Experiment: allow functions to be redefined (same signature)

## Summary

Resolves https://github.com/astral-sh/ty/issues/485.

`infer_binary_intersection_type_comparison()` now checks for all
positive members before concluding that an operation is unsupported for
a given intersection type.

## Test Plan

Markdown tests.

---------

Co-authored-by: David Peter <mail@david-peter.de>

.gitattributes

@@ -21,6 +21,7 @@ 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
+ty.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
 *.md.snap linguist-language=Markdown

.github/CODEOWNERS

@@ -14,11 +14,11 @@
 # flake8-pyi
 /crates/ruff_linter/src/rules/flake8_pyi/ @AlexWaygood
 
-# Script for fuzzing the parser/red-knot etc.
+# Script for fuzzing the parser/ty etc.
 /python/py-fuzzer/ @AlexWaygood
 
-# red-knot
-/crates/red_knot* @carljm @MichaReiser @AlexWaygood @sharkdp @dcreager
+# ty
+/crates/ty* @carljm @MichaReiser @AlexWaygood @sharkdp @dcreager
 /crates/ruff_db/ @carljm @MichaReiser @AlexWaygood @sharkdp @dcreager
-/scripts/knot_benchmark/ @carljm @MichaReiser @AlexWaygood @sharkdp @dcreager
-/crates/red_knot_python_semantic @carljm @AlexWaygood @sharkdp @dcreager
+/scripts/ty_benchmark/ @carljm @MichaReiser @AlexWaygood @sharkdp @dcreager
+/crates/ty_python_semantic @carljm @AlexWaygood @sharkdp @dcreager

.github/ISSUE_TEMPLATE/config.yml

@@ -1,5 +1,8 @@
 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.

.github/PULL_REQUEST_TEMPLATE.md

@@ -1,8 +1,9 @@
 <!--
-Thank you for contributing to Ruff! To help us out with reviewing, please consider the following:
+Thank you for contributing to Ruff/ty! To help us out with reviewing, please consider the following:
 
 - Does this pull request include a summary of the change? (See below.)
-- Does this pull request include a descriptive title?
+- Does this pull request include a descriptive title? (Please prefix with `[ty]` for ty pull
+  requests.)
 - Does this pull request include references to any relevant issues?
 -->
 

.github/mypy-primer-ty.toml

@@ -0,0 +1,8 @@
+#:schema ../ty.schema.json
+# Configuration overrides for the mypy primer run
+
+# Enable off-by-default rules.
+[rules]
+possibly-unresolved-reference = "warn"
+unused-ignore-comment = "warn"
+division-by-zero = "warn"

.github/workflows/build-binaries.yml

@@ -43,7 +43,7 @@ jobs:
         with:
           submodules: recursive
           persist-credentials: false
-      - uses: actions/setup-python@8d9ed9ac5c53483de85588cdf95a591a75ab9f55 # v5.5.0
+      - uses: actions/setup-python@a26af69be951a213d495a4c3e4e4022e16d87065 # v5.6.0
         with:
           python-version: ${{ env.PYTHON_VERSION }}
       - name: "Prep README.md"
@@ -72,7 +72,7 @@ jobs:
         with:
           submodules: recursive
           persist-credentials: false
-      - uses: actions/setup-python@8d9ed9ac5c53483de85588cdf95a591a75ab9f55 # v5.5.0
+      - uses: actions/setup-python@a26af69be951a213d495a4c3e4e4022e16d87065 # v5.6.0
         with:
           python-version: ${{ env.PYTHON_VERSION }}
           architecture: x64
@@ -114,7 +114,7 @@ jobs:
         with:
           submodules: recursive
           persist-credentials: false
-      - uses: actions/setup-python@8d9ed9ac5c53483de85588cdf95a591a75ab9f55 # v5.5.0
+      - uses: actions/setup-python@a26af69be951a213d495a4c3e4e4022e16d87065 # v5.6.0
         with:
           python-version: ${{ env.PYTHON_VERSION }}
           architecture: arm64
@@ -170,7 +170,7 @@ jobs:
         with:
           submodules: recursive
           persist-credentials: false
-      - uses: actions/setup-python@8d9ed9ac5c53483de85588cdf95a591a75ab9f55 # v5.5.0
+      - uses: actions/setup-python@a26af69be951a213d495a4c3e4e4022e16d87065 # v5.6.0
         with:
           python-version: ${{ env.PYTHON_VERSION }}
           architecture: ${{ matrix.platform.arch }}
@@ -223,7 +223,7 @@ jobs:
         with:
           submodules: recursive
           persist-credentials: false
-      - uses: actions/setup-python@8d9ed9ac5c53483de85588cdf95a591a75ab9f55 # v5.5.0
+      - uses: actions/setup-python@a26af69be951a213d495a4c3e4e4022e16d87065 # v5.6.0
         with:
           python-version: ${{ env.PYTHON_VERSION }}
           architecture: x64
@@ -298,7 +298,7 @@ jobs:
         with:
           submodules: recursive
           persist-credentials: false
-      - uses: actions/setup-python@8d9ed9ac5c53483de85588cdf95a591a75ab9f55 # v5.5.0
+      - uses: actions/setup-python@a26af69be951a213d495a4c3e4e4022e16d87065 # v5.6.0
         with:
           python-version: ${{ env.PYTHON_VERSION }}
       - name: "Prep README.md"
@@ -310,7 +310,7 @@ jobs:
           manylinux: auto
           docker-options: ${{ matrix.platform.maturin_docker_options }}
           args: --release --locked --out dist
-      - uses: uraimo/run-on-arch-action@ac33288c3728ca72563c97b8b88dda5a65a84448 # v2
+      - uses: uraimo/run-on-arch-action@d94c13912ea685de38fccc1109385b83fd79427d # v3.0.1
         if: ${{ matrix.platform.arch != 'ppc64' && matrix.platform.arch != 'ppc64le'}}
         name: Test wheel
         with:
@@ -363,7 +363,7 @@ jobs:
         with:
           submodules: recursive
           persist-credentials: false
-      - uses: actions/setup-python@8d9ed9ac5c53483de85588cdf95a591a75ab9f55 # v5.5.0
+      - uses: actions/setup-python@a26af69be951a213d495a4c3e4e4022e16d87065 # v5.6.0
         with:
           python-version: ${{ env.PYTHON_VERSION }}
           architecture: x64
@@ -429,7 +429,7 @@ jobs:
         with:
           submodules: recursive
           persist-credentials: false
-      - uses: actions/setup-python@8d9ed9ac5c53483de85588cdf95a591a75ab9f55 # v5.5.0
+      - uses: actions/setup-python@a26af69be951a213d495a4c3e4e4022e16d87065 # v5.6.0
         with:
           python-version: ${{ env.PYTHON_VERSION }}
       - name: "Prep README.md"
@@ -441,7 +441,7 @@ jobs:
           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@d94c13912ea685de38fccc1109385b83fd79427d # v3.0.1
         name: Test wheel
         with:
           arch: ${{ matrix.platform.arch }}

.github/workflows/build-docker.yml

@@ -38,9 +38,9 @@ jobs:
           submodules: recursive
           persist-credentials: false
 
-      - uses: docker/setup-buildx-action@b5ca514318bd6ebac0fb2aedd5d36ec1b5c232a2 # v3
+      - uses: docker/setup-buildx-action@b5ca514318bd6ebac0fb2aedd5d36ec1b5c232a2 # v3.10.0
 
-      - uses: docker/login-action@74a5d142397b4f367a81961eba4e8cd7edddf772 # v3
+      - uses: docker/login-action@74a5d142397b4f367a81961eba4e8cd7edddf772 # v3.4.0
         with:
           registry: ghcr.io
           username: ${{ github.repository_owner }}
@@ -63,7 +63,7 @@ jobs:
 
       - name: Extract metadata (tags, labels) for Docker
         id: meta
-        uses: docker/metadata-action@902fa8ec7d6ecbf8d84d538b9b233a880e428804 # v5
+        uses: docker/metadata-action@902fa8ec7d6ecbf8d84d538b9b233a880e428804 # v5.7.0
         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@1dc73863535b631f98b2378be8619f83b136f4a0 # v6.17.0
         with:
           context: .
           platforms: ${{ matrix.platform }}
@@ -113,17 +113,17 @@ jobs:
     if: ${{ inputs.plan != '' && !fromJson(inputs.plan).announcement_tag_is_implicit }}
     steps:
       - name: Download digests
-        uses: actions/download-artifact@95815c38cf2ff2164869cbab79da8d1f422bc89e # v4.2.1
+        uses: actions/download-artifact@d3f86a106a0bac45b974a628896c90dbdf5c8093 # v4.3.0
         with:
           path: /tmp/digests
           pattern: digests-*
           merge-multiple: true
 
-      - uses: docker/setup-buildx-action@b5ca514318bd6ebac0fb2aedd5d36ec1b5c232a2 # v3
+      - uses: docker/setup-buildx-action@b5ca514318bd6ebac0fb2aedd5d36ec1b5c232a2 # v3.10.0
 
       - name: Extract metadata (tags, labels) for Docker
         id: meta
-        uses: docker/metadata-action@902fa8ec7d6ecbf8d84d538b9b233a880e428804 # v5
+        uses: docker/metadata-action@902fa8ec7d6ecbf8d84d538b9b233a880e428804 # v5.7.0
         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@74a5d142397b4f367a81961eba4e8cd7edddf772 # v3.4.0
         with:
           registry: ghcr.io
           username: ${{ github.repository_owner }}
@@ -167,9 +167,9 @@ jobs:
           - 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@b5ca514318bd6ebac0fb2aedd5d36ec1b5c232a2 # v3.10.0
 
-      - uses: docker/login-action@74a5d142397b4f367a81961eba4e8cd7edddf772 # v3
+      - uses: docker/login-action@74a5d142397b4f367a81961eba4e8cd7edddf772 # v3.4.0
         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@902fa8ec7d6ecbf8d84d538b9b233a880e428804 # v5.7.0
         # 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@1dc73863535b631f98b2378be8619f83b136f4a0 # v6.17.0
         with:
           context: .
           platforms: linux/amd64,linux/arm64
@@ -256,17 +256,17 @@ jobs:
     if: ${{ inputs.plan != '' && !fromJson(inputs.plan).announcement_tag_is_implicit }}
     steps:
       - name: Download digests
-        uses: actions/download-artifact@95815c38cf2ff2164869cbab79da8d1f422bc89e # v4.2.1
+        uses: actions/download-artifact@d3f86a106a0bac45b974a628896c90dbdf5c8093 # v4.3.0
         with:
           path: /tmp/digests
           pattern: digests-*
           merge-multiple: true
 
-      - uses: docker/setup-buildx-action@b5ca514318bd6ebac0fb2aedd5d36ec1b5c232a2 # v3
+      - uses: docker/setup-buildx-action@b5ca514318bd6ebac0fb2aedd5d36ec1b5c232a2 # v3.10.0
 
       - name: Extract metadata (tags, labels) for Docker
         id: meta
-        uses: docker/metadata-action@902fa8ec7d6ecbf8d84d538b9b233a880e428804 # v5
+        uses: docker/metadata-action@902fa8ec7d6ecbf8d84d538b9b233a880e428804 # v5.7.0
         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@74a5d142397b4f367a81961eba4e8cd7edddf772 # v3.4.0
         with:
           registry: ghcr.io
           username: ${{ github.repository_owner }}

