics
 
     ----- stderr -----
-    ");
+    "###);
 
     Ok(())
 }
@@ -710,7 +690,7 @@ fn exit_code_exit_zero_is_true() -> anyhow::Result<()> {
         "#,
     )?;
 
-    assert_cmd_snapshot!(case.command().arg("--exit-zero"), @r"
+    assert_cmd_snapshot!(case.command().arg("--exit-zero"), @r###"
     success: true
     exit_code: 0
     ----- stdout -----
@@ -718,7 +698,7 @@ fn exit_code_exit_zero_is_true() -> anyhow::Result<()> {
      --> <temp_dir>/test.py:2:7
       |
     2 | print(x)     # [unresolved-reference]
-      |       ^ Name `x` used when not defined
+      |       - Name `x` used when not defined
     3 | print(4[1])  # [non-subscriptable]
       |
 
@@ -730,10 +710,9 @@ fn exit_code_exit_zero_is_true() -> anyhow::Result<()> {
       |       ^ Cannot subscript object of type `Literal[4]` with no `__getitem__` method
       |
 
-    Found 2 diagnostics
 
     ----- stderr -----
-    ");
+    "###);
 
     Ok(())
 }
@@ -770,7 +749,7 @@ fn user_configuration() -> anyhow::Result<()> {
 
     assert_cmd_snapshot!(
         case.command().current_dir(case.root().join("project")).env(config_env_var, config_directory.as_os_str()),
-        @r"
+        @r###"
     success: true
     exit_code: 0
     ----- stdout -----
@@ -778,7 +757,7 @@ fn user_configuration() -> anyhow::Result<()> {
      --> <temp_dir>/project/main.py:2:5
       |
     2 | y = 4 / 0
-      |     ^^^^^ Cannot divide object of type `Literal[4]` by zero
+      |     ----- Cannot divide object of type `Literal[4]` by zero
     3 |
     4 | for a in range(0, y):
       |
@@ -789,13 +768,12 @@ fn user_configuration() -> anyhow::Result<()> {
     5 |     x = a
     6 |
     7 | print(x)
-      |       ^ Name `x` used when possibly not defined
+      |       - Name `x` used when possibly not defined
       |
 
-    Found 2 diagnostics
 
     ----- stderr -----
-    "
+    "###
     );
 
     // The user-level configuration promotes `possibly-unresolved-reference` to an error.
@@ -812,7 +790,7 @@ fn user_configuration() -> anyhow::Result<()> {
 
     assert_cmd_snapshot!(
         case.command().current_dir(case.root().join("project")).env(config_env_var, config_directory.as_os_str()),
-        @r"
+        @r###"
     success: false
     exit_code: 1
     ----- stdout -----
@@ -820,7 +798,7 @@ fn user_configuration() -> anyhow::Result<()> {
      --> <temp_dir>/project/main.py:2:5
       |
     2 | y = 4 / 0
-      |     ^^^^^ Cannot divide object of type `Literal[4]` by zero
+      |     ----- Cannot divide object of type `Literal[4]` by zero
     3 |
     4 | for a in range(0, y):
       |
@@ -834,163 +812,14 @@ fn user_configuration() -> anyhow::Result<()> {
       |       ^ Name `x` used when possibly not defined
       |
 
-    Found 2 diagnostics
 
     ----- stderr -----
-    "
+    "###
     );
 
     Ok(())
 }
 
-#[test]
-fn check_specific_paths() -> anyhow::Result<()> {
-    let case = TestCase::with_files([
-        (
-            "project/main.py",
-            r#"
-            y = 4 / 0  # error: division-by-zero
-            "#,
-        ),
-        (
-            "project/tests/test_main.py",
-            r#"
-            import does_not_exist  # error: unresolved-import
-            "#,
-        ),
-        (
-            "project/other.py",
-            r#"
-            from main2 import z  # error: unresolved-import
-
-            print(z)
-            "#,
-        ),
-    ])?;
-
-    assert_cmd_snapshot!(
-        case.command(),
-        @r"
-    success: false
-    exit_code: 1
-    ----- stdout -----
-    error: lint:unresolved-import
-     --> <temp_dir>/project/tests/test_main.py:2:8
-      |
-    2 | import does_not_exist  # error: unresolved-import
-      |        ^^^^^^^^^^^^^^ Cannot resolve import `does_not_exist`
-      |
-
-    error: lint:division-by-zero
-     --> <temp_dir>/project/main.py:2:5
-      |
-    2 | y = 4 / 0  # error: division-by-zero
-      |     ^^^^^ Cannot divide object of type `Literal[4]` by zero
-      |
-
-    error: lint:unresolved-import
-     --> <temp_dir>/project/other.py:2:6
-      |
-    2 | from main2 import z  # error: unresolved-import
-      |      ^^^^^ Cannot resolve import `main2`
-    3 |
-    4 | print(z)
-      |
-
-    Found 3 diagnostics
-
-    ----- stderr -----
-    "
-    );
-
-    // Now check only the `tests` and `other.py` files.
-    // We should no longer see any diagnostics related to `main.py`.
-    assert_cmd_snapshot!(
-        case.command().arg("project/tests").arg("project/other.py"),
-        @r"
-    success: false
-    exit_code: 1
-    ----- stdout -----
-    error: lint:unresolved-import
-     --> <temp_dir>/project/tests/test_main.py:2:8
-      |
-    2 | import does_not_exist  # error: unresolved-import
-      |        ^^^^^^^^^^^^^^ Cannot resolve import `does_not_exist`
-      |
-
-    error: lint:unresolved-import
-     --> <temp_dir>/project/other.py:2:6
-      |
-    2 | from main2 import z  # error: unresolved-import
-      |      ^^^^^ Cannot resolve import `main2`
-    3 |
-    4 | print(z)
-      |
-
-    Found 2 diagnostics
-
-    ----- stderr -----
-    "
-    );
-
-    Ok(())
-}
-
-#[test]
-fn check_non_existing_path() -> anyhow::Result<()> {
-    let case = TestCase::with_files([])?;
-
-    let mut settings = insta::Settings::clone_current();
-    settings.add_filter(
-        &regex::escape("The system cannot find the path specified. (os error 3)"),
-        "No such file or directory (os error 2)",
-    );
-    let _s = settings.bind_to_scope();
-
-    assert_cmd_snapshot!(
-        case.command().arg("project/main.py").arg("project/tests"),
-        @r"
-    success: false
-    exit_code: 1
-    ----- stdout -----
-    error: io: `<temp_dir>/project/main.py`: No such file or directory (os error 2)
-
-    error: io: `<temp_dir>/project/tests`: No such file or directory (os error 2)
-
-    Found 2 diagnostics
-
-    ----- stderr -----
-    WARN No python files found under the given path(s)
-    "
-    );
-
-    Ok(())
-}
-
-#[test]
-fn concise_diagnostics() -> anyhow::Result<()> {
-    let case = TestCase::with_file(
-        "test.py",
-        r#"
-        print(x)     # [unresolved-reference]
-        print(4[1])  # [non-subscriptable]
-        "#,
-    )?;
-
-    assert_cmd_snapshot!(case.command().arg("--output-format=concise"), @r"
-    success: false
-    exit_code: 1
-    ----- stdout -----
-    warning[lint:unresolved-reference] <temp_dir>/test.py:2:7: Name `x` used when not defined
-    error[lint:non-subscriptable] <temp_dir>/test.py:3:7: Cannot subscript object of type `Literal[4]` with no `__getitem__` method
-    Found 2 diagnostics
-
-    ----- stderr -----
-    ");
-
-    Ok(())
-}
-
 struct TestCase {
     _temp_dir: TempDir,
     _settings_scope: SettingsBindDropGuard,

crates/red_knot/tests/file_watching.rs

@@ -1,4 +1,5 @@
-use std::collections::HashSet;
+#![allow(clippy::disallowed_names)]
+
 use std::io::Write;
 use std::time::{Duration, Instant};
 
@@ -12,9 +13,9 @@ use red_knot_python_semantic::{resolve_module, ModuleName, PythonPlatform};
 use ruff_db::files::{system_path_to_file, File, FileError};
 use ruff_db::source::source_text;
 use ruff_db::system::{
-    file_time_now, OsSystem, System, SystemPath, SystemPathBuf, UserConfigDirectoryOverrideGuard,
+    OsSystem, System, SystemPath, SystemPathBuf, UserConfigDirectoryOverrideGuard,
 };
-use ruff_db::{Db as _, Upcast};
+use ruff_db::Upcast;
 use ruff_python_ast::PythonVersion;
 
 struct TestCase {
@@ -192,29 +193,11 @@ impl TestCase {
         Ok(())
     }
 
-    #[track_caller]
-    fn assert_indexed_project_files(&self, expected: impl IntoIterator<Item = File>) {
-        let mut expected: HashSet<_> = expected.into_iter().collect();
-
-        let actual = self.db().project().files(self.db());
-        for file in &actual {
-            assert!(
-                expected.remove(&file),
-                "Indexed project files contains '{}' which was not expected.",
-                file.path(self.db())
-            );
-        }
-
-        if !expected.is_empty() {
-            let paths: Vec<_> = expected
-                .iter()
-                .map(|file| file.path(self.db()).as_str())
-                .collect();
-            panic!(
-                "Indexed project files are missing the following files: {:?}",
-                paths.join(", ")
-            );
-        }
+    fn collect_project_files(&self) -> Vec<File> {
+        let files = self.db().project().files(self.db());
+        let mut collected: Vec<_> = files.into_iter().collect();
+        collected.sort_unstable_by_key(|file| file.path(self.db()).as_system_path().unwrap());
+        collected
     }
 
     fn system_file(&self, path: impl AsRef<SystemPath>) -> Result<File, FileError> {
@@ -239,15 +222,13 @@ where
     }
 }
 
-trait Setup {
-    fn setup(self, context: &mut SetupContext) -> anyhow::Result<()>;
+trait SetupFiles {
+    fn setup(self, context: &SetupContext) -> anyhow::Result<()>;
 }
 
 struct SetupContext<'a> {
     system: &'a OsSystem,
     root_path: &'a SystemPath,
-    options: Option<Options>,
-    included_paths: Option<Vec<SystemPathBuf>>,
 }
 
 impl<'a> SetupContext<'a> {
@@ -270,77 +251,55 @@ impl<'a> SetupContext<'a> {
     fn join_root_path(&self, relative: impl AsRef<SystemPath>) -> SystemPathBuf {
         self.root_path().join(relative)
     }
-
-    fn write_project_file(
-        &self,
-        relative_path: impl AsRef<SystemPath>,
-        content: &str,
-    ) -> anyhow::Result<()> {
-        let relative_path = relative_path.as_ref();
-        let absolute_path = self.join_project_path(relative_path);
-        Self::write_file_impl(absolute_path, content)
-    }
-
-    fn write_file(
-        &self,
-        relative_path: impl AsRef<SystemPath>,
-        content: &str,
-    ) -> anyhow::Result<()> {
-        let relative_path = relative_path.as_ref();
-        let absolute_path = self.join_root_path(relative_path);
-        Self::write_file_impl(absolute_path, content)
-    }
-
-    fn write_file_impl(path: impl AsRef<SystemPath>, content: &str) -> anyhow::Result<()> {
-        let path = path.as_ref();
-        if let Some(parent) = path.parent() {
-            std::fs::create_dir_all(parent)
-                .with_context(|| format!("Failed to create parent directory for file `{path}`"))?;
-        }
-
-        let mut file = std::fs::File::create(path.as_std_path())
-            .with_context(|| format!("Failed to open file `{path}`"))?;
-        file.write_all(content.as_bytes())
-            .with_context(|| format!("Failed to write to file `{path}`"))?;
-        file.sync_data()?;
-
-        Ok(())
-    }
-
-    fn set_options(&mut self, options: Options) {
-        self.options = Some(options);
-    }
-
-    fn set_included_paths(&mut self, paths: Vec<SystemPathBuf>) {
-        self.included_paths = Some(paths);
-    }
 }
 
-impl<const N: usize, P> Setup for [(P, &'static str); N]
+impl<const N: usize, P> SetupFiles for [(P, &'static str); N]
 where
     P: AsRef<SystemPath>,
 {
-    fn setup(self, context: &mut SetupContext) -> anyhow::Result<()> {
+    fn setup(self, context: &SetupContext) -> anyhow::Result<()> {
         for (relative_path, content) in self {
-            context.write_project_file(relative_path, content)?;
+            let relative_path = relative_path.as_ref();
+            let absolute_path = context.join_project_path(relative_path);
+            if let Some(parent) = absolute_path.parent() {
+                std::fs::create_dir_all(parent).with_context(|| {
+                    format!("Failed to create parent directory for file `{relative_path}`")
+                })?;
+            }
+
+            let mut file = std::fs::File::create(absolute_path.as_std_path())
+                .with_context(|| format!("Failed to open file `{relative_path}`"))?;
+            file.write_all(content.as_bytes())
+                .with_context(|| format!("Failed to write to file `{relative_path}`"))?;
+            file.sync_data()?;
         }
 
         Ok(())
     }
 }
 
-impl<F> Setup for F
+impl<F> SetupFiles for F
 where
-    F: FnOnce(&mut SetupContext) -> anyhow::Result<()>,
+    F: FnOnce(&SetupContext) -> anyhow::Result<()>,
 {
-    fn setup(self, context: &mut SetupContext) -> anyhow::Result<()> {
+    fn setup(self, context: &SetupContext) -> anyhow::Result<()> {
         self(context)
     }
 }
 
 fn setup<F>(setup_files: F) -> anyhow::Result<TestCase>
 where
-    F: Setup,
+    F: SetupFiles,
+{
+    setup_with_options(setup_files, |_context| None)
+}
+
+fn setup_with_options<F>(
+    setup_files: F,
+    create_options: impl FnOnce(&SetupContext) -> Option<Options>,
+) -> anyhow::Result<TestCase>
+where
+    F: SetupFiles,
 {
     let temp_dir = tempfile::tempdir()?;
 
@@ -366,18 +325,16 @@ where
         .with_context(|| format!("Failed to create project directory `{project_path}`"))?;
 
     let system = OsSystem::new(&project_path);
-    let mut setup_context = SetupContext {
+    let setup_context = SetupContext {
         system: &system,
         root_path: &root_path,
-        options: None,
-        included_paths: None,
     };
 
     setup_files
-        .setup(&mut setup_context)
+        .setup(&setup_context)
         .context("Failed to setup test files")?;
 
-    if let Some(options) = setup_context.options {
+    if let Some(options) = create_options(&setup_context) {
         std::fs::write(
             project_path.join("pyproject.toml").as_std_path(),
             toml::to_string(&PyProject {
@@ -391,8 +348,6 @@ where
         .context("Failed to write configuration")?;
     }
 
-    let included_paths = setup_context.included_paths;
-
     let mut project = ProjectMetadata::discover(&project_path, &system)?;
     project.apply_configuration_files(&system)?;
 
@@ -408,11 +363,7 @@ where
             .with_context(|| format!("Failed to create search path `{path}`"))?;
     }
 
-    let mut db = ProjectDatabase::new(project, system)?;
-
-    if let Some(included_paths) = included_paths {
-        db.project().set_included_paths(&mut db, included_paths);
-    }
+    let db = ProjectDatabase::new(project, system)?;
 
     let (sender, receiver) = crossbeam::channel::unbounded();
     let watcher = directory_watcher(move |events| sender.send(events).unwrap())
@@ -462,7 +413,7 @@ fn update_file(path: impl AsRef<SystemPath>, content: &str) -> anyhow::Result<()
 
         std::thread::sleep(Duration::from_nanos(10));
 
-        filetime::set_file_handle_times(&file, None, Some(file_time_now()))?;
+        filetime::set_file_handle_times(&file, None, Some(filetime::FileTime::now()))?;
     }
 }
 
@@ -474,7 +425,7 @@ fn new_file() -> anyhow::Result<()> {
     let foo_path = case.project_path("foo.py");
 
     assert_eq!(case.system_file(&foo_path), Err(FileError::NotFound));
-    case.assert_indexed_project_files([bar_file]);
+    assert_eq!(&case.collect_project_files(), &[bar_file]);
 
     std::fs::write(foo_path.as_std_path(), "print('Hello')")?;
 
@@ -484,7 +435,7 @@ fn new_file() -> anyhow::Result<()> {
 
     let foo = case.system_file(&foo_path).expect("foo.py to exist.");
 
-    case.assert_indexed_project_files([bar_file, foo]);
+    assert_eq!(&case.collect_project_files(), &[bar_file, foo]);
 
     Ok(())
 }
@@ -497,7 +448,7 @@ fn new_ignored_file() -> anyhow::Result<()> {
     let foo_path = case.project_path("foo.py");
 
     assert_eq!(case.system_file(&foo_path), Err(FileError::NotFound));
-    case.assert_indexed_project_files([bar_file]);
+    assert_eq!(&case.collect_project_files(), &[bar_file]);
 
     std::fs::write(foo_path.as_std_path(), "print('Hello')")?;
 
@@ -506,132 +457,7 @@ fn new_ignored_file() -> anyhow::Result<()> {
     case.apply_changes(changes);
 
     assert!(case.system_file(&foo_path).is_ok());
-    case.assert_indexed_project_files([bar_file]);
-
-    Ok(())
-}
-
-#[test]
-fn new_non_project_file() -> anyhow::Result<()> {
-    let mut case = setup(|context: &mut SetupContext| {
-        context.write_project_file("bar.py", "")?;
-        context.set_options(Options {
-            environment: Some(EnvironmentOptions {
-                extra_paths: Some(vec![RelativePathBuf::cli(
-                    context.join_root_path("site_packages"),
-                )]),
-                ..EnvironmentOptions::default()
-            }),
-            ..Options::default()
-        });
-
-        Ok(())
-    })?;
-
-    let bar_path = case.project_path("bar.py");
-    let bar_file = case.system_file(&bar_path).unwrap();
-
-    case.assert_indexed_project_files([bar_file]);
-
-    // Add a file to site packages
-    let black_path = case.root_path().join("site_packages/black.py");
-    std::fs::write(black_path.as_std_path(), "print('Hello')")?;
-
-    let changes = case.stop_watch(event_for_file("black.py"));
-
-    case.apply_changes(changes);
-
-    assert!(case.system_file(&black_path).is_ok());
-
-    // The file should not have been added to the project files
-    case.assert_indexed_project_files([bar_file]);
-
-    Ok(())
-}
-
-#[test]
-fn new_files_with_explicit_included_paths() -> anyhow::Result<()> {
-    let mut case = setup(|context: &mut SetupContext| {
-        context.write_project_file("src/main.py", "")?;
-        context.write_project_file("src/sub/__init__.py", "")?;
-        context.write_project_file("src/test.py", "")?;
-        context.set_included_paths(vec![
-            context.join_project_path("src/main.py"),
-            context.join_project_path("src/sub"),
-        ]);
-        Ok(())
-    })?;
-
-    let main_path = case.project_path("src/main.py");
-    let main_file = case.system_file(&main_path).unwrap();
-
-    let sub_init_path = case.project_path("src/sub/__init__.py");
-    let sub_init = case.system_file(&sub_init_path).unwrap();
-
-    case.assert_indexed_project_files([main_file, sub_init]);
-
-    // Write a new file to `sub` which is an included path
-    let sub_a_path = case.project_path("src/sub/a.py");
-    std::fs::write(sub_a_path.as_std_path(), "print('Hello')")?;
-
-    // and write a second file in the root directory -- this should not be included
-    let test2_path = case.project_path("src/test2.py");
-    std::fs::write(test2_path.as_std_path(), "print('Hello')")?;
-
-    let changes = case.stop_watch(event_for_file("test2.py"));
-
-    case.apply_changes(changes);
-
-    let sub_a_file = case.system_file(&sub_a_path).expect("sub/a.py to exist");
-
-    case.assert_indexed_project_files([main_file, sub_init, sub_a_file]);
-
-    Ok(())
-}
-
-#[test]
-fn new_file_in_included_out_of_project_directory() -> anyhow::Result<()> {
-    let mut case = setup(|context: &mut SetupContext| {
-        context.write_project_file("src/main.py", "")?;
-        context.write_project_file("script.py", "")?;
-        context.write_file("outside_project/a.py", "")?;
-
-        context.set_included_paths(vec![
-            context.join_root_path("outside_project"),
-            context.join_project_path("src"),
-        ]);
-        Ok(())
-    })?;
-
-    let main_path = case.project_path("src/main.py");
-    let main_file = case.system_file(&main_path).unwrap();
-
-    let outside_a_path = case.root_path().join("outside_project/a.py");
-    let outside_a = case.system_file(&outside_a_path).unwrap();
-
-    case.assert_indexed_project_files([outside_a, main_file]);
-
-    // Write a new file to `src` which should be watched
-    let src_a = case.project_path("src/a.py");
-    std::fs::write(src_a.as_std_path(), "print('Hello')")?;
-
-    // and write a second file to `outside_project` which should be watched too
-    let outside_b_path = case.root_path().join("outside_project/b.py");
-    std::fs::write(outside_b_path.as_std_path(), "print('Hello')")?;
-
-    // and a third file in the project's root that should not be included
-    let script2_path = case.project_path("script2.py");
-    std::fs::write(script2_path.as_std_path(), "print('Hello')")?;
-
-    let changes = case.stop_watch(event_for_file("script2.py"));
-
-    case.apply_changes(changes);
-
-    let src_a_file = case.system_file(&src_a).unwrap();
-    let outside_b_file = case.system_file(&outside_b_path).unwrap();
-
-    // The file should not have been added to the project files
-    case.assert_indexed_project_files([main_file, outside_a, outside_b_file, src_a_file]);
+    assert_eq!(&case.collect_project_files(), &[bar_file]);
 
     Ok(())
 }
@@ -644,7 +470,7 @@ fn changed_file() -> anyhow::Result<()> {
 
     let foo = case.system_file(&foo_path)?;
     assert_eq!(source_text(case.db(), foo).as_str(), foo_source);
-    case.assert_indexed_project_files([foo]);
+    assert_eq!(&case.collect_project_files(), &[foo]);
 
     update_file(&foo_path, "print('Version 2')")?;
 
@@ -655,7 +481,7 @@ fn changed_file() -> anyhow::Result<()> {
     case.apply_changes(changes);
 
     assert_eq!(source_text(case.db(), foo).as_str(), "print('Version 2')");
-    case.assert_indexed_project_files([foo]);
+    assert_eq!(&case.collect_project_files(), &[foo]);
 
     Ok(())
 }
@@ -669,7 +495,7 @@ fn deleted_file() -> anyhow::Result<()> {
     let foo = case.system_file(&foo_path)?;
 
     assert!(foo.exists(case.db()));
-    case.assert_indexed_project_files([foo]);
+    assert_eq!(&case.collect_project_files(), &[foo]);
 
     std::fs::remove_file(foo_path.as_std_path())?;
 
@@ -678,7 +504,7 @@ fn deleted_file() -> anyhow::Result<()> {
     case.apply_changes(changes);
 
     assert!(!foo.exists(case.db()));
-    case.assert_indexed_project_files([]);
+    assert_eq!(&case.collect_project_files(), &[] as &[File]);
 
     Ok(())
 }
@@ -698,7 +524,7 @@ fn move_file_to_trash() -> anyhow::Result<()> {
     let foo = case.system_file(&foo_path)?;
 
     assert!(foo.exists(case.db()));
-    case.assert_indexed_project_files([foo]);
+    assert_eq!(&case.collect_project_files(), &[foo]);
 
     std::fs::rename(
         foo_path.as_std_path(),
@@ -710,7 +536,7 @@ fn move_file_to_trash() -> anyhow::Result<()> {
     case.apply_changes(changes);
 
     assert!(!foo.exists(case.db()));
-    case.assert_indexed_project_files([]);
+    assert_eq!(&case.collect_project_files(), &[] as &[File]);
 
     Ok(())
 }
@@ -728,7 +554,7 @@ fn move_file_to_project() -> anyhow::Result<()> {
     let foo_in_project = case.project_path("foo.py");
 
     assert!(case.system_file(&foo_path).is_ok());
-    case.assert_indexed_project_files([bar]);
+    assert_eq!(&case.collect_project_files(), &[bar]);
 
     std::fs::rename(foo_path.as_std_path(), foo_in_project.as_std_path())?;
 
@@ -739,7 +565,7 @@ fn move_file_to_project() -> anyhow::Result<()> {
     let foo_in_project = case.system_file(&foo_in_project)?;
 
     assert!(foo_in_project.exists(case.db()));
-    case.assert_indexed_project_files([bar, foo_in_project]);
+    assert_eq!(&case.collect_project_files(), &[bar, foo_in_project]);
 
     Ok(())
 }
@@ -753,7 +579,7 @@ fn rename_file() -> anyhow::Result<()> {
 
     let foo = case.system_file(&foo_path)?;
 
-    case.assert_indexed_project_files([foo]);
+    assert_eq!(case.collect_project_files(), [foo]);
 
     std::fs::rename(foo_path.as_std_path(), bar_path.as_std_path())?;
 
@@ -766,7 +592,7 @@ fn rename_file() -> anyhow::Result<()> {
     let bar = case.system_file(&bar_path)?;
 
     assert!(bar.exists(case.db()));
-    case.assert_indexed_project_files([bar]);
+    assert_eq!(case.collect_project_files(), [bar]);
 
     Ok(())
 }
@@ -792,7 +618,7 @@ fn directory_moved_to_project() -> anyhow::Result<()> {
     );
 
     assert_eq!(sub_a_module, None);
-    case.assert_indexed_project_files([bar]);
+    assert_eq!(case.collect_project_files(), &[bar]);
 
     let sub_new_path = case.project_path("sub");
     std::fs::rename(sub_original_path.as_std_path(), sub_new_path.as_std_path())
@@ -816,7 +642,7 @@ fn directory_moved_to_project() -> anyhow::Result<()> {
     )
     .is_some());
 
-    case.assert_indexed_project_files([bar, init_file, a_file]);
+    assert_eq!(case.collect_project_files(), &[bar, init_file, a_file]);
 
     Ok(())
 }
@@ -844,7 +670,7 @@ fn directory_moved_to_trash() -> anyhow::Result<()> {
         .system_file(sub_path.join("a.py"))
         .expect("a.py to exist");
 
-    case.assert_indexed_project_files([bar, init_file, a_file]);
+    assert_eq!(case.collect_project_files(), &[bar, init_file, a_file]);
 
     std::fs::create_dir(case.root_path().join(".trash").as_std_path())?;
     let trashed_sub = case.root_path().join(".trash/sub");
@@ -865,7 +691,7 @@ fn directory_moved_to_trash() -> anyhow::Result<()> {
     assert!(!init_file.exists(case.db()));
     assert!(!a_file.exists(case.db()));
 
-    case.assert_indexed_project_files([bar]);
+    assert_eq!(case.collect_project_files(), &[bar]);
 
     Ok(())
 }
@@ -899,7 +725,7 @@ fn directory_renamed() -> anyhow::Result<()> {
         .system_file(sub_path.join("a.py"))
         .expect("a.py to exist");
 
-    case.assert_indexed_project_files([bar, sub_init, sub_a]);
+    assert_eq!(case.collect_project_files(), &[bar, sub_init, sub_a]);
 
     let foo_baz = case.project_path("foo/baz");
 
@@ -941,7 +767,10 @@ fn directory_renamed() -> anyhow::Result<()> {
     assert!(foo_baz_init.exists(case.db()));
     assert!(foo_baz_a.exists(case.db()));
 
-    case.assert_indexed_project_files([bar, foo_baz_init, foo_baz_a]);
+    assert_eq!(
+        case.collect_project_files(),
+        &[bar, foo_baz_init, foo_baz_a]
+    );
 
     Ok(())
 }
@@ -970,7 +799,7 @@ fn directory_deleted() -> anyhow::Result<()> {
     let a_file = case
         .system_file(sub_path.join("a.py"))
         .expect("a.py to exist");
-    case.assert_indexed_project_files([bar, init_file, a_file]);
+    assert_eq!(case.collect_project_files(), &[bar, init_file, a_file]);
 
     std::fs::remove_dir_all(sub_path.as_std_path())
         .with_context(|| "Failed to remove the sub directory")?;
@@ -988,17 +817,15 @@ fn directory_deleted() -> anyhow::Result<()> {
 
     assert!(!init_file.exists(case.db()));
     assert!(!a_file.exists(case.db()));
-    case.assert_indexed_project_files([bar]);
+    assert_eq!(case.collect_project_files(), &[bar]);
 
     Ok(())
 }
 
 #[test]
 fn search_path() -> anyhow::Result<()> {
-    let mut case = setup(|context: &mut SetupContext| {
-        context.write_project_file("bar.py", "import sub.a")?;
-
-        context.set_options(Options {
+    let mut case = setup_with_options([("bar.py", "import sub.a")], |context| {
+        Some(Options {
             environment: Some(EnvironmentOptions {
                 extra_paths: Some(vec![RelativePathBuf::cli(
                     context.join_root_path("site_packages"),
@@ -1006,8 +833,7 @@ fn search_path() -> anyhow::Result<()> {
                 ..EnvironmentOptions::default()
             }),
             ..Options::default()
-        });
-        Ok(())
+        })
     })?;
 
     let site_packages = case.root_path().join("site_packages");
@@ -1024,7 +850,10 @@ fn search_path() -> anyhow::Result<()> {
     case.apply_changes(changes);
 
     assert!(resolve_module(case.db().upcast(), &ModuleName::new_static("a").unwrap()).is_some());
-    case.assert_indexed_project_files([case.system_file(case.project_path("bar.py")).unwrap()]);
+    assert_eq!(
+        case.collect_project_files(),
+        &[case.system_file(case.project_path("bar.py")).unwrap()]
+    );
 
     Ok(())
 }
@@ -1061,9 +890,8 @@ fn add_search_path() -> anyhow::Result<()> {
 
 #[test]
 fn remove_search_path() -> anyhow::Result<()> {
-    let mut case = setup(|context: &mut SetupContext| {
-        context.write_project_file("bar.py", "import sub.a")?;
-        context.set_options(Options {
+    let mut case = setup_with_options([("bar.py", "import sub.a")], |context| {
+        Some(Options {
             environment: Some(EnvironmentOptions {
                 extra_paths: Some(vec![RelativePathBuf::cli(
                     context.join_root_path("site_packages"),
@@ -1071,9 +899,7 @@ fn remove_search_path() -> anyhow::Result<()> {
                 ..EnvironmentOptions::default()
             }),
             ..Options::default()
-        });
-
-        Ok(())
+        })
     })?;
 
     // Remove site packages from the search path settings.
@@ -1096,40 +922,40 @@ fn remove_search_path() -> anyhow::Result<()> {
 
 #[test]
 fn change_python_version_and_platform() -> anyhow::Result<()> {
-    let mut case = setup(|context: &mut SetupContext| {
+    let mut case = setup_with_options(
         // `sys.last_exc` is a Python 3.12 only feature
         // `os.getegid()` is Unix only
-        context.write_project_file(
+        [(
             "bar.py",
             r#"
 import sys
 import os
 print(sys.last_exc, os.getegid())
 "#,
-        )?;
-        context.set_options(Options {
-            environment: Some(EnvironmentOptions {
-                python_version: Some(RangedValue::cli(PythonVersion::PY311)),
-                python_platform: Some(RangedValue::cli(PythonPlatform::Identifier(
-                    "win32".to_string(),
-                ))),
-                ..EnvironmentOptions::default()
-            }),
-            ..Options::default()
-        });
-
-        Ok(())
-    })?;
+        )],
+        |_context| {
+            Some(Options {
+                environment: Some(EnvironmentOptions {
+                    python_version: Some(RangedValue::cli(PythonVersion::PY311)),
+                    python_platform: Some(RangedValue::cli(PythonPlatform::Identifier(
+                        "win32".to_string(),
+                    ))),
+                    ..EnvironmentOptions::default()
+                }),
+                ..Options::default()
+            })
+        },
+    )?;
 
     let diagnostics = case.db.check().context("Failed to check project.")?;
 
     assert_eq!(diagnostics.len(), 2);
     assert_eq!(
-        diagnostics[0].primary_message(),
+        diagnostics[0].message(),
         "Type `<module 'sys'>` has no attribute `last_exc`"
     );
     assert_eq!(
-        diagnostics[1].primary_message(),
+        diagnostics[1].message(),
         "Type `<module 'os'>` has no attribute `getegid`"
     );
 
@@ -1154,35 +980,38 @@ print(sys.last_exc, os.getegid())
 
 #[test]
 fn changed_versions_file() -> anyhow::Result<()> {
-    let mut case = setup(|context: &mut SetupContext| {
-        std::fs::write(
-            context.join_project_path("bar.py").as_std_path(),
-            "import sub.a",
-        )?;
-        std::fs::create_dir_all(context.join_root_path("typeshed/stdlib").as_std_path())?;
-        std::fs::write(
-            context
-                .join_root_path("typeshed/stdlib/VERSIONS")
-                .as_std_path(),
-            "",
-        )?;
-        std::fs::write(
-            context
-                .join_root_path("typeshed/stdlib/os.pyi")
-                .as_std_path(),
-            "# not important",
-        )?;
+    let mut case = setup_with_options(
+        |context: &SetupContext| {
+            std::fs::write(
+                context.join_project_path("bar.py").as_std_path(),
+                "import sub.a",
+            )?;
+            std::fs::create_dir_all(context.join_root_path("typeshed/stdlib").as_std_path())?;
+            std::fs::write(
+                context
+                    .join_root_path("typeshed/stdlib/VERSIONS")
+                    .as_std_path(),
+                "",
+            )?;
+            std::fs::write(
+                context
+                    .join_root_path("typeshed/stdlib/os.pyi")
+                    .as_std_path(),
+                "# not important",
+            )?;
 
-        context.set_options(Options {
-            environment: Some(EnvironmentOptions {
-                typeshed: Some(RelativePathBuf::cli(context.join_root_path("typeshed"))),
-                ..EnvironmentOptions::default()
-            }),
-            ..Options::default()
-        });
-
-        Ok(())
-    })?;
+            Ok(())
+        },
+        |context| {
+            Some(Options {
+                environment: Some(EnvironmentOptions {
+                    typeshed: Some(RelativePathBuf::cli(context.join_root_path("typeshed"))),
+                    ..EnvironmentOptions::default()
+                }),
+                ..Options::default()
+            })
+        },
+    )?;
 
     // Unset the custom typeshed directory.
     assert_eq!(
@@ -1227,7 +1056,7 @@ fn changed_versions_file() -> anyhow::Result<()> {
 /// we're seeing is that Windows only emits a single event, similar to Linux.
 #[test]
 fn hard_links_in_project() -> anyhow::Result<()> {
-    let mut case = setup(|context: &mut SetupContext| {
+    let mut case = setup(|context: &SetupContext| {
         let foo_path = context.join_project_path("foo.py");
         std::fs::write(foo_path.as_std_path(), "print('Version 1')")?;
 
