Add docs

[flake8-pytest-style] Do not emit diagnostics for empty for loops (PT012, PT031)
2025-01-16 20:29:45 -05:00 · 2025-01-17 00:12:53 +00:00
3784 changed files with 81568 additions and 212753 deletions
--- a/.cargo/config.toml
+++ b/.cargo/config.toml
@@ -8,7 +8,3 @@ benchmark = "bench -p ruff_benchmark --bench linter --bench formatter --"
 # See: https://github.com/astral-sh/ruff/issues/11503
 [target.'cfg(all(target_env="msvc", target_os = "windows"))']
 rustflags = ["-C", "target-feature=+crt-static"]
-
-[target.'wasm32-unknown-unknown']
-# See https://docs.rs/getrandom/latest/getrandom/#webassembly-support
-rustflags = ["--cfg", 'getrandom_backend="wasm_js"']
--- a/.config/nextest.toml
+++ b/.config/nextest.toml
@@ -6,10 +6,3 @@ failure-output = "immediate-final"
 fail-fast = false

 status-level = "skip"
-
-# Mark tests that take longer than 1s as slow.
-# Terminate after 60s as a stop-gap measure to terminate on deadlock.
-slow-timeout =  { period = "1s", terminate-after = 60 }
-
-# Show slow jobs in the final summary
-final-status-level = "slow"
--- a/.gitattributes
+++ b/.gitattributes
@@ -12,15 +12,7 @@ crates/ruff_python_parser/resources/invalid/re_lexing/line_continuation_windows_
 crates/ruff_python_parser/resources/invalid/re_lex_logical_token_windows_eol.py text eol=crlf
 crates/ruff_python_parser/resources/invalid/re_lex_logical_token_mac_eol.py text eol=cr

-crates/ruff_linter/resources/test/fixtures/ruff/RUF046_CR.py text eol=cr
-crates/ruff_linter/resources/test/fixtures/ruff/RUF046_LF.py text eol=lf
-
-crates/ruff_linter/resources/test/fixtures/pyupgrade/UP018_CR.py text eol=cr
-crates/ruff_linter/resources/test/fixtures/pyupgrade/UP018_LF.py text eol=lf
-
 crates/ruff_python_parser/resources/inline linguist-generated=true

-ruff.schema.json -diff linguist-generated=true text=auto eol=lf
-crates/ruff_python_ast/src/generated.rs -diff linguist-generated=true text=auto eol=lf
-crates/ruff_python_formatter/src/generated.rs -diff linguist-generated=true text=auto eol=lf
+ruff.schema.json linguist-generated=true text=auto eol=lf
 *.md.snap linguist-language=Markdown
--- a/.github/CODEOWNERS
+++ b/.github/CODEOWNERS
@@ -14,11 +14,10 @@
 # flake8-pyi
 /crates/ruff_linter/src/rules/flake8_pyi/ @AlexWaygood

-# Script for fuzzing the parser/ty etc.
+# Script for fuzzing the parser/red-knot etc.
 /python/py-fuzzer/ @AlexWaygood

-# ty
-/crates/ty* @carljm @MichaReiser @AlexWaygood @sharkdp @dcreager
-/crates/ruff_db/ @carljm @MichaReiser @AlexWaygood @sharkdp @dcreager
-/scripts/ty_benchmark/ @carljm @MichaReiser @AlexWaygood @sharkdp @dcreager
-/crates/ty_python_semantic @carljm @AlexWaygood @sharkdp @dcreager
+# red-knot
+/crates/red_knot* @carljm @MichaReiser @AlexWaygood @sharkdp
+/crates/ruff_db/ @carljm @MichaReiser @AlexWaygood @sharkdp
+/scripts/knot_benchmark/ @carljm @MichaReiser @AlexWaygood @sharkdp
--- a/.github/ISSUE_TEMPLATE/1_bug_report.yaml
+++ b/.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
--- a/.github/ISSUE_TEMPLATE/2_rule_request.yaml
+++ b/.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
--- a/.github/ISSUE_TEMPLATE/3_question.yaml
+++ b/.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
--- a/.github/ISSUE_TEMPLATE/config.yml
+++ b/.github/ISSUE_TEMPLATE/config.yml
@@ -1,11 +0,0 @@
-blank_issues_enabled: true
-contact_links:
-  - name: Report an issue with ty
-    url: https://github.com/astral-sh/ty/issues/new/choose
-    about: Please report issues for our type checker ty in the ty repository.
-  - 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.
--- a/.github/actionlint.yaml
+++ b/.github/actionlint.yaml
@@ -6,6 +6,4 @@ self-hosted-runner:
  labels:
    - depot-ubuntu-latest-8
    - depot-ubuntu-22.04-16
-    - depot-ubuntu-22.04-32
-    - github-windows-2025-x86_64-8
-    - github-windows-2025-x86_64-16
+    - windows-latest-xlarge
--- a/.github/renovate.json5
+++ b/.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",
@@ -106,7 +95,14 @@
      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: "",
--- a/.github/workflows/build-binaries.yml
+++ b/.github/workflows/build-binaries.yml
@@ -23,12 +23,10 @@ concurrency:
  group: ${{ github.workflow }}-${{ github.ref }}
  cancel-in-progress: true

-permissions: {}
-
 env:
  PACKAGE_NAME: ruff
  MODULE_NAME: ruff
-  PYTHON_VERSION: "3.13"
+  PYTHON_VERSION: "3.11"
  CARGO_INCREMENTAL: 0
  CARGO_NET_RETRY: 10
  CARGO_TERM_COLOR: always
@@ -39,17 +37,17 @@ jobs:
    if: ${{ !contains(github.event.pull_request.labels.*.name, 'no-build') }}
    runs-on: ubuntu-latest
    steps:
-      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+      - uses: actions/checkout@v4
        with:
          submodules: recursive
          persist-credentials: false
-      - uses: actions/setup-python@a26af69be951a213d495a4c3e4e4022e16d87065 # v5.6.0
+      - uses: actions/setup-python@v5
        with:
          python-version: ${{ env.PYTHON_VERSION }}
      - name: "Prep README.md"
        run: python scripts/transform_readme.py --target pypi
      - name: "Build sdist"
-        uses: PyO3/maturin-action@aef21716ff3dcae8a1c301d23ec3e4446972a6e3 # v1.49.1
+        uses: PyO3/maturin-action@v1
        with:
          command: sdist
          args: --out dist
@@ -59,7 +57,7 @@ jobs:
          "${MODULE_NAME}" --help
          python -m "${MODULE_NAME}" --help
      - name: "Upload sdist"
-        uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02 # v4.6.2
+        uses: actions/upload-artifact@v4
        with:
          name: wheels-sdist
          path: dist
@@ -68,23 +66,23 @@ jobs:
    if: ${{ !contains(github.event.pull_request.labels.*.name, 'no-build') }}
    runs-on: macos-14
    steps:
-      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+      - uses: actions/checkout@v4
        with:
          submodules: recursive
          persist-credentials: false
-      - uses: actions/setup-python@a26af69be951a213d495a4c3e4e4022e16d87065 # v5.6.0
+      - uses: actions/setup-python@v5
        with:
          python-version: ${{ env.PYTHON_VERSION }}
          architecture: x64
      - name: "Prep README.md"
        run: python scripts/transform_readme.py --target pypi
      - name: "Build wheels - x86_64"
-        uses: PyO3/maturin-action@aef21716ff3dcae8a1c301d23ec3e4446972a6e3 # v1.49.1
+        uses: PyO3/maturin-action@v1
        with:
          target: x86_64
          args: --release --locked --out dist
      - name: "Upload wheels"
-        uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02 # v4.6.2
+        uses: actions/upload-artifact@v4
        with:
          name: wheels-macos-x86_64
          path: dist
@@ -99,7 +97,7 @@ jobs:
          tar czvf $ARCHIVE_FILE $ARCHIVE_NAME
          shasum -a 256 $ARCHIVE_FILE > $ARCHIVE_FILE.sha256
      - name: "Upload binary"
-        uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02 # v4.6.2
+        uses: actions/upload-artifact@v4
        with:
          name: artifacts-macos-x86_64
          path: |
@@ -110,18 +108,18 @@ jobs:
    if: ${{ !contains(github.event.pull_request.labels.*.name, 'no-build') }}
    runs-on: macos-14
    steps:
-      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+      - uses: actions/checkout@v4
        with:
          submodules: recursive
          persist-credentials: false
-      - uses: actions/setup-python@a26af69be951a213d495a4c3e4e4022e16d87065 # v5.6.0
+      - uses: actions/setup-python@v5
        with:
          python-version: ${{ env.PYTHON_VERSION }}
          architecture: arm64
      - name: "Prep README.md"
        run: python scripts/transform_readme.py --target pypi
      - name: "Build wheels - aarch64"
-        uses: PyO3/maturin-action@aef21716ff3dcae8a1c301d23ec3e4446972a6e3 # v1.49.1
+        uses: PyO3/maturin-action@v1
        with:
          target: aarch64
          args: --release --locked --out dist
@@ -131,7 +129,7 @@ jobs:
          ruff --help
          python -m ruff --help
      - name: "Upload wheels"
-        uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02 # v4.6.2
+        uses: actions/upload-artifact@v4
        with:
          name: wheels-aarch64-apple-darwin
          path: dist
@@ -146,7 +144,7 @@ jobs:
          tar czvf $ARCHIVE_FILE $ARCHIVE_NAME
          shasum -a 256 $ARCHIVE_FILE > $ARCHIVE_FILE.sha256
      - name: "Upload binary"
-        uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02 # v4.6.2
+        uses: actions/upload-artifact@v4
        with:
          name: artifacts-aarch64-apple-darwin
          path: |
@@ -166,18 +164,18 @@ jobs:
          - target: aarch64-pc-windows-msvc
            arch: x64
    steps:
-      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+      - uses: actions/checkout@v4
        with:
          submodules: recursive
          persist-credentials: false
-      - uses: actions/setup-python@a26af69be951a213d495a4c3e4e4022e16d87065 # v5.6.0
+      - uses: actions/setup-python@v5
        with:
          python-version: ${{ env.PYTHON_VERSION }}
          architecture: ${{ matrix.platform.arch }}
      - name: "Prep README.md"
        run: python scripts/transform_readme.py --target pypi
      - name: "Build wheels"
-        uses: PyO3/maturin-action@aef21716ff3dcae8a1c301d23ec3e4446972a6e3 # v1.49.1
+        uses: PyO3/maturin-action@v1
        with:
          target: ${{ matrix.platform.target }}
          args: --release --locked --out dist
@@ -192,7 +190,7 @@ jobs:
          "${MODULE_NAME}" --help
          python -m "${MODULE_NAME}" --help
      - name: "Upload wheels"
-        uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02 # v4.6.2
+        uses: actions/upload-artifact@v4
        with:
          name: wheels-${{ matrix.platform.target }}
          path: dist
@@ -203,7 +201,7 @@ jobs:
          7z a $ARCHIVE_FILE ./target/${{ matrix.platform.target }}/release/ruff.exe
          sha256sum $ARCHIVE_FILE > $ARCHIVE_FILE.sha256
      - name: "Upload binary"
-        uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02 # v4.6.2
+        uses: actions/upload-artifact@v4
        with:
          name: artifacts-${{ matrix.platform.target }}
          path: |
@@ -219,18 +217,18 @@ jobs:
          - x86_64-unknown-linux-gnu
          - i686-unknown-linux-gnu
    steps:
-      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+      - uses: actions/checkout@v4
        with:
          submodules: recursive
          persist-credentials: false
-      - uses: actions/setup-python@a26af69be951a213d495a4c3e4e4022e16d87065 # v5.6.0
+      - uses: actions/setup-python@v5
        with:
          python-version: ${{ env.PYTHON_VERSION }}
          architecture: x64
      - name: "Prep README.md"
        run: python scripts/transform_readme.py --target pypi
      - name: "Build wheels"
-        uses: PyO3/maturin-action@aef21716ff3dcae8a1c301d23ec3e4446972a6e3 # v1.49.1
+        uses: PyO3/maturin-action@v1
        with:
          target: ${{ matrix.target }}
          manylinux: auto
@@ -242,7 +240,7 @@ jobs:
          "${MODULE_NAME}" --help
          python -m "${MODULE_NAME}" --help
      - name: "Upload wheels"
-        uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02 # v4.6.2
+        uses: actions/upload-artifact@v4
        with:
          name: wheels-${{ matrix.target }}
          path: dist
@@ -260,7 +258,7 @@ jobs:
          tar czvf $ARCHIVE_FILE $ARCHIVE_NAME
          shasum -a 256 $ARCHIVE_FILE > $ARCHIVE_FILE.sha256
      - name: "Upload binary"
-        uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02 # v4.6.2
+        uses: actions/upload-artifact@v4
        with:
          name: artifacts-${{ matrix.target }}
          path: |
@@ -294,24 +292,24 @@ jobs:
            arch: arm

    steps:
-      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+      - uses: actions/checkout@v4
        with:
          submodules: recursive
          persist-credentials: false
-      - uses: actions/setup-python@a26af69be951a213d495a4c3e4e4022e16d87065 # v5.6.0
+      - uses: actions/setup-python@v5
        with:
          python-version: ${{ env.PYTHON_VERSION }}
      - name: "Prep README.md"
        run: python scripts/transform_readme.py --target pypi
      - name: "Build wheels"
-        uses: PyO3/maturin-action@aef21716ff3dcae8a1c301d23ec3e4446972a6e3 # v1.49.1
+        uses: PyO3/maturin-action@v1
        with:
          target: ${{ matrix.platform.target }}
          manylinux: auto
          docker-options: ${{ matrix.platform.maturin_docker_options }}
          args: --release --locked --out dist
-      - uses: uraimo/run-on-arch-action@ac33288c3728ca72563c97b8b88dda5a65a84448 # v2
-        if: ${{ matrix.platform.arch != 'ppc64' && matrix.platform.arch != 'ppc64le'}}
+      - uses: uraimo/run-on-arch-action@v2
+        if: matrix.platform.arch != 'ppc64'
        name: Test wheel
        with:
          arch: ${{ matrix.platform.arch == 'arm' && 'armv6' || matrix.platform.arch }}
@@ -325,7 +323,7 @@ jobs:
            pip3 install ${{ env.PACKAGE_NAME }} --no-index --find-links dist/ --force-reinstall
            ruff --help
      - name: "Upload wheels"
-        uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02 # v4.6.2
+        uses: actions/upload-artifact@v4
        with:
          name: wheels-${{ matrix.platform.target }}
          path: dist
@@ -343,7 +341,7 @@ jobs:
          tar czvf $ARCHIVE_FILE $ARCHIVE_NAME
          shasum -a 256 $ARCHIVE_FILE > $ARCHIVE_FILE.sha256
      - name: "Upload binary"
-        uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02 # v4.6.2
+        uses: actions/upload-artifact@v4
        with:
          name: artifacts-${{ matrix.platform.target }}
          path: |
@@ -359,25 +357,25 @@ jobs:
          - x86_64-unknown-linux-musl
          - i686-unknown-linux-musl
    steps:
-      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+      - uses: actions/checkout@v4
        with:
          submodules: recursive
          persist-credentials: false
-      - uses: actions/setup-python@a26af69be951a213d495a4c3e4e4022e16d87065 # v5.6.0
+      - uses: actions/setup-python@v5
        with:
          python-version: ${{ env.PYTHON_VERSION }}
          architecture: x64
      - name: "Prep README.md"
        run: python scripts/transform_readme.py --target pypi
      - name: "Build wheels"
-        uses: PyO3/maturin-action@aef21716ff3dcae8a1c301d23ec3e4446972a6e3 # v1.49.1
+        uses: PyO3/maturin-action@v1
        with:
          target: ${{ matrix.target }}
          manylinux: musllinux_1_2
          args: --release --locked --out dist
      - name: "Test wheel"
        if: matrix.target == 'x86_64-unknown-linux-musl'
-        uses: addnab/docker-run-action@4f65fabd2431ebc8d299f8e5a018d79a769ae185 # v3
+        uses: addnab/docker-run-action@v3
        with:
          image: alpine:latest
          options: -v ${{ github.workspace }}:/io -w /io
@@ -387,7 +385,7 @@ jobs:
            .venv/bin/pip3 install ${{ env.PACKAGE_NAME }} --no-index --find-links dist/ --force-reinstall
            .venv/bin/${{ env.MODULE_NAME }} --help
      - name: "Upload wheels"
-        uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02 # v4.6.2
+        uses: actions/upload-artifact@v4
        with:
          name: wheels-${{ matrix.target }}
          path: dist
@@ -405,7 +403,7 @@ jobs:
          tar czvf $ARCHIVE_FILE $ARCHIVE_NAME
          shasum -a 256 $ARCHIVE_FILE > $ARCHIVE_FILE.sha256
      - name: "Upload binary"
-        uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02 # v4.6.2
+        uses: actions/upload-artifact@v4
        with:
          name: artifacts-${{ matrix.target }}
          path: |
@@ -425,23 +423,23 @@ jobs:
            arch: armv7

    steps:
-      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+      - uses: actions/checkout@v4
        with:
          submodules: recursive
          persist-credentials: false
-      - uses: actions/setup-python@a26af69be951a213d495a4c3e4e4022e16d87065 # v5.6.0
+      - uses: actions/setup-python@v5
        with:
          python-version: ${{ env.PYTHON_VERSION }}
      - name: "Prep README.md"
        run: python scripts/transform_readme.py --target pypi
      - name: "Build wheels"
-        uses: PyO3/maturin-action@aef21716ff3dcae8a1c301d23ec3e4446972a6e3 # v1.49.1
+        uses: PyO3/maturin-action@v1
        with:
          target: ${{ matrix.platform.target }}
          manylinux: musllinux_1_2
          args: --release --locked --out dist
          docker-options: ${{ matrix.platform.maturin_docker_options }}
-      - uses: uraimo/run-on-arch-action@ac33288c3728ca72563c97b8b88dda5a65a84448 # v2
+      - uses: uraimo/run-on-arch-action@v2
        name: Test wheel
        with:
          arch: ${{ matrix.platform.arch }}
@@ -454,7 +452,7 @@ jobs:
            .venv/bin/pip3 install ${{ env.PACKAGE_NAME }} --no-index --find-links dist/ --force-reinstall
            .venv/bin/${{ env.MODULE_NAME }} --help
      - name: "Upload wheels"
-        uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02 # v4.6.2
+        uses: actions/upload-artifact@v4
        with:
          name: wheels-${{ matrix.platform.target }}
          path: dist
@@ -472,7 +470,7 @@ jobs:
          tar czvf $ARCHIVE_FILE $ARCHIVE_NAME
          shasum -a 256 $ARCHIVE_FILE > $ARCHIVE_FILE.sha256
      - name: "Upload binary"
-        uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02 # v4.6.2
+        uses: actions/upload-artifact@v4
        with:
          name: artifacts-${{ matrix.platform.target }}
          path: |
--- a/.github/workflows/build-docker.yml
+++ b/.github/workflows/build-docker.yml
@@ -33,14 +33,14 @@ jobs:
          - linux/amd64
          - linux/arm64
    steps:
-      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+      - uses: actions/checkout@v4
        with:
          submodules: recursive
          persist-credentials: false

-      - uses: docker/setup-buildx-action@b5ca514318bd6ebac0fb2aedd5d36ec1b5c232a2 # v3
+      - uses: docker/setup-buildx-action@v3

-      - uses: docker/login-action@74a5d142397b4f367a81961eba4e8cd7edddf772 # v3
+      - uses: docker/login-action@v3
        with:
          registry: ghcr.io
          username: ${{ github.repository_owner }}
@@ -51,7 +51,7 @@ jobs:
        env:
          TAG: ${{ inputs.plan != '' && fromJson(inputs.plan).announcement_tag || 'dry-run' }}
        run: |
-          version=$(grep -m 1 "^version = " pyproject.toml | sed -e 's/version = "\(.*\)"/\1/g')
+          version=$(grep "version = " pyproject.toml | sed -e 's/version = "\(.*\)"/\1/g')
          if [ "${TAG}" != "${version}" ]; then
            echo "The input tag does not match the version from pyproject.toml:" >&2
            echo "${TAG}" >&2
@@ -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@14487ce63c7a62a4a324b0bfb37086795e31c6c1 # 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 # v4.6.2
+        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@d3f86a106a0bac45b974a628896c90dbdf5c8093 # v4.3.0
+        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@14487ce63c7a62a4a324b0bfb37086795e31c6c1 # 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@d3f86a106a0bac45b974a628896c90dbdf5c8093 # v4.3.0
+        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 }}
--- a/.github/workflows/ci.yaml
+++ b/.github/workflows/ci.yaml
@@ -1,7 +1,5 @@
 name: CI

-permissions: {}
-
 on:
  push:
    branches: [main]
@@ -18,7 +16,7 @@ env:
  CARGO_TERM_COLOR: always
  RUSTUP_MAX_RETRIES: 10
  PACKAGE_NAME: ruff
-  PYTHON_VERSION: "3.13"
+  PYTHON_VERSION: "3.12"

 jobs:
  determine_changes:
@@ -26,177 +24,82 @@ 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 ty changes.
-      ty: ${{ steps.check_ty.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 # v4.2.2
+      - uses: actions/checkout@v4
        with:
          fetch-depth: 0
          persist-credentials: false

-      - name: Determine merge base
-        id: merge_base
-        env:
-          BASE_REF: ${{ github.event.pull_request.base.ref || 'main' }}
-        run: |
-          sha=$(git merge-base HEAD "origin/${BASE_REF}")
-          echo "sha=${sha}" >> "$GITHUB_OUTPUT"
+      - uses: tj-actions/changed-files@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/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/ty*/**' \
-            ':!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/ty_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 ty code changed
-        id: check_ty
-        env:
-          MERGE_BASE: ${{ steps.merge_base.outputs.sha }}
-        run: |
-          if git diff --quiet "${MERGE_BASE}...HEAD" -- \
-            ':Cargo.toml' \
-            ':Cargo.lock' \
-            ':crates/ty*/**' \
-            ':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 # v4.2.2
+      - uses: actions/checkout@v4
        with:
          persist-credentials: false
      - name: "Install Rust toolchain"
@@ -210,50 +113,42 @@ jobs:
    if: ${{ needs.determine_changes.outputs.code == 'true' || github.ref == 'refs/heads/main' }}
    timeout-minutes: 20
    steps:
-      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+      - uses: actions/checkout@v4
        with:
          persist-credentials: false
-      - uses: Swatinem/rust-cache@9d47c6ad4b02e050fd481d890b2ea34778fd09d6 # v2.7.8
      - name: "Install Rust toolchain"
        run: |
          rustup component add clippy
          rustup target add wasm32-unknown-unknown
+      - uses: Swatinem/rust-cache@v2
      - name: "Clippy"
        run: cargo clippy --workspace --all-targets --all-features --locked -- -D warnings
      - name: "Clippy (wasm)"
-        run: cargo clippy -p ruff_wasm -p ty_wasm --target wasm32-unknown-unknown --all-features --locked -- -D warnings
+        run: cargo clippy -p ruff_wasm -p red_knot_wasm --target wasm32-unknown-unknown --all-features --locked -- -D warnings

  cargo-test-linux:
    name: "cargo test (linux)"
    runs-on: depot-ubuntu-22.04-16
    needs: determine_changes
-    if: ${{ !contains(github.event.pull_request.labels.*.name, 'no-test') && (needs.determine_changes.outputs.code == 'true' || github.ref == 'refs/heads/main') }}
+    if: ${{ needs.determine_changes.outputs.code == 'true' || github.ref == 'refs/heads/main' }}
    timeout-minutes: 20
    steps:
-      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+      - uses: actions/checkout@v4
        with:
          persist-credentials: false
-      - uses: Swatinem/rust-cache@9d47c6ad4b02e050fd481d890b2ea34778fd09d6 # v2.7.8
      - name: "Install Rust toolchain"
        run: rustup show
      - name: "Install mold"
-        uses: rui314/setup-mold@e16410e7f8d9e167b74ad5697a9089a35126eb50 # v1
+        uses: rui314/setup-mold@v1
      - name: "Install cargo nextest"
-        uses: taiki-e/install-action@86c23eed46c17b80677df6d8151545ce3e236c61 # v2
+        uses: taiki-e/install-action@v2
        with:
          tool: cargo-nextest
      - name: "Install cargo insta"
-        uses: taiki-e/install-action@86c23eed46c17b80677df6d8151545ce3e236c61 # v2
+        uses: taiki-e/install-action@v2
        with:
          tool: cargo-insta
-      - name: ty mdtests (GitHub annotations)
-        if: ${{ needs.determine_changes.outputs.ty == '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 ty_python_semantic --test mdtest || true
+      - uses: Swatinem/rust-cache@v2
      - name: "Run tests"
        shell: bash
        env:
@@ -268,42 +163,38 @@ jobs:
      # sync, not just public items. Eventually we should do this for all
      # crates; for now add crates here as they are warning-clean to prevent
      # regression.
-      - run: cargo doc --no-deps -p ty_python_semantic -p ty -p ty_test -p ruff_db --document-private-items
+      - run: cargo doc --no-deps -p red_knot_python_semantic -p red_knot -p red_knot_test -p ruff_db --document-private-items
        env:
          # Setting RUSTDOCFLAGS because `cargo doc --check` isn't yet implemented (https://github.com/rust-lang/cargo/issues/10025).
          RUSTDOCFLAGS: "-D warnings"
-      - uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02 # v4.6.2
+      - uses: actions/upload-artifact@v4
        with:
          name: ruff
          path: target/debug/ruff
-      - uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02 # v4.6.2
-        with:
-          name: ty
-          path: target/debug/ty

  cargo-test-linux-release:
    name: "cargo test (linux, release)"
    runs-on: depot-ubuntu-22.04-16
    needs: determine_changes
-    if: ${{ !contains(github.event.pull_request.labels.*.name, 'no-test') && (needs.determine_changes.outputs.code == 'true' || github.ref == 'refs/heads/main') }}
+    if: ${{ needs.determine_changes.outputs.code == 'true' || github.ref == 'refs/heads/main' }}
    timeout-minutes: 20
    steps:
-      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+      - uses: actions/checkout@v4
        with:
          persist-credentials: false
-      - uses: Swatinem/rust-cache@9d47c6ad4b02e050fd481d890b2ea34778fd09d6 # v2.7.8
      - name: "Install Rust toolchain"
        run: rustup show
      - name: "Install mold"
-        uses: rui314/setup-mold@e16410e7f8d9e167b74ad5697a9089a35126eb50 # v1
+        uses: rui314/setup-mold@v1
      - name: "Install cargo nextest"
-        uses: taiki-e/install-action@86c23eed46c17b80677df6d8151545ce3e236c61 # v2
+        uses: taiki-e/install-action@v2
        with:
          tool: cargo-nextest
      - name: "Install cargo insta"
-        uses: taiki-e/install-action@86c23eed46c17b80677df6d8151545ce3e236c61 # v2
+        uses: taiki-e/install-action@v2
        with:
          tool: cargo-insta
+      - uses: Swatinem/rust-cache@v2
      - name: "Run tests"
        shell: bash
        env:
@@ -312,25 +203,24 @@ jobs:

  cargo-test-windows:
    name: "cargo test (windows)"
-    runs-on: github-windows-2025-x86_64-16
+    runs-on: windows-latest-xlarge
    needs: determine_changes
-    if: ${{ !contains(github.event.pull_request.labels.*.name, 'no-test') && (needs.determine_changes.outputs.code == 'true' || github.ref == 'refs/heads/main') }}
+    if: ${{ needs.determine_changes.outputs.code == 'true' || github.ref == 'refs/heads/main' }}
    timeout-minutes: 20
    steps:
-      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+      - uses: actions/checkout@v4
        with:
          persist-credentials: false
-      - uses: Swatinem/rust-cache@9d47c6ad4b02e050fd481d890b2ea34778fd09d6 # v2.7.8
      - name: "Install Rust toolchain"
        run: rustup show
      - name: "Install cargo nextest"
-        uses: taiki-e/install-action@86c23eed46c17b80677df6d8151545ce3e236c61 # v2
+        uses: taiki-e/install-action@v2
        with:
          tool: cargo-nextest
+      - uses: Swatinem/rust-cache@v2
      - name: "Run tests"
        shell: bash
        env:
-          NEXTEST_PROFILE: "ci"
          # Workaround for <https://github.com/nextest-rs/nextest/issues/1493>.
          RUSTUP_WINDOWS_PATH_ADD_BIN: 1
        run: |
@@ -341,30 +231,30 @@ jobs:
    name: "cargo test (wasm)"
    runs-on: ubuntu-latest
    needs: determine_changes
-    if: ${{ !contains(github.event.pull_request.labels.*.name, 'no-test') && (needs.determine_changes.outputs.code == 'true' || github.ref == 'refs/heads/main') }}
+    if: ${{ needs.determine_changes.outputs.code == 'true' || github.ref == 'refs/heads/main' }}
    timeout-minutes: 10
    steps:
-      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+      - uses: actions/checkout@v4
        with:
          persist-credentials: false
-      - uses: Swatinem/rust-cache@9d47c6ad4b02e050fd481d890b2ea34778fd09d6 # v2.7.8
      - name: "Install Rust toolchain"
        run: rustup target add wasm32-unknown-unknown
-      - uses: actions/setup-node@49933ea5288caeca8642d1e84afbd3f7d6820020 # v4.4.0
+      - 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
+      - uses: Swatinem/rust-cache@v2
      - name: "Test ruff_wasm"
        run: |
          cd crates/ruff_wasm
          wasm-pack test --node
-      - name: "Test ty_wasm"
+      - name: "Test red_knot_wasm"
        run: |
-          cd crates/ty_wasm
+          cd crates/red_knot_wasm
          wasm-pack test --node

  cargo-build-release:
@@ -373,47 +263,47 @@ jobs:
    if: ${{ github.ref == 'refs/heads/main' }}
    timeout-minutes: 20
    steps:
-      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+      - uses: actions/checkout@v4
        with:
          persist-credentials: false
-      - uses: Swatinem/rust-cache@9d47c6ad4b02e050fd481d890b2ea34778fd09d6 # v2.7.8
      - name: "Install Rust toolchain"
        run: rustup show
      - name: "Install mold"
-        uses: rui314/setup-mold@e16410e7f8d9e167b74ad5697a9089a35126eb50 # v1
+        uses: rui314/setup-mold@v1
+      - uses: Swatinem/rust-cache@v2
      - name: "Build"
        run: cargo build --release --locked

  cargo-build-msrv:
    name: "cargo build (msrv)"
-    runs-on: depot-ubuntu-latest-8
+    runs-on: ubuntu-latest
    needs: determine_changes
-    if: ${{ !contains(github.event.pull_request.labels.*.name, 'no-test') && (needs.determine_changes.outputs.code == 'true' || github.ref == 'refs/heads/main') }}
+    if: ${{ needs.determine_changes.outputs.code == 'true' || github.ref == 'refs/heads/main' }}
    timeout-minutes: 20
    steps:
-      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+      - 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 # v2.7.8
      - name: "Install Rust toolchain"
        env:
          MSRV: ${{ steps.msrv.outputs.value }}
        run: rustup default "${MSRV}"
      - name: "Install mold"
-        uses: rui314/setup-mold@e16410e7f8d9e167b74ad5697a9089a35126eb50 # v1
+        uses: rui314/setup-mold@v1
      - name: "Install cargo nextest"
-        uses: taiki-e/install-action@86c23eed46c17b80677df6d8151545ce3e236c61 # v2
+        uses: taiki-e/install-action@v2
        with:
          tool: cargo-nextest
      - name: "Install cargo insta"
-        uses: taiki-e/install-action@86c23eed46c17b80677df6d8151545ce3e236c61 # v2
+        uses: taiki-e/install-action@v2
        with:
          tool: cargo-insta
+      - uses: Swatinem/rust-cache@v2
      - name: "Run tests"
        shell: bash
        env:
@@ -428,16 +318,16 @@ 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 # v4.2.2
+      - uses: actions/checkout@v4
        with:
          persist-credentials: false
-      - uses: Swatinem/rust-cache@9d47c6ad4b02e050fd481d890b2ea34778fd09d6 # v2.7.8
-        with:
-          workspaces: "fuzz -> target"
      - name: "Install Rust toolchain"
        run: rustup show
+      - uses: Swatinem/rust-cache@v2
+        with:
+          workspaces: "fuzz -> target"
      - name: "Install cargo-binstall"
-        uses: cargo-bins/cargo-binstall@63aaa5c1932cebabc34eceda9d92a70215dcead6 # v1.12.3
+        uses: cargo-bins/cargo-binstall@main
        with:
          tool: cargo-fuzz@0.11.2
      - name: "Install cargo-fuzz"
@@ -451,16 +341,16 @@ jobs:
    needs:
      - cargo-test-linux
      - determine_changes
-    if: ${{ !contains(github.event.pull_request.labels.*.name, 'no-test') && needs.determine_changes.outputs.parser == 'true' }}
+    if: ${{ needs.determine_changes.outputs.parser == 'true' }}
    timeout-minutes: 20
    env:
      FORCE_COLOR: 1
    steps:
-      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+      - uses: actions/checkout@v4
        with:
          persist-credentials: false
-      - uses: astral-sh/setup-uv@d4b2f3b6ecc6e67c4457f6d3e41ec42d3d0fcb86 # v5.4.2
-      - uses: actions/download-artifact@d3f86a106a0bac45b974a628896c90dbdf5c8093 # v4.3.0
+      - uses: astral-sh/setup-uv@v5
+      - uses: actions/download-artifact@v4
        name: Download Ruff binary to test
        id: download-cached-binary
        with:
@@ -487,21 +377,15 @@ jobs:
    name: "test scripts"
    runs-on: ubuntu-latest
    needs: determine_changes
-    if: ${{ !contains(github.event.pull_request.labels.*.name, 'no-test') && (needs.determine_changes.outputs.code == 'true' || github.ref == 'refs/heads/main') }}
+    if: ${{ needs.determine_changes.outputs.code == 'true' || github.ref == 'refs/heads/main' }}
    timeout-minutes: 5
    steps:
-      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+      - uses: actions/checkout@v4
        with:
          persist-credentials: false
-      - uses: Swatinem/rust-cache@9d47c6ad4b02e050fd481d890b2ea34778fd09d6 # v2.7.8
      - name: "Install Rust toolchain"
        run: rustup component add rustfmt
-      # Run all code generation scripts, and verify that the current output is
-      # already checked into git.
-      - run: python crates/ruff_python_ast/generate.py
-      - run: python crates/ruff_python_formatter/generate.py
-      - run: test -z "$(git status --porcelain)"
-      # Verify that adding a plugin or rule produces clean code.
+      - uses: Swatinem/rust-cache@v2
      - run: ./scripts/add_rule.py --name DoTheThing --prefix F --code 999 --linter pyflakes
      - run: cargo check
      - run: cargo fmt --all --check
@@ -519,24 +403,24 @@ jobs:
      - determine_changes
    # Only runs on pull requests, since that is the only we way we can find the base version for comparison.
    # Ecosystem check needs linter and/or formatter changes.
-    if: ${{ !contains(github.event.pull_request.labels.*.name, 'no-test') && github.event_name == 'pull_request' && needs.determine_changes.outputs.code == 'true' }}
+    if: ${{ github.event_name == 'pull_request' && needs.determine_changes.outputs.code == 'true' }}
    timeout-minutes: 20
    steps:
-      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+      - uses: actions/checkout@v4
        with:
          persist-credentials: false
-      - uses: actions/setup-python@a26af69be951a213d495a4c3e4e4022e16d87065 # v5.6.0
+      - uses: actions/setup-python@v5
        with:
          python-version: ${{ env.PYTHON_VERSION }}