.github/workflows/ci.yaml

@@ -36,8 +36,8 @@ jobs:
       code: ${{ steps.check_code.outputs.changed }}
       # Flag that is raised when any code that affects the fuzzer is changed
       fuzz: ${{ steps.check_fuzzer.outputs.changed }}
-      # Flag that is set to "true" when code related to red-knot changes.
-      red_knot: ${{ steps.check_red_knot.outputs.changed }}
+      # Flag that is set to "true" when code related to ty changes.
+      ty: ${{ steps.check_ty.outputs.changed }}
 
       # Flag that is set to "true" when code related to the playground changes.
       playground: ${{ steps.check_playground.outputs.changed }}
@@ -84,7 +84,7 @@ jobs:
           if git diff --quiet "${MERGE_BASE}...HEAD" -- ':Cargo.toml' \
             ':Cargo.lock' \
             ':crates/**' \
-            ':!crates/red_knot*/**' \
+            ':!crates/ty*/**' \
             ':!crates/ruff_python_formatter/**' \
             ':!crates/ruff_formatter/**' \
             ':!crates/ruff_dev/**' \
@@ -145,7 +145,7 @@ jobs:
         run: |
           if git diff --quiet "${MERGE_BASE}...HEAD" -- ':**' \
             ':!**/*.md' \
-            ':crates/red_knot_python_semantic/resources/mdtest/**/*.md' \
+            ':crates/ty_python_semantic/resources/mdtest/**/*.md' \
             ':!docs/**' \
             ':!assets/**' \
             ':.github/workflows/ci.yaml' \
@@ -168,15 +168,15 @@ jobs:
               echo "changed=true" >> "$GITHUB_OUTPUT"
           fi
 
-      - name: Check if the red-knot code changed
-        id: check_red_knot
+      - 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/red_knot*/**' \
+            ':crates/ty*/**' \
             ':crates/ruff_db/**' \
             ':crates/ruff_annotate_snippets/**' \
             ':crates/ruff_python_ast/**' \
@@ -221,7 +221,7 @@ jobs:
       - name: "Clippy"
         run: cargo clippy --workspace --all-targets --all-features --locked -- -D warnings
       - name: "Clippy (wasm)"
-        run: cargo clippy -p ruff_wasm -p red_knot_wasm --target wasm32-unknown-unknown --all-features --locked -- -D warnings
+        run: cargo clippy -p ruff_wasm -p ty_wasm --target wasm32-unknown-unknown --all-features --locked -- -D warnings
 
   cargo-test-linux:
     name: "cargo test (linux)"
@@ -239,21 +239,21 @@ jobs:
       - name: "Install mold"
         uses: rui314/setup-mold@e16410e7f8d9e167b74ad5697a9089a35126eb50 # v1
       - name: "Install cargo nextest"
-        uses: taiki-e/install-action@ab3728c7ba6948b9b429627f4d55a68842b27f18 # v2
+        uses: taiki-e/install-action@941e8a4d9d7cdb696bd4f017cf54aca281f8ffff # v2.51.2
         with:
           tool: cargo-nextest
       - name: "Install cargo insta"
-        uses: taiki-e/install-action@ab3728c7ba6948b9b429627f4d55a68842b27f18 # v2
+        uses: taiki-e/install-action@941e8a4d9d7cdb696bd4f017cf54aca281f8ffff # v2.51.2
         with:
           tool: cargo-insta
-      - name: Red-knot mdtests (GitHub annotations)
-        if: ${{ needs.determine_changes.outputs.red_knot == 'true' }}
+      - 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 red_knot_python_semantic --test mdtest || true
+        run: cargo test -p ty_python_semantic --test mdtest || true
       - name: "Run tests"
         shell: bash
         env:
@@ -268,7 +268,7 @@ 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 red_knot_python_semantic -p red_knot -p red_knot_test -p ruff_db --document-private-items
+      - run: cargo doc --no-deps -p ty_python_semantic -p ty -p ty_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"
@@ -278,8 +278,8 @@ jobs:
           path: target/debug/ruff
       - uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02 # v4.6.2
         with:
-          name: red_knot
-          path: target/debug/red_knot
+          name: ty
+          path: target/debug/ty
 
   cargo-test-linux-release:
     name: "cargo test (linux, release)"
@@ -297,11 +297,11 @@ jobs:
       - name: "Install mold"
         uses: rui314/setup-mold@e16410e7f8d9e167b74ad5697a9089a35126eb50 # v1
       - name: "Install cargo nextest"
-        uses: taiki-e/install-action@ab3728c7ba6948b9b429627f4d55a68842b27f18 # v2
+        uses: taiki-e/install-action@941e8a4d9d7cdb696bd4f017cf54aca281f8ffff # v2.51.2
         with:
           tool: cargo-nextest
       - name: "Install cargo insta"
-        uses: taiki-e/install-action@ab3728c7ba6948b9b429627f4d55a68842b27f18 # v2
+        uses: taiki-e/install-action@941e8a4d9d7cdb696bd4f017cf54aca281f8ffff # v2.51.2
         with:
           tool: cargo-insta
       - name: "Run tests"
@@ -324,7 +324,7 @@ jobs:
       - name: "Install Rust toolchain"
         run: rustup show
       - name: "Install cargo nextest"
-        uses: taiki-e/install-action@ab3728c7ba6948b9b429627f4d55a68842b27f18 # v2
+        uses: taiki-e/install-action@941e8a4d9d7cdb696bd4f017cf54aca281f8ffff # v2.51.2
         with:
           tool: cargo-nextest
       - name: "Run tests"
@@ -362,9 +362,9 @@ jobs:
         run: |
           cd crates/ruff_wasm
           wasm-pack test --node
-      - name: "Test red_knot_wasm"
+      - name: "Test ty_wasm"
         run: |
-          cd crates/red_knot_wasm
+          cd crates/ty_wasm
           wasm-pack test --node
 
   cargo-build-release:
@@ -407,11 +407,11 @@ jobs:
       - name: "Install mold"
         uses: rui314/setup-mold@e16410e7f8d9e167b74ad5697a9089a35126eb50 # v1
       - name: "Install cargo nextest"
-        uses: taiki-e/install-action@ab3728c7ba6948b9b429627f4d55a68842b27f18 # v2
+        uses: taiki-e/install-action@941e8a4d9d7cdb696bd4f017cf54aca281f8ffff # v2.51.2
         with:
           tool: cargo-nextest
       - name: "Install cargo insta"
-        uses: taiki-e/install-action@ab3728c7ba6948b9b429627f4d55a68842b27f18 # v2
+        uses: taiki-e/install-action@941e8a4d9d7cdb696bd4f017cf54aca281f8ffff # v2.51.2
         with:
           tool: cargo-insta
       - name: "Run tests"
@@ -437,7 +437,7 @@ jobs:
       - name: "Install Rust toolchain"
         run: rustup show
       - name: "Install cargo-binstall"
-        uses: cargo-bins/cargo-binstall@63aaa5c1932cebabc34eceda9d92a70215dcead6 # v1.12.3
+        uses: cargo-bins/cargo-binstall@5cbf019d8cb9b9d5b086218c41458ea35d817691 # v1.12.5
         with:
           tool: cargo-fuzz@0.11.2
       - name: "Install cargo-fuzz"
@@ -459,8 +459,8 @@ jobs:
       - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
         with:
           persist-credentials: false
-      - uses: astral-sh/setup-uv@d4b2f3b6ecc6e67c4457f6d3e41ec42d3d0fcb86 # v5.4.2
-      - uses: actions/download-artifact@95815c38cf2ff2164869cbab79da8d1f422bc89e # v4.2.1
+      - uses: astral-sh/setup-uv@6b9c6063abd6010835644d4c2e1bef4cf5cd0fca # v6.0.1
+      - uses: actions/download-artifact@d3f86a106a0bac45b974a628896c90dbdf5c8093 # v4.3.0
         name: Download Ruff binary to test
         id: download-cached-binary
         with:
@@ -504,12 +504,10 @@ jobs:
       # Verify that adding a plugin or rule produces clean code.
       - run: ./scripts/add_rule.py --name DoTheThing --prefix F --code 999 --linter pyflakes
       - run: cargo check
-      - run: cargo fmt --all --check
       - run: |
           ./scripts/add_plugin.py test --url https://pypi.org/project/-test/0.1.0/ --prefix TST
           ./scripts/add_rule.py --name FirstRule --prefix TST --code 001 --linter test
       - run: cargo check
-      - run: cargo fmt --all --check
 
   ecosystem:
     name: "ecosystem"
@@ -525,11 +523,11 @@ jobs:
       - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
         with:
           persist-credentials: false
-      - uses: actions/setup-python@8d9ed9ac5c53483de85588cdf95a591a75ab9f55 # v5.5.0
+      - uses: actions/setup-python@a26af69be951a213d495a4c3e4e4022e16d87065 # v5.6.0
         with:
           python-version: ${{ env.PYTHON_VERSION }}
 
-      - uses: actions/download-artifact@95815c38cf2ff2164869cbab79da8d1f422bc89e # v4.2.1
+      - uses: actions/download-artifact@d3f86a106a0bac45b974a628896c90dbdf5c8093 # v4.3.0
         name: Download comparison Ruff binary
         id: ruff-target
         with:
@@ -636,50 +634,50 @@ jobs:
           name: ecosystem-result
           path: ecosystem-result
 
-  fuzz-redknot:
-    name: "Fuzz for new red-knot panics"
+  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.red_knot == 'true' }}
+    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@95815c38cf2ff2164869cbab79da8d1f422bc89e # v4.2.1
-        name: Download new red-knot binary
-        id: redknot-new
+      - uses: actions/download-artifact@d3f86a106a0bac45b974a628896c90dbdf5c8093 # v4.3.0
+        name: Download new ty binary
+        id: ty-new
         with:
-          name: red_knot
+          name: ty
           path: target/debug
       - uses: dawidd6/action-download-artifact@20319c5641d495c8a52e688b7dc5fada6c3a9fbc # v8
-        name: Download baseline red-knot binary
+        name: Download baseline ty binary
         with:
-          name: red_knot
+          name: ty
           branch: ${{ github.event.pull_request.base.ref }}
           workflow: "ci.yaml"
           check_artifacts: true
-      - uses: astral-sh/setup-uv@d4b2f3b6ecc6e67c4457f6d3e41ec42d3d0fcb86 # v5.4.2
+      - uses: astral-sh/setup-uv@6b9c6063abd6010835644d4c2e1bef4cf5cd0fca # v6.0.1
       - name: Fuzz
         env:
           FORCE_COLOR: 1
-          NEW_REDKNOT: ${{ steps.redknot-new.outputs.download-path }}
+          NEW_TY: ${{ steps.ty-new.outputs.download-path }}
         run: |
           # Make executable, since artifact download doesn't preserve this
-          chmod +x "${PWD}/red_knot" "${NEW_REDKNOT}/red_knot"
+          chmod +x "${PWD}/ty" "${NEW_TY}/ty"
 
           (
             uvx \
             --python="${PYTHON_VERSION}" \
             --from=./python/py-fuzzer \
             fuzz \
-            --test-executable="${NEW_REDKNOT}/red_knot" \
-            --baseline-executable="${PWD}/red_knot" \
+            --test-executable="${NEW_TY}/ty" \
+            --baseline-executable="${PWD}/ty" \
             --only-new-bugs \
-            --bin=red_knot \
+            --bin=ty \
             0-500
           )
 