@@ -1246,7 +1075,6 @@ fn hard_links_in_project() -> anyhow::Result<()> {
 
     assert_eq!(source_text(case.db(), foo).as_str(), "print('Version 1')");
     assert_eq!(source_text(case.db(), bar).as_str(), "print('Version 1')");
-    case.assert_indexed_project_files([bar, foo]);
 
     // Write to the hard link target.
     update_file(foo_path, "print('Version 2')").context("Failed to update foo.py")?;
@@ -1299,7 +1127,7 @@ fn hard_links_in_project() -> anyhow::Result<()> {
     ignore = "windows doesn't support observing changes to hard linked files."
 )]
 fn hard_links_to_target_outside_project() -> anyhow::Result<()> {
-    let mut case = setup(|context: &mut SetupContext| {
+    let mut case = setup(|context: &SetupContext| {
         let foo_path = context.join_root_path("foo.py");
         std::fs::write(foo_path.as_std_path(), "print('Version 1')")?;
 
@@ -1407,7 +1235,7 @@ mod unix {
         ignore = "FSEvents doesn't emit change events for symlinked directories outside of the watched paths."
     )]
     fn symlink_target_outside_watched_paths() -> anyhow::Result<()> {
-        let mut case = setup(|context: &mut SetupContext| {
+        let mut case = setup(|context: &SetupContext| {
             // Set up the symlink target.
             let link_target = context.join_root_path("bar");
             std::fs::create_dir_all(link_target.as_std_path())
@@ -1488,7 +1316,7 @@ mod unix {
     /// ```
     #[test]
     fn symlink_inside_project() -> anyhow::Result<()> {
-        let mut case = setup(|context: &mut SetupContext| {
+        let mut case = setup(|context: &SetupContext| {
             // Set up the symlink target.
             let link_target = context.join_project_path("patched/bar");
             std::fs::create_dir_all(link_target.as_std_path())
@@ -1526,8 +1354,6 @@ mod unix {
         );
         assert_eq!(baz.file().path(case.db()).as_system_path(), Some(&*bar_baz));
 
-        case.assert_indexed_project_files([patched_bar_baz_file]);
-
         // Write to the symlink target.
         update_file(&patched_bar_baz, "def baz(): print('Version 2')")
             .context("Failed to update bar/baz.py")?;
@@ -1563,7 +1389,6 @@ mod unix {
             bar_baz_text = bar_baz_text.as_str()
         );
 
-        case.assert_indexed_project_files([patched_bar_baz_file]);
         Ok(())
     }
 
@@ -1581,39 +1406,43 @@ mod unix {
     /// ```
     #[test]
     fn symlinked_module_search_path() -> anyhow::Result<()> {
-        let mut case = setup(|context: &mut SetupContext| {
-            // Set up the symlink target.
-            let site_packages = context.join_root_path("site-packages");
-            let bar = site_packages.join("bar");
-            std::fs::create_dir_all(bar.as_std_path()).context("Failed to create bar directory")?;
-            let baz_original = bar.join("baz.py");
-            std::fs::write(baz_original.as_std_path(), "def baz(): ...")
-                .context("Failed to write baz.py")?;
+        let mut case = setup_with_options(
+            |context: &SetupContext| {
+                // Set up the symlink target.
+                let site_packages = context.join_root_path("site-packages");
+                let bar = site_packages.join("bar");
+                std::fs::create_dir_all(bar.as_std_path())
+                    .context("Failed to create bar directory")?;
+                let baz_original = bar.join("baz.py");
+                std::fs::write(baz_original.as_std_path(), "def baz(): ...")
+                    .context("Failed to write baz.py")?;
 
-            // Symlink the site packages in the venv to the global site packages
-            let venv_site_packages =
-                context.join_project_path(".venv/lib/python3.12/site-packages");
-            std::fs::create_dir_all(venv_site_packages.parent().unwrap())
-                .context("Failed to create .venv directory")?;
-            std::os::unix::fs::symlink(
-                site_packages.as_std_path(),
-                venv_site_packages.as_std_path(),
-            )
-            .context("Failed to create symlink to site-packages")?;
+                // Symlink the site packages in the venv to the global site packages
+                let venv_site_packages =
+                    context.join_project_path(".venv/lib/python3.12/site-packages");
+                std::fs::create_dir_all(venv_site_packages.parent().unwrap())
+                    .context("Failed to create .venv directory")?;
+                std::os::unix::fs::symlink(
+                    site_packages.as_std_path(),
+                    venv_site_packages.as_std_path(),
+                )
+                .context("Failed to create symlink to site-packages")?;
 
-            context.set_options(Options {
-                environment: Some(EnvironmentOptions {
-                    extra_paths: Some(vec![RelativePathBuf::cli(
-                        ".venv/lib/python3.12/site-packages",
-                    )]),
-                    python_version: Some(RangedValue::cli(PythonVersion::PY312)),
-                    ..EnvironmentOptions::default()
-                }),
-                ..Options::default()
-            });
-
-            Ok(())
-        })?;
+                Ok(())
+            },
+            |_context| {
+                Some(Options {
+                    environment: Some(EnvironmentOptions {
+                        extra_paths: Some(vec![RelativePathBuf::cli(
+                            ".venv/lib/python3.12/site-packages",
+                        )]),
+                        python_version: Some(RangedValue::cli(PythonVersion::PY312)),
+                        ..EnvironmentOptions::default()
+                    }),
+                    ..Options::default()
+                })
+            },
+        )?;
 
         let baz = resolve_module(
             case.db().upcast(),
@@ -1640,8 +1469,6 @@ mod unix {
             Some(&*baz_original)
         );
 
-        case.assert_indexed_project_files([]);
-
         // Write to the symlink target.
         update_file(&baz_original, "def baz(): print('Version 2')")
             .context("Failed to update bar/baz.py")?;
@@ -1667,15 +1494,13 @@ mod unix {
             "def baz(): print('Version 2')"
         );
 
-        case.assert_indexed_project_files([]);
-
         Ok(())
     }
 }
 
 #[test]
 fn nested_projects_delete_root() -> anyhow::Result<()> {
-    let mut case = setup(|context: &mut SetupContext| {
+    let mut case = setup(|context: &SetupContext| {
         std::fs::write(
             context.join_project_path("pyproject.toml").as_std_path(),
             r#"
@@ -1717,7 +1542,7 @@ fn nested_projects_delete_root() -> anyhow::Result<()> {
 fn changes_to_user_configuration() -> anyhow::Result<()> {
     let mut _config_dir_override: Option<UserConfigDirectoryOverrideGuard> = None;
 
-    let mut case = setup(|context: &mut SetupContext| {
+    let mut case = setup(|context: &SetupContext| {
         std::fs::write(
             context.join_project_path("pyproject.toml").as_std_path(),
             r#"
@@ -1788,82 +1613,3 @@ fn changes_to_user_configuration() -> anyhow::Result<()> {
 
     Ok(())
 }
-
-/// Tests that renaming a file from `lib.py` to `Lib.py` is correctly reflected.
-///
-/// This test currently fails on case-insensitive systems because `Files` is case-sensitive
-/// but the `System::metadata` call isn't. This means that
-/// Red Knot considers both `Lib.py` and `lib.py` to exist when only `lib.py` does
-///
-/// The incoming change events then are no-ops because they don't change either file's
-/// status nor does it update their last modified time (renaming a file doesn't bump it's
-/// last modified timestamp).
-///
-/// Fixing this requires to either make `Files` case-insensitive and store the
-/// real-case path (if it differs) on `File` or make `Files` use a
-/// case-sensitive `System::metadata` call. This does open the question if all
-/// `System` calls should be case sensitive. This would be the most consistent
-/// but might be hard to pull off.
-///
-/// What the right solution is also depends on if Red Knot itself should be case
-/// sensitive or not. E.g. should `include="src"` be case sensitive on all systems
-/// or only on case-sensitive systems?
-///
-/// Lastly, whatever solution we pick must also work well with VS Code which,
-/// unfortunately ,doesn't propagate casing-only renames.
-/// <https://github.com/rust-lang/rust-analyzer/issues/9581>
-#[ignore]
-#[test]
-fn rename_files_casing_only() -> anyhow::Result<()> {
-    let mut case = setup([("lib.py", "class Foo: ...")])?;
-
-    assert!(
-        resolve_module(case.db(), &ModuleName::new("lib").unwrap()).is_some(),
-        "Expected `lib` module to exist."
-    );
-    assert_eq!(
-        resolve_module(case.db(), &ModuleName::new("Lib").unwrap()),
-        None,
-        "Expected `Lib` module not to exist"
-    );
-
-    // Now rename `lib.py` to `Lib.py`
-    if case.db().system().case_sensitivity().is_case_sensitive() {
-        std::fs::rename(
-            case.project_path("lib.py").as_std_path(),
-            case.project_path("Lib.py").as_std_path(),
-        )
-        .context("Failed to rename `lib.py` to `Lib.py`")?;
-    } else {
-        // On case-insensitive file systems, renaming a file to a different casing is a no-op.
-        // Rename to a different name first
-        std::fs::rename(
-            case.project_path("lib.py").as_std_path(),
-            case.project_path("temp.py").as_std_path(),
-        )
-        .context("Failed to rename `lib.py` to `temp.py`")?;
-
-        std::fs::rename(
-            case.project_path("temp.py").as_std_path(),
-            case.project_path("Lib.py").as_std_path(),
-        )
-        .context("Failed to rename `temp.py` to `Lib.py`")?;
-    }
-
-    let changes = case.stop_watch(event_for_file("Lib.py"));
-    case.apply_changes(changes);
-
-    // Resolving `lib` should now fail but `Lib` should now succeed
-    assert_eq!(
-        resolve_module(case.db(), &ModuleName::new("lib").unwrap()),
-        None,
-        "Expected `lib` module to no longer exist."
-    );
-
-    assert!(
-        resolve_module(case.db(), &ModuleName::new("Lib").unwrap()).is_some(),
-        "Expected `Lib` module to exist"
-    );
-
-    Ok(())
-}

crates/red_knot_ide/Cargo.toml

@@ -1,30 +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 }
-
-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

@@ -1,912 +0,0 @@
-use crate::find_node::covering_node;
-use crate::{Db, HasNavigationTargets, NavigationTargets, RangedValue};
-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 = match goto_target {
-        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,
-    };
-
-    tracing::debug!(
-        "Inferred type of covering node is {}",
-        ty.display(db.upcast())
-    );
-
-    Some(RangedValue {
-        range: FileRange::new(file, goto_target.range()),
-        value: ty.navigation_targets(db),
-    })
-}
-
-#[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 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).find(|token| {
-        matches!(
-            token.kind(),
-            TokenKind::Name
-                | TokenKind::String
-                | TokenKind::Complex
-                | TokenKind::Float
-                | TokenKind::Int
-        )
-    })?;
-    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 std::fmt::Write;
-
-    use crate::db::tests::TestDb;
-    use crate::{goto_type_definition, NavigationTarget};
-    use insta::assert_snapshot;
-    use insta::internals::SettingsBindDropGuard;
-    use red_knot_python_semantic::{
-        Program, ProgramSettings, PythonPath, PythonPlatform, SearchPathSettings,
-    };
-    use ruff_db::diagnostic::{
-        Annotation, Diagnostic, DiagnosticFormat, DiagnosticId, DisplayDiagnosticConfig, LintName,
-        Severity, Span, SubDiagnostic,
-    };
-    use ruff_db::files::{system_path_to_file, File, FileRange};
-    use ruff_db::system::{DbWithWritableSystem, SystemPath, SystemPathBuf};
-    use ruff_python_ast::PythonVersion;
-    use ruff_text_size::{Ranged, TextSize};
-
-    #[test]
-    fn goto_type_of_expression_with_class_type() {
-        let test = goto_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 = goto_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 = goto_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 = goto_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 = goto_test(
-            r#"
-            a: str = "test"
-
-            a<CURSOR>
-            "#,
-        );
-
-        assert_snapshot!(test.goto_type_definition(), @r###"
-        info: lint:goto-type-definition: Type definition
-           --> stdlib/builtins.pyi:443:7
-            |
-        441 |     def __getitem__(self, key: int, /) -> str | int | None: ...
-        442 |
-        443 | class str(Sequence[str]):
-            |       ^^^
-        444 |     @overload
-        445 |     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 = goto_test(
-            r#"
-            a: str = "te<CURSOR>st"
-            "#,
-        );
-
-        assert_snapshot!(test.goto_type_definition(), @r###"
-        info: lint:goto-type-definition: Type definition
-           --> stdlib/builtins.pyi:443:7
-            |
-        441 |     def __getitem__(self, key: int, /) -> str | int | None: ...
-        442 |
-        443 | class str(Sequence[str]):
-            |       ^^^
-        444 |     @overload
-        445 |     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 = goto_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 = goto_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 = goto_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 = goto_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:443:7
-            |
-        441 |     def __getitem__(self, key: int, /) -> str | int | None: ...
-        442 |
-        443 | class str(Sequence[str]):
-            |       ^^^
-        444 |     @overload
-        445 |     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 = goto_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:234:7
-            |
-        232 | _LiteralInteger = _PositiveInteger | _NegativeInteger | Literal[0]  # noqa: Y026  # TODO: Use TypeAlias once mypy bugs are fixed
-        233 |
-        234 | class int:
-            |       ^^^
-        235 |     @overload
-        236 |     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 = goto_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:1098:7
-             |
-        1096 |         def __class_getitem__(cls, item: Any, /) -> GenericAlias: ...
-        1097 |
-        1098 | class dict(MutableMapping[_KT, _VT]):
-             |       ^^^^
-        1099 |     # __init__ should be kept roughly in line with `collections.UserDict.__init__`, which has similar semantics
-        1100 |     # 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 = goto_test(
-            r#"
-            def foo(a: str):
-                a<CURSOR>
-            "#,
-        );
-
-        // FIXME: This should go to `str`
-        assert_snapshot!(test.goto_type_definition(), @r###"
-        info: lint:goto-type-definition: Type definition
-           --> stdlib/builtins.pyi:443:7
-            |
-        441 |     def __getitem__(self, key: int, /) -> str | int | None: ...
-        442 |
-        443 | class str(Sequence[str]):
-            |       ^^^
-        444 |     @overload
-        445 |     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 = goto_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 = goto_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 = goto_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:443:7
-            |
-        441 |     def __getitem__(self, key: int, /) -> str | int | None: ...
-        442 |
-        443 | class str(Sequence[str]):
-            |       ^^^
-        444 |     @overload
-        445 |     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 = goto_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/builtins.pyi:443:7
-            |
-        441 |     def __getitem__(self, key: int, /) -> str | int | None: ...
-        442 |
-        443 | class str(Sequence[str]):
-            |       ^^^
-        444 |     @overload
-        445 |     def __new__(cls, object: object = ...) -> Self: ...
-            |
-        info: Source
-         --> /main.py:3:17
-          |
-        2 |             def foo(a: str | None, b):
-        3 |                 a
-          |                 ^
-          |
-
-        info: lint:goto-type-definition: Type definition
-           --> stdlib/types.pyi:677:11
-            |
-        675 | if sys.version_info >= (3, 10):
-        676 |     @final
-        677 |     class NoneType:
-            |           ^^^^^^^^
-        678 |         def __bool__(self) -> Literal[False]: ...
-            |
-        info: Source
-         --> /main.py:3:17
-          |
-        2 |             def foo(a: str | None, b):
-        3 |                 a
-          |                 ^
-          |
-        ");
-    }
-
-    fn goto_test(source: &str) -> GotoTest {
-        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");
-
-        let insta_settings_guard = insta_settings.bind_to_scope();
-
-        GotoTest {
-            db,
-            cursor_offset: TextSize::try_from(cursor_offset)
-                .expect("source to be smaller than 4GB"),
-            file,
-            _insta_settings_guard: insta_settings_guard,
-        }
-    }
-
-    struct GotoTest {
-        db: TestDb,
-        cursor_offset: TextSize,
-        file: File,
-        _insta_settings_guard: SettingsBindDropGuard,
-    }
-
-    impl GotoTest {
-        fn write_file(
-            &mut self,
-            path: impl AsRef<SystemPath>,
-            content: &str,
-        ) -> std::io::Result<()> {
-            self.db.write_file(path, content)
-        }
-
-        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 mut buf = String::new();
-
-            let source = targets.range;
-
-            let config = DisplayDiagnosticConfig::default()
-                .color(false)
-                .format(DiagnosticFormat::Full);
-            for target in &*targets {
-                let diag = GotoTypeDefinitionDiagnostic::new(source, target).into_diagnostic();
-                write!(buf, "{}", diag.display(&self.db, &config)).unwrap();
-            }
-
-            buf
-        }
-    }
-
-    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()),
-            }
-        }
-
-        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/lib.rs

@@ -1,263 +0,0 @@
-mod db;
-mod find_node;
-mod goto;
-
-use std::ops::{Deref, DerefMut};
-
-pub use db::Db;
-pub use goto::goto_type_definition;
-use red_knot_python_semantic::types::{
-    Class, ClassBase, ClassLiteralType, FunctionType, InstanceType, IntersectionType,
-    KnownInstanceType, ModuleLiteralType, Type,
-};
-use ruff_db::files::{File, FileRange};
-use ruff_db::source::source_text;
-use ruff_text_size::{Ranged, TextLen, 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)]
-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 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(iter.into_iter().collect())
-    }
-}
-
-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::BoundMethod(method) => method.function(db).navigation_targets(db),
-            Type::FunctionLiteral(function) => function.navigation_targets(db),
-            Type::ModuleLiteral(module) => module.navigation_targets(db),
-            Type::Union(union) => union
-                .iter(db.upcast())
-                .flat_map(|target| target.navigation_targets(db))
-                .collect(),
-            Type::ClassLiteral(class) => class.navigation_targets(db),
-            Type::Instance(instance) => instance.navigation_targets(db),
-            Type::KnownInstance(instance) => instance.navigation_targets(db),
-            Type::SubclassOf(subclass_of_type) => match subclass_of_type.subclass_of() {
-                ClassBase::Class(class) => class.navigation_targets(db),
-                ClassBase::Dynamic(_) => NavigationTargets::empty(),
-            },
-
-            Type::StringLiteral(_)
-            | Type::BooleanLiteral(_)
-            | Type::LiteralString
-            | Type::IntLiteral(_)
-            | Type::BytesLiteral(_)
-            | Type::SliceLiteral(_)
-            | Type::MethodWrapper(_)
-            | Type::WrapperDescriptor(_)
-            | Type::PropertyInstance(_)
-            | Type::Tuple(_) => self.to_meta_type(db.upcast()).navigation_targets(db),
-
-            Type::Intersection(intersection) => intersection.navigation_targets(db),
-
-            Type::Dynamic(_)
-            | Type::Never
-            | Type::Callable(_)
-            | Type::AlwaysTruthy
-            | Type::AlwaysFalsy => NavigationTargets::empty(),
-        }
-    }
-}
-
-impl HasNavigationTargets for FunctionType<'_> {
-    fn navigation_targets(&self, db: &dyn Db) -> NavigationTargets {
-        let function_range = self.focus_range(db.upcast());
-        NavigationTargets::single(NavigationTarget {
-            file: function_range.file(),
-            focus_range: function_range.range(),
-            full_range: self.full_range(db.upcast()).range(),
-        })
-    }
-}
-
-impl HasNavigationTargets for Class<'_> {
-    fn navigation_targets(&self, db: &dyn Db) -> NavigationTargets {
-        let class_range = self.focus_range(db.upcast());
-        NavigationTargets::single(NavigationTarget {
-            file: class_range.file(),
-            focus_range: class_range.range(),
-            full_range: self.full_range(db.upcast()).range(),
-        })
-    }
-}
-
-impl HasNavigationTargets for ClassLiteralType<'_> {
-    fn navigation_targets(&self, db: &dyn Db) -> NavigationTargets {
-        self.class().navigation_targets(db)
-    }
-}
-
-impl HasNavigationTargets for InstanceType<'_> {
-    fn navigation_targets(&self, db: &dyn Db) -> NavigationTargets {
-        self.class().navigation_targets(db)
-    }
-}
-
-impl HasNavigationTargets for ModuleLiteralType<'_> {
-    fn navigation_targets(&self, db: &dyn Db) -> NavigationTargets {
-        let file = self.module(db).file();
-        let source = source_text(db.upcast(), file);
-
-        NavigationTargets::single(NavigationTarget {
-            file,
-            focus_range: TextRange::default(),
-            full_range: TextRange::up_to(source.text_len()),
-        })
-    }
-}
-
-impl HasNavigationTargets for KnownInstanceType<'_> {
-    fn navigation_targets(&self, db: &dyn Db) -> NavigationTargets {
-        match self {
-            KnownInstanceType::TypeVar(var) => {
-                let definition = var.definition(db);
-                let full_range = definition.full_range(db.upcast());
-
-                NavigationTargets::single(NavigationTarget {
-                    file: full_range.file(),
-                    focus_range: definition.focus_range(db.upcast()).range(),
-                    full_range: full_range.range(),
-                })
-            }
-
-            // TODO: Track the definition of `KnownInstance` and navigate to their definition.
-            _ => NavigationTargets::empty(),
-        }
-    }
-}
-
-impl HasNavigationTargets for IntersectionType<'_> {
-    fn navigation_targets(&self, db: &dyn Db) -> NavigationTargets {
-        // Only consider the positive elements because the negative elements are mainly from narrowing constraints.
-        let mut targets = self
-            .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),
-        }
-    }
-}

crates/red_knot_project/Cargo.toml

@@ -17,7 +17,6 @@ ruff_db = { workspace = true, features = ["cache", "serde"] }
 ruff_macros = { workspace = true }
 ruff_python_ast = { workspace = true, features = ["serde"] }
 ruff_text_size = { workspace = true }
-red_knot_ide = { workspace = true }
 red_knot_python_semantic = { workspace = true, features = ["serde"] }
 red_knot_vendored = { workspace = true }
 

crates/red_knot_project/src/combine.rs

@@ -1,6 +1,6 @@
 use std::{collections::HashMap, hash::BuildHasher};
 
-use red_knot_python_semantic::{PythonPath, PythonPlatform};
+use red_knot_python_semantic::{PythonPlatform, SitePackages};
 use ruff_db::system::SystemPathBuf;
 use ruff_python_ast::PythonVersion;
 
@@ -43,7 +43,7 @@ use ruff_python_ast::PythonVersion;
 /// resolved extra search path of `["b", "c", "a"]`, which means `a` will be tried last.
 ///
 /// There's an argument here that the user should be able to specify the order of the paths,
-/// because only then is the user in full control of where to insert the path when specifying `extra-paths`
+/// because only then is the user in full control of where to insert the path when specyifing `extra-paths`
 /// in multiple sources.
 ///
 /// ## Macro
@@ -128,7 +128,7 @@ macro_rules! impl_noop_combine {
 
 impl_noop_combine!(SystemPathBuf);
 impl_noop_combine!(PythonPlatform);
-impl_noop_combine!(PythonPath);
+impl_noop_combine!(SitePackages);
 impl_noop_combine!(PythonVersion);
 
 // std types

crates/red_knot_project/src/db.rs

@@ -3,7 +3,6 @@ use std::sync::Arc;
 
 use crate::DEFAULT_LINT_REGISTRY;
 use crate::{Project, ProjectMetadata};
-use red_knot_ide::Db as IdeDb;
 use red_knot_python_semantic::lint::{LintRegistry, RuleSelection};
 use red_knot_python_semantic::{Db as SemanticDb, Program};
 use ruff_db::diagnostic::Diagnostic;
@@ -56,12 +55,13 @@ impl ProjectDatabase {
     }
 
     /// Checks all open files in the project and its dependencies.
-    pub fn check(&self) -> Result<Vec<Diagnostic>, Cancelled> {
+    pub fn check(&self) -> Result<Vec<Box<dyn Diagnostic>>, Cancelled> {
         self.with_db(|db| db.project().check(db))
     }
 
-    #[tracing::instrument(level = "debug", skip(self))]
-    pub fn check_file(&self, file: File) -> Result<Vec<Diagnostic>, Cancelled> {
+    pub fn check_file(&self, file: File) -> Result<Vec<Box<dyn Diagnostic>>, Cancelled> {
+        let _span = tracing::debug_span!("check_file", file=%file.path(self)).entered();
+
         self.with_db(|db| self.project().check_file(db, file))
     }
 
@@ -104,19 +104,6 @@ impl Upcast<dyn SourceDb> for ProjectDatabase {
     }
 }
 
-impl Upcast<dyn IdeDb> for ProjectDatabase {
-    fn upcast(&self) -> &(dyn IdeDb + 'static) {
-        self
-    }
-
-    fn upcast_mut(&mut self) -> &mut (dyn IdeDb + 'static) {
-        self
-    }
-}
-
-#[salsa::db]
-impl IdeDb for ProjectDatabase {}
-
 #[salsa::db]
 impl SemanticDb for ProjectDatabase {
     fn is_file_open(&self, file: File) -> bool {

crates/red_knot_project/src/db/changes.rs

@@ -2,20 +2,20 @@ use crate::db::{Db, ProjectDatabase};
 use crate::metadata::options::Options;
 use crate::watch::{ChangeEvent, CreatedKind, DeletedKind};
 use crate::{Project, ProjectMetadata};
-use std::collections::BTreeSet;
 
-use crate::walk::ProjectFilesWalker;
 use red_knot_python_semantic::Program;
-use ruff_db::files::{File, Files};
+use ruff_db::files::{system_path_to_file, File, Files};
+use ruff_db::system::walk_directory::WalkState;
 use ruff_db::system::SystemPath;
 use ruff_db::Db as _;
+use ruff_python_ast::PySourceType;
 use rustc_hash::FxHashSet;
 
 impl ProjectDatabase {
     #[tracing::instrument(level = "debug", skip(self, changes, cli_options))]
     pub fn apply_changes(&mut self, changes: Vec<ChangeEvent>, cli_options: Option<&Options>) {
         let mut project = self.project();
-        let project_root = project.root(self).to_path_buf();
+        let project_path = project.root(self).to_path_buf();
         let program = Program::get(self);
         let custom_stdlib_versions_path = program
             .custom_stdlib_search_path(self)
@@ -30,7 +30,7 @@ impl ProjectDatabase {
 
         // Deduplicate the `sync` calls. Many file watchers emit multiple events for the same path.
         let mut synced_files = FxHashSet::default();
-        let mut sync_recursively = BTreeSet::default();
+        let mut synced_recursively = FxHashSet::default();
 
         let mut sync_path = |db: &mut ProjectDatabase, path: &SystemPath| {
             if synced_files.insert(path.to_path_buf()) {
@@ -38,9 +38,13 @@ impl ProjectDatabase {
             }
         };
 
-        for change in changes {
-            tracing::trace!("Handle change: {:?}", change);
+        let mut sync_recursively = |db: &mut ProjectDatabase, path: &SystemPath| {
+            if synced_recursively.insert(path.to_path_buf()) {
+                Files::sync_recursively(db, path);
+            }
+        };
 
+        for change in changes {
             if let Some(path) = change.system_path() {
                 if matches!(
                     path.file_name(),
@@ -66,27 +70,16 @@ impl ProjectDatabase {
                     match kind {
                         CreatedKind::File => sync_path(self, &path),
                         CreatedKind::Directory | CreatedKind::Any => {
-                            sync_recursively.insert(path.clone());
+                            sync_recursively(self, &path);
                         }
                     }
 
-                    // Unlike other files, it's not only important to update the status of existing
-                    // and known `File`s (`sync_recursively`), it's also important to discover new files
-                    // that were added in the project's root (or any of the paths included for checking).
-                    //
-                    // This is important because `Project::check` iterates over all included files.
-                    // The code below walks the `added_paths` and adds all files that
-                    // should be included in the project. We can skip this check for
-                    // paths that aren't part of the project or shouldn't be included
-                    // when checking the project.
-                    if project.is_path_included(self, &path) {
-                        if self.system().is_file(&path) {
-                            // Add the parent directory because `walkdir` always visits explicitly passed files
-                            // even if they match an exclude filter.
-                            added_paths.insert(path.parent().unwrap().to_path_buf());
-                        } else {
-                            added_paths.insert(path);
-                        }
+                    if self.system().is_file(&path) {
+                        // Add the parent directory because `walkdir` always visits explicitly passed files
+                        // even if they match an exclude filter.
+                        added_paths.insert(path.parent().unwrap().to_path_buf());
+                    } else {
+                        added_paths.insert(path);
                     }
                 }
 
@@ -110,7 +103,7 @@ impl ProjectDatabase {
                             project.remove_file(self, file);
                         }
                     } else {
-                        sync_recursively.insert(path.clone());
+                        sync_recursively(self, &path);
 
                         if custom_stdlib_versions_path
                             .as_ref()
@@ -119,19 +112,11 @@ impl ProjectDatabase {
                             custom_stdlib_change = true;
                         }
 
-                        if project.is_path_included(self, &path) || path == project_root {
-                            // TODO: Shouldn't it be enough to simply traverse the project files and remove all
-                            // that start with the given path?
-                            tracing::debug!(
-                                "Reload project because of a path that could have been a directory."
-                            );
-
-                            // Perform a full-reload in case the deleted directory contained the pyproject.toml.
-                            // We may want to make this more clever in the future, to e.g. iterate over the
-                            // indexed files and remove the once that start with the same path, unless
-                            // the deleted path is the project configuration.
-                            project_changed = true;
-                        }
+                        // Perform a full-reload in case the deleted directory contained the pyproject.toml.
+                        // We may want to make this more clever in the future, to e.g. iterate over the
+                        // indexed files and remove the once that start with the same path, unless
+                        // the deleted path is the project configuration.
+                        project_changed = true;
                     }
                 }
 
@@ -148,29 +133,13 @@ impl ProjectDatabase {
                 ChangeEvent::Rescan => {
                     project_changed = true;
                     Files::sync_all(self);
-                    sync_recursively.clear();
                     break;
                 }
             }
         }
 
-        let sync_recursively = sync_recursively.into_iter();
-        let mut last = None;
-
-        for path in sync_recursively {
-            // Avoid re-syncing paths that are sub-paths of each other.
-            if let Some(last) = &last {
-                if path.starts_with(last) {
-                    continue;
-                }
-            }
-
-            Files::sync_recursively(self, &path);
-            last = Some(path);
-        }
-
         if project_changed {
-            match ProjectMetadata::discover(&project_root, self.system()) {
+            match ProjectMetadata::discover(&project_path, self.system()) {
                 Ok(mut metadata) => {
                     if let Some(cli_options) = cli_options {
                         metadata.apply_cli_options(cli_options.clone());
@@ -217,24 +186,50 @@ impl ProjectDatabase {
             }
         }
 
-        let diagnostics = if let Some(walker) = ProjectFilesWalker::incremental(self, added_paths) {
-            // Use directory walking to discover newly added files.
-            let (files, diagnostics) = walker.collect_vec(self);
+        let mut added_paths = added_paths.into_iter();
 
-            for file in files {
-                project.add_file(self, file);
+        // Use directory walking to discover newly added files.
+        if let Some(path) = added_paths.next() {
+            let mut walker = self.system().walk_directory(&path);
+
+            for extra_path in added_paths {
+                walker = walker.add(&extra_path);
             }
 
-            diagnostics
-        } else {
-            Vec::new()
-        };
+            let added_paths = std::sync::Mutex::new(Vec::default());
 
-        // Note: We simply replace all IO related diagnostics here. This isn't ideal, because
-        // it removes IO errors that may still be relevant. However, tracking IO errors correctly
-        // across revisions doesn't feel essential, considering that they're rare. However, we could
-        // implement a `BTreeMap` or similar and only prune the diagnostics from paths that we've
-        // re-scanned (or that were removed etc).
-        project.replace_index_diagnostics(self, diagnostics);
+            walker.run(|| {
+                Box::new(|entry| {
+                    let Ok(entry) = entry else {
+                        return WalkState::Continue;
+                    };
+
+                    if !entry.file_type().is_file() {
+                        return WalkState::Continue;
+                    }
+
+                    if entry
+                        .path()
+                        .extension()
+                        .and_then(PySourceType::try_from_extension)
+                        .is_some()
+                    {
+                        let mut paths = added_paths.lock().unwrap();
+
+                        paths.push(entry.into_path());
+                    }
+
+                    WalkState::Continue
+                })
+            });
+
+            for path in added_paths.into_inner().unwrap() {
+                let file = system_path_to_file(self, &path);
+
+                if let Ok(file) = file {
+                    project.add_file(self, file);
+                }
+            }
+        }
     }
 }

crates/red_knot_project/src/files.rs

@@ -8,7 +8,10 @@ use salsa::Setter;
 use ruff_db::files::File;
 
 use crate::db::Db;
-use crate::{IOErrorDiagnostic, Project};
+use crate::Project;
+
+/// Cheap cloneable hash set of files.
+type FileSet = Arc<FxHashSet<File>>;
 
 /// The indexed files of a project.
 ///
@@ -32,9 +35,9 @@ impl IndexedFiles {
         }
     }
 
-    fn indexed(inner: Arc<IndexedInner>) -> Self {
+    fn indexed(files: FileSet) -> Self {
         Self {
-            state: std::sync::Mutex::new(State::Indexed(inner)),
+            state: std::sync::Mutex::new(State::Indexed(files)),
         }
     }
 
@@ -43,8 +46,8 @@ impl IndexedFiles {
 
         match &*state {
             State::Lazy => Index::Lazy(LazyFiles { files: state }),
-            State::Indexed(inner) => Index::Indexed(Indexed {
-                inner: Arc::clone(inner),
+            State::Indexed(files) => Index::Indexed(Indexed {
+                files: Arc::clone(files),
                 _lifetime: PhantomData,
             }),
         }
@@ -91,7 +94,7 @@ impl IndexedFiles {
         Some(IndexedMut {
             db: Some(db),
             project,
-            indexed,
+            files: indexed,
             did_change: false,
         })
     }
@@ -109,7 +112,7 @@ enum State {
     Lazy,
 
     /// The files are indexed. Stores the known files of a package.
-    Indexed(Arc<IndexedInner>),
+    Indexed(FileSet),
 }
 
 pub(super) enum Index<'db> {
@@ -126,48 +129,32 @@ pub(super) struct LazyFiles<'db> {
 
 impl<'db> LazyFiles<'db> {
     /// Sets the indexed files of a package to `files`.
-    pub(super) fn set(
-        mut self,
-        files: FxHashSet<File>,
-        diagnostics: Vec<IOErrorDiagnostic>,
-    ) -> Indexed<'db> {
+    pub(super) fn set(mut self, files: FxHashSet<File>) -> Indexed<'db> {
         let files = Indexed {
-            inner: Arc::new(IndexedInner { files, diagnostics }),
+            files: Arc::new(files),
             _lifetime: PhantomData,
         };
-        *self.files = State::Indexed(Arc::clone(&files.inner));
+        *self.files = State::Indexed(Arc::clone(&files.files));
         files
     }
 }
 