-      - uses: actions/download-artifact@d3f86a106a0bac45b974a628896c90dbdf5c8093 # v4.3.0
+      - 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@v7
        name: Download baseline Ruff binary
        with:
          name: ruff
@@ -624,75 +508,28 @@ jobs:
        run: |
          echo ${{ github.event.number }} > pr-number

-      - uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02 # v4.6.2
+      - uses: actions/upload-artifact@v4
        name: Upload PR Number
        with:
          name: pr-number
          path: pr-number

-      - uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02 # v4.6.2
+      - uses: actions/upload-artifact@v4
        name: Upload Results
        with:
          name: ecosystem-result
          path: ecosystem-result

-  fuzz-ty:
-    name: "Fuzz for new ty panics"
-    runs-on: depot-ubuntu-22.04-16
-    needs:
-      - cargo-test-linux
-      - determine_changes
-    # Only runs on pull requests, since that is the only we way we can find the base version for comparison.
-    if: ${{ !contains(github.event.pull_request.labels.*.name, 'no-test') && github.event_name == 'pull_request' && needs.determine_changes.outputs.ty == 'true' }}
-    timeout-minutes: 20
-    steps:
-      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
-        with:
-          persist-credentials: false
-      - uses: actions/download-artifact@d3f86a106a0bac45b974a628896c90dbdf5c8093 # v4.3.0
-        name: Download new ty binary
-        id: ty-new
-        with:
-          name: ty
-          path: target/debug
-      - uses: dawidd6/action-download-artifact@20319c5641d495c8a52e688b7dc5fada6c3a9fbc # v8
-        name: Download baseline ty binary
-        with:
-          name: ty
-          branch: ${{ github.event.pull_request.base.ref }}
-          workflow: "ci.yaml"
-          check_artifacts: true
-      - uses: astral-sh/setup-uv@d4b2f3b6ecc6e67c4457f6d3e41ec42d3d0fcb86 # v5.4.2
-      - name: Fuzz
-        env:
-          FORCE_COLOR: 1
-          NEW_TY: ${{ steps.ty-new.outputs.download-path }}
-        run: |
-          # Make executable, since artifact download doesn't preserve this
-          chmod +x "${PWD}/ty" "${NEW_TY}/ty"
-
-          (
-            uvx \
-            --python="${PYTHON_VERSION}" \
-            --from=./python/py-fuzzer \
-            fuzz \
-            --test-executable="${NEW_TY}/ty" \
-            --baseline-executable="${PWD}/ty" \
-            --only-new-bugs \
-            --bin=ty \
-            0-500
-          )
-
  cargo-shear:
    name: "cargo shear"
    runs-on: ubuntu-latest
    needs: determine_changes
    if: ${{ needs.determine_changes.outputs.code == 'true' || github.ref == 'refs/heads/main' }}
    steps:
-      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+      - uses: actions/checkout@v4
        with:
          persist-credentials: false
-      - uses: cargo-bins/cargo-binstall@63aaa5c1932cebabc34eceda9d92a70215dcead6 # v1.12.3
+      - uses: cargo-bins/cargo-binstall@main
      - run: cargo binstall --no-confirm cargo-shear
      - run: cargo shear

@@ -700,20 +537,19 @@ jobs:
    name: "python package"
    runs-on: ubuntu-latest
    timeout-minutes: 20
-    if: ${{ !contains(github.event.pull_request.labels.*.name, 'no-test') }}
    steps:
-      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+      - uses: actions/checkout@v4
        with:
          persist-credentials: false
-      - uses: actions/setup-python@a26af69be951a213d495a4c3e4e4022e16d87065 # v5.6.0
+      - uses: actions/setup-python@v5
        with:
          python-version: ${{ env.PYTHON_VERSION }}
          architecture: x64
-      - uses: Swatinem/rust-cache@9d47c6ad4b02e050fd481d890b2ea34778fd09d6 # v2.7.8
+      - uses: Swatinem/rust-cache@v2
      - name: "Prep README.md"
        run: python scripts/transform_readme.py --target pypi
      - name: "Build wheels"
-        uses: PyO3/maturin-action@aef21716ff3dcae8a1c301d23ec3e4446972a6e3 # v1.49.1
+        uses: PyO3/maturin-action@v1
        with:
          args: --out dist
      - name: "Test wheel"
@@ -726,15 +562,22 @@ 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 # v4.2.2
+      - uses: actions/checkout@v4
        with:
          persist-credentials: false
-      - uses: astral-sh/setup-uv@d4b2f3b6ecc6e67c4457f6d3e41ec42d3d0fcb86 # v5.4.2
+      - uses: actions/setup-python@v5
+        with:
+          python-version: ${{ env.PYTHON_VERSION }}
+      - name: "Install Rust toolchain"
+        run: rustup show
+      - uses: Swatinem/rust-cache@v2
+      - name: "Install pre-commit"
+        run: pip install pre-commit
      - name: "Cache pre-commit"
-        uses: actions/cache@5a3ec84eff668545956fd18022155c47e93e2684 # v4.2.3
+        uses: actions/cache@v4
        with:
          path: ~/.cache/pre-commit
          key: pre-commit-${{ hashFiles('.pre-commit-config.yaml') }}
@@ -743,7 +586,7 @@ 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"
@@ -756,22 +599,22 @@ jobs:
    env:
      MKDOCS_INSIDERS_SSH_KEY_EXISTS: ${{ secrets.MKDOCS_INSIDERS_SSH_KEY != '' }}
    steps:
-      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+      - uses: actions/checkout@v4
        with:
          persist-credentials: false
-      - uses: actions/setup-python@a26af69be951a213d495a4c3e4e4022e16d87065 # v5.6.0
+      - uses: actions/setup-python@v5
        with:
          python-version: "3.13"
-      - uses: Swatinem/rust-cache@9d47c6ad4b02e050fd481d890b2ea34778fd09d6 # v2.7.8
      - 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@d4b2f3b6ecc6e67c4457f6d3e41ec42d3d0fcb86 # v5.4.2
+        uses: astral-sh/setup-uv@v5
+      - uses: Swatinem/rust-cache@v2
      - name: "Install Insiders dependencies"
        if: ${{ env.MKDOCS_INSIDERS_SSH_KEY_EXISTS == 'true' }}
        run: uv pip install -r docs/requirements-insiders.txt --system
@@ -795,15 +638,16 @@ jobs:
    name: "formatter instabilities and black similarity"
    runs-on: ubuntu-latest
    needs: determine_changes
-    if: ${{ !contains(github.event.pull_request.labels.*.name, 'no-test') && (needs.determine_changes.outputs.formatter == 'true' || github.ref == 'refs/heads/main') }}
+    if: needs.determine_changes.outputs.formatter == 'true' || github.ref == 'refs/heads/main'
    timeout-minutes: 10
    steps:
-      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+      - uses: actions/checkout@v4
        with:
          persist-credentials: false
-      - uses: Swatinem/rust-cache@9d47c6ad4b02e050fd481d890b2ea34778fd09d6 # v2.7.8
      - name: "Install Rust toolchain"
        run: rustup show
+      - name: "Cache rust"
+        uses: Swatinem/rust-cache@v2
      - name: "Run checks"
        run: scripts/formatter_ecosystem_checks.sh
      - name: "Github step summary"
@@ -818,24 +662,23 @@ jobs:
    needs:
      - cargo-test-linux
      - determine_changes
-    if: ${{ !contains(github.event.pull_request.labels.*.name, 'no-test') && (needs.determine_changes.outputs.code == 'true' || github.ref == 'refs/heads/main') }}
+    if: ${{ needs.determine_changes.outputs.code == 'true' || github.ref == 'refs/heads/main' }}
    steps:
-      - uses: extractions/setup-just@dd310ad5a97d8e7b41793f8ef055398d51ad4de6 # v2
+      - uses: extractions/setup-just@v2
        env:
          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}

-      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+      - uses: actions/checkout@v4
        name: "Download ruff-lsp source"
        with:
          persist-credentials: false
          repository: "astral-sh/ruff-lsp"

-      - uses: actions/setup-python@a26af69be951a213d495a4c3e4e4022e16d87065 # v5.6.0
+      - uses: actions/setup-python@v5
        with:
-          # installation fails on 3.13 and newer
-          python-version: "3.12"
+          python-version: ${{ env.PYTHON_VERSION }}

-      - uses: actions/download-artifact@d3f86a106a0bac45b974a628896c90dbdf5c8093 # v4.3.0
+      - uses: actions/download-artifact@v4
        name: Download development ruff binary
        id: ruff-target
        with:
@@ -858,65 +701,32 @@ 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 # v4.2.2
-        with:
-          persist-credentials: false
-      - name: "Install Rust toolchain"
-        run: rustup target add wasm32-unknown-unknown
-      - uses: Swatinem/rust-cache@9d47c6ad4b02e050fd481d890b2ea34778fd09d6 # v2.7.8
-      - uses: actions/setup-node@49933ea5288caeca8642d1e84afbd3f7d6820020 # v4.4.0
-        with:
-          node-version: 22
-          cache: "npm"
-          cache-dependency-path: playground/package-lock.json
-      - uses: jetli/wasm-bindgen-action@20b33e20595891ab1a0ed73145d8a21fc96e7c29 # v0.2.0
-      - name: "Install Node dependencies"
-        run: npm ci
-        working-directory: playground
-      - name: "Build playgrounds"
-        run: npm run dev:wasm
-        working-directory: playground
-      - name: "Run TypeScript checks"
-        run: npm run check
-        working-directory: playground
-      - name: "Check formatting"
-        run: npm run fmt:check
-        working-directory: playground
-
  benchmarks:
-    runs-on: ubuntu-24.04
+    runs-on: ubuntu-22.04
    needs: determine_changes
-    if: ${{ github.repository == 'astral-sh/ruff' && !contains(github.event.pull_request.labels.*.name, 'no-test') && (needs.determine_changes.outputs.code == 'true' || github.ref == 'refs/heads/main') }}
+    if: ${{ github.repository == 'astral-sh/ruff' && (needs.determine_changes.outputs.code == 'true' || github.ref == 'refs/heads/main') }}
    timeout-minutes: 20
    steps:
      - name: "Checkout Branch"
-        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+        uses: actions/checkout@v4
        with:
          persist-credentials: false

-      - uses: Swatinem/rust-cache@9d47c6ad4b02e050fd481d890b2ea34778fd09d6 # v2.7.8
-
      - name: "Install Rust toolchain"
        run: rustup show

      - name: "Install codspeed"
-        uses: taiki-e/install-action@86c23eed46c17b80677df6d8151545ce3e236c61 # v2
+        uses: taiki-e/install-action@v2
        with:
          tool: cargo-codspeed

+      - uses: Swatinem/rust-cache@v2
+
      - name: "Build benchmarks"
        run: cargo codspeed build --features codspeed -p ruff_benchmark

      - name: "Run benchmarks"
-        uses: CodSpeedHQ/action@0010eb0ca6e89b80c88e8edaaa07cfe5f3e6664d # v3.5.0
+        uses: CodSpeedHQ/action@v3
        with:
          run: cargo codspeed run
          token: ${{ secrets.CODSPEED_TOKEN }}
--- a/.github/workflows/daily_fuzz.yaml
+++ b/.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 # v4.2.2
+      - uses: actions/checkout@v4
        with:
          persist-credentials: false
-      - uses: astral-sh/setup-uv@d4b2f3b6ecc6e67c4457f6d3e41ec42d3d0fcb86 # v5.4.2
+      - uses: astral-sh/setup-uv@v5
      - name: "Install Rust toolchain"
        run: rustup show
      - name: "Install mold"
-        uses: rui314/setup-mold@e16410e7f8d9e167b74ad5697a9089a35126eb50 # v1
-      - uses: Swatinem/rust-cache@9d47c6ad4b02e050fd481d890b2ea34778fd09d6 # v2.7.8
+        uses: rui314/setup-mold@v1
+      - 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: |
--- a/.github/workflows/daily_property_tests.yaml
+++ b/.github/workflows/daily_property_tests.yaml
@@ -30,25 +30,24 @@ jobs:
    # Don't run the cron job on forks:
    if: ${{ github.repository == 'astral-sh/ruff' || github.event_name != 'schedule' }}
    steps:
-      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+      - uses: actions/checkout@v4
        with:
          persist-credentials: false
      - name: "Install Rust toolchain"
        run: rustup show
      - name: "Install mold"
-        uses: rui314/setup-mold@e16410e7f8d9e167b74ad5697a9089a35126eb50 # v1
-      - uses: Swatinem/rust-cache@9d47c6ad4b02e050fd481d890b2ea34778fd09d6 # v2.7.8
-      - name: Build ty
+        uses: rui314/setup-mold@v1
+      - 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.
-        run: cargo build --locked --release --package ty_python_semantic --tests
+        run: cargo build --locked --release --package red_knot_python_semantic --tests
      - name: Run property tests
        shell: bash
        run: |
          export QUICKCHECK_TESTS=100000
          for _ in {1..5}; do
-            cargo test --locked --release --package ty_python_semantic -- --ignored list::property_tests
-            cargo test --locked --release --package ty_python_semantic -- --ignored types::property_tests::stable
+            cargo test --locked --release --package red_knot_python_semantic -- --ignored types::property_tests::stable
          done

  create-issue-on-failure:
@@ -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: |
@@ -68,5 +67,5 @@ jobs:
              repo: "ruff",
              title: `Daily property test run failed on ${new Date().toDateString()}`,
              body: "Run listed here: https://github.com/${{ github.repository }}/actions/runs/${{ github.run_id }}",
-              labels: ["bug", "ty", "testing"],
+              labels: ["bug", "red-knot", "testing"],
            })
--- a/.github/workflows/mypy_primer.yaml
+++ b/.github/workflows/mypy_primer.yaml
@@ -1,96 +0,0 @@
-name: Run mypy_primer
-
-permissions: {}
-
-on:
-  pull_request:
-    paths:
-      - "crates/ty*/**"
-      - "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 }}-${{ github.event.pull_request.number || github.sha }}
-  cancel-in-progress: true
-
-env:
-  CARGO_INCREMENTAL: 0
-  CARGO_NET_RETRY: 10
-  CARGO_TERM_COLOR: always
-  RUSTUP_MAX_RETRIES: 10
-  RUST_BACKTRACE: 1
-
-jobs:
-  mypy_primer:
-    name: Run mypy_primer
-    runs-on: depot-ubuntu-22.04-32
-    timeout-minutes: 20
-    steps:
-      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
-        with:
-          path: ruff
-          fetch-depth: 0
-          persist-credentials: false
-
-      - name: Install the latest version of uv
-        uses: astral-sh/setup-uv@d4b2f3b6ecc6e67c4457f6d3e41ec42d3d0fcb86 # v5.4.2
-
-      - uses: Swatinem/rust-cache@9d47c6ad4b02e050fd481d890b2ea34778fd09d6 # v2.7.8
-        with:
-          workspaces: "ruff"
-
-      - name: Install Rust toolchain
-        run: rustup show
-
-      - name: Run mypy_primer
-        shell: bash
-        run: |
-          cd ruff
-
-          PRIMER_SELECTOR="$(paste -s -d'|' crates/ty_python_semantic/resources/primer/good.txt)"
-
-          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 ..
-
-          echo "Project selector: $PRIMER_SELECTOR"
-          # Allow the exit code to be 0 or 1, only fail for actual mypy_primer crashes/bugs
-          uvx \
-            --from="git+https://github.com/hauntsaninja/mypy_primer@4b15cf3b07db69db67bbfaebfffb2a8a28040933" \
-            mypy_primer \
-            --repo ruff \
-            --type-checker ty \
-            --old base_commit \
-            --new "$GITHUB_SHA" \
-            --project-selector "/($PRIMER_SELECTOR)\$" \
-            --output concise \
-            --debug > mypy_primer.diff || [ $? -eq 1 ]
-
-          # Output diff with ANSI color codes
-          cat mypy_primer.diff
-
-          # Remove ANSI color codes before uploading
-          sed -ie 's/\x1b\[[0-9;]*m//g' mypy_primer.diff
-
-          echo ${{ github.event.number }} > pr-number
-
-      - name: Upload diff
-        uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02 # v4.6.2
-        with:
-          name: mypy_primer_diff
-          path: mypy_primer.diff
-
-      - name: Upload pr-number
-        uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02 # v4.6.2
-        with:
-          name: pr-number
-          path: pr-number
--- a/.github/workflows/mypy_primer_comment.yaml
+++ b/.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
--- a/.github/workflows/notify-dependents.yml
+++ b/.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: ${{ secrets.RUFF_PRE_COMMIT_PAT }}
          script: |
--- a/.github/workflows/pr-comment.yaml
+++ b/.github/workflows/pr-comment.yaml
@@ -16,7 +16,7 @@ jobs:
    permissions:
      pull-requests: write
    steps:
-      - uses: dawidd6/action-download-artifact@20319c5641d495c8a52e688b7dc5fada6c3a9fbc # v8
+      - uses: dawidd6/action-download-artifact@v7
        name: Download pull request number
        with:
          name: pr-number
@@ -32,7 +32,7 @@ jobs:
            echo "pr-number=$(<pr-number)" >> "$GITHUB_OUTPUT"
          fi

-      - uses: dawidd6/action-download-artifact@20319c5641d495c8a52e688b7dc5fada6c3a9fbc # v8
+      - uses: dawidd6/action-download-artifact@v7
        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 }}
--- a/.github/workflows/publish-docs.yml
+++ b/.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 # v4.2.2
+      - uses: actions/checkout@v4
        with:
          ref: ${{ inputs.ref }}
          persist-credentials: true

-      - uses: actions/setup-python@a26af69be951a213d495a4c3e4e4022e16d87065 # v5.6.0
+      - 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 # v2.7.8
+      - uses: Swatinem/rust-cache@v2

      - name: "Install Insiders dependencies"
        if: ${{ env.MKDOCS_INSIDERS_SSH_KEY_EXISTS == 'true' }}
--- a/.github/workflows/publish-playground.yml
+++ b/.github/workflows/publish-playground.yml
@@ -24,31 +24,34 @@ jobs:
    env:
      CF_API_TOKEN_EXISTS: ${{ secrets.CF_API_TOKEN != '' }}
    steps:
-      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+      - uses: actions/checkout@v4
        with:
          persist-credentials: false
      - name: "Install Rust toolchain"
        run: rustup target add wasm32-unknown-unknown
-      - uses: actions/setup-node@49933ea5288caeca8642d1e84afbd3f7d6820020 # v4.4.0
+      - 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
+      - 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@v3.13.0
        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}
--- a/.github/workflows/publish-pypi.yml
+++ b/.github/workflows/publish-pypi.yml
@@ -22,8 +22,8 @@ jobs:
      id-token: write
    steps:
      - name: "Install uv"
-        uses: astral-sh/setup-uv@d4b2f3b6ecc6e67c4457f6d3e41ec42d3d0fcb86 # v5.4.2
-      - uses: actions/download-artifact@d3f86a106a0bac45b974a628896c90dbdf5c8093 # v4.3.0
+        uses: astral-sh/setup-uv@v5
+      - uses: actions/download-artifact@v4
        with:
          pattern: wheels-*
          path: wheels
--- a/.github/workflows/publish-ty-playground.yml
+++ b/.github/workflows/publish-ty-playground.yml
@@ -1,58 +0,0 @@
-# Publish the ty playground.
-name: "[ty Playground] Release"
-
-permissions: {}
-
-on:
-  push:
-    branches: [main]
-    paths:
-      - "crates/ty*/**"
-      - "crates/ruff_db/**"
-      - "crates/ruff_python_ast/**"
-      - "crates/ruff_python_parser/**"
-      - "playground/**"
-      - ".github/workflows/publish-ty-playground.yml"
-
-concurrency:
-  group: ${{ github.workflow }}-${{ github.ref_name }}
-  cancel-in-progress: true
-
-env:
-  CARGO_INCREMENTAL: 0
-  CARGO_NET_RETRY: 10
-  CARGO_TERM_COLOR: always
-  RUSTUP_MAX_RETRIES: 10
-
-jobs:
-  publish:
-    runs-on: ubuntu-latest
-    env:
-      CF_API_TOKEN_EXISTS: ${{ secrets.CF_API_TOKEN != '' }}
-    steps:
-      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
-        with:
-          persist-credentials: false
-      - name: "Install Rust toolchain"
-        run: rustup target add wasm32-unknown-unknown
-      - uses: actions/setup-node@49933ea5288caeca8642d1e84afbd3f7d6820020 # v4.4.0
-        with:
-          node-version: 22
-      - uses: jetli/wasm-bindgen-action@20b33e20595891ab1a0ed73145d8a21fc96e7c29 # v0.2.0
-      - name: "Install Node dependencies"
-        run: npm ci
-        working-directory: playground
-      - name: "Run TypeScript checks"
-        run: npm run check
-        working-directory: playground
-      - name: "Build ty playground"
-        run: npm run build --workspace ty-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/ty/dist --project-name=ty-playground --branch ${{ github.head_ref || 'main' }} --commit-hash ${GITHUB_SHA}
--- a/.github/workflows/publish-wasm.yml
+++ b/.github/workflows/publish-wasm.yml
@@ -29,15 +29,13 @@ jobs:
        target: [web, bundler, nodejs]
      fail-fast: false
    steps:
-      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+      - 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
-        with:
-          version: v0.13.1
-      - uses: jetli/wasm-bindgen-action@20b33e20595891ab1a0ed73145d8a21fc96e7c29 # v0.2.0
+      - uses: jetli/wasm-pack-action@v0.4.0
+      - uses: jetli/wasm-bindgen-action@v0.2.0
      - name: "Run wasm-pack build"
        run: wasm-pack build --target ${{ matrix.target }} crates/ruff_wasm
      - name: "Rename generated package"
@@ -45,7 +43,7 @@ jobs:
          jq '.name="@astral-sh/ruff-wasm-${{ 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@49933ea5288caeca8642d1e84afbd3f7d6820020 # v4.4.0
+      - uses: actions/setup-node@v4
        with:
          node-version: 20
          registry-url: "https://registry.npmjs.org"
--- a/.github/workflows/release.yml
+++ b/.github/workflows/release.yml
@@ -1,7 +1,6 @@
-# This file was autogenerated by dist: https://github.com/astral-sh/cargo-dist
+# This file was autogenerated by dist: https://opensource.axo.dev/cargo-dist/
 #
 # Copyright 2022-2024, axodotdev
-# Copyright 2025 Astral Software Inc.
 # SPDX-License-Identifier: MIT or Apache-2.0
 #
 # CI that:
@@ -40,7 +39,6 @@ permissions:
 # If there's a prerelease-style suffix to the version, then the release(s)
 # will be marked as a prerelease.
 on:
-  pull_request:
  workflow_dispatch:
    inputs:
      tag:
@@ -52,7 +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) || '' }}
@@ -61,17 +59,16 @@ jobs:
    env:
      GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
    steps:
-      - uses: actions/checkout@85e6279cec87321a52edac9c87bce653a07cf6c2
+      - uses: actions/checkout@v4
        with:
-          persist-credentials: false
          submodules: recursive
      - name: Install dist
        # we specify bash to get pipefail; it guards against the `curl` command
        # failing. otherwise `sh` won't catch that `curl` returned non-0
        shell: bash
-        run: "curl --proto '=https' --tlsv1.2 -LsSf https://github.com/astral-sh/cargo-dist/releases/download/v0.28.5-prerelease.1/cargo-dist-installer.sh | sh"
+        run: "curl --proto '=https' --tlsv1.2 -LsSf https://github.com/axodotdev/cargo-dist/releases/download/v0.25.2-prerelease.3/cargo-dist-installer.sh | sh"
      - name: Cache dist
-        uses: actions/upload-artifact@6027e3dd177782cd8ab9af838c04fd81a07f1d47
+        uses: actions/upload-artifact@v4
        with:
          name: cargo-dist-cache
          path: ~/.cargo/bin/dist
@@ -87,7 +84,7 @@ jobs:
          cat plan-dist-manifest.json
          echo "manifest=$(jq -c "." plan-dist-manifest.json)" >> "$GITHUB_OUTPUT"
      - name: "Upload dist-manifest.json"
-        uses: actions/upload-artifact@6027e3dd177782cd8ab9af838c04fd81a07f1d47
+        uses: actions/upload-artifact@v4
        with:
          name: artifacts-plan-dist-manifest
          path: plan-dist-manifest.json
@@ -119,24 +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@85e6279cec87321a52edac9c87bce653a07cf6c2
+      - uses: actions/checkout@v4
        with:
-          persist-credentials: false
          submodules: recursive
      - name: Install cached dist
-        uses: actions/download-artifact@d3f86a106a0bac45b974a628896c90dbdf5c8093
+        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@d3f86a106a0bac45b974a628896c90dbdf5c8093
+        uses: actions/download-artifact@v4
        with:
          pattern: artifacts-*
          path: target/distrib/
@@ -154,7 +150,7 @@ jobs:

          cp dist-manifest.json "$BUILD_MANIFEST_NAME"
      - name: "Upload artifacts"
-        uses: actions/upload-artifact@6027e3dd177782cd8ab9af838c04fd81a07f1d47
+        uses: actions/upload-artifact@v4
        with:
          name: artifacts-build-global
          path: |
@@ -171,23 +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: ${{ steps.host.outputs.manifest }}
    steps:
-      - uses: actions/checkout@85e6279cec87321a52edac9c87bce653a07cf6c2
+      - uses: actions/checkout@v4
        with:
-          persist-credentials: false
          submodules: recursive
      - name: Install cached dist
-        uses: actions/download-artifact@d3f86a106a0bac45b974a628896c90dbdf5c8093
+        uses: actions/download-artifact@v4
        with:
          name: cargo-dist-cache
          path: ~/.cargo/bin/
      - run: chmod +x ~/.cargo/bin/dist
      # Fetch artifacts from scratch-storage
      - name: Fetch artifacts
-        uses: actions/download-artifact@d3f86a106a0bac45b974a628896c90dbdf5c8093
+        uses: actions/download-artifact@v4
        with:
          pattern: artifacts-*
          path: target/distrib/
@@ -201,7 +196,7 @@ jobs:
          cat dist-manifest.json
          echo "manifest=$(jq -c "." dist-manifest.json)" >> "$GITHUB_OUTPUT"
      - name: "Upload dist-manifest.json"
-        uses: actions/upload-artifact@6027e3dd177782cd8ab9af838c04fd81a07f1d47
+        uses: actions/upload-artifact@v4
        with:
          # Overwrite the previous copy
          name: artifacts-dist-manifest
@@ -247,17 +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@85e6279cec87321a52edac9c87bce653a07cf6c2
+      - uses: actions/checkout@v4
        with:
-          persist-credentials: false
          submodules: recursive
      # Create a GitHub Release while uploading all files to it
      - name: "Download GitHub Artifacts"
-        uses: actions/download-artifact@d3f86a106a0bac45b974a628896c90dbdf5c8093
+        uses: actions/download-artifact@v4
        with:
          pattern: artifacts-*
          path: artifacts
--- a/.github/workflows/sync_typeshed.yaml
+++ b/.github/workflows/sync_typeshed.yaml
@@ -21,12 +21,12 @@ jobs:
      contents: write
      pull-requests: write
    steps:
-      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+      - uses: actions/checkout@v4
        name: Checkout Ruff
        with:
          path: ruff
          persist-credentials: true
-      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+      - uses: actions/checkout@v4
        name: Checkout typeshed
        with:
          repository: python/typeshed
@@ -39,13 +39,13 @@ jobs:
      - name: Sync typeshed
        id: sync
        run: |
-          rm -rf ruff/crates/ty_vendored/vendor/typeshed
-          mkdir ruff/crates/ty_vendored/vendor/typeshed
-          cp typeshed/README.md ruff/crates/ty_vendored/vendor/typeshed
-          cp typeshed/LICENSE ruff/crates/ty_vendored/vendor/typeshed
-          cp -r typeshed/stdlib ruff/crates/ty_vendored/vendor/typeshed/stdlib
-          rm -rf ruff/crates/ty_vendored/vendor/typeshed/stdlib/@tests
-          git -C typeshed rev-parse HEAD > ruff/crates/ty_vendored/vendor/typeshed/source_commit.txt
+          rm -rf ruff/crates/red_knot_vendored/vendor/typeshed
+          mkdir ruff/crates/red_knot_vendored/vendor/typeshed
+          cp typeshed/README.md ruff/crates/red_knot_vendored/vendor/typeshed
+          cp typeshed/LICENSE ruff/crates/red_knot_vendored/vendor/typeshed
+          cp -r typeshed/stdlib ruff/crates/red_knot_vendored/vendor/typeshed/stdlib
+          rm -rf ruff/crates/red_knot_vendored/vendor/typeshed/stdlib/@tests
+          git -C typeshed rev-parse HEAD > ruff/crates/red_knot_vendored/vendor/typeshed/source_commit.txt
      - name: Commit the changes
        id: commit
        if: ${{ steps.sync.outcome == 'success' }}
@@ -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: |
@@ -79,5 +79,5 @@ jobs:
              repo: "ruff",
              title: `Automated typeshed sync failed on ${new Date().toDateString()}`,
              body: "Run listed here: https://github.com/${{ github.repository }}/actions/runs/${{ github.run_id }}",
-              labels: ["bug", "ty"],
+              labels: ["bug", "red-knot"],
            })
--- a/.github/zizmor.yml
+++ b/.github/zizmor.yml
@@ -10,10 +10,3 @@ rules:
    ignore:
      - build-docker.yml
      - publish-playground.yml
-  excessive-permissions:
-    # it's hard to test what the impact of removing these ignores would be
-    # without actually running the release workflow...
-    ignore:
-      - build-docker.yml
-      - publish-playground.yml
-      - publish-docs.yml
--- a/.gitignore
+++ b/.gitignore
@@ -29,10 +29,6 @@ tracing.folded
 tracing-flamechart.svg
 tracing-flamegraph.svg

-# insta
-*.rs.pending-snap
-
-
 ###
 # Rust.gitignore
 ###
--- a/.ignore
+++ b/.ignore
@@ -1 +0,0 @@
-!/.github/
--- a/.pre-commit-config.yaml
+++ b/.pre-commit-config.yaml
@@ -3,9 +3,8 @@ fail_fast: false
 exclude: |
  (?x)^(
    .github/workflows/release.yml|
-    crates/ty_vendored/vendor/.*|
-    crates/ty_project/resources/.*|
-    crates/ruff_benchmark/resources/.*|
+    crates/red_knot_vendored/vendor/.*|
+    crates/red_knot_workspace/resources/.*|
    crates/ruff_linter/resources/.*|
    crates/ruff_linter/src/rules/.*/snapshots/.*|
    crates/ruff_notebook/resources/.*|
@@ -18,18 +17,13 @@ exclude: |
  )$

 repos:
-  - repo: https://github.com/pre-commit/pre-commit-hooks
-    rev: v5.0.0
-    hooks:
-      - id: check-merge-conflict
-
  - repo: https://github.com/abravalheri/validate-pyproject
-    rev: v0.24.1
+    rev: v0.23
    hooks:
      - id: validate-pyproject

  - repo: https://github.com/executablebooks/mdformat
-    rev: 0.7.22
+    rev: 0.7.21
    hooks:
      - id: mdformat
        additional_dependencies:
@@ -42,7 +36,7 @@ repos:
          )$

  - repo: https://github.com/igorshubovych/markdownlint-cli
-    rev: v0.44.0
+    rev: v0.43.0
    hooks:
      - id: markdownlint-fix
        exclude: |
@@ -62,10 +56,10 @@ repos:
            .*?invalid(_.+)*_syntax\.md
          )$
        additional_dependencies:
-          - black==25.1.0
+          - black==24.10.0

  - repo: https://github.com/crate-ci/typos
-    rev: v1.32.0
+    rev: v1.29.4
    hooks:
      - id: typos

@@ -79,7 +73,7 @@ repos:
        pass_filenames: false # This makes it a lot faster

  - repo: https://github.com/astral-sh/ruff-pre-commit
-    rev: v0.11.8
+    rev: v0.9.1
    hooks:
      - id: ruff-format
      - id: ruff
@@ -89,7 +83,7 @@ repos:

  # Prettier
  - repo: https://github.com/rbubley/mirrors-prettier
-    rev: v3.5.3
+    rev: v3.4.2
    hooks:
      - id: prettier
        types: [yaml]
@@ -97,19 +91,19 @@ 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: v1.6.0
+    rev: v1.0.1
    hooks:
      - id: zizmor

  - repo: https://github.com/python-jsonschema/check-jsonschema
-    rev: 0.33.0
+    rev: 0.31.0
    hooks:
      - id: check-github-workflows

  # `actionlint` hook, for verifying correct syntax in GitHub Actions workflows.
  # Some additional configuration for `actionlint` can be found in `.github/actionlint.yaml`.
  - repo: https://github.com/rhysd/actionlint
-    rev: v1.7.7
+    rev: v1.7.6
    hooks:
      - id: actionlint
        stages:
--- a/BREAKING_CHANGES.md
+++ b/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.
@@ -259,8 +209,8 @@ This change only affects those using Ruff under its default rule set. Users that

 ### Remove support for emoji identifiers ([#7212](https://github.com/astral-sh/ruff/pull/7212))

-Previously, Ruff supported non-standards-compliant emoji identifiers such as `📦 = 1`.
-We decided to remove this non-standard language extension. Ruff now reports syntax errors for invalid emoji identifiers in your code, the same as CPython.
+Previously, Ruff supported the non-standard compliant emoji identifiers e.g. `📦 = 1`.
+We decided to remove this non-standard language extension, and Ruff now reports syntax errors for emoji identifiers in your code, the same as CPython.