@@ -692,7 +690,7 @@ jobs:
       - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
         with:
           persist-credentials: false
-      - uses: cargo-bins/cargo-binstall@63aaa5c1932cebabc34eceda9d92a70215dcead6 # v1.12.3
+      - uses: cargo-bins/cargo-binstall@5cbf019d8cb9b9d5b086218c41458ea35d817691 # v1.12.5
       - run: cargo binstall --no-confirm cargo-shear
       - run: cargo shear
 
@@ -705,7 +703,7 @@ jobs:
       - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
         with:
           persist-credentials: false
-      - uses: actions/setup-python@8d9ed9ac5c53483de85588cdf95a591a75ab9f55 # v5.5.0
+      - uses: actions/setup-python@a26af69be951a213d495a4c3e4e4022e16d87065 # v5.6.0
         with:
           python-version: ${{ env.PYTHON_VERSION }}
           architecture: x64
@@ -732,7 +730,11 @@ jobs:
       - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
         with:
           persist-credentials: false
-      - uses: astral-sh/setup-uv@d4b2f3b6ecc6e67c4457f6d3e41ec42d3d0fcb86 # v5.4.2
+      - uses: astral-sh/setup-uv@6b9c6063abd6010835644d4c2e1bef4cf5cd0fca # v6.0.1
+      - uses: Swatinem/rust-cache@9d47c6ad4b02e050fd481d890b2ea34778fd09d6 # v2.7.8
+      - uses: actions/setup-node@49933ea5288caeca8642d1e84afbd3f7d6820020 # v4.4.0
+        with:
+          node-version: 22
       - name: "Cache pre-commit"
         uses: actions/cache@5a3ec84eff668545956fd18022155c47e93e2684 # v4.2.3
         with:
@@ -759,7 +761,7 @@ jobs:
       - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
         with:
           persist-credentials: false
-      - uses: actions/setup-python@8d9ed9ac5c53483de85588cdf95a591a75ab9f55 # v5.5.0
+      - uses: actions/setup-python@a26af69be951a213d495a4c3e4e4022e16d87065 # v5.6.0
         with:
           python-version: "3.13"
       - uses: Swatinem/rust-cache@9d47c6ad4b02e050fd481d890b2ea34778fd09d6 # v2.7.8
@@ -771,7 +773,7 @@ jobs:
       - name: "Install Rust toolchain"
         run: rustup show
       - name: Install uv
-        uses: astral-sh/setup-uv@d4b2f3b6ecc6e67c4457f6d3e41ec42d3d0fcb86 # v5.4.2
+        uses: astral-sh/setup-uv@6b9c6063abd6010835644d4c2e1bef4cf5cd0fca # v6.0.1
       - name: "Install Insiders dependencies"
         if: ${{ env.MKDOCS_INSIDERS_SSH_KEY_EXISTS == 'true' }}
         run: uv pip install -r docs/requirements-insiders.txt --system
@@ -820,7 +822,7 @@ jobs:
       - determine_changes
     if: ${{ !contains(github.event.pull_request.labels.*.name, 'no-test') && (needs.determine_changes.outputs.code == 'true' || github.ref == 'refs/heads/main') }}
     steps:
-      - uses: extractions/setup-just@dd310ad5a97d8e7b41793f8ef055398d51ad4de6 # v2
+      - uses: extractions/setup-just@e33e0265a09d6d736e2ee1e0eb685ef1de4669ff # v3.0.0
         env:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
 
@@ -830,12 +832,12 @@ jobs:
           persist-credentials: false
           repository: "astral-sh/ruff-lsp"
 
-      - uses: actions/setup-python@8d9ed9ac5c53483de85588cdf95a591a75ab9f55 # v5.5.0
+      - uses: actions/setup-python@a26af69be951a213d495a4c3e4e4022e16d87065 # v5.6.0
         with:
           # installation fails on 3.13 and newer
           python-version: "3.12"
 
-      - uses: actions/download-artifact@95815c38cf2ff2164869cbab79da8d1f422bc89e # v4.2.1
+      - uses: actions/download-artifact@d3f86a106a0bac45b974a628896c90dbdf5c8093 # v4.3.0
         name: Download development ruff binary
         id: ruff-target
         with:
@@ -908,7 +910,7 @@ jobs:
         run: rustup show
 
       - name: "Install codspeed"
-        uses: taiki-e/install-action@ab3728c7ba6948b9b429627f4d55a68842b27f18 # v2
+        uses: taiki-e/install-action@941e8a4d9d7cdb696bd4f017cf54aca281f8ffff # v2.51.2
         with:
           tool: cargo-codspeed
 

.github/workflows/daily_fuzz.yaml

@@ -34,7 +34,7 @@ jobs:
       - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
         with:
           persist-credentials: false
-      - uses: astral-sh/setup-uv@d4b2f3b6ecc6e67c4457f6d3e41ec42d3d0fcb86 # v5.4.2
+      - uses: astral-sh/setup-uv@6b9c6063abd6010835644d4c2e1bef4cf5cd0fca # v6.0.1
       - name: "Install Rust toolchain"
         run: rustup show
       - name: "Install mold"

.github/workflows/daily_property_tests.yaml

@@ -1,72 +0,0 @@
-name: Daily property test run
-
-on:
-  workflow_dispatch:
-  schedule:
-    - cron: "0 12 * * *"
-  pull_request:
-    paths:
-      - ".github/workflows/daily_property_tests.yaml"
-
-permissions:
-  contents: read
-
-concurrency:
-  group: ${{ github.workflow }}-${{ github.head_ref || github.run_id }}
-  cancel-in-progress: true
-
-env:
-  CARGO_INCREMENTAL: 0
-  CARGO_NET_RETRY: 10
-  CARGO_TERM_COLOR: always
-  RUSTUP_MAX_RETRIES: 10
-  FORCE_COLOR: 1
-
-jobs:
-  property_tests:
-    name: Property tests
-    runs-on: ubuntu-latest
-    timeout-minutes: 20
-    # Don't run the cron job on forks:
-    if: ${{ github.repository == 'astral-sh/ruff' || github.event_name != 'schedule' }}
-    steps:
-      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
-        with:
-          persist-credentials: false
-      - name: "Install Rust toolchain"
-        run: rustup show
-      - name: "Install mold"
-        uses: rui314/setup-mold@e16410e7f8d9e167b74ad5697a9089a35126eb50 # v1
-      - uses: Swatinem/rust-cache@9d47c6ad4b02e050fd481d890b2ea34778fd09d6 # v2.7.8
-      - name: Build Red Knot
-        # A release build takes longer (2 min vs 1 min), but the property tests run much faster in release
-        # mode (1.5 min vs 14 min), so the overall time is shorter with a release build.
-        run: cargo build --locked --release --package red_knot_python_semantic --tests
-      - name: Run property tests
-        shell: bash
-        run: |
-          export QUICKCHECK_TESTS=100000
-          for _ in {1..5}; do
-            cargo test --locked --release --package red_knot_python_semantic -- --ignored list::property_tests
-            cargo test --locked --release --package red_knot_python_semantic -- --ignored types::property_tests::stable
-          done
-
-  create-issue-on-failure:
-    name: Create an issue if the daily property test run surfaced any bugs
-    runs-on: ubuntu-latest
-    needs: property_tests
-    if: ${{ github.repository == 'astral-sh/ruff' && always() && github.event_name == 'schedule' && needs.property_tests.result == 'failure' }}
-    permissions:
-      issues: write
-    steps:
-      - uses: actions/github-script@60a0d83039c74a4aee543508d2ffcb1c3799cdea # v7.0.1
-        with:
-          github-token: ${{ secrets.GITHUB_TOKEN }}
-          script: |
-            await github.rest.issues.create({
-              owner: "astral-sh",
-              repo: "ruff",
-              title: `Daily property test run failed on ${new Date().toDateString()}`,
-              body: "Run listed here: https://github.com/${{ github.repository }}/actions/runs/${{ github.run_id }}",
-              labels: ["bug", "red-knot", "testing"],
-            })

.github/workflows/mypy_primer.yaml

@@ -5,12 +5,13 @@ permissions: {}
 on:
   pull_request:
     paths:
-      - "crates/red_knot*/**"
+      - "crates/ty*/**"
       - "crates/ruff_db"
       - "crates/ruff_python_ast"
       - "crates/ruff_python_parser"
       - ".github/workflows/mypy_primer.yaml"
       - ".github/workflows/mypy_primer_comment.yaml"
+      - "Cargo.lock"
 
 concurrency:
   group: ${{ github.workflow }}-${{ github.ref_name }}-${{ github.event.pull_request.number || github.sha }}
@@ -36,7 +37,7 @@ jobs:
           persist-credentials: false
 
       - name: Install the latest version of uv
-        uses: astral-sh/setup-uv@d4b2f3b6ecc6e67c4457f6d3e41ec42d3d0fcb86 # v5.4.2
+        uses: astral-sh/setup-uv@6b9c6063abd6010835644d4c2e1bef4cf5cd0fca # v6.0.1
 
       - uses: Swatinem/rust-cache@9d47c6ad4b02e050fd481d890b2ea34778fd09d6 # v2.7.8
         with:
@@ -50,7 +51,11 @@ jobs:
         run: |
           cd ruff
 
-          PRIMER_SELECTOR="$(paste -s -d'|' crates/red_knot_python_semantic/resources/primer/good.txt)"
+          echo "Enabling mypy primer specific configuration overloads (see .github/mypy-primer-ty.toml)"
+          mkdir -p ~/.config/ty
+          cp .github/mypy-primer-ty.toml ~/.config/ty/ty.toml
+
+          PRIMER_SELECTOR="$(paste -s -d'|' crates/ty_python_semantic/resources/primer/good.txt)"
 
           echo "new commit"
           git rev-list --format=%s --max-count=1 "$GITHUB_SHA"
@@ -65,10 +70,10 @@ jobs:
           echo "Project selector: $PRIMER_SELECTOR"
           # Allow the exit code to be 0 or 1, only fail for actual mypy_primer crashes/bugs
           uvx \
-            --from="git+https://github.com/hauntsaninja/mypy_primer@b83b9eade0b7ed2f4b9b129b163acac1ecb48f71" \
+            --from="git+https://github.com/hauntsaninja/mypy_primer@01a7ca325f674433c58e02416a867178d1571128" \
             mypy_primer \
             --repo ruff \
-            --type-checker knot \
+            --type-checker ty \
             --old base_commit \
             --new "$GITHUB_SHA" \
             --project-selector "/($PRIMER_SELECTOR)\$" \

.github/workflows/mypy_primer_comment.yaml

@@ -79,7 +79,7 @@ jobs:
           echo 'EOF' >> "$GITHUB_OUTPUT"
 
       - name: Find existing comment
-        uses: peter-evans/find-comment@3eae4d37986fb5a8592848f6a574fdf654e61f9e # v3
+        uses: peter-evans/find-comment@3eae4d37986fb5a8592848f6a574fdf654e61f9e # v3.1.0
         if: steps.generate-comment.outcome == 'success'
         id: find-comment
         with:

.github/workflows/pr-comment.yaml

@@ -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@3eae4d37986fb5a8592848f6a574fdf654e61f9e # v3.1.0
         if: steps.generate-comment.outcome == 'success'
         id: find-comment
         with:

.github/workflows/publish-docs.yml

@@ -28,7 +28,7 @@ jobs:
           ref: ${{ inputs.ref }}
           persist-credentials: true
 