-/// The indexed files of the project.
+/// The indexed files of a package.
 ///
 /// Note: This type is intentionally non-cloneable. Making it cloneable requires
 /// revisiting the locking behavior in [`IndexedFiles::indexed_mut`].
-#[derive(Debug)]
+#[derive(Debug, PartialEq, Eq)]
 pub struct Indexed<'db> {
-    inner: Arc<IndexedInner>,
+    files: FileSet,
     // Preserve the lifetime of `PackageFiles`.
     _lifetime: PhantomData<&'db ()>,
 }
 
-#[derive(Debug)]
-struct IndexedInner {
-    files: FxHashSet<File>,
-    diagnostics: Vec<IOErrorDiagnostic>,
-}
-
-impl Indexed<'_> {
-    pub(super) fn diagnostics(&self) -> &[IOErrorDiagnostic] {
-        &self.inner.diagnostics
-    }
-}
-
 impl Deref for Indexed<'_> {
     type Target = FxHashSet<File>;
 
     fn deref(&self) -> &Self::Target {
-        &self.inner.files
+        &self.files
     }
 }
 
@@ -178,7 +165,7 @@ impl<'a> IntoIterator for &'a Indexed<'_> {
     type IntoIter = IndexedIter<'a>;
 
     fn into_iter(self) -> Self::IntoIter {
-        self.inner.files.iter().copied()
+        self.files.iter().copied()
     }
 }
 
@@ -189,13 +176,13 @@ impl<'a> IntoIterator for &'a Indexed<'_> {
 pub(super) struct IndexedMut<'db> {
     db: Option<&'db mut dyn Db>,
     project: Project,
-    indexed: Arc<IndexedInner>,
+    files: FileSet,
     did_change: bool,
 }
 
 impl IndexedMut<'_> {
     pub(super) fn insert(&mut self, file: File) -> bool {
-        if self.inner_mut().files.insert(file) {
+        if self.files_mut().insert(file) {
             self.did_change = true;
             true
         } else {
@@ -204,7 +191,7 @@ impl IndexedMut<'_> {
     }
 
     pub(super) fn remove(&mut self, file: File) -> bool {
-        if self.inner_mut().files.remove(&file) {
+        if self.files_mut().remove(&file) {
             self.did_change = true;
             true
         } else {
@@ -212,13 +199,8 @@ impl IndexedMut<'_> {
         }
     }
 
-    pub(super) fn set_diagnostics(&mut self, diagnostics: Vec<IOErrorDiagnostic>) {
-        self.inner_mut().diagnostics = diagnostics;
-    }
-
-    fn inner_mut(&mut self) -> &mut IndexedInner {
-        Arc::get_mut(&mut self.indexed)
-            .expect("All references to `FilesSet` should have been dropped")
+    fn files_mut(&mut self) -> &mut FxHashSet<File> {
+        Arc::get_mut(&mut self.files).expect("All references to `FilesSet` to have been dropped")
     }
 
     fn set_impl(&mut self) {
@@ -226,16 +208,16 @@ impl IndexedMut<'_> {
             return;
         };
 
-        let indexed = Arc::clone(&self.indexed);
+        let files = Arc::clone(&self.files);
 
         if self.did_change {
             // If there are changes, set the new file_set to trigger a salsa revision change.
             self.project
                 .set_file_set(db)
-                .to(IndexedFiles::indexed(indexed));
+                .to(IndexedFiles::indexed(files));
         } else {
             // The `indexed_mut` replaced the `state` with Lazy. Restore it back to the indexed state.
-            *self.project.file_set(db).state.lock().unwrap() = State::Indexed(indexed);
+            *self.project.file_set(db).state.lock().unwrap() = State::Indexed(files);
         }
     }
 }
@@ -255,7 +237,7 @@ mod tests {
     use crate::files::Index;
     use crate::ProjectMetadata;
     use ruff_db::files::system_path_to_file;
-    use ruff_db::system::{DbWithWritableSystem as _, SystemPathBuf};
+    use ruff_db::system::{DbWithTestSystem, SystemPathBuf};
     use ruff_python_ast::name::Name;
 
     #[test]
@@ -270,7 +252,7 @@ mod tests {
         let file = system_path_to_file(&db, "test.py").unwrap();
 
         let files = match project.file_set(&db).get() {
-            Index::Lazy(lazy) => lazy.set(FxHashSet::from_iter([file]), Vec::new()),
+            Index::Lazy(lazy) => lazy.set(FxHashSet::from_iter([file])),
             Index::Indexed(files) => files,
         };
 

crates/red_knot_project/src/lib.rs

@@ -1,7 +1,6 @@
 #![allow(clippy::ref_option)]
 
 use crate::metadata::options::OptionDiagnostic;
-use crate::walk::{ProjectFilesFilter, ProjectFilesWalker};
 pub use db::{Db, ProjectDatabase};
 use files::{Index, Indexed, IndexedFiles};
 use metadata::settings::Settings;
@@ -9,25 +8,24 @@ pub use metadata::{ProjectDiscoveryError, ProjectMetadata};
 use red_knot_python_semantic::lint::{LintRegistry, LintRegistryBuilder, RuleSelection};
 use red_knot_python_semantic::register_lints;
 use red_knot_python_semantic::types::check_types;
-use ruff_db::diagnostic::{
-    create_parse_diagnostic, Annotation, Diagnostic, DiagnosticId, Severity, Span,
-};
-use ruff_db::files::File;
+use ruff_db::diagnostic::{Diagnostic, DiagnosticId, ParseDiagnostic, Severity, Span};
+use ruff_db::files::{system_path_to_file, File};
 use ruff_db::parsed::parsed_module;
 use ruff_db::source::{source_text, SourceTextError};
-use ruff_db::system::{SystemPath, SystemPathBuf};
-use rustc_hash::FxHashSet;
+use ruff_db::system::walk_directory::WalkState;
+use ruff_db::system::{FileType, SystemPath};
+use ruff_python_ast::PySourceType;
+use rustc_hash::{FxBuildHasher, FxHashSet};
 use salsa::Durability;
 use salsa::Setter;
+use std::borrow::Cow;
 use std::sync::Arc;
-use thiserror::Error;
 
 pub mod combine;
 
 mod db;
 mod files;
 pub mod metadata;
-mod walk;
 pub mod watch;
 
 pub static DEFAULT_LINT_REGISTRY: std::sync::LazyLock<LintRegistry> =
@@ -73,30 +71,6 @@ pub struct Project {
     #[return_ref]
     pub settings: Settings,
 
-    /// The paths that should be included when checking this project.
-    ///
-    /// The default (when this list is empty) is to include all files in the project root
-    /// (that satisfy the configured include and exclude patterns).
-    /// However, it's sometimes desired to only check a subset of the project, e.g. to see
-    /// the diagnostics for a single file or a folder.
-    ///
-    /// This list gets initialized by the paths passed to `knot check <paths>`
-    ///
-    /// ## How is this different from `open_files`?
-    ///
-    /// The `included_paths` is closely related to `open_files`. The only difference is that
-    /// `open_files` is already a resolved set of files whereas `included_paths` is only a list of paths
-    /// that are resolved to files by indexing them. The other difference is that
-    /// new files added to any directory in `included_paths` will be indexed and added to the project
-    /// whereas `open_files` needs to be updated manually (e.g. by the IDE).
-    ///
-    /// In short, `open_files` is cheaper in contexts where the set of files is known, like
-    /// in an IDE when the user only wants to check the open tabs. This could be modeled
-    /// with `included_paths` too but it would require an explicit walk dir step that's simply unnecessary.
-    #[default]
-    #[return_ref]
-    included_paths_list: Vec<SystemPathBuf>,
-
     /// Diagnostics that were generated when resolving the project settings.
     #[return_ref]
     settings_diagnostics: Vec<OptionDiagnostic>,
@@ -132,16 +106,6 @@ impl Project {
         self.settings(db).to_rules()
     }
 
-    /// Returns `true` if `path` is both part of the project and included (see `included_paths_list`).
-    ///
-    /// Unlike [Self::files], this method does not respect `.gitignore` files. It only checks
-    /// the project's include and exclude settings as well as the paths that were passed to `knot check <paths>`.
-    /// This means, that this method is an over-approximation of `Self::files` and may return `true` for paths
-    /// that won't be included when checking the project because they're ignored in a `.gitignore` file.
-    pub fn is_path_included(self, db: &dyn Db, path: &SystemPath) -> bool {
-        ProjectFilesFilter::from_project(db, self).is_included(path)
-    }
-
     pub fn reload(self, db: &mut dyn Db, metadata: ProjectMetadata) {
         tracing::debug!("Reloading project");
         assert_eq!(self.root(db), metadata.root());
@@ -164,27 +128,17 @@ impl Project {
     }
 
     /// Checks all open files in the project and its dependencies.
-    pub(crate) fn check(self, db: &ProjectDatabase) -> Vec<Diagnostic> {
+    pub(crate) fn check(self, db: &ProjectDatabase) -> Vec<Box<dyn Diagnostic>> {
         let project_span = tracing::debug_span!("Project::check");
         let _span = project_span.enter();
 
         tracing::debug!("Checking project '{name}'", name = self.name(db));
 
-        let mut diagnostics: Vec<Diagnostic> = Vec::new();
-        diagnostics.extend(
-            self.settings_diagnostics(db)
-                .iter()
-                .map(OptionDiagnostic::to_diagnostic),
-        );
-
-        let files = ProjectFiles::new(db, self);
-
-        diagnostics.extend(
-            files
-                .diagnostics()
-                .iter()
-                .map(IOErrorDiagnostic::to_diagnostic),
-        );
+        let mut diagnostics: Vec<Box<dyn Diagnostic>> = Vec::new();
+        diagnostics.extend(self.settings_diagnostics(db).iter().map(|diagnostic| {
+            let diagnostic: Box<dyn Diagnostic> = Box::new(diagnostic.clone());
+            diagnostic
+        }));
 
         let result = Arc::new(std::sync::Mutex::new(diagnostics));
         let inner_result = Arc::clone(&result);
@@ -193,14 +147,14 @@ impl Project {
         let project_span = project_span.clone();
 
         rayon::scope(move |scope| {
+            let files = ProjectFiles::new(&db, self);
             for file in &files {
                 let result = inner_result.clone();
                 let db = db.clone();
                 let project_span = project_span.clone();
 
                 scope.spawn(move |_| {
-                    let check_file_span =
-                        tracing::debug_span!(parent: &project_span, "check_file", ?file);
+                    let check_file_span = tracing::debug_span!(parent: &project_span, "check_file", file=%file.path(&db));
                     let _entered = check_file_span.entered();
 
                     let file_diagnostics = check_file_impl(&db, file);
@@ -212,11 +166,14 @@ impl Project {
         Arc::into_inner(result).unwrap().into_inner().unwrap()
     }
 
-    pub(crate) fn check_file(self, db: &dyn Db, file: File) -> Vec<Diagnostic> {
+    pub(crate) fn check_file(self, db: &dyn Db, file: File) -> Vec<Box<dyn Diagnostic>> {
         let mut file_diagnostics: Vec<_> = self
             .settings_diagnostics(db)
             .iter()
-            .map(OptionDiagnostic::to_diagnostic)
+            .map(|diagnostic| {
+                let diagnostic: Box<dyn Diagnostic> = Box::new(diagnostic.clone());
+                diagnostic
+            })
             .collect();
 
         let check_diagnostics = check_file_impl(db, file);
@@ -250,30 +207,6 @@ impl Project {
         removed
     }
 
-    pub fn set_included_paths(self, db: &mut dyn Db, paths: Vec<SystemPathBuf>) {
-        tracing::debug!("Setting included paths: {paths}", paths = paths.len());
-
-        self.set_included_paths_list(db).to(paths);
-        self.reload_files(db);
-    }
-
-    /// Returns the paths that should be checked.
-    ///
-    /// The default is to check the entire project in which case this method returns
-    /// the project root. However, users can specify to only check specific sub-folders or
-    /// even files of a project by using `knot check <paths>`. In that case, this method
-    /// returns the provided absolute paths.
-    ///
-    /// Note: The CLI doesn't prohibit users from specifying paths outside the project root.
-    /// This can be useful to check arbitrary files, but it isn't something we recommend.
-    /// We should try to support this use case but it's okay if there are some limitations around it.
-    fn included_paths_or_root(self, db: &dyn Db) -> &[SystemPathBuf] {
-        match &**self.included_paths_list(db) {
-            [] => std::slice::from_ref(&self.metadata(db).root),
-            paths => paths,
-        }
-    }
-
     /// Returns the open files in the project or `None` if the entire project should be checked.
     pub fn open_files(self, db: &dyn Db) -> Option<&FxHashSet<File>> {
         self.open_fileset(db).as_deref()
@@ -327,7 +260,7 @@ impl Project {
         self.files(db).contains(&file)
     }
 
-    #[tracing::instrument(level = "debug", skip(self, db))]
+    #[tracing::instrument(level = "debug", skip(db))]
     pub fn remove_file(self, db: &mut dyn Db, file: File) {
         tracing::debug!(
             "Removing file `{}` from project `{}`",
@@ -356,17 +289,6 @@ impl Project {
         index.insert(file);
     }
 
-    /// Replaces the diagnostics from indexing the project files with `diagnostics`.
-    ///
-    /// This is a no-op if the project files haven't been indexed yet.
-    pub fn replace_index_diagnostics(self, db: &mut dyn Db, diagnostics: Vec<IOErrorDiagnostic>) {
-        let Some(mut index) = IndexedFiles::indexed_mut(db, self) else {
-            return;
-        };
-
-        index.set_diagnostics(diagnostics);
-    }
-
     /// Returns the files belonging to this project.
     pub fn files(self, db: &dyn Db) -> Indexed<'_> {
         let files = self.file_set(db);
@@ -374,14 +296,12 @@ impl Project {
         let indexed = match files.get() {
             Index::Lazy(vacant) => {
                 let _entered =
-                    tracing::debug_span!("Project::index_files", project = %self.name(db))
+                    tracing::debug_span!("Project::index_files", package = %self.name(db))
                         .entered();
 
-                let walker = ProjectFilesWalker::new(db);
-                let (files, diagnostics) = walker.collect_set(db);
-
-                tracing::info!("Indexed {} file(s)", files.len());
-                vacant.set(files, diagnostics)
+                let files = discover_project_files(db, self);
+                tracing::info!("Found {} files in project `{}`", files.len(), self.name(db));
+                vacant.set(files)
             }
             Index::Indexed(indexed) => indexed,
         };
@@ -399,36 +319,34 @@ impl Project {
     }
 }
 
-fn check_file_impl(db: &dyn Db, file: File) -> Vec<Diagnostic> {
-    let mut diagnostics: Vec<Diagnostic> = Vec::new();
+fn check_file_impl(db: &dyn Db, file: File) -> Vec<Box<dyn Diagnostic>> {
+    let mut diagnostics: Vec<Box<dyn Diagnostic>> = Vec::new();
 
     // Abort checking if there are IO errors.
     let source = source_text(db.upcast(), file);
 
     if let Some(read_error) = source.read_error() {
-        diagnostics.push(
-            IOErrorDiagnostic {
-                file: Some(file),
-                error: read_error.clone().into(),
-            }
-            .to_diagnostic(),
-        );
+        diagnostics.push(Box::new(IOErrorDiagnostic {
+            file,
+            error: read_error.clone(),
+        }));
         return diagnostics;
     }
 
     let parsed = parsed_module(db.upcast(), file);
-    diagnostics.extend(
-        parsed
-            .errors()
-            .iter()
-            .map(|error| create_parse_diagnostic(file, error)),
-    );
+    diagnostics.extend(parsed.errors().iter().map(|error| {
+        let diagnostic: Box<dyn Diagnostic> = Box::new(ParseDiagnostic::new(file, error.clone()));
+        diagnostic
+    }));
 
-    diagnostics.extend(check_types(db.upcast(), file).into_iter().cloned());
+    diagnostics.extend(check_types(db.upcast(), file).iter().map(|diagnostic| {
+        let boxed: Box<dyn Diagnostic> = Box::new(diagnostic.clone());
+        boxed
+    }));
 
     diagnostics.sort_unstable_by_key(|diagnostic| {
         diagnostic
-            .primary_span()
+            .span()
             .and_then(|span| span.range())
             .unwrap_or_default()
             .start()
@@ -437,6 +355,53 @@ fn check_file_impl(db: &dyn Db, file: File) -> Vec<Diagnostic> {
     diagnostics
 }
 
+fn discover_project_files(db: &dyn Db, project: Project) -> FxHashSet<File> {
+    let paths = std::sync::Mutex::new(Vec::new());
+
+    db.system().walk_directory(project.root(db)).run(|| {
+        Box::new(|entry| {
+            match entry {
+                Ok(entry) => {
+                    // Skip over any non python files to avoid creating too many entries in `Files`.
+                    match entry.file_type() {
+                        FileType::File => {
+                            if entry
+                                .path()
+                                .extension()
+                                .and_then(PySourceType::try_from_extension)
+                                .is_some()
+                            {
+                                let mut paths = paths.lock().unwrap();
+                                paths.push(entry.into_path());
+                            }
+                        }
+                        FileType::Directory | FileType::Symlink => {}
+                    }
+                }
+                Err(error) => {
+                    // TODO Handle error
+                    tracing::error!("Failed to walk path: {error}");
+                }
+            }
+
+            WalkState::Continue
+        })
+    });
+
+    let paths = paths.into_inner().unwrap();
+    let mut files = FxHashSet::with_capacity_and_hasher(paths.len(), FxBuildHasher);
+
+    for path in paths {
+        // If this returns `None`, then the file was deleted between the `walk_directory` call and now.
+        // We can ignore this.
+        if let Ok(file) = system_path_to_file(db.upcast(), &path) {
+            files.insert(file);
+        }
+    }
+
+    files
+}
+
 #[derive(Debug)]
 enum ProjectFiles<'a> {
     OpenFiles(&'a FxHashSet<File>),
@@ -451,13 +416,6 @@ impl<'a> ProjectFiles<'a> {
             ProjectFiles::Indexed(project.files(db))
         }
     }
-
-    fn diagnostics(&self) -> &[IOErrorDiagnostic] {
-        match self {
-            ProjectFiles::OpenFiles(_) => &[],
-            ProjectFiles::Indexed(indexed) => indexed.diagnostics(),
-        }
-    }
 }
 
 impl<'a> IntoIterator for &'a ProjectFiles<'a> {
@@ -490,29 +448,28 @@ impl Iterator for ProjectFilesIter<'_> {
     }
 }
 
-#[derive(Debug, Clone)]
+#[derive(Debug)]
 pub struct IOErrorDiagnostic {
-    file: Option<File>,
-    error: IOErrorKind,
+    file: File,
+    error: SourceTextError,
 }
 
-impl IOErrorDiagnostic {
-    fn to_diagnostic(&self) -> Diagnostic {
-        let mut diag = Diagnostic::new(DiagnosticId::Io, Severity::Error, &self.error);
-        if let Some(file) = self.file {
-            diag.annotate(Annotation::primary(Span::from(file)));
-        }
-        diag
+impl Diagnostic for IOErrorDiagnostic {
+    fn id(&self) -> DiagnosticId {
+        DiagnosticId::Io
     }
-}
 
-#[derive(Error, Debug, Clone)]
-enum IOErrorKind {
-    #[error(transparent)]
-    Walk(#[from] walk::WalkError),
+    fn message(&self) -> Cow<str> {
+        self.error.to_string().into()
+    }
 
-    #[error(transparent)]
-    SourceText(#[from] SourceTextError),
+    fn span(&self) -> Option<Span> {
+        Some(Span::from(self.file))
+    }
+
+    fn severity(&self) -> Severity {
+        Severity::Error
+    }
 }
 
 #[cfg(test)]
@@ -520,9 +477,10 @@ mod tests {
     use crate::db::tests::TestDb;
     use crate::{check_file_impl, ProjectMetadata};
     use red_knot_python_semantic::types::check_types;
+    use ruff_db::diagnostic::Diagnostic;
     use ruff_db::files::system_path_to_file;
     use ruff_db::source::source_text;
-    use ruff_db::system::{DbWithTestSystem, DbWithWritableSystem as _, SystemPath, SystemPathBuf};
+    use ruff_db::system::{DbWithTestSystem, SystemPath, SystemPathBuf};
     use ruff_db::testing::assert_function_query_was_not_run;
     use ruff_python_ast::name::Name;
 
@@ -543,7 +501,7 @@ mod tests {
         assert_eq!(
             check_file_impl(&db, file)
                 .into_iter()
-                .map(|diagnostic| diagnostic.primary_message().to_string())
+                .map(|diagnostic| diagnostic.message().into_owned())
                 .collect::<Vec<_>>(),
             vec!["Failed to read file: No such file or directory".to_string()]
         );
@@ -559,7 +517,7 @@ mod tests {
         assert_eq!(
             check_file_impl(&db, file)
                 .into_iter()
-                .map(|diagnostic| diagnostic.primary_message().to_string())
+                .map(|diagnostic| diagnostic.message().into_owned())
                 .collect::<Vec<_>>(),
             vec![] as Vec<String>
         );

crates/red_knot_project/src/metadata.rs

@@ -64,7 +64,7 @@ impl ProjectMetadata {
     }
 
     /// Loads a project from a set of options with an optional pyproject-project table.
-    pub fn from_options(
+    pub(crate) fn from_options(
         mut options: Options,
         root: SystemPathBuf,
         project: Option<&Project>,
@@ -77,10 +77,10 @@ impl ProjectMetadata {
         // If the `options` don't specify a python version but the `project.requires-python` field is set,
         // use that as a lower bound instead.
         if let Some(project) = project {
-            if options
+            if !options
                 .environment
                 .as_ref()
-                .is_none_or(|env| env.python_version.is_none())
+                .is_some_and(|env| env.python_version.is_some())
             {
                 if let Some(requires_python) = project.resolve_requires_python_lower_bound()? {
                     let mut environment = options.environment.unwrap_or_default();
@@ -321,7 +321,7 @@ mod tests {
 
         system
             .memory_file_system()
-            .write_files_all([(root.join("foo.py"), ""), (root.join("bar.py"), "")])
+            .write_files([(root.join("foo.py"), ""), (root.join("bar.py"), "")])
             .context("Failed to write files")?;
 
         let project =
@@ -349,7 +349,7 @@ mod tests {
 
         system
             .memory_file_system()
-            .write_files_all([
+            .write_files([
                 (
                     root.join("pyproject.toml"),
                     r#"
@@ -393,7 +393,7 @@ mod tests {
 
         system
             .memory_file_system()
-            .write_files_all([
+            .write_files([
                 (
                     root.join("pyproject.toml"),
                     r#"
@@ -432,7 +432,7 @@ expected `.`, `]`
 
         system
             .memory_file_system()
-            .write_files_all([
+            .write_files([
                 (
                     root.join("pyproject.toml"),
                     r#"
@@ -482,7 +482,7 @@ expected `.`, `]`
 
         system
             .memory_file_system()
-            .write_files_all([
+            .write_files([
                 (
                     root.join("pyproject.toml"),
                     r#"
@@ -532,7 +532,7 @@ expected `.`, `]`
 
         system
             .memory_file_system()
-            .write_files_all([
+            .write_files([
                 (
                     root.join("pyproject.toml"),
                     r#"
@@ -572,7 +572,7 @@ expected `.`, `]`
 
         system
             .memory_file_system()
-            .write_files_all([
+            .write_files([
                 (
                     root.join("pyproject.toml"),
                     r#"
@@ -623,7 +623,7 @@ expected `.`, `]`
 
         system
             .memory_file_system()
-            .write_files_all([
+            .write_files([
                 (
                     root.join("pyproject.toml"),
                     r#"
@@ -673,7 +673,7 @@ expected `.`, `]`
 
         system
             .memory_file_system()
-            .write_file_all(
+            .write_file(
                 root.join("pyproject.toml"),
                 r#"
                 [project]
@@ -703,7 +703,7 @@ expected `.`, `]`
 
         system
             .memory_file_system()
-            .write_file_all(
+            .write_file(
                 root.join("pyproject.toml"),
                 r#"
                 [project]
@@ -735,7 +735,7 @@ expected `.`, `]`
 
         system
             .memory_file_system()
-            .write_file_all(
+            .write_file(
                 root.join("pyproject.toml"),
                 r#"
                 [project]
@@ -765,7 +765,7 @@ expected `.`, `]`
 
         system
             .memory_file_system()
-            .write_file_all(
+            .write_file(
                 root.join("pyproject.toml"),
                 r#"
                 [project]
@@ -795,7 +795,7 @@ expected `.`, `]`
 
         system
             .memory_file_system()
-            .write_file_all(
+            .write_file(
                 root.join("pyproject.toml"),
                 r#"
                 [project]
@@ -828,7 +828,7 @@ expected `.`, `]`
 
         system
             .memory_file_system()
-            .write_file_all(
+            .write_file(
                 root.join("pyproject.toml"),
                 r#"
                 [project]
@@ -861,7 +861,7 @@ expected `.`, `]`
 
         system
             .memory_file_system()
-            .write_file_all(
+            .write_file(
                 root.join("pyproject.toml"),
                 r#"
                 [project]
@@ -886,7 +886,7 @@ expected `.`, `]`
 
         system
             .memory_file_system()
-            .write_file_all(
+            .write_file(
                 root.join("pyproject.toml"),
                 r#"
                 [project]
@@ -911,7 +911,7 @@ expected `.`, `]`
 
         system
             .memory_file_system()
-            .write_file_all(
+            .write_file(
                 root.join("pyproject.toml"),
                 r#"
                 [project]

crates/red_knot_project/src/metadata/options.rs

@@ -1,14 +1,15 @@
 use crate::metadata::value::{RangedValue, RelativePathBuf, ValueSource, ValueSourceGuard};
 use crate::Db;
 use red_knot_python_semantic::lint::{GetLintError, Level, LintSource, RuleSelection};
-use red_knot_python_semantic::{ProgramSettings, PythonPath, PythonPlatform, SearchPathSettings};
-use ruff_db::diagnostic::{Annotation, Diagnostic, DiagnosticFormat, DiagnosticId, Severity, Span};
+use red_knot_python_semantic::{ProgramSettings, PythonPlatform, SearchPathSettings, SitePackages};
+use ruff_db::diagnostic::{Diagnostic, DiagnosticId, Severity, Span};
 use ruff_db::files::system_path_to_file;
 use ruff_db::system::{System, SystemPath};
 use ruff_macros::Combine;
 use ruff_python_ast::PythonVersion;
 use rustc_hash::FxHashMap;
 use serde::{Deserialize, Serialize};
+use std::borrow::Cow;
 use std::fmt::Debug;
 use thiserror::Error;
 
@@ -36,19 +37,11 @@ pub struct Options {
 
 impl Options {
     pub(crate) fn from_toml_str(content: &str, source: ValueSource) -> Result<Self, KnotTomlError> {
-        let _guard = ValueSourceGuard::new(source, true);
+        let _guard = ValueSourceGuard::new(source);
         let options = toml::from_str(content)?;
         Ok(options)
     }
 
-    pub fn deserialize_with<'de, D>(source: ValueSource, deserializer: D) -> Result<Self, D::Error>
-    where
-        D: serde::Deserializer<'de>,
-    {
-        let _guard = ValueSourceGuard::new(source, false);
-        Self::deserialize(deserializer)
-    }
-
     pub(crate) fn to_program_settings(
         &self,
         project_root: &SystemPath,
@@ -97,7 +90,7 @@ impl Options {
             .map(|env| {
                 (
                     env.extra_paths.clone(),
-                    env.python.clone(),
+                    env.venv_path.clone(),
                     env.typeshed.clone(),
                 )
             })
@@ -111,16 +104,11 @@ impl Options {
                 .collect(),
             src_roots,
             custom_typeshed: typeshed.map(|path| path.absolute(project_root, system)),
-            python_path: python
-                .map(|python_path| {
-                    PythonPath::from_cli_flag(python_path.absolute(project_root, system))
+            site_packages: python
+                .map(|venv_path| SitePackages::Derived {
+                    venv_path: venv_path.absolute(project_root, system),
                 })
-                .or_else(|| {
-                    std::env::var("VIRTUAL_ENV")
-                        .ok()
-                        .map(PythonPath::from_virtual_env_var)
-                })
-                .unwrap_or_else(|| PythonPath::Discover(project_root.to_path_buf())),
+                .unwrap_or(SitePackages::Known(vec![])),
         }
     }
 
@@ -132,11 +120,6 @@ impl Options {
 
         if let Some(terminal) = self.terminal.as_ref() {
             settings.set_terminal(TerminalSettings {
-                output_format: terminal
-                    .output_format
-                    .as_deref()
-                    .copied()
-                    .unwrap_or_default(),
                 error_on_warning: terminal.error_on_warning.unwrap_or_default(),
             });
         }
@@ -253,14 +236,10 @@ pub struct EnvironmentOptions {
     #[serde(skip_serializing_if = "Option::is_none")]
     pub typeshed: Option<RelativePathBuf>,
 
-    /// Path to the Python installation from which Red Knot resolves type information and third-party dependencies.
-    ///
-    /// 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.
+    // TODO: Rename to python, see https://github.com/astral-sh/ruff/issues/15530
+    /// The path to the user's `site-packages` directory, where third-party packages from ``PyPI`` are installed.
     #[serde(skip_serializing_if = "Option::is_none")]
-    pub python: Option<RelativePathBuf>,
+    pub venv_path: Option<RelativePathBuf>,
 }
 
 #[derive(Debug, Default, Clone, Eq, PartialEq, Combine, Serialize, Deserialize)]
@@ -294,11 +273,6 @@ impl FromIterator<(RangedValue<String>, RangedValue<Level>)> for Rules {
 #[serde(rename_all = "kebab-case", deny_unknown_fields)]
 #[cfg_attr(feature = "schemars", derive(schemars::JsonSchema))]
 pub struct TerminalOptions {
-    /// The format to use for printing diagnostic messages.
-    ///
-    /// Defaults to `full`.
-    #[serde(skip_serializing_if = "Option::is_none")]
-    pub output_format: Option<RangedValue<DiagnosticFormat>>,
     /// Use exit code 1 if there are any warning-level diagnostics.
     ///
     /// Defaults to `false`.
@@ -396,14 +370,22 @@ impl OptionDiagnostic {
     fn with_span(self, span: Option<Span>) -> Self {
         OptionDiagnostic { span, ..self }
     }
+}
 
-    pub(crate) fn to_diagnostic(&self) -> Diagnostic {
-        if let Some(ref span) = self.span {
-            let mut diag = Diagnostic::new(self.id, self.severity, "");
-            diag.annotate(Annotation::primary(span.clone()).message(&self.message));
-            diag
-        } else {
-            Diagnostic::new(self.id, self.severity, &self.message)
-        }
+impl Diagnostic for OptionDiagnostic {
+    fn id(&self) -> DiagnosticId {
+        self.id
+    }
+
+    fn message(&self) -> Cow<str> {
+        Cow::Borrowed(&self.message)
+    }
+
+    fn span(&self) -> Option<Span> {
+        self.span.clone()
+    }
+
+    fn severity(&self) -> Severity {
+        self.severity
     }
 }

crates/red_knot_project/src/metadata/pyproject.rs

@@ -34,7 +34,7 @@ impl PyProject {
         content: &str,
         source: ValueSource,
     ) -> Result<Self, PyProjectError> {
-        let _guard = ValueSourceGuard::new(source, true);
+        let _guard = ValueSourceGuard::new(source);
         toml::from_str(content).map_err(PyProjectError::TomlSyntax)
     }
 }

crates/red_knot_project/src/metadata/settings.rs

@@ -1,7 +1,6 @@
 use std::sync::Arc;
 
 use red_knot_python_semantic::lint::RuleSelection;
-use ruff_db::diagnostic::DiagnosticFormat;
 
 /// The resolved [`super::Options`] for the project.
 ///
@@ -50,6 +49,5 @@ impl Settings {
 
 #[derive(Debug, Clone, PartialEq, Eq, Default)]
 pub struct TerminalSettings {
-    pub output_format: DiagnosticFormat,
     pub error_on_warning: bool,
 }

crates/red_knot_project/src/metadata/value.rs

@@ -19,7 +19,6 @@ pub enum ValueSource {
     /// Ideally, we'd use [`ruff_db::files::File`] but we can't because the database hasn't been
     /// created when loading the configuration.
     File(Arc<SystemPathBuf>),
-
     /// The value comes from a CLI argument, while it's left open if specified using a short argument,
     /// long argument (`--extra-paths`) or `--config key=value`.
     Cli,
@@ -42,18 +41,18 @@ thread_local! {
     /// Use the [`ValueSourceGuard`] to initialize the thread local before calling into any
     /// deserialization code. It ensures that the thread local variable gets cleaned up
     /// once deserialization is done (once the guard gets dropped).
-    static VALUE_SOURCE: RefCell<Option<(ValueSource, bool)>> = const { RefCell::new(None) };
+    static VALUE_SOURCE: RefCell<Option<ValueSource>> = const { RefCell::new(None) };
 }
 
 /// Guard to safely change the [`VALUE_SOURCE`] for the current thread.
 #[must_use]
 pub(super) struct ValueSourceGuard {
-    prev_value: Option<(ValueSource, bool)>,
+    prev_value: Option<ValueSource>,
 }
 
 impl ValueSourceGuard {
-    pub(super) fn new(source: ValueSource, is_toml: bool) -> Self {
-        let prev = VALUE_SOURCE.replace(Some((source, is_toml)));
+    pub(super) fn new(source: ValueSource) -> Self {
+        let prev = VALUE_SOURCE.replace(Some(source));
         Self { prev_value: prev }
     }
 }
@@ -266,24 +265,18 @@ where
     where
         D: Deserializer<'de>,
     {
-        VALUE_SOURCE.with_borrow(|source| {
-            let (source, has_span) = source.clone().unwrap();
+        let spanned: Spanned<T> = Spanned::deserialize(deserializer)?;
+        let span = spanned.span();
+        let range = TextRange::new(
+            TextSize::try_from(span.start).expect("Configuration file to be smaller than 4GB"),
+            TextSize::try_from(span.end).expect("Configuration file to be smaller than 4GB"),
+        );
 
-            if has_span {
-                let spanned: Spanned<T> = Spanned::deserialize(deserializer)?;
-                let span = spanned.span();
-                let range = TextRange::new(
-                    TextSize::try_from(span.start)
-                        .expect("Configuration file to be smaller than 4GB"),
-                    TextSize::try_from(span.end)
-                        .expect("Configuration file to be smaller than 4GB"),
-                );
+        Ok(VALUE_SOURCE.with_borrow(|source| {
+            let source = source.clone().unwrap();
 