 ### Improved GitLab fingerprints ([#7203](https://github.com/astral-sh/ruff/pull/7203))

--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,650 +1,5 @@
 # Changelog

-## 0.11.8
-
-### Preview features
-
- \[`airflow`\] Apply auto fixes to cases where the names have changed in Airflow 3 (`AIR302`, `AIR311`) ([#17553](https://github.com/astral-sh/ruff/pull/17553), [#17570](https://github.com/astral-sh/ruff/pull/17570), [#17571](https://github.com/astral-sh/ruff/pull/17571))
- \[`airflow`\] Extend `AIR301` rule ([#17598](https://github.com/astral-sh/ruff/pull/17598))
- \[`airflow`\] Update existing `AIR302` rules with better suggestions ([#17542](https://github.com/astral-sh/ruff/pull/17542))
- \[`refurb`\] Mark fix as safe for `readlines-in-for` (`FURB129`) ([#17644](https://github.com/astral-sh/ruff/pull/17644))
- [syntax-errors] `nonlocal` declaration at module level ([#17559](https://github.com/astral-sh/ruff/pull/17559))
- [syntax-errors] Detect single starred expression assignment `x = *y` ([#17624](https://github.com/astral-sh/ruff/pull/17624))
-
-### Bug fixes
-
- \[`flake8-pyi`\] Ensure `Literal[None,] | Literal[None,]` is not autofixed to `None | None` (`PYI061`) ([#17659](https://github.com/astral-sh/ruff/pull/17659))
- \[`flake8-use-pathlib`\] Avoid suggesting `Path.iterdir()` for `os.listdir` with file descriptor (`PTH208`) ([#17715](https://github.com/astral-sh/ruff/pull/17715))
- \[`flake8-use-pathlib`\] Fix `PTH104` false positive when `rename` is passed a file descriptor ([#17712](https://github.com/astral-sh/ruff/pull/17712))
- \[`flake8-use-pathlib`\] Fix `PTH116` false positive when `stat` is passed a file descriptor ([#17709](https://github.com/astral-sh/ruff/pull/17709))
- \[`flake8-use-pathlib`\] Fix `PTH123` false positive when `open` is passed a file descriptor from a function call ([#17705](https://github.com/astral-sh/ruff/pull/17705))
- \[`pycodestyle`\] Fix duplicated diagnostic in `E712` ([#17651](https://github.com/astral-sh/ruff/pull/17651))
- \[`pylint`\] Detect `global` declarations in module scope (`PLE0118`) ([#17411](https://github.com/astral-sh/ruff/pull/17411))
- [syntax-errors] Make `async-comprehension-in-sync-comprehension` more specific ([#17460](https://github.com/astral-sh/ruff/pull/17460))
-
-### Configuration
-
- Add option to disable `typing_extensions` imports ([#17611](https://github.com/astral-sh/ruff/pull/17611))
-
-### Documentation
-
- Fix example syntax for the `lint.pydocstyle.ignore-var-parameters` option ([#17740](https://github.com/astral-sh/ruff/pull/17740))
- Add fix safety sections (`ASYNC116`, `FLY002`, `D200`, `RUF005`, `RUF017`, `RUF027`, `RUF028`, `RUF057`) ([#17497](https://github.com/astral-sh/ruff/pull/17497), [#17496](https://github.com/astral-sh/ruff/pull/17496), [#17502](https://github.com/astral-sh/ruff/pull/17502), [#17484](https://github.com/astral-sh/ruff/pull/17484), [#17480](https://github.com/astral-sh/ruff/pull/17480), [#17485](https://github.com/astral-sh/ruff/pull/17485), [#17722](https://github.com/astral-sh/ruff/pull/17722), [#17483](https://github.com/astral-sh/ruff/pull/17483))
-
-### Other changes
-
- Add Python 3.14 to configuration options ([#17647](https://github.com/astral-sh/ruff/pull/17647))
- Make syntax error for unparenthesized except tuples version specific to before 3.14 ([#17660](https://github.com/astral-sh/ruff/pull/17660))
-
-## 0.11.7
-
-### Preview features
-
- \[`airflow`\] Apply auto fixes to cases where the names have changed in Airflow 3 (`AIR301`) ([#17355](https://github.com/astral-sh/ruff/pull/17355))
- \[`perflint`\] Implement fix for `manual-dict-comprehension` (`PERF403`) ([#16719](https://github.com/astral-sh/ruff/pull/16719))
- [syntax-errors] Make duplicate parameter names a semantic error ([#17131](https://github.com/astral-sh/ruff/pull/17131))
-
-### Bug fixes
-
- \[`airflow`\] Fix typos in provider package names (`AIR302`, `AIR312`) ([#17574](https://github.com/astral-sh/ruff/pull/17574))
- \[`flake8-type-checking`\] Visit keyword arguments in checks involving `typing.cast`/`typing.NewType` arguments ([#17538](https://github.com/astral-sh/ruff/pull/17538))
- \[`pyupgrade`\] Preserve parenthesis when fixing native literals containing newlines (`UP018`) ([#17220](https://github.com/astral-sh/ruff/pull/17220))
- \[`refurb`\] Mark the `FURB161` fix unsafe except for integers and booleans ([#17240](https://github.com/astral-sh/ruff/pull/17240))
-
-### Rule changes
-
- \[`perflint`\] Allow list function calls to be replaced with a comprehension (`PERF401`) ([#17519](https://github.com/astral-sh/ruff/pull/17519))
- \[`pycodestyle`\] Auto-fix redundant boolean comparison (`E712`) ([#17090](https://github.com/astral-sh/ruff/pull/17090))
- \[`pylint`\] make fix unsafe if delete comments (`PLR1730`) ([#17459](https://github.com/astral-sh/ruff/pull/17459))
-
-### Documentation
-
- Add fix safety sections to docs for several rules ([#17410](https://github.com/astral-sh/ruff/pull/17410),[#17440](https://github.com/astral-sh/ruff/pull/17440),[#17441](https://github.com/astral-sh/ruff/pull/17441),[#17443](https://github.com/astral-sh/ruff/pull/17443),[#17444](https://github.com/astral-sh/ruff/pull/17444))
-
-## 0.11.6
-
-### Preview features
-
- Avoid adding whitespace to the end of a docstring after an escaped quote ([#17216](https://github.com/astral-sh/ruff/pull/17216))
- \[`airflow`\] Extract `AIR311` from `AIR301` rules (`AIR301`, `AIR311`) ([#17310](https://github.com/astral-sh/ruff/pull/17310), [#17422](https://github.com/astral-sh/ruff/pull/17422))
-
-### Bug fixes
-
- Raise syntax error when `\` is at end of file ([#17409](https://github.com/astral-sh/ruff/pull/17409))
-
-## 0.11.5
-
-### Preview features
-
- \[`airflow`\] Add missing `AIR302` attribute check ([#17115](https://github.com/astral-sh/ruff/pull/17115))
- \[`airflow`\] Expand module path check to individual symbols (`AIR302`) ([#17278](https://github.com/astral-sh/ruff/pull/17278))
- \[`airflow`\] Extract `AIR312` from `AIR302` rules (`AIR302`, `AIR312`) ([#17152](https://github.com/astral-sh/ruff/pull/17152))
- \[`airflow`\] Update oudated `AIR301`, `AIR302` rules ([#17123](https://github.com/astral-sh/ruff/pull/17123))
- [syntax-errors] Async comprehension in sync comprehension ([#17177](https://github.com/astral-sh/ruff/pull/17177))
- [syntax-errors] Check annotations in annotated assignments ([#17283](https://github.com/astral-sh/ruff/pull/17283))
- [syntax-errors] Extend annotation checks to `await` ([#17282](https://github.com/astral-sh/ruff/pull/17282))
-
-### Bug fixes
-
- \[`flake8-pie`\] Avoid false positive for multiple assignment with `auto()` (`PIE796`) ([#17274](https://github.com/astral-sh/ruff/pull/17274))
-
-### Rule changes
-
- \[`ruff`\] Fix `RUF100` to detect unused file-level `noqa` directives with specific codes (#17042) ([#17061](https://github.com/astral-sh/ruff/pull/17061))
- \[`flake8-pytest-style`\] Avoid false positive for legacy form of `pytest.raises` (`PT011`) ([#17231](https://github.com/astral-sh/ruff/pull/17231))
-
-### Documentation
-
- Fix formatting of "See Style Guide" link ([#17272](https://github.com/astral-sh/ruff/pull/17272))
-
-## 0.11.4
-
-### Preview features
-
- \[`ruff`\] Implement `invalid-rule-code` as `RUF102` ([#17138](https://github.com/astral-sh/ruff/pull/17138))
- [syntax-errors] Detect duplicate keys in `match` mapping patterns ([#17129](https://github.com/astral-sh/ruff/pull/17129))
- [syntax-errors] Detect duplicate attributes in `match` class patterns ([#17186](https://github.com/astral-sh/ruff/pull/17186))
- [syntax-errors] Detect invalid syntax in annotations ([#17101](https://github.com/astral-sh/ruff/pull/17101))
-
-### Bug fixes
-
- [syntax-errors] Fix multiple assignment error for class fields in `match` patterns ([#17184](https://github.com/astral-sh/ruff/pull/17184))
- Don't skip visiting non-tuple slice in `typing.Annotated` subscripts ([#17201](https://github.com/astral-sh/ruff/pull/17201))
-
-## 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
-
- Consider `__new__` methods as special function type for enforcing class method or static method rules ([#13305](https://github.com/astral-sh/ruff/pull/13305))
- \[`airflow`\] Improve the internal logic to differentiate deprecated symbols (`AIR303`) ([#16013](https://github.com/astral-sh/ruff/pull/16013))
- \[`refurb`\] Manual timezone monkeypatching (`FURB162`) ([#16113](https://github.com/astral-sh/ruff/pull/16113))
- \[`ruff`\] Implicit class variable in dataclass (`RUF045`) ([#14349](https://github.com/astral-sh/ruff/pull/14349))
- \[`ruff`\] Skip singleton starred expressions for `incorrectly-parenthesized-tuple-in-subscript` (`RUF031`) ([#16083](https://github.com/astral-sh/ruff/pull/16083))
- \[`refurb`\] Check for subclasses includes subscript expressions (`FURB189`) ([#16155](https://github.com/astral-sh/ruff/pull/16155))
-
-### Rule changes
-
- \[`flake8-debugger`\] Also flag `sys.breakpointhook` and `sys.__breakpointhook__` (`T100`) ([#16191](https://github.com/astral-sh/ruff/pull/16191))
- \[`pycodestyle`\] Exempt `site.addsitedir(...)` calls (`E402`) ([#16251](https://github.com/astral-sh/ruff/pull/16251))
-
-### Formatter
-
- Fix unstable formatting of trailing end-of-line comments of parenthesized attribute values ([#16187](https://github.com/astral-sh/ruff/pull/16187))
-
-### Server
-
- Fix handling of requests received after shutdown message ([#16262](https://github.com/astral-sh/ruff/pull/16262))
- Ignore `source.organizeImports.ruff` and `source.fixAll.ruff` code actions for a notebook cell ([#16154](https://github.com/astral-sh/ruff/pull/16154))
- Include document specific debug info for `ruff.printDebugInformation` ([#16215](https://github.com/astral-sh/ruff/pull/16215))
- Update server to return the debug info as string with `ruff.printDebugInformation` ([#16214](https://github.com/astral-sh/ruff/pull/16214))
-
-### CLI
-
- Warn on invalid `noqa` even when there are no diagnostics ([#16178](https://github.com/astral-sh/ruff/pull/16178))
- Better error messages while loading configuration `extend`s ([#15658](https://github.com/astral-sh/ruff/pull/15658))
-
-### 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
-
- Add FAQ entry for `source.*` code actions in Notebook ([#16212](https://github.com/astral-sh/ruff/pull/16212))
- Add `SECURITY.md` ([#16224](https://github.com/astral-sh/ruff/pull/16224))
-
-## 0.9.6
-
-### Preview features
-
- \[`airflow`\] Add `external_task.{ExternalTaskMarker, ExternalTaskSensor}` for `AIR302` ([#16014](https://github.com/astral-sh/ruff/pull/16014))
- \[`flake8-builtins`\] Make strict module name comparison optional (`A005`) ([#15951](https://github.com/astral-sh/ruff/pull/15951))
- \[`flake8-pyi`\] Extend fix to Python \<= 3.9 for `redundant-none-literal` (`PYI061`) ([#16044](https://github.com/astral-sh/ruff/pull/16044))
- \[`pylint`\] Also report when the object isn't a literal (`PLE1310`) ([#15985](https://github.com/astral-sh/ruff/pull/15985))
- \[`ruff`\] Implement `indented-form-feed` (`RUF054`) ([#16049](https://github.com/astral-sh/ruff/pull/16049))
- \[`ruff`\] Skip type definitions for `missing-f-string-syntax` (`RUF027`) ([#16054](https://github.com/astral-sh/ruff/pull/16054))
-
-### Rule changes
-
- \[`flake8-annotations`\] Correct syntax for `typing.Union` in suggested return type fixes for `ANN20x` rules ([#16025](https://github.com/astral-sh/ruff/pull/16025))
- \[`flake8-builtins`\] Match upstream module name comparison (`A005`) ([#16006](https://github.com/astral-sh/ruff/pull/16006))
- \[`flake8-comprehensions`\] Detect overshadowed `list`/`set`/`dict`, ignore variadics and named expressions (`C417`) ([#15955](https://github.com/astral-sh/ruff/pull/15955))
- \[`flake8-pie`\] Remove following comma correctly when the unpacked dictionary is empty (`PIE800`) ([#16008](https://github.com/astral-sh/ruff/pull/16008))
- \[`flake8-simplify`\] Only trigger `SIM401` on known dictionaries ([#15995](https://github.com/astral-sh/ruff/pull/15995))
- \[`pylint`\] Do not report calls when object type and argument type mismatch, remove custom escape handling logic (`PLE1310`) ([#15984](https://github.com/astral-sh/ruff/pull/15984))
- \[`pyupgrade`\] Comments within parenthesized value ranges should not affect applicability (`UP040`) ([#16027](https://github.com/astral-sh/ruff/pull/16027))
- \[`pyupgrade`\] Don't introduce invalid syntax when upgrading old-style type aliases with parenthesized multiline values (`UP040`) ([#16026](https://github.com/astral-sh/ruff/pull/16026))
- \[`pyupgrade`\] Ensure we do not rename two type parameters to the same name (`UP049`) ([#16038](https://github.com/astral-sh/ruff/pull/16038))
- \[`pyupgrade`\] \[`ruff`\] Don't apply renamings if the new name is shadowed in a scope of one of the references to the binding (`UP049`, `RUF052`) ([#16032](https://github.com/astral-sh/ruff/pull/16032))
- \[`ruff`\] Update `RUF009` to behave similar to `B008` and ignore attributes with immutable types ([#16048](https://github.com/astral-sh/ruff/pull/16048))
-
-### Server
-
- Root exclusions in the server to project root ([#16043](https://github.com/astral-sh/ruff/pull/16043))
-
-### Bug fixes
-
- \[`flake8-datetime`\] Ignore `.replace()` calls while looking for `.astimezone` ([#16050](https://github.com/astral-sh/ruff/pull/16050))
- \[`flake8-type-checking`\] Avoid `TC004` false positive where the runtime definition is provided by `__getattr__` ([#16052](https://github.com/astral-sh/ruff/pull/16052))
-
-### Documentation
-
- Improve `ruff-lsp` migration document ([#16072](https://github.com/astral-sh/ruff/pull/16072))
- Undeprecate `ruff.nativeServer` ([#16039](https://github.com/astral-sh/ruff/pull/16039))
-
-## 0.9.5
-
-### Preview features
-
- Recognize all symbols named `TYPE_CHECKING` for `in_type_checking_block` ([#15719](https://github.com/astral-sh/ruff/pull/15719))
- \[`flake8-comprehensions`\] Handle builtins at top of file correctly for `unnecessary-dict-comprehension-for-iterable` (`C420`) ([#15837](https://github.com/astral-sh/ruff/pull/15837))
- \[`flake8-logging`\] `.exception()` and `exc_info=` outside exception handlers (`LOG004`, `LOG014`) ([#15799](https://github.com/astral-sh/ruff/pull/15799))
- \[`flake8-pyi`\] Fix incorrect behaviour of `custom-typevar-return-type` preview-mode autofix if `typing` was already imported (`PYI019`) ([#15853](https://github.com/astral-sh/ruff/pull/15853))
- \[`flake8-pyi`\] Fix more complex cases (`PYI019`) ([#15821](https://github.com/astral-sh/ruff/pull/15821))
- \[`flake8-pyi`\] Make `PYI019` autofixable for `.py` files in preview mode as well as stubs ([#15889](https://github.com/astral-sh/ruff/pull/15889))
- \[`flake8-pyi`\] Remove type parameter correctly when it is the last (`PYI019`) ([#15854](https://github.com/astral-sh/ruff/pull/15854))
- \[`pylint`\] Fix missing parens in unsafe fix for `unnecessary-dunder-call` (`PLC2801`) ([#15762](https://github.com/astral-sh/ruff/pull/15762))
- \[`pyupgrade`\] Better messages and diagnostic range (`UP015`) ([#15872](https://github.com/astral-sh/ruff/pull/15872))
- \[`pyupgrade`\] Rename private type parameters in PEP 695 generics (`UP049`) ([#15862](https://github.com/astral-sh/ruff/pull/15862))
- \[`refurb`\] Also report non-name expressions (`FURB169`) ([#15905](https://github.com/astral-sh/ruff/pull/15905))
- \[`refurb`\] Mark fix as unsafe if there are comments (`FURB171`) ([#15832](https://github.com/astral-sh/ruff/pull/15832))
- \[`ruff`\] Classes with mixed type variable style (`RUF053`) ([#15841](https://github.com/astral-sh/ruff/pull/15841))
- \[`airflow`\] `BashOperator` has been moved to `airflow.providers.standard.operators.bash.BashOperator` (`AIR302`) ([#15922](https://github.com/astral-sh/ruff/pull/15922))
- \[`flake8-pyi`\] Add autofix for unused-private-type-var (`PYI018`) ([#15999](https://github.com/astral-sh/ruff/pull/15999))
- \[`flake8-pyi`\] Significantly improve accuracy of `PYI019` if preview mode is enabled ([#15888](https://github.com/astral-sh/ruff/pull/15888))
-
-### Rule changes
-
- Preserve triple quotes and prefixes for strings ([#15818](https://github.com/astral-sh/ruff/pull/15818))
- \[`flake8-comprehensions`\] Skip when `TypeError` present from too many (kw)args for `C410`,`C411`, and `C418` ([#15838](https://github.com/astral-sh/ruff/pull/15838))
- \[`flake8-pyi`\] Rename `PYI019` and improve its diagnostic message ([#15885](https://github.com/astral-sh/ruff/pull/15885))
- \[`pep8-naming`\] Ignore `@override` methods (`N803`) ([#15954](https://github.com/astral-sh/ruff/pull/15954))
- \[`pyupgrade`\] Reuse replacement logic from `UP046` and `UP047` to preserve more comments (`UP040`) ([#15840](https://github.com/astral-sh/ruff/pull/15840))
- \[`ruff`\] Analyze deferred annotations before enforcing `mutable-(data)class-default` and `function-call-in-dataclass-default-argument` (`RUF008`,`RUF009`,`RUF012`) ([#15921](https://github.com/astral-sh/ruff/pull/15921))
- \[`pycodestyle`\] Exempt `sys.path += ...` calls (`E402`) ([#15980](https://github.com/astral-sh/ruff/pull/15980))
-
-### Configuration
-
- Config error only when `flake8-import-conventions` alias conflicts with `isort.required-imports` bound name ([#15918](https://github.com/astral-sh/ruff/pull/15918))
- Workaround Even Better TOML crash related to `allOf` ([#15992](https://github.com/astral-sh/ruff/pull/15992))
-
-### Bug fixes
-
- \[`flake8-comprehensions`\] Unnecessary `list` comprehension (rewrite as a `set` comprehension) (`C403`) - Handle extraneous parentheses around list comprehension ([#15877](https://github.com/astral-sh/ruff/pull/15877))
- \[`flake8-comprehensions`\] Handle trailing comma in fixes for `unnecessary-generator-list/set` (`C400`,`C401`) ([#15929](https://github.com/astral-sh/ruff/pull/15929))
- \[`flake8-pyi`\] Fix several correctness issues with `custom-type-var-return-type` (`PYI019`) ([#15851](https://github.com/astral-sh/ruff/pull/15851))
- \[`pep8-naming`\] Consider any number of leading underscore for `N801` ([#15988](https://github.com/astral-sh/ruff/pull/15988))
- \[`pyflakes`\] Visit forward annotations in `TypeAliasType` as types (`F401`) ([#15829](https://github.com/astral-sh/ruff/pull/15829))
- \[`pylint`\] Correct min/max auto-fix and suggestion for (`PL1730`) ([#15930](https://github.com/astral-sh/ruff/pull/15930))
- \[`refurb`\] Handle unparenthesized tuples correctly (`FURB122`, `FURB142`) ([#15953](https://github.com/astral-sh/ruff/pull/15953))
- \[`refurb`\] Avoid `None | None` as well as better detection and fix (`FURB168`) ([#15779](https://github.com/astral-sh/ruff/pull/15779))
-
-### Documentation
-
- Add deprecation warning for `ruff-lsp` related settings ([#15850](https://github.com/astral-sh/ruff/pull/15850))
- Docs (`linter.md`): clarify that Python files are always searched for in subdirectories ([#15882](https://github.com/astral-sh/ruff/pull/15882))
- Fix a typo in `non_pep695_generic_class.rs` ([#15946](https://github.com/astral-sh/ruff/pull/15946))
- Improve Docs: Pylint subcategories' codes ([#15909](https://github.com/astral-sh/ruff/pull/15909))
- Remove non-existing `lint.extendIgnore` editor setting ([#15844](https://github.com/astral-sh/ruff/pull/15844))
- Update black deviations ([#15928](https://github.com/astral-sh/ruff/pull/15928))
- Mention `UP049` in `UP046` and `UP047`, add `See also` section to `UP040` ([#15956](https://github.com/astral-sh/ruff/pull/15956))
- Add instance variable examples to `RUF012` ([#15982](https://github.com/astral-sh/ruff/pull/15982))
- Explain precedence for `ignore` and `select` config ([#15883](https://github.com/astral-sh/ruff/pull/15883))
-
-## 0.9.4
-
-### Preview features
-
- \[`airflow`\] Extend airflow context parameter check for `BaseOperator.execute` (`AIR302`) ([#15713](https://github.com/astral-sh/ruff/pull/15713))
- \[`airflow`\] Update `AIR302` to check for deprecated context keys ([#15144](https://github.com/astral-sh/ruff/pull/15144))
- \[`flake8-bandit`\] Permit suspicious imports within stub files (`S4`) ([#15822](https://github.com/astral-sh/ruff/pull/15822))
- \[`pylint`\] Do not trigger `PLR6201` on empty collections ([#15732](https://github.com/astral-sh/ruff/pull/15732))
- \[`refurb`\] Do not emit diagnostic when loop variables are used outside loop body (`FURB122`) ([#15757](https://github.com/astral-sh/ruff/pull/15757))
- \[`ruff`\] Add support for more `re` patterns (`RUF055`) ([#15764](https://github.com/astral-sh/ruff/pull/15764))
- \[`ruff`\] Check for shadowed `map` before suggesting fix (`RUF058`) ([#15790](https://github.com/astral-sh/ruff/pull/15790))
- \[`ruff`\] Do not emit diagnostic when all arguments to `zip()` are variadic (`RUF058`) ([#15744](https://github.com/astral-sh/ruff/pull/15744))
- \[`ruff`\] Parenthesize fix when argument spans multiple lines for `unnecessary-round` (`RUF057`) ([#15703](https://github.com/astral-sh/ruff/pull/15703))
-
-### Rule changes
-
- Preserve quote style in generated code ([#15726](https://github.com/astral-sh/ruff/pull/15726), [#15778](https://github.com/astral-sh/ruff/pull/15778), [#15794](https://github.com/astral-sh/ruff/pull/15794))
- \[`flake8-bugbear`\] Exempt `NewType` calls where the original type is immutable (`B008`) ([#15765](https://github.com/astral-sh/ruff/pull/15765))
- \[`pylint`\] Honor banned top-level imports by `TID253` in `PLC0415`. ([#15628](https://github.com/astral-sh/ruff/pull/15628))
- \[`pyupgrade`\] Ignore `is_typeddict` and `TypedDict` for `deprecated-import` (`UP035`) ([#15800](https://github.com/astral-sh/ruff/pull/15800))
-
-### CLI
-
- Fix formatter warning message for `flake8-quotes` option ([#15788](https://github.com/astral-sh/ruff/pull/15788))
- Implement tab autocomplete for `ruff config` ([#15603](https://github.com/astral-sh/ruff/pull/15603))
-
-### Bug fixes
-
- \[`flake8-comprehensions`\] Do not emit `unnecessary-map` diagnostic when lambda has different arity (`C417`) ([#15802](https://github.com/astral-sh/ruff/pull/15802))
- \[`flake8-comprehensions`\] Parenthesize `sorted` when needed for `unnecessary-call-around-sorted` (`C413`) ([#15825](https://github.com/astral-sh/ruff/pull/15825))
- \[`pyupgrade`\] Handle end-of-line comments for `quoted-annotation` (`UP037`) ([#15824](https://github.com/astral-sh/ruff/pull/15824))
-
-### Documentation
-
- Add missing config docstrings ([#15803](https://github.com/astral-sh/ruff/pull/15803))
- Add references to `trio.run_process` and `anyio.run_process` ([#15761](https://github.com/astral-sh/ruff/pull/15761))
- Use `uv init --lib` in tutorial ([#15718](https://github.com/astral-sh/ruff/pull/15718))
-
-## 0.9.3
-
-### Preview features
-
- \[`airflow`\] Argument `fail_stop` in DAG has been renamed as `fail_fast` (`AIR302`) ([#15633](https://github.com/astral-sh/ruff/pull/15633))
- \[`airflow`\] Extend `AIR303` with more symbols ([#15611](https://github.com/astral-sh/ruff/pull/15611))
- \[`flake8-bandit`\] Report all references to suspicious functions (`S3`) ([#15541](https://github.com/astral-sh/ruff/pull/15541))
- \[`flake8-pytest-style`\] Do not emit diagnostics for empty `for` loops (`PT012`, `PT031`) ([#15542](https://github.com/astral-sh/ruff/pull/15542))
- \[`flake8-simplify`\] Avoid double negations (`SIM103`) ([#15562](https://github.com/astral-sh/ruff/pull/15562))
- \[`pyflakes`\] Fix infinite loop with unused local import in `__init__.py` (`F401`) ([#15517](https://github.com/astral-sh/ruff/pull/15517))
- \[`pylint`\] Do not report methods with only one `EM101`-compatible `raise` (`PLR6301`) ([#15507](https://github.com/astral-sh/ruff/pull/15507))
- \[`pylint`\] Implement `redefined-slots-in-subclass` (`W0244`) ([#9640](https://github.com/astral-sh/ruff/pull/9640))
- \[`pyupgrade`\] Add rules to use PEP 695 generics in classes and functions (`UP046`, `UP047`) ([#15565](https://github.com/astral-sh/ruff/pull/15565), [#15659](https://github.com/astral-sh/ruff/pull/15659))
- \[`refurb`\] Implement `for-loop-writes` (`FURB122`) ([#10630](https://github.com/astral-sh/ruff/pull/10630))
- \[`ruff`\] Implement `needless-else` clause (`RUF047`) ([#15051](https://github.com/astral-sh/ruff/pull/15051))
- \[`ruff`\] Implement `starmap-zip` (`RUF058`) ([#15483](https://github.com/astral-sh/ruff/pull/15483))
-
-### Rule changes
-
- \[`flake8-bugbear`\] Do not raise error if keyword argument is present and target-python version is less or equals than 3.9 (`B903`) ([#15549](https://github.com/astral-sh/ruff/pull/15549))
- \[`flake8-comprehensions`\] strip parentheses around generators in `unnecessary-generator-set` (`C401`) ([#15553](https://github.com/astral-sh/ruff/pull/15553))
- \[`flake8-pytest-style`\] Rewrite references to `.exception` (`PT027`) ([#15680](https://github.com/astral-sh/ruff/pull/15680))
- \[`flake8-simplify`\] Mark fixes as unsafe (`SIM201`, `SIM202`) ([#15626](https://github.com/astral-sh/ruff/pull/15626))
- \[`flake8-type-checking`\] Fix some safe fixes being labeled unsafe (`TC006`,`TC008`) ([#15638](https://github.com/astral-sh/ruff/pull/15638))
- \[`isort`\] Omit trailing whitespace in `unsorted-imports` (`I001`) ([#15518](https://github.com/astral-sh/ruff/pull/15518))
- \[`pydoclint`\] Allow ignoring one line docstrings for `DOC` rules ([#13302](https://github.com/astral-sh/ruff/pull/13302))
- \[`pyflakes`\] Apply redefinition fixes by source code order (`F811`) ([#15575](https://github.com/astral-sh/ruff/pull/15575))
- \[`pyflakes`\] Avoid removing too many imports in `redefined-while-unused` (`F811`) ([#15585](https://github.com/astral-sh/ruff/pull/15585))
- \[`pyflakes`\] Group redefinition fixes by source statement (`F811`) ([#15574](https://github.com/astral-sh/ruff/pull/15574))
- \[`pylint`\] Include name of base class in message for `redefined-slots-in-subclass` (`W0244`) ([#15559](https://github.com/astral-sh/ruff/pull/15559))
- \[`ruff`\] Update fix for `RUF055` to use `var == value` ([#15605](https://github.com/astral-sh/ruff/pull/15605))
-
-### Formatter
-
- Fix bracket spacing for single-element tuples in f-string expressions ([#15537](https://github.com/astral-sh/ruff/pull/15537))
- Fix unstable f-string formatting for expressions containing a trailing comma ([#15545](https://github.com/astral-sh/ruff/pull/15545))
-
-### Performance
-
- Avoid quadratic membership check in import fixes ([#15576](https://github.com/astral-sh/ruff/pull/15576))
-
-### Server
-
- Allow `unsafe-fixes` settings for code actions ([#15666](https://github.com/astral-sh/ruff/pull/15666))
-
-### Bug fixes
-
- \[`flake8-bandit`\] Add missing single-line/dotall regex flag (`S608`) ([#15654](https://github.com/astral-sh/ruff/pull/15654))
- \[`flake8-import-conventions`\] Fix infinite loop between `ICN001` and `I002` (`ICN001`) ([#15480](https://github.com/astral-sh/ruff/pull/15480))
- \[`flake8-simplify`\] Do not emit diagnostics for expressions inside string type annotations (`SIM222`, `SIM223`) ([#15405](https://github.com/astral-sh/ruff/pull/15405))
- \[`pyflakes`\] Treat arguments passed to the `default=` parameter of `TypeVar` as type expressions (`F821`) ([#15679](https://github.com/astral-sh/ruff/pull/15679))
- \[`pyupgrade`\] Avoid syntax error when the iterable is a non-parenthesized tuple (`UP028`) ([#15543](https://github.com/astral-sh/ruff/pull/15543))
- \[`ruff`\] Exempt `NewType` calls where the original type is immutable (`RUF009`) ([#15588](https://github.com/astral-sh/ruff/pull/15588))
- Preserve raw string prefix and escapes in all codegen fixes ([#15694](https://github.com/astral-sh/ruff/pull/15694))
-
-### Documentation
-
- Generate documentation redirects for lowercase rule codes ([#15564](https://github.com/astral-sh/ruff/pull/15564))
- `TRY300`: Add some extra notes on not catching exceptions you didn't expect ([#15036](https://github.com/astral-sh/ruff/pull/15036))
-
 ## 0.9.2

 ### Preview features
@@ -1566,11 +921,11 @@ 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:

--- a/CODE_OF_CONDUCT.md
+++ b/CODE_OF_CONDUCT.md
@@ -71,7 +71,8 @@ representative at an online or offline event.
 ## Enforcement

 Instances of abusive, harassing, or otherwise unacceptable behavior may be
-reported to the community leaders responsible for enforcement at <hey@astral.sh>.
+reported to the community leaders responsible for enforcement at
+<charlie.r.marsh@gmail.com>.
 All complaints will be reviewed and investigated promptly and fairly.