-      - uses: actions/setup-python@8d9ed9ac5c53483de85588cdf95a591a75ab9f55 # v5.5.0
+      - uses: actions/setup-python@a26af69be951a213d495a4c3e4e4022e16d87065 # v5.6.0
         with:
           python-version: 3.12
 

.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@95815c38cf2ff2164869cbab79da8d1f422bc89e # v4.2.1
+        uses: astral-sh/setup-uv@6b9c6063abd6010835644d4c2e1bef4cf5cd0fca # v6.0.1
+      - uses: actions/download-artifact@d3f86a106a0bac45b974a628896c90dbdf5c8093 # v4.3.0
         with:
           pattern: wheels-*
           path: wheels

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

@@ -1,5 +1,5 @@
-# Publish the Red Knot playground.
-name: "[Knot Playground] Release"
+# Publish the ty playground.
+name: "[ty Playground] Release"
 
 permissions: {}
 
@@ -7,12 +7,12 @@ on:
   push:
     branches: [main]
     paths:
-      - "crates/red_knot*/**"
+      - "crates/ty*/**"
       - "crates/ruff_db/**"
       - "crates/ruff_python_ast/**"
       - "crates/ruff_python_parser/**"
       - "playground/**"
-      - ".github/workflows/publish-knot-playground.yml"
+      - ".github/workflows/publish-ty-playground.yml"
 
 concurrency:
   group: ${{ github.workflow }}-${{ github.ref_name }}
@@ -45,8 +45,8 @@ jobs:
       - name: "Run TypeScript checks"
         run: npm run check
         working-directory: playground
-      - name: "Build Knot playground"
-        run: npm run build --workspace knot-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' }}
@@ -55,4 +55,4 @@ jobs:
           apiToken: ${{ secrets.CF_API_TOKEN }}
           accountId: ${{ secrets.CF_ACCOUNT_ID }}
           # `github.head_ref` is only set during pull requests and for manual runs or tags we use `main` to deploy to production
-          command: pages deploy playground/knot/dist --project-name=knot-playground --branch ${{ github.head_ref || 'main' }} --commit-hash ${GITHUB_SHA}
+          command: pages deploy playground/ty/dist --project-name=ty-playground --branch ${{ github.head_ref || 'main' }} --commit-hash ${GITHUB_SHA}

.github/workflows/release.yml

@@ -69,7 +69,7 @@ jobs:
         # we specify bash to get pipefail; it guards against the `curl` command
         # failing. otherwise `sh` won't catch that `curl` returned non-0
         shell: bash
-        run: "curl --proto '=https' --tlsv1.2 -LsSf https://github.com/astral-sh/cargo-dist/releases/download/v0.28.4/cargo-dist-installer.sh | sh"
+        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"
       - name: Cache dist
         uses: actions/upload-artifact@6027e3dd177782cd8ab9af838c04fd81a07f1d47
         with:

.github/workflows/sync_typeshed.yaml

@@ -39,13 +39,13 @@ jobs:
       - name: Sync typeshed
         id: sync
         run: |
-          rm -rf ruff/crates/red_knot_vendored/vendor/typeshed
-          mkdir ruff/crates/red_knot_vendored/vendor/typeshed
-          cp typeshed/README.md ruff/crates/red_knot_vendored/vendor/typeshed
-          cp typeshed/LICENSE ruff/crates/red_knot_vendored/vendor/typeshed
-          cp -r typeshed/stdlib ruff/crates/red_knot_vendored/vendor/typeshed/stdlib
-          rm -rf ruff/crates/red_knot_vendored/vendor/typeshed/stdlib/@tests
-          git -C typeshed rev-parse HEAD > ruff/crates/red_knot_vendored/vendor/typeshed/source_commit.txt
+          rm -rf ruff/crates/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
       - name: Commit the changes
         id: commit
         if: ${{ steps.sync.outcome == 'success' }}
@@ -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", "red-knot"],
+              labels: ["bug", "ty"],
             })

.markdownlint.yaml

@@ -29,3 +29,7 @@ MD024:
 #
 # Ref: https://github.com/astral-sh/ruff/pull/15011#issuecomment-2544790854
 MD046: false
+
+# Link text should be descriptive
+# Disallows link text like *here* which is annoying.
+MD059: false

.pre-commit-config.yaml

@@ -3,8 +3,9 @@ fail_fast: false
 exclude: |
   (?x)^(
     .github/workflows/release.yml|
-    crates/red_knot_vendored/vendor/.*|
-    crates/red_knot_project/resources/.*|
+    crates/ty_vendored/vendor/.*|
+    crates/ty_project/resources/.*|
+    crates/ty/docs/(configuration|rules|cli).md|
     crates/ruff_benchmark/resources/.*|
     crates/ruff_linter/resources/.*|
     crates/ruff_linter/src/rules/.*/snapshots/.*|
@@ -42,7 +43,7 @@ repos:
           )$
 
   - repo: https://github.com/igorshubovych/markdownlint-cli
-    rev: v0.44.0
+    rev: v0.45.0
     hooks:
       - id: markdownlint-fix
         exclude: |
@@ -65,7 +66,7 @@ repos:
           - black==25.1.0
 
   - repo: https://github.com/crate-ci/typos
-    rev: v1.31.1
+    rev: v1.32.0
     hooks:
       - id: typos
 
@@ -79,7 +80,7 @@ repos:
         pass_filenames: false # This makes it a lot faster
 
   - repo: https://github.com/astral-sh/ruff-pre-commit
-    rev: v0.11.7
+    rev: v0.11.10
     hooks:
       - id: ruff-format
       - id: ruff
@@ -97,7 +98,7 @@ 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: v1.7.0
     hooks:
       - id: zizmor
 

CHANGELOG.md

@@ -1,5 +1,102 @@
 # Changelog
 
+## 0.11.11
+
+### Preview features
+
+- \[`airflow`\] Add autofixes for `AIR302` and `AIR312` ([#17942](https://github.com/astral-sh/ruff/pull/17942))
+- \[`airflow`\] Move rules from `AIR312` to `AIR302` ([#17940](https://github.com/astral-sh/ruff/pull/17940))
+- \[`airflow`\] Update `AIR301` and `AIR311` with the latest Airflow implementations ([#17985](https://github.com/astral-sh/ruff/pull/17985))
+- \[`flake8-simplify`\] Enable fix in preview mode (`SIM117`) ([#18208](https://github.com/astral-sh/ruff/pull/18208))
+
+### Bug fixes
+
+- Fix inconsistent formatting of match-case on `[]` and `_` ([#18147](https://github.com/astral-sh/ruff/pull/18147))
+- \[`pylint`\] Fix `PLW1514` not recognizing the `encoding` positional argument of `codecs.open` ([#18109](https://github.com/astral-sh/ruff/pull/18109))
+
+### CLI
+
+- Add full option name in formatter warning ([#18217](https://github.com/astral-sh/ruff/pull/18217))
+
+### Documentation
+
+- Fix rendering of admonition in docs ([#18163](https://github.com/astral-sh/ruff/pull/18163))
+- \[`flake8-print`\] Improve print/pprint docs for `T201` and `T203` ([#18130](https://github.com/astral-sh/ruff/pull/18130))
+- \[`flake8-simplify`\] Add fix safety section (`SIM110`,`SIM210`) ([#18114](https://github.com/astral-sh/ruff/pull/18114),[#18100](https://github.com/astral-sh/ruff/pull/18100))
+- \[`pylint`\] Fix docs example that produced different output (`PLW0603`) ([#18216](https://github.com/astral-sh/ruff/pull/18216))
+
+## 0.11.10
+
+### Preview features
+
+- \[`ruff`\] Implement a recursive check for `RUF060` ([#17976](https://github.com/astral-sh/ruff/pull/17976))
+- \[`airflow`\] Enable autofixes for `AIR301` and `AIR311` ([#17941](https://github.com/astral-sh/ruff/pull/17941))
+- \[`airflow`\] Apply try catch guard to all `AIR3` rules ([#17887](https://github.com/astral-sh/ruff/pull/17887))
+- \[`airflow`\] Extend `AIR311` rules ([#17913](https://github.com/astral-sh/ruff/pull/17913))
+
+### Bug fixes
+
+- \[`flake8-bugbear`\] Ignore `B028` if `skip_file_prefixes` is present ([#18047](https://github.com/astral-sh/ruff/pull/18047))
+- \[`flake8-pie`\] Mark autofix for `PIE804` as unsafe if the dictionary contains comments ([#18046](https://github.com/astral-sh/ruff/pull/18046))
+- \[`flake8-simplify`\] Correct behavior for `str.split`/`rsplit` with `maxsplit=0` (`SIM905`) ([#18075](https://github.com/astral-sh/ruff/pull/18075))
+- \[`flake8-simplify`\] Fix `SIM905` autofix for `rsplit` creating a reversed list literal ([#18045](https://github.com/astral-sh/ruff/pull/18045))
+- \[`flake8-use-pathlib`\] Suppress diagnostics for all `os.*` functions that have the `dir_fd` parameter (`PTH`) ([#17968](https://github.com/astral-sh/ruff/pull/17968))
+- \[`refurb`\] Mark autofix as safe only for number literals (`FURB116`) ([#17692](https://github.com/astral-sh/ruff/pull/17692))
+
+### Rule changes
+
+- \[`flake8-bandit`\] Skip `S608` for expressionless f-strings ([#17999](https://github.com/astral-sh/ruff/pull/17999))
+- \[`flake8-pytest-style`\] Don't recommend `usefixtures` for `parametrize` values (`PT019`) ([#17650](https://github.com/astral-sh/ruff/pull/17650))
+- \[`pyupgrade`\] Add `resource.error` as deprecated alias of `OSError` (`UP024`) ([#17933](https://github.com/astral-sh/ruff/pull/17933))
+
+### CLI
+
+- Disable jemalloc on Android ([#18033](https://github.com/astral-sh/ruff/pull/18033))
+
+### Documentation
+
+- Update Neovim setup docs ([#18108](https://github.com/astral-sh/ruff/pull/18108))
+- \[`flake8-simplify`\] Add fix safety section (`SIM103`) ([#18086](https://github.com/astral-sh/ruff/pull/18086))
+- \[`flake8-simplify`\] Add fix safety section (`SIM112`) ([#18099](https://github.com/astral-sh/ruff/pull/18099))
+- \[`pylint`\] Add fix safety section (`PLC0414`) ([#17802](https://github.com/astral-sh/ruff/pull/17802))
+- \[`pylint`\] Add fix safety section (`PLE4703`) ([#17824](https://github.com/astral-sh/ruff/pull/17824))
+- \[`pylint`\] Add fix safety section (`PLW1514`) ([#17932](https://github.com/astral-sh/ruff/pull/17932))
+- \[`pylint`\] Add fix safety section (`PLW3301`) ([#17878](https://github.com/astral-sh/ruff/pull/17878))
+- \[`ruff`\] Add fix safety section (`RUF007`) ([#17755](https://github.com/astral-sh/ruff/pull/17755))
+- \[`ruff`\] Add fix safety section (`RUF033`) ([#17760](https://github.com/astral-sh/ruff/pull/17760))
+
+## 0.11.9
+
+### Preview features
+
+- Default to latest supported Python version for version-related syntax errors ([#17529](https://github.com/astral-sh/ruff/pull/17529))
+- Implement deferred annotations for Python 3.14 ([#17658](https://github.com/astral-sh/ruff/pull/17658))
+- \[`airflow`\] Fix `SQLTableCheckOperator` typo (`AIR302`) ([#17946](https://github.com/astral-sh/ruff/pull/17946))
+- \[`airflow`\] Remove `airflow.utils.dag_parsing_context.get_parsing_context` (`AIR301`) ([#17852](https://github.com/astral-sh/ruff/pull/17852))
+- \[`airflow`\] Skip attribute check in try catch block (`AIR301`) ([#17790](https://github.com/astral-sh/ruff/pull/17790))
+- \[`flake8-bandit`\] Mark tuples of string literals as trusted input in `S603` ([#17801](https://github.com/astral-sh/ruff/pull/17801))
+- \[`isort`\] Check full module path against project root(s) when categorizing first-party imports ([#16565](https://github.com/astral-sh/ruff/pull/16565))
+- \[`ruff`\] Add new rule `in-empty-collection` (`RUF060`) ([#16480](https://github.com/astral-sh/ruff/pull/16480))
+
+### Bug fixes
+
+- Fix missing `combine` call for `lint.typing-extensions` setting ([#17823](https://github.com/astral-sh/ruff/pull/17823))
+- \[`flake8-async`\] Fix module name in `ASYNC110`, `ASYNC115`, and `ASYNC116` fixes ([#17774](https://github.com/astral-sh/ruff/pull/17774))
+- \[`pyupgrade`\] Add spaces between tokens as necessary to avoid syntax errors in `UP018` autofix ([#17648](https://github.com/astral-sh/ruff/pull/17648))
+- \[`refurb`\] Fix false positive for float and complex numbers in `FURB116` ([#17661](https://github.com/astral-sh/ruff/pull/17661))
+- [parser] Flag single unparenthesized generator expr with trailing comma in arguments. ([#17893](https://github.com/astral-sh/ruff/pull/17893))
+
+### Documentation
+
+- Add instructions on how to upgrade to a newer Rust version ([#17928](https://github.com/astral-sh/ruff/pull/17928))
+- Update code of conduct email address ([#17875](https://github.com/astral-sh/ruff/pull/17875))
+- Add fix safety sections to `PLC2801`, `PLR1722`, and `RUF013` ([#17825](https://github.com/astral-sh/ruff/pull/17825), [#17826](https://github.com/astral-sh/ruff/pull/17826), [#17759](https://github.com/astral-sh/ruff/pull/17759))
+- Add link to `check-typed-exception` from `S110` and `S112` ([#17786](https://github.com/astral-sh/ruff/pull/17786))
+
+### Other changes
+
+- Allow passing a virtual environment to `ruff analyze graph` ([#17743](https://github.com/astral-sh/ruff/pull/17743))
+
 ## 0.11.8
 