-                Ok(Self::with_range(spanned.into_inner(), source, range))
-            } else {
-                Ok(Self::new(T::deserialize(deserializer)?, source))
-            }
-        })
+            Self::with_range(spanned.into_inner(), source, range)
+        }))
     }
 }
 

crates/red_knot_project/src/walk.rs

@@ -1,256 +0,0 @@
-use crate::{Db, IOErrorDiagnostic, IOErrorKind, Project};
-use ruff_db::files::{system_path_to_file, File};
-use ruff_db::system::walk_directory::{ErrorKind, WalkDirectoryBuilder, WalkState};
-use ruff_db::system::{FileType, SystemPath, SystemPathBuf};
-use ruff_python_ast::PySourceType;
-use rustc_hash::{FxBuildHasher, FxHashSet};
-use std::path::PathBuf;
-use thiserror::Error;
-
-/// Filter that decides which files are included in the project.
-///
-/// In the future, this will hold a reference to the `include` and `exclude` pattern.
-///
-/// This struct mainly exists because `dyn Db` isn't `Send` or `Sync`, making it impossible
-/// to access fields from within the walker.
-#[derive(Default, Debug)]
-pub(crate) struct ProjectFilesFilter<'a> {
-    /// The same as [`Project::included_paths_or_root`].
-    included_paths: &'a [SystemPathBuf],
-
-    /// The filter skips checking if the path is in `included_paths` if set to `true`.
-    ///
-    /// Skipping this check is useful when the walker only walks over `included_paths`.
-    skip_included_paths: bool,
-}
-
-impl<'a> ProjectFilesFilter<'a> {
-    pub(crate) fn from_project(db: &'a dyn Db, project: Project) -> Self {
-        Self {
-            included_paths: project.included_paths_or_root(db),
-            skip_included_paths: false,
-        }
-    }
-
-    /// Returns `true` if a file is part of the project and included in the paths to check.
-    ///
-    /// A file is included in the checked files if it is a sub path of the project's root
-    /// (when no CLI path arguments are specified) or if it is a sub path of any path provided on the CLI (`knot check <paths>`) AND:
-    ///
-    /// * It matches a positive `include` pattern and isn't excluded by a later negative `include` pattern.
-    /// * It doesn't match a positive `exclude` pattern or is re-included by a later negative `exclude` pattern.
-    ///
-    /// ## Note
-    ///
-    /// This method may return `true` for files that don't end up being included when walking the
-    /// project tree because it doesn't consider `.gitignore` and other ignore files when deciding
-    /// if a file's included.
-    pub(crate) fn is_included(&self, path: &SystemPath) -> bool {
-        #[derive(Copy, Clone, Debug, PartialEq, Eq, PartialOrd, Ord)]
-        enum CheckPathMatch {
-            /// The path is a partial match of the checked path (it's a sub path)
-            Partial,
-
-            /// The path matches a check path exactly.
-            Full,
-        }
-
-        let m = if self.skip_included_paths {
-            Some(CheckPathMatch::Partial)
-        } else {
-            self.included_paths
-                .iter()
-                .filter_map(|included_path| {
-                    if let Ok(relative_path) = path.strip_prefix(included_path) {
-                        // Exact matches are always included
-                        if relative_path.as_str().is_empty() {
-                            Some(CheckPathMatch::Full)
-                        } else {
-                            Some(CheckPathMatch::Partial)
-                        }
-                    } else {
-                        None
-                    }
-                })
-                .max()
-        };
-
-        match m {
-            None => false,
-            Some(CheckPathMatch::Partial) => {
-                // TODO: For partial matches, only include the file if it is included by the project's include/exclude settings.
-                true
-            }
-            Some(CheckPathMatch::Full) => true,
-        }
-    }
-}
-
-pub(crate) struct ProjectFilesWalker<'a> {
-    walker: WalkDirectoryBuilder,
-
-    filter: ProjectFilesFilter<'a>,
-}
-
-impl<'a> ProjectFilesWalker<'a> {
-    pub(crate) fn new(db: &'a dyn Db) -> Self {
-        let project = db.project();
-
-        let mut filter = ProjectFilesFilter::from_project(db, project);
-        // It's unnecessary to filter on included paths because it only iterates over those to start with.
-        filter.skip_included_paths = true;
-
-        Self::from_paths(db, project.included_paths_or_root(db), filter)
-            .expect("included_paths_or_root to never return an empty iterator")
-    }
-
-    /// Creates a walker for indexing the project files incrementally.
-    ///
-    /// The main difference to a full project walk is that `paths` may contain paths
-    /// that aren't part of the included files.
-    pub(crate) fn incremental<P>(db: &'a dyn Db, paths: impl IntoIterator<Item = P>) -> Option<Self>
-    where
-        P: AsRef<SystemPath>,
-    {
-        let project = db.project();
-
-        let filter = ProjectFilesFilter::from_project(db, project);
-
-        Self::from_paths(db, paths, filter)
-    }
-
-    fn from_paths<P>(
-        db: &'a dyn Db,
-        paths: impl IntoIterator<Item = P>,
-        filter: ProjectFilesFilter<'a>,
-    ) -> Option<Self>
-    where
-        P: AsRef<SystemPath>,
-    {
-        let mut paths = paths.into_iter();
-
-        let mut walker = db.system().walk_directory(paths.next()?.as_ref());
-
-        for path in paths {
-            walker = walker.add(path);
-        }
-
-        Some(Self { walker, filter })
-    }
-
-    /// Walks the project paths and collects the paths of all files that
-    /// are included in the project.
-    pub(crate) fn walk_paths(self) -> (Vec<SystemPathBuf>, Vec<IOErrorDiagnostic>) {
-        let paths = std::sync::Mutex::new(Vec::new());
-        let diagnostics = std::sync::Mutex::new(Vec::new());
-
-        self.walker.run(|| {
-            Box::new(|entry| {
-                match entry {
-                    Ok(entry) => {
-                        if !self.filter.is_included(entry.path()) {
-                            tracing::debug!("Ignoring not-included path: {}", entry.path());
-                            return WalkState::Skip;
-                        }
-
-                        // Skip over any non python files to avoid creating too many entries in `Files`.
-                        match entry.file_type() {
-                            FileType::File => {
-                                if entry
-                                    .path()
-                                    .extension()
-                                    .and_then(PySourceType::try_from_extension)
-                                    .is_some()
-                                {
-                                    let mut paths = paths.lock().unwrap();
-                                    paths.push(entry.into_path());
-                                }
-                            }
-                            FileType::Directory | FileType::Symlink => {}
-                        }
-                    }
-                    Err(error) => match error.kind() {
-                        ErrorKind::Loop { .. } => {
-                            unreachable!("Loops shouldn't be possible without following symlinks.")
-                        }
-                        ErrorKind::Io { path, err } => {
-                            let mut diagnostics = diagnostics.lock().unwrap();
-                            let error = if let Some(path) = path {
-                                WalkError::IOPathError {
-                                    path: path.clone(),
-                                    error: err.to_string(),
-                                }
-                            } else {
-                                WalkError::IOError {
-                                    error: err.to_string(),
-                                }
-                            };
-
-                            diagnostics.push(IOErrorDiagnostic {
-                                file: None,
-                                error: IOErrorKind::Walk(error),
-                            });
-                        }
-                        ErrorKind::NonUtf8Path { path } => {
-                            diagnostics.lock().unwrap().push(IOErrorDiagnostic {
-                                file: None,
-                                error: IOErrorKind::Walk(WalkError::NonUtf8Path {
-                                    path: path.clone(),
-                                }),
-                            });
-                        }
-                    },
-                }
-
-                WalkState::Continue
-            })
-        });
-
-        (
-            paths.into_inner().unwrap(),
-            diagnostics.into_inner().unwrap(),
-        )
-    }
-
-    pub(crate) fn collect_vec(self, db: &dyn Db) -> (Vec<File>, Vec<IOErrorDiagnostic>) {
-        let (paths, diagnostics) = self.walk_paths();
-
-        (
-            paths
-                .into_iter()
-                .filter_map(move |path| {
-                    // If this returns `None`, then the file was deleted between the `walk_directory` call and now.
-                    // We can ignore this.
-                    system_path_to_file(db.upcast(), &path).ok()
-                })
-                .collect(),
-            diagnostics,
-        )
-    }
-
-    pub(crate) fn collect_set(self, db: &dyn Db) -> (FxHashSet<File>, Vec<IOErrorDiagnostic>) {
-        let (paths, diagnostics) = self.walk_paths();
-
-        let mut files = FxHashSet::with_capacity_and_hasher(paths.len(), FxBuildHasher);
-
-        for path in paths {
-            if let Ok(file) = system_path_to_file(db.upcast(), &path) {
-                files.insert(file);
-            }
-        }
-
-        (files, diagnostics)
-    }
-}
-
-#[derive(Error, Debug, Clone)]
-pub(crate) enum WalkError {
-    #[error("`{path}`: {error}")]
-    IOPathError { path: SystemPathBuf, error: String },
-
-    #[error("Failed to walk project directory: {error}")]
-    IOError { error: String },
-
-    #[error("`{path}` is not a valid UTF-8 path")]
-    NonUtf8Path { path: PathBuf },
-}

crates/red_knot_project/src/watch/project_watcher.rs

@@ -6,7 +6,7 @@ use tracing::info;
 use red_knot_python_semantic::system_module_search_paths;
 use ruff_cache::{CacheKey, CacheKeyHasher};
 use ruff_db::system::{SystemPath, SystemPathBuf};
-use ruff_db::Upcast;
+use ruff_db::{Db as _, Upcast};
 
 use crate::db::{Db, ProjectDatabase};
 use crate::watch::Watcher;
@@ -42,9 +42,9 @@ impl ProjectWatcher {
 
     pub fn update(&mut self, db: &ProjectDatabase) {
         let search_paths: Vec<_> = system_module_search_paths(db.upcast()).collect();
-        let project_path = db.project().root(db);
+        let project_path = db.project().root(db).to_path_buf();
 
-        let new_cache_key = Self::compute_cache_key(project_path, &search_paths);
+        let new_cache_key = Self::compute_cache_key(&project_path, &search_paths);
 
         if self.cache_key == Some(new_cache_key) {
             return;
@@ -68,47 +68,41 @@ impl ProjectWatcher {
 
         self.has_errored_paths = false;
 
+        let project_path = db
+            .system()
+            .canonicalize_path(&project_path)
+            .unwrap_or(project_path);
+
         let config_paths = db
             .project()
             .metadata(db)
             .extra_configuration_paths()
             .iter()
-            .map(SystemPathBuf::as_path);
-
-        // Watch both the project root and any paths provided by the user on the CLI (removing any redundant nested paths).
-        // This is necessary to observe changes to files that are outside the project root.
-        // We always need to watch the project root to observe changes to its configuration.
-        let included_paths = ruff_db::system::deduplicate_nested_paths(
-            std::iter::once(project_path).chain(
-                db.project()
-                    .included_paths_list(db)
-                    .iter()
-                    .map(SystemPathBuf::as_path),
-            ),
-        );
+            .cloned();
 
         // Find the non-overlapping module search paths and filter out paths that are already covered by the project.
         // Module search paths are already canonicalized.
         let unique_module_paths = ruff_db::system::deduplicate_nested_paths(
             search_paths
                 .into_iter()
-                .filter(|path| !path.starts_with(project_path)),
-        );
+                .filter(|path| !path.starts_with(&project_path)),
+        )
+        .map(SystemPath::to_path_buf);
 
         // Now add the new paths, first starting with the project path and then
         // adding the library search paths, and finally the paths for configurations.
-        for path in included_paths
+        for path in std::iter::once(project_path)
             .chain(unique_module_paths)
             .chain(config_paths)
         {
             // Log a warning. It's not worth aborting if registering a single folder fails because
             // Ruff otherwise stills works as expected.
-            if let Err(error) = self.watcher.watch(path) {
+            if let Err(error) = self.watcher.watch(&path) {
                 // TODO: Log a user-facing warning.
                 tracing::warn!("Failed to setup watcher for path `{path}`: {error}. You have to restart Ruff after making changes to files under this path or you might see stale results.");
                 self.has_errored_paths = true;
             } else {
-                self.watched_paths.push(path.to_path_buf());
+                self.watched_paths.push(path);
             }
         }
 

crates/red_knot_project/tests/check.rs

@@ -117,7 +117,7 @@ fn run_corpus_tests(pattern: &str) -> anyhow::Result<()> {
         let code = std::fs::read_to_string(source)?;
 
         let mut check_with_file_name = |path: &SystemPath| {
-            memory_fs.write_file_all(path, &code).unwrap();
+            memory_fs.write_file(path, &code).unwrap();
             File::sync_path(&mut db, path);
 
             // this test is only asserting that we can pull every expression type without a panic
@@ -216,17 +216,6 @@ impl SourceOrderVisitor<'_> for PullTypesVisitor<'_> {
                 self.visit_body(&for_stmt.orelse);
                 return;
             }
-            Stmt::With(with_stmt) => {
-                for item in &with_stmt.items {
-                    if let Some(target) = &item.optional_vars {
-                        self.visit_target(target);
-                    }
-                    self.visit_expr(&item.context_expr);
-                }
-
-                self.visit_body(&with_stmt.body);
-                return;
-            }
             Stmt::AnnAssign(_)
             | Stmt::Return(_)
             | Stmt::Delete(_)
@@ -234,6 +223,7 @@ impl SourceOrderVisitor<'_> for PullTypesVisitor<'_> {
             | Stmt::TypeAlias(_)
             | Stmt::While(_)
             | Stmt::If(_)
+            | Stmt::With(_)
             | Stmt::Match(_)
             | Stmt::Raise(_)
             | Stmt::Try(_)
@@ -279,4 +269,18 @@ impl SourceOrderVisitor<'_> for PullTypesVisitor<'_> {
 
 /// Whether or not the .py/.pyi version of this file is expected to fail
 #[rustfmt::skip]
-const KNOWN_FAILURES: &[(&str, bool, bool)] = &[];
+const KNOWN_FAILURES: &[(&str, bool, bool)] = &[
+    // related to circular references in nested functions
+    ("crates/ruff_linter/resources/test/fixtures/flake8_return/RET503.py", false, true),
+    // related to circular references in class definitions
+    ("crates/ruff_linter/resources/test/fixtures/pyflakes/F821_26.py", true, true),
+    ("crates/ruff_linter/resources/test/fixtures/pyflakes/F821_27.py", true, true),
+    ("crates/ruff_linter/resources/test/fixtures/pyflakes/F811_19.py", true, false),
+    ("crates/ruff_linter/resources/test/fixtures/pyupgrade/UP039.py", true, false),
+    // related to circular references in type aliases (salsa cycle panic):
+    ("crates/ruff_python_parser/resources/inline/err/type_alias_invalid_value_expr.py", true, true),
+    ("crates/ruff_linter/resources/test/fixtures/flake8_type_checking/TC008.py", true, true),
+    // related to circular references in f-string annotations (invalid syntax)
+    ("crates/ruff_linter/resources/test/fixtures/pyflakes/F821_15.py", true, true),
+    ("crates/ruff_linter/resources/test/fixtures/pyflakes/F821_14.py", false, true),
+];

crates/red_knot_python_semantic/Cargo.toml

@@ -42,8 +42,6 @@ smallvec = { workspace = true }
 static_assertions = { workspace = true }
 test-case = { workspace = true }
 memchr = { workspace = true }
-strum = { workspace = true}
-strum_macros = { workspace = true}
 
 [dev-dependencies]
 ruff_db = { workspace = true, features = ["testing", "os"] }

crates/red_knot_python_semantic/mdtest.py

@@ -155,7 +155,6 @@ class MDTestRunner:
 
     def watch(self) -> Never:
         self._recompile_tests("Compiling tests...", message_on_success=False)
-        self._run_mdtest()
         self.console.print("[dim]Ready to watch for changes...[/dim]")
 
         for changes in watch(CRATE_ROOT):

crates/red_knot_python_semantic/resources/mdtest/annotations/annotated.md

@@ -29,7 +29,7 @@ It is invalid to parameterize `Annotated` with less than two arguments.
 ```py
 from typing_extensions import Annotated
 
-# error: [invalid-type-form] "`typing.Annotated` requires at least two arguments when used in a type expression"
+# error: [invalid-type-form] "`Annotated` requires at least two arguments when used in an annotation or type expression"
 def _(x: Annotated):
     reveal_type(x)  # revealed: Unknown
 
@@ -39,11 +39,11 @@ def _(flag: bool):
     else:
         X = bool
 
-    # error: [invalid-type-form] "`typing.Annotated` requires at least two arguments when used in a type expression"
+    # error: [invalid-type-form] "`Annotated` requires at least two arguments when used in an annotation or type expression"
     def f(y: X):
         reveal_type(y)  # revealed: Unknown | bool
 
-# error: [invalid-type-form] "`typing.Annotated` requires at least two arguments when used in a type expression"
+# error: [invalid-type-form] "`Annotated` requires at least two arguments when used in an annotation or type expression"
 def _(x: Annotated | bool):
     reveal_type(x)  # revealed: Unknown | bool
 
@@ -73,10 +73,12 @@ Inheriting from `Annotated[T, ...]` is equivalent to inheriting from `T` itself.
 ```py
 from typing_extensions import Annotated
 
+# TODO: False positive
+# error: [invalid-base]
 class C(Annotated[int, "foo"]): ...
 
 # TODO: Should be `tuple[Literal[C], Literal[int], Literal[object]]`
-reveal_type(C.__mro__)  # revealed: tuple[Literal[C], @Todo(Inference of subscript on special form), Literal[object]]
+reveal_type(C.__mro__)  # revealed: tuple[Literal[C], Unknown, Literal[object]]
 ```
 
 ### Not parameterized

crates/red_knot_python_semantic/resources/mdtest/annotations/callable.md

@@ -1,302 +0,0 @@
-# Callable
-
-References:
-
-- <https://typing.readthedocs.io/en/latest/spec/callables.html#callable>
-
-Note that `typing.Callable` is deprecated at runtime, in favour of `collections.abc.Callable` (see:
-<https://docs.python.org/3/library/typing.html#deprecated-aliases>). However, removal of
-`typing.Callable` is not currently planned, and the canonical location of the stub for the symbol in
-typeshed is still `typing.pyi`.
-
-## Invalid forms
-
-The `Callable` special form requires _exactly_ two arguments where the first argument is either a
-parameter type list, parameter specification, `typing.Concatenate`, or `...` and the second argument
-is the return type. Here, we explore various invalid forms.
-
-### Empty
-
-A bare `Callable` without any type arguments:
-
-```py
-from typing import Callable
-
-def _(c: Callable):
-    reveal_type(c)  # revealed: (...) -> Unknown
-```
-
-### Invalid parameter type argument
-
-When it's not a list:
-
-```py
-from typing import Callable
-
-# error: [invalid-type-form] "The first argument to `Callable` must be either a list of types, ParamSpec, Concatenate, or `...`"
-def _(c: Callable[int, str]):
-    reveal_type(c)  # revealed: (...) -> Unknown
-```
-
-Or, when it's a literal type:
-
-```py
-# error: [invalid-type-form] "The first argument to `Callable` must be either a list of types, ParamSpec, Concatenate, or `...`"
-def _(c: Callable[42, str]):
-    reveal_type(c)  # revealed: (...) -> Unknown
-```
-
-Or, when one of the parameter type is invalid in the list:
-
-```py
-# error: [invalid-type-form] "Int literals are not allowed in this context in a type expression"
-# error: [invalid-type-form] "Boolean literals are not allowed in this context in a type expression"
-def _(c: Callable[[int, 42, str, False], None]):
-    # revealed: (int, Unknown, str, Unknown, /) -> None
-    reveal_type(c)
-```
-
-### Missing return type
-
-Using a parameter list:
-
-```py
-from typing import Callable
-
-# error: [invalid-type-form] "Special form `typing.Callable` expected exactly two arguments (parameter types and return type)"
-def _(c: Callable[[int, str]]):
-    reveal_type(c)  # revealed: (...) -> Unknown
-```
-
-Or, an ellipsis:
-
-```py
-# error: [invalid-type-form] "Special form `typing.Callable` expected exactly two arguments (parameter types and return type)"
-def _(c: Callable[...]):
-    reveal_type(c)  # revealed: (...) -> Unknown
-```
-
-Or something else that's invalid in a type expression generally:
-
-```py
-# fmt: off
-
-def _(c: Callable[  # error: [invalid-type-form] "Special form `typing.Callable` expected exactly two arguments (parameter types and return type)"
-            {1, 2}  # error: [invalid-type-form] "The first argument to `Callable` must be either a list of types, ParamSpec, Concatenate, or `...`"
-        ]
-    ):
-    reveal_type(c)  # revealed: (...) -> Unknown
-```
-
-### More than two arguments
-
-We can't reliably infer the callable type if there are more then 2 arguments because we don't know
-which argument corresponds to either the parameters or the return type.
-
-```py
-from typing import Callable
-
-# error: [invalid-type-form] "Special form `typing.Callable` expected exactly two arguments (parameter types and return type)"
-def _(c: Callable[[int], str, str]):
-    reveal_type(c)  # revealed: (...) -> Unknown
-```
-
-### List as the second argument
-
-```py
-from typing import Callable
-
-# fmt: off
-
-def _(c: Callable[
-            int,  # error: [invalid-type-form] "The first argument to `Callable` must be either a list of types, ParamSpec, Concatenate, or `...`"
-            [str]  # error: [invalid-type-form] "List literals are not allowed in this context in a type expression"
-        ]
-    ):
-    reveal_type(c)  # revealed: (...) -> Unknown
-```
-
-### List as both arguments
-
-```py
-from typing import Callable
-
-# error: [invalid-type-form] "List literals are not allowed in this context in a type expression"
-def _(c: Callable[[int], [str]]):
-    reveal_type(c)  # revealed: (int, /) -> Unknown
-```
-
-### Three list arguments
-
-```py
-from typing import Callable
-
-# fmt: off
-
-
-def _(c: Callable[  # error: [invalid-type-form] "Special form `typing.Callable` expected exactly two arguments (parameter types and return type)"
-            [int],
-            [str],  # error: [invalid-type-form] "List literals are not allowed in this context in a type expression"
-            [bytes]  # error: [invalid-type-form] "List literals are not allowed in this context in a type expression"
-        ]
-    ):
-    reveal_type(c)  # revealed: (...) -> Unknown
-```
-
-## Simple
-
-A simple `Callable` with multiple parameters and a return type:
-
-```py
-from typing import Callable
-
-def _(c: Callable[[int, str], int]):
-    reveal_type(c)  # revealed: (int, str, /) -> int
-```
-
-## Union
-
-```py
-from typing import Callable, Union
-
-def _(
-    c: Callable[[Union[int, str]], int] | None,
-    d: None | Callable[[Union[int, str]], int],
-    e: None | Callable[[Union[int, str]], int] | int,
-):
-    reveal_type(c)  # revealed: ((int | str, /) -> int) | None
-    reveal_type(d)  # revealed: None | ((int | str, /) -> int)
-    reveal_type(e)  # revealed: None | ((int | str, /) -> int) | int
-```
-
-## Intersection
-
-```py
-from typing import Callable, Union
-from knot_extensions import Intersection, Not
-
-def _(
-    c: Intersection[Callable[[Union[int, str]], int], int],
-    d: Intersection[int, Callable[[Union[int, str]], int]],
-    e: Intersection[int, Callable[[Union[int, str]], int], str],
-    f: Intersection[Not[Callable[[int, str], Intersection[int, str]]]],
-):
-    reveal_type(c)  # revealed: ((int | str, /) -> int) & int
-    reveal_type(d)  # revealed: int & ((int | str, /) -> int)
-    reveal_type(e)  # revealed: int & ((int | str, /) -> int) & str
-    reveal_type(f)  # revealed: ~((int, str, /) -> int & str)
-```
-
-## Nested
-
-A nested `Callable` as one of the parameter types:
-
-```py
-from typing import Callable
-
-def _(c: Callable[[Callable[[int], str]], int]):
-    reveal_type(c)  # revealed: ((int, /) -> str, /) -> int
-```
-
-And, as the return type:
-
-```py
-def _(c: Callable[[int, str], Callable[[int], int]]):
-    reveal_type(c)  # revealed: (int, str, /) -> (int, /) -> int
-```
-
-## Gradual form
-
-The `Callable` special form supports the use of `...` in place of the list of parameter types. This
-is a [gradual form] indicating that the type is consistent with any input signature:
-
-```py
-from typing import Callable
-
-def gradual_form(c: Callable[..., str]):
-    reveal_type(c)  # revealed: (...) -> str
-```
-
-## Using `typing.Concatenate`
-
-Using `Concatenate` as the first argument to `Callable`:
-
-```py
-from typing_extensions import Callable, Concatenate
-
-def _(c: Callable[Concatenate[int, str, ...], int]):
-    reveal_type(c)  # revealed: (*args: @Todo(todo signature *args), **kwargs: @Todo(todo signature **kwargs)) -> int
-```
-
-And, as one of the parameter types:
-
-```py
-def _(c: Callable[[Concatenate[int, str, ...], int], int]):
-    reveal_type(c)  # revealed: (*args: @Todo(todo signature *args), **kwargs: @Todo(todo signature **kwargs)) -> int
-```
-
-## Using `typing.ParamSpec`
-
-Using a `ParamSpec` in a `Callable` annotation:
-
-```py
-from typing_extensions import Callable
-
-# TODO: Not an error; remove once `ParamSpec` is supported
-# error: [invalid-type-form]
-def _[**P1](c: Callable[P1, int]):
-    reveal_type(c)  # revealed: (...) -> Unknown
-```
-
-And, using the legacy syntax:
-
-```py
-from typing_extensions import ParamSpec
-
-P2 = ParamSpec("P2")
-
-# TODO: Not an error; remove once `ParamSpec` is supported
-# error: [invalid-type-form]
-def _(c: Callable[P2, int]):
-    reveal_type(c)  # revealed: (...) -> Unknown
-```
-
-## Using `typing.Unpack`
-
-Using the unpack operator (`*`):
-
-```py
-from typing_extensions import Callable, TypeVarTuple
-
-Ts = TypeVarTuple("Ts")
-
-def _(c: Callable[[int, *Ts], int]):
-    reveal_type(c)  # revealed: (*args: @Todo(todo signature *args), **kwargs: @Todo(todo signature **kwargs)) -> int
-```
-
-And, using the legacy syntax using `Unpack`:
-
-```py
-from typing_extensions import Unpack
-
-def _(c: Callable[[int, Unpack[Ts]], int]):
-    reveal_type(c)  # revealed: (*args: @Todo(todo signature *args), **kwargs: @Todo(todo signature **kwargs)) -> int
-```
-
-## Member lookup
-
-```py
-from typing import Callable
-
-def _(c: Callable[[int], int]):
-    reveal_type(c.__init__)  # revealed: Literal[__init__]
-    reveal_type(c.__class__)  # revealed: type
-
-    # TODO: The member lookup for `Callable` uses `object` which does not have a `__call__`
-    # attribute. We could special case `__call__` in this context. Refer to
-    # https://github.com/astral-sh/ruff/pull/16493#discussion_r1985098508 for more details.
-    # error: [unresolved-attribute] "Type `(int, /) -> int` has no attribute `__call__`"
-    reveal_type(c.__call__)  # revealed: Unknown
-```
-
-[gradual form]: https://typing.readthedocs.io/en/latest/spec/glossary.html#term-gradual-form

crates/red_knot_python_semantic/resources/mdtest/annotations/deferred.md

@@ -38,111 +38,9 @@ If `__future__.annotations` is imported, annotations *are* deferred.
 ```py
 from __future__ import annotations
 
-def get_foo() -> Foo:
-    return Foo()
+def get_foo() -> Foo: ...
 
 class Foo: ...
 
 reveal_type(get_foo())  # revealed: Foo
 ```
-
-## Deferred self-reference annotations in a class definition
-
-```py
-from __future__ import annotations
-
-class Foo:
-    this: Foo
-    # error: [unresolved-reference]
-    _ = Foo()
-    # error: [unresolved-reference]
-    [Foo for _ in range(1)]
-    a = int
-
-    def f(self, x: Foo):
-        reveal_type(x)  # revealed: Foo
-
-    def g(self) -> Foo:
-        _: Foo = self
-        return self
-
-    class Bar:
-        foo: Foo
-        b = int
-
-        def f(self, x: Foo):
-            return self
-        # error: [unresolved-reference]
-        def g(self) -> Bar:
-            return self
-        # error: [unresolved-reference]
-        def h[T: Bar](self):
-            pass
-
-        class Baz[T: Foo]:
-            pass
-
-        # error: [unresolved-reference]
-        type S = a
-        type T = b
-
-    def h[T: Bar]():
-        # error: [unresolved-reference]
-        return Bar()
-    type Baz = Foo
-```
-
-## Non-deferred self-reference annotations in a class definition
-
-```py
-class Foo:
-    # error: [unresolved-reference]
-    this: Foo
-    ok: "Foo"
-    # error: [unresolved-reference]
-    _ = Foo()
-    # error: [unresolved-reference]
-    [Foo for _ in range(1)]
-    a = int
-
-    # error: [unresolved-reference]
-    def f(self, x: Foo):
-        reveal_type(x)  # revealed: Unknown
-    # error: [unresolved-reference]
-    def g(self) -> Foo:
-        _: Foo = self
-        return self
-
-    class Bar:
-        # error: [unresolved-reference]
-        foo: Foo
-        b = int
-
-        # error: [unresolved-reference]
-        def f(self, x: Foo):
-            return self
-        # error: [unresolved-reference]
-        def g(self) -> Bar:
-            return self
-        # error: [unresolved-reference]
-        def h[T: Bar](self):
-            pass
-
-        class Baz[T: Foo]:
-            pass
-
-        # error: [unresolved-reference]
-        type S = a
-        type T = b
-
-    def h[T: Bar]():
-        # error: [unresolved-reference]
-        return Bar()
-    type Qux = Foo
-
-def _():
-    class C:
-        # error: [unresolved-reference]
-        def f(self) -> C:
-            return self
-```

crates/red_knot_python_semantic/resources/mdtest/annotations/invalid.md

@@ -1,114 +0,0 @@
-# Tests for invalid types in type expressions
-
-## Invalid types are rejected
-
-Many types are illegal in the context of a type expression:
-
-```py
-import typing
-from knot_extensions import AlwaysTruthy, AlwaysFalsy
-from typing_extensions import Literal, Never
-
-class A: ...
-
-def _(
-    a: type[int],
-    b: AlwaysTruthy,
-    c: AlwaysFalsy,
-    d: Literal[True],
-    e: Literal["bar"],
-    f: Literal[b"foo"],
-    g: tuple[int, str],
-    h: Never,
-    i: int,
-    j: A,
-):
-    def foo(): ...
-    def invalid(
-        a_: a,  # error: [invalid-type-form] "Variable of type `type[int]` is not allowed in a type expression"
-        b_: b,  # error: [invalid-type-form]
-        c_: c,  # error: [invalid-type-form]
-        d_: d,  # error: [invalid-type-form]
-        e_: e,  # error: [invalid-type-form]
-        f_: f,  # error: [invalid-type-form]
-        g_: g,  # error: [invalid-type-form]
-        h_: h,  # error: [invalid-type-form]
-        i_: typing,  # error: [invalid-type-form]
-        j_: foo,  # error: [invalid-type-form]
-        k_: i,  # error: [invalid-type-form] "Variable of type `int` is not allowed in a type expression"
-        l_: j,  # error: [invalid-type-form] "Variable of type `A` is not allowed in a type expression"
-    ):
-        reveal_type(a_)  # revealed: Unknown
-        reveal_type(b_)  # revealed: Unknown
-        reveal_type(c_)  # revealed: Unknown
-        reveal_type(d_)  # revealed: Unknown
-        reveal_type(e_)  # revealed: Unknown
-        reveal_type(f_)  # revealed: Unknown
-        reveal_type(g_)  # revealed: Unknown
-        reveal_type(h_)  # revealed: Unknown
-        reveal_type(i_)  # revealed: Unknown
-        reveal_type(j_)  # revealed: Unknown
-```
-
-## Invalid AST nodes
-
-```py
-def bar() -> None:
-    return None
-
-def _(
-    a: 1,  # error: [invalid-type-form] "Int literals are not allowed in this context in a type expression"
-    b: 2.3,  # error: [invalid-type-form] "Float literals are not allowed in type expressions"
-    c: 4j,  # error: [invalid-type-form] "Complex literals are not allowed in type expressions"
-    d: True,  # error: [invalid-type-form] "Boolean literals are not allowed in this context in a type expression"
-    e: int | b"foo",  # error: [invalid-type-form] "Bytes literals are not allowed in this context in a type expression"
-    f: 1 and 2,  # error: [invalid-type-form] "Boolean operations are not allowed in type expressions"
-    g: 1 or 2,  # error: [invalid-type-form] "Boolean operations are not allowed in type expressions"
-    h: (foo := 1),  # error: [invalid-type-form] "Named expressions are not allowed in type expressions"
-    i: not 1,  # error: [invalid-type-form] "Unary operations are not allowed in type expressions"
-    j: lambda: 1,  # error: [invalid-type-form] "`lambda` expressions are not allowed in type expressions"
-    k: 1 if True else 2,  # error: [invalid-type-form] "`if` expressions are not allowed in type expressions"
-    l: await 1,  # error: [invalid-type-form] "`await` expressions are not allowed in type expressions"
-    m: (yield 1),  # error: [invalid-type-form] "`yield` expressions are not allowed in type expressions"
-    n: (yield from [1]),  # error: [invalid-type-form] "`yield from` expressions are not allowed in type expressions"
-    o: 1 < 2,  # error: [invalid-type-form] "Comparison expressions are not allowed in type expressions"
-    p: bar(),  # error: [invalid-type-form] "Function calls are not allowed in type expressions"
-    q: int | f"foo",  # error: [invalid-type-form] "F-strings are not allowed in type expressions"
-    r: [1, 2, 3][1:2],  # error: [invalid-type-form] "Slices are not allowed in type expressions"
-):
-    reveal_type(a)  # revealed: Unknown
-    reveal_type(b)  # revealed: Unknown
-    reveal_type(c)  # revealed: Unknown
-    reveal_type(d)  # revealed: Unknown
-    reveal_type(e)  # revealed: int | Unknown
-    reveal_type(f)  # revealed: Unknown
-    reveal_type(g)  # revealed: Unknown
-    reveal_type(h)  # revealed: Unknown
-    reveal_type(i)  # revealed: Unknown
-    reveal_type(j)  # revealed: Unknown
-    reveal_type(k)  # revealed: Unknown
-    reveal_type(p)  # revealed: Unknown
-    reveal_type(q)  # revealed: int | Unknown
-    reveal_type(r)  # revealed: @Todo(generics)
-```
-
-## Invalid Collection based AST nodes
-
-```py
-def _(
-    a: {1: 2},  # error: [invalid-type-form] "Dict literals are not allowed in type expressions"
-    b: {1, 2},  # error: [invalid-type-form] "Set literals are not allowed in type expressions"
-    c: {k: v for k, v in [(1, 2)]},  # error: [invalid-type-form] "Dict comprehensions are not allowed in type expressions"
-    d: [k for k in [1, 2]],  # error: [invalid-type-form] "List comprehensions are not allowed in type expressions"
-    e: {k for k in [1, 2]},  # error: [invalid-type-form] "Set comprehensions are not allowed in type expressions"
-    f: (k for k in [1, 2]),  # error: [invalid-type-form] "Generator expressions are not allowed in type expressions"
-    g: [int, str],  # error: [invalid-type-form] "List literals are not allowed in this context in a type expression"
-):
-    reveal_type(a)  # revealed: Unknown
-    reveal_type(b)  # revealed: Unknown
-    reveal_type(c)  # revealed: Unknown
-    reveal_type(d)  # revealed: Unknown
-    reveal_type(e)  # revealed: Unknown
-    reveal_type(f)  # revealed: Unknown
-    reveal_type(g)  # revealed: Unknown
-```

crates/red_knot_python_semantic/resources/mdtest/annotations/literal.md

@@ -36,7 +36,7 @@ def f():
     reveal_type(a7)  # revealed: None
     reveal_type(a8)  # revealed: Literal[1]
     # TODO: This should be Color.RED
-    reveal_type(b1)  # revealed: @Todo(Attribute access on enum classes)
+    reveal_type(b1)  # revealed: Unknown | Literal[0]
 
 # error: [invalid-type-form]
 invalid1: Literal[3 + 4]
@@ -127,13 +127,6 @@ Literal: _SpecialForm
 ```py
 from other import Literal
 
-# TODO: can we add a subdiagnostic here saying something like:
-#
-#     `other.Literal` and `typing.Literal` have similar names, but are different symbols and don't have the same semantics
-#
-# ?
-#
-# error: [invalid-type-form] "Int literals are not allowed in this context in a type expression"
 a1: Literal[26]
 
 def f():
@@ -156,7 +149,7 @@ def f():
 ```py
 from typing import Literal
 
-# error: [invalid-type-form] "`typing.Literal` requires at least one argument when used in a type expression"
+# error: [invalid-type-form] "`Literal` requires at least one argument when used in a type expression"
 def _(x: Literal):
     reveal_type(x)  # revealed: Unknown
 ```

crates/red_knot_python_semantic/resources/mdtest/annotations/literal_string.md

@@ -73,12 +73,12 @@ qux = (foo, bar)
 reveal_type(qux)  # revealed: tuple[Literal["foo"], Literal["bar"]]
 
 # TODO: Infer "LiteralString"
-reveal_type(foo.join(qux))  # revealed: @Todo(return type of overloaded function)
+reveal_type(foo.join(qux))  # revealed: @Todo(decorated method)
 
 template: LiteralString = "{}, {}"
 reveal_type(template)  # revealed: Literal["{}, {}"]
 # TODO: Infer `LiteralString`
-reveal_type(template.format(foo, bar))  # revealed: @Todo(return type of overloaded function)
+reveal_type(template.format(foo, bar))  # revealed: @Todo(decorated method)
 ```
 
 ### Assignability

crates/red_knot_python_semantic/resources/mdtest/annotations/new_types.md

@@ -1,20 +0,0 @@
-# NewType
-
-Currently, red-knot doesn't support `typing.NewType` in type annotations.
-
-## Valid forms
-
-```py
-from typing_extensions import NewType
-from types import GenericAlias
-
-A = NewType("A", int)
-B = GenericAlias(A, ())
-
-def _(
-    a: A,
-    b: B,
-):
-    reveal_type(a)  # revealed: @Todo(Support for `typing.NewType` instances in type expressions)
-    reveal_type(b)  # revealed: @Todo(Support for `typing.GenericAlias` instances in type expressions)
-```

crates/red_knot_python_semantic/resources/mdtest/annotations/optional.md

@@ -45,13 +45,3 @@ def f():
     # revealed: int | None
     reveal_type(a)
 ```
-
-## Invalid
-
-```py
-from typing import Optional
-
-# error: [invalid-type-form] "`typing.Optional` requires exactly one argument when used in a type expression"
-def f(x: Optional) -> None:
-    reveal_type(x)  # revealed: Unknown
-```

crates/red_knot_python_semantic/resources/mdtest/annotations/stdlib_typing_aliases.md

@@ -70,7 +70,8 @@ import typing
 
 class ListSubclass(typing.List): ...
 