 All community leaders are obligated to respect the privacy and security of the
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -366,15 +366,6 @@ uvx --from ./python/ruff-ecosystem ruff-ecosystem format ruff "./target/debug/ru

 See the [ruff-ecosystem package](https://github.com/astral-sh/ruff/tree/main/python/ruff-ecosystem) for more details.

-## Upgrading Rust
-
-1. Change the `channel` in `./rust-toolchain.toml` to the new Rust version (`<latest>`)
-1. Change the `rust-version` in the `./Cargo.toml` to `<latest> - 2` (e.g. 1.84 if the latest is 1.86)
-1. Run `cargo clippy --fix --allow-dirty --allow-staged` to fix new clippy warnings
-1. Create and merge the PR
-1. Bump the Rust version in Ruff's conda forge recipe. See [this PR](https://github.com/conda-forge/ruff-feedstock/pull/266) for an example.
-1. Enjoy the new Rust version!
-
 ## Benchmarking and Profiling

 We have several ways of benchmarking and profiling Ruff:
@@ -535,7 +526,7 @@ cargo benchmark
 #### Benchmark-driven Development

 Ruff uses [Criterion.rs](https://bheisler.github.io/criterion.rs/book/) for benchmarks. You can use
-`--save-baseline=<name>` to store an initial baseline benchmark (e.g., on `main`) and then use
+`--save-baseline=<name>` to store an initial baseline benchmark (e.g. on `main`) and then use
 `--benchmark=<name>` to compare against that benchmark. Criterion will print a message telling you
 if the benchmark improved/regressed compared to that baseline.

@@ -687,9 +678,9 @@ utils with it:
 23 Newline 24
 ```

- `cargo dev print-cst <file>`: Print the CST of a Python file using
+- `cargo dev print-cst <file>`: Print the CST of a python file using
    [LibCST](https://github.com/Instagram/LibCST), which is used in addition to the RustPython parser
-    in Ruff. For example, for `if True: pass # comment`, everything, including the whitespace, is represented:
+    in Ruff. E.g. for `if True: pass # comment` everything including the whitespace is represented:

 ```text
 Module {
--- a/Cargo.lock
+++ b/Cargo.lock
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -4,7 +4,7 @@ resolver = "2"

 [workspace.package]
 edition = "2021"
-rust-version = "1.84"
+rust-version = "1.80"
 homepage = "https://docs.astral.sh/ruff"
 documentation = "https://docs.astral.sh/ruff"
 repository = "https://github.com/astral-sh/ruff"
@@ -35,14 +35,13 @@ ruff_python_trivia = { path = "crates/ruff_python_trivia" }
 ruff_server = { path = "crates/ruff_server" }
 ruff_source_file = { path = "crates/ruff_source_file" }
 ruff_text_size = { path = "crates/ruff_text_size" }
+red_knot_vendored = { path = "crates/red_knot_vendored" }
 ruff_workspace = { path = "crates/ruff_workspace" }

-ty_ide = { path = "crates/ty_ide" }
-ty_project = { path = "crates/ty_project", default-features = false }
-ty_python_semantic = { path = "crates/ty_python_semantic" }
-ty_server = { path = "crates/ty_server" }
-ty_test = { path = "crates/ty_test" }
-ty_vendored = { path = "crates/ty_vendored" }
+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_workspace = { path = "crates/red_knot_workspace", default-features = false }

 aho-corasick = { version = "1.1.3" }
 anstream = { version = "0.6.18" }
@@ -55,6 +54,7 @@ bitflags = { version = "2.5.0" }
 bstr = { version = "1.9.1" }
 cachedir = { version = "0.3.1" }
 camino = { version = "1.1.7" }
+chrono = { version = "0.4.35", default-features = false, features = ["clock"] }
 clap = { version = "4.5.3", features = ["derive"] }
 clap_complete_command = { version = "0.6.0" }
 clearscreen = { version = "4.0.0" }
@@ -63,7 +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" }
@@ -71,16 +71,14 @@ 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" }
 glob = { version = "0.3.1" }
 globset = { version = "0.4.14" }
 globwalk = { version = "0.9.1" }
 hashbrown = { version = "0.15.0", default-features = false, features = [
    "raw-entry",
-    "equivalent",
    "inline-more",
 ] }
 ignore = { version = "0.4.22" }
@@ -94,7 +92,6 @@ insta-cmd = { version = "0.6.0" }
 is-macro = { version = "0.3.5" }
 is-wsl = { version = "0.4.0" }
 itertools = { version = "0.14.0" }
-jiff = { version = "0.2.0" }
 js-sys = { version = "0.3.69" }
 jod-thread = { version = "0.1.2" }
 libc = { version = "0.2.153" }
@@ -108,7 +105,7 @@ matchit = { version = "0.8.1" }
 memchr = { version = "2.7.1" }
 mimalloc = { version = "0.1.39" }
 natord = { version = "1.0.9" }
-notify = { version = "8.0.0" }
+notify = { version = "7.0.0" }
 ordermap = { version = "0.5.0" }
 path-absolutize = { version = "3.1.1" }
 path-slash = { version = "0.2.1" }
@@ -119,12 +116,12 @@ proc-macro2 = { version = "1.0.79" }
 pyproject-toml = { version = "0.13.4" }
 quick-junit = { version = "0.5.0" }
 quote = { version = "1.0.23" }
-rand = { version = "0.9.0" }
+rand = { version = "0.8.5" }
 rayon = { version = "1.10.0" }
 regex = { version = "1.10.2" }
 rustc-hash = { version = "2.0.0" }
 # When updating salsa, make sure to also update the revision in `fuzz/Cargo.toml`
-salsa = { git = "https://github.com/salsa-rs/salsa.git", rev = "ef93d3830ffb8dc621fef1ba7b234ccef9dc3639" }
+salsa = { git = "https://github.com/salsa-rs/salsa.git", rev = "88a1d7774d78f048fbd77d40abca9ebd729fd1f0" }
 schemars = { version = "0.8.16" }
 seahash = { version = "4.1.0" }
 serde = { version = "1.0.197", features = ["derive"] }
@@ -137,15 +134,10 @@ serde_with = { version = "3.6.0", default-features = false, features = [
 shellexpand = { version = "3.0.0" }
 similar = { version = "2.4.0", features = ["inline"] }
 smallvec = { version = "1.13.2" }
-snapbox = { version = "0.6.0", features = [
-    "diff",
-    "term-svg",
-    "cmd",
-    "examples",
-] }
+snapbox = { version = "0.6.0", features = ["diff", "term-svg", "cmd", "examples"] }
 static_assertions = "1.1.0"
-strum = { version = "0.27.0", features = ["strum_macros"] }
-strum_macros = { version = "0.27.0" }
+strum = { version = "0.26.0", features = ["strum_macros"] }
+strum_macros = { version = "0.26.0" }
 syn = { version = "2.0.55" }
 tempfile = { version = "3.9.0" }
 test-case = { version = "3.3.1" }
@@ -155,7 +147,6 @@ 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",
@@ -168,6 +159,7 @@ unicode-ident = { version = "1.0.12" }
 unicode-width = { version = "0.2.0" }
 unicode_names2 = { version = "1.2.2" }
 unicode-normalization = { version = "0.1.23" }
+ureq = { version = "2.9.6" }
 url = { version = "2.5.0" }
 uuid = { version = "1.6.1", features = [
    "v4",
@@ -181,10 +173,6 @@ wasm-bindgen-test = { version = "0.3.42" }
 wild = { version = "2" }
 zip = { version = "0.6.6", default-features = false }

-[workspace.metadata.cargo-shear]
-ignored = ["getrandom"]
-
-
 [workspace.lints.rust]
 unsafe_code = "warn"
 unreachable_pub = "warn"
@@ -209,7 +197,6 @@ must_use_candidate = "allow"
 similar_names = "allow"
 single_match_else = "allow"
 too_many_lines = "allow"
-needless_continue = "allow"       # An explicit continue can be more readable, especially if the alternative is an empty block.
 # Without the hashes we run into a `rustfmt` bug in some snapshot tests, see #13250
 needless_raw_string_hashes = "allow"
 # Disallowed restriction lints
@@ -268,3 +255,60 @@ debug = 1
 # The profile that 'cargo dist' will build with.
 [profile.dist]
 inherits = "release"
+
+# Config for 'dist'
+[workspace.metadata.dist]
+# The preferred dist version to use in CI (Cargo.toml SemVer syntax)
+cargo-dist-version = "0.25.2-prerelease.3"
+# CI backends to support
+ci = "github"
+# The installers to generate for each app
+installers = ["shell", "powershell"]
+# The archive format to use for windows builds (defaults .zip)
+windows-archive = ".zip"
+# The archive format to use for non-windows builds (defaults .tar.xz)
+unix-archive = ".tar.gz"
+# Target platforms to build apps for (Rust target-triple syntax)
+targets = [
+    "aarch64-apple-darwin",
+    "aarch64-pc-windows-msvc",
+    "aarch64-unknown-linux-gnu",
+    "aarch64-unknown-linux-musl",
+    "arm-unknown-linux-musleabihf",
+    "armv7-unknown-linux-gnueabihf",
+    "armv7-unknown-linux-musleabihf",
+    "i686-pc-windows-msvc",
+    "i686-unknown-linux-gnu",
+    "i686-unknown-linux-musl",
+    "powerpc64-unknown-linux-gnu",
+    "powerpc64le-unknown-linux-gnu",
+    "s390x-unknown-linux-gnu",
+    "x86_64-apple-darwin",
+    "x86_64-pc-windows-msvc",
+    "x86_64-unknown-linux-gnu",
+    "x86_64-unknown-linux-musl",
+]
+# Whether to auto-include files like READMEs, LICENSEs, and CHANGELOGs (default true)
+auto-includes = false
+# Whether dist should create a Github Release or use an existing draft
+create-release = true
+# Which actions to run on pull requests
+pr-run-mode = "skip"
+# Whether CI should trigger releases with dispatches instead of tag pushes
+dispatch-releases = true
+# Which phase dist should use to create the GitHub release
+github-release = "announce"
+# Whether CI should include auto-generated code to build local artifacts
+build-local-artifacts = false
+# Local artifacts jobs to run in CI
+local-artifacts-jobs = ["./build-binaries", "./build-docker"]
+# Publish jobs to run in CI
+publish-jobs = ["./publish-pypi", "./publish-wasm"]
+# Post-announce jobs to run in CI
+post-announce-jobs = ["./notify-dependents", "./publish-docs", "./publish-playground"]
+# Custom permissions for GitHub Jobs
+github-custom-job-permissions = { "build-docker" = { packages = "write", contents = "read" }, "publish-wasm" = { contents = "read", id-token = "write", packages = "write" } }
+# Whether to install an updater program
+install-updater = false
+# Path that installers should place binaries in
+install-path = ["$XDG_BIN_HOME/", "$XDG_DATA_HOME/../bin", "~/.local/bin"]
--- a/README.md
+++ b/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/0.11.8/install.sh | sh
-powershell -c "irm https://astral.sh/ruff/0.11.8/install.ps1 | iex"
+curl -LsSf https://astral.sh/ruff/0.9.2/install.sh | sh
+powershell -c "irm https://astral.sh/ruff/0.9.2/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: v0.11.8
+  rev: v0.9.2
  hooks:
    # Run the linter.
    - id: ruff
@@ -452,7 +452,6 @@ Ruff is used by a number of major open-source projects and companies, including:
 - ING Bank ([popmon](https://github.com/ing-bank/popmon), [probatus](https://github.com/ing-bank/probatus))
 - [Ibis](https://github.com/ibis-project/ibis)
 - [ivy](https://github.com/unifyai/ivy)
- [JAX](https://github.com/jax-ml/jax)
 - [Jupyter](https://github.com/jupyter-server/jupyter_server)
 - [Kraken Tech](https://kraken.tech/)
 - [LangChain](https://github.com/hwchase17/langchain)
--- a/SECURITY.md
+++ b/SECURITY.md
@@ -1,15 +0,0 @@
-# Security policy
-
-## Reporting a vulnerability
-
-If you have found a possible vulnerability, please email `security at astral dot sh`.
-
-## Bug bounties
-
-While we sincerely appreciate and encourage reports of suspected security problems, please note that
-Astral does not currently run any bug bounty programs.
-
-## Vulnerability disclosures
-
-Critical vulnerabilities will be disclosed via GitHub's
-[security advisory](https://github.com/astral-sh/ruff/security) system.
--- a/_typos.toml
+++ b/_typos.toml
@@ -1,7 +1,7 @@
 [files]
 # https://github.com/crate-ci/typos/issues/868
 extend-exclude = [
-    "crates/ty_vendored/vendor/**/*",
+    "crates/red_knot_vendored/vendor/**/*",
    "**/resources/**/*",
    "**/snapshots/**/*",
 ]
@@ -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]
--- a/crates/red_knot/Cargo.toml
+++ b/crates/red_knot/Cargo.toml
@@ -1,51 +1,40 @@
 [package]
-name = "ty"
+name = "red_knot"
 version = "0.0.0"
 edition.workspace = true
 rust-version.workspace = true
 homepage.workspace = true
 documentation.workspace = true
-# Releases occur in this other repository!
-repository = "https://github.com/astral-sh/ty/"
+repository.workspace = true
 authors.workspace = true
 license.workspace = true

 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html

 [dependencies]
+red_knot_python_semantic = { workspace = true }
+red_knot_workspace = { workspace = true, features = ["zstd"] }
+red_knot_server = { workspace = true }
 ruff_db = { workspace = true, features = ["os", "cache"] }
-ruff_python_ast = { workspace = true }
-ty_python_semantic = { workspace = true }
-ty_project = { workspace = true, features = ["zstd"] }
-ty_server = { workspace = true }

 anyhow = { workspace = true }
-argfile = { workspace = true }
-clap = { workspace = true, features = ["wrap_help", "string"] }
-clap_complete_command = { workspace = true }
+chrono = { workspace = true }
+clap = { workspace = true, features = ["wrap_help"] }
 colored = { workspace = true }
 countme = { workspace = true, features = ["enable"] }
 crossbeam = { workspace = true }
 ctrlc = { version = "3.4.4" }
-jiff = { workspace = true }
 rayon = { workspace = true }
 salsa = { workspace = true }
 tracing = { workspace = true, features = ["release_max_level_debug"] }
 tracing-subscriber = { workspace = true, features = ["env-filter", "fmt"] }
 tracing-flame = { workspace = true }
 tracing-tree = { workspace = true }
-wild = { workspace = true }

 [dev-dependencies]
-ruff_db = { workspace = true, features = ["testing"] }
-ruff_python_trivia = { workspace = true }
-
-insta = { workspace = true, features = ["filters"] }
-insta-cmd = { workspace = true }
 filetime = { workspace = true }
-regex = { workspace = true }
 tempfile = { workspace = true }
-toml = { workspace = true }
+ruff_db = { workspace = true, features = ["testing"] }

 [lints]
 workspace = true
--- a/crates/red_knot/docs/tracing-flamegraph.png
+++ b/crates/red_knot/docs/tracing-flamegraph.png
--- a/crates/red_knot/docs/tracing.md
+++ b/crates/red_knot/docs/tracing.md
@@ -1,7 +1,6 @@
 # Tracing

-Traces are a useful tool to narrow down the location of a bug or, at least, to understand why the compiler is doing a
-particular thing.
+Traces are a useful tool to narrow down the location of a bug or, at least, to understand why the compiler is doing a particular thing.
 Note, tracing messages with severity `debug` or greater are user-facing. They should be phrased accordingly.
 Tracing spans are only shown when using `-vvv`.

@@ -10,28 +9,20 @@ Tracing spans are only shown when using `-vvv`.
 The CLI supports different verbosity levels.

 - default: Only show errors and warnings.
- `-v` activates `info!`: Show generally useful information such as paths of configuration files, detected platform,
-    etc., but it's not a lot of messages, it's something you'll activate in CI by default. cargo build e.g. shows you
-    which packages are fresh.
- `-vv` activates `debug!` and timestamps: This should be enough information to get to the bottom of bug reports. When
-    you're processing many packages or files, you'll get pages and pages of output, but each line is link to a specific
-    action or state change.
- `-vvv` activates `trace!` (only in debug builds) and shows tracing-spans: At this level, you're logging everything.
-    Most of this is wasted, it's really slow, we dump e.g. the entire resolution graph. Only useful to developers, and you
-    almost certainly want to use `TY_LOG` to filter it down to the area your investigating.
+- `-v` activates `info!`: Show generally useful information such as paths of configuration files, detected platform, etc., but it's not a lot of messages, it's something you'll activate in CI by default. cargo build e.g. shows you which packages are fresh.
+- `-vv` activates `debug!` and timestamps: This should be enough information to get to the bottom of bug reports. When you're processing many packages or files, you'll get pages and pages of output, but each line is link to a specific action or state change.
+- `-vvv` activates `trace!` (only in debug builds) and shows tracing-spans: At this level, you're logging everything. Most of this is wasted, it's really slow, we dump e.g. the entire resolution graph. Only useful to developers, and you almost certainly want to use `RED_KNOT_LOG` to filter it down to the area your investigating.

-## Better logging with `TY_LOG` and `TY_MAX_PARALLELISM`
+## Better logging with `RED_KNOT_LOG` and `RAYON_NUM_THREADS`

-By default, the CLI shows messages from the `ruff` and `ty` crates. Tracing messages from other crates are not shown.
-The `TY_LOG` environment variable allows you to customize which messages are shown by specifying one
-or
-more [filter directives](https://docs.rs/tracing-subscriber/latest/tracing_subscriber/filter/struct.EnvFilter.html#directives).
+By default, the CLI shows messages from the `ruff` and `red_knot` crates. Tracing messages from other crates are not shown.
+The `RED_KNOT_LOG` environment variable allows you to customize which messages are shown by specifying one
+or more [filter directives](https://docs.rs/tracing-subscriber/latest/tracing_subscriber/filter/struct.EnvFilter.html#directives).

-The `TY_MAX_PARALLELISM` environment variable, meanwhile, can be used to control the level of parallelism ty uses.
-By default, ty will attempt to parallelize its work so that multiple files are checked simultaneously,
-but this can result in a confused logging output where messages from different threads are intertwined and non
-determinism.
-To switch off parallelism entirely and have more readable logs, use `TY_MAX_PARALLELISM=1` (or `RAYON_NUM_THREADS=1`).
+The `RAYON_NUM_THREADS` environment variable, meanwhile, can be used to control the level of concurrency red-knot uses.
+By default, red-knot will attempt to parallelize its work so that multiple files are checked simultaneously,
+but this can result in a confused logging output where messages from different threads are intertwined.
+To switch off concurrency entirely and have more readable logs, use `RAYON_NUM_THREADS=1`.

 ### Examples

@@ -40,23 +31,23 @@ To switch off parallelism entirely and have more readable logs, use `TY_MAX_PARA
 Shows debug messages from all crates.

 ```bash
-TY_LOG=debug
+RED_KNOT_LOG=debug
 ```

 #### Show salsa query execution messages

-Show the salsa `execute: my_query` messages in addition to all ty messages.
+Show the salsa `execute: my_query` messages in addition to all red knot messages.

 ```bash
-TY_LOG=ruff=trace,ty=trace,salsa=info
+RED_KNOT_LOG=ruff=trace,red_knot=trace,salsa=info
 ```

 #### Show typing traces

-Only show traces for the `ty_python_semantic::types` module.
+Only show traces for the `red_knot_python_semantic::types` module.

 ```bash
-TY_LOG="ty_python_semantic::types"
+RED_KNOT_LOG="red_knot_python_semantic::types"
 ```

 Note: Ensure that you use `-vvv` to see tracing spans.
@@ -66,7 +57,7 @@ Note: Ensure that you use `-vvv` to see tracing spans.
 Shows all messages that are inside of a span for a specific file.

 ```bash
-TY_LOG=ty[{file=/home/micha/astral/test/x.py}]=trace
+RED_KNOT_LOG=red_knot[{file=/home/micha/astral/test/x.py}]=trace
 ```

 **Note**: Tracing still shows all spans because tracing can't know at the time of entering the span
@@ -88,24 +79,22 @@ query to return the failure as part of the query's result or use a Salsa accumul

 ## Tracing in tests

-You can use `ruff_db::testing::setup_logging` or `ruff_db::testing::setup_logging_with_filter` to set up logging in
-tests.
+You can use `ruff_db::testing::setup_logging` or `ruff_db::testing::setup_logging_with_filter` to set up logging in tests.

 ```rust
 use ruff_db::testing::setup_logging;

 #[test]
 fn test() {
-    let _logging = setup_logging();
+  let _logging = setup_logging();

-    tracing::info!("This message will be printed to stderr");
+  tracing::info!("This message will be printed to stderr");
 }
 ```

 Note: Most test runners capture stderr and only show its output when a test fails.

-Note also that `setup_logging` only sets up logging for the current thread because
-[`set_global_default`](https://docs.rs/tracing/latest/tracing/subscriber/fn.set_global_default.html) can only be
+Note also that `setup_logging` only sets up logging for the current thread because [`set_global_default`](https://docs.rs/tracing/latest/tracing/subscriber/fn.set_global_default.html) can only be
 called **once**.

 ## Release builds
@@ -114,11 +103,10 @@ called **once**.

 ## Profiling

-ty generates a folded stack trace to the current directory named `tracing.folded` when setting the environment variable
-`TY_LOG_PROFILE` to `1` or `true`.
+Red Knot generates a folded stack trace to the current directory named `tracing.folded` when setting the environment variable `RED_KNOT_LOG_PROFILE` to `1` or `true`.

 ```bash
-TY_LOG_PROFILE=1 ty -- --current-directory=../test -vvv
+RED_KNOT_LOG_PROFILE=1 red_knot -- --current-directory=../test -vvv
 ```

 You can convert the textual representation into a visual one using `inferno`.
--- a/crates/red_knot/src/logging.rs
+++ b/crates/red_knot/src/logging.rs
@@ -1,4 +1,4 @@
-//! Sets up logging for ty
+//! Sets up logging for Red Knot

 use anyhow::Context;
 use colored::Colorize;
@@ -42,14 +42,14 @@ impl Verbosity {

 #[derive(Debug, Copy, Clone, Eq, PartialEq, Ord, PartialOrd)]
 pub(crate) enum VerbosityLevel {
-    /// Default output level. Only shows Ruff and ty events up to the [`WARN`](tracing::Level::WARN).
+    /// Default output level. Only shows Ruff and Red Knot events up to the [`WARN`](tracing::Level::WARN).
    Default,

-    /// Enables verbose output. Emits Ruff and ty events up to the [`INFO`](tracing::Level::INFO).
+    /// Enables verbose output. Emits Ruff and Red Knot events up to the [`INFO`](tracing::Level::INFO).
    /// Corresponds to `-v`.
    Verbose,

-    /// Enables a more verbose tracing format and emits Ruff and ty events up to [`DEBUG`](tracing::Level::DEBUG).
+    /// Enables a more verbose tracing format and emits Ruff and Red Knot events up to [`DEBUG`](tracing::Level::DEBUG).
    /// Corresponds to `-vv`
    ExtraVerbose,

@@ -79,11 +79,11 @@ impl VerbosityLevel {
 pub(crate) fn setup_tracing(level: VerbosityLevel) -> anyhow::Result<TracingGuard> {
    use tracing_subscriber::prelude::*;

-    // The `TY_LOG` environment variable overrides the default log level.
-    let filter = if let Ok(log_env_variable) = std::env::var("TY_LOG") {
+    // The `RED_KNOT_LOG` environment variable overrides the default log level.
+    let filter = if let Ok(log_env_variable) = std::env::var("RED_KNOT_LOG") {
        EnvFilter::builder()
            .parse(log_env_variable)
-            .context("Failed to parse directives specified in TY_LOG environment variable.")?
+            .context("Failed to parse directives specified in RED_KNOT_LOG environment variable.")?
    } else {
        match level {
            VerbosityLevel::Default => {
@@ -93,9 +93,9 @@ pub(crate) fn setup_tracing(level: VerbosityLevel) -> anyhow::Result<TracingGuar
            level => {
                let level_filter = level.level_filter();

-                // Show info|debug|trace events, but allow `TY_LOG` to override
+                // Show info|debug|trace events, but allow `RED_KNOT_LOG` to override
                let filter = EnvFilter::default().add_directive(
-                    format!("ty={level_filter}")
+                    format!("red_knot={level_filter}")
                        .parse()
                        .expect("Hardcoded directive to be valid"),
                );
@@ -131,7 +131,7 @@ pub(crate) fn setup_tracing(level: VerbosityLevel) -> anyhow::Result<TracingGuar
    } else {
        let subscriber = registry.with(
            tracing_subscriber::fmt::layer()
-                .event_format(TyFormat {
+                .event_format(RedKnotFormat {
                    display_level: true,
                    display_timestamp: level.is_extra_verbose(),
                    show_spans: false,
@@ -147,7 +147,7 @@ pub(crate) fn setup_tracing(level: VerbosityLevel) -> anyhow::Result<TracingGuar
    })
 }

-#[expect(clippy::type_complexity)]
+#[allow(clippy::type_complexity)]
 fn setup_profile<S>() -> (
    Option<tracing_flame::FlameLayer<S, BufWriter<File>>>,
    Option<tracing_flame::FlushGuard<BufWriter<File>>>,
@@ -155,7 +155,7 @@ fn setup_profile<S>() -> (
 where
    S: Subscriber + for<'span> LookupSpan<'span>,
 {
-    if let Ok("1" | "true") = std::env::var("TY_LOG_PROFILE").as_deref() {
+    if let Ok("1" | "true") = std::env::var("RED_KNOT_LOG_PROFILE").as_deref() {
        let (layer, guard) = tracing_flame::FlameLayer::with_file("tracing.folded")
            .expect("Flame layer to be created");
        (Some(layer), Some(guard))
@@ -168,14 +168,14 @@ pub(crate) struct TracingGuard {
    _flame_guard: Option<tracing_flame::FlushGuard<BufWriter<File>>>,
 }

-struct TyFormat {
+struct RedKnotFormat {
    display_timestamp: bool,
    display_level: bool,
    show_spans: bool,
 }

 /// See <https://docs.rs/tracing-subscriber/0.3.18/src/tracing_subscriber/fmt/format/mod.rs.html#1026-1156>
-impl<S, N> FormatEvent<S, N> for TyFormat
+impl<S, N> FormatEvent<S, N> for RedKnotFormat
 where
    S: Subscriber + for<'a> LookupSpan<'a>,
    N: for<'a> FormatFields<'a> + 'static,
@@ -190,8 +190,8 @@ where
        let ansi = writer.has_ansi_escapes();