 ### Preview features

CODE_OF_CONDUCT.md

@@ -71,8 +71,7 @@ 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
-<charlie.r.marsh@gmail.com>.
+reported to the community leaders responsible for enforcement at <hey@astral.sh>.
 All complaints will be reviewed and investigated promptly and fairly.
 
 All community leaders are obligated to respect the privacy and security of the

CONTRIBUTING.md

@@ -2,6 +2,11 @@
 
 Welcome! We're happy to have you here. Thank you in advance for your contribution to Ruff.
 
+> [!NOTE]
+>
+> This guide is for Ruff. If you're looking to contribute to ty, please see [the ty contributing
+> guide](https://github.com/astral-sh/ruff/blob/main/crates/ty/CONTRIBUTING.md).
+
 ## The Basics
 
 Ruff welcomes contributions in the form of pull requests.
@@ -366,6 +371,15 @@ 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:
@@ -397,7 +411,7 @@ cargo install hyperfine
 To benchmark the release build:
 
 ```shell
-cargo build --release && hyperfine --warmup 10 \
+cargo build --release --bin ruff && hyperfine --warmup 10 \
   "./target/release/ruff check ./crates/ruff_linter/resources/test/cpython/ --no-cache -e" \
   "./target/release/ruff check ./crates/ruff_linter/resources/test/cpython/ -e"
 
@@ -596,8 +610,7 @@ Then convert the recorded profile
 perf script -F +pid > /tmp/test.perf
 ```
 
-You can now view the converted file with [firefox profiler](https://profiler.firefox.com/), with a
-more in-depth guide [here](https://profiler.firefox.com/docs/#/./guide-perf-profiling)
+You can now view the converted file with [firefox profiler](https://profiler.firefox.com/). To learn more about Firefox profiler, read the [Firefox profiler profiling-guide](https://profiler.firefox.com/docs/#/./guide-perf-profiling).
 
 An alternative is to convert the perf data to `flamegraph.svg` using
 [flamegraph](https://github.com/flamegraph-rs/flamegraph) (`cargo install flamegraph`):

Cargo.toml

@@ -3,8 +3,9 @@ members = ["crates/*"]
 resolver = "2"
 
 [workspace.package]
-edition = "2021"
-rust-version = "1.84"
+# Please update rustfmt.toml when bumping the Rust edition
+edition = "2024"
+rust-version = "1.85"
 homepage = "https://docs.astral.sh/ruff"
 documentation = "https://docs.astral.sh/ruff"
 repository = "https://github.com/astral-sh/ruff"
@@ -23,6 +24,7 @@ ruff_index = { path = "crates/ruff_index" }
 ruff_linter = { path = "crates/ruff_linter" }
 ruff_macros = { path = "crates/ruff_macros" }
 ruff_notebook = { path = "crates/ruff_notebook" }
+ruff_options_metadata = { path = "crates/ruff_options_metadata" }
 ruff_python_ast = { path = "crates/ruff_python_ast" }
 ruff_python_codegen = { path = "crates/ruff_python_codegen" }
 ruff_python_formatter = { path = "crates/ruff_python_formatter" }
@@ -35,14 +37,15 @@ ruff_python_trivia = { path = "crates/ruff_python_trivia" }
 ruff_server = { path = "crates/ruff_server" }
 ruff_source_file = { path = "crates/ruff_source_file" }
 ruff_text_size = { path = "crates/ruff_text_size" }
-red_knot_vendored = { path = "crates/red_knot_vendored" }
 ruff_workspace = { path = "crates/ruff_workspace" }
 
-red_knot_ide = { path = "crates/red_knot_ide" }
-red_knot_project = { path = "crates/red_knot_project", default-features = false }
-red_knot_python_semantic = { path = "crates/red_knot_python_semantic" }
-red_knot_server = { path = "crates/red_knot_server" }
-red_knot_test = { path = "crates/red_knot_test" }
+ty = { path = "crates/ty" }
+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" }
 
 aho-corasick = { version = "1.1.3" }
 anstream = { version = "0.6.18" }
@@ -50,7 +53,7 @@ anstyle = { version = "1.0.10" }
 anyhow = { version = "1.0.80" }
 assert_fs = { version = "1.1.0" }
 argfile = { version = "0.2.0" }
-bincode = { version = "1.3.3" }
+bincode = { version = "2.0.0" }
 bitflags = { version = "2.5.0" }
 bstr = { version = "1.9.1" }
 cachedir = { version = "0.3.1" }
@@ -64,7 +67,7 @@ console_error_panic_hook = { version = "0.1.7" }
 console_log = { version = "1.0.0" }
 countme = { version = "3.0.1" }
 compact_str = "0.9.0"
-criterion = { version = "0.5.1", default-features = false }
+criterion = { version = "0.6.0", default-features = false }
 crossbeam = { version = "0.8.4" }
 dashmap = { version = "6.0.1" }
 dir-test = { version = "0.4.0" }
@@ -83,6 +86,7 @@ hashbrown = { version = "0.15.0", default-features = false, features = [
     "equivalent",
     "inline-more",
 ] }
+heck = "0.5.0"
 ignore = { version = "0.4.22" }
 imara-diff = { version = "0.1.5" }
 imperative = { version = "1.0.4" }
@@ -96,7 +100,7 @@ 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" }
+jod-thread = { version = "1.0.0" }
 libc = { version = "0.2.153" }
 libcst = { version = "1.1.0", default-features = false }
 log = { version = "0.4.17" }
@@ -123,8 +127,9 @@ rand = { version = "0.9.0" }
 rayon = { version = "1.10.0" }
 regex = { version = "1.10.2" }
 rustc-hash = { version = "2.0.0" }
+rustc-stable-hash = { version = "0.1.2" }
 # When updating salsa, make sure to also update the revision in `fuzz/Cargo.toml`
-salsa = { git = "https://github.com/salsa-rs/salsa.git", rev = "42f15835c0005c4b37aaf5bc1a15e3e1b3df14b7" }
+salsa = { git = "https://github.com/salsa-rs/salsa.git", rev = "4818b15f3b7516555d39f5a41cb75970448bee4c" }
 schemars = { version = "0.8.16" }
 seahash = { version = "4.1.0" }
 serde = { version = "1.0.197", features = ["derive"] }
@@ -159,8 +164,9 @@ tracing-log = { version = "0.2.0" }
 tracing-subscriber = { version = "0.3.18", default-features = false, features = [
     "env-filter",
     "fmt",
+    "ansi",
+    "smallvec"
 ] }
-tracing-tree = { version = "0.4.0" }
 tryfn = { version = "0.2.1" }
 typed-arena = { version = "2.0.2" }
 unic-ucd-category = { version = "0.9" }
@@ -182,7 +188,7 @@ wild = { version = "2" }
 zip = { version = "0.6.6", default-features = false }
 
 [workspace.metadata.cargo-shear]
-ignored = ["getrandom"]
+ignored = ["getrandom", "ruff_options_metadata"]
 
 
 [workspace.lints.rust]
@@ -210,6 +216,7 @@ 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.
+unnecessary_debug_formatting = "allow"  # too many instances, the display also doesn't quote the path which is often desired in logs where we use them the most often.
 # Without the hashes we run into a `rustfmt` bug in some snapshot tests, see #13250
 needless_raw_string_hashes = "allow"
 # Disallowed restriction lints
@@ -254,6 +261,9 @@ opt-level = 3
 [profile.dev.package.similar]
 opt-level = 3
 
+[profile.dev.package.salsa]
+opt-level = 3
+
 # Reduce complexity of a parser function that would trigger a locals limit in a wasm tool.
 # https://github.com/bytecodealliance/wasm-tools/blob/b5c3d98e40590512a3b12470ef358d5c7b983b15/crates/wasmparser/src/limits.rs#L29
 [profile.dev.package.ruff_python_parser]
@@ -268,75 +278,3 @@ 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 = "0.28.4"
-# Make distability of apps opt-in instead of opt-out
-dist = false
-# 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 = "plan"
-# 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"]
-
-[workspace.metadata.dist.github-custom-runners]
-global = "depot-ubuntu-latest-4"
-
-[workspace.metadata.dist.github-action-commits]
-"actions/checkout" = "85e6279cec87321a52edac9c87bce653a07cf6c2" # v4
-"actions/upload-artifact" = "6027e3dd177782cd8ab9af838c04fd81a07f1d47" # v4.6.2
-"actions/download-artifact" = "d3f86a106a0bac45b974a628896c90dbdf5c8093" # v4.3.0
-"actions/attest-build-provenance" = "c074443f1aee8d4aeeae555aebba3282517141b2" #v2.2.3

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/0.11.11/install.sh | sh
+powershell -c "irm https://astral.sh/ruff/0.11.11/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: v0.11.11
   hooks:
     # Run the linter.
     - id: ruff
@@ -255,7 +255,7 @@ indent-width = 4
 target-version = "py39"
 