-# revealed: tuple[Literal[ListSubclass], Literal[list], Literal[MutableSequence], Literal[Sequence], Literal[Reversible], Literal[Collection], Literal[Iterable], Literal[Container], @Todo(protocol), Literal[object]]
+# TODO: should have `Generic`, should not have `Unknown`
+# revealed: tuple[Literal[ListSubclass], Literal[list], Unknown, Literal[object]]
 reveal_type(ListSubclass.__mro__)
 
 class DictSubclass(typing.Dict): ...
@@ -81,7 +82,8 @@ reveal_type(DictSubclass.__mro__)
 
 class SetSubclass(typing.Set): ...
 
-# revealed: tuple[Literal[SetSubclass], Literal[set], Literal[MutableSet], Literal[AbstractSet], Literal[Collection], Literal[Iterable], Literal[Container], @Todo(protocol), Literal[object]]
+# TODO: should have `Generic`, should not have `Unknown`
+# revealed: tuple[Literal[SetSubclass], Literal[set], Unknown, Literal[object]]
 reveal_type(SetSubclass.__mro__)
 
 class FrozenSetSubclass(typing.FrozenSet): ...
@@ -113,7 +115,8 @@ reveal_type(DefaultDictSubclass.__mro__)
 
 class DequeSubclass(typing.Deque): ...
 
-# revealed: tuple[Literal[DequeSubclass], Literal[deque], Literal[MutableSequence], Literal[Sequence], Literal[Reversible], Literal[Collection], Literal[Iterable], Literal[Container], @Todo(protocol), Literal[object]]
+# TODO: Should be (DequeSubclass, deque, MutableSequence, Sequence, Reversible, Collection, Sized, Iterable, Container, Generic, object)
+# revealed: tuple[Literal[DequeSubclass], Literal[deque], Unknown, Literal[object]]
 reveal_type(DequeSubclass.__mro__)
 
 class OrderedDictSubclass(typing.OrderedDict): ...

crates/red_knot_python_semantic/resources/mdtest/annotations/string.md

@@ -116,8 +116,8 @@ MyType = int
 class Aliases:
     MyType = str
 
-    forward: "MyType" = "value"
-    not_forward: MyType = "value"
+    forward: "MyType"
+    not_forward: MyType
 
 reveal_type(Aliases.forward)  # revealed: str
 reveal_type(Aliases.not_forward)  # revealed: str

crates/red_knot_python_semantic/resources/mdtest/annotations/union.md

@@ -59,13 +59,3 @@ def f():
     # revealed: int | str
     reveal_type(a)
 ```
-
-## Invalid
-
-```py
-from typing import Union
-
-# error: [invalid-type-form] "`typing.Union` requires at least one argument when used in a type expression"
-def f(x: Union) -> None:
-    reveal_type(x)  # revealed: Unknown
-```

crates/red_knot_python_semantic/resources/mdtest/annotations/unsupported_special_forms.md

@@ -18,7 +18,7 @@ def f(*args: Unpack[Ts]) -> tuple[Unpack[Ts]]:
     # TODO: should understand the annotation
     reveal_type(args)  # revealed: tuple
 
-    reveal_type(Alias)  # revealed: @Todo(Support for `typing.TypeAlias`)
+    reveal_type(Alias)  # revealed: @Todo(Unsupported or invalid type in a type expression)
 
 def g() -> TypeGuard[int]: ...
 def h() -> TypeIs[int]: ...
@@ -33,30 +33,7 @@ def i(callback: Callable[Concatenate[int, P], R_co], *args: P.args, **kwargs: P.
 
 class Foo:
     def method(self, x: Self):
-        reveal_type(x)  # revealed: @Todo(Support for `typing.Self`)
-```
-
-## Type expressions
-
-One thing that is supported is error messages for using special forms in type expressions.
-
-```py
-from typing_extensions import Unpack, TypeGuard, TypeIs, Concatenate, ParamSpec
-
-def _(
-    a: Unpack,  # error: [invalid-type-form] "`typing.Unpack` requires exactly one argument when used in a type expression"
-    b: TypeGuard,  # error: [invalid-type-form] "`typing.TypeGuard` requires exactly one argument when used in a type expression"
-    c: TypeIs,  # error: [invalid-type-form] "`typing.TypeIs` requires exactly one argument when used in a type expression"
-    d: Concatenate,  # error: [invalid-type-form] "`typing.Concatenate` requires at least two arguments when used in a type expression"
-    e: ParamSpec,
-) -> None:
-    reveal_type(a)  # revealed: Unknown
-    reveal_type(b)  # revealed: Unknown
-    reveal_type(c)  # revealed: Unknown
-    reveal_type(d)  # revealed: Unknown
-
-    def foo(a_: e) -> None:
-        reveal_type(a_)  # revealed: @Todo(Support for `typing.ParamSpec`)
+        reveal_type(x)  # revealed: @Todo(Unsupported or invalid type in a type expression)
 ```
 
 ## Inheritance

crates/red_knot_python_semantic/resources/mdtest/annotations/unsupported_type_qualifiers.md

@@ -1,6 +1,6 @@
 # Unsupported type qualifiers
 
-## Not yet fully supported
+## Not yet supported
 
 Several type qualifiers are unsupported by red-knot currently. However, we also don't emit
 false-positive errors if you use one in an annotation:
@@ -19,33 +19,6 @@ class Bar(TypedDict):
     z: ReadOnly[bytes]
 ```
 
-## Type expressions
-
-One thing that is supported is error messages for using type qualifiers in type expressions.
-
-```py
-from typing_extensions import Final, ClassVar, Required, NotRequired, ReadOnly
-
-def _(
-    a: (
-        Final  # error: [invalid-type-form] "Type qualifier `typing.Final` is not allowed in type expressions (only in annotation expressions)"
-        | int
-    ),
-    b: (
-        ClassVar  # error: [invalid-type-form] "Type qualifier `typing.ClassVar` is not allowed in type expressions (only in annotation expressions)"
-        | int
-    ),
-    c: Required,  # error: [invalid-type-form] "Type qualifier `typing.Required` is not allowed in type expressions (only in annotation expressions, and only with exactly one argument)"
-    d: NotRequired,  # error: [invalid-type-form] "Type qualifier `typing.NotRequired` is not allowed in type expressions (only in annotation expressions, and only with exactly one argument)"
-    e: ReadOnly,  # error: [invalid-type-form] "Type qualifier `typing.ReadOnly` is not allowed in type expressions (only in annotation expressions, and only with exactly one argument)"
-) -> None:
-    reveal_type(a)  # revealed: Unknown | int
-    reveal_type(b)  # revealed: Unknown | int
-    reveal_type(c)  # revealed: Unknown
-    reveal_type(d)  # revealed: Unknown
-    reveal_type(e)  # revealed: Unknown
-```
-
 ## Inheritance
 
 You can't inherit from a type qualifier.

crates/red_knot_python_semantic/resources/mdtest/assignment/annotations.md

@@ -52,11 +52,13 @@ reveal_type(b)  # revealed: tuple[int]
 reveal_type(c)  # revealed: tuple[str, int]
 reveal_type(d)  # revealed: tuple[tuple[str, str], tuple[int, int]]
 
-# TODO: homogeneous tuples, PEP-646 tuples, generics
+# TODO: homogeneous tuples, PEP-646 tuples
 reveal_type(e)  # revealed: @Todo(full tuple[...] support)
 reveal_type(f)  # revealed: @Todo(full tuple[...] support)
 reveal_type(g)  # revealed: @Todo(full tuple[...] support)
-reveal_type(h)  # revealed: tuple[@Todo(generics), @Todo(generics)]
+
+# TODO: support more kinds of type expressions in annotations
+reveal_type(h)  # revealed: @Todo(full tuple[...] support)
 
 reveal_type(i)  # revealed: tuple[str | int, str | int]
 reveal_type(j)  # revealed: tuple[str | int]

crates/red_knot_python_semantic/resources/mdtest/assignment/augmented.md

@@ -10,10 +10,6 @@ reveal_type(x)  # revealed: Literal[2]
 x = 1.0
 x /= 2
 reveal_type(x)  # revealed: int | float
-
-x = (1, 2)
-x += (3, 4)
-reveal_type(x)  # revealed: tuple[Literal[1], Literal[2], Literal[3], Literal[4]]
 ```
 
 ## Dunder methods
@@ -79,7 +75,8 @@ def _(flag: bool):
 
     f = Foo()
 
-    # error: [unsupported-operator] "Operator `+=` is unsupported between objects of type `Foo` and `Literal["Hello, world!"]`"
+    # TODO: We should emit an `unsupported-operator` error here, possibly with the information
+    # that `Foo.__iadd__` may be unbound as additional context.
     f += "Hello, world!"
 
     reveal_type(f)  # revealed: int | Unknown
@@ -165,18 +162,3 @@ def f(flag: bool, flag2: bool):
 
     reveal_type(f)  # revealed: int | str | float
 ```
-
-## Implicit dunder calls on class objects
-
-```py
-class Meta(type):
-    def __iadd__(cls, other: int) -> str:
-        return ""
-
-class C(metaclass=Meta): ...
-
-cls = C
-cls += 1
-
-reveal_type(cls)  # revealed: str
-```

crates/red_knot_python_semantic/resources/mdtest/attributes.md

@@ -54,12 +54,13 @@ c_instance.declared_and_bound = False
 # error: [invalid-assignment] "Object of type `Literal["incompatible"]` is not assignable to attribute `declared_and_bound` of type `bool`"
 c_instance.declared_and_bound = "incompatible"
 
+# TODO: we already show an error here but the message might be improved?
 # mypy shows no error here, but pyright raises "reportAttributeAccessIssue"
-# error: [unresolved-attribute] "Attribute `inferred_from_value` can only be accessed on instances, not on the class object `Literal[C]` itself."
+# error: [unresolved-attribute] "Type `Literal[C]` has no attribute `inferred_from_value`"
 reveal_type(C.inferred_from_value)  # revealed: Unknown
 
+# TODO: this should be an error (pure instance variables cannot be accessed on the class)
 # mypy shows no error here, but pyright raises "reportAttributeAccessIssue"
-# error: [invalid-attribute-access] "Cannot assign to instance attribute `inferred_from_value` from the class object `Literal[C]`"
 C.inferred_from_value = "overwritten on class"
 
 # This assignment is fine:
@@ -89,13 +90,13 @@ c_instance = C()
 
 reveal_type(c_instance.declared_and_bound)  # revealed: str | None
 
-# Note that both mypy and pyright show no error in this case! So we may reconsider this in
-# the future, if it turns out to produce too many false positives. We currently emit:
-# error: [unresolved-attribute] "Attribute `declared_and_bound` can only be accessed on instances, not on the class object `Literal[C]` itself."
-reveal_type(C.declared_and_bound)  # revealed: Unknown
+# TODO: we currently plan to emit a diagnostic here. Note that both mypy
+# and pyright show no error in this case! So we may reconsider this in
+# the future, if it turns out to produce too many false positives.
+reveal_type(C.declared_and_bound)  # revealed: str | None
 
-# Same as above. Mypy and pyright do not show an error here.
-# error: [invalid-attribute-access] "Cannot assign to instance attribute `declared_and_bound` from the class object `Literal[C]`"
+# TODO: same as above. We plan to emit a diagnostic here, even if both mypy
+# and pyright allow this.
 C.declared_and_bound = "overwritten on class"
 
 # error: [invalid-assignment] "Object of type `Literal[1]` is not assignable to attribute `declared_and_bound` of type `str | None`"
@@ -115,11 +116,11 @@ c_instance = C()
 
 reveal_type(c_instance.only_declared)  # revealed: str
 
-# Mypy and pyright do not show an error here. We treat this as a pure instance variable.
-# error: [unresolved-attribute] "Attribute `only_declared` can only be accessed on instances, not on the class object `Literal[C]` itself."
-reveal_type(C.only_declared)  # revealed: Unknown
+# TODO: mypy and pyright do not show an error here, but we plan to emit a diagnostic.
+# The type could be changed to 'Unknown' if we decide to emit an error?
+reveal_type(C.only_declared)  # revealed: str
 
-# error: [invalid-attribute-access] "Cannot assign to instance attribute `only_declared` from the class object `Literal[C]`"
+# TODO: mypy and pyright do not show an error here, but we plan to emit one.
 C.only_declared = "overwritten on class"
 ```
 
@@ -155,9 +156,7 @@ reveal_type(c_instance.declared_in_body_and_init)  # revealed: str | None
 
 reveal_type(c_instance.declared_in_body_defined_in_init)  # revealed: str | None
 
-# TODO: This should be `str | None`. Fixing this requires an overhaul of the `Symbol` API,
-# which is planned in https://github.com/astral-sh/ruff/issues/14297
-reveal_type(c_instance.bound_in_body_declared_in_init)  # revealed: Unknown | str | None
+reveal_type(c_instance.bound_in_body_declared_in_init)  # revealed: str | None
 
 reveal_type(c_instance.bound_in_body_and_init)  # revealed: Unknown | None | Literal["a"]
 ```
@@ -192,10 +191,11 @@ reveal_type(c_instance.declared_only)  # revealed: bytes
 
 reveal_type(c_instance.declared_and_bound)  # revealed: bool
 
-# error: [unresolved-attribute] "Attribute `inferred_from_value` can only be accessed on instances, not on the class object `Literal[C]` itself."
+# TODO: We already show an error here, but the message might be improved?
+# error: [unresolved-attribute]
 reveal_type(C.inferred_from_value)  # revealed: Unknown
 
-# error: [invalid-attribute-access] "Cannot assign to instance attribute `inferred_from_value` from the class object `Literal[C]`"
+# TODO: this should be an error
 C.inferred_from_value = "overwritten on class"
 ```
 
@@ -348,11 +348,8 @@ reveal_type(C().y)  # revealed: Unknown | str
 
 ```py
 class ContextManager:
-    def __enter__(self) -> int | None:
-        return 1
-
-    def __exit__(self, exc_type, exc_value, traceback) -> None:
-        pass
+    def __enter__(self) -> int | None: ...
+    def __exit__(self, exc_type, exc_value, traceback) -> None: ...
 
 class C:
     def __init__(self) -> None:
@@ -361,28 +358,9 @@ class C:
 
 c_instance = C()
 
-reveal_type(c_instance.x)  # revealed: Unknown | int | None
-```
-
-#### Attributes defined in `with` statements, but with unpacking
-
-```py
-class ContextManager:
-    def __enter__(self) -> tuple[int | None, int]:
-        return 1, 2
-
-    def __exit__(self, exc_type, exc_value, traceback) -> None:
-        pass
-
-class C:
-    def __init__(self) -> None:
-        with ContextManager() as (self.x, self.y):
-            pass
-
-c_instance = C()
-
-reveal_type(c_instance.x)  # revealed: Unknown | int | None
-reveal_type(c_instance.y)  # revealed: Unknown | int
+# TODO: Should be `Unknown | int | None`
+# error: [unresolved-attribute]
+reveal_type(c_instance.x)  # revealed: Unknown
 ```
 
 #### Attributes defined in comprehensions
@@ -551,7 +529,6 @@ reveal_type(C().x)  # revealed: str
 class C:
     def __init__(self) -> None:
         # error: [too-many-positional-arguments]
-        # error: [invalid-argument-type]
         self.x: int = len(1, 2, 3)
 ```
 
@@ -621,9 +598,6 @@ C.class_method()
 # error: [unresolved-attribute]
 reveal_type(C.pure_class_variable)  # revealed: Unknown
 
-# TODO: should be no error when descriptor protocol is supported
-# and the assignment is properly attributed to the class method.
-# error: [invalid-attribute-access] "Cannot assign to instance attribute `pure_class_variable` from the class object `Literal[C]`"
 C.pure_class_variable = "overwritten on class"
 
 # TODO: should be  `Unknown | Literal["value set in class method"]` or
@@ -698,10 +672,10 @@ class Base:
         self.defined_in_init: str | None = "value in base"
 
 class Intermediate(Base):
-    # Redeclaring base class attributes with the *same *type is fine:
+    # Re-declaring base class attributes with the *same *type is fine:
     base_class_attribute_1: str | None = None
 
-    # Redeclaring them with a *narrower type* is unsound, because modifications
+    # Re-declaring them with a *narrower type* is unsound, because modifications
     # through a `Base` reference could violate that constraint.
     #
     # Mypy does not report an error here, but pyright does: "… overrides symbol
@@ -713,7 +687,7 @@ class Intermediate(Base):
     # TODO: This should be an error
     base_class_attribute_2: str
 
-    # Redeclaring attributes with a *wider type* directly violates LSP.
+    # Re-declaring attributes with a *wider type* directly violates LSP.
     #
     # In this case, both mypy and pyright report an error.
     #
@@ -729,349 +703,26 @@ reveal_type(Derived().declared_in_body)  # revealed: int | None
 reveal_type(Derived().defined_in_init)  # revealed: str | None
 ```
 
-## Accessing attributes on class objects
-
-When accessing attributes on class objects, they are always looked up on the type of the class
-object first, i.e. on the metaclass:
-
-```py
-from typing import Literal
-
-class Meta1:
-    attr: Literal["metaclass value"] = "metaclass value"
-
-class C1(metaclass=Meta1): ...
-
-reveal_type(C1.attr)  # revealed: Literal["metaclass value"]
-```
-
-However, the metaclass attribute only takes precedence over a class-level attribute if it is a data
-descriptor. If it is a non-data descriptor or a normal attribute, the class-level attribute is used
-instead (see the [descriptor protocol tests] for data/non-data descriptor attributes):
-
-```py
-class Meta2:
-    attr: str = "metaclass value"
-
-class C2(metaclass=Meta2):
-    attr: Literal["class value"] = "class value"
-
-reveal_type(C2.attr)  # revealed: Literal["class value"]
-```
-
-If the class-level attribute is only partially defined, we union the metaclass attribute with the
-class-level attribute:
-
-```py
-def _(flag: bool):
-    class Meta3:
-        attr1 = "metaclass value"
-        attr2: Literal["metaclass value"] = "metaclass value"
-
-    class C3(metaclass=Meta3):
-        if flag:
-            attr1 = "class value"
-            # TODO: Neither mypy nor pyright show an error here, but we could consider emitting a conflicting-declaration diagnostic here.
-            attr2: Literal["class value"] = "class value"
-
-    reveal_type(C3.attr1)  # revealed: Unknown | Literal["metaclass value", "class value"]
-    reveal_type(C3.attr2)  # revealed: Literal["metaclass value", "class value"]
-```
-
-If the *metaclass* attribute is only partially defined, we emit a `possibly-unbound-attribute`
-diagnostic:
-
-```py
-def _(flag: bool):
-    class Meta4:
-        if flag:
-            attr1: str = "metaclass value"
-
-    class C4(metaclass=Meta4): ...
-    # error: [possibly-unbound-attribute]
-    reveal_type(C4.attr1)  # revealed: str
-```
-
-Finally, if both the metaclass attribute and the class-level attribute are only partially defined,
-we union them and emit a `possibly-unbound-attribute` diagnostic:
-
-```py
-def _(flag1: bool, flag2: bool):
-    class Meta5:
-        if flag1:
-            attr1 = "metaclass value"
-
-    class C5(metaclass=Meta5):
-        if flag2:
-            attr1 = "class value"
-
-    # error: [possibly-unbound-attribute]
-    reveal_type(C5.attr1)  # revealed: Unknown | Literal["metaclass value", "class value"]
-```
-
-## Unions of attributes
-
-If the (meta)class is a union type or if the attribute on the (meta) class has a union type, we
-infer those union types accordingly:
+## Union of attributes
 
 ```py
 def _(flag: bool):
     if flag:
         class C1:
             x = 1
-            y: int = 1
 
     else:
         class C1:
             x = 2
-            y: int | str = "b"
-
-    reveal_type(C1.x)  # revealed: Unknown | Literal[1, 2]
-    reveal_type(C1.y)  # revealed: int | str
-
-    C1.y = 100
-    # error: [invalid-assignment] "Object of type `Literal["problematic"]` is not assignable to attribute `y` on type `Literal[C1, C1]`"
-    C1.y = "problematic"
 
     class C2:
         if flag:
             x = 3
-            y: int = 3
         else:
             x = 4
-            y: int | str = "d"
 
+    reveal_type(C1.x)  # revealed: Unknown | Literal[1, 2]
     reveal_type(C2.x)  # revealed: Unknown | Literal[3, 4]
-    reveal_type(C2.y)  # revealed: int | str
-
-    C2.y = 100
-    # error: [invalid-assignment] "Object of type `None` is not assignable to attribute `y` of type `int | str`"
-    C2.y = None
-    # TODO: should be an error, needs more sophisticated union handling in `validate_attribute_assignment`
-    C2.y = "problematic"
-
-    if flag:
-        class Meta3(type):
-            x = 5
-            y: int = 5
-
-    else:
-        class Meta3(type):
-            x = 6
-            y: int | str = "f"
-
-    class C3(metaclass=Meta3): ...
-    reveal_type(C3.x)  # revealed: Unknown | Literal[5, 6]
-    reveal_type(C3.y)  # revealed: int | str
-
-    C3.y = 100
-    # error: [invalid-assignment] "Object of type `None` is not assignable to attribute `y` of type `int | str`"
-    C3.y = None
-    # TODO: should be an error, needs more sophisticated union handling in `validate_attribute_assignment`
-    C3.y = "problematic"
-
-    class Meta4(type):
-        if flag:
-            x = 7
-            y: int = 7
-        else:
-            x = 8
-            y: int | str = "h"
-
-    class C4(metaclass=Meta4): ...
-    reveal_type(C4.x)  # revealed: Unknown | Literal[7, 8]
-    reveal_type(C4.y)  # revealed: int | str
-
-    C4.y = 100
-    # error: [invalid-assignment] "Object of type `None` is not assignable to attribute `y` of type `int | str`"
-    C4.y = None
-    # TODO: should be an error, needs more sophisticated union handling in `validate_attribute_assignment`
-    C4.y = "problematic"
-```
-
-## Unions with possibly unbound paths
-
-### Definite boundness within a class
-
-In this example, the `x` attribute is not defined in the `C2` element of the union:
-
-```py
-def _(flag1: bool, flag2: bool):
-    class C1:
-        x = 1
-
-    class C2: ...
-
-    class C3:
-        x = 3
-
-    C = C1 if flag1 else C2 if flag2 else C3
-
-    # error: [possibly-unbound-attribute] "Attribute `x` on type `Literal[C1, C2, C3]` is possibly unbound"
-    reveal_type(C.x)  # revealed: Unknown | Literal[1, 3]
-
-    # error: [invalid-assignment] "Object of type `Literal[100]` is not assignable to attribute `x` on type `Literal[C1, C2, C3]`"
-    C.x = 100
-
-    # error: [possibly-unbound-attribute] "Attribute `x` on type `C1 | C2 | C3` is possibly unbound"
-    reveal_type(C().x)  # revealed: Unknown | Literal[1, 3]
-
-    # error: [invalid-assignment] "Object of type `Literal[100]` is not assignable to attribute `x` on type `C1 | C2 | C3`"
-    C().x = 100
-```
-
-### Possibly-unbound within a class
-
-We raise the same diagnostic if the attribute is possibly-unbound in at least one element of the
-union:
-
-```py
-def _(flag: bool, flag1: bool, flag2: bool):
-    class C1:
-        x = 1
-
-    class C2:
-        if flag:
-            x = 2
-
-    class C3:
-        x = 3
-
-    C = C1 if flag1 else C2 if flag2 else C3
-
-    # error: [possibly-unbound-attribute] "Attribute `x` on type `Literal[C1, C2, C3]` is possibly unbound"
-    reveal_type(C.x)  # revealed: Unknown | Literal[1, 2, 3]
-
-    # error: [possibly-unbound-attribute]
-    C.x = 100
-
-    # Note: we might want to consider ignoring possibly-unbound diagnostics for instance attributes eventually,
-    # see the "Possibly unbound/undeclared instance attribute" section below.
-    # error: [possibly-unbound-attribute] "Attribute `x` on type `C1 | C2 | C3` is possibly unbound"
-    reveal_type(C().x)  # revealed: Unknown | Literal[1, 2, 3]
-
-    # error: [possibly-unbound-attribute]
-    C().x = 100
-```
-
-### Possibly-unbound within gradual types
-
-```py
-from typing import Any
-
-def _(flag: bool):
-    class Base:
-        x: Any
-
-    class Derived(Base):
-        if flag:
-            # Redeclaring `x` with a more static type is okay in terms of LSP.
-            x: int
-
-    reveal_type(Derived().x)  # revealed: int | Any
-
-    Derived().x = 1
-    Derived().x = "a"
-```
-
-### Attribute possibly unbound on a subclass but not on a superclass
-
-```py
-def _(flag: bool):
-    class Foo:
-        x = 1
-
-    class Bar(Foo):
-        if flag:
-            x = 2
-
-    reveal_type(Bar.x)  # revealed: Unknown | Literal[2, 1]
-    Bar.x = 3
-
-    reveal_type(Bar().x)  # revealed: Unknown | Literal[2, 1]
-    Bar().x = 3
-```
-
-### Attribute possibly unbound on a subclass and on a superclass
-
-```py
-def _(flag: bool):
-    class Foo:
-        if flag:
-            x = 1
-
-    class Bar(Foo):
-        if flag:
-            x = 2
-
-    # error: [possibly-unbound-attribute]
-    reveal_type(Bar.x)  # revealed: Unknown | Literal[2, 1]
-
-    # error: [possibly-unbound-attribute]
-    Bar.x = 3
-
-    # error: [possibly-unbound-attribute]
-    reveal_type(Bar().x)  # revealed: Unknown | Literal[2, 1]
-
-    # error: [possibly-unbound-attribute]
-    Bar().x = 3
-```
-
-### Possibly unbound/undeclared instance attribute
-
-#### Possibly unbound and undeclared
-
-```py
-def _(flag: bool):
-    class Foo:
-        if flag:
-            x: int
-
-        def __init(self):
-            if flag:
-                self.x = 1
-
-    # error: [possibly-unbound-attribute]
-    reveal_type(Foo().x)  # revealed: int | Unknown
-
-    # error: [possibly-unbound-attribute]
-    Foo().x = 1
-```
-
-#### Possibly unbound
-
-```py
-def _(flag: bool):
-    class Foo:
-        def __init(self):
-            if flag:
-                self.x = 1
-
-    # Emitting a diagnostic in a case like this is not something we support, and it's unclear
-    # if we ever will (or want to)
-    reveal_type(Foo().x)  # revealed: Unknown | Literal[1]
-
-    # Same here
-    Foo().x = 2
-```
-
-### Unions with all paths unbound
-
-If the symbol is unbound in all elements of the union, we detect that:
-
-```py
-def _(flag: bool):
-    class C1: ...
-    class C2: ...
-    C = C1 if flag else C2
-
-    # error: [unresolved-attribute] "Type `Literal[C1, C2]` has no attribute `x`"
-    reveal_type(C.x)  # revealed: Unknown
-
-    # TODO: This should ideally be a `unresolved-attribute` error. We need better union
-    # handling in `validate_attribute_assignment` for this.
-    # error: [invalid-assignment] "Object of type `Literal[1]` is not assignable to attribute `x` on type `Literal[C1, C2]`"
-    C.x = 1
 ```
 
 ## Inherited class attributes
@@ -1086,8 +737,6 @@ class B(A): ...
 class C(B): ...
 
 reveal_type(C.X)  # revealed: Unknown | Literal["foo"]
-
-C.X = "bar"
 ```
 
 ### Multiple inheritance
@@ -1111,168 +760,84 @@ reveal_type(A.__mro__)
 
 # `E` is earlier in the MRO than `F`, so we should use the type of `E.X`
 reveal_type(A.X)  # revealed: Unknown | Literal[42]
-
-A.X = 100
 ```
 
-## Intersections of attributes
+## Unions with possibly unbound paths
 
-### Attribute only available on one element
+### Definite boundness within a class
+
+In this example, the `x` attribute is not defined in the `C2` element of the union:
 
 ```py
-from knot_extensions import Intersection
+def _(flag1: bool, flag2: bool):
+    class C1:
+        x = 1
 
-class A:
-    x: int = 1
+    class C2: ...
 
-class B: ...
+    class C3:
+        x = 3
 
-def _(a_and_b: Intersection[A, B]):
-    reveal_type(a_and_b.x)  # revealed: int
+    C = C1 if flag1 else C2 if flag2 else C3
 
-    a_and_b.x = 2
-
-# Same for class objects
-def _(a_and_b: Intersection[type[A], type[B]]):
-    reveal_type(a_and_b.x)  # revealed: int
-
-    a_and_b.x = 2
+    # error: [possibly-unbound-attribute] "Attribute `x` on type `Literal[C1, C2, C3]` is possibly unbound"
+    reveal_type(C.x)  # revealed: Unknown | Literal[1, 3]
 ```
 
-### Attribute available on both elements
+### Possibly-unbound within a class
+
+We raise the same diagnostic if the attribute is possibly-unbound in at least one element of the
+union:
 
 ```py
-from knot_extensions import Intersection
+def _(flag: bool, flag1: bool, flag2: bool):
+    class C1:
+        x = 1
 
-class P: ...
-class Q: ...
-class R(P, Q): ...
+    class C2:
+        if flag:
+            x = 2
 
-class A:
-    x: P = P()
+    class C3:
+        x = 3
 
-class B:
-    x: Q = Q()
+    C = C1 if flag1 else C2 if flag2 else C3
 
-def _(a_and_b: Intersection[A, B]):
-    reveal_type(a_and_b.x)  # revealed: P & Q
-    a_and_b.x = R()
-
-# Same for class objects
-def _(a_and_b: Intersection[type[A], type[B]]):
-    reveal_type(a_and_b.x)  # revealed: P & Q
-    a_and_b.x = R()
+    # error: [possibly-unbound-attribute] "Attribute `x` on type `Literal[C1, C2, C3]` is possibly unbound"
+    reveal_type(C.x)  # revealed: Unknown | Literal[1, 2, 3]
 ```
 