        if self.display_timestamp {
-            let timestamp = jiff::Zoned::now()
-                .strftime("%Y-%m-%d %H:%M:%S.%f")
+            let timestamp = chrono::Local::now()
+                .format("%Y-%m-%d %H:%M:%S.%f")
                .to_string();
            if ansi {
                write!(writer, "{} ", timestamp.dimmed())?;
@@ -199,7 +199,7 @@ where
                write!(
                    writer,
                    "{} ",
-                    jiff::Zoned::now().strftime("%Y-%m-%d %H:%M:%S.%f")
+                    chrono::Local::now().format("%Y-%m-%d %H:%M:%S.%f")
                )?;
            }
        }
--- a/crates/red_knot/src/main.rs
+++ b/crates/red_knot/src/main.rs
@@ -0,0 +1,370 @@
+use std::process::{ExitCode, Termination};
+use std::sync::Mutex;
+
+use anyhow::{anyhow, Context};
+use clap::Parser;
+use colored::Colorize;
+use crossbeam::channel as crossbeam_channel;
+use python_version::PythonVersion;
+use red_knot_python_semantic::SitePackages;
+use red_knot_server::run_server;
+use red_knot_workspace::db::ProjectDatabase;
+use red_knot_workspace::project::settings::Configuration;
+use red_knot_workspace::project::ProjectMetadata;
+use red_knot_workspace::watch;
+use red_knot_workspace::watch::ProjectWatcher;
+use ruff_db::diagnostic::Diagnostic;
+use ruff_db::system::{OsSystem, System, SystemPath, SystemPathBuf};
+use salsa::plumbing::ZalsaDatabase;
+
+use crate::logging::{setup_tracing, Verbosity};
+
+mod logging;
+mod python_version;
+mod verbosity;
+
+#[derive(Debug, Parser)]
+#[command(
+    author,
+    name = "red-knot",
+    about = "An extremely fast Python type checker."
+)]
+#[command(version)]
+struct Args {
+    #[command(subcommand)]
+    pub(crate) command: Option<Command>,
+
+    /// Run the command within the given project directory.
+    ///
+    /// All `pyproject.toml` files will be discovered by walking up the directory tree from the given project directory,
+    /// as will the project's virtual environment (`.venv`) unless the `venv-path` option is set.
+    ///
+    /// Other command-line arguments (such as relative paths) will be resolved relative to the current working directory.
+    #[arg(long, value_name = "PROJECT")]
+    project: Option<SystemPathBuf>,
+
+    /// Path to the virtual environment the project uses.
+    ///
+    /// 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")]
+    venv_path: Option<SystemPathBuf>,
+
+    /// Custom directory to use for stdlib typeshed stubs.
+    #[arg(long, value_name = "PATH", alias = "custom-typeshed-dir")]
+    typeshed: Option<SystemPathBuf>,
+
+    /// Additional path to use as a module-resolution source (can be passed multiple times).
+    #[arg(long, value_name = "PATH")]
+    extra_search_path: Option<Vec<SystemPathBuf>>,
+
+    /// Python version to assume when resolving types.
+    #[arg(long, value_name = "VERSION", alias = "target-version")]
+    python_version: Option<PythonVersion>,
+
+    #[clap(flatten)]
+    verbosity: Verbosity,
+
+    /// Run in watch mode by re-running whenever files change.
+    #[arg(long, short = 'W')]
+    watch: bool,
+}
+
+impl Args {
+    fn to_configuration(&self, cli_cwd: &SystemPath) -> Configuration {
+        let mut configuration = Configuration::default();
+
+        if let Some(python_version) = self.python_version {
+            configuration.python_version = Some(python_version.into());
+        }
+
+        if let Some(venv_path) = &self.venv_path {
+            configuration.search_paths.site_packages = Some(SitePackages::Derived {
+                venv_path: SystemPath::absolute(venv_path, cli_cwd),
+            });
+        }
+
+        if let Some(typeshed) = &self.typeshed {
+            configuration.search_paths.typeshed = Some(SystemPath::absolute(typeshed, cli_cwd));
+        }
+
+        if let Some(extra_search_paths) = &self.extra_search_path {
+            configuration.search_paths.extra_paths = extra_search_paths
+                .iter()
+                .map(|path| Some(SystemPath::absolute(path, cli_cwd)))
+                .collect();
+        }
+
+        configuration
+    }
+}
+
+#[derive(Debug, clap::Subcommand)]
+pub enum Command {
+    /// Start the language server
+    Server,
+}
+
+#[allow(clippy::print_stdout, clippy::unnecessary_wraps, clippy::print_stderr)]
+pub fn main() -> ExitStatus {
+    run().unwrap_or_else(|error| {
+        use std::io::Write;
+
+        // Use `writeln` instead of `eprintln` to avoid panicking when the stderr pipe is broken.
+        let mut stderr = std::io::stderr().lock();
+
+        // This communicates that this isn't a linter error but Red Knot itself hard-errored for
+        // some reason (e.g. failed to resolve the configuration)
+        writeln!(stderr, "{}", "Red Knot failed".red().bold()).ok();
+        // Currently we generally only see one error, but e.g. with io errors when resolving
+        // the configuration it is help to chain errors ("resolving configuration failed" ->
+        // "failed to read file: subdir/pyproject.toml")
+        for cause in error.chain() {
+            writeln!(stderr, "  {} {cause}", "Cause:".bold()).ok();
+        }
+
+        ExitStatus::Error
+    })
+}
+
+fn run() -> anyhow::Result<ExitStatus> {
+    let args = Args::parse_from(std::env::args());
+
+    if matches!(args.command, Some(Command::Server)) {
+        return run_server().map(|()| ExitStatus::Success);
+    }
+
+    let verbosity = args.verbosity.level();
+    countme::enable(verbosity.is_trace());
+    let _guard = setup_tracing(verbosity)?;
+
+    // The base path to which all CLI arguments are relative to.
+    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| {
+                anyhow!(
+                    "The current working directory `{}` contains non-Unicode characters. Red Knot only supports Unicode paths.",
+                    path.display()
+                )
+            })?
+    };
+
+    let cwd = args
+        .project
+        .as_ref()
+        .map(|cwd| {
+            if cwd.as_std_path().is_dir() {
+                Ok(SystemPath::absolute(cwd, &cli_base_path))
+            } else {
+                Err(anyhow!("Provided project path `{cwd}` is not a directory"))
+            }
+        })
+        .transpose()?
+        .unwrap_or_else(|| cli_base_path.clone());
+
+    let system = OsSystem::new(cwd.clone());
+    let cli_configuration = args.to_configuration(&cwd);
+    let workspace_metadata = ProjectMetadata::discover(
+        system.current_directory(),
+        &system,
+        Some(&cli_configuration),
+    )?;
+
+    // TODO: Use the `program_settings` to compute the key for the database's persistent
+    //   cache and load the cache if it exists.
+    let mut db = ProjectDatabase::new(workspace_metadata, system)?;
+
+    let (main_loop, main_loop_cancellation_token) = MainLoop::new(cli_configuration);
+
+    // Listen to Ctrl+C and abort the watch mode.
+    let main_loop_cancellation_token = Mutex::new(Some(main_loop_cancellation_token));
+    ctrlc::set_handler(move || {
+        let mut lock = main_loop_cancellation_token.lock().unwrap();
+
+        if let Some(token) = lock.take() {
+            token.stop();
+        }
+    })?;
+
+    let exit_status = if args.watch {
+        main_loop.watch(&mut db)?
+    } else {
+        main_loop.run(&mut db)
+    };
+
+    tracing::trace!("Counts for entire CLI run:\n{}", countme::get_all());
+
+    std::mem::forget(db);
+
+    Ok(exit_status)
+}
+
+#[derive(Copy, Clone)]
+pub enum ExitStatus {
+    /// Checking was successful and there were no errors.
+    Success = 0,
+
+    /// Checking was successful but there were errors.
+    Failure = 1,
+
+    /// Checking failed.
+    Error = 2,
+}
+
+impl Termination for ExitStatus {
+    fn report(self) -> ExitCode {
+        ExitCode::from(self as u8)
+    }
+}
+
+struct MainLoop {
+    /// Sender that can be used to send messages to the main loop.
+    sender: crossbeam_channel::Sender<MainLoopMessage>,
+
+    /// Receiver for the messages sent **to** the main loop.
+    receiver: crossbeam_channel::Receiver<MainLoopMessage>,
+
+    /// The file system watcher, if running in watch mode.
+    watcher: Option<ProjectWatcher>,
+
+    cli_configuration: Configuration,
+}
+
+impl MainLoop {
+    fn new(cli_configuration: Configuration) -> (Self, MainLoopCancellationToken) {
+        let (sender, receiver) = crossbeam_channel::bounded(10);
+
+        (
+            Self {
+                sender: sender.clone(),
+                receiver,
+                watcher: None,
+                cli_configuration,
+            },
+            MainLoopCancellationToken { sender },
+        )
+    }
+
+    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| {
+            sender.send(MainLoopMessage::ApplyChanges(event)).unwrap();
+        })?;
+
+        self.watcher = Some(ProjectWatcher::new(watcher, db));
+
+        self.run(db);
+
+        Ok(ExitStatus::Success)
+    }
+
+    fn run(mut self, db: &mut ProjectDatabase) -> ExitStatus {
+        self.sender.send(MainLoopMessage::CheckWorkspace).unwrap();
+
+        let result = self.main_loop(db);
+
+        tracing::debug!("Exiting main loop");
+
+        result
+    }
+
+    fn main_loop(&mut self, db: &mut ProjectDatabase) -> ExitStatus {
+        // Schedule the first check.
+        tracing::debug!("Starting main loop");
+
+        let mut revision = 0u64;
+
+        while let Ok(message) = self.receiver.recv() {
+            match message {
+                MainLoopMessage::CheckWorkspace => {
+                    let db = db.clone();
+                    let sender = self.sender.clone();
+
+                    // Spawn a new task that checks the project. This needs to be done in a separate thread
+                    // to prevent blocking the main loop here.
+                    rayon::spawn(move || {
+                        if let Ok(result) = db.check() {
+                            // Send the result back to the main loop for printing.
+                            sender
+                                .send(MainLoopMessage::CheckCompleted { result, revision })
+                                .unwrap();
+                        }
+                    });
+                }
+
+                MainLoopMessage::CheckCompleted {
+                    result,
+                    revision: check_revision,
+                } => {
+                    let has_diagnostics = !result.is_empty();
+                    if check_revision == revision {
+                        #[allow(clippy::print_stdout)]
+                        for diagnostic in result {
+                            println!("{}", diagnostic.display(db));
+                        }
+                    } else {
+                        tracing::debug!(
+                            "Discarding check result for outdated revision: current: {revision}, result revision: {check_revision}"
+                        );
+                    }
+
+                    if self.watcher.is_none() {
+                        return if has_diagnostics {
+                            ExitStatus::Failure
+                        } else {
+                            ExitStatus::Success
+                        };
+                    }
+
+                    tracing::trace!("Counts after last check:\n{}", countme::get_all());
+                }
+
+                MainLoopMessage::ApplyChanges(changes) => {
+                    revision += 1;
+                    // Automatically cancels any pending queries and waits for them to complete.
+                    db.apply_changes(changes, Some(&self.cli_configuration));
+                    if let Some(watcher) = self.watcher.as_mut() {
+                        watcher.update(db);
+                    }
+                    self.sender.send(MainLoopMessage::CheckWorkspace).unwrap();
+                }
+                MainLoopMessage::Exit => {
+                    // Cancel any pending queries and wait for them to complete.
+                    // TODO: Don't use Salsa internal APIs
+                    //  [Zulip-Thread](https://salsa.zulipchat.com/#narrow/stream/333573-salsa-3.2E0/topic/Expose.20an.20API.20to.20cancel.20other.20queries)
+                    let _ = db.zalsa_mut();
+                    return ExitStatus::Success;
+                }
+            }
+
+            tracing::debug!("Waiting for next main loop message.");
+        }
+
+        ExitStatus::Success
+    }
+}
+
+#[derive(Debug)]
+struct MainLoopCancellationToken {
+    sender: crossbeam_channel::Sender<MainLoopMessage>,
+}
+
+impl MainLoopCancellationToken {
+    fn stop(self) {
+        self.sender.send(MainLoopMessage::Exit).unwrap();
+    }
+}
+
+/// Message sent from the orchestrator to the main loop.
+#[derive(Debug)]
+enum MainLoopMessage {
+    CheckWorkspace,
+    CheckCompleted {
+        result: Vec<Box<dyn Diagnostic>>,
+        revision: u64,
+    },
+    ApplyChanges(Vec<watch::ChangeEvent>),
+    Exit,
+}
--- a/crates/red_knot/src/python_version.rs
+++ b/crates/red_knot/src/python_version.rs
@@ -40,7 +40,7 @@ impl std::fmt::Display for PythonVersion {
    }
 }

-impl From<PythonVersion> for ruff_python_ast::PythonVersion {
+impl From<PythonVersion> for red_knot_python_semantic::PythonVersion {
    fn from(value: PythonVersion) -> Self {
        match value {
            PythonVersion::Py37 => Self::PY37,
@@ -61,8 +61,8 @@ mod tests {
    #[test]
    fn same_default_as_python_version() {
        assert_eq!(
-            ruff_python_ast::PythonVersion::from(PythonVersion::default()),
-            ruff_python_ast::PythonVersion::default()
+            red_knot_python_semantic::PythonVersion::from(PythonVersion::default()),
+            red_knot_python_semantic::PythonVersion::default()
        );
    }
 }
--- a/crates/red_knot/src/verbosity.rs
+++ b/crates/red_knot/src/verbosity.rs
@@ -0,0 +1 @@
+
--- a/crates/red_knot/tests/file_watching.rs
+++ b/crates/red_knot/tests/file_watching.rs
--- a/crates/red_knot_python_semantic/Cargo.toml
+++ b/crates/red_knot_python_semantic/Cargo.toml
@@ -1,5 +1,5 @@
 [package]
-name = "ty_python_semantic"
+name = "red_knot_python_semantic"
 version = "0.0.0"
 publish = false
 authors = { workspace = true }
@@ -12,9 +12,9 @@ license = { workspace = true }

 [dependencies]
 ruff_db = { workspace = true }
-ruff_index = { workspace = true, features = ["salsa"] }
+ruff_index = { workspace = true }
 ruff_macros = { workspace = true }
-ruff_python_ast = { workspace = true, features = ["salsa"] }
+ruff_python_ast = { workspace = true }
 ruff_python_parser = { workspace = true }
 ruff_python_stdlib = { workspace = true }
 ruff_source_file = { workspace = true }
@@ -31,25 +31,22 @@ drop_bomb = { workspace = true }
 indexmap = { workspace = true }
 itertools = { workspace = true }
 ordermap = { workspace = true }
-salsa = { workspace = true, features = ["compact_str"] }
+salsa = { workspace = true }
 thiserror = { workspace = true }
 tracing = { workspace = true }
 rustc-hash = { workspace = true }
 hashbrown = { workspace = true }
-schemars = { workspace = true, optional = true }
 serde = { workspace = true, optional = true }
 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"] }
+ruff_db = { workspace = true, features = ["os", "testing"] }
 ruff_python_parser = { workspace = true }
-ty_test = { workspace = true }
-ty_vendored = { workspace = true }
+red_knot_test = { workspace = true }
+red_knot_vendored = { workspace = true }

 anyhow = { workspace = true }
 dir-test = { workspace = true }
@@ -59,7 +56,7 @@ quickcheck = { version = "1.0.3", default-features = false }
 quickcheck_macros = { version = "1.0.0" }

 [features]
-serde = ["ruff_db/serde", "dep:serde", "ruff_python_ast/serde"]
+serde = ["ruff_db/serde", "dep:serde"]

 [lints]
 workspace = true
--- a/crates/red_knot_python_semantic/build.rs
+++ b/crates/red_knot_python_semantic/build.rs
--- a/crates/red_knot_python_semantic/resources/README.md
+++ b/crates/red_knot_python_semantic/resources/README.md
@@ -1,4 +1,4 @@
 Markdown files within the `mdtest/` subdirectory are tests of type inference and type checking;
 executed by the `tests/mdtest.rs` integration test.

-See `crates/ty_test/README.md` for documentation of this test format.
+See `crates/red_knot_test/README.md` for documentation of this test format.
--- a/crates/red_knot_python_semantic/resources/mdtest/.mdformat.toml
+++ b/crates/red_knot_python_semantic/resources/mdtest/.mdformat.toml
--- a/crates/red_knot_python_semantic/resources/mdtest/annotations/annotated.md
+++ b/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[<class 'C'>, @Todo(Inference of subscript on special form), <class 'object'>]
+reveal_type(C.__mro__)  # revealed: tuple[Literal[C], Unknown, Literal[object]]
 ```

 ### Not parameterized
@@ -88,5 +90,5 @@ from typing_extensions import Annotated
 # error: [invalid-base]
 class C(Annotated): ...

-reveal_type(C.__mro__)  # revealed: tuple[<class 'C'>, Unknown, <class 'object'>]
+reveal_type(C.__mro__)  # revealed: tuple[Literal[C], Unknown, Literal[object]]
 ```
--- a/crates/red_knot_python_semantic/resources/mdtest/annotations/any.md
+++ b/crates/red_knot_python_semantic/resources/mdtest/annotations/any.md
@@ -0,0 +1,83 @@
+# Any
+
+## Annotation
+
+`typing.Any` is a way to name the Any type.
+
+```py
+from typing import Any
+
+x: Any = 1
+x = "foo"
+
+def f():
+    reveal_type(x)  # revealed: Any
+```
+
+## Aliased to a different name
+
+If you alias `typing.Any` to another name, we still recognize that as a spelling of the Any type.
+
+```py
+from typing import Any as RenamedAny
+
+x: RenamedAny = 1
+x = "foo"
+
+def f():
+    reveal_type(x)  # revealed: Any
+```
+
+## Shadowed class
+
+If you define your own class named `Any`, using that in a type expression refers to your class, and
+isn't a spelling of the Any type.
+
+```py
+class Any: ...
+
+x: Any
+
+def f():
+    reveal_type(x)  # revealed: Any
+
+# This verifies that we're not accidentally seeing typing.Any, since str is assignable
+# to that but not to our locally defined class.
+y: Any = "not an Any"  # error: [invalid-assignment]
+```
+
+## Subclass
+
+The spec allows you to define subclasses of `Any`.
+
+TODO: Handle assignments correctly. `Subclass` has an unknown superclass, which might be `int`. The
+assignment to `x` should not be allowed, even when the unknown superclass is `int`. The assignment
+to `y` should be allowed, since `Subclass` might have `int` as a superclass, and is therefore
+assignable to `int`.
+
+```py
+from typing import Any
+
+class Subclass(Any): ...
+
+reveal_type(Subclass.__mro__)  # revealed: tuple[Literal[Subclass], Any, Literal[object]]
+
+x: Subclass = 1  # error: [invalid-assignment]
+# TODO: no diagnostic
+y: int = Subclass()  # error: [invalid-assignment]
+
+def _(s: Subclass):
+    reveal_type(s)  # revealed: Subclass
+```
+
+## Invalid
+
+`Any` cannot be parameterized:
+
+```py
+from typing import Any
+
+# error: [invalid-type-form] "Type `typing.Any` expected no type parameter"
+def f(x: Any[int]):
+    reveal_type(x)  # revealed: Unknown
+```
--- a/crates/red_knot_python_semantic/resources/mdtest/annotations/literal.md
+++ b/crates/red_knot_python_semantic/resources/mdtest/annotations/literal.md
@@ -1,6 +1,6 @@
 # Literal

-<https://typing.python.org/en/latest/spec/literal.html#literals>
+<https://typing.readthedocs.io/en/latest/spec/literal.html#literals>

 ## Parameterization

@@ -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: Literal[0]

 # error: [invalid-type-form]
 invalid1: Literal[3 + 4]
@@ -68,7 +68,7 @@ def x(
    a3: Literal[Literal["w"], Literal["r"], Literal[Literal["w+"]]],
    a4: Literal[True] | Literal[1, 2] | Literal["foo"],
 ):
-    reveal_type(a1)  # revealed: Literal[1, 2, 3, 5, "foo"] | None
+    reveal_type(a1)  # revealed: Literal[1, 2, 3, "foo", 5] | None
    reveal_type(a2)  # revealed: Literal["w", "r"]
    reveal_type(a3)  # revealed: Literal["w", "r", "w+"]
    reveal_type(a4)  # revealed: Literal[True, 1, 2, "foo"]
@@ -106,9 +106,9 @@ def union_example(
        Literal["B"],
        Literal[True],
        None,
-    ],
+    ]
 ):
-    reveal_type(x)  # revealed: Unknown | Literal[-1, 0, 1, "A", "B", "foo", "bar", b"A", b"\x00", b"\x07", True] | None
+    reveal_type(x)  # revealed: Unknown | Literal[-1, "A", b"A", b"\x00", b"\x07", 0, 1, "B", "foo", "bar", True] | None
 ```

 ## Detecting Literal outside typing and typing_extensions
@@ -116,9 +116,7 @@ def union_example(
 Only Literal that is defined in typing and typing_extension modules is detected as the special
 Literal.

-`other.pyi`:
-
-```pyi
+```pyi path=other.pyi
 from typing import _SpecialForm

 Literal: _SpecialForm
@@ -127,17 +125,10 @@ 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():
-    reveal_type(a1)  # revealed: @Todo(unknown type subscript)
+    reveal_type(a1)  # revealed: @Todo(generics)
 ```

 ## Detecting typing_extensions.Literal
@@ -156,7 +147,7 @@ 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
 ```
--- a/crates/red_knot_python_semantic/resources/mdtest/annotations/literal_string.md
+++ b/crates/red_knot_python_semantic/resources/mdtest/annotations/literal_string.md
@@ -38,12 +38,8 @@ bad_nesting: Literal[LiteralString]  # error: [invalid-type-form]
 ```py
 from typing_extensions import LiteralString

-# error: [invalid-type-form]
-a: LiteralString[str]
-
-# error: [invalid-type-form]
-# error: [unresolved-reference] "Name `foo` used when not defined"
-b: LiteralString["foo"]
+a: LiteralString[str]  # error: [invalid-type-form]
+b: LiteralString["foo"]  # error: [invalid-type-form]
 ```

 ### As a base class
@@ -76,11 +72,13 @@ reveal_type(baz)  # revealed: Literal["bazfoo"]
 qux = (foo, bar)
 reveal_type(qux)  # revealed: tuple[Literal["foo"], Literal["bar"]]

-reveal_type(foo.join(qux))  # revealed: LiteralString
+# TODO: Infer "LiteralString"
+reveal_type(foo.join(qux))  # revealed: @Todo(Attribute access on `StringLiteral` types)

 template: LiteralString = "{}, {}"
 reveal_type(template)  # revealed: Literal["{}, {}"]
-reveal_type(template.format(foo, bar))  # revealed: LiteralString
+# TODO: Infer `LiteralString`
+reveal_type(template.format(foo, bar))  # revealed: @Todo(Attribute access on `StringLiteral` types)
 ```

 ### Assignability
@@ -149,4 +147,4 @@ def f():
    reveal_type(x)  # revealed: LiteralString
 ```

-[1]: https://typing.python.org/en/latest/spec/literal.html#literalstring
+[1]: https://typing.readthedocs.io/en/latest/spec/literal.html#literalstring
--- a/crates/red_knot_python_semantic/resources/mdtest/annotations/never.md
+++ b/crates/red_knot_python_semantic/resources/mdtest/annotations/never.md
--- a/crates/red_knot_python_semantic/resources/mdtest/annotations/optional.md
+++ b/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
-```
--- a/crates/red_knot_python_semantic/resources/mdtest/annotations/starred.md
+++ b/crates/red_knot_python_semantic/resources/mdtest/annotations/starred.md
@@ -1,10 +1,5 @@
 # Starred expression annotations

-```toml
-[environment]
-python-version = "3.11"
-```
-
 Type annotations for `*args` can be starred expressions themselves:

 ```py
--- a/crates/red_knot_python_semantic/resources/mdtest/annotations/stdlib_typing_aliases.md
+++ b/crates/red_knot_python_semantic/resources/mdtest/annotations/stdlib_typing_aliases.md
@@ -0,0 +1,127 @@
+# Typing-module aliases to other stdlib classes
+
+The `typing` module has various aliases to other stdlib classes. These are a legacy feature, but
+still need to be supported by a type checker.
+
+## Correspondence
+
+All of the following symbols can be mapped one-to-one with the actual type:
+
+```py
+import typing
+
+def f(
+    list_bare: typing.List,
+    list_parametrized: typing.List[int],
+    dict_bare: typing.Dict,
+    dict_parametrized: typing.Dict[int, str],
+    set_bare: typing.Set,
+    set_parametrized: typing.Set[int],
+    frozen_set_bare: typing.FrozenSet,
+    frozen_set_parametrized: typing.FrozenSet[str],
+    chain_map_bare: typing.ChainMap,
+    chain_map_parametrized: typing.ChainMap[int],
+    counter_bare: typing.Counter,
+    counter_parametrized: typing.Counter[int],
+    default_dict_bare: typing.DefaultDict,
+    default_dict_parametrized: typing.DefaultDict[str, int],
+    deque_bare: typing.Deque,
+    deque_parametrized: typing.Deque[str],
+    ordered_dict_bare: typing.OrderedDict,
+    ordered_dict_parametrized: typing.OrderedDict[int, str],
+):
+    reveal_type(list_bare)  # revealed: list
+    reveal_type(list_parametrized)  # revealed: list
+
+    reveal_type(dict_bare)  # revealed: dict
+    reveal_type(dict_parametrized)  # revealed: dict
+
+    reveal_type(set_bare)  # revealed: set
+    reveal_type(set_parametrized)  # revealed: set
+
+    reveal_type(frozen_set_bare)  # revealed: frozenset
+    reveal_type(frozen_set_parametrized)  # revealed: frozenset
+
+    reveal_type(chain_map_bare)  # revealed: ChainMap
+    reveal_type(chain_map_parametrized)  # revealed: ChainMap
+
+    reveal_type(counter_bare)  # revealed: Counter
+    reveal_type(counter_parametrized)  # revealed: Counter
+
+    reveal_type(default_dict_bare)  # revealed: defaultdict
+    reveal_type(default_dict_parametrized)  # revealed: defaultdict
+
+    reveal_type(deque_bare)  # revealed: deque
+    reveal_type(deque_parametrized)  # revealed: deque
+
+    reveal_type(ordered_dict_bare)  # revealed: OrderedDict
+    reveal_type(ordered_dict_parametrized)  # revealed: OrderedDict
+```
+
+## Inheritance
+
+The aliases can be inherited from. Some of these are still partially or wholly TODOs.
+
+```py
+import typing
+
+####################
+### Built-ins
+
+class ListSubclass(typing.List): ...
+
+# 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): ...
+
+# TODO: should have `Generic`, should not have `Unknown`
+# revealed: tuple[Literal[DictSubclass], Literal[dict], Unknown, Literal[object]]
+reveal_type(DictSubclass.__mro__)
+
+class SetSubclass(typing.Set): ...
+
+# 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): ...
+
+# TODO: should have `Generic`, should not have `Unknown`
+# revealed: tuple[Literal[FrozenSetSubclass], Literal[frozenset], Unknown, Literal[object]]
+reveal_type(FrozenSetSubclass.__mro__)
+
+####################
+### `collections`
+
+class ChainMapSubclass(typing.ChainMap): ...
+
+# TODO: Should be (ChainMapSubclass, ChainMap, MutableMapping, Mapping, Collection, Sized, Iterable, Container, Generic, object)
+# revealed: tuple[Literal[ChainMapSubclass], Literal[ChainMap], Unknown, Literal[object]]
+reveal_type(ChainMapSubclass.__mro__)
+
+class CounterSubclass(typing.Counter): ...
+
+# TODO: Should be (CounterSubclass, Counter, dict, MutableMapping, Mapping, Collection, Sized, Iterable, Container, Generic, object)
+# revealed: tuple[Literal[CounterSubclass], Literal[Counter], Unknown, Literal[object]]
+reveal_type(CounterSubclass.__mro__)
+
+class DefaultDictSubclass(typing.DefaultDict): ...
+
+# TODO: Should be (DefaultDictSubclass, defaultdict, dict, MutableMapping, Mapping, Collection, Sized, Iterable, Container, Generic, object)
+# revealed: tuple[Literal[DefaultDictSubclass], Literal[defaultdict], Unknown, Literal[object]]
+reveal_type(DefaultDictSubclass.__mro__)
+
+class DequeSubclass(typing.Deque): ...
+
+# 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): ...
+
+# TODO: Should be (OrderedDictSubclass, OrderedDict, dict, MutableMapping, Mapping, Collection, Sized, Iterable, Container, Generic, object)
+# revealed: tuple[Literal[OrderedDictSubclass], Literal[OrderedDict], Unknown, Literal[object]]
+reveal_type(OrderedDictSubclass.__mro__)
+```
--- a/crates/red_knot_python_semantic/resources/mdtest/annotations/string.md
+++ b/crates/red_knot_python_semantic/resources/mdtest/annotations/string.md
@@ -105,7 +105,7 @@ def f1(
 from typing import Literal

 def f(v: Literal["a", r"b", b"c", "d" "e", "\N{LATIN SMALL LETTER F}", "\x67", """h"""]):
-    reveal_type(v)  # revealed: Literal["a", "b", "de", "f", "g", "h", b"c"]
+    reveal_type(v)  # revealed: Literal["a", "b", b"c", "de", "f", "g", "h"]
 ```

 ## Class variables
@@ -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
--- a/crates/red_knot_python_semantic/resources/mdtest/annotations/union.md
+++ b/crates/red_knot_python_semantic/resources/mdtest/annotations/union.md
@@ -2,16 +2,16 @@

 ## Annotation

-`typing.Union` can be used to construct union types in the same way as the `|` operator.
+`typing.Union` can be used to construct union types same as `|` operator.

 ```py
 from typing import Union

 a: Union[int, str]
 a1: Union[int, bool]
-a2: Union[int, Union[bytes, str]]
+a2: Union[int, Union[float, str]]
 a3: Union[int, None]
-a4: Union[Union[bytes, str]]
+a4: Union[Union[float, str]]
 a5: Union[int]
 a6: Union[()]

@@ -21,11 +21,11 @@ def f():
    # Since bool is a subtype of int we simplify to int here. But we do allow assigning boolean values (see below).
    # revealed: int
    reveal_type(a1)
-    # revealed: int | bytes | str
+    # revealed: int | float | str
    reveal_type(a2)
    # revealed: int | None
    reveal_type(a3)
-    # revealed: bytes | str
+    # revealed: float | str
    reveal_type(a4)
    # revealed: int
    reveal_type(a5)
@@ -59,30 +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
-```
-
-## Implicit type aliases using new-style unions
-
-We don't recognise these as type aliases yet, but we also don't emit false-positive diagnostics if
-you use them in type expressions:
-
-```toml
-[environment]
-python-version = "3.10"
-```
-
-```py
-X = int | str
-
-def f(y: X):
-    reveal_type(y)  # revealed: @Todo(Support for `types.UnionType` instances in type expressions)
-```
--- a/crates/red_knot_python_semantic/resources/mdtest/annotations/unsupported_special_forms.md
+++ b/crates/red_knot_python_semantic/resources/mdtest/annotations/unsupported_special_forms.md
@@ -0,0 +1,71 @@
+# Unsupported special forms
+
+## Not yet supported
+
+Several special forms are unsupported by red-knot currently. However, we also don't emit
+false-positive errors if you use one in an annotation:
+
+```py
+from typing_extensions import Self, TypeVarTuple, Unpack, TypeGuard, TypeIs, Concatenate, ParamSpec, TypeAlias, Callable, TypeVar
+
+P = ParamSpec("P")
+Ts = TypeVarTuple("Ts")
+R_co = TypeVar("R_co", covariant=True)
+
+Alias: TypeAlias = int
+
+def f(*args: Unpack[Ts]) -> tuple[Unpack[Ts]]:
+    # TODO: should understand the annotation
+    reveal_type(args)  # revealed: tuple
+
+    reveal_type(Alias)  # revealed: @Todo(Unsupported or invalid type in a type expression)
+
+def g() -> TypeGuard[int]: ...
+def h() -> TypeIs[int]: ...
+def i(callback: Callable[Concatenate[int, P], R_co], *args: P.args, **kwargs: P.kwargs) -> R_co:
+    # TODO: should understand the annotation
+    reveal_type(args)  # revealed: tuple
+
+    # TODO: should understand the annotation
+    reveal_type(kwargs)  # revealed: dict
+
+    return callback(42, *args, **kwargs)
+
+class Foo:
+    def method(self, x: Self):
+        reveal_type(x)  # revealed: @Todo(Unsupported or invalid type in a type expression)
+```
+
+## Inheritance
+
+You can't inherit from most of these. `typing.Callable` is an exception.
+
+```py
+from typing import Callable
+from typing_extensions import Self, Unpack, TypeGuard, TypeIs, Concatenate
+
+class A(Self): ...  # error: [invalid-base]
+class B(Unpack): ...  # error: [invalid-base]
+class C(TypeGuard): ...  # error: [invalid-base]
+class D(TypeIs): ...  # error: [invalid-base]
+class E(Concatenate): ...  # error: [invalid-base]
+class F(Callable): ...
+
+reveal_type(F.__mro__)  # revealed: tuple[Literal[F], @Todo(Support for Callable as a base class), Literal[object]]
+```
+
+## Subscriptability
+
+Some of these are not subscriptable:
+
+```py
+from typing_extensions import Self, TypeAlias
+
+X: TypeAlias[T] = int  # error: [invalid-type-form]
+
+class Foo[T]:
+    # error: [invalid-type-form] "Special form `typing.Self` expected no type parameter"
+    # error: [invalid-type-form] "Special form `typing.Self` expected no type parameter"
+    def method(self: Self[int]) -> Self[int]:
+        reveal_type(self)  # revealed: Unknown
+```
--- a/crates/red_knot_python_semantic/resources/mdtest/annotations/unsupported_type_qualifiers.md
+++ b/crates/red_knot_python_semantic/resources/mdtest/annotations/unsupported_type_qualifiers.md
@@ -0,0 +1,34 @@
+# Unsupported type qualifiers
+
+## 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:
+
+```py
+from typing_extensions import Final, Required, NotRequired, ReadOnly, TypedDict
+
+X: Final = 42
+Y: Final[int] = 42
+
+# TODO: `TypedDict` is actually valid as a base
+# error: [invalid-base]
+class Bar(TypedDict):
+    x: Required[int]
+    y: NotRequired[str]
+    z: ReadOnly[bytes]
+```
+
+## Inheritance
+
+You can't inherit from a type qualifier.
+
+```py
+from typing_extensions import Final, ClassVar, Required, NotRequired, ReadOnly
+
+class A(Final): ...  # error: [invalid-base]
+class B(ClassVar): ...  # error: [invalid-base]
+class C(Required): ...  # error: [invalid-base]
+class D(NotRequired): ...  # error: [invalid-base]
+class E(ReadOnly): ...  # error: [invalid-base]
+```
--- a/crates/red_knot_python_semantic/resources/mdtest/assignment/annotations.md
+++ b/crates/red_knot_python_semantic/resources/mdtest/assignment/annotations.md
@@ -25,14 +25,7 @@ x = "foo"  # error: [invalid-assignment] "Object of type `Literal["foo"]` is not

 ## Tuple annotations are understood

-```toml
-[environment]
-python-version = "3.12"
-```
-
-`module.py`:
-
-```py
+```py path=module.py
 from typing_extensions import Unpack

 a: tuple[()] = ()
@@ -47,9 +40,7 @@ i: tuple[str | int, str | int] = (42, 42)
 j: tuple[str | int] = (42,)
 ```

-`script.py`:
-
-```py
+```py path=script.py
 from module import a, b, c, d, e, f, g, h, i, j

 reveal_type(a)  # revealed: tuple[()]
@@ -57,11 +48,13 @@ 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(specialized non-generic class), @Todo(specialized non-generic class)]
+
+# 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]
@@ -121,7 +114,7 @@ reveal_type(x)  # revealed: Foo

 ## Annotations in stub files are deferred

-```pyi
+```pyi path=main.pyi
 x: Foo

 class Foo: ...
@@ -132,7 +125,7 @@ reveal_type(x)  # revealed: Foo

 ## Annotated assignments in stub files are inferred correctly

-```pyi
+```pyi path=main.pyi
 x: int = 1
 reveal_type(x) # revealed: Literal[1]
 ```
--- a/crates/red_knot_python_semantic/resources/mdtest/assignment/augmented.md
+++ b/crates/red_knot_python_semantic/resources/mdtest/assignment/augmented.md
@@ -9,11 +9,7 @@ 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]]
+reveal_type(x)  # revealed: float
 ```

 ## Dunder methods
@@ -28,12 +24,12 @@ x -= 1
 reveal_type(x)  # revealed: str

 class C:
-    def __iadd__(self, other: str) -> int:
-        return 1
+    def __iadd__(self, other: str) -> float:
+        return 1.0

 x = C()
 x += "Hello"
-reveal_type(x)  # revealed: int
+reveal_type(x)  # revealed: float
 ```

 ## Unsupported types
@@ -44,7 +40,7 @@ class C:
        return 42

 x = C()
-# error: [unsupported-operator] "Operator `-=` is unsupported between objects of type `C` and `Literal[1]`"
+# error: [invalid-argument-type]
 x -= 1

 reveal_type(x)  # revealed: int
@@ -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
@@ -133,10 +130,10 @@ def _(flag: bool):
    if flag:
        f = Foo()
    else:
-        f = 42
+        f = 42.0
    f += 12