 [lint]
-# Enable Pyflakes (`F`) and a subset of the pycodestyle (`E`)  codes by default.
+# Enable Pyflakes (`F`) and a subset of the pycodestyle (`E`) codes by default.
 select = ["E4", "E7", "E9", "F"]
 ignore = []
 

_typos.toml

@@ -1,7 +1,7 @@
 [files]
 # https://github.com/crate-ci/typos/issues/868
 extend-exclude = [
-    "crates/red_knot_vendored/vendor/**/*",
+    "crates/ty_vendored/vendor/**/*",
     "**/resources/**/*",
     "**/snapshots/**/*",
 ]

clippy.toml

@@ -1,6 +1,7 @@
 doc-valid-idents = [
     "..",
     "CodeQL",
+    "CPython",
     "FastAPI",
     "IPython",
     "LangChain",
@@ -14,7 +15,7 @@ doc-valid-idents = [
     "SNMPv1",
     "SNMPv2",
     "SNMPv3",
-    "PyFlakes"
+    "PyFlakes",
 ]
 
 ignore-interior-mutability = [

crates/red_knot/README.md

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

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

@@ -1,129 +0,0 @@
-# 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: generic protocols
-# revealed: tuple[Literal[ListSubclass], Literal[list], Literal[MutableSequence], Literal[Sequence], Literal[Reversible], Literal[Collection], Literal[Iterable], Literal[Container], @Todo(`Protocol[]` subscript), @Todo(`Generic[]` subscript), Literal[object]]
-reveal_type(ListSubclass.__mro__)
-
-class DictSubclass(typing.Dict): ...
-
-# TODO: generic protocols
-# revealed: tuple[Literal[DictSubclass], Literal[dict], Literal[MutableMapping], Literal[Mapping], Literal[Collection], Literal[Iterable], Literal[Container], @Todo(`Protocol[]` subscript), @Todo(`Generic[]` subscript), Literal[object]]
-reveal_type(DictSubclass.__mro__)
-
-class SetSubclass(typing.Set): ...
-
-# TODO: generic protocols
-# revealed: tuple[Literal[SetSubclass], Literal[set], Literal[MutableSet], Literal[AbstractSet], Literal[Collection], Literal[Iterable], Literal[Container], @Todo(`Protocol[]` subscript), @Todo(`Generic[]` subscript), 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: generic protocols
-# revealed: tuple[Literal[ChainMapSubclass], Literal[ChainMap], Literal[MutableMapping], Literal[Mapping], Literal[Collection], Literal[Iterable], Literal[Container], @Todo(`Protocol[]` subscript), @Todo(`Generic[]` subscript), 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], @Todo(GenericAlias instance), @Todo(`Generic[]` subscript), 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], @Todo(GenericAlias instance), Literal[object]]
-reveal_type(DefaultDictSubclass.__mro__)
-
-class DequeSubclass(typing.Deque): ...
-
-# TODO: generic protocols
-# revealed: tuple[Literal[DequeSubclass], Literal[deque], Literal[MutableSequence], Literal[Sequence], Literal[Reversible], Literal[Collection], Literal[Iterable], Literal[Container], @Todo(`Protocol[]` subscript), @Todo(`Generic[]` subscript), 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], @Todo(GenericAlias instance), Literal[object]]
-reveal_type(OrderedDictSubclass.__mro__)
-```

crates/red_knot_python_semantic/resources/mdtest/diagnostics/no_matching_overload.md

@@ -1,14 +0,0 @@
-# No matching overload diagnostics
-
-<!-- snapshot-diagnostics -->
-
-## Calls to overloaded functions
-
-TODO: Note that we do not yet support the `@overload` decorator to define overloaded functions in
-real Python code. We are instead testing a special-cased function where we create an overloaded
-signature internally. Update this to an `@overload` function in the Python snippet itself once we
-can.
-
-```py
-type("Foo", ())  # error: [no-matching-overload]
-```

crates/red_knot_python_semantic/resources/mdtest/exception/except_star.md

@@ -1,66 +0,0 @@
-# `except*`
-
-`except*` is only available in Python 3.11 and later:
-
-```toml
-[environment]
-python-version = "3.11"
-```
-
-## `except*` with `BaseException`
-
-```py
-try:
-    help()
-except* BaseException as e:
-    # TODO: should be `BaseExceptionGroup[BaseException]` --Alex
-    reveal_type(e)  # revealed: BaseExceptionGroup
-```
-
-## `except*` with specific exception
-
-```py
-try:
-    help()
-except* OSError as e:
-    # TODO: more precise would be `ExceptionGroup[OSError]` --Alex
-    # (needs homogeneous tuples + generics)
-    reveal_type(e)  # revealed: BaseExceptionGroup
-```
-
-## `except*` with multiple exceptions
-
-```py
-try:
-    help()
-except* (TypeError, AttributeError) as e:
-    # TODO: more precise would be `ExceptionGroup[TypeError | AttributeError]` --Alex
-    # (needs homogeneous tuples + generics)
-    reveal_type(e)  # revealed: BaseExceptionGroup
-```
-
-## `except*` with mix of `Exception`s and `BaseException`s
-
-```py
-try:
-    help()
-except* (KeyboardInterrupt, AttributeError) as e:
-    # TODO: more precise would be `BaseExceptionGroup[KeyboardInterrupt | AttributeError]` --Alex
-    reveal_type(e)  # revealed: BaseExceptionGroup
-```
-
-## Invalid `except*` handlers
-
-```py
-try:
-    help()
-except* 3 as e:  # error: [invalid-exception-caught]
-    # TODO: Should be `BaseExceptionGroup[Unknown]` --Alex
-    reveal_type(e)  # revealed: BaseExceptionGroup
-
-try:
-    help()
-except* (AttributeError, 42) as e:  # error: [invalid-exception-caught]
-    # TODO: Should be `BaseExceptionGroup[AttributeError | Unknown]` --Alex
-    reveal_type(e)  # revealed: BaseExceptionGroup
-```

crates/red_knot_python_semantic/resources/mdtest/generics/classes.md

@@ -1,337 +0,0 @@
-# Generic classes
-
-```toml
-[environment]
-python-version = "3.13"
-```
-
-## PEP 695 syntax
-
-TODO: Add a `red_knot_extension` function that asserts whether a function or class is generic.
-
-This is a generic class defined using PEP 695 syntax:
-
-```py
-class C[T]: ...
-```
-
-A class that inherits from a generic class, and fills its type parameters with typevars, is generic:
-
-```py
-class D[U](C[U]): ...
-```
-
-A class that inherits from a generic class, but fills its type parameters with concrete types, is
-_not_ generic:
-
-```py
-class E(C[int]): ...
-```
-
-A class that inherits from a generic class, and doesn't fill its type parameters at all, implicitly
-uses the default value for the typevar. In this case, that default type is `Unknown`, so `F`
-inherits from `C[Unknown]` and is not itself generic.
-
-```py
-class F(C): ...
-```
-
-## Legacy syntax
-
-This is a generic class defined using the legacy syntax:
-
-```py
-from typing import Generic, TypeVar
-
-T = TypeVar("T")
-
-class C(Generic[T]): ...
-```
-
-A class that inherits from a generic class, and fills its type parameters with typevars, is generic.
-
-```py
-class D(C[T]): ...
-```
-
-(Examples `E` and `F` from above do not have analogues in the legacy syntax.)
-
-## Specializing generic classes explicitly
-
-The type parameter can be specified explicitly:
-
-```py
-class C[T]:
-    x: T
-
-reveal_type(C[int]())  # revealed: C[int]
-```
-
-The specialization must match the generic types:
-
-```py
-# error: [too-many-positional-arguments] "Too many positional arguments to class `C`: expected 1, got 2"
-reveal_type(C[int, int]())  # revealed: Unknown
-```
-
-If the type variable has an upper bound, the specialized type must satisfy that bound:
-
-```py
-class Bounded[T: int]: ...
-class BoundedByUnion[T: int | str]: ...
-class IntSubclass(int): ...
-
-reveal_type(Bounded[int]())  # revealed: Bounded[int]
-reveal_type(Bounded[IntSubclass]())  # revealed: Bounded[IntSubclass]
-
-# error: [invalid-argument-type] "Argument to this function is incorrect: Expected `int`, found `str`"
-reveal_type(Bounded[str]())  # revealed: Unknown
-
-# error:  [invalid-argument-type] "Argument to this function is incorrect: Expected `int`, found `int | str`"
-reveal_type(Bounded[int | str]())  # revealed: Unknown
-
-reveal_type(BoundedByUnion[int]())  # revealed: BoundedByUnion[int]
-reveal_type(BoundedByUnion[IntSubclass]())  # revealed: BoundedByUnion[IntSubclass]
-reveal_type(BoundedByUnion[str]())  # revealed: BoundedByUnion[str]
-reveal_type(BoundedByUnion[int | str]())  # revealed: BoundedByUnion[int | str]
-```
-
-If the type variable is constrained, the specialized type must satisfy those constraints:
-
-```py
-class Constrained[T: (int, str)]: ...
-
-reveal_type(Constrained[int]())  # revealed: Constrained[int]
-
-# TODO: error: [invalid-argument-type]
-# TODO: revealed: Constrained[Unknown]
-reveal_type(Constrained[IntSubclass]())  # revealed: Constrained[IntSubclass]
-
-reveal_type(Constrained[str]())  # revealed: Constrained[str]
-
-# TODO: error: [invalid-argument-type]
-# TODO: revealed: Unknown
-reveal_type(Constrained[int | str]())  # revealed: Constrained[int | str]
-
-# error: [invalid-argument-type] "Argument to this function is incorrect: Expected `int | str`, found `object`"
-reveal_type(Constrained[object]())  # revealed: Unknown
-```
-
-## Inferring generic class parameters
-
-We can infer the type parameter from a type context:
-
-```py
-class C[T]:
-    x: T
-
-c: C[int] = C()
-# TODO: revealed: C[int]
-reveal_type(c)  # revealed: C[Unknown]
-```
-
-The typevars of a fully specialized generic class should no longer be visible:
-
-```py
-# TODO: revealed: int
-reveal_type(c.x)  # revealed: Unknown
-```
-
-If the type parameter is not specified explicitly, and there are no constraints that let us infer a
-specific type, we infer the typevar's default type:
-
-```py
-class D[T = int]: ...
-
-reveal_type(D())  # revealed: D[int]
-```
-
-If a typevar does not provide a default, we use `Unknown`:
-
-```py
-reveal_type(C())  # revealed: C[Unknown]
-```
-
-## Inferring generic class parameters from constructors
-
-If the type of a constructor parameter is a class typevar, we can use that to infer the type
-parameter. The types inferred from a type context and from a constructor parameter must be
-consistent with each other.
-
-## `__new__` only
-
-```py
-class C[T]:
-    def __new__(cls, x: T) -> "C[T]":
-        return object.__new__(cls)
-
-reveal_type(C(1))  # revealed: C[Literal[1]]
-
-# error: [invalid-assignment] "Object of type `C[Literal["five"]]` is not assignable to `C[int]`"
-wrong_innards: C[int] = C("five")
-```
-
-## `__init__` only
-
-```py
-class C[T]:
-    def __init__(self, x: T) -> None: ...
-
-reveal_type(C(1))  # revealed: C[Literal[1]]
-
-# error: [invalid-assignment] "Object of type `C[Literal["five"]]` is not assignable to `C[int]`"
-wrong_innards: C[int] = C("five")
-```
-
-## Identical `__new__` and `__init__` signatures
-
-```py
-class C[T]:
-    def __new__(cls, x: T) -> "C[T]":
-        return object.__new__(cls)
-
-    def __init__(self, x: T) -> None: ...
-
-reveal_type(C(1))  # revealed: C[Literal[1]]
-
-# error: [invalid-assignment] "Object of type `C[Literal["five"]]` is not assignable to `C[int]`"
-wrong_innards: C[int] = C("five")
-```
-
-## Compatible `__new__` and `__init__` signatures
-
-```py
-class C[T]:
-    def __new__(cls, *args, **kwargs) -> "C[T]":
-        return object.__new__(cls)
-
-    def __init__(self, x: T) -> None: ...
-
-reveal_type(C(1))  # revealed: C[Literal[1]]
-
-# error: [invalid-assignment] "Object of type `C[Literal["five"]]` is not assignable to `C[int]`"
-wrong_innards: C[int] = C("five")
-
-class D[T]:
-    def __new__(cls, x: T) -> "D[T]":
-        return object.__new__(cls)
-
-    def __init__(self, *args, **kwargs) -> None: ...
-
-reveal_type(D(1))  # revealed: D[Literal[1]]
-
-# error: [invalid-assignment] "Object of type `D[Literal["five"]]` is not assignable to `D[int]`"
-wrong_innards: D[int] = D("five")
-```
-
-## `__init__` is itself generic
-
-TODO: These do not currently work yet, because we don't correctly model the nested generic contexts.
-
-```py
-class C[T]:
-    def __init__[S](self, x: T, y: S) -> None: ...
-
-reveal_type(C(1, 1))  # revealed: C[Literal[1]]
-reveal_type(C(1, "string"))  # revealed: C[Literal[1]]
-reveal_type(C(1, True))  # revealed: C[Literal[1]]
-
-# error: [invalid-assignment] "Object of type `C[Literal["five"]]` is not assignable to `C[int]`"
-wrong_innards: C[int] = C("five", 1)
-```
-
-## Generic subclass
-
-When a generic subclass fills its superclass's type parameter with one of its own, the actual types
-propagate through:
-
-```py
-class Base[T]:
-    x: T | None = None
-
-class Sub[U](Base[U]): ...
-
-reveal_type(Base[int].x)  # revealed: int | None
-reveal_type(Sub[int].x)  # revealed: int | None
-```
-
-## Generic methods
-
-Generic classes can contain methods that are themselves generic. The generic methods can refer to
-the typevars of the enclosing generic class, and introduce new (distinct) typevars that are only in
-scope for the method.
-
-```py
-class C[T]:
-    def method[U](self, u: U) -> U:
-        return u
-    # error: [unresolved-reference]
-    def cannot_use_outside_of_method(self, u: U): ...
-
-    # TODO: error
-    def cannot_shadow_class_typevar[T](self, t: T): ...
-
-c: C[int] = C[int]()
-reveal_type(c.method("string"))  # revealed: Literal["string"]
-```
-
-## Cyclic class definitions
-
-### F-bounded quantification
-
-A class can use itself as the type parameter of one of its superclasses. (This is also known as the
-[curiously recurring template pattern][crtp] or [F-bounded quantification][f-bound].)
-
-#### In a stub file
-
-Here, `Sub` is not a generic class, since it fills its superclass's type parameter (with itself).
-
-```pyi
-class Base[T]: ...
-class Sub(Base[Sub]): ...
-
-reveal_type(Sub)  # revealed: Literal[Sub]
-```
-
-#### With string forward references
-
-A similar case can work in a non-stub file, if forward references are stringified:
-
-```py
-class Base[T]: ...
-class Sub(Base["Sub"]): ...
-
-reveal_type(Sub)  # revealed: Literal[Sub]
-```
-
-#### Without string forward references
-
-In a non-stub file, without stringified forward references, this raises a `NameError`:
-
-```py
-class Base[T]: ...
-
-# error: [unresolved-reference]
-class Sub(Base[Sub]): ...
-```
-
-### Cyclic inheritance as a generic parameter
-
-```pyi
-class Derived[T](list[Derived[T]]): ...
-```
-
-### Direct cyclic inheritance
-
-Inheritance that would result in a cyclic MRO is detected as an error.
-
-```py
-# error: [cyclic-class-definition]
-class C[T](C): ...
-
-# error: [cyclic-class-definition]
-class D[T](D[int]): ...
-```
-
-[crtp]: https://en.wikipedia.org/wiki/Curiously_recurring_template_pattern
-[f-bound]: https://en.wikipedia.org/wiki/Bounded_quantification#F-bounded_quantification