-### Possible unboundness
+### Attribute possibly unbound on a subclass but not on a superclass
 
 ```py
-from knot_extensions import Intersection
-
-class P: ...
-class Q: ...
-class R(P, Q): ...
-
 def _(flag: bool):
-    class A1:
+    class Foo:
+        x = 1
+
+    class Bar(Foo):
         if flag:
-            x: P = P()
+            x = 2
 
-    class B1: ...
-
-    def inner1(a_and_b: Intersection[A1, B1]):
-        # error: [possibly-unbound-attribute]
-        reveal_type(a_and_b.x)  # revealed: P
-
-        # error: [possibly-unbound-attribute]
-        a_and_b.x = R()
-    # Same for class objects
-    def inner1_class(a_and_b: Intersection[type[A1], type[B1]]):
-        # error: [possibly-unbound-attribute]
-        reveal_type(a_and_b.x)  # revealed: P
-
-        # error: [possibly-unbound-attribute]
-        a_and_b.x = R()
-
-    class A2:
-        if flag:
-            x: P = P()
-
-    class B1:
-        x: Q = Q()
-
-    def inner2(a_and_b: Intersection[A2, B1]):
-        reveal_type(a_and_b.x)  # revealed: P & Q
-
-        # TODO: this should not be an error, we need better intersection
-        # handling in `validate_attribute_assignment` for this
-        # error: [possibly-unbound-attribute]
-        a_and_b.x = R()
-    # Same for class objects
-    def inner2_class(a_and_b: Intersection[type[A2], type[B1]]):
-        reveal_type(a_and_b.x)  # revealed: P & Q
-
-    class A3:
-        if flag:
-            x: P = P()
-
-    class B3:
-        if flag:
-            x: Q = Q()
-
-    def inner3(a_and_b: Intersection[A3, B3]):
-        # error: [possibly-unbound-attribute]
-        reveal_type(a_and_b.x)  # revealed: P & Q
-
-        # error: [possibly-unbound-attribute]
-        a_and_b.x = R()
-    # Same for class objects
-    def inner3_class(a_and_b: Intersection[type[A3], type[B3]]):
-        # error: [possibly-unbound-attribute]
-        reveal_type(a_and_b.x)  # revealed: P & Q
-
-        # error: [possibly-unbound-attribute]
-        a_and_b.x = R()
-
-    class A4: ...
-    class B4: ...
-
-    def inner4(a_and_b: Intersection[A4, B4]):
-        # error: [unresolved-attribute]
-        reveal_type(a_and_b.x)  # revealed: Unknown
-
-        # error: [invalid-assignment]
-        a_and_b.x = R()
-    # Same for class objects
-    def inner4_class(a_and_b: Intersection[type[A4], type[B4]]):
-        # error: [unresolved-attribute]
-        reveal_type(a_and_b.x)  # revealed: Unknown
-
-        # error: [invalid-assignment]
-        a_and_b.x = R()
+    reveal_type(Bar.x)  # revealed: Unknown | Literal[2, 1]
 ```
 
-### Intersection of implicit instance attributes
+### Attribute possibly unbound on a subclass and on a superclass
 
 ```py
-from knot_extensions import Intersection
+def _(flag: bool):
+    class Foo:
+        if flag:
+            x = 1
 
-class P: ...
-class Q: ...
+    class Bar(Foo):
+        if flag:
+            x = 2
 
-class A:
-    def __init__(self):
-        self.x: P = P()
-
-class B:
-    def __init__(self):
-        self.x: Q = Q()
-
-def _(a_and_b: Intersection[A, B]):
-    reveal_type(a_and_b.x)  # revealed: P & Q
+    # error: [possibly-unbound-attribute]
+    reveal_type(Bar.x)  # revealed: Unknown | Literal[2, 1]
 ```
 
-## Attribute access on `Any`
+### Attribute access on `Any`
 
 The union of the set of types that `Any` could materialise to is equivalent to `object`. It follows
 from this that attribute access on `Any` resolves to `Any` if the attribute does not exist on
@@ -1303,112 +868,29 @@ reveal_type(C.__mro__)  # revealed: tuple[Literal[C], Literal[B], Any, Literal[A
 reveal_type(C.x)  # revealed: Literal[1] & Any
 ```
 
-## Classes with custom `__getattr__` methods
+### Unions with all paths unbound
 
-### Basic
-
-If a type provides a custom `__getattr__` method, we use the return type of that method as the type
-for unknown attributes. Consider the following `CustomGetAttr` class:
+If the symbol is unbound in all elements of the union, we detect that:
 
 ```py
-from typing import Literal
+def _(flag: bool):
+    class C1: ...
+    class C2: ...
+    C = C1 if flag else C2
 
-def flag() -> bool:
-    return True
-
-class GetAttrReturnType: ...
-
-class CustomGetAttr:
-    class_attr: int = 1
-
-    if flag():
-        possibly_unbound: bytes = b"a"
-
-    def __init__(self) -> None:
-        self.instance_attr: str = "a"
-
-    def __getattr__(self, name: str) -> GetAttrReturnType:
-        return GetAttrReturnType()
-```
-
-We can access arbitrary attributes on instances of this class, and the type of the attribute will be
-`GetAttrReturnType`:
-
-```py
-c = CustomGetAttr()
-
-reveal_type(c.whatever)  # revealed: GetAttrReturnType
-```
-
-If an attribute is defined on the class, it takes precedence over the `__getattr__` method:
-
-```py
-reveal_type(c.class_attr)  # revealed: int
-```
-
-If the class attribute is possibly unbound, we union the type of the attribute with the fallback
-type of the `__getattr__` method:
-
-```py
-reveal_type(c.possibly_unbound)  # revealed: bytes | GetAttrReturnType
-```
-
-Instance attributes also take precedence over the `__getattr__` method:
-
-```py
-# Note: we could attempt to union with the fallback type of `__getattr__` here, as we currently do not
-# attempt to determine if instance attributes are always bound or not. Neither mypy nor pyright do this,
-# so it's not a priority.
-reveal_type(c.instance_attr)  # revealed: str
-```
-
-### Type of the `name` parameter
-
-If the `name` parameter of the `__getattr__` method is annotated with a (union of) literal type(s),
-we only consider the attribute access to be valid if the accessed attribute is one of them:
-
-```py
-from typing import Literal
-
-class Date:
-    def __getattr__(self, name: Literal["day", "month", "year"]) -> int:
-        return 0
-
-date = Date()
-
-reveal_type(date.day)  # revealed: int
-reveal_type(date.month)  # revealed: int
-reveal_type(date.year)  # revealed: int
-
-# error: [unresolved-attribute] "Type `Date` has no attribute `century`"
-reveal_type(date.century)  # revealed: Unknown
-```
-
-### `argparse.Namespace`
-
-A standard library example of a class with a custom `__getattr__` method is `argparse.Namespace`:
-
-```py
-import argparse
-
-def _(ns: argparse.Namespace):
-    reveal_type(ns.whatever)  # revealed: Any
+    # error: [unresolved-attribute] "Type `Literal[C1, C2]` has no attribute `x`"
+    reveal_type(C.x)  # revealed: Unknown
 ```
 
 ## Objects of all types have a `__class__` method
 
-The type of `x.__class__` is the same as `x`'s meta-type. `x.__class__` is always the same value as
-`type(x)`.
-
 ```py
 import typing_extensions
 
 reveal_type(typing_extensions.__class__)  # revealed: Literal[ModuleType]
-reveal_type(type(typing_extensions))  # revealed: Literal[ModuleType]
 
 a = 42
 reveal_type(a.__class__)  # revealed: Literal[int]
-reveal_type(type(a))  # revealed: Literal[int]
 
 b = "42"
 reveal_type(b.__class__)  # revealed: Literal[str]
@@ -1424,13 +906,8 @@ reveal_type(e.__class__)  # revealed: Literal[tuple]
 
 def f(a: int, b: typing_extensions.LiteralString, c: int | str, d: type[str]):
     reveal_type(a.__class__)  # revealed: type[int]
-    reveal_type(type(a))  # revealed: type[int]
-
     reveal_type(b.__class__)  # revealed: Literal[str]
-    reveal_type(type(b))  # revealed: Literal[str]
-
     reveal_type(c.__class__)  # revealed: type[int] | type[str]
-    reveal_type(type(c))  # revealed: type[int] | type[str]
 
     # `type[type]`, a.k.a., either the class `type` or some subclass of `type`.
     # It would be incorrect to infer `Literal[type]` here,
@@ -1447,8 +924,6 @@ reveal_type(Foo.__class__)  # revealed: Literal[type]
 
 ## Module attributes
 
-### Basic
-
 `mod.py`:
 
 ```py
@@ -1483,7 +958,7 @@ for mod.global_symbol in IntIterable():
     pass
 ```
 
-### Nested module attributes
+## Nested attributes
 
 `outer/__init__.py`:
 
@@ -1541,7 +1016,7 @@ integers are instances of that class:
 
 ```py
 reveal_type((2).bit_length)  # revealed: <bound method `bit_length` of `Literal[2]`>
-reveal_type((2).denominator)  # revealed: Literal[1]
+reveal_type((2).denominator)  # revealed: @Todo(@property)
 ```
 
 Some attributes are special-cased, however:
@@ -1557,8 +1032,8 @@ Most attribute accesses on bool-literal types are delegated to `builtins.bool`,
 bools are instances of that class:
 
 ```py
-reveal_type(True.__and__)  # revealed: <bound method `__and__` of `Literal[True]`>
-reveal_type(False.__or__)  # revealed: <bound method `__or__` of `Literal[False]`>
+reveal_type(True.__and__)  # revealed: @Todo(decorated method)
+reveal_type(False.__or__)  # revealed: @Todo(decorated method)
 ```
 
 Some attributes are special-cased, however:
@@ -1661,20 +1136,6 @@ class C:
 reveal_type(C().x)  # revealed: Unknown
 ```
 
-### Accessing attributes on `Never`
-
-Arbitrary attributes can be accessed on `Never` without emitting any errors:
-
-```py
-from typing_extensions import Never
-
-def f(never: Never):
-    reveal_type(never.arbitrary_attribute)  # revealed: Never
-
-    # Assigning `Never` to an attribute on `Never` is also allowed:
-    never.another_attribute = never
-```
-
 ### Builtin types attributes
 
 This test can probably be removed eventually, but we currently include it because we do not yet
@@ -1709,43 +1170,11 @@ reveal_type(C.a_type)  # revealed: type
 reveal_type(C.a_none)  # revealed: None
 ```
 
-## Enum classes
-
-Enums are not supported yet; attribute access on an enum class is inferred as `Todo`.
-
-```py
-import enum
-
-reveal_type(enum.Enum.__members__)  # revealed: @Todo(Attribute access on enum classes)
-
-class Foo(enum.Enum):
-    BAR = 1
-
-reveal_type(Foo.BAR)  # revealed: @Todo(Attribute access on enum classes)
-reveal_type(Foo.BAR.value)  # revealed: @Todo(Attribute access on enum classes)
-reveal_type(Foo.__members__)  # revealed: @Todo(Attribute access on enum classes)
-```
-
-## `super()`
-
-`super()` is not supported yet, but we do not emit false positives on `super()` calls.
-
-```py
-class Foo:
-    def bar(self) -> int:
-        return 42
-
-class Bar(Foo):
-    def bar(self) -> int:
-        return super().bar()
-```
-
 ## References
 
 Some of the tests in the *Class and instance variables* section draw inspiration from
 [pyright's documentation] on this topic.
 
-[descriptor protocol tests]: descriptor_protocol.md
 [pyright's documentation]: https://microsoft.github.io/pyright/#/type-concepts-advanced?id=class-and-instance-variables
 [typing spec on `classvar`]: https://typing.readthedocs.io/en/latest/spec/class-compat.html#classvar
 [`typing.classvar`]: https://docs.python.org/3/library/typing.html#typing.ClassVar

crates/red_knot_python_semantic/resources/mdtest/binary/instances.md

@@ -14,43 +14,43 @@ We support inference for all Python's binary operators: `+`, `-`, `*`, `@`, `/`,
 
 ```py
 class A:
-    def __add__(self, other) -> "A":
+    def __add__(self, other) -> A:
         return self
 
-    def __sub__(self, other) -> "A":
+    def __sub__(self, other) -> A:
         return self
 
-    def __mul__(self, other) -> "A":
+    def __mul__(self, other) -> A:
         return self
 
-    def __matmul__(self, other) -> "A":
+    def __matmul__(self, other) -> A:
         return self
 
-    def __truediv__(self, other) -> "A":
+    def __truediv__(self, other) -> A:
         return self
 
-    def __floordiv__(self, other) -> "A":
+    def __floordiv__(self, other) -> A:
         return self
 
-    def __mod__(self, other) -> "A":
+    def __mod__(self, other) -> A:
         return self
 
-    def __pow__(self, other) -> "A":
+    def __pow__(self, other) -> A:
         return self
 
-    def __lshift__(self, other) -> "A":
+    def __lshift__(self, other) -> A:
         return self
 
-    def __rshift__(self, other) -> "A":
+    def __rshift__(self, other) -> A:
         return self
 
-    def __and__(self, other) -> "A":
+    def __and__(self, other) -> A:
         return self
 
-    def __xor__(self, other) -> "A":
+    def __xor__(self, other) -> A:
         return self
 
-    def __or__(self, other) -> "A":
+    def __or__(self, other) -> A:
         return self
 
 class B: ...
@@ -76,43 +76,43 @@ We also support inference for reflected operations:
 
 ```py
 class A:
-    def __radd__(self, other) -> "A":
+    def __radd__(self, other) -> A:
         return self
 
-    def __rsub__(self, other) -> "A":
+    def __rsub__(self, other) -> A:
         return self
 
-    def __rmul__(self, other) -> "A":
+    def __rmul__(self, other) -> A:
         return self
 
-    def __rmatmul__(self, other) -> "A":
+    def __rmatmul__(self, other) -> A:
         return self
 
-    def __rtruediv__(self, other) -> "A":
+    def __rtruediv__(self, other) -> A:
         return self
 
-    def __rfloordiv__(self, other) -> "A":
+    def __rfloordiv__(self, other) -> A:
         return self
 
-    def __rmod__(self, other) -> "A":
+    def __rmod__(self, other) -> A:
         return self
 
-    def __rpow__(self, other) -> "A":
+    def __rpow__(self, other) -> A:
         return self
 
-    def __rlshift__(self, other) -> "A":
+    def __rlshift__(self, other) -> A:
         return self
 
-    def __rrshift__(self, other) -> "A":
+    def __rrshift__(self, other) -> A:
         return self
 
-    def __rand__(self, other) -> "A":
+    def __rand__(self, other) -> A:
         return self
 
-    def __rxor__(self, other) -> "A":
+    def __rxor__(self, other) -> A:
         return self
 
-    def __ror__(self, other) -> "A":
+    def __ror__(self, other) -> A:
         return self
 
 class B: ...
@@ -157,11 +157,11 @@ the right-hand side is not a subtype of the left-hand side, `lhs.__add__` will t
 
 ```py
 class A:
-    def __add__(self, other: "B") -> int:
+    def __add__(self, other: B) -> int:
         return 42
 
 class B:
-    def __radd__(self, other: "A") -> str:
+    def __radd__(self, other: A) -> str:
         return "foo"
 
 reveal_type(A() + B())  # revealed:  int
@@ -169,10 +169,10 @@ reveal_type(A() + B())  # revealed:  int
 # Edge case: C is a subtype of C, *but* if the two sides are of *equal* types,
 # the lhs *still* takes precedence
 class C:
-    def __add__(self, other: "C") -> int:
+    def __add__(self, other: C) -> int:
         return 42
 
-    def __radd__(self, other: "C") -> str:
+    def __radd__(self, other: C) -> str:
         return "foo"
 
 reveal_type(C() + C())  # revealed: int
@@ -237,11 +237,11 @@ well.
 
 ```py
 class A:
-    def __sub__(self, other: "A") -> "A":
+    def __sub__(self, other: A) -> A:
         return A()
 
 class B:
-    def __rsub__(self, other: A) -> "B":
+    def __rsub__(self, other: A) -> B:
         return B()
 
 reveal_type(A() - B())  # revealed: B
@@ -259,17 +259,11 @@ class A:
 class B:
     __add__ = A()
 
-reveal_type(B() + B())  # revealed: Unknown | int
-```
-
-Note that we union with `Unknown` here because `__add__` is not declared. We do infer just `int` if
-the callable is declared:
-
-```py
-class B2:
-    __add__: A = A()
-
-reveal_type(B2() + B2())  # revealed: int
+# TODO: this could be `int` if we declare `B.__add__` using a `Callable` type
+# TODO: Should not be an error: `A` instance is not a method descriptor, don't prepend `self` arg.
+#   Revealed type should be `Unknown | int`.
+# error: [unsupported-operator] "Operator `+` is unsupported between objects of type `B` and `B`"
+reveal_type(B() + B())  # revealed: Unknown
 ```
 
 ## Integration test: numbers from typeshed
@@ -300,10 +294,10 @@ its instance super-type.
 
 ```py
 class A:
-    def __add__(self, other) -> "A":
+    def __add__(self, other) -> A:
         return self
 
-    def __radd__(self, other) -> "A":
+    def __radd__(self, other) -> A:
         return self
 
 reveal_type(A() + 1)  # revealed: A
@@ -312,7 +306,7 @@ reveal_type(1 + A())  # revealed: A
 reveal_type(A() + "foo")  # revealed: A
 # TODO should be `A` since `str.__add__` doesn't support `A` instances
 # TODO overloads
-reveal_type("foo" + A())  # revealed: @Todo(return type of overloaded function)
+reveal_type("foo" + A())  # revealed: @Todo(return type)
 
 reveal_type(A() + b"foo")  # revealed: A
 # TODO should be `A` since `bytes.__add__` doesn't support `A` instances
@@ -320,7 +314,7 @@ reveal_type(b"foo" + A())  # revealed: bytes
 
 reveal_type(A() + ())  # revealed: A
 # TODO this should be `A`, since `tuple.__add__` doesn't support `A` instances
-reveal_type(() + A())  # revealed: @Todo(return type of overloaded function)
+reveal_type(() + A())  # revealed: @Todo(return type)
 
 literal_string_instance = "foo" * 1_000_000_000
 # the test is not testing what it's meant to be testing if this isn't a `LiteralString`:
@@ -329,7 +323,7 @@ reveal_type(literal_string_instance)  # revealed: LiteralString
 reveal_type(A() + literal_string_instance)  # revealed: A
 # TODO should be `A` since `str.__add__` doesn't support `A` instances
 # TODO overloads
-reveal_type(literal_string_instance + A())  # revealed: @Todo(return type of overloaded function)
+reveal_type(literal_string_instance + A())  # revealed: @Todo(return type)
 ```
 
 ## Operations involving instances of classes inheriting from `Any`
@@ -357,53 +351,6 @@ class Y(Foo): ...
 reveal_type(X() + Y())  # revealed: int
 ```
 
-## Operations involving types with invalid `__bool__` methods
-
-<!-- snapshot-diagnostics -->
-
-```py
-class NotBoolable:
-    __bool__: int = 3
-
-a = NotBoolable()
-
-# error: [unsupported-bool-conversion]
-10 and a and True
-```
-
-## Operations on class objects
-
-When operating on class objects, the corresponding dunder methods are looked up on the metaclass.
-
-```py
-from __future__ import annotations
-
-class Meta(type):
-    def __add__(self, other: Meta) -> int:
-        return 1
-
-    def __lt__(self, other: Meta) -> bool:
-        return True
-
-    def __getitem__(self, key: int) -> str:
-        return "a"
-
-class A(metaclass=Meta): ...
-class B(metaclass=Meta): ...
-
-reveal_type(A + B)  # revealed: int
-# error: [unsupported-operator] "Operator `-` is unsupported between objects of type `Literal[A]` and `Literal[B]`"
-reveal_type(A - B)  # revealed: Unknown
-
-reveal_type(A < B)  # revealed: bool
-reveal_type(A > B)  # revealed: bool
-
-# error: [unsupported-operator] "Operator `<=` is not supported for types `Literal[A]` and `Literal[B]`"
-reveal_type(A <= B)  # revealed: Unknown
-
-reveal_type(A[0])  # revealed: str
-```
-
 ## Unsupported
 
 ### Dunder as instance attribute
@@ -439,12 +386,10 @@ A left-hand dunder method doesn't apply for the right-hand operand, or vice vers
 
 ```py
 class A:
-    def __add__(self, other) -> int:
-        return 1
+    def __add__(self, other) -> int: ...
 
 class B:
-    def __radd__(self, other) -> int:
-        return 1
+    def __radd__(self, other) -> int: ...
 
 class C: ...
 
@@ -466,7 +411,7 @@ the unreflected dunder of the left-hand operand. For context, see
 
 ```py
 class Foo:
-    def __radd__(self, other: "Foo") -> "Foo":
+    def __radd__(self, other: Foo) -> Foo:
         return self
 
 # error: [unsupported-operator]

crates/red_knot_python_semantic/resources/mdtest/binary/integers.md

@@ -10,7 +10,8 @@ reveal_type(-3 // 3)  # revealed: Literal[-1]
 reveal_type(-3 / 3)  # revealed: float
 reveal_type(5 % 3)  # revealed: Literal[2]
 
-# error: [unsupported-operator] "Operator `+` is unsupported between objects of type `Literal[2]` and `Literal["f"]`"
+# TODO: Should emit `unsupported-operator` but we don't understand the bases of `str`, so we think
+#       it inherits `Unknown`, so we think `str.__radd__` is `Unknown` instead of nonexistent.
 reveal_type(2 + "f")  # revealed: Unknown
 
 def lhs(x: int):
@@ -50,21 +51,9 @@ reveal_type(1 ** (largest_u32 + 1))  # revealed: int
 reveal_type(2**largest_u32)  # revealed: int
 
 def variable(x: int):
-    reveal_type(x**2)  # revealed: @Todo(return type of overloaded function)
-    reveal_type(2**x)  # revealed: @Todo(return type of overloaded function)
-    reveal_type(x**x)  # revealed: @Todo(return type of overloaded function)
-```
-
-If the second argument is \<0, a `float` is returned at runtime. If the first argument is \<0 but
-the second argument is >=0, an `int` is still returned:
-
-```py
-reveal_type(1**0)  # revealed: Literal[1]
-reveal_type(0**1)  # revealed: Literal[0]
-reveal_type(0**0)  # revealed: Literal[1]
-reveal_type((-1) ** 2)  # revealed: Literal[1]
-reveal_type(2 ** (-1))  # revealed: float
-reveal_type((-1) ** (-1))  # revealed: float
+    reveal_type(x**2)  # revealed: @Todo(return type)
+    reveal_type(2**x)  # revealed: @Todo(return type)
+    reveal_type(x**x)  # revealed: @Todo(return type)
 ```
 
 ## Division by Zero

crates/red_knot_python_semantic/resources/mdtest/binary/tuples.md

@@ -1,22 +0,0 @@
-# Binary operations on tuples
-
-## Concatenation for heterogeneous tuples
-
-```py
-reveal_type((1, 2) + (3, 4))  # revealed: tuple[Literal[1], Literal[2], Literal[3], Literal[4]]
-reveal_type(() + (1, 2))  # revealed: tuple[Literal[1], Literal[2]]
-reveal_type((1, 2) + ())  # revealed: tuple[Literal[1], Literal[2]]
-reveal_type(() + ())  # revealed: tuple[()]
-
-def _(x: tuple[int, str], y: tuple[None, tuple[int]]):
-    reveal_type(x + y)  # revealed: tuple[int, str, None, tuple[int]]
-    reveal_type(y + x)  # revealed: tuple[None, tuple[int], int, str]
-```
-
-## Concatenation for homogeneous tuples
-
-```py
-def _(x: tuple[int, ...], y: tuple[str, ...]):
-    reveal_type(x + y)  # revealed: @Todo(full tuple[...] support)
-    reveal_type(x + (1, 2))  # revealed: @Todo(full tuple[...] support)
-```

crates/red_knot_python_semantic/resources/mdtest/binary/unions.md

@@ -1,59 +0,0 @@
-# Binary operations on union types
-
-Binary operations on union types are only available if they are supported for all possible
-combinations of types:
-
-```py
-def f1(i: int, u: int | None):
-    # error: [unsupported-operator] "Operator `+` is unsupported between objects of type `int` and `int | None`"
-    reveal_type(i + u)  # revealed: Unknown
-    # error: [unsupported-operator] "Operator `+` is unsupported between objects of type `int | None` and `int`"
-    reveal_type(u + i)  # revealed: Unknown
-```
-
-`int` can be added to `int`, and `str` can be added to `str`, but expressions of type `int | str`
-cannot be added, because that would require addition of `int` and `str` or vice versa:
-
-```py
-def f2(i: int, s: str, int_or_str: int | str):
-    i + i
-    s + s
-    # error: [unsupported-operator] "Operator `+` is unsupported between objects of type `int | str` and `int | str`"
-    reveal_type(int_or_str + int_or_str)  # revealed: Unknown
-```
-
-However, if an operation is supported for all possible combinations, the result will be a union of
-the possible outcomes:
-
-```py
-from typing import Literal
-
-def f3(two_or_three: Literal[2, 3], a_or_b: Literal["a", "b"]):
-    reveal_type(two_or_three + two_or_three)  # revealed: Literal[4, 5, 6]
-    reveal_type(two_or_three**two_or_three)  # revealed: Literal[4, 8, 9, 27]
-
-    reveal_type(a_or_b + a_or_b)  # revealed: Literal["aa", "ab", "ba", "bb"]
-
-    reveal_type(two_or_three * a_or_b)  # revealed: Literal["aa", "bb", "aaa", "bbb"]
-```
-
-We treat a type annotation of `float` as a union of `int` and `float`, so union handling is relevant
-here:
-
-```py
-def f4(x: float, y: float):
-    reveal_type(x + y)  # revealed: int | float
-    reveal_type(x - y)  # revealed: int | float
-    reveal_type(x * y)  # revealed: int | float
-    reveal_type(x / y)  # revealed: int | float
-    reveal_type(x // y)  # revealed: int | float
-    reveal_type(x % y)  # revealed: int | float
-```
-
-If any of the union elements leads to a division by zero, we will report an error:
-
-```py
-def f5(m: int, n: Literal[-1, 0, 1]):
-    # error: [division-by-zero] "Cannot divide object of type `int` by zero"
-    return m / n
-```

crates/red_knot_python_semantic/resources/mdtest/boundness_declaredness/public.md

@@ -69,8 +69,7 @@ without raising an error.
 from typing import Any
 
 def any() -> Any: ...
-def flag() -> bool:
-    return True
+def flag() -> bool: ...
 
 a: int
 b: str
@@ -127,8 +126,7 @@ inferred types:
 from typing import Any
 
 def any() -> Any: ...
-def flag() -> bool:
-    return True
+def flag() -> bool: ...
 
 a = 1
 b = 2
@@ -166,8 +164,7 @@ error for both `a` and `b`:
 ```py
 from typing import Any
 
-def flag() -> bool:
-    return True
+def flag() -> bool: ...
 
 if flag():
     a: Any = 1
@@ -197,8 +194,7 @@ seems inconsistent when compared to the case just above.
 `mod.py`:
 
 ```py
-def flag() -> bool:
-    return True
+def flag() -> bool: ...
 
 if flag():
     a: int
@@ -252,8 +248,7 @@ inconsistent when compared to the "possibly-undeclared-and-possibly-unbound" cas
 `mod.py`:
 
 ```py
-def flag() -> bool:
-    return True
+def flag() -> bool: ...
 
 if flag:
     a = 1

crates/red_knot_python_semantic/resources/mdtest/call/annotation.md

@@ -1,43 +0,0 @@
-# `typing.Callable`
-
-```py
-from typing import Callable
-
-def _(c: Callable[[], int]):
-    reveal_type(c())  # revealed: int
-
-def _(c: Callable[[int, str], int]):
-    reveal_type(c(1, "a"))  # revealed: int
-
-    # error: [invalid-argument-type] "Object of type `Literal["a"]` cannot be assigned to parameter 1; expected type `int`"
-    # error: [invalid-argument-type] "Object of type `Literal[1]` cannot be assigned to parameter 2; expected type `str`"
-    reveal_type(c("a", 1))  # revealed: int
-```
-
-The `Callable` annotation can only be used to describe positional-only parameters.
-
-```py
-def _(c: Callable[[int, str], None]):
-    # error: [unknown-argument] "Argument `a` does not match any known parameter"
-    # error: [unknown-argument] "Argument `b` does not match any known parameter"
-    # error: [missing-argument] "No arguments provided for required parameters 1, 2"
-    reveal_type(c(a=1, b="b"))  # revealed: None
-```
-
-If the annotation uses a gradual form (`...`) for the parameter list, then it can accept any kind of
-parameter with any type.
-
-```py
-def _(c: Callable[..., int]):
-    reveal_type(c())  # revealed: int
-    reveal_type(c(1))  # revealed: int
-    reveal_type(c(1, "str", False, a=[1, 2], b=(3, 4)))  # revealed: int
-```
-
-An invalid `Callable` form can accept any parameters and will return `Unknown`.
-
-```py
-# error: [invalid-type-form]
-def _(c: Callable[42, str]):
-    reveal_type(c())  # revealed: Unknown
-```

crates/red_knot_python_semantic/resources/mdtest/call/builtins.md

@@ -1,79 +0,0 @@
-# Calling builtins
-
-## `bool` with incorrect arguments
-
-```py
-class NotBool:
-    __bool__ = None
-
-# error: [too-many-positional-arguments] "Too many positional arguments to class `bool`: expected 1, got 2"
-bool(1, 2)
-
-# TODO: We should emit an `unsupported-bool-conversion` error here because the argument doesn't implement `__bool__` correctly.
-bool(NotBool())
-```
-
-## Calls to `type()`
-
-A single-argument call to `type()` returns an object that has the argument's meta-type. (This is
-tested more extensively in `crates/red_knot_python_semantic/resources/mdtest/attributes.md`,
-alongside the tests for the `__class__` attribute.)
-
-```py
-reveal_type(type(1))  # revealed: Literal[int]
-```
-
-But a three-argument call to type creates a dynamic instance of the `type` class:
-
-```py
-reveal_type(type("Foo", (), {}))  # revealed: type
-```
-
-Other numbers of arguments are invalid
-
-```py
-# error: [no-matching-overload] "No overload of class `type` matches arguments"
-type("Foo", ())
-
-# error: [no-matching-overload] "No overload of class `type` matches arguments"
-type("Foo", (), {}, weird_other_arg=42)
-```
-
-## Calls to `str()`
-
-### Valid calls
-
-```py
-str()
-str("")
-str(b"")
-str(1)
-str(object=1)
-
-str(b"M\xc3\xbcsli", "utf-8")
-str(b"M\xc3\xbcsli", "utf-8", "replace")
-
-str(b"M\x00\xfc\x00s\x00l\x00i\x00", encoding="utf-16")
-str(b"M\x00\xfc\x00s\x00l\x00i\x00", encoding="utf-16", errors="ignore")
-
-str(bytearray.fromhex("4d c3 bc 73 6c 69"), "utf-8")
-str(bytearray(), "utf-8")
-
-str(encoding="utf-8", object=b"M\xc3\xbcsli")
-str(b"", errors="replace")
-str(encoding="utf-8")
-str(errors="replace")
-```
-
-### Invalid calls
-
-```py
-str(1, 2)  # error: [no-matching-overload]
-str(o=1)  # error: [no-matching-overload]
-
-# First argument is not a bytes-like object:
-str("Müsli", "utf-8")  # error: [no-matching-overload]
-
-# Second argument is not a valid encoding:
-str(b"M\xc3\xbcsli", b"utf-8")  # error: [no-matching-overload]
-```

crates/red_knot_python_semantic/resources/mdtest/call/callable_instance.md

@@ -25,8 +25,7 @@ reveal_type(b)  # revealed: Unknown
 def _(flag: bool):
     class PossiblyNotCallable:
         if flag:
-            def __call__(self) -> int:
-                return 1
+            def __call__(self) -> int: ...
 
     a = PossiblyNotCallable()
     result = a()  # error: "Object of type `PossiblyNotCallable` is not callable (possibly unbound `__call__` method)"
@@ -39,8 +38,7 @@ def _(flag: bool):
 def _(flag: bool):
     if flag:
         class PossiblyUnbound:
-            def __call__(self) -> int:
-                return 1
+            def __call__(self) -> int: ...
 