-    reveal_type(f)  # revealed: str | Literal[54]
+    reveal_type(f)  # revealed: str | float
 ```

 ## Partially bound target union with `__add__`
@@ -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
-```
--- a/crates/red_knot_python_semantic/resources/mdtest/assignment/multi_target.md
+++ b/crates/red_knot_python_semantic/resources/mdtest/assignment/multi_target.md
--- a/crates/red_knot_python_semantic/resources/mdtest/assignment/unbound.md
+++ b/crates/red_knot_python_semantic/resources/mdtest/assignment/unbound.md
--- a/crates/red_knot_python_semantic/resources/mdtest/assignment/walrus.md
+++ b/crates/red_knot_python_semantic/resources/mdtest/assignment/walrus.md
--- a/crates/red_knot_python_semantic/resources/mdtest/attributes.md
+++ b/crates/red_knot_python_semantic/resources/mdtest/attributes.md
@@ -0,0 +1,503 @@
+# Attributes
+
+Tests for attribute access on various kinds of types.
+
+## Class and instance variables
+
+### Pure instance variables
+
+#### Variable only declared/bound in `__init__`
+
+Variables only declared and/or bound in `__init__` are pure instance variables. They cannot be
+accessed on the class itself.
+
+```py
+class C:
+    def __init__(self, value2: int, flag: bool = False) -> None:
+        # bound but not declared
+        self.pure_instance_variable1 = "value set in __init__"
+
+        # bound but not declared - with type inferred from parameter
+        self.pure_instance_variable2 = value2
+
+        # declared but not bound
+        self.pure_instance_variable3: bytes
+
+        # declared and bound
+        self.pure_instance_variable4: bool = True
+
+        # possibly undeclared/unbound
+        if flag:
+            self.pure_instance_variable5: str = "possibly set in __init__"
+
+c_instance = C(1)
+
+# TODO: should be `Literal["value set in __init__"]`, or `Unknown | Literal[…]` to allow
+# assignments to this unannotated attribute from other scopes.
+reveal_type(c_instance.pure_instance_variable1)  # revealed: @Todo(instance attributes)
+
+# TODO: should be `int`
+reveal_type(c_instance.pure_instance_variable2)  # revealed: @Todo(instance attributes)
+
+# TODO: should be `bytes`
+reveal_type(c_instance.pure_instance_variable3)  # revealed: @Todo(instance attributes)
+
+# TODO: should be `bool`
+reveal_type(c_instance.pure_instance_variable4)  # revealed: @Todo(instance attributes)
+
+# TODO: should be `str`
+# We probably don't want to emit a diagnostic for this being possibly undeclared/unbound.
+# mypy and pyright do not show an error here.
+reveal_type(c_instance.pure_instance_variable5)  # revealed: @Todo(instance attributes)
+
+# TODO: If we choose to infer a precise `Literal[…]` type for the instance attribute (see
+# above), this should be an error: incompatible types in assignment. If we choose to infer
+# a gradual `Unknown | Literal[…]` type, this assignment is fine.
+c_instance.pure_instance_variable1 = "value set on instance"
+
+# TODO: this should be an error (incompatible types in assignment)
+c_instance.pure_instance_variable2 = "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] "Type `Literal[C]` has no attribute `pure_instance_variable1`"
+reveal_type(C.pure_instance_variable1)  # 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"
+C.pure_instance_variable1 = "overwritten on class"
+
+c_instance.pure_instance_variable4 = False
+
+# TODO: After this assignment to the attribute within this scope, we may eventually want to narrow
+# the `bool` type (see above) for this instance variable to `Literal[False]` here. This is unsound
+# in general (we don't know what else happened to `c_instance` between the assignment and the use
+# here), but mypy and pyright support this. In conclusion, this could be `bool` but should probably
+# be `Literal[False]`.
+reveal_type(c_instance.pure_instance_variable4)  # revealed: @Todo(instance attributes)
+```
+
+#### Variable declared in class body and declared/bound in `__init__`
+
+The same rule applies even if the variable is *declared* (not bound!) in the class body: it is still
+a pure instance variable.
+
+```py
+class C:
+    pure_instance_variable: str
+
+    def __init__(self) -> None:
+        self.pure_instance_variable = "value set in __init__"
+
+c_instance = C()
+
+# TODO: should be `str`
+reveal_type(c_instance.pure_instance_variable)  # revealed: @Todo(instance attributes)
+
+# 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.pure_instance_variable)  # revealed: str
+
+# TODO: same as above. We plan to emit a diagnostic here, even if both mypy
+# and pyright allow this.
+C.pure_instance_variable = "overwritten on class"
+
+# TODO: this should be an error (incompatible types in assignment)
+c_instance.pure_instance_variable = 1
+```
+
+#### Variable only defined in unrelated method
+
+We also recognize pure instance variables if they are defined in a method that is not `__init__`.
+
+```py
+class C:
+    def set_instance_variable(self) -> None:
+        self.pure_instance_variable = "value set in method"
+
+c_instance = C()
+
+# Not that we would use this in static analysis, but for a more realistic example, let's actually
+# call the method, so that the attribute is bound if this example is actually run.
+c_instance.set_instance_variable()
+
+# TODO: should be `Literal["value set in method"]` or `Unknown | Literal[…]` (see above).
+reveal_type(c_instance.pure_instance_variable)  # revealed: @Todo(instance attributes)
+
+# TODO: We already show an error here, but the message might be improved?
+# error: [unresolved-attribute]
+reveal_type(C.pure_instance_variable)  # revealed: Unknown
+
+# TODO: this should be an error
+C.pure_instance_variable = "overwritten on class"
+```
+
+#### Variable declared in class body and not bound anywhere
+
+If a variable is declared in the class body but not bound anywhere, we still consider it a pure
+instance variable and allow access to it via instances.
+
+```py
+class C:
+    pure_instance_variable: str
+
+c_instance = C()
+
+# TODO: should be 'str'
+reveal_type(c_instance.pure_instance_variable)  # revealed: @Todo(instance attributes)
+
+# 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.pure_instance_variable)  # revealed: str
+
+# TODO: mypy and pyright do not show an error here, but we plan to emit one.
+C.pure_instance_variable = "overwritten on class"
+```
+
+### Pure class variables (`ClassVar`)
+
+#### Annotated with `ClassVar` type qualifier
+
+Class variables annotated with the [`typing.ClassVar`] type qualifier are pure class variables. They
+cannot be overwritten on instances, but they can be accessed on instances.
+
+For more details, see the [typing spec on `ClassVar`].
+
+```py
+from typing import ClassVar
+
+class C:
+    pure_class_variable1: ClassVar[str] = "value in class body"
+    pure_class_variable2: ClassVar = 1
+
+reveal_type(C.pure_class_variable1)  # revealed: str
+
+# TODO: this should be `Literal[1]`, or `Unknown | Literal[1]`.
+reveal_type(C.pure_class_variable2)  # revealed: @Todo(Unsupported or invalid type in a type expression)
+
+c_instance = C()
+
+# TODO: This should be `str`. It is okay to access a pure class variable on an instance.
+reveal_type(c_instance.pure_class_variable1)  # revealed: @Todo(instance attributes)
+
+# TODO: should raise an error. It is not allowed to reassign a pure class variable on an instance.
+c_instance.pure_class_variable1 = "value set on instance"
+
+C.pure_class_variable1 = "overwritten on class"
+
+# TODO: should raise an error (incompatible types in assignment)
+C.pure_class_variable1 = 1
+
+class Subclass(C):
+    pure_class_variable1: ClassVar[str] = "overwritten on subclass"
+
+reveal_type(Subclass.pure_class_variable1)  # revealed: str
+```
+
+#### Variable only mentioned in a class method
+
+We also consider a class variable to be a pure class variable if it is only mentioned in a class
+method.
+
+```py
+class C:
+    @classmethod
+    def class_method(cls):
+        cls.pure_class_variable = "value set in class method"
+
+# for a more realistic example, let's actually call the method
+C.class_method()
+
+# TODO: We currently plan to support this and show no error here.
+# mypy shows an error here, pyright does not.
+# error: [unresolved-attribute]
+reveal_type(C.pure_class_variable)  # revealed: Unknown
+
+C.pure_class_variable = "overwritten on class"
+
+# TODO: should be `Literal["overwritten on class"]`
+# error: [unresolved-attribute]
+reveal_type(C.pure_class_variable)  # revealed: Unknown
+
+c_instance = C()
+# TODO: should be `Literal["overwritten on class"]`
+reveal_type(c_instance.pure_class_variable)  # revealed: @Todo(instance attributes)
+
+# TODO: should raise an error.
+c_instance.pure_class_variable = "value set on instance"
+```
+
+### Instance variables with class-level default values
+
+These are instance attributes, but the fact that we can see that they have a binding (not a
+declaration) in the class body means that reading the value from the class directly is also
+permitted. This is the only difference for these attributes as opposed to "pure" instance
+attributes.
+
+#### Basic
+
+```py
+class C:
+    variable_with_class_default: str = "value in class body"
+
+    def instance_method(self):
+        self.variable_with_class_default = "value set in instance method"
+
+reveal_type(C.variable_with_class_default)  # revealed: str
+
+c_instance = C()
+
+# TODO: should be `str`
+reveal_type(c_instance.variable_with_class_default)  # revealed: @Todo(instance attributes)
+
+c_instance.variable_with_class_default = "value set on instance"
+
+reveal_type(C.variable_with_class_default)  # revealed: str
+
+# TODO: Could be Literal["value set on instance"], or still `str` if we choose not to
+# narrow the type.
+reveal_type(c_instance.variable_with_class_default)  # revealed: @Todo(instance attributes)
+
+C.variable_with_class_default = "overwritten on class"
+
+# TODO: Could be `Literal["overwritten on class"]`, or still `str` if we choose not to
+# narrow the type.
+reveal_type(C.variable_with_class_default)  # revealed: str
+
+# TODO: should still be `Literal["value set on instance"]`, or `str`.
+reveal_type(c_instance.variable_with_class_default)  # revealed: @Todo(instance attributes)
+```
+
+## Union of attributes
+
+```py
+def _(flag: bool):
+    if flag:
+        class C1:
+            x = 1
+
+    else:
+        class C1:
+            x = 2
+
+    class C2:
+        if flag:
+            x = 3
+        else:
+            x = 4
+
+    reveal_type(C1.x)  # revealed: Literal[1, 2]
+    reveal_type(C2.x)  # revealed: Literal[3, 4]
+```
+
+## Inherited class attributes
+
+### Basic
+
+```py
+class A:
+    X = "foo"
+
+class B(A): ...
+class C(B): ...
+
+reveal_type(C.X)  # revealed: Literal["foo"]
+```
+
+### Multiple inheritance
+
+```py
+class O: ...
+
+class F(O):
+    X = 56
+
+class E(O):
+    X = 42
+
+class D(O): ...
+class C(D, F): ...
+class B(E, D): ...
+class A(B, C): ...
+
+# revealed: tuple[Literal[A], Literal[B], Literal[E], Literal[C], Literal[D], Literal[F], Literal[O], Literal[object]]
+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: Literal[42]
+```
+
+## 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: Literal[1, 3]
+```
+
+### 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: Literal[1, 2, 3]
+```
+
+### 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
+```
+
+## Objects of all types have a `__class__` method
+
+```py
+import typing_extensions
+
+reveal_type(typing_extensions.__class__)  # revealed: Literal[ModuleType]
+
+a = 42
+reveal_type(a.__class__)  # revealed: Literal[int]
+
+b = "42"
+reveal_type(b.__class__)  # revealed: Literal[str]
+
+c = b"42"
+reveal_type(c.__class__)  # revealed: Literal[bytes]
+
+d = True
+reveal_type(d.__class__)  # revealed: Literal[bool]
+
+e = (42, 42)
+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(b.__class__)  # revealed: Literal[str]
+    reveal_type(c.__class__)  # 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,
+    # as `c` could be some subclass of `str` with a custom metaclass.
+    # All we know is that the metaclass must be a (non-strict) subclass of `type`.
+    reveal_type(d.__class__)  # revealed: type[type]
+
+reveal_type(f.__class__)  # revealed: Literal[FunctionType]
+
+class Foo: ...
+
+reveal_type(Foo.__class__)  # revealed: Literal[type]
+```
+
+## Literal types
+
+### Function-literal attributes
+
+Most attribute accesses on function-literal types are delegated to `types.FunctionType`, since all
+functions are instances of that class:
+
+```py path=a.py
+def f(): ...
+
+reveal_type(f.__defaults__)  # revealed: @Todo(instance attributes)
+reveal_type(f.__kwdefaults__)  # revealed: @Todo(instance attributes)
+```
+
+Some attributes are special-cased, however:
+
+```py path=b.py
+def f(): ...
+
+reveal_type(f.__get__)  # revealed: @Todo(`__get__` method on functions)
+reveal_type(f.__call__)  # revealed: @Todo(`__call__` method on functions)
+```
+
+### Int-literal attributes
+
+Most attribute accesses on int-literal types are delegated to `builtins.int`, since all literal
+integers are instances of that class:
+
+```py path=a.py
+reveal_type((2).bit_length)  # revealed: @Todo(instance attributes)
+reveal_type((2).denominator)  # revealed: @Todo(instance attributes)
+```
+
+Some attributes are special-cased, however:
+
+```py path=b.py
+reveal_type((2).numerator)  # revealed: Literal[2]
+reveal_type((2).real)  # revealed: Literal[2]
+```
+
+### Bool-literal attributes
+
+Most attribute accesses on bool-literal types are delegated to `builtins.bool`, since all literal
+bols are instances of that class:
+
+```py path=a.py
+reveal_type(True.__and__)  # revealed: @Todo(instance attributes)
+reveal_type(False.__or__)  # revealed: @Todo(instance attributes)
+```
+
+Some attributes are special-cased, however:
+
+```py path=b.py
+reveal_type(True.numerator)  # revealed: Literal[1]
+reveal_type(False.real)  # revealed: Literal[0]
+```
+
+### Bytes-literal attributes
+
+All attribute access on literal `bytes` types is currently delegated to `buitins.bytes`:
+
+```py
+reveal_type(b"foo".join)  # revealed: @Todo(instance attributes)
+reveal_type(b"foo".endswith)  # revealed: @Todo(instance attributes)
+```
+
+## References
+
+Some of the tests in the *Class and instance variables* section draw inspiration from
+[pyright's documentation] on this topic.
+
+[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
--- a/crates/red_knot_python_semantic/resources/mdtest/binary/booleans.md
+++ b/crates/red_knot_python_semantic/resources/mdtest/binary/booleans.md
@@ -50,44 +50,46 @@ reveal_type(b | b)  # revealed: Literal[False]
 ## Arithmetic with a variable

 ```py
-def _(a: bool):
-    def lhs_is_int(x: int):
-        reveal_type(x + a)  # revealed: int
-        reveal_type(x - a)  # revealed: int
-        reveal_type(x * a)  # revealed: int
-        reveal_type(x // a)  # revealed: int
-        reveal_type(x / a)  # revealed: int | float
-        reveal_type(x % a)  # revealed: int
+a = True
+b = False

-    def rhs_is_int(x: int):
-        reveal_type(a + x)  # revealed: int
-        reveal_type(a - x)  # revealed: int
-        reveal_type(a * x)  # revealed: int
-        reveal_type(a // x)  # revealed: int
-        reveal_type(a / x)  # revealed: int | float
-        reveal_type(a % x)  # revealed: int
+def lhs_is_int(x: int):
+    reveal_type(x + a)  # revealed: int
+    reveal_type(x - a)  # revealed: int
+    reveal_type(x * a)  # revealed: int
+    reveal_type(x // a)  # revealed: int
+    reveal_type(x / a)  # revealed: float
+    reveal_type(x % a)  # revealed: int

-    def lhs_is_bool(x: bool):
-        reveal_type(x + a)  # revealed: int
-        reveal_type(x - a)  # revealed: int
-        reveal_type(x * a)  # revealed: int
-        reveal_type(x // a)  # revealed: int
-        reveal_type(x / a)  # revealed: int | float
-        reveal_type(x % a)  # revealed: int
+def rhs_is_int(x: int):
+    reveal_type(a + x)  # revealed: int
+    reveal_type(a - x)  # revealed: int
+    reveal_type(a * x)  # revealed: int
+    reveal_type(a // x)  # revealed: int
+    reveal_type(a / x)  # revealed: float
+    reveal_type(a % x)  # revealed: int

-    def rhs_is_bool(x: bool):
-        reveal_type(a + x)  # revealed: int
-        reveal_type(a - x)  # revealed: int
-        reveal_type(a * x)  # revealed: int
-        reveal_type(a // x)  # revealed: int
-        reveal_type(a / x)  # revealed: int | float
-        reveal_type(a % x)  # revealed: int
+def lhs_is_bool(x: bool):
+    reveal_type(x + a)  # revealed: int
+    reveal_type(x - a)  # revealed: int
+    reveal_type(x * a)  # revealed: int
+    reveal_type(x // a)  # revealed: int
+    reveal_type(x / a)  # revealed: float
+    reveal_type(x % a)  # revealed: int

-    def both_are_bool(x: bool, y: bool):
-        reveal_type(x + y)  # revealed: int
-        reveal_type(x - y)  # revealed: int
-        reveal_type(x * y)  # revealed: int
-        reveal_type(x // y)  # revealed: int
-        reveal_type(x / y)  # revealed: int | float
-        reveal_type(x % y)  # revealed: int
+def rhs_is_bool(x: bool):
+    reveal_type(a + x)  # revealed: int
+    reveal_type(a - x)  # revealed: int
+    reveal_type(a * x)  # revealed: int
+    reveal_type(a // x)  # revealed: int
+    reveal_type(a / x)  # revealed: float
+    reveal_type(a % x)  # revealed: int
+
+def both_are_bool(x: bool, y: bool):
+    reveal_type(x + y)  # revealed: int
+    reveal_type(x - y)  # revealed: int
+    reveal_type(x * y)  # revealed: int
+    reveal_type(x // y)  # revealed: int
+    reveal_type(x / y)  # revealed: float
+    reveal_type(x % y)  # revealed: int
 ```
--- a/crates/red_knot_python_semantic/resources/mdtest/binary/classes.md
+++ b/crates/red_knot_python_semantic/resources/mdtest/binary/classes.md
@@ -22,6 +22,6 @@ reveal_type(A | B)  # revealed: UnionType
 class A: ...
 class B: ...

-# error: "Operator `|` is unsupported between objects of type `<class 'A'>` and `<class 'B'>`"
+# error: "Operator `|` is unsupported between objects of type `Literal[A]` and `Literal[B]`"
 reveal_type(A | B)  # revealed: Unknown
 ```
--- a/crates/red_knot_python_semantic/resources/mdtest/binary/custom.md
+++ b/crates/red_knot_python_semantic/resources/mdtest/binary/custom.md
@@ -3,8 +3,6 @@
 ## Class instances

 ```py
-from typing import Literal
-
 class Yes:
    def __add__(self, other) -> Literal["+"]:
        return "+"
@@ -138,8 +136,6 @@ reveal_type(No() // Yes())  # revealed: Unknown
 ## Subclass reflections override superclass dunders

 ```py
-from typing import Literal
-
 class Yes:
    def __add__(self, other) -> Literal["+"]:
        return "+"
@@ -298,8 +294,6 @@ itself. (For these operators to work on the class itself, they would have to be
 class's type, i.e. `type`.)

 ```py
-from typing import Literal
-
 class Yes:
    def __add__(self, other) -> Literal["+"]:
        return "+"
@@ -307,19 +301,17 @@ class Yes:
 class Sub(Yes): ...
 class No: ...

-# error: [unsupported-operator] "Operator `+` is unsupported between objects of type `<class 'Yes'>` and `<class 'Yes'>`"
+# error: [unsupported-operator] "Operator `+` is unsupported between objects of type `Literal[Yes]` and `Literal[Yes]`"
 reveal_type(Yes + Yes)  # revealed: Unknown
-# error: [unsupported-operator] "Operator `+` is unsupported between objects of type `<class 'Sub'>` and `<class 'Sub'>`"
+# error: [unsupported-operator] "Operator `+` is unsupported between objects of type `Literal[Sub]` and `Literal[Sub]`"
 reveal_type(Sub + Sub)  # revealed: Unknown
-# error: [unsupported-operator] "Operator `+` is unsupported between objects of type `<class 'No'>` and `<class 'No'>`"
+# error: [unsupported-operator] "Operator `+` is unsupported between objects of type `Literal[No]` and `Literal[No]`"
 reveal_type(No + No)  # revealed: Unknown
 ```

 ## Subclass

 ```py
-from typing import Literal
-
 class Yes:
    def __add__(self, other) -> Literal["+"]:
        return "+"
@@ -350,30 +342,30 @@ reveal_type(no() + no())  # revealed: Unknown
 def f():
    pass

-# error: [unsupported-operator] "Operator `+` is unsupported between objects of type `def f() -> Unknown` and `def f() -> Unknown`"
+# error: [unsupported-operator] "Operator `+` is unsupported between objects of type `Literal[f]` and `Literal[f]`"
 reveal_type(f + f)  # revealed: Unknown
-# error: [unsupported-operator] "Operator `-` is unsupported between objects of type `def f() -> Unknown` and `def f() -> Unknown`"
+# error: [unsupported-operator] "Operator `-` is unsupported between objects of type `Literal[f]` and `Literal[f]`"
 reveal_type(f - f)  # revealed: Unknown
-# error: [unsupported-operator] "Operator `*` is unsupported between objects of type `def f() -> Unknown` and `def f() -> Unknown`"
+# error: [unsupported-operator] "Operator `*` is unsupported between objects of type `Literal[f]` and `Literal[f]`"
 reveal_type(f * f)  # revealed: Unknown
-# error: [unsupported-operator] "Operator `@` is unsupported between objects of type `def f() -> Unknown` and `def f() -> Unknown`"
+# error: [unsupported-operator] "Operator `@` is unsupported between objects of type `Literal[f]` and `Literal[f]`"
 reveal_type(f @ f)  # revealed: Unknown
-# error: [unsupported-operator] "Operator `/` is unsupported between objects of type `def f() -> Unknown` and `def f() -> Unknown`"
+# error: [unsupported-operator] "Operator `/` is unsupported between objects of type `Literal[f]` and `Literal[f]`"
 reveal_type(f / f)  # revealed: Unknown
-# error: [unsupported-operator] "Operator `%` is unsupported between objects of type `def f() -> Unknown` and `def f() -> Unknown`"
+# error: [unsupported-operator] "Operator `%` is unsupported between objects of type `Literal[f]` and `Literal[f]`"
 reveal_type(f % f)  # revealed: Unknown
-# error: [unsupported-operator] "Operator `**` is unsupported between objects of type `def f() -> Unknown` and `def f() -> Unknown`"
+# error: [unsupported-operator] "Operator `**` is unsupported between objects of type `Literal[f]` and `Literal[f]`"
 reveal_type(f**f)  # revealed: Unknown
-# error: [unsupported-operator] "Operator `<<` is unsupported between objects of type `def f() -> Unknown` and `def f() -> Unknown`"
+# error: [unsupported-operator] "Operator `<<` is unsupported between objects of type `Literal[f]` and `Literal[f]`"
 reveal_type(f << f)  # revealed: Unknown
-# error: [unsupported-operator] "Operator `>>` is unsupported between objects of type `def f() -> Unknown` and `def f() -> Unknown`"
+# error: [unsupported-operator] "Operator `>>` is unsupported between objects of type `Literal[f]` and `Literal[f]`"
 reveal_type(f >> f)  # revealed: Unknown
-# error: [unsupported-operator] "Operator `|` is unsupported between objects of type `def f() -> Unknown` and `def f() -> Unknown`"
+# error: [unsupported-operator] "Operator `|` is unsupported between objects of type `Literal[f]` and `Literal[f]`"
 reveal_type(f | f)  # revealed: Unknown
-# error: [unsupported-operator] "Operator `^` is unsupported between objects of type `def f() -> Unknown` and `def f() -> Unknown`"
+# error: [unsupported-operator] "Operator `^` is unsupported between objects of type `Literal[f]` and `Literal[f]`"
 reveal_type(f ^ f)  # revealed: Unknown
-# error: [unsupported-operator] "Operator `&` is unsupported between objects of type `def f() -> Unknown` and `def f() -> Unknown`"
+# error: [unsupported-operator] "Operator `&` is unsupported between objects of type `Literal[f]` and `Literal[f]`"
 reveal_type(f & f)  # revealed: Unknown
-# error: [unsupported-operator] "Operator `//` is unsupported between objects of type `def f() -> Unknown` and `def f() -> Unknown`"
+# error: [unsupported-operator] "Operator `//` is unsupported between objects of type `Literal[f]` and `Literal[f]`"
 reveal_type(f // f)  # revealed: Unknown
 ```
--- a/crates/red_knot_python_semantic/resources/mdtest/binary/instances.md
+++ b/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
@@ -237,14 +237,17 @@ 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
+# TODO: this should be `B` (the return annotation of `B.__rsub__`),
+# because `A.__sub__` is annotated as only accepting `A`,
+# but `B.__rsub__` will accept `A`.
+reveal_type(A() - B())  # revealed: A
 ```

 ## Callable instances as dunders
@@ -259,38 +262,31 @@ 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
+reveal_type(B() + B())  # revealed: int
 ```

 ## Integration test: numbers from typeshed

-We get less precise results from binary operations on float/complex literals due to the special case
-for annotations of `float` or `complex`, which applies also to return annotations for typeshed
-dunder methods. Perhaps we could have a special-case on the special-case, to exclude these typeshed
-return annotations from the widening, and preserve a bit more precision here?
-
 ```py
-reveal_type(3j + 3.14)  # revealed: int | float | complex
-reveal_type(4.2 + 42)  # revealed: int | float
-reveal_type(3j + 3)  # revealed: int | float | complex
-reveal_type(3.14 + 3j)  # revealed: int | float | complex
-reveal_type(42 + 4.2)  # revealed: int | float
-reveal_type(3 + 3j)  # revealed: int | float | complex
+reveal_type(3j + 3.14)  # revealed: complex
+reveal_type(4.2 + 42)  # revealed: float
+reveal_type(3j + 3)  # revealed: complex
+
+# TODO should be complex, need to check arg type and fall back to `rhs.__radd__`
+reveal_type(3.14 + 3j)  # revealed: float
+
+# TODO should be float, need to check arg type and fall back to `rhs.__radd__`
+reveal_type(42 + 4.2)  # revealed: int
+
+# TODO should be complex, need to check arg type and fall back to `rhs.__radd__`
+reveal_type(3 + 3j)  # revealed: int

 def _(x: bool, y: int):
    reveal_type(x + y)  # revealed: int
-    reveal_type(4.2 + x)  # revealed: int | float
-    reveal_type(y + 4.12)  # revealed: int | float
+    reveal_type(4.2 + x)  # revealed: float
+
+    # TODO should be float, need to check arg type and fall back to `rhs.__radd__`
+    reveal_type(y + 4.12)  # revealed: int
 ```

 ## With literal types
@@ -300,17 +296,20 @@ 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
-reveal_type(1 + A())  # revealed: A
+# TODO should be `A` since `int.__add__` doesn't support `A` instances
+reveal_type(1 + A())  # revealed: int

 reveal_type(A() + "foo")  # revealed: A
-reveal_type("foo" + A())  # revealed: A
+# TODO should be `A` since `str.__add__` doesn't support `A` instances
+# TODO overloads
+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
@@ -318,14 +317,16 @@ 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(full tuple[...] support)
+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`:
 reveal_type(literal_string_instance)  # revealed: LiteralString

 reveal_type(A() + literal_string_instance)  # revealed: A
-reveal_type(literal_string_instance + A())  # 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)
 ```

 ## Operations involving instances of classes inheriting from `Any`
@@ -353,53 +354,6 @@ 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 `<class 'A'>` and `<class '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 `<class 'A'>` and `<class 'B'>`"
-reveal_type(A <= B)  # revealed: Unknown
-
-reveal_type(A[0])  # revealed: str
-```
-
 ## Unsupported

 ### Dunder as instance attribute
@@ -435,12 +389,10 @@ 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: ...

@@ -462,7 +414,7 @@ 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]
--- a/crates/red_knot_python_semantic/resources/mdtest/binary/integers.md
+++ b/crates/red_knot_python_semantic/resources/mdtest/binary/integers.md
@@ -10,15 +10,16 @@ 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"]`"
-reveal_type(2 + "f")  # revealed: Unknown
+# TODO: We don't currently verify that the actual parameter to int.__add__ matches the declared
+# formal parameter type.
+reveal_type(2 + "f")  # revealed: int

 def lhs(x: int):
    reveal_type(x + 1)  # revealed: int
    reveal_type(x - 4)  # revealed: int
    reveal_type(x * -1)  # revealed: int
    reveal_type(x // 3)  # revealed: int
-    reveal_type(x / 3)  # revealed: int | float
+    reveal_type(x / 3)  # revealed: float
    reveal_type(x % 3)  # revealed: int

 def rhs(x: int):
@@ -26,7 +27,7 @@ def rhs(x: int):
    reveal_type(3 - x)  # revealed: int
    reveal_type(3 * x)  # revealed: int
    reveal_type(-3 // x)  # revealed: int
-    reveal_type(-3 / x)  # revealed: int | float
+    reveal_type(-3 / x)  # revealed: float
    reveal_type(5 % x)  # revealed: int

 def both(x: int):
@@ -34,7 +35,7 @@ def both(x: int):
    reveal_type(x - x)  # revealed: int
    reveal_type(x * x)  # revealed: int
    reveal_type(x // x)  # revealed: int
-    reveal_type(x / x)  # revealed: int | float
+    reveal_type(x / x)  # revealed: float
    reveal_type(x % x)  # revealed: int
 ```

@@ -50,23 +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: int
-    # TODO: should be `Any` (overload 5 on `__pow__`), requires correct overload matching
-    reveal_type(2**x)  # revealed: int
-    # TODO: should be `Any` (overload 5 on `__pow__`), requires correct overload matching
-    reveal_type(x**x)  # revealed: int
-```
-
-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
@@ -93,20 +80,24 @@ c = 3 % 0  # error: "Cannot reduce object of type `Literal[3]` modulo zero"
 reveal_type(c)  # revealed: int

 # error: "Cannot divide object of type `int` by zero"
-reveal_type(int() / 0)  # revealed: int | float
+# revealed: float
+reveal_type(int() / 0)

 # error: "Cannot divide object of type `Literal[1]` by zero"
-reveal_type(1 / False)  # revealed: float
+# revealed: float
+reveal_type(1 / False)
 # error: [division-by-zero] "Cannot divide object of type `Literal[True]` by zero"
 True / False
 # error: [division-by-zero] "Cannot divide object of type `Literal[True]` by zero"
 bool(1) / False

 # error: "Cannot divide object of type `float` by zero"
-reveal_type(1.0 / 0)  # revealed: int | float
+# revealed: float
+reveal_type(1.0 / 0)

 class MyInt(int): ...