crates/red_knot_python_semantic/resources/mdtest/literal/collections/dictionary.md

@@ -1,7 +0,0 @@
-# Dictionaries
-
-## Empty dictionary
-
-```py
-reveal_type({})  # revealed: dict
-```

crates/red_knot_python_semantic/resources/mdtest/literal/collections/list.md

@@ -1,7 +0,0 @@
-# Lists
-
-## Empty list
-
-```py
-reveal_type([])  # revealed: list
-```

crates/red_knot_python_semantic/resources/mdtest/literal/collections/set.md

@@ -1,7 +0,0 @@
-# Sets
-
-## Basic set
-
-```py
-reveal_type({1, 2})  # revealed: set
-```

crates/red_knot_python_semantic/resources/mdtest/mro.md

@@ -1,408 +0,0 @@
-# Method Resolution Order tests
-
-Tests that assert that we can infer the correct type for a class's `__mro__` attribute.
-
-This attribute is rarely accessed directly at runtime. However, it's extremely important for *us* to
-know the precise possible values of a class's Method Resolution Order, or we won't be able to infer
-the correct type of attributes accessed from instances.
-
-For documentation on method resolution orders, see:
-
-- <https://docs.python.org/3/glossary.html#term-method-resolution-order>
-- <https://docs.python.org/3/howto/mro.html#python-2-3-mro>
-
-## No bases
-
-```py
-class C: ...
-
-reveal_type(C.__mro__)  # revealed: tuple[Literal[C], Literal[object]]
-```
-
-## The special case: `object` itself
-
-```py
-reveal_type(object.__mro__)  # revealed: tuple[Literal[object]]
-```
-
-## Explicit inheritance from `object`
-
-```py
-class C(object): ...
-
-reveal_type(C.__mro__)  # revealed: tuple[Literal[C], Literal[object]]
-```
-
-## Explicit inheritance from non-`object` single base
-
-```py
-class A: ...
-class B(A): ...
-
-reveal_type(B.__mro__)  # revealed: tuple[Literal[B], Literal[A], Literal[object]]
-```
-
-## Linearization of multiple bases
-
-```py
-class A: ...
-class B: ...
-class C(A, B): ...
-
-reveal_type(C.__mro__)  # revealed: tuple[Literal[C], Literal[A], Literal[B], Literal[object]]
-```
-
-## Complex diamond inheritance (1)
-
-This is "ex_2" from <https://docs.python.org/3/howto/mro.html#the-end>
-
-```py
-class O: ...
-class X(O): ...
-class Y(O): ...
-class A(X, Y): ...
-class B(Y, X): ...
-
-reveal_type(A.__mro__)  # revealed: tuple[Literal[A], Literal[X], Literal[Y], Literal[O], Literal[object]]
-reveal_type(B.__mro__)  # revealed: tuple[Literal[B], Literal[Y], Literal[X], Literal[O], Literal[object]]
-```
-
-## Complex diamond inheritance (2)
-
-This is "ex_5" from <https://docs.python.org/3/howto/mro.html#the-end>
-
-```py
-class O: ...
-class F(O): ...
-class E(O): ...
-class D(O): ...
-class C(D, F): ...
-class B(D, E): ...
-class A(B, C): ...
-
-# revealed: tuple[Literal[C], Literal[D], Literal[F], Literal[O], Literal[object]]
-reveal_type(C.__mro__)
-# revealed: tuple[Literal[B], Literal[D], Literal[E], Literal[O], Literal[object]]
-reveal_type(B.__mro__)
-# revealed: tuple[Literal[A], Literal[B], Literal[C], Literal[D], Literal[E], Literal[F], Literal[O], Literal[object]]
-reveal_type(A.__mro__)
-```
-
-## Complex diamond inheritance (3)
-
-This is "ex_6" from <https://docs.python.org/3/howto/mro.html#the-end>
-
-```py
-class O: ...
-class F(O): ...
-class E(O): ...
-class D(O): ...
-class C(D, F): ...
-class B(E, D): ...
-class A(B, C): ...
-
-# revealed: tuple[Literal[C], Literal[D], Literal[F], Literal[O], Literal[object]]
-reveal_type(C.__mro__)
-# revealed: tuple[Literal[B], Literal[E], Literal[D], Literal[O], Literal[object]]
-reveal_type(B.__mro__)
-# revealed: tuple[Literal[A], Literal[B], Literal[E], Literal[C], Literal[D], Literal[F], Literal[O], Literal[object]]
-reveal_type(A.__mro__)
-```
-
-## Complex diamond inheritance (4)
-
-This is "ex_9" from <https://docs.python.org/3/howto/mro.html#the-end>
-
-```py
-class O: ...
-class A(O): ...
-class B(O): ...
-class C(O): ...
-class D(O): ...
-class E(O): ...
-class K1(A, B, C): ...
-class K2(D, B, E): ...
-class K3(D, A): ...
-class Z(K1, K2, K3): ...
-
-# revealed: tuple[Literal[K1], Literal[A], Literal[B], Literal[C], Literal[O], Literal[object]]
-reveal_type(K1.__mro__)
-# revealed: tuple[Literal[K2], Literal[D], Literal[B], Literal[E], Literal[O], Literal[object]]
-reveal_type(K2.__mro__)
-# revealed: tuple[Literal[K3], Literal[D], Literal[A], Literal[O], Literal[object]]
-reveal_type(K3.__mro__)
-# revealed: tuple[Literal[Z], Literal[K1], Literal[K2], Literal[K3], Literal[D], Literal[A], Literal[B], Literal[C], Literal[E], Literal[O], Literal[object]]
-reveal_type(Z.__mro__)
-```
-
-## Inheritance from `Unknown`
-
-```py
-from does_not_exist import DoesNotExist  # error: [unresolved-import]
-
-class A(DoesNotExist): ...
-class B: ...
-class C: ...
-class D(A, B, C): ...
-class E(B, C): ...
-class F(E, A): ...
-
-reveal_type(A.__mro__)  # revealed: tuple[Literal[A], Unknown, Literal[object]]
-reveal_type(D.__mro__)  # revealed: tuple[Literal[D], Literal[A], Unknown, Literal[B], Literal[C], Literal[object]]
-reveal_type(E.__mro__)  # revealed: tuple[Literal[E], Literal[B], Literal[C], Literal[object]]
-reveal_type(F.__mro__)  # revealed: tuple[Literal[F], Literal[E], Literal[B], Literal[C], Literal[A], Unknown, Literal[object]]
-```
-
-## `__bases__` lists that cause errors at runtime
-
-If the class's `__bases__` cause an exception to be raised at runtime and therefore the class
-creation to fail, we infer the class's `__mro__` as being `[<class>, Unknown, object]`:
-
-```py
-# error: [inconsistent-mro] "Cannot create a consistent method resolution order (MRO) for class `Foo` with bases list `[<class 'object'>, <class 'int'>]`"
-class Foo(object, int): ...
-
-reveal_type(Foo.__mro__)  # revealed: tuple[Literal[Foo], Unknown, Literal[object]]
-
-class Bar(Foo): ...
-
-reveal_type(Bar.__mro__)  # revealed: tuple[Literal[Bar], Literal[Foo], Unknown, Literal[object]]
-
-# This is the `TypeError` at the bottom of "ex_2"
-# in the examples at <https://docs.python.org/3/howto/mro.html#the-end>
-class O: ...
-class X(O): ...
-class Y(O): ...
-class A(X, Y): ...
-class B(Y, X): ...
-
-reveal_type(A.__mro__)  # revealed: tuple[Literal[A], Literal[X], Literal[Y], Literal[O], Literal[object]]
-reveal_type(B.__mro__)  # revealed: tuple[Literal[B], Literal[Y], Literal[X], Literal[O], Literal[object]]
-
-# error: [inconsistent-mro] "Cannot create a consistent method resolution order (MRO) for class `Z` with bases list `[<class 'A'>, <class 'B'>]`"
-class Z(A, B): ...
-
-reveal_type(Z.__mro__)  # revealed: tuple[Literal[Z], Unknown, Literal[object]]
-
-class AA(Z): ...
-
-reveal_type(AA.__mro__)  # revealed: tuple[Literal[AA], Literal[Z], Unknown, Literal[object]]
-```
-
-## `__bases__` includes a `Union`
-
-We don't support union types in a class's bases; a base must resolve to a single `ClassType`. If we
-find a union type in a class's bases, we infer the class's `__mro__` as being
-`[<class>, Unknown, object]`, the same as for MROs that cause errors at runtime.
-
-```py
-def returns_bool() -> bool:
-    return True
-
-class A: ...
-class B: ...
-
-if returns_bool():
-    x = A
-else:
-    x = B
-
-reveal_type(x)  # revealed: Literal[A, B]
-
-# error: 11 [invalid-base] "Invalid class base with type `Literal[A, B]` (all bases must be a class, `Any`, `Unknown` or `Todo`)"
-class Foo(x): ...
-
-reveal_type(Foo.__mro__)  # revealed: tuple[Literal[Foo], Unknown, Literal[object]]
-```
-
-## `__bases__` includes multiple `Union`s
-
-```py
-def returns_bool() -> bool:
-    return True
-
-class A: ...
-class B: ...
-class C: ...
-class D: ...