     # error: [possibly-unresolved-reference]
     a = PossiblyUnbound()
@@ -66,12 +64,11 @@ def _(flag: bool):
         if flag:
             __call__ = 1
         else:
-            def __call__(self) -> int:
-                return 1
+            def __call__(self) -> int: ...
 
     a = NonCallable()
     # error: [call-non-callable] "Object of type `Literal[1]` is not callable"
-    reveal_type(a())  # revealed: Unknown | int
+    reveal_type(a())  # revealed: int | Unknown
 ```
 
 ## Call binding errors
@@ -85,7 +82,7 @@ class C:
 
 c = C()
 
-# error: 15 [invalid-argument-type] "Object of type `Literal["foo"]` cannot be assigned to parameter 2 (`x`) of bound method `__call__`; expected type `int`"
+# error: 15 [invalid-argument-type] "Object of type `Literal["foo"]` cannot be assigned to parameter 2 (`x`) of function `__call__`; expected type `int`"
 reveal_type(c("foo"))  # revealed: int
 ```
 
@@ -99,7 +96,7 @@ class C:
 
 c = C()
 
-# error: 13 [invalid-argument-type] "Object of type `C` cannot be assigned to parameter 1 (`self`) of bound method `__call__`; expected type `int`"
+# error: 13 [invalid-argument-type] "Object of type `C` cannot be assigned to parameter 1 (`self`) of function `__call__`; expected type `int`"
 reveal_type(c())  # revealed: int
 ```
 

crates/red_knot_python_semantic/resources/mdtest/call/dunder.md

@@ -1,241 +0,0 @@
-# Dunder calls
-
-## Introduction
-
-This test suite explains and documents how dunder methods are looked up and called. Throughout the
-document, we use `__getitem__` as an example, but the same principles apply to other dunder methods.
-
-Dunder methods are implicitly called when using certain syntax. For example, the index operator
-`obj[key]` calls the `__getitem__` method under the hood. Exactly *how* a dunder method is looked up
-and called works slightly different from regular methods. Dunder methods are not looked up on `obj`
-directly, but rather on `type(obj)`. But in many ways, they still *act* as if they were called on
-`obj` directly. If the `__getitem__` member of `type(obj)` is a descriptor, it is called with `obj`
-as the `instance` argument to `__get__`. A desugared version of `obj[key]` is roughly equivalent to
-`getitem_desugared(obj, key)` as defined below:
-
-```py
-from typing import Any
-
-def find_name_in_mro(typ: type, name: str) -> Any:
-    # See implementation in https://docs.python.org/3/howto/descriptor.html#invocation-from-an-instance
-    pass
-
-def getitem_desugared(obj: object, key: object) -> object:
-    getitem_callable = find_name_in_mro(type(obj), "__getitem__")
-    if hasattr(getitem_callable, "__get__"):
-        getitem_callable = getitem_callable.__get__(obj, type(obj))
-
-    return getitem_callable(key)
-```
-
-In the following tests, we demonstrate that we implement this behavior correctly.
-
-## Operating on class objects
-
-If we invoke a dunder method on a class, it is looked up on the *meta* class, since any class is an
-instance of its metaclass:
-
-```py
-class Meta(type):
-    def __getitem__(cls, key: int) -> str:
-        return str(key)
-
-class DunderOnMetaclass(metaclass=Meta):
-    pass
-
-reveal_type(DunderOnMetaclass[0])  # revealed: str
-```
-
-If the dunder method is only present on the class itself, it will not be called:
-
-```py
-class ClassWithNormalDunder:
-    def __getitem__(self, key: int) -> str:
-        return str(key)
-
-# error: [non-subscriptable]
-ClassWithNormalDunder[0]
-```
-
-## Operating on instances
-
-When invoking a dunder method on an instance of a class, it is looked up on the class:
-
-```py
-class ClassWithNormalDunder:
-    def __getitem__(self, key: int) -> str:
-        return str(key)
-
-class_with_normal_dunder = ClassWithNormalDunder()
-
-reveal_type(class_with_normal_dunder[0])  # revealed: str
-```
-
-Which can be demonstrated by trying to attach a dunder method to an instance, which will not work:
-
-```py
-def external_getitem(instance, key: int) -> str:
-    return str(key)
-
-class ThisFails:
-    def __init__(self):
-        self.__getitem__ = external_getitem
-
-this_fails = ThisFails()
-
-# error: [non-subscriptable] "Cannot subscript object of type `ThisFails` with no `__getitem__` method"
-reveal_type(this_fails[0])  # revealed: Unknown
-```
-
-However, the attached dunder method *can* be called if accessed directly:
-
-```py
-reveal_type(this_fails.__getitem__(this_fails, 0))  # revealed: Unknown | str
-```
-
-The instance-level method is also not called when the class-level method is present:
-
-```py
-def external_getitem1(instance, key) -> str:
-    return "a"
-
-def external_getitem2(key) -> int:
-    return 1
-
-def _(flag: bool):
-    class ThisFails:
-        if flag:
-            __getitem__ = external_getitem1
-
-        def __init__(self):
-            self.__getitem__ = external_getitem2
-
-    this_fails = ThisFails()
-
-    # error: [call-possibly-unbound-method]
-    reveal_type(this_fails[0])  # revealed: Unknown | str
-```
-
-## When the dunder is not a method
-
-A dunder can also be a non-method callable:
-
-```py
-class SomeCallable:
-    def __call__(self, key: int) -> str:
-        return str(key)
-
-class ClassWithNonMethodDunder:
-    __getitem__: SomeCallable = SomeCallable()
-
-class_with_callable_dunder = ClassWithNonMethodDunder()
-
-reveal_type(class_with_callable_dunder[0])  # revealed: str
-```
-
-## Dunders are looked up using the descriptor protocol
-
-Here, we demonstrate that the descriptor protocol is invoked when looking up a dunder method. Note
-that the `instance` argument is on object of type `ClassWithDescriptorDunder`:
-
-```py
-from __future__ import annotations
-
-class SomeCallable:
-    def __call__(self, key: int) -> str:
-        return str(key)
-
-class Descriptor:
-    def __get__(self, instance: ClassWithDescriptorDunder, owner: type[ClassWithDescriptorDunder]) -> SomeCallable:
-        return SomeCallable()
-
-class ClassWithDescriptorDunder:
-    __getitem__: Descriptor = Descriptor()
-
-class_with_descriptor_dunder = ClassWithDescriptorDunder()
-
-reveal_type(class_with_descriptor_dunder[0])  # revealed: str
-```
-
-## Dunders can not be overwritten on instances
-
-If we attempt to overwrite a dunder method on an instance, it does not affect the behavior of
-implicit dunder calls:
-
-```py
-class C:
-    def __getitem__(self, key: int) -> str:
-        return str(key)
-
-    def f(self):
-        # TODO: This should emit an `invalid-assignment` diagnostic once we understand the type of `self`
-        self.__getitem__ = None
-
-# This is still fine, and simply calls the `__getitem__` method on the class
-reveal_type(C()[0])  # revealed: str
-```
-
-## Calling a union of dunder methods
-
-```py
-def _(flag: bool):
-    class C:
-        if flag:
-            def __getitem__(self, key: int) -> str:
-                return str(key)
-        else:
-            def __getitem__(self, key: int) -> bytes:
-                return bytes()
-
-    c = C()
-    reveal_type(c[0])  # revealed: str | bytes
-
-    if flag:
-        class D:
-            def __getitem__(self, key: int) -> str:
-                return str(key)
-
-    else:
-        class D:
-            def __getitem__(self, key: int) -> bytes:
-                return bytes()
-
-    d = D()
-    reveal_type(d[0])  # revealed: str | bytes
-```
-
-## Calling a union of types without dunder methods
-
-We add instance attributes here to make sure that we don't treat the implicit dunder calls here like
-regular method calls.
-
-```py
-def external_getitem(instance, key: int) -> str:
-    return str(key)
-
-class NotSubscriptable1:
-    def __init__(self, value: int):
-        self.__getitem__ = external_getitem
-
-class NotSubscriptable2:
-    def __init__(self, value: int):
-        self.__getitem__ = external_getitem
-
-def _(union: NotSubscriptable1 | NotSubscriptable2):
-    # error: [non-subscriptable]
-    union[0]
-```
-
-## Calling a possibly-unbound dunder method
-
-```py
-def _(flag: bool):
-    class C:
-        if flag:
-            def __getitem__(self, key: int) -> str:
-                return str(key)
-
-    c = C()
-    # error: [call-possibly-unbound-method]
-    reveal_type(c[0])  # revealed: str
-```

crates/red_knot_python_semantic/resources/mdtest/call/function.md

@@ -43,7 +43,8 @@ def decorator(func) -> Callable[[], int]:
 def bar() -> str:
     return "bar"
 
-reveal_type(bar())  # revealed: int
+# TODO: should reveal `int`, as the decorator replaces `bar` with `foo`
+reveal_type(bar())  # revealed: @Todo(return type)
 ```
 
 ## Invalid callable

crates/red_knot_python_semantic/resources/mdtest/call/getattr_static.md

@@ -12,7 +12,7 @@ import inspect
 
 class Descriptor:
     def __get__(self, instance, owner) -> str:
-        return "a"
+        return 1
 
 class C:
     normal: int = 1
@@ -59,7 +59,7 @@ import sys
 reveal_type(inspect.getattr_static(sys, "platform"))  # revealed: LiteralString
 reveal_type(inspect.getattr_static(inspect, "getattr_static"))  # revealed: Literal[getattr_static]
 
-reveal_type(inspect.getattr_static(1, "real"))  # revealed: property
+reveal_type(inspect.getattr_static(1, "real"))  # revealed: Literal[1]
 ```
 
 (Implicit) instance attributes can also be accessed through `inspect.getattr_static`:
@@ -72,23 +72,6 @@ class D:
 reveal_type(inspect.getattr_static(D(), "instance_attr"))  # revealed: int
 ```
 
-And attributes on metaclasses can be accessed when probing the class:
-
-```py
-class Meta(type):
-    attr: int = 1
-
-class E(metaclass=Meta): ...
-
-reveal_type(inspect.getattr_static(E, "attr"))  # revealed: int
-```
-
-Metaclass attributes can not be added when probing an instance of the class:
-
-```py
-reveal_type(inspect.getattr_static(E(), "attr", "non_existent"))  # revealed: Literal["non_existent"]
-```
-
 ## Error cases
 
 We can only infer precise types if the attribute is a literal string. In all other cases, we fall

crates/red_knot_python_semantic/resources/mdtest/call/methods.md

@@ -235,204 +235,24 @@ method_wrapper(C(), None)
 method_wrapper(None, C)
 
 # Passing `None` without an `owner` argument is an
-# error: [no-matching-overload] "No overload of method wrapper `__get__` of function `f` matches arguments"
+# error: [missing-argument] "No argument provided for required parameter `owner`"
 method_wrapper(None)
 
 # Passing something that is not assignable to `type` as the `owner` argument is an
-# error: [no-matching-overload] "No overload of method wrapper `__get__` of function `f` matches arguments"
+# error: [invalid-argument-type] "Object of type `Literal[1]` cannot be assigned to parameter 2 (`owner`); expected type `type`"
 method_wrapper(None, 1)
 
 # Passing `None` as the `owner` argument when `instance` is `None` is an
-# error: [no-matching-overload] "No overload of method wrapper `__get__` of function `f` matches arguments"
+# error: [invalid-argument-type] "Object of type `None` cannot be assigned to parameter 2 (`owner`); expected type `type`"
 method_wrapper(None, None)
 
 # Calling `__get__` without any arguments is an
-# error: [no-matching-overload] "No overload of method wrapper `__get__` of function `f` matches arguments"
+# error: [missing-argument] "No argument provided for required parameter `instance`"
 method_wrapper()
 
 # Calling `__get__` with too many positional arguments is an
-# error: [no-matching-overload] "No overload of method wrapper `__get__` of function `f` matches arguments"
+# error: [too-many-positional-arguments] "Too many positional arguments: expected 2, got 3"
 method_wrapper(C(), C, "one too many")
 ```
 
-## Fallback to metaclass
-
-When a method is accessed on a class object, it is looked up on the metaclass if it is not found on
-the class itself. This also creates a bound method that is bound to the class object itself:
-
-```py
-from __future__ import annotations
-
-class Meta(type):
-    def f(cls, arg: int) -> str:
-        return "a"
-
-class C(metaclass=Meta):
-    pass
-
-reveal_type(C.f)  # revealed: <bound method `f` of `Literal[C]`>
-reveal_type(C.f(1))  # revealed: str
-```
-
-The method `f` can not be accessed from an instance of the class:
-
-```py
-# error: [unresolved-attribute] "Type `C` has no attribute `f`"
-C().f
-```
-
-A metaclass function can be shadowed by a method on the class:
-
-```py
-from typing import Any, Literal
-
-class D(metaclass=Meta):
-    def f(arg: int) -> Literal["a"]:
-        return "a"
-
-reveal_type(D.f(1))  # revealed: Literal["a"]
-```
-
-If the class method is possibly unbound, we union the return types:
-
-```py
-def flag() -> bool:
-    return True
-
-class E(metaclass=Meta):
-    if flag():
-        def f(arg: int) -> Any:
-            return "a"
-
-reveal_type(E.f(1))  # revealed: str | Any
-```
-
-## `@classmethod`
-
-### Basic
-
-When a `@classmethod` attribute is accessed, it returns a bound method object, even when accessed on
-the class object itself:
-
-```py
-from __future__ import annotations
-
-class C:
-    @classmethod
-    def f(cls: type[C], x: int) -> str:
-        return "a"
-
-reveal_type(C.f)  # revealed: <bound method `f` of `Literal[C]`>
-reveal_type(C().f)  # revealed: <bound method `f` of `type[C]`>
-```
-
-The `cls` method argument is then implicitly passed as the first argument when calling the method:
-
-```py
-reveal_type(C.f(1))  # revealed: str
-reveal_type(C().f(1))  # revealed: str
-```
-
-When the class method is called incorrectly, we detect it:
-
-```py
-C.f("incorrect")  # error: [invalid-argument-type]
-C.f()  # error: [missing-argument]
-C.f(1, 2)  # error: [too-many-positional-arguments]
-```
-
-If the `cls` parameter is wrongly annotated, we emit an error at the call site:
-
-```py
-class D:
-    @classmethod
-    def f(cls: D):
-        # This function is wrongly annotated, it should be `type[D]` instead of `D`
-        pass
-
-# error: [invalid-argument-type] "Object of type `Literal[D]` cannot be assigned to parameter 1 (`cls`) of bound method `f`; expected type `D`"
-D.f()
-```
-
-When a class method is accessed on a derived class, it is bound to that derived class:
-
-```py
-class Derived(C):
-    pass
-
-reveal_type(Derived.f)  # revealed: <bound method `f` of `Literal[Derived]`>
-reveal_type(Derived().f)  # revealed: <bound method `f` of `type[Derived]`>
-
-reveal_type(Derived.f(1))  # revealed: str
-reveal_type(Derived().f(1))  # revealed: str
-```
-
-### Accessing the classmethod as a static member
-
-Accessing a `@classmethod`-decorated function at runtime returns a `classmethod` object. We
-currently don't model this explicitly:
-
-```py
-from inspect import getattr_static
-
-class C:
-    @classmethod
-    def f(cls): ...
-
-reveal_type(getattr_static(C, "f"))  # revealed: Literal[f]
-reveal_type(getattr_static(C, "f").__get__)  # revealed: <method-wrapper `__get__` of `f`>
-```
-
-But we correctly model how the `classmethod` descriptor works:
-
-```py
-reveal_type(getattr_static(C, "f").__get__(None, C))  # revealed: <bound method `f` of `Literal[C]`>
-reveal_type(getattr_static(C, "f").__get__(C(), C))  # revealed: <bound method `f` of `Literal[C]`>
-reveal_type(getattr_static(C, "f").__get__(C()))  # revealed: <bound method `f` of `type[C]`>
-```
-
-The `owner` argument takes precedence over the `instance` argument:
-
-```py
-reveal_type(getattr_static(C, "f").__get__("dummy", C))  # revealed: <bound method `f` of `Literal[C]`>
-```
-
-### Classmethods mixed with other decorators
-
-When a `@classmethod` is additionally decorated with another decorator, it is still treated as a
-class method:
-
-```py
-from __future__ import annotations
-
-def does_nothing[T](f: T) -> T:
-    return f
-
-class C:
-    @classmethod
-    # TODO: no error should be emitted here (needs support for generics)
-    # error: [invalid-argument-type]
-    @does_nothing
-    def f1(cls: type[C], x: int) -> str:
-        return "a"
-    # TODO: no error should be emitted here (needs support for generics)
-    # error: [invalid-argument-type]
-    @does_nothing
-    @classmethod
-    def f2(cls: type[C], x: int) -> str:
-        return "a"
-
-# TODO: All of these should be `str` (and not emit an error), once we support generics
-
-# error: [call-non-callable]
-reveal_type(C.f1(1))  # revealed: Unknown
-# error: [call-non-callable]
-reveal_type(C().f1(1))  # revealed: Unknown
-
-# error: [call-non-callable]
-reveal_type(C.f2(1))  # revealed: Unknown
-# error: [call-non-callable]
-reveal_type(C().f2(1))  # revealed: Unknown
-```
-
 [functions and methods]: https://docs.python.org/3/howto/descriptor.html#functions-and-methods

crates/red_knot_python_semantic/resources/mdtest/call/never.md

@@ -1,12 +0,0 @@
-# Never is callable
-
-The type `Never` is callable with an arbitrary set of arguments. The result is always `Never`.
-
-```py
-from typing_extensions import Never
-
-def f(never: Never):
-    reveal_type(never())  # revealed: Never
-    reveal_type(never(1))  # revealed: Never
-    reveal_type(never(1, "a", never, x=None))  # revealed: Never
-```

crates/red_knot_python_semantic/resources/mdtest/call/subclass_of.md

@@ -1,50 +0,0 @@
-# Call `type[...]`
-
-## Single class
-
-### Trivial constructor
-
-```py
-class C: ...
-
-def _(subclass_of_c: type[C]):
-    reveal_type(subclass_of_c())  # revealed: C
-```
-
-### Non-trivial constructor
-
-```py
-class C:
-    def __init__(self, x: int): ...
-
-def _(subclass_of_c: type[C]):
-    reveal_type(subclass_of_c(1))  # revealed: C
-
-    # TODO: Those should all be errors
-    reveal_type(subclass_of_c("a"))  # revealed: C
-    reveal_type(subclass_of_c())  # revealed: C
-    reveal_type(subclass_of_c(1, 2))  # revealed: C
-```
-
-## Dynamic base
-
-```py
-from typing import Any
-from knot_extensions import Unknown
-
-def _(subclass_of_any: type[Any], subclass_of_unknown: type[Unknown]):
-    reveal_type(subclass_of_any())  # revealed: Any
-    reveal_type(subclass_of_any("any", "args", 1, 2))  # revealed: Any
-    reveal_type(subclass_of_unknown())  # revealed: Unknown
-    reveal_type(subclass_of_unknown("any", "args", 1, 2))  # revealed: Unknown
-```
-
-## Unions of classes
-
-```py
-class A: ...
-class B: ...
-
-def _(subclass_of_ab: type[A | B]):
-    reveal_type(subclass_of_ab())  # revealed: A | B
-```

crates/red_knot_python_semantic/resources/mdtest/call/union.md

@@ -40,7 +40,7 @@ def _(flag: bool):
         def f() -> int:
             return 1
     x = f()  # error: [call-non-callable] "Object of type `Literal[1]` is not callable"
-    reveal_type(x)  # revealed: Unknown | int
+    reveal_type(x)  # revealed: int | Unknown
 ```
 
 ## Multiple non-callable elements in a union
@@ -56,9 +56,8 @@ def _(flag: bool, flag2: bool):
     else:
         def f() -> int:
             return 1
-    # TODO we should mention all non-callable elements of the union
     # error: [call-non-callable] "Object of type `Literal[1]` is not callable"
-    # revealed: Unknown | int
+    # revealed: int | Unknown
     reveal_type(f())
 ```
 
@@ -82,12 +81,8 @@ def _(flag: bool):
 Calling a union where the arguments don't match the signature of all variants.
 
 ```py
-def f1(a: int) -> int:
-    return a
-
-def f2(a: str) -> str:
-    return a
-
+def f1(a: int) -> int: ...
+def f2(a: str) -> str: ...
 def _(flag: bool):
     if flag:
         f = f1
@@ -113,65 +108,3 @@ def _(flag: bool):
     x = f(3)
     reveal_type(x)  # revealed: Unknown
 ```
-
-## Union of binding errors
-
-```py
-def f1(): ...
-def f2(): ...
-def _(flag: bool):
-    if flag:
-        f = f1
-    else:
-        f = f2
-
-    # TODO: we should show all errors from the union, not arbitrarily pick one union element
-    # error: [too-many-positional-arguments] "Too many positional arguments to function `f1`: expected 0, got 1"
-    x = f(3)
-    reveal_type(x)  # revealed: Unknown
-```
-
-## One not-callable, one wrong argument
-
-```py
-class C: ...
-
-def f1(): ...
-def _(flag: bool):
-    if flag:
-        f = f1
-    else:
-        f = C()
-
-    # TODO: we should either show all union errors here, or prioritize the not-callable error
-    # error: [too-many-positional-arguments] "Too many positional arguments to function `f1`: expected 0, got 1"
-    x = f(3)
-    reveal_type(x)  # revealed: Unknown
-```
-
-## Union including a special-cased function
-
-```py
-def _(flag: bool):
-    if flag:
-        f = str
-    else:
-        f = repr
-    reveal_type(str("string"))  # revealed: Literal["string"]
-    reveal_type(repr("string"))  # revealed: Literal["'string'"]
-    reveal_type(f("string"))  # revealed: Literal["string", "'string'"]
-```
-
-## Cannot use an argument as both a value and a type form
-
-```py
-from knot_extensions import is_fully_static
-
-def _(flag: bool):
-    if flag:
-        f = repr
-    else:
-        f = is_fully_static
-    # error: [conflicting-argument-forms] "Argument is used as both a value and a type form in call"
-    reveal_type(f(int))  # revealed: str | Literal[True]
-```

crates/red_knot_python_semantic/resources/mdtest/comparison/instances/membership_test.md

@@ -160,45 +160,3 @@ reveal_type(42 in A())  # revealed: bool
 # error: [unsupported-operator] "Operator `in` is not supported for types `str` and `A`, in comparing `Literal["hello"]` with `A`"
 reveal_type("hello" in A())  # revealed: bool
 ```
-
-## Return type that doesn't implement `__bool__` correctly
-
-`in` and `not in` operations will fail at runtime if the object on the right-hand side of the
-operation has a `__contains__` method that returns a type which is not convertible to `bool`. This
-is because of the way these operations are handled by the Python interpreter at runtime. If we
-assume that `y` is an object that has a `__contains__` method, the Python expression `x in y`
-desugars to a `contains(y, x)` call, where `contains` looks something like this:
-
-```ignore
-def contains(y, x):
-    return bool(type(y).__contains__(y, x))
-```
-
-where the `bool()` conversion itself implicitly calls `__bool__` under the hood.
-
-TODO: Ideally the message would explain to the user what's wrong. E.g,
-
-```ignore
-error: [operator] cannot use `in` operator on object of type `WithContains`
-    note: This is because the `in` operator implicitly calls `WithContains.__contains__`, but `WithContains.__contains__` is invalidly defined
-    note: `WithContains.__contains__` is invalidly defined because it returns an instance of `NotBoolable`, which cannot be evaluated in a boolean context
-    note: `NotBoolable` cannot be evaluated in a boolean context because its `__bool__` attribute is not callable
-```
-
-It may also be more appropriate to use `unsupported-operator` as the error code.
-
-<!-- snapshot-diagnostics -->
-
-```py
-class NotBoolable:
-    __bool__: int = 3
-
-class WithContains:
-    def __contains__(self, item) -> NotBoolable:
-        return NotBoolable()
-
-# error: [unsupported-bool-conversion]
-10 in WithContains()
-# error: [unsupported-bool-conversion]
-10 not in WithContains()
-```

crates/red_knot_python_semantic/resources/mdtest/comparison/instances/rich_comparison.md

@@ -154,7 +154,7 @@ reveal_type(B() >= A())  # revealed: LeReturnType
 
 class C:
     def __gt__(self, other: C) -> EqReturnType:
-        return EqReturnType()
+        return 42
 
     def __ge__(self, other: C) -> NeReturnType:
         return NeReturnType()
@@ -345,47 +345,3 @@ def f(x: bool, y: int):
     reveal_type(4.2 < x)  # revealed: bool
     reveal_type(x < 4.2)  # revealed: bool
 ```
-
-## Chained comparisons with objects that don't implement `__bool__` correctly
-
-<!-- snapshot-diagnostics -->
-
-Python implicitly calls `bool` on the comparison result of preceding elements (but not for the last
-element) of a chained comparison.
-
-```py
-class NotBoolable:
-    __bool__: int = 3
-
-class Comparable:
-    def __lt__(self, item) -> NotBoolable:
-        return NotBoolable()
-
-    def __gt__(self, item) -> NotBoolable:
-        return NotBoolable()
-
-# error: [unsupported-bool-conversion]
-10 < Comparable() < 20
-# error: [unsupported-bool-conversion]
-10 < Comparable() < Comparable()
-
-Comparable() < Comparable()  # fine
-```
-
-## Callables as comparison dunders
-
-```py
-from typing import Literal
-
-class AlwaysTrue:
-    def __call__(self, other: object) -> Literal[True]:
-        return True
-
-class A:
-    __eq__: AlwaysTrue = AlwaysTrue()
-    __lt__: AlwaysTrue = AlwaysTrue()
-
-reveal_type(A() == A())  # revealed: Literal[True]
-reveal_type(A() < A())  # revealed: Literal[True]
-reveal_type(A() > A())  # revealed: Literal[True]
-```

crates/red_knot_python_semantic/resources/mdtest/comparison/intersections.md

@@ -110,8 +110,7 @@ given operator:
 
 ```py
 class Container:
-    def __contains__(self, x) -> bool:
-        return False
+    def __contains__(self, x) -> bool: ...
 
 class NonContainer: ...
 
@@ -131,8 +130,7 @@ unsupported for the given operator:
 
 ```py
 class Container:
-    def __contains__(self, x) -> bool:
-        return False
+    def __contains__(self, x) -> bool: ...
 
 class NonContainer: ...
 

crates/red_knot_python_semantic/resources/mdtest/comparison/non_bool_returns.md

@@ -22,19 +22,14 @@ Walking through examples:
 from __future__ import annotations
 
 class A:
-    def __lt__(self, other) -> A:
-        return self
-
-    def __gt__(self, other) -> bool:
-        return False
+    def __lt__(self, other) -> A: ...
+    def __gt__(self, other) -> bool: ...
 
 class B:
-    def __lt__(self, other) -> B:
-        return self
+    def __lt__(self, other) -> B: ...
 
 class C:
-    def __lt__(self, other) -> C:
-        return self
+    def __lt__(self, other) -> C: ...
 
 x = A() < B() < C()
 reveal_type(x)  # revealed: A & ~AlwaysTruthy | B

crates/red_knot_python_semantic/resources/mdtest/comparison/tuples.md

@@ -197,7 +197,7 @@ class LtReturnTypeOnB: ...
 
 class B:
     def __lt__(self, o: B) -> LtReturnTypeOnB:
-        return LtReturnTypeOnB()
+        return set()
 
 reveal_type((A(), B()) < (A(), B()))  # revealed: LtReturnType | LtReturnTypeOnB | Literal[False]
 ```
@@ -334,61 +334,3 @@ reveal_type(a is not c)  # revealed: Literal[True]
 For tuples like `tuple[int, ...]`, `tuple[Any, ...]`
 
 // TODO
-
-## Chained comparisons with elements that incorrectly implement `__bool__`
-
-<!-- snapshot-diagnostics -->
-
-For an operation `A() < A()` to succeed at runtime, the `A.__lt__` method does not necessarily need
-to return an object that is convertible to a `bool`. However, the return type _does_ need to be
-convertible to a `bool` for the operation `A() < A() < A()` (a _chained_ comparison) to succeed.
-This is because `A() < A() < A()` desugars to something like this, which involves several implicit
-conversions to `bool`:
-
-```ignore
-def compute_chained_comparison():
-  a1 = A()
-  a2 = A()
-  first_comparison = a1 < a2
-  return first_comparison and (a2 < A())
-```
-
-```py
-class NotBoolable:
-    __bool__: int = 5
-
-class Comparable:
-    def __lt__(self, other) -> NotBoolable:
-        return NotBoolable()
-
-    def __gt__(self, other) -> NotBoolable:
-        return NotBoolable()
-
-a = (1, Comparable())
-b = (1, Comparable())
-
-# error: [unsupported-bool-conversion]
-a < b < b
-
-a < b  # fine
-```
-
-## Equality with elements that incorrectly implement `__bool__`
-
-<!-- snapshot-diagnostics -->
-
-Python does not generally attempt to coerce the result of `==` and `!=` operations between two
-arbitrary objects to a `bool`, but a comparison of tuples will fail if the result of comparing any
-pair of elements at equivalent positions cannot be converted to a `bool`:
-
-```py
-class NotBoolable:
-    __bool__: None = None
-
-class A:
-    def __eq__(self, other) -> NotBoolable:
-        return NotBoolable()
-
-# error: [unsupported-bool-conversion]
-(A(),) == (A(),)
-```

crates/red_knot_python_semantic/resources/mdtest/comprehensions/basic.md

@@ -104,8 +104,7 @@ class Iterator:
         return 42
 
 class Iterable:
-    def __iter__(self) -> Iterator:
-        return Iterator()
+    def __iter__(self) -> Iterator: ...
 
 # This is fine:
 x = [*Iterable()]

crates/red_knot_python_semantic/resources/mdtest/conditional/if_expression.md

@@ -35,13 +35,3 @@ def _(flag: bool):
     x = 1 if flag else None
     reveal_type(x)  # revealed: Literal[1] | None
 ```
-
-## Condition with object that implements `__bool__` incorrectly
-
-```py
-class NotBoolable:
-    __bool__: int = 3
-
-# error: [unsupported-bool-conversion] "Boolean conversion is unsupported for type `NotBoolable`; its `__bool__` method isn't callable"
-3 if NotBoolable() else 4
-```

crates/red_knot_python_semantic/resources/mdtest/conditional/if_statement.md

@@ -147,17 +147,3 @@ def _(flag: bool):
 
     reveal_type(y)  # revealed: Literal[0, 1]
 ```
-
-## Condition with object that implements `__bool__` incorrectly
-
-```py
-class NotBoolable:
-    __bool__: int = 3
-
-# error: [unsupported-bool-conversion] "Boolean conversion is unsupported for type `NotBoolable`; its `__bool__` method isn't callable"
-if NotBoolable():
-    ...
-# error: [unsupported-bool-conversion] "Boolean conversion is unsupported for type `NotBoolable`; its `__bool__` method isn't callable"
-elif NotBoolable():
-    ...
-```

crates/red_knot_python_semantic/resources/mdtest/conditional/match.md

@@ -43,255 +43,3 @@ def _(target: int):
 
     reveal_type(y)  # revealed: Literal[2, 3, 4]
 ```
-
-## Value match
-
-A value pattern matches based on equality: the first `case` branch here will be taken if `subject`
-is equal to `2`, even if `subject` is not an instance of `int`. We can't know whether `C` here has a
-custom `__eq__` implementation that might cause it to compare equal to `2`, so we have to consider
-the possibility that the `case` branch might be taken even though the type `C` is disjoint from the
-type `Literal[2]`.
-
-This leads us to infer `Literal[1, 3]` as the type of `y` after the `match` statement, rather than
-`Literal[1]`:
-
-```py
-from typing import final
-
-@final
-class C:
-    pass
-
-def _(subject: C):
-    y = 1
-    match subject:
-        case 2:
-            y = 3
-    reveal_type(y)  # revealed: Literal[1, 3]
-```
-
-## Class match
-
-A `case` branch with a class pattern is taken if the subject is an instance of the given class, and
-all subpatterns in the class pattern match.
-
-```py
-from typing import final
-
-class Foo:
-    pass
-
-class FooSub(Foo):
-    pass
-
-class Bar:
-    pass
-
-@final
-class Baz:
-    pass
-
-def _(target: FooSub):
-    y = 1
-
-    match target:
-        case Baz():
-            y = 2
-        case Foo():
-            y = 3
-        case Bar():
-            y = 4
-
-    reveal_type(y)  # revealed: Literal[3]
-
-def _(target: FooSub):
-    y = 1
-
-    match target:
-        case Baz():
-            y = 2
-        case Bar():
-            y = 3
-        case Foo():
-            y = 4
-
-    reveal_type(y)  # revealed: Literal[3, 4]
-
-def _(target: FooSub | str):
-    y = 1
-
-    match target:
-        case Baz():
-            y = 2
-        case Foo():
-            y = 3
-        case Bar():
-            y = 4
-
-    reveal_type(y)  # revealed: Literal[1, 3, 4]
-```
-
-## Singleton match
-
-Singleton patterns are matched based on identity, not equality comparisons or `isinstance()` checks.
-
-```py
-from typing import Literal
-
-def _(target: Literal[True, False]):
-    y = 1
-
-    match target:
-        case True:
-            y = 2
-        case False:
-            y = 3
-        case None:
-            y = 4
-
-    # TODO: with exhaustiveness checking, this should be Literal[2, 3]
-    reveal_type(y)  # revealed: Literal[1, 2, 3]
-
-def _(target: bool):
-    y = 1
-
-    match target:
-        case True:
-            y = 2
-        case False:
-            y = 3
-        case None:
-            y = 4
-
-    # TODO: with exhaustiveness checking, this should be Literal[2, 3]
-    reveal_type(y)  # revealed: Literal[1, 2, 3]
-
-def _(target: None):
-    y = 1
-
-    match target:
-        case True:
-            y = 2
-        case False:
-            y = 3
-        case None:
-            y = 4
-
-    reveal_type(y)  # revealed: Literal[4]
-
-def _(target: None | Literal[True]):
-    y = 1
-
-    match target:
-        case True:
-            y = 2
-        case False:
-            y = 3
-        case None:
-            y = 4
-
-    # TODO: with exhaustiveness checking, this should be Literal[2, 4]
-    reveal_type(y)  # revealed: Literal[1, 2, 4]
-
-# bool is an int subclass
-def _(target: int):
-    y = 1
-
-    match target:
-        case True:
-            y = 2
-        case False:
-            y = 3
-        case None:
-            y = 4
-
-    reveal_type(y)  # revealed: Literal[1, 2, 3]
-
-def _(target: str):
-    y = 1
-
-    match target:
-        case True:
-            y = 2
-        case False:
-            y = 3
-        case None:
-            y = 4
-
-    reveal_type(y)  # revealed: Literal[1]
-```
-
-## Or match
-
-A `|` pattern matches if any of the subpatterns match.
-
-```py
-from typing import Literal, final
-
-def _(target: Literal["foo", "baz"]):
-    y = 1
-
-    match target:
-        case "foo" | "bar":
-            y = 2
-        case "baz":
-            y = 3
-
-    # TODO: with exhaustiveness, this should be Literal[2, 3]
-    reveal_type(y)  # revealed: Literal[1, 2, 3]
-
-def _(target: None):
-    y = 1
-
-    match target:
-        case None | 3:
-            y = 2
-        case "foo" | 4 | True:
-            y = 3
-
-    reveal_type(y)  # revealed: Literal[2]
-
-@final
-class Baz:
-    pass
-
-def _(target: int | None | float):
-    y = 1
-
-    match target:
-        case None | 3:
-            y = 2
-        case Baz():
-            y = 3
-
-    reveal_type(y)  # revealed: Literal[1, 2]
-
-def _(target: None | str):
-    y = 1
-
-    match target:
-        case Baz() | True | False:
-            y = 2
-        case int():
-            y = 3
-
-    reveal_type(y)  # revealed: Literal[1, 3]
-```
-
-## Guard with object that implements `__bool__` incorrectly
-
-```py
-class NotBoolable:
-    __bool__: int = 3
-
-def _(target: int, flag: NotBoolable):
-    y = 1
-    match target:
-        # error: [unsupported-bool-conversion] "Boolean conversion is unsupported for type `NotBoolable`; its `__bool__` method isn't callable"
-        case 1 if flag:
-            y = 2
-        case 2:
-            y = 3
-
-    reveal_type(y)  # revealed: Literal[1, 2, 3]
-```

crates/red_knot_python_semantic/resources/mdtest/decorators.md

@@ -1,237 +0,0 @@
-# Decorators
-
-Decorators are a way to modify function and class behavior. A decorator is a callable that takes the
-function or class as an argument and returns a modified version of it.
-
-## Basic example
-
-A decorated function definition is conceptually similar to `def f(x): ...` followed by
-`f = decorator(f)`. This means that the type of a decorated function is the same as the return type
-of the decorator (which does not necessarily need to be a callable type):
-
-```py
-def custom_decorator(f) -> int:
-    return 1
-
-@custom_decorator
-def f(x): ...
-
-reveal_type(f)  # revealed: int
-```
-
-## Type-annotated decorator
-
-More commonly, a decorator returns a modified callable type:
-
-```py
-from typing import Callable
-
-def ensure_positive(wrapped: Callable[[int], bool]) -> Callable[[int], bool]:
-    return lambda x: wrapped(x) and x > 0
-
-@ensure_positive
-def even(x: int) -> bool:
-    return x % 2 == 0
-
-reveal_type(even)  # revealed: (int, /) -> bool
-reveal_type(even(4))  # revealed: bool
-```
-
-## Decorators which take arguments
-
-Decorators can be arbitrary expressions. This is often useful when the decorator itself takes
-arguments:
-
-```py
-from typing import Callable
-
-def ensure_larger_than(lower_bound: int) -> Callable[[Callable[[int], bool]], Callable[[int], bool]]:
-    def decorator(wrapped: Callable[[int], bool]) -> Callable[[int], bool]:
-        return lambda x: wrapped(x) and x >= lower_bound
-    return decorator
-
-@ensure_larger_than(10)
-def even(x: int) -> bool:
-    return x % 2 == 0
-
-reveal_type(even)  # revealed: (int, /) -> bool
-reveal_type(even(14))  # revealed: bool
-```
-
-## Multiple decorators
-
-Multiple decorators can be applied to a single function. They are applied in "bottom-up" order,
-meaning that the decorator closest to the function definition is applied first:
-
-```py
-def maps_to_str(f) -> str:
-    return "a"
-
-def maps_to_int(f) -> int:
-    return 1
-
-def maps_to_bytes(f) -> bytes:
-    return b"a"
-
-@maps_to_str
-@maps_to_int
-@maps_to_bytes
-def f(x): ...
-
-reveal_type(f)  # revealed: str
-```
-
-## Decorating with a class
-
-When a function is decorated with a class-based decorator, the decorated function turns into an
-instance of the class (see also: [properties](properties.md)). Attributes of the class can be
-accessed on the decorated function.
-
-```py
-class accept_strings:
-    custom_attribute: str = "a"
-
-    def __init__(self, f):
-        self.f = f
-
-    def __call__(self, x: str | int) -> bool:
-        return self.f(int(x))
-
-@accept_strings
-def even(x: int) -> bool:
-    return x > 0
-
-reveal_type(even)  # revealed: accept_strings
-reveal_type(even.custom_attribute)  # revealed: str
-reveal_type(even("1"))  # revealed: bool
-reveal_type(even(1))  # revealed: bool
-
-# error: [invalid-argument-type]
-even(None)
-```
-
-## Common decorator patterns
-
-### `functools.wraps`
-
-This test mainly makes sure that we do not emit any diagnostics in a case where the decorator is
-implemented using `functools.wraps`.
-
-```py
-from typing import Callable
-from functools import wraps
-
-def custom_decorator(f) -> Callable[[int], str]:
-    @wraps(f)
-    def wrapper(*args, **kwargs):
-        print("Calling decorated function")
-        return f(*args, **kwargs)
-    return wrapper
-
-@custom_decorator
-def f(x: int) -> str:
-    return str(x)
-
-reveal_type(f)  # revealed: (int, /) -> str
-```
-
-### `functools.cache`
-
-```py
-from functools import cache
-
-@cache
-def f(x: int) -> int:
-    return x**2
-
-# TODO: Should be `_lru_cache_wrapper[int]`
-reveal_type(f)  # revealed: @Todo(generics)
-
-# TODO: Should be `int`
-reveal_type(f(1))  # revealed: @Todo(generics)
-```
-
-## Lambdas as decorators
-
-```py
-@lambda f: f
-def g(x: int) -> str:
-    return "a"
-
-# TODO: This should be `Literal[g]` or `(int, /) -> str`
-reveal_type(g)  # revealed: Unknown
-```
-
-## Error cases
-
-### Unknown decorator
-
-```py
-# error: [unresolved-reference] "Name `unknown_decorator` used when not defined"
-@unknown_decorator
-def f(x): ...
-
-reveal_type(f)  # revealed: Unknown
-```
-
-### Error in the decorator expression
-
-```py
-# error: [unsupported-operator]
-@(1 + "a")
-def f(x): ...
-
-reveal_type(f)  # revealed: Unknown
-```
-
-### Non-callable decorator
-
-```py
-non_callable = 1
-
-# error: [call-non-callable] "Object of type `Literal[1]` is not callable"
-@non_callable
-def f(x): ...
-
-reveal_type(f)  # revealed: Unknown
-```
-
-### Wrong signature
-
-#### Wrong argument type
-
-Here, we emit a diagnostic since `wrong_signature` takes an `int` instead of a callable type as the
-first argument:
-
-```py
-def wrong_signature(f: int) -> str:
-    return "a"
-
-# error: [invalid-argument-type] "Object of type `Literal[f]` cannot be assigned to parameter 1 (`f`) of function `wrong_signature`; expected type `int`"
-@wrong_signature
-def f(x): ...
-
-reveal_type(f)  # revealed: str
-```
-
-#### Wrong number of arguments
-
-Decorators need to be callable with a single argument. If they are not, we emit a diagnostic:
-
-```py
-def takes_two_arguments(f, g) -> str:
-    return "a"
-
-# error: [missing-argument] "No argument provided for required parameter `g` of function `takes_two_arguments`"
-@takes_two_arguments
-def f(x): ...
-
-reveal_type(f)  # revealed: str
-
-def takes_no_argument() -> str:
-    return "a"
-
-# error: [too-many-positional-arguments] "Too many positional arguments to function `takes_no_argument`: expected 0, got 1"
-@takes_no_argument
-def g(x): ...
-```

crates/red_knot_python_semantic/resources/mdtest/descriptor_protocol.md

@@ -6,9 +6,7 @@ A descriptor is an attribute value that has one of the methods in the descriptor
 methods are `__get__()`, `__set__()`, and `__delete__()`. If any of those methods are defined for an
 attribute, it is said to be a descriptor.
 
-## Basic properties
-
-### Example
+## Basic example
 
 An introductory example, modeled after a [simple example] in the primer on descriptors, involving a
 descriptor that returns a constant value:
@@ -32,26 +30,22 @@ reveal_type(c.ten)  # revealed: Literal[10]
 
 reveal_type(C.ten)  # revealed: Literal[10]
 
-# This is fine:
-c.ten = 10
-
-# error: [invalid-assignment] "Invalid assignment to data descriptor attribute `ten` on type `C` with custom `__set__` method"
-c.ten = 11
-```
-
-When assigning to the `ten` attribute from the class object, we get an error. The descriptor
-protocol is *not* triggered in this case. Since the attribute is declared as `Ten` in the class
-body, we do not allow these assignments, preventing users from accidentally overwriting the data
-descriptor, which is what would happen at runtime:
-
-```py
-# error: [invalid-assignment] "Object of type `Literal[10]` is not assignable to attribute `ten` of type `Ten`"
+# These are fine:
+# TODO: This should not be an error
+c.ten = 10  # error: [invalid-assignment]
 C.ten = 10
+
+# TODO: This should be an error (as the wrong type is being implicitly passed to `Ten.__set__`),
+# but the error message is misleading.
 # error: [invalid-assignment] "Object of type `Literal[11]` is not assignable to attribute `ten` of type `Ten`"
+c.ten = 11
+
+# TODO: same as above
+# error: [invalid-assignment] "Object of type `Literal[11]` is not assignable to attribute `ten` of type `Literal[10]`"
 C.ten = 11
 ```
 