 # No error for a subclass of int
-reveal_type(MyInt(3) / 0)  # revealed: int | float
+# revealed: float
+reveal_type(MyInt(3) / 0)
 ```
--- a/crates/red_knot_python_semantic/resources/mdtest/boolean/short_circuit.md
+++ b/crates/red_knot_python_semantic/resources/mdtest/boolean/short_circuit.md
@@ -43,7 +43,7 @@ if True and (x := 1):

 ```py
 def _(flag: bool):
-    flag or (x := 1) or reveal_type(x)  # revealed: Never
+    flag or (x := 1) or reveal_type(x)  # revealed: Literal[1]

    # error: [unresolved-reference]
    flag or reveal_type(y) or (y := 1)  # revealed: Unknown
--- a/crates/red_knot_python_semantic/resources/mdtest/boundness_declaredness/public.md
+++ b/crates/red_knot_python_semantic/resources/mdtest/boundness_declaredness/public.md
@@ -0,0 +1,209 @@
+# Boundness and declaredness: public uses
+
+This document demonstrates how type-inference and diagnostics works for *public* uses of a symbol,
+that is, a use of a symbol from another scope. If a symbol has a declared type in its local scope
+(e.g. `int`), we use that as the symbol's "public type" (the type of the symbol from the perspective
+of other scopes) even if there is a more precise local inferred type for the symbol (`Literal[1]`).
+
+We test the whole matrix of possible boundness and declaredness states. The current behavior is
+summarized in the following table, while the tests below demonstrate each case. Note that some of
+this behavior is questionable and might change in the future. See the TODOs in `symbol_by_id`
+(`types.rs`) and [this issue](https://github.com/astral-sh/ruff/issues/14297) for more information.
+In particular, we should raise errors in the "possibly-undeclared-and-unbound" as well as the
+"undeclared-and-possibly-unbound" cases (marked with a "?").
+
+| **Public type**  | declared     | possibly-undeclared        | undeclared   |
+| ---------------- | ------------ | -------------------------- | ------------ |
+| bound            | `T_declared` | `T_declared \| T_inferred` | `T_inferred` |
+| possibly-unbound | `T_declared` | `T_declared \| T_inferred` | `T_inferred` |
+| unbound          | `T_declared` | `T_declared`               | `Unknown`    |
+
+| **Diagnostic**   | declared | possibly-undeclared       | undeclared          |
+| ---------------- | -------- | ------------------------- | ------------------- |
+| bound            |          |                           |                     |
+| possibly-unbound |          | `possibly-unbound-import` | ?                   |
+| unbound          |          | ?                         | `unresolved-import` |
+
+## Declared
+
+### Declared and bound
+
+If a symbol has a declared type (`int`), we use that even if there is a more precise inferred type
+(`Literal[1]`), or a conflicting inferred type (`Literal[2]`):
+
+```py path=mod.py
+x: int = 1
+
+# error: [invalid-assignment]
+y: str = 2
+```
+
+```py
+from mod import x, y
+
+reveal_type(x)  # revealed: int
+reveal_type(y)  # revealed: str
+```
+
+### Declared and possibly unbound
+
+If a symbol is declared and *possibly* unbound, we trust that other module and use the declared type
+without raising an error.
+
+```py path=mod.py
+def flag() -> bool: ...
+
+x: int
+y: str
+if flag:
+    x = 1
+    # error: [invalid-assignment]
+    y = 2
+```
+
+```py
+from mod import x, y
+
+reveal_type(x)  # revealed: int
+reveal_type(y)  # revealed: str
+```
+
+### Declared and unbound
+
+Similarly, if a symbol is declared but unbound, we do not raise an error. We trust that this symbol
+is available somehow and simply use the declared type.
+
+```py path=mod.py
+x: int
+```
+
+```py
+from mod import x
+
+reveal_type(x)  # revealed: int
+```
+
+## Possibly undeclared
+
+### Possibly undeclared and bound
+
+If a symbol is possibly undeclared but definitely bound, we use the union of the declared and
+inferred types:
+
+```py path=mod.py
+from typing import Any
+
+def flag() -> bool: ...
+
+x = 1
+y = 2
+if flag():
+    x: Any
+    # error: [invalid-declaration]
+    y: str
+```
+
+```py
+from mod import x, y
+
+reveal_type(x)  # revealed: Literal[1] | Any
+reveal_type(y)  # revealed: Literal[2] | Unknown
+```
+
+### Possibly undeclared and possibly unbound
+
+If a symbol is possibly undeclared and possibly unbound, we also use the union of the declared and
+inferred types. This case is interesting because the "possibly declared" definition might not be the
+same as the "possibly bound" definition (symbol `y`). Note that we raise a `possibly-unbound-import`
+error for both `x` and `y`:
+
+```py path=mod.py
+def flag() -> bool: ...
+
+if flag():
+    x: Any = 1
+    y = 2
+else:
+    y: str
+```
+
+```py
+# error: [possibly-unbound-import]
+# error: [possibly-unbound-import]
+from mod import x, y
+
+reveal_type(x)  # revealed: Literal[1] | Any
+reveal_type(y)  # revealed: Literal[2] | str
+```
+
+### Possibly undeclared and unbound
+
+If a symbol is possibly undeclared and definitely unbound, we currently do not raise an error. This
+seems inconsistent when compared to the case just above.
+
+```py path=mod.py
+def flag() -> bool: ...
+
+if flag():
+    x: int
+```
+
+```py
+# TODO: this should raise an error. Once we fix this, update the section description and the table
+# on top of this document.
+from mod import x
+
+reveal_type(x)  # revealed: int
+```
+
+## Undeclared
+
+### Undeclared but bound
+
+We use the inferred type as the public type, if a symbol has no declared type.
+
+```py path=mod.py
+x = 1
+```
+
+```py
+from mod import x
+
+reveal_type(x)  # revealed: Literal[1]
+```
+
+### Undeclared and possibly unbound
+
+If a symbol is undeclared and *possibly* unbound, we currently do not raise an error. This seems
+inconsistent when compared to the "possibly-undeclared-and-possibly-unbound" case.
+
+```py path=mod.py
+def flag() -> bool: ...
+
+if flag:
+    x = 1
+```
+
+```py
+# TODO: this should raise an error. Once we fix this, update the section description and the table
+# on top of this document.
+from mod import x
+
+reveal_type(x)  # revealed: Literal[1]
+```
+
+### Undeclared and unbound
+
+If a symbol is undeclared *and* unbound, we infer `Unknown` and raise an error.
+
+```py path=mod.py
+if False:
+    x: int = 1
+```
+
+```py
+# error: [unresolved-import]
+from mod import x
+
+reveal_type(x)  # revealed: Unknown
+```
--- a/crates/red_knot_python_semantic/resources/mdtest/call/callable_instance.md
+++ b/crates/red_knot_python_semantic/resources/mdtest/call/callable_instance.md
@@ -4,14 +4,14 @@

 ```py
 class Multiplier:
-    def __init__(self, factor: int):
+    def __init__(self, factor: float):
        self.factor = factor

-    def __call__(self, number: int) -> int:
+    def __call__(self, number: float) -> float:
        return number * self.factor

-a = Multiplier(2)(3)
-reveal_type(a)  # revealed: int
+a = Multiplier(2.0)(3.0)
+reveal_type(a)  # revealed: float

 class Unit: ...

@@ -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()
@@ -54,7 +52,7 @@ class NonCallable:
    __call__ = 1

 a = NonCallable()
-# error: [call-non-callable] "Object of type `Literal[1]` is not callable"
+# error: "Object of type `NonCallable` is not callable"
 reveal_type(a())  # revealed: Unknown
 ```

@@ -66,11 +64,10 @@ 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"
+    # error: "Object of type `Literal[1] | Literal[__call__]` is not callable (due to union element `Literal[1]`)"
    reveal_type(a())  # revealed: Unknown | int
 ```

@@ -85,7 +82,7 @@ class C:

 c = C()

-# error: 15 [invalid-argument-type] "Argument to this function is incorrect: Expected `int`, found `Literal["foo"]`"
+# 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
 ```

@@ -99,29 +96,6 @@ class C:

 c = C()

-# error: 13 [invalid-argument-type] "Argument to this function is incorrect: Expected `int`, found `C`"
+# 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
 ```
-
-## Union over callables
-
-### Possibly unbound `__call__`
-
-```py
-def outer(cond1: bool):
-    class Test:
-        if cond1:
-            def __call__(self): ...
-
-    class Other:
-        def __call__(self): ...
-
-    def inner(cond2: bool):
-        if cond2:
-            a = Test()
-        else:
-            a = Other()
-
-            # error: [call-non-callable] "Object of type `Test` is not callable (possibly unbound `__call__` method)"
-        a()
-```
--- a/crates/red_knot_python_semantic/resources/mdtest/call/constructor.md
+++ b/crates/red_knot_python_semantic/resources/mdtest/call/constructor.md
@@ -0,0 +1,7 @@
+# Constructor
+
+```py
+class Foo: ...
+
+reveal_type(Foo())  # revealed: Foo
+```
--- a/crates/red_knot_python_semantic/resources/mdtest/call/function.md
+++ b/crates/red_knot_python_semantic/resources/mdtest/call/function.md
@@ -21,11 +21,6 @@ reveal_type(get_int_async())  # revealed: @Todo(generic types.CoroutineType)

 ## Generic

-```toml
-[environment]
-python-version = "3.12"
-```
-
 ```py
 def get_int[T]() -> int:
    return 42
@@ -48,7 +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
@@ -77,7 +73,7 @@ def _(flag: bool):
 def f(x: int) -> int:
    return 1

-# error: 15 [invalid-argument-type] "Argument to this function is incorrect: Expected `int`, found `Literal["foo"]`"
+# error: 15 [invalid-argument-type] "Object of type `Literal["foo"]` cannot be assigned to parameter 1 (`x`) of function `f`; expected type `int`"
 reveal_type(f("foo"))  # revealed: int
 ```

@@ -87,7 +83,7 @@ reveal_type(f("foo"))  # revealed: int
 def f(x: int, /) -> int:
    return 1

-# error: 15 [invalid-argument-type] "Argument to this function is incorrect: Expected `int`, found `Literal["foo"]`"
+# error: 15 [invalid-argument-type] "Object of type `Literal["foo"]` cannot be assigned to parameter 1 (`x`) of function `f`; expected type `int`"
 reveal_type(f("foo"))  # revealed: int
 ```

@@ -97,7 +93,7 @@ reveal_type(f("foo"))  # revealed: int
 def f(*args: int) -> int:
    return 1

-# error: 15 [invalid-argument-type] "Argument to this function is incorrect: Expected `int`, found `Literal["foo"]`"
+# error: 15 [invalid-argument-type] "Object of type `Literal["foo"]` cannot be assigned to parameter `*args` of function `f`; expected type `int`"
 reveal_type(f("foo"))  # revealed: int
 ```

@@ -107,7 +103,7 @@ reveal_type(f("foo"))  # revealed: int
 def f(x: int) -> int:
    return 1

-# error: 15 [invalid-argument-type] "Argument to this function is incorrect: Expected `int`, found `Literal["foo"]`"
+# error: 15 [invalid-argument-type] "Object of type `Literal["foo"]` cannot be assigned to parameter `x` of function `f`; expected type `int`"
 reveal_type(f(x="foo"))  # revealed: int
 ```

@@ -117,7 +113,7 @@ reveal_type(f(x="foo"))  # revealed: int
 def f(*, x: int) -> int:
    return 1

-# error: 15 [invalid-argument-type] "Argument to this function is incorrect: Expected `int`, found `Literal["foo"]`"
+# error: 15 [invalid-argument-type] "Object of type `Literal["foo"]` cannot be assigned to parameter `x` of function `f`; expected type `int`"
 reveal_type(f(x="foo"))  # revealed: int
 ```

@@ -127,7 +123,7 @@ reveal_type(f(x="foo"))  # revealed: int
 def f(**kwargs: int) -> int:
    return 1

-# error: 15 [invalid-argument-type] "Argument to this function is incorrect: Expected `int`, found `Literal["foo"]`"
+# error: 15 [invalid-argument-type] "Object of type `Literal["foo"]` cannot be assigned to parameter `**kwargs` of function `f`; expected type `int`"
 reveal_type(f(x="foo"))  # revealed: int
 ```

@@ -137,8 +133,8 @@ reveal_type(f(x="foo"))  # revealed: int
 def f(x: int = 1, y: str = "foo") -> int:
    return 1

-# error: 15 [invalid-argument-type] "Argument to this function is incorrect: Expected `str`, found `Literal[2]`"
-# error: 20 [invalid-argument-type] "Argument to this function is incorrect: Expected `int`, found `Literal["bar"]`"
+# error: 15 [invalid-argument-type] "Object of type `Literal[2]` cannot be assigned to parameter `y` of function `f`; expected type `str`"
+# error: 20 [invalid-argument-type] "Object of type `Literal["bar"]` cannot be assigned to parameter `x` of function `f`; expected type `int`"
 reveal_type(f(y=2, x="bar"))  # revealed: int
 ```

@@ -282,18 +278,19 @@ proper diagnostics in case of missing or superfluous arguments.
 from typing_extensions import reveal_type

 # error: [missing-argument] "No argument provided for required parameter `obj` of function `reveal_type`"
-reveal_type()
+reveal_type()  # revealed: Unknown

 # error: [too-many-positional-arguments] "Too many positional arguments to function `reveal_type`: expected 1, got 2"
-reveal_type(1, 2)
+reveal_type(1, 2)  # revealed: Literal[1]
 ```

 ### `static_assert`

 ```py
-from ty_extensions import static_assert
+from knot_extensions import static_assert

 # error: [missing-argument] "No argument provided for required parameter `condition` of function `static_assert`"
+# error: [static-assert-error]
 static_assert()

 # error: [too-many-positional-arguments] "Too many positional arguments to function `static_assert`: expected 2, got 3"
@@ -313,7 +310,7 @@ len([], 1)
 ### Type API predicates

 ```py
-from ty_extensions import is_subtype_of, is_fully_static
+from knot_extensions import is_subtype_of, is_fully_static

 # error: [missing-argument]
 is_subtype_of()
--- a/crates/red_knot_python_semantic/resources/mdtest/call/invalid_syntax.md
+++ b/crates/red_knot_python_semantic/resources/mdtest/call/invalid_syntax.md
@@ -24,7 +24,7 @@ to the valid order:
 def f(**kw: int, x: str) -> int:
    return 1

-# error: 15 [invalid-argument-type] "Argument to this function is incorrect: Expected `str`, found `Literal[1]`"
+# error: 15 [invalid-argument-type] "Object of type `Literal[1]` cannot be assigned to parameter 1 (`x`) of function `f`; expected type `str`"
 reveal_type(f(1))  # revealed: int
 ```

@@ -38,7 +38,7 @@ def f(x: int = 1, y: str) -> int:
    return 1

 reveal_type(f(y="foo"))  # revealed: int
-# error: [invalid-argument-type] "Argument to this function is incorrect: Expected `int`, found `Literal["foo"]`"
+# error: [invalid-argument-type] "Object of type `Literal["foo"]` cannot be assigned to parameter 1 (`x`) of function `f`; expected type `int`"
 # error: [missing-argument] "No argument provided for required parameter `y` of function `f`"
 reveal_type(f("foo"))  # revealed: int
 ```
--- a/crates/red_knot_python_semantic/resources/mdtest/call/union.md
+++ b/crates/red_knot_python_semantic/resources/mdtest/call/union.md
@@ -0,0 +1,77 @@
+# Unions in calls
+
+## Union of return types
+
+```py
+def _(flag: bool):
+    if flag:
+        def f() -> int:
+            return 1
+    else:
+        def f() -> str:
+            return "foo"
+    reveal_type(f())  # revealed: int | str
+```
+
+## Calling with an unknown union
+
+```py
+from nonexistent import f  # error: [unresolved-import] "Cannot resolve import `nonexistent`"
+
+def coinflip() -> bool:
+    return True
+
+if coinflip():
+    def f() -> int:
+        return 1
+
+reveal_type(f())  # revealed: Unknown | int
+```
+
+## Non-callable elements in a union
+
+Calling a union with a non-callable element should emit a diagnostic.
+
+```py
+def _(flag: bool):
+    if flag:
+        f = 1
+    else:
+        def f() -> int:
+            return 1
+    x = f()  # error: "Object of type `Literal[1] | Literal[f]` is not callable (due to union element `Literal[1]`)"
+    reveal_type(x)  # revealed: Unknown | int
+```
+
+## Multiple non-callable elements in a union
+
+Calling a union with multiple non-callable elements should mention all of them in the diagnostic.
+
+```py
+def _(flag: bool, flag2: bool):
+    if flag:
+        f = 1
+    elif flag2:
+        f = "foo"
+    else:
+        def f() -> int:
+            return 1
+    # error: "Object of type `Literal[1, "foo"] | Literal[f]` is not callable (due to union elements Literal[1], Literal["foo"])"
+    # revealed: Unknown | int
+    reveal_type(f())
+```
+
+## All non-callable union elements
+
+Calling a union with no callable elements can emit a simpler diagnostic.
+
+```py
+def _(flag: bool):
+    if flag:
+        f = 1
+    else:
+        f = "foo"
+
+    x = f()  # error: "Object of type `Literal[1, "foo"]` is not callable"
+    reveal_type(x)  # revealed: Unknown
+```
--- a/crates/red_knot_python_semantic/resources/mdtest/comparison/byte_literals.md
+++ b/crates/red_knot_python_semantic/resources/mdtest/comparison/byte_literals.md
--- a/crates/red_knot_python_semantic/resources/mdtest/comparison/identity.md
+++ b/crates/red_knot_python_semantic/resources/mdtest/comparison/identity.md
--- a/crates/red_knot_python_semantic/resources/mdtest/comparison/instances/membership_test.md
+++ b/crates/red_knot_python_semantic/resources/mdtest/comparison/instances/membership_test.md
@@ -21,9 +21,8 @@ class A:

 reveal_type("hello" in A())  # revealed: bool
 reveal_type("hello" not in A())  # revealed: bool
-# error: [unsupported-operator] "Operator `in` is not supported for types `int` and `A`, in comparing `Literal[42]` with `A`"
+# TODO: should emit diagnostic, need to check arg type, will fail
 reveal_type(42 in A())  # revealed: bool
-# error: [unsupported-operator] "Operator `not in` is not supported for types `int` and `A`, in comparing `Literal[42]` with `A`"
 reveal_type(42 not in A())  # revealed: bool
 ```

@@ -127,9 +126,9 @@ class A:

 reveal_type(CheckContains() in A())  # revealed: bool

-# error: [unsupported-operator] "Operator `in` is not supported for types `CheckIter` and `A`"
+# TODO: should emit diagnostic, need to check arg type,
+# should not fall back to __iter__ or __getitem__
 reveal_type(CheckIter() in A())  # revealed: bool
-# error: [unsupported-operator] "Operator `in` is not supported for types `CheckGetItem` and `A`"
 reveal_type(CheckGetItem() in A())  # revealed: bool

 class B:
@@ -155,50 +154,7 @@ class A:
    def __getitem__(self, key: str) -> str:
        return "foo"

-# error: [unsupported-operator] "Operator `in` is not supported for types `int` and `A`, in comparing `Literal[42]` with `A`"
+# TODO should emit a diagnostic
 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()
-```
--- a/crates/red_knot_python_semantic/resources/mdtest/comparison/instances/rich_comparison.md
+++ b/crates/red_knot_python_semantic/resources/mdtest/comparison/instances/rich_comparison.md
@@ -0,0 +1,320 @@
+# Comparison: Rich Comparison
+
+Rich comparison operations (`==`, `!=`, `<`, `<=`, `>`, `>=`) in Python are implemented through
+double-underscore methods that allow customization of comparison behavior.
+
+For references, see:
+
+- <https://docs.python.org/3/reference/datamodel.html#object.__lt__>
+- <https://snarky.ca/unravelling-rich-comparison-operators/>
+
+## Rich Comparison Dunder Implementations For Same Class
+
+Classes can support rich comparison by implementing dunder methods like `__eq__`, `__ne__`, etc. The
+most common case involves implementing these methods for the same type:
+
+```py
+from __future__ import annotations
+
+class A:
+    def __eq__(self, other: A) -> int:
+        return 42
+
+    def __ne__(self, other: A) -> float:
+        return 42.0
+
+    def __lt__(self, other: A) -> str:
+        return "42"
+
+    def __le__(self, other: A) -> bytes:
+        return b"42"
+
+    def __gt__(self, other: A) -> list:
+        return [42]
+
+    def __ge__(self, other: A) -> set:
+        return {42}
+
+reveal_type(A() == A())  # revealed: int
+reveal_type(A() != A())  # revealed: float
+reveal_type(A() < A())  # revealed: str
+reveal_type(A() <= A())  # revealed: bytes
+reveal_type(A() > A())  # revealed: list
+reveal_type(A() >= A())  # revealed: set
+```
+
+## Rich Comparison Dunder Implementations for Other Class
+
+In some cases, classes may implement rich comparison dunder methods for comparisons with a different
+type:
+
+```py
+from __future__ import annotations
+
+class A:
+    def __eq__(self, other: B) -> int:
+        return 42
+
+    def __ne__(self, other: B) -> float:
+        return 42.0
+
+    def __lt__(self, other: B) -> str:
+        return "42"
+
+    def __le__(self, other: B) -> bytes:
+        return b"42"
+
+    def __gt__(self, other: B) -> list:
+        return [42]
+
+    def __ge__(self, other: B) -> set:
+        return {42}
+
+class B: ...
+
+reveal_type(A() == B())  # revealed: int
+reveal_type(A() != B())  # revealed: float
+reveal_type(A() < B())  # revealed: str
+reveal_type(A() <= B())  # revealed: bytes
+reveal_type(A() > B())  # revealed: list
+reveal_type(A() >= B())  # revealed: set
+```
+
+## Reflected Comparisons
+
+Fallback to the right-hand side’s comparison methods occurs when the left-hand side does not define
+them. Note: class `B` has its own `__eq__` and `__ne__` methods to override those of `object`, but
+these methods will be ignored here because they require a mismatched operand type.
+
+```py
+from __future__ import annotations
+
+class A:
+    def __eq__(self, other: B) -> int:
+        return 42
+
+    def __ne__(self, other: B) -> float:
+        return 42.0
+
+    def __lt__(self, other: B) -> str:
+        return "42"
+
+    def __le__(self, other: B) -> bytes:
+        return b"42"
+
+    def __gt__(self, other: B) -> list:
+        return [42]
+
+    def __ge__(self, other: B) -> set:
+        return {42}
+
+class B:
+    # To override builtins.object.__eq__ and builtins.object.__ne__
+    # TODO these should emit an invalid override diagnostic
+    def __eq__(self, other: str) -> B:
+        return B()
+
+    def __ne__(self, other: str) -> B:
+        return B()
+
+# TODO: should be `int` and `float`.
+# Need to check arg type and fall back to `rhs.__eq__` and `rhs.__ne__`.
+#
+# Because `object.__eq__` and `object.__ne__` accept `object` in typeshed,
+# this can only happen with an invalid override of these methods,
+# but we still support it.
+reveal_type(B() == A())  # revealed: B
+reveal_type(B() != A())  # revealed: B
+
+reveal_type(B() < A())  # revealed: list
+reveal_type(B() <= A())  # revealed: set
+
+reveal_type(B() > A())  # revealed: str
+reveal_type(B() >= A())  # revealed: bytes
+
+class C:
+    def __gt__(self, other: C) -> int:
+        return 42
+
+    def __ge__(self, other: C) -> float:
+        return 42.0
+
+reveal_type(C() < C())  # revealed: int
+reveal_type(C() <= C())  # revealed: float
+```
+
+## Reflected Comparisons with Subclasses
+
+When subclasses override comparison methods, these overridden methods take precedence over those in
+the parent class. Class `B` inherits from `A` and redefines comparison methods to return types other
+than `A`.
+
+```py
+from __future__ import annotations
+
+class A:
+    def __eq__(self, other: A) -> A:
+        return A()
+
+    def __ne__(self, other: A) -> A:
+        return A()
+
+    def __lt__(self, other: A) -> A:
+        return A()
+
+    def __le__(self, other: A) -> A:
+        return A()
+
+    def __gt__(self, other: A) -> A:
+        return A()
+
+    def __ge__(self, other: A) -> A:
+        return A()
+
+class B(A):
+    def __eq__(self, other: A) -> int:
+        return 42
+
+    def __ne__(self, other: A) -> float:
+        return 42.0
+
+    def __lt__(self, other: A) -> str:
+        return "42"
+
+    def __le__(self, other: A) -> bytes:
+        return b"42"
+
+    def __gt__(self, other: A) -> list:
+        return [42]
+
+    def __ge__(self, other: A) -> set:
+        return {42}
+
+reveal_type(A() == B())  # revealed: int
+reveal_type(A() != B())  # revealed: float
+
+reveal_type(A() < B())  # revealed: list
+reveal_type(A() <= B())  # revealed: set
+
+reveal_type(A() > B())  # revealed: str
+reveal_type(A() >= B())  # revealed: bytes
+```
+
+## Reflected Comparisons with Subclass But Falls Back to LHS
+
+In the case of a subclass, the right-hand side has priority. However, if the overridden dunder
+method has an mismatched type to operand, the comparison will fall back to the left-hand side.
+
+```py
+from __future__ import annotations
+
+class A:
+    def __lt__(self, other: A) -> A:
+        return A()
+
+    def __gt__(self, other: A) -> A:
+        return A()
+
+class B(A):
+    def __lt__(self, other: int) -> B:
+        return B()
+
+    def __gt__(self, other: int) -> B:
+        return B()
+
+# TODO: should be `A`, need to check argument type and fall back to LHS method
+reveal_type(A() < B())  # revealed: B
+reveal_type(A() > B())  # revealed: B
+```
+
+## Operations involving instances of classes inheriting from `Any`
+
+`Any` and `Unknown` represent a set of possible runtime objects, wherein the bounds of the set are
+unknown. Whether the left-hand operand's dunder or the right-hand operand's reflected dunder depends
+on whether the right-hand operand is an instance of a class that is a subclass of the left-hand
+operand's class and overrides the reflected dunder. In the following example, because of the
+unknowable nature of `Any`/`Unknown`, we must consider both possibilities: `Any`/`Unknown` might
+resolve to an unknown third class that inherits from `X` and overrides `__gt__`; but it also might
+not. Thus, the correct answer here for the `reveal_type` is `int | Unknown`.
+
+(This test is referenced from `mdtest/binary/instances.md`)
+
+```py
+from does_not_exist import Foo  # error: [unresolved-import]
+
+reveal_type(Foo)  # revealed: Unknown
+
+class X:
+    def __lt__(self, other: object) -> int:
+        return 42
+
+class Y(Foo): ...
+
+# TODO: Should be `int | Unknown`; see above discussion.
+reveal_type(X() < Y())  # revealed: int
+```
+
+## Equality and Inequality Fallback
+
+This test confirms that `==` and `!=` comparisons default to identity comparisons (`is`, `is not`)
+when argument types do not match the method signature.
+
+Please refer to the [docs](https://docs.python.org/3/reference/datamodel.html#object.__eq__)
+
+```py
+from __future__ import annotations
+
+class A:
+    # TODO both these overrides should emit invalid-override diagnostic
+    def __eq__(self, other: int) -> A:
+        return A()
+
+    def __ne__(self, other: int) -> A:
+        return A()
+
+# TODO: it should be `bool`, need to check arg type and fall back to `is` and `is not`
+reveal_type(A() == A())  # revealed: A
+reveal_type(A() != A())  # revealed: A
+```
+
+## Object Comparisons with Typeshed
+
+```py
+class A: ...
+
+reveal_type(A() == object())  # revealed: bool
+reveal_type(A() != object())  # revealed: bool
+reveal_type(object() == A())  # revealed: bool
+reveal_type(object() != A())  # revealed: bool
+
+# error: [unsupported-operator] "Operator `<` is not supported for types `A` and `object`"
+# revealed: Unknown
+reveal_type(A() < object())
+```
+
+## Numbers Comparison with typeshed
+
+```py
+reveal_type(1 == 1.0)  # revealed: bool
+reveal_type(1 != 1.0)  # revealed: bool
+reveal_type(1 < 1.0)  # revealed: bool
+reveal_type(1 <= 1.0)  # revealed: bool
+reveal_type(1 > 1.0)  # revealed: bool
+reveal_type(1 >= 1.0)  # revealed: bool
+
+reveal_type(1 == 2j)  # revealed: bool
+reveal_type(1 != 2j)  # revealed: bool
+
+# TODO: should be Unknown and emit diagnostic,
+# need to check arg type and should be failed
+reveal_type(1 < 2j)  # revealed: bool
+reveal_type(1 <= 2j)  # revealed: bool
+reveal_type(1 > 2j)  # revealed: bool
+reveal_type(1 >= 2j)  # revealed: bool
+
+def f(x: bool, y: int):
+    reveal_type(x < y)  # revealed: bool
+    reveal_type(y < x)  # revealed: bool
+    reveal_type(4.2 < x)  # revealed: bool
+    reveal_type(x < 4.2)  # revealed: bool
+```
--- a/crates/red_knot_python_semantic/resources/mdtest/comparison/integers.md
+++ b/crates/red_knot_python_semantic/resources/mdtest/comparison/integers.md
@@ -12,8 +12,8 @@ reveal_type(1 is 1)  # revealed: bool
 reveal_type(1 is not 1)  # revealed: bool
 reveal_type(1 is 2)  # revealed: Literal[False]
 reveal_type(1 is not 7)  # revealed: Literal[True]
-# error: [unsupported-operator] "Operator `<=` is not supported for types `int` and `str`, in comparing `Literal[1]` with `Literal[""]`"
-reveal_type(1 <= "" and 0 < 1)  # revealed: (Unknown & ~AlwaysTruthy) | Literal[True]
+# TODO: should be Unknown, and emit diagnostic, once we check call argument types
+reveal_type(1 <= "" and 0 < 1)  # revealed: bool
 ```

 ## Integer instance
--- a/crates/red_knot_python_semantic/resources/mdtest/comparison/intersections.md
+++ b/crates/red_knot_python_semantic/resources/mdtest/comparison/intersections.md
@@ -6,11 +6,7 @@ If we have an intersection type `A & B` and we get a definitive true/false answe
 types, we can infer that the result for the intersection type is also true/false:

 ```py
-from typing import Literal
-
-class Base:
-    def __gt__(self, other) -> bool:
-        return False
+class Base: ...

 class Child1(Base):
    def __eq__(self, other) -> Literal[True]:
@@ -50,17 +46,13 @@ reveal_type(x)  # revealed: LiteralString
 if x != "abc":
    reveal_type(x)  # revealed: LiteralString & ~Literal["abc"]

-    # TODO: This should be `Literal[False]`
-    reveal_type(x == "abc")  # revealed: bool
-    # TODO: This should be `Literal[False]`
-    reveal_type("abc" == x)  # revealed: bool
+    reveal_type(x == "abc")  # revealed: Literal[False]
+    reveal_type("abc" == x)  # revealed: Literal[False]
    reveal_type(x == "something else")  # revealed: bool
    reveal_type("something else" == x)  # revealed: bool

-    # TODO: This should be `Literal[True]`
-    reveal_type(x != "abc")  # revealed: bool
-    # TODO: This should be `Literal[True]`
-    reveal_type("abc" != x)  # revealed: bool
+    reveal_type(x != "abc")  # revealed: Literal[True]
+    reveal_type("abc" != x)  # revealed: Literal[True]
    reveal_type(x != "something else")  # revealed: bool
    reveal_type("something else" != x)  # revealed: bool

@@ -83,10 +75,10 @@ def _(x: int):
    if x != 1:
        reveal_type(x)  # revealed: int & ~Literal[1]

-        reveal_type(x != 1)  # revealed: bool
+        reveal_type(x != 1)  # revealed: Literal[True]
        reveal_type(x != 2)  # revealed: bool

-        reveal_type(x == 1)  # revealed: bool
+        reveal_type(x == 1)  # revealed: Literal[False]
        reveal_type(x == 2)  # revealed: bool
 ```

@@ -114,8 +106,7 @@ given operator:

 ```py
 class Container:
-    def __contains__(self, x) -> bool:
-        return False
+    def __contains__(self, x) -> bool: ...

 class NonContainer: ...

@@ -135,8 +126,7 @@ unsupported for the given operator:

 ```py
 class Container:
-    def __contains__(self, x) -> bool:
-        return False
+    def __contains__(self, x) -> bool: ...

 class NonContainer: ...

--- a/crates/red_knot_python_semantic/resources/mdtest/comparison/non_bool_returns.md
+++ b/crates/red_knot_python_semantic/resources/mdtest/comparison/non_bool_returns.md
@@ -22,22 +22,16 @@ 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: ...

 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
+reveal_type(x)  # revealed: A & ~AlwaysTruthy | B

 y = 0 < 1 < A() < 3
 reveal_type(y)  # revealed: Literal[False] | A
--- a/crates/red_knot_python_semantic/resources/mdtest/comparison/strings.md
+++ b/crates/red_knot_python_semantic/resources/mdtest/comparison/strings.md
--- a/crates/red_knot_python_semantic/resources/mdtest/comparison/tuples.md
+++ b/crates/red_knot_python_semantic/resources/mdtest/comparison/tuples.md
@@ -33,7 +33,7 @@ reveal_type(a >= b)  # revealed: Literal[False]

 Even when tuples have different lengths, comparisons should be handled appropriately.