-### Different types for `__get__` and `__set__`
+## Different types for `__get__` and `__set__`
 
 The return type of `__get__` and the value type of `__set__` can be different:
 
@@ -73,23 +67,28 @@ c = C()
 
 reveal_type(c.flexible_int)  # revealed: int | None
 
+# TODO: These should not be errors
+# error: [invalid-assignment]
 c.flexible_int = 42  # okay
+# error: [invalid-assignment]
 c.flexible_int = "42"  # also okay!
 
 reveal_type(c.flexible_int)  # revealed: int | None
 
-# error: [invalid-assignment] "Invalid assignment to data descriptor attribute `flexible_int` on type `C` with custom `__set__` method"
+# TODO: This should be an error, but the message needs to be improved.
+# error: [invalid-assignment] "Object of type `None` is not assignable to attribute `flexible_int` of type `FlexibleInt`"
 c.flexible_int = None  # not okay
 
 reveal_type(c.flexible_int)  # revealed: int | None
 ```
 
-### Data and non-data descriptors
+## Data and non-data descriptors
 
-Descriptors that define `__set__` or `__delete__` are called *data descriptors*. An example of a
-data descriptor is a `property` with a setter and/or a deleter. Descriptors that only define
-`__get__`, meanwhile, are called *non-data descriptors*. Examples include functions, `classmethod`
-or `staticmethod`.
+Descriptors that define `__set__` or `__delete__` are called *data descriptors*. An example\
+of a data descriptor is a `property` with a setter and/or a deleter.\
+Descriptors that only define `__get__`, meanwhile, are called *non-data descriptors*. Examples
+include\
+functions, `classmethod` or `staticmethod`).
 
 The precedence chain for attribute access is (1) data descriptors, (2) instance attributes, and (3)
 non-data descriptors.
@@ -101,7 +100,7 @@ class DataDescriptor:
     def __get__(self, instance: object, owner: type | None = None) -> Literal["data"]:
         return "data"
 
-    def __set__(self, instance: object, value: int) -> None:
+    def __set__(self, instance: int, value) -> None:
         pass
 
 class NonDataDescriptor:
@@ -125,7 +124,12 @@ class C:
 
 c = C()
 
-reveal_type(c.data_descriptor)  # revealed: Unknown | Literal["data"]
+# TODO: This should ideally be `Unknown | Literal["data"]`.
+#
+#     - Pyright also wrongly shows `int | Literal['data']` here
+#     - Mypy shows Literal["data"] here, but also shows Literal["non-data"] below.
+#
+reveal_type(c.data_descriptor)  # revealed: Unknown | Literal["data", 1]
 
 reveal_type(c.non_data_descriptor)  # revealed: Unknown | Literal["non-data", 1]
 
@@ -139,63 +143,79 @@ reveal_type(C.non_data_descriptor)  # revealed: Unknown | Literal["non-data"]
 C.data_descriptor = "something else"  # This is okay
 ```
 
-### Partial fall back
+## Built-in `property` descriptor
 
-Our implementation of the descriptor protocol takes into account that symbols can be possibly
-unbound. In those cases, we fall back to lower precedence steps of the descriptor protocol and union
-all possible results accordingly. We start by defining a data and a non-data descriptor:
+The built-in `property` decorator creates a descriptor. The names for attribute reads/writes are
+determined by the return type of the `name` method and the parameter type of the setter,
+respectively.
 
 ```py
-from typing import Literal
+class C:
+    _name: str | None = None
 
-class DataDescriptor:
-    def __get__(self, instance: object, owner: type | None = None) -> Literal["data"]:
-        return "data"
+    @property
+    def name(self) -> str:
+        return self._name or "Unset"
+    # TODO: No diagnostic should be emitted here
+    # error: [unresolved-attribute] "Type `Literal[name]` has no attribute `setter`"
+    @name.setter
+    def name(self, value: str | None) -> None:
+        self._value = value
 
-    def __set__(self, instance: object, value: int) -> None:
-        pass
+c = C()
 
-class NonDataDescriptor:
-    def __get__(self, instance: object, owner: type | None = None) -> Literal["non-data"]:
-        return "non-data"
+reveal_type(c._name)  # revealed: str | None
+
+# Should be `str`
+reveal_type(c.name)  # revealed: @Todo(decorated method)
+
+# Should be `builtins.property`
+reveal_type(C.name)  # revealed: Literal[name]
+
+# This is fine:
+c.name = "new"
+
+c.name = None
+
+# TODO: this should be an error
+c.name = 42
 ```
 
-Then, we demonstrate that we fall back to an instance attribute if a data descriptor is possibly
-unbound:
+## Built-in `classmethod` descriptor
+
+Similarly to `property`, `classmethod` decorator creates an implicit descriptor that binds the first
+argument to the class instead of the instance.
 
 ```py
-def f1(flag: bool):
-    class C1:
-        if flag:
-            attr = DataDescriptor()
+class C:
+    def __init__(self, value: str) -> None:
+        self._name: str = value
 
-        def f(self):
-            self.attr = "normal"
+    @classmethod
+    def factory(cls, value: str) -> "C":
+        return cls(value)
 
-    reveal_type(C1().attr)  # revealed: Unknown | Literal["data", "normal"]
+    @classmethod
+    def get_name(cls) -> str:
+        return cls.__name__
 
-    # Assigning to the attribute also causes no `possibly-unbound` diagnostic:
-    C1().attr = 1
+c1 = C.factory("test")  # okay
+
+# TODO: should be `C`
+reveal_type(c1)  # revealed: @Todo(return type)
+
+# TODO: should be `str`
+reveal_type(C.get_name())  # revealed: @Todo(return type)
+
+# TODO: should be `str`
+reveal_type(C("42").get_name())  # revealed: @Todo(decorated method)
 ```
 
-We never treat implicit instance attributes as definitely bound, so we fall back to the non-data
-descriptor here:
+## Descriptors only work when used as class variables
 
-```py
-class C2:
-    def f(self):
-        self.attr = "normal"
-    attr = NonDataDescriptor()
+From the descriptor guide:
 
-reveal_type(C2().attr)  # revealed: Unknown | Literal["non-data", "normal"]
-
-# Assignments always go to the instance attribute in this case
-C2().attr = 1
-```
-
-### Descriptors only work when used as class variables
-
-Descriptors only work when used as class variables. When put in instances, they have no effect.
+> Descriptors only work when used as class variables. When put in instances, they have no effect.
 
 ```py
 from typing import Literal
@@ -208,232 +228,8 @@ class C:
     def __init__(self):
         self.ten: Ten = Ten()
 
-reveal_type(C().ten)  # revealed: Ten
-
-C().ten = Ten()
-
-# The instance attribute is declared as `Ten`, so this is an
-# error: [invalid-assignment] "Object of type `Literal[10]` is not assignable to attribute `ten` of type `Ten`"
-C().ten = 10
-```
-
-## Descriptor protocol for class objects
-
-When attributes are accessed on a class object, the following [precedence chain] is used:
-
-- Data descriptor on the metaclass
-- Data or non-data descriptor on the class
-- Class attribute
-- Non-data descriptor on the metaclass
-- Metaclass attribute
-
-To verify this, we define a data and a non-data descriptor:
-
-```py
-from typing import Literal, Any
-
-class DataDescriptor:
-    def __get__(self, instance: object, owner: type | None = None) -> Literal["data"]:
-        return "data"
-
-    def __set__(self, instance: object, value: int) -> None:
-        pass
-
-class NonDataDescriptor:
-    def __get__(self, instance: object, owner: type | None = None) -> Literal["non-data"]:
-        return "non-data"
-```
-
-First, we make sure that the descriptors are correctly accessed when defined on the metaclass or the
-class:
-
-```py
-class Meta1(type):
-    meta_data_descriptor: DataDescriptor = DataDescriptor()
-    meta_non_data_descriptor: NonDataDescriptor = NonDataDescriptor()
-
-class C1(metaclass=Meta1):
-    class_data_descriptor: DataDescriptor = DataDescriptor()
-    class_non_data_descriptor: NonDataDescriptor = NonDataDescriptor()
-
-reveal_type(C1.meta_data_descriptor)  # revealed: Literal["data"]
-reveal_type(C1.meta_non_data_descriptor)  # revealed: Literal["non-data"]
-
-reveal_type(C1.class_data_descriptor)  # revealed: Literal["data"]
-reveal_type(C1.class_non_data_descriptor)  # revealed: Literal["non-data"]
-```
-
-Assignments to class object attribute only trigger the descriptor protocol if the data descriptor is
-on the metaclass:
-
-```py
-C1.meta_data_descriptor = 1
-
-# error: [invalid-assignment] "Invalid assignment to data descriptor attribute `meta_data_descriptor` on type `Literal[C1]` with custom `__set__` method"
-C1.meta_data_descriptor = "invalid"
-```
-
-When writing to a class-level data descriptor from the class object itself, the descriptor protocol
-is *not* triggered (this is in contrast to what happens when you read class-level descriptor
-attributes!). So the following assignment does not call `__set__`. At runtime, the assignment would
-overwrite the data descriptor, but the attribute is declared as `DataDescriptor` in the class body,
-so we do not allow this:
-
-```py
-# error: [invalid-assignment] "Object of type `Literal[1]` is not assignable to attribute `class_data_descriptor` of type `DataDescriptor`"
-C1.class_data_descriptor = 1
-```
-
-We now demonstrate that a *metaclass data descriptor* takes precedence over all class-level
-attributes:
-
-```py
-class Meta2(type):
-    meta_data_descriptor1: DataDescriptor = DataDescriptor()
-    meta_data_descriptor2: DataDescriptor = DataDescriptor()
-
-class ClassLevelDataDescriptor:
-    def __get__(self, instance: object, owner: type | None = None) -> Literal["class level data descriptor"]:
-        return "class level data descriptor"
-
-    def __set__(self, instance: object, value: str) -> None:
-        pass
-
-class C2(metaclass=Meta2):
-    meta_data_descriptor1: Literal["value on class"] = "value on class"
-    meta_data_descriptor2: ClassLevelDataDescriptor = ClassLevelDataDescriptor()
-
-reveal_type(C2.meta_data_descriptor1)  # revealed: Literal["data"]
-reveal_type(C2.meta_data_descriptor2)  # revealed: Literal["data"]
-
-C2.meta_data_descriptor1 = 1
-C2.meta_data_descriptor2 = 1
-
-# error: [invalid-assignment]
-C2.meta_data_descriptor1 = "invalid"
-# error: [invalid-assignment]
-C2.meta_data_descriptor2 = "invalid"
-```
-
-On the other hand, normal metaclass attributes and metaclass non-data descriptors are shadowed by
-class-level attributes (descriptor or not):
-
-```py
-class Meta3(type):
-    meta_attribute1: Literal["value on metaclass"] = "value on metaclass"
-    meta_attribute2: Literal["value on metaclass"] = "value on metaclass"
-    meta_non_data_descriptor1: NonDataDescriptor = NonDataDescriptor()
-    meta_non_data_descriptor2: NonDataDescriptor = NonDataDescriptor()
-
-class C3(metaclass=Meta3):
-    meta_attribute1: Literal["value on class"] = "value on class"
-    meta_attribute2: ClassLevelDataDescriptor = ClassLevelDataDescriptor()
-    meta_non_data_descriptor1: Literal["value on class"] = "value on class"
-    meta_non_data_descriptor2: ClassLevelDataDescriptor = ClassLevelDataDescriptor()
-
-reveal_type(C3.meta_attribute1)  # revealed: Literal["value on class"]
-reveal_type(C3.meta_attribute2)  # revealed: Literal["class level data descriptor"]
-reveal_type(C3.meta_non_data_descriptor1)  # revealed: Literal["value on class"]
-reveal_type(C3.meta_non_data_descriptor2)  # revealed: Literal["class level data descriptor"]
-```
-
-Finally, metaclass attributes and metaclass non-data descriptors are only accessible when they are
-not shadowed by class-level attributes:
-
-```py
-class Meta4(type):
-    meta_attribute: Literal["value on metaclass"] = "value on metaclass"
-    meta_non_data_descriptor: NonDataDescriptor = NonDataDescriptor()
-
-class C4(metaclass=Meta4): ...
-
-reveal_type(C4.meta_attribute)  # revealed: Literal["value on metaclass"]
-reveal_type(C4.meta_non_data_descriptor)  # revealed: Literal["non-data"]
-```
-
-When a metaclass data descriptor is possibly unbound, we union the result type of its `__get__`
-method with an underlying class level attribute, if present:
-
-```py
-def _(flag: bool):
-    class Meta5(type):
-        if flag:
-            meta_data_descriptor1: DataDescriptor = DataDescriptor()
-            meta_data_descriptor2: DataDescriptor = DataDescriptor()
-
-    class C5(metaclass=Meta5):
-        meta_data_descriptor1: Literal["value on class"] = "value on class"
-
-    reveal_type(C5.meta_data_descriptor1)  # revealed: Literal["data", "value on class"]
-    # error: [possibly-unbound-attribute]
-    reveal_type(C5.meta_data_descriptor2)  # revealed: Literal["data"]
-
-    # TODO: We currently emit two diagnostics here, corresponding to the two states of `flag`. The diagnostics are not
-    # wrong, but they could be subsumed under a higher-level diagnostic.
-
-    # error: [invalid-assignment] "Invalid assignment to data descriptor attribute `meta_data_descriptor1` on type `Literal[C5]` with custom `__set__` method"
-    # error: [invalid-assignment] "Object of type `None` is not assignable to attribute `meta_data_descriptor1` of type `Literal["value on class"]`"
-    C5.meta_data_descriptor1 = None
-
-    # error: [possibly-unbound-attribute]
-    C5.meta_data_descriptor2 = 1
-```
-
-When a class-level attribute is possibly unbound, we union its (descriptor protocol) type with the
-metaclass attribute (unless it's a data descriptor, which always takes precedence):
-
-```py
-from typing import Any
-
-def _(flag: bool):
-    class Meta6(type):
-        attribute1: DataDescriptor = DataDescriptor()
-        attribute2: NonDataDescriptor = NonDataDescriptor()
-        attribute3: Literal["value on metaclass"] = "value on metaclass"
-
-    class C6(metaclass=Meta6):
-        if flag:
-            attribute1: Literal["value on class"] = "value on class"
-            attribute2: Literal["value on class"] = "value on class"
-            attribute3: Literal["value on class"] = "value on class"
-            attribute4: Literal["value on class"] = "value on class"
-
-    reveal_type(C6.attribute1)  # revealed: Literal["data"]
-    reveal_type(C6.attribute2)  # revealed: Literal["non-data", "value on class"]
-    reveal_type(C6.attribute3)  # revealed: Literal["value on metaclass", "value on class"]
-    # error: [possibly-unbound-attribute]
-    reveal_type(C6.attribute4)  # revealed: Literal["value on class"]
-```
-
-Finally, we can also have unions of various types of attributes:
-
-```py
-def _(flag: bool):
-    class Meta7(type):
-        if flag:
-            union_of_metaclass_attributes: Literal[1] = 1
-            union_of_metaclass_data_descriptor_and_attribute: DataDescriptor = DataDescriptor()
-        else:
-            union_of_metaclass_attributes: Literal[2] = 2
-            union_of_metaclass_data_descriptor_and_attribute: Literal[2] = 2
-
-    class C7(metaclass=Meta7):
-        if flag:
-            union_of_class_attributes: Literal[1] = 1
-            union_of_class_data_descriptor_and_attribute: DataDescriptor = DataDescriptor()
-        else:
-            union_of_class_attributes: Literal[2] = 2
-            union_of_class_data_descriptor_and_attribute: Literal[2] = 2
-
-    reveal_type(C7.union_of_metaclass_attributes)  # revealed: Literal[1, 2]
-    reveal_type(C7.union_of_metaclass_data_descriptor_and_attribute)  # revealed: Literal["data", 2]
-    reveal_type(C7.union_of_class_attributes)  # revealed: Literal[1, 2]
-    reveal_type(C7.union_of_class_data_descriptor_and_attribute)  # revealed: Literal["data", 2]
-
-    C7.union_of_metaclass_attributes = 2 if flag else 1
-    C7.union_of_metaclass_data_descriptor_and_attribute = 2 if flag else 100
-    C7.union_of_class_attributes = 2 if flag else 1
-    C7.union_of_class_data_descriptor_and_attribute = 2 if flag else DataDescriptor()
+# TODO: Should be Ten
+reveal_type(C().ten)  # revealed: Literal[10]
 ```
 
 ## Descriptors distinguishing between class and instance access
@@ -466,12 +262,63 @@ reveal_type(C.d)  # revealed: LiteralString
 reveal_type(C().d)  # revealed: LiteralString
 ```
 
-## Descriptor protocol for dunder methods
+## Undeclared descriptor arguments
 
-Dunder methods are always looked up on the meta-type. There is no instance fallback. This means that
-an implicit dunder call on an instance-like object will not only look up the dunder method on the
-class object, without considering instance attributes. And an implicit dunder call on a class object
-will look up the dunder method on the metaclass, without considering class attributes.
+If a descriptor attribute is not declared, we union with `Unknown`, just like for regular
+attributes, since that attribute could be overwritten externally. Even a data descriptor with a
+`__set__` method can be overwritten when accessed through a class object.
+
+```py
+class Descriptor:
+    def __get__(self, instance: object, owner: type | None = None) -> int:
+        return 1
+
+    def __set__(self, instance: object, value: int) -> None:
+        pass
+
+class C:
+    descriptor = Descriptor()
+
+C.descriptor = "something else"
+
+# This could also be `Literal["something else"]` if we support narrowing of attribute types based on assignments
+reveal_type(C.descriptor)  # revealed: Unknown | int
+```
+
+## Descriptors with incorrect `__get__` signature
+
+```py
+class Descriptor:
+    # `__get__` method with missing parameters:
+    def __get__(self) -> int:
+        return 1
+
+class C:
+    descriptor: Descriptor = Descriptor()
+
+# TODO: This should be an error
+reveal_type(C.descriptor)  # revealed: Descriptor
+```
+
+## Possibly-unbound `__get__` method
+
+```py
+def _(flag: bool):
+    class MaybeDescriptor:
+        if flag:
+            def __get__(self, instance: object, owner: type | None = None) -> int:
+                return 1
+
+    class C:
+        descriptor: MaybeDescriptor = MaybeDescriptor()
+
+    # TODO: This should be `MaybeDescriptor | int`
+    reveal_type(C.descriptor)  # revealed: int
+```
+
+## Dunder methods
+
+Dunder methods are looked up on the meta type, but we still need to invoke the descriptor protocol:
 
 ```py
 class SomeCallable:
@@ -491,67 +338,7 @@ reveal_type(b_instance(1))  # revealed: str
 b_instance("bla")  # error: [invalid-argument-type]
 ```
 
-## Special descriptors
-
-### Built-in `property` descriptor
-
-The built-in `property` decorator creates a descriptor. The names for attribute reads/writes are
-determined by the return type of the `name` method and the parameter type of the setter,
-respectively.
-
-```py
-class C:
-    _name: str | None = None
-
-    @property
-    def name(self) -> str:
-        return self._name or "Unset"
-
-    @name.setter
-    def name(self, value: str | None) -> None:
-        self._value = value
-
-c = C()
-
-reveal_type(c._name)  # revealed: str | None
-reveal_type(c.name)  # revealed: str
-reveal_type(C.name)  # revealed: property
-
-c.name = "new"
-c.name = None
-
-# error: [invalid-assignment] "Invalid assignment to data descriptor attribute `name` on type `C` with custom `__set__` method"
-c.name = 42
-```
-
-### Built-in `classmethod` descriptor
-
-Similarly to `property`, `classmethod` decorator creates an implicit descriptor that binds the first
-argument to the class instead of the instance.
-
-```py
-class C:
-    def __init__(self, value: str) -> None:
-        self._name: str = value
-
-    @classmethod
-    def factory(cls, value: str) -> "C":
-        return cls(value)
-
-    @classmethod
-    def get_name(cls) -> str:
-        return cls.__name__
-
-c1 = C.factory("test")  # okay
-
-reveal_type(c1)  # revealed: C
-
-reveal_type(C.get_name())  # revealed: str
-
-reveal_type(C("42").get_name())  # revealed: str
-```
-
-### Functions as descriptors
+## Functions as descriptors
 
 Functions are descriptors because they implement a `__get__` method. This is crucial in making sure
 that method calls work as expected. See [this test suite](./call/methods.md) for more information.
@@ -577,7 +364,7 @@ reveal_type(wrapper_descriptor(f, None, type(f)))  # revealed: Literal[f]
 reveal_type(f.__get__.__hash__)  # revealed: <bound method `__hash__` of `MethodWrapperType`>
 
 # Attribute access on the wrapper-descriptor falls back to `WrapperDescriptorType`:
-reveal_type(wrapper_descriptor.__qualname__)  # revealed: str
+reveal_type(wrapper_descriptor.__qualname__)  # revealed: @Todo(@property)
 ```
 
 We can also bind the free function `f` to an instance of a class `C`:
@@ -601,202 +388,32 @@ Finally, we test some error cases for the call to the wrapper descriptor:
 
 ```py
 # Calling the wrapper descriptor without any arguments is an
-# error: [no-matching-overload] "No overload of wrapper descriptor `FunctionType.__get__` matches arguments"
+# error: [missing-argument] "No arguments provided for required parameters `self`, `instance`"
 wrapper_descriptor()
 
 # Calling it without the `instance` argument is an also an
-# error: [no-matching-overload] "No overload of wrapper descriptor `FunctionType.__get__` matches arguments"
+# error: [missing-argument] "No argument provided for required parameter `instance`"
 wrapper_descriptor(f)
 
 # Calling it without the `owner` argument if `instance` is not `None` is an
-# error: [no-matching-overload] "No overload of wrapper descriptor `FunctionType.__get__` matches arguments"
+# error: [missing-argument] "No argument provided for required parameter `owner`"
 wrapper_descriptor(f, None)
 
 # But calling it with an instance is fine (in this case, the `owner` argument is optional):
 wrapper_descriptor(f, C())
 
 # Calling it with something that is not a `FunctionType` as the first argument is an
-# error: [no-matching-overload] "No overload of wrapper descriptor `FunctionType.__get__` matches arguments"
+# error: [invalid-argument-type] "Object of type `Literal[1]` cannot be assigned to parameter 1 (`self`); expected type `FunctionType`"
 wrapper_descriptor(1, None, type(f))
 
 # Calling it with something that is not a `type` as the `owner` argument is an
-# error: [no-matching-overload] "No overload of wrapper descriptor `FunctionType.__get__` matches arguments"
+# error: [invalid-argument-type] "Object of type `Literal[f]` cannot be assigned to parameter 3 (`owner`); expected type `type`"
 wrapper_descriptor(f, None, f)
 
 # Calling it with too many positional arguments is an
-# error: [no-matching-overload] "No overload of wrapper descriptor `FunctionType.__get__` matches arguments"
+# error: [too-many-positional-arguments] "Too many positional arguments: expected 3, got 4"
 wrapper_descriptor(f, None, type(f), "one too many")
 ```
 
-## Error handling and edge cases
-
-### `__get__` is called with correct arguments
-
-This test makes sure that we call `__get__` with the right argument types for various scenarios:
-
-```py
-from __future__ import annotations
-
-class TailoredForClassObjectAccess:
-    def __get__(self, instance: None, owner: type[C]) -> int:
-        return 1
-
-class TailoredForInstanceAccess:
-    def __get__(self, instance: C, owner: type[C] | None = None) -> str:
-        return "a"
-
-class TailoredForMetaclassAccess:
-    def __get__(self, instance: type[C], owner: type[Meta]) -> bytes:
-        return b"a"
-
-class Meta(type):
-    metaclass_access: TailoredForMetaclassAccess = TailoredForMetaclassAccess()
-
-class C(metaclass=Meta):
-    class_object_access: TailoredForClassObjectAccess = TailoredForClassObjectAccess()
-    instance_access: TailoredForInstanceAccess = TailoredForInstanceAccess()
-
-reveal_type(C.class_object_access)  # revealed: int
-reveal_type(C().instance_access)  # revealed: str
-reveal_type(C.metaclass_access)  # revealed: bytes
-
-# TODO: These should emit a diagnostic
-reveal_type(C().class_object_access)  # revealed: TailoredForClassObjectAccess
-reveal_type(C.instance_access)  # revealed: TailoredForInstanceAccess
-```
-
-### Descriptors with incorrect `__get__` signature
-
-```py
-class Descriptor:
-    # `__get__` method with missing parameters:
-    def __get__(self) -> int:
-        return 1
-
-class C:
-    descriptor: Descriptor = Descriptor()
-
-# TODO: This should be an error
-reveal_type(C.descriptor)  # revealed: Descriptor
-
-# TODO: This should be an error
-reveal_type(C().descriptor)  # revealed: Descriptor
-```
-
-### Undeclared descriptor arguments
-
-If a descriptor attribute is not declared, we union with `Unknown`, just like for regular
-attributes, since that attribute could be overwritten externally. Even a data descriptor with a
-`__set__` method can be overwritten when accessed through a class object.
-
-```py
-class Descriptor:
-    def __get__(self, instance: object, owner: type | None = None) -> int:
-        return 1
-
-    def __set__(self, instance: object, value: int) -> None:
-        pass
-
-class C:
-    descriptor = Descriptor()
-
-C.descriptor = "something else"
-
-# This could also be `Literal["something else"]` if we support narrowing of attribute types based on assignments
-reveal_type(C.descriptor)  # revealed: Unknown | int
-```
-
-### Possibly unbound descriptor attributes
-
-```py
-class DataDescriptor:
-    def __get__(self, instance: object, owner: type | None = None) -> int:
-        return 1
-
-    def __set__(self, instance: int, value) -> None:
-        pass
-
-class NonDataDescriptor:
-    def __get__(self, instance: object, owner: type | None = None) -> int:
-        return 1
-
-def _(flag: bool):
-    class PossiblyUnbound:
-        if flag:
-            non_data: NonDataDescriptor = NonDataDescriptor()
-            data: DataDescriptor = DataDescriptor()
-
-    # error: [possibly-unbound-attribute] "Attribute `non_data` on type `Literal[PossiblyUnbound]` is possibly unbound"
-    reveal_type(PossiblyUnbound.non_data)  # revealed: int
-
-    # error: [possibly-unbound-attribute] "Attribute `non_data` on type `PossiblyUnbound` is possibly unbound"
-    reveal_type(PossiblyUnbound().non_data)  # revealed: int
-
-    # error: [possibly-unbound-attribute] "Attribute `data` on type `Literal[PossiblyUnbound]` is possibly unbound"
-    reveal_type(PossiblyUnbound.data)  # revealed: int
-
-    # error: [possibly-unbound-attribute] "Attribute `data` on type `PossiblyUnbound` is possibly unbound"
-    reveal_type(PossiblyUnbound().data)  # revealed: int
-```
-
-### Possibly-unbound `__get__` method
-
-```py
-def _(flag: bool):
-    class MaybeDescriptor:
-        if flag:
-            def __get__(self, instance: object, owner: type | None = None) -> int:
-                return 1
-
-    class C:
-        descriptor: MaybeDescriptor = MaybeDescriptor()
-
-    reveal_type(C.descriptor)  # revealed: int | MaybeDescriptor
-
-    reveal_type(C().descriptor)  # revealed: int | MaybeDescriptor
-```
-
-### Descriptors with non-function `__get__` callables that are descriptors themselves
-
-The descriptor protocol is recursive, i.e. looking up `__get__` can involve triggering the
-descriptor protocol on the callable's `__call__` method:
-
-```py
-from __future__ import annotations
-
-class ReturnedCallable2:
-    def __call__(self, descriptor: Descriptor1, instance: None, owner: type[C]) -> int:
-        return 1
-
-class ReturnedCallable1:
-    def __call__(self, descriptor: Descriptor2, instance: Callable1, owner: type[Callable1]) -> ReturnedCallable2:
-        return ReturnedCallable2()
-
-class Callable3:
-    def __call__(self, descriptor: Descriptor3, instance: Callable2, owner: type[Callable2]) -> ReturnedCallable1:
-        return ReturnedCallable1()
-
-class Descriptor3:
-    __get__: Callable3 = Callable3()
-
-class Callable2:
-    __call__: Descriptor3 = Descriptor3()
-
-class Descriptor2:
-    __get__: Callable2 = Callable2()
-
-class Callable1:
-    __call__: Descriptor2 = Descriptor2()
-
-class Descriptor1:
-    __get__: Callable1 = Callable1()
-
-class C:
-    d: Descriptor1 = Descriptor1()
-
-reveal_type(C.d)  # revealed: int
-```
-
 [descriptors]: https://docs.python.org/3/howto/descriptor.html
-[precedence chain]: https://github.com/python/cpython/blob/3.13/Objects/typeobject.c#L5393-L5481
 [simple example]: https://docs.python.org/3/howto/descriptor.html#simple-example-a-descriptor-that-returns-a-constant