-```py
+```py path=different_length.py
 a = (1, 2, 3)
 b = (1, 2, 3, 4)

@@ -92,20 +92,17 @@ reveal_type(a == b)  # revealed: bool
 # TODO: should be Literal[True], once we implement (in)equality for mismatched literals
 reveal_type(a != b)  # revealed: bool

-# error: [unsupported-operator] "Operator `<` is not supported for types `int` and `str`, in comparing `tuple[Literal[1], Literal[2]]` with `tuple[Literal[1], Literal["hello"]]`"
-reveal_type(a < b)  # revealed: Unknown
-# error: [unsupported-operator] "Operator `<=` is not supported for types `int` and `str`, in comparing `tuple[Literal[1], Literal[2]]` with `tuple[Literal[1], Literal["hello"]]`"
-reveal_type(a <= b)  # revealed: Unknown
-# error: [unsupported-operator] "Operator `>` is not supported for types `int` and `str`, in comparing `tuple[Literal[1], Literal[2]]` with `tuple[Literal[1], Literal["hello"]]`"
-reveal_type(a > b)  # revealed: Unknown
-# error: [unsupported-operator] "Operator `>=` is not supported for types `int` and `str`, in comparing `tuple[Literal[1], Literal[2]]` with `tuple[Literal[1], Literal["hello"]]`"
-reveal_type(a >= b)  # revealed: Unknown
+# TODO: should be Unknown and add more informative diagnostics
+reveal_type(a < b)  # revealed: bool
+reveal_type(a <= b)  # revealed: bool
+reveal_type(a > b)  # revealed: bool
+reveal_type(a >= b)  # revealed: bool
 ```

 However, if the lexicographic comparison completes without reaching a point where str and int are
 compared, Python will still produce a result based on the prior elements.

-```py
+```py path=short_circuit.py
 a = (1, 2)
 b = (999999, "hello")

@@ -147,40 +144,33 @@ of the dunder methods.)
 ```py
 from __future__ import annotations

-class EqReturnType: ...
-class NeReturnType: ...
-class LtReturnType: ...
-class LeReturnType: ...
-class GtReturnType: ...
-class GeReturnType: ...
-
 class A:
-    def __eq__(self, o: object) -> EqReturnType:
-        return EqReturnType()
+    def __eq__(self, o: object) -> str:
+        return "hello"

-    def __ne__(self, o: object) -> NeReturnType:
-        return NeReturnType()
+    def __ne__(self, o: object) -> bytes:
+        return b"world"

-    def __lt__(self, o: A) -> LtReturnType:
-        return LtReturnType()
+    def __lt__(self, o: A) -> float:
+        return 3.14

-    def __le__(self, o: A) -> LeReturnType:
-        return LeReturnType()
+    def __le__(self, o: A) -> complex:
+        return complex(0.5, -0.5)

-    def __gt__(self, o: A) -> GtReturnType:
-        return GtReturnType()
+    def __gt__(self, o: A) -> tuple:
+        return (1, 2, 3)

-    def __ge__(self, o: A) -> GeReturnType:
-        return GeReturnType()
+    def __ge__(self, o: A) -> list:
+        return [1, 2, 3]

 a = (A(), A())

 reveal_type(a == a)  # revealed: bool
 reveal_type(a != a)  # revealed: bool
-reveal_type(a < a)  # revealed: LtReturnType | Literal[False]
-reveal_type(a <= a)  # revealed: LeReturnType | Literal[True]
-reveal_type(a > a)  # revealed: GtReturnType | Literal[False]
-reveal_type(a >= a)  # revealed: GeReturnType | Literal[True]
+reveal_type(a < a)  # revealed: float | Literal[False]
+reveal_type(a <= a)  # revealed: complex | Literal[True]
+reveal_type(a > a)  # revealed: tuple | Literal[False]
+reveal_type(a >= a)  # revealed: list | Literal[True]

 # If lexicographic comparison is finished before comparing A()
 b = ("1_foo", A())
@@ -193,13 +183,11 @@ reveal_type(b <= c)  # revealed: Literal[True]
 reveal_type(b > c)  # revealed: Literal[False]
 reveal_type(b >= c)  # revealed: Literal[False]

-class LtReturnTypeOnB: ...
-
 class B:
-    def __lt__(self, o: B) -> LtReturnTypeOnB:
-        return LtReturnTypeOnB()
+    def __lt__(self, o: B) -> set:
+        return set()

-reveal_type((A(), B()) < (A(), B()))  # revealed: LtReturnType | LtReturnTypeOnB | Literal[False]
+reveal_type((A(), B()) < (A(), B()))  # revealed: float | set | Literal[False]
 ```

 #### Special Handling of Eq and NotEq in Lexicographic Comparisons
@@ -334,61 +322,3 @@ 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(),)
-```
--- a/crates/red_knot_python_semantic/resources/mdtest/comparison/unions.md
+++ b/crates/red_knot_python_semantic/resources/mdtest/comparison/unions.md
--- a/crates/red_knot_python_semantic/resources/mdtest/comparison/unsupported.md
+++ b/crates/red_knot_python_semantic/resources/mdtest/comparison/unsupported.md
@@ -9,22 +9,28 @@ def _(flag: bool, flag1: bool, flag2: bool):
    b = 0 not in 10  # error: "Operator `not in` is not supported for types `Literal[0]` and `Literal[10]`"
    reveal_type(b)  # revealed: bool

-    # error: [unsupported-operator] "Operator `<` is not supported for types `object` and `int`, in comparing `object` with `Literal[5]`"
+    # TODO: should error, once operand type check is implemented
+    # ("Operator `<` is not supported for types `object` and `int`")
    c = object() < 5
-    reveal_type(c)  # revealed: Unknown
+    # TODO: should be Unknown, once operand type check is implemented
+    reveal_type(c)  # revealed: bool

-    # error: [unsupported-operator] "Operator `<` is not supported for types `int` and `object`, in comparing `Literal[5]` with `object`"
+    # TODO: should error, once operand type check is implemented
+    # ("Operator `<` is not supported for types `int` and `object`")
    d = 5 < object()
-    reveal_type(d)  # revealed: Unknown
+    # TODO: should be Unknown, once operand type check is implemented
+    reveal_type(d)  # revealed: bool

    int_literal_or_str_literal = 1 if flag else "foo"
    # error: "Operator `in` is not supported for types `Literal[42]` and `Literal[1]`, in comparing `Literal[42]` with `Literal[1, "foo"]`"
    e = 42 in int_literal_or_str_literal
    reveal_type(e)  # revealed: bool

-    # error: [unsupported-operator] "Operator `<` is not supported for types `int` and `str`, in comparing `tuple[Literal[1], Literal[2]]` with `tuple[Literal[1], Literal["hello"]]`"
+    # TODO: should error, need to check if __lt__ signature is valid for right operand
+    # error may be "Operator `<` is not supported for types `int` and `str`, in comparing `tuple[Literal[1], Literal[2]]` with `tuple[Literal[1], Literal["hello"]]`
    f = (1, 2) < (1, "hello")
-    reveal_type(f)  # revealed: Unknown
+    # TODO: should be Unknown, once operand type check is implemented
+    reveal_type(f)  # revealed: bool

    # error: [unsupported-operator] "Operator `<` is not supported for types `A` and `A`, in comparing `tuple[bool, A]` with `tuple[bool, A]`"
    g = (flag1, A()) < (flag2, A())
--- a/crates/red_knot_python_semantic/resources/mdtest/conditional/if_expression.md
+++ b/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`"
-3 if NotBoolable() else 4
-```
--- a/crates/red_knot_python_semantic/resources/mdtest/conditional/if_statement.md
+++ b/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`"
-if NotBoolable():
-    ...
-# error: [unsupported-bool-conversion] "Boolean conversion is unsupported for type `NotBoolable`"
-elif NotBoolable():
-    ...
-```
--- a/crates/red_knot_python_semantic/resources/mdtest/conditional/match.md
+++ b/crates/red_knot_python_semantic/resources/mdtest/conditional/match.md
@@ -0,0 +1,45 @@
+# Pattern matching
+
+## With wildcard
+
+```py
+def _(target: int):
+    match target:
+        case 1:
+            y = 2
+        case _:
+            y = 3
+
+    reveal_type(y)  # revealed: Literal[2, 3]
+```
+
+## Without wildcard
+
+```py
+def _(target: int):
+    match target:
+        case 1:
+            y = 2
+        case 2:
+            y = 3
+
+    # revealed: Literal[2, 3]
+    # error: [possibly-unresolved-reference]
+    reveal_type(y)
+```
+
+## Basic match
+
+```py
+def _(target: int):
+    y = 1
+    y = 2
+
+    match target:
+        case 1:
+            y = 3
+        case 2:
+            y = 4
+
+    reveal_type(y)  # revealed: Literal[2, 3, 4]
+```
--- a/crates/red_knot_python_semantic/resources/mdtest/declaration/error.md
+++ b/crates/red_knot_python_semantic/resources/mdtest/declaration/error.md
--- a/crates/red_knot_python_semantic/resources/mdtest/directives/assert_type.md
+++ b/crates/red_knot_python_semantic/resources/mdtest/directives/assert_type.md
@@ -55,7 +55,7 @@ def _(a: type[int]):
 from typing import Any
 from typing_extensions import Literal, assert_type

-from ty_extensions import Unknown
+from knot_extensions import Unknown

 # Any and Unknown are considered equivalent
 def _(a: Unknown, b: Any):
@@ -78,9 +78,9 @@ def _(a: type[Unknown], b: type[Any]):
 Tuple types with the same elements are the same.

 ```py
-from typing_extensions import Any, assert_type
+from typing_extensions import assert_type

-from ty_extensions import Unknown
+from knot_extensions import Unknown

 def _(a: tuple[int, str, bytes]):
    assert_type(a, tuple[int, str, bytes])  # fine
@@ -110,8 +110,10 @@ python-version = "3.10"
 from typing_extensions import assert_type

 def _(a: str | int):
-    assert_type(a, str | int)
-    assert_type(a, int | str)
+    assert_type(a, str | int)  # fine
+
+    # TODO: Order-independent union handling in type equivalence
+    assert_type(a, int | str)  # error: [type-assertion-failure]
 ```

 ## Intersections
@@ -122,7 +124,7 @@ regardless of order.
 ```py
 from typing_extensions import assert_type

-from ty_extensions import Intersection, Not
+from knot_extensions import Intersection, Not

 class A: ...
 class B: ...
@@ -133,6 +135,8 @@ def _(a: A):
    if isinstance(a, B) and not isinstance(a, C) and not isinstance(a, D):
        reveal_type(a)  # revealed: A & B & ~C & ~D

-        assert_type(a, Intersection[A, B, Not[C], Not[D]])
-        assert_type(a, Intersection[B, A, Not[D], Not[C]])
+        assert_type(a, Intersection[A, B, Not[C], Not[D]])  # fine
+
+        # TODO: Order-independent intersection handling in type equivalence
+        assert_type(a, Intersection[B, A, Not[D], Not[C]])  # error: [type-assertion-failure]
 ```
--- a/crates/red_knot_python_semantic/resources/mdtest/directives/cast.md
+++ b/crates/red_knot_python_semantic/resources/mdtest/directives/cast.md
@@ -0,0 +1,27 @@
+# `cast`
+
+`cast()` takes two arguments, one type and one value, and returns a value of the given type.
+
+The (inferred) type of the value and the given type do not need to have any correlation.
+
+```py
+from typing import Literal, cast
+
+reveal_type(True)  # revealed: Literal[True]
+reveal_type(cast(str, True))  # revealed: str
+reveal_type(cast("str", True))  # revealed: str
+
+reveal_type(cast(int | str, 1))  # revealed: int | str
+
+# error: [invalid-type-form]
+reveal_type(cast(Literal, True))  # revealed: Unknown
+
+# TODO: These should be errors
+cast(1)
+cast(str)
+cast(str, b"ar", "foo")
+
+# TODO: Either support keyword arguments properly,
+# or give a comprehensible error message saying they're unsupported
+cast(val="foo", typ=int)  # error: [unresolved-reference] "Name `foo` used when not defined"
+```
--- a/crates/red_knot_python_semantic/resources/mdtest/exception/basic.md
+++ b/crates/red_knot_python_semantic/resources/mdtest/exception/basic.md
@@ -124,49 +124,42 @@ def _(e: Exception | type[Exception] | None):
 ## Exception cause is not an exception

 ```py
-def _():
-    try:
-        raise EOFError() from GeneratorExit  # fine
-    except:
-        ...
+try:
+    raise EOFError() from GeneratorExit  # fine
+except:
+    ...

-def _():
-    try:
-        raise StopIteration from MemoryError()  # fine
-    except:
-        ...
+try:
+    raise StopIteration from MemoryError()  # fine
+except:
+    ...

-def _():
-    try:
-        raise BufferError() from None  # fine
-    except:
-        ...
+try:
+    raise BufferError() from None  # fine
+except:
+    ...

-def _():
-    try:
-        raise ZeroDivisionError from False  # error: [invalid-raise]
-    except:
-        ...
+try:
+    raise ZeroDivisionError from False  # error: [invalid-raise]
+except:
+    ...

-def _():
-    try:
-        raise SystemExit from bool()  # error: [invalid-raise]
-    except:
-        ...
+try:
+    raise SystemExit from bool()  # error: [invalid-raise]
+except:
+    ...

-def _():
-    try:
-        raise
-    except KeyboardInterrupt as e:  # fine
-        reveal_type(e)  # revealed: KeyboardInterrupt
-        raise LookupError from e  # fine
+try:
+    raise
+except KeyboardInterrupt as e:  # fine
+    reveal_type(e)  # revealed: KeyboardInterrupt
+    raise LookupError from e  # fine

-def _():
-    try:
-        raise
-    except int as e:  # error: [invalid-exception-caught]
-        reveal_type(e)  # revealed: Unknown
-        raise KeyError from e
+try:
+    raise
+except int as e:  # error: [invalid-exception-caught]
+    reveal_type(e)  # revealed: Unknown
+    raise KeyError from e

 def _(e: Exception | type[Exception]):
    raise ModuleNotFoundError from e  # fine
--- a/crates/red_knot_python_semantic/resources/mdtest/exception/control_flow.md
+++ b/crates/red_knot_python_semantic/resources/mdtest/exception/control_flow.md
@@ -29,7 +29,7 @@ completing. The type of `x` at the beginning of the `except` suite in this examp
 `x = could_raise_returns_str()` redefinition, but we *also* could have jumped to the `except` suite
 *after* that redefinition.

-```py
+```py path=union_type_inferred.py
 def could_raise_returns_str() -> str:
    return "foo"

@@ -50,7 +50,10 @@ reveal_type(x)  # revealed: str | Literal[2]
 If `x` has the same type at the end of both branches, however, the branches unify and `x` is not
 inferred as having a union type following the `try`/`except` block:

-```py
+```py path=branches_unify_to_non_union_type.py
+def could_raise_returns_str() -> str:
+    return "foo"
+
 x = 1

 try:
@@ -130,7 +133,7 @@ the `except` suite:
 - At the end of `else`, `x == 3`
 - At the end of `except`, `x == 2`

-```py
+```py path=single_except.py
 def could_raise_returns_str() -> str:
    return "foo"

@@ -158,6 +161,9 @@ been executed in its entirety, or the `try` suite and the `else` suite must both
 in their entireties:

 ```py
+def could_raise_returns_str() -> str:
+    return "foo"
+
 x = 1

 try:
@@ -186,7 +192,7 @@ A `finally` suite is *always* executed. As such, if we reach the `reveal_type` c
 this example, we know that `x` *must* have been reassigned to `2` during the `finally` suite. The
 type of `x` at the end of the example is therefore `Literal[2]`:

-```py
+```py path=redef_in_finally.py
 def could_raise_returns_str() -> str:
    return "foo"

@@ -211,7 +217,10 @@ at this point than there were when we were inside the `finally` block.
 (Our current model does *not* correctly infer the types *inside* `finally` suites, however; this is
 still a TODO item for us.)

-```py
+```py path=no_redef_in_finally.py
+def could_raise_returns_str() -> str:
+    return "foo"
+
 x = 1

 try:
@@ -240,35 +249,31 @@ suites:
    exception raised in the `except` suite to cause us to jump to the `finally` suite before the
    `except` suite ran to completion

-```py
-class A: ...
-class B: ...
-class C: ...
+```py path=redef_in_finally.py
+def could_raise_returns_str() -> str:
+    return "foo"

-def could_raise_returns_A() -> A:
-    return A()
+def could_raise_returns_bytes() -> bytes:
+    return b"foo"

-def could_raise_returns_B() -> B:
-    return B()
-
-def could_raise_returns_C() -> C:
-    return C()
+def could_raise_returns_bool() -> bool:
+    return True

 x = 1

 try:
    reveal_type(x)  # revealed: Literal[1]
-    x = could_raise_returns_A()
-    reveal_type(x)  # revealed: A
+    x = could_raise_returns_str()
+    reveal_type(x)  # revealed: str
 except TypeError:
-    reveal_type(x)  # revealed: Literal[1] | A
-    x = could_raise_returns_B()
-    reveal_type(x)  # revealed: B
-    x = could_raise_returns_C()
-    reveal_type(x)  # revealed: C
+    reveal_type(x)  # revealed: Literal[1] | str
+    x = could_raise_returns_bytes()
+    reveal_type(x)  # revealed: bytes
+    x = could_raise_returns_bool()
+    reveal_type(x)  # revealed: bool
 finally:
-    # TODO: should be `Literal[1] | A | B | C`
-    reveal_type(x)  # revealed: A | C
+    # TODO: should be `Literal[1] | str | bytes | bool`
+    reveal_type(x)  # revealed: str | bool
    x = 2
    reveal_type(x)  # revealed: Literal[2]

@@ -281,61 +286,76 @@ itself. (In some control-flow possibilities, some exceptions were merely *suspen
 `finally` suite; these lead to the scope's termination following the conclusion of the `finally`
 suite.)

-```py
+```py path=no_redef_in_finally.py
+def could_raise_returns_str() -> str:
+    return "foo"
+
+def could_raise_returns_bytes() -> bytes:
+    return b"foo"
+
+def could_raise_returns_bool() -> bool:
+    return True
+
 x = 1

 try:
    reveal_type(x)  # revealed: Literal[1]
-    x = could_raise_returns_A()
-    reveal_type(x)  # revealed: A
+    x = could_raise_returns_str()
+    reveal_type(x)  # revealed: str
 except TypeError:
-    reveal_type(x)  # revealed: Literal[1] | A
-    x = could_raise_returns_B()
-    reveal_type(x)  # revealed: B
-    x = could_raise_returns_C()
-    reveal_type(x)  # revealed: C
+    reveal_type(x)  # revealed: Literal[1] | str
+    x = could_raise_returns_bytes()
+    reveal_type(x)  # revealed: bytes
+    x = could_raise_returns_bool()
+    reveal_type(x)  # revealed: bool
 finally:
-    # TODO: should be `Literal[1] | A | B | C`
-    reveal_type(x)  # revealed: A | C
+    # TODO: should be `Literal[1] | str | bytes | bool`
+    reveal_type(x)  # revealed: str | bool

-reveal_type(x)  # revealed: A | C
+reveal_type(x)  # revealed: str | bool
 ```

 An example with multiple `except` branches and a `finally` branch:

-```py
-class D: ...
-class E: ...
+```py path=multiple_except_branches.py
+def could_raise_returns_str() -> str:
+    return "foo"

-def could_raise_returns_D() -> D:
-    return D()
+def could_raise_returns_bytes() -> bytes:
+    return b"foo"

-def could_raise_returns_E() -> E:
-    return E()
+def could_raise_returns_bool() -> bool:
+    return True
+
+def could_raise_returns_memoryview() -> memoryview:
+    return memoryview(b"")
+
+def could_raise_returns_float() -> float:
+    return 3.14

 x = 1

 try:
    reveal_type(x)  # revealed: Literal[1]
-    x = could_raise_returns_A()
-    reveal_type(x)  # revealed: A
+    x = could_raise_returns_str()
+    reveal_type(x)  # revealed: str
 except TypeError:
-    reveal_type(x)  # revealed: Literal[1] | A
-    x = could_raise_returns_B()
-    reveal_type(x)  # revealed: B
-    x = could_raise_returns_C()
-    reveal_type(x)  # revealed: C
+    reveal_type(x)  # revealed: Literal[1] | str
+    x = could_raise_returns_bytes()
+    reveal_type(x)  # revealed: bytes
+    x = could_raise_returns_bool()
+    reveal_type(x)  # revealed: bool
 except ValueError:
-    reveal_type(x)  # revealed: Literal[1] | A
-    x = could_raise_returns_D()
-    reveal_type(x)  # revealed: D
-    x = could_raise_returns_E()
-    reveal_type(x)  # revealed: E
+    reveal_type(x)  # revealed: Literal[1] | str
+    x = could_raise_returns_memoryview()
+    reveal_type(x)  # revealed: memoryview
+    x = could_raise_returns_float()
+    reveal_type(x)  # revealed: float
 finally:
-    # TODO: should be `Literal[1] | A | B | C | D | E`
-    reveal_type(x)  # revealed: A | C | E
+    # TODO: should be `Literal[1] | str | bytes | bool | memoryview | float`
+    reveal_type(x)  # revealed: str | bool | float

-reveal_type(x)  # revealed: A | C | E
+reveal_type(x)  # revealed: str | bool | float
 ```

 ## Combining `except`, `else` and `finally` branches
@@ -344,94 +364,100 @@ If the exception handler has an `else` branch, we must also take into account th
 control flow could have jumped to the `finally` suite from partway through the `else` suite due to
 an exception raised *there*.

-```py
-class A: ...
-class B: ...
-class C: ...
-class D: ...
-class E: ...
+```py path=single_except_branch.py
+def could_raise_returns_str() -> str:
+    return "foo"

-def could_raise_returns_A() -> A:
-    return A()
+def could_raise_returns_bytes() -> bytes:
+    return b"foo"

-def could_raise_returns_B() -> B:
-    return B()
+def could_raise_returns_bool() -> bool:
+    return True

-def could_raise_returns_C() -> C:
-    return C()
+def could_raise_returns_memoryview() -> memoryview:
+    return memoryview(b"")

-def could_raise_returns_D() -> D:
-    return D()
-
-def could_raise_returns_E() -> E:
-    return E()
+def could_raise_returns_float() -> float:
+    return 3.14

 x = 1

 try:
    reveal_type(x)  # revealed: Literal[1]
-    x = could_raise_returns_A()
-    reveal_type(x)  # revealed: A
+    x = could_raise_returns_str()
+    reveal_type(x)  # revealed: str
 except TypeError:
-    reveal_type(x)  # revealed: Literal[1] | A
-    x = could_raise_returns_B()
-    reveal_type(x)  # revealed: B
-    x = could_raise_returns_C()
-    reveal_type(x)  # revealed: C
+    reveal_type(x)  # revealed: Literal[1] | str
+    x = could_raise_returns_bytes()
+    reveal_type(x)  # revealed: bytes
+    x = could_raise_returns_bool()
+    reveal_type(x)  # revealed: bool
 else:
-    reveal_type(x)  # revealed: A
-    x = could_raise_returns_D()
-    reveal_type(x)  # revealed: D
-    x = could_raise_returns_E()
-    reveal_type(x)  # revealed: E
+    reveal_type(x)  # revealed: str
+    x = could_raise_returns_memoryview()
+    reveal_type(x)  # revealed: memoryview
+    x = could_raise_returns_float()
+    reveal_type(x)  # revealed: float
 finally:
-    # TODO: should be `Literal[1] | A | B | C | D | E`
-    reveal_type(x)  # revealed: C | E
+    # TODO: should be `Literal[1] | str | bytes | bool | memoryview | float`
+    reveal_type(x)  # revealed: bool | float

-reveal_type(x)  # revealed: C | E
+reveal_type(x)  # revealed: bool | float
 ```

 The same again, this time with multiple `except` branches:

-```py
-class F: ...
-class G: ...
+```py path=multiple_except_branches.py
+def could_raise_returns_str() -> str:
+    return "foo"

-def could_raise_returns_F() -> F:
-    return F()
+def could_raise_returns_bytes() -> bytes:
+    return b"foo"

-def could_raise_returns_G() -> G:
-    return G()
+def could_raise_returns_bool() -> bool:
+    return True
+
+def could_raise_returns_memoryview() -> memoryview:
+    return memoryview(b"")
+
+def could_raise_returns_float() -> float:
+    return 3.14
+
+def could_raise_returns_range() -> range:
+    return range(42)
+
+def could_raise_returns_slice() -> slice:
+    return slice(None)

 x = 1

 try:
    reveal_type(x)  # revealed: Literal[1]
-    x = could_raise_returns_A()
-    reveal_type(x)  # revealed: A
+    x = could_raise_returns_str()
+    reveal_type(x)  # revealed: str
 except TypeError:
-    reveal_type(x)  # revealed: Literal[1] | A
-    x = could_raise_returns_B()
-    reveal_type(x)  # revealed: B
-    x = could_raise_returns_C()
-    reveal_type(x)  # revealed: C
+    reveal_type(x)  # revealed: Literal[1] | str
+    x = could_raise_returns_bytes()
+    reveal_type(x)  # revealed: bytes
+    x = could_raise_returns_bool()
+    reveal_type(x)  # revealed: bool
 except ValueError:
-    reveal_type(x)  # revealed: Literal[1] | A
-    x = could_raise_returns_D()
-    reveal_type(x)  # revealed: D
-    x = could_raise_returns_E()
-    reveal_type(x)  # revealed: E
+    reveal_type(x)  # revealed: Literal[1] | str
+    x = could_raise_returns_memoryview()
+    reveal_type(x)  # revealed: memoryview
+    x = could_raise_returns_float()
+    reveal_type(x)  # revealed: float
 else:
-    reveal_type(x)  # revealed: A
-    x = could_raise_returns_F()
-    reveal_type(x)  # revealed: F
-    x = could_raise_returns_G()
-    reveal_type(x)  # revealed: G
+    reveal_type(x)  # revealed: str
+    x = could_raise_returns_range()
+    reveal_type(x)  # revealed: range
+    x = could_raise_returns_slice()
+    reveal_type(x)  # revealed: slice
 finally:
-    # TODO: should be `Literal[1] | A | B | C | D | E | F | G`
-    reveal_type(x)  # revealed: C | E | G
+    # TODO: should be `Literal[1] | str | bytes | bool | memoryview | float | range | slice`
+    reveal_type(x)  # revealed: bool | float | slice

-reveal_type(x)  # revealed: C | E | G
+reveal_type(x)  # revealed: bool | float | slice
 ```

 ## Nested `try`/`except` blocks
@@ -445,101 +471,92 @@ a suite containing statements that could possibly raise exceptions, which would
 jumping out of that suite prior to the suite running to completion.

 ```py
-class A: ...
-class B: ...
-class C: ...
-class D: ...
-class E: ...
-class F: ...
-class G: ...
-class H: ...
-class I: ...
-class J: ...
-class K: ...
+def could_raise_returns_str() -> str:
+    return "foo"

-def could_raise_returns_A() -> A:
-    return A()
+def could_raise_returns_bytes() -> bytes:
+    return b"foo"

-def could_raise_returns_B() -> B:
-    return B()
+def could_raise_returns_bool() -> bool:
+    return True

-def could_raise_returns_C() -> C:
-    return C()
+def could_raise_returns_memoryview() -> memoryview:
+    return memoryview(b"")

-def could_raise_returns_D() -> D:
-    return D()
+def could_raise_returns_float() -> float:
+    return 3.14

-def could_raise_returns_E() -> E:
-    return E()
+def could_raise_returns_range() -> range:
+    return range(42)

-def could_raise_returns_F() -> F:
-    return F()
+def could_raise_returns_slice() -> slice:
+    return slice(None)

-def could_raise_returns_G() -> G:
-    return G()
+def could_raise_returns_complex() -> complex:
+    return 3j

-def could_raise_returns_H() -> H:
-    return H()
+def could_raise_returns_bytearray() -> bytearray:
+    return bytearray()

-def could_raise_returns_I() -> I:
-    return I()
+class Foo: ...
+class Bar: ...

-def could_raise_returns_J() -> J:
-    return J()
+def could_raise_returns_Foo() -> Foo:
+    return Foo()

-def could_raise_returns_K() -> K:
-    return K()
+def could_raise_returns_Bar() -> Bar:
+    return Bar()

 x = 1

 try:
    try:
        reveal_type(x)  # revealed: Literal[1]
-        x = could_raise_returns_A()
-        reveal_type(x)  # revealed: A
+        x = could_raise_returns_str()
+        reveal_type(x)  # revealed: str
    except TypeError:
-        reveal_type(x)  # revealed: Literal[1] | A
-        x = could_raise_returns_B()
-        reveal_type(x)  # revealed: B
-        x = could_raise_returns_C()
-        reveal_type(x)  # revealed: C
+        reveal_type(x)  # revealed: Literal[1] | str
+        x = could_raise_returns_bytes()
+        reveal_type(x)  # revealed: bytes
+        x = could_raise_returns_bool()
+        reveal_type(x)  # revealed: bool
    except ValueError:
-        reveal_type(x)  # revealed: Literal[1] | A
-        x = could_raise_returns_D()
-        reveal_type(x)  # revealed: D
-        x = could_raise_returns_E()
-        reveal_type(x)  # revealed: E
+        reveal_type(x)  # revealed: Literal[1] | str
+        x = could_raise_returns_memoryview()
+        reveal_type(x)  # revealed: memoryview
+        x = could_raise_returns_float()
+        reveal_type(x)  # revealed: float
    else:
-        reveal_type(x)  # revealed: A
-        x = could_raise_returns_F()
-        reveal_type(x)  # revealed: F
-        x = could_raise_returns_G()
-        reveal_type(x)  # revealed: G
+        reveal_type(x)  # revealed: str
+        x = could_raise_returns_range()
+        reveal_type(x)  # revealed: range
+        x = could_raise_returns_slice()
+        reveal_type(x)  # revealed: slice
    finally:
-        # TODO: should be `Literal[1] | A | B | C | D | E | F | G`
-        reveal_type(x)  # revealed: C | E | G
+        # TODO: should be `Literal[1] | str | bytes | bool | memoryview | float | range | slice`
+        reveal_type(x)  # revealed: bool | float | slice
        x = 2
        reveal_type(x)  # revealed: Literal[2]
    reveal_type(x)  # revealed: Literal[2]
 except:
-    reveal_type(x)  # revealed: Literal[1, 2] | A | B | C | D | E | F | G
-    x = could_raise_returns_H()
-    reveal_type(x)  # revealed: H
-    x = could_raise_returns_I()
-    reveal_type(x)  # revealed: I
+    reveal_type(x)  # revealed: Literal[1, 2] | str | bytes | bool | memoryview | float | range | slice
+    x = could_raise_returns_complex()
+    reveal_type(x)  # revealed: complex
+    x = could_raise_returns_bytearray()
+    reveal_type(x)  # revealed: bytearray
 else:
    reveal_type(x)  # revealed: Literal[2]
-    x = could_raise_returns_J()
-    reveal_type(x)  # revealed: J
-    x = could_raise_returns_K()
-    reveal_type(x)  # revealed: K
+    x = could_raise_returns_Foo()
+    reveal_type(x)  # revealed: Foo
+    x = could_raise_returns_Bar()
+    reveal_type(x)  # revealed: Bar
 finally:
-    # TODO: should be `Literal[1, 2] | A | B | C | D | E | F | G | H | I | J | K`
-    reveal_type(x)  # revealed: I | K
+    # TODO: should be `Literal[1, 2] | str | bytes | bool | memoryview | float | range | slice | complex | bytearray | Foo | Bar`
+    reveal_type(x)  # revealed: bytearray | Bar

 # Either one `except` branch or the `else`
 # must have been taken and completed to get here:
-reveal_type(x)  # revealed: I | K
+reveal_type(x)  # revealed: bytearray | Bar
 ```

 ## Nested scopes inside `try` blocks
@@ -548,64 +565,58 @@ Shadowing a variable in an inner scope has no effect on type inference of the va
 in the outer scope:

 ```py
-class A: ...
-class B: ...
-class C: ...
-class D: ...
-class E: ...
+def could_raise_returns_str() -> str:
+    return "foo"

-def could_raise_returns_A() -> A:
-    return A()
+def could_raise_returns_bytes() -> bytes:
+    return b"foo"

-def could_raise_returns_B() -> B:
-    return B()
+def could_raise_returns_range() -> range:
+    return range(42)

-def could_raise_returns_C() -> C:
-    return C()
+def could_raise_returns_bytearray() -> bytearray:
+    return bytearray()

-def could_raise_returns_D() -> D:
-    return D()
-
-def could_raise_returns_E() -> E:
-    return E()
+def could_raise_returns_float() -> float:
+    return 3.14

 x = 1

 try:

-    def foo(param=could_raise_returns_A()):
-        x = could_raise_returns_A()
+    def foo(param=could_raise_returns_str()):
+        x = could_raise_returns_str()

        try:
-            reveal_type(x)  # revealed: A
-            x = could_raise_returns_B()
-            reveal_type(x)  # revealed: B
+            reveal_type(x)  # revealed: str
+            x = could_raise_returns_bytes()
+            reveal_type(x)  # revealed: bytes
        except:
-            reveal_type(x)  # revealed: A | B
-            x = could_raise_returns_C()
-            reveal_type(x)  # revealed: C
-            x = could_raise_returns_D()
-            reveal_type(x)  # revealed: D
+            reveal_type(x)  # revealed: str | bytes
+            x = could_raise_returns_bytearray()
+            reveal_type(x)  # revealed: bytearray
+            x = could_raise_returns_float()
+            reveal_type(x)  # revealed: float
        finally:
-            # TODO: should be `A | B | C | D`
-            reveal_type(x)  # revealed: B | D
-        reveal_type(x)  # revealed: B | D
+            # TODO: should be `str | bytes | bytearray | float`
+            reveal_type(x)  # revealed: bytes | float
+        reveal_type(x)  # revealed: bytes | float
    x = foo
-    reveal_type(x)  # revealed: def foo(param=A) -> Unknown
+    reveal_type(x)  # revealed: Literal[foo]
 except:
-    reveal_type(x)  # revealed: Literal[1] | (def foo(param=A) -> Unknown)
+    reveal_type(x)  # revealed: Literal[1] | Literal[foo]

    class Bar:
-        x = could_raise_returns_E()
-        reveal_type(x)  # revealed: E
+        x = could_raise_returns_range()
+        reveal_type(x)  # revealed: range

    x = Bar
-    reveal_type(x)  # revealed: <class 'Bar'>
+    reveal_type(x)  # revealed: Literal[Bar]
 finally:
-    # TODO: should be `Literal[1] | <class 'foo'> | <class 'Bar'>`
-    reveal_type(x)  # revealed: (def foo(param=A) -> Unknown) | <class 'Bar'>
+    # TODO: should be `Literal[1] | Literal[foo] | Literal[Bar]`
+    reveal_type(x)  # revealed: Literal[foo] | Literal[Bar]

-reveal_type(x)  # revealed: (def foo(param=A) -> Unknown) | <class 'Bar'>
+reveal_type(x)  # revealed: Literal[foo] | Literal[Bar]
 ```

 [1]: https://astral-sh.notion.site/Exception-handler-control-flow-11348797e1ca80bb8ce1e9aedbbe439d
--- a/Show More
+++ b/Show More
Author	SHA1	Message	Date
Charlie Marsh	95c4457742	Add docs	2025-01-16 20:29:45 -05:00
InSyncWithFoo	992c65539e	[`flake8-pytest-style`] Do not emit diagnostics for empty `for` loops (`PT012`, `PT031`)	2025-01-17 00:12:53 +00:00