-
-if returns_bool():
-    x = A
-else:
-    x = B
-
-if returns_bool():
-    y = C
-else:
-    y = D
-
-reveal_type(x)  # revealed: Literal[A, B]
-reveal_type(y)  # revealed: Literal[C, D]
-
-# error: 11 [invalid-base] "Invalid class base with type `Literal[A, B]` (all bases must be a class, `Any`, `Unknown` or `Todo`)"
-# error: 14 [invalid-base] "Invalid class base with type `Literal[C, D]` (all bases must be a class, `Any`, `Unknown` or `Todo`)"
-class Foo(x, y): ...
-
-reveal_type(Foo.__mro__)  # revealed: tuple[Literal[Foo], Unknown, Literal[object]]
-```
-
-## `__bases__` lists that cause errors... now with `Union`s
-
-```py
-def returns_bool() -> bool:
-    return True
-
-class O: ...
-class X(O): ...
-class Y(O): ...
-
-if returns_bool():
-    foo = Y
-else:
-    foo = object
-
-# error: 21 [invalid-base] "Invalid class base with type `Literal[Y, object]` (all bases must be a class, `Any`, `Unknown` or `Todo`)"
-class PossibleError(foo, X): ...
-
-reveal_type(PossibleError.__mro__)  # revealed: tuple[Literal[PossibleError], Unknown, Literal[object]]
-
-class A(X, Y): ...
-
-reveal_type(A.__mro__)  # revealed: tuple[Literal[A], Literal[X], Literal[Y], Literal[O], Literal[object]]
-
-if returns_bool():
-    class B(X, Y): ...
-
-else:
-    class B(Y, X): ...
-
-# revealed: tuple[Literal[B], Literal[X], Literal[Y], Literal[O], Literal[object]] | tuple[Literal[B], Literal[Y], Literal[X], Literal[O], Literal[object]]
-reveal_type(B.__mro__)
-
-# error: 12 [invalid-base] "Invalid class base with type `Literal[B, B]` (all bases must be a class, `Any`, `Unknown` or `Todo`)"
-class Z(A, B): ...
-
-reveal_type(Z.__mro__)  # revealed: tuple[Literal[Z], Unknown, Literal[object]]
-```
-
-## `__bases__` lists with duplicate bases
-
-```py
-class Foo(str, str): ...  # error: 16 [duplicate-base] "Duplicate base class `str`"
-
-reveal_type(Foo.__mro__)  # revealed: tuple[Literal[Foo], Unknown, Literal[object]]
-
-class Spam: ...
-class Eggs: ...
-class Ham(
-    Spam,
-    Eggs,
-    Spam,  # error: [duplicate-base] "Duplicate base class `Spam`"
-    Eggs,  # error: [duplicate-base] "Duplicate base class `Eggs`"
-): ...
-
-reveal_type(Ham.__mro__)  # revealed: tuple[Literal[Ham], Unknown, Literal[object]]
-
-class Mushrooms: ...
-class Omelette(Spam, Eggs, Mushrooms, Mushrooms): ...  # error: [duplicate-base]
-
-reveal_type(Omelette.__mro__)  # revealed: tuple[Literal[Omelette], Unknown, Literal[object]]
-```
-
-## `__bases__` lists with duplicate `Unknown` bases
-
-```py
-# error: [unresolved-import]
-# error: [unresolved-import]
-from does_not_exist import unknown_object_1, unknown_object_2
-
-reveal_type(unknown_object_1)  # revealed: Unknown
-reveal_type(unknown_object_2)  # revealed: Unknown
-
-# We *should* emit an error here to warn the user that we have no idea
-# what the MRO of this class should really be.
-# However, we don't complain about "duplicate base classes" here,
-# even though two classes are both inferred as being `Unknown`.
-#
-# (TODO: should we revisit this? Does it violate the gradual guarantee?
-# Should we just silently infer `[Foo, Unknown, object]` as the MRO here
-# without emitting any error at all? Not sure...)
-#
-# error: [inconsistent-mro] "Cannot create a consistent method resolution order (MRO) for class `Foo` with bases list `[Unknown, Unknown]`"
-class Foo(unknown_object_1, unknown_object_2): ...
-
-reveal_type(Foo.__mro__)  # revealed: tuple[Literal[Foo], Unknown, Literal[object]]
-```
-
-## Unrelated objects inferred as `Any`/`Unknown` do not have special `__mro__` attributes
-
-```py
-from does_not_exist import unknown_object  # error: [unresolved-import]
-
-reveal_type(unknown_object)  # revealed: Unknown
-reveal_type(unknown_object.__mro__)  # revealed: Unknown
-```
-
-## Classes that inherit from themselves
-
-These are invalid, but we need to be able to handle them gracefully without panicking.
-
-```pyi
-class Foo(Foo): ...  # error: [cyclic-class-definition]
-
-reveal_type(Foo)  # revealed: Literal[Foo]
-reveal_type(Foo.__mro__)  # revealed: tuple[Literal[Foo], Unknown, Literal[object]]
-
-class Bar: ...
-class Baz: ...
-class Boz(Bar, Baz, Boz): ...  # error: [cyclic-class-definition]
-
-reveal_type(Boz)  # revealed: Literal[Boz]
-reveal_type(Boz.__mro__)  # revealed: tuple[Literal[Boz], Unknown, Literal[object]]
-```
-
-## Classes with indirect cycles in their MROs
-
-These are similarly unlikely, but we still shouldn't crash:
-
-```pyi
-class Foo(Bar): ...  # error: [cyclic-class-definition]
-class Bar(Baz): ...  # error: [cyclic-class-definition]
-class Baz(Foo): ...  # error: [cyclic-class-definition]
-
-reveal_type(Foo.__mro__)  # revealed: tuple[Literal[Foo], Unknown, Literal[object]]
-reveal_type(Bar.__mro__)  # revealed: tuple[Literal[Bar], Unknown, Literal[object]]
-reveal_type(Baz.__mro__)  # revealed: tuple[Literal[Baz], Unknown, Literal[object]]
-```
-
-## Classes with cycles in their MROs, and multiple inheritance
-
-```pyi
-class Spam: ...
-class Foo(Bar): ...  # error: [cyclic-class-definition]
-class Bar(Baz): ...  # error: [cyclic-class-definition]
-class Baz(Foo, Spam): ...  # error: [cyclic-class-definition]
-
-reveal_type(Foo.__mro__)  # revealed: tuple[Literal[Foo], Unknown, Literal[object]]
-reveal_type(Bar.__mro__)  # revealed: tuple[Literal[Bar], Unknown, Literal[object]]
-reveal_type(Baz.__mro__)  # revealed: tuple[Literal[Baz], Unknown, Literal[object]]
-```
-
-## Classes with cycles in their MRO, and a sub-graph
-
-```pyi
-class FooCycle(BarCycle): ...  # error: [cyclic-class-definition]
-class Foo: ...
-class BarCycle(FooCycle): ...  # error: [cyclic-class-definition]
-class Bar(Foo): ...
-
-# Avoid emitting the errors for these. The classes have cyclic superclasses,
-# but are not themselves cyclic...
-class Baz(Bar, BarCycle): ...
-class Spam(Baz): ...
-
-reveal_type(FooCycle.__mro__)  # revealed: tuple[Literal[FooCycle], Unknown, Literal[object]]
-reveal_type(BarCycle.__mro__)  # revealed: tuple[Literal[BarCycle], Unknown, Literal[object]]
-reveal_type(Baz.__mro__)  # revealed: tuple[Literal[Baz], Unknown, Literal[object]]
-reveal_type(Spam.__mro__)  # revealed: tuple[Literal[Spam], Unknown, Literal[object]]
-```

crates/red_knot_python_semantic/resources/mdtest/narrow/conditionals/nested.md

@@ -1,44 +0,0 @@
-# Narrowing for nested conditionals
-
-## Multiple negative contributions
-
-```py
-def _(x: int):
-    if x != 1:
-        if x != 2:
-            if x != 3:
-                reveal_type(x)  # revealed: int & ~Literal[1] & ~Literal[2] & ~Literal[3]
-```
-
-## Multiple negative contributions with simplification
-
-```py
-def _(flag1: bool, flag2: bool):
-    x = 1 if flag1 else 2 if flag2 else 3
-
-    if x != 1:
-        reveal_type(x)  # revealed: Literal[2, 3]
-        if x != 2:
-            reveal_type(x)  # revealed: Literal[3]
-```
-
-## elif-else blocks
-
-```py
-def _(flag1: bool, flag2: bool):
-    x = 1 if flag1 else 2 if flag2 else 3
-
-    if x != 1:
-        reveal_type(x)  # revealed: Literal[2, 3]
-        if x == 2:
-            reveal_type(x)  # revealed: Literal[2]
-        elif x == 3:
-            reveal_type(x)  # revealed: Literal[3]
-        else:
-            reveal_type(x)  # revealed: Never
-
-    elif x != 2:
-        reveal_type(x)  # revealed: Literal[1]
-    else:
-        reveal_type(x)  # revealed: Never
-```

crates/red_knot_python_semantic/resources/mdtest/scopes/global.md

@@ -1,177 +0,0 @@
-# `global` references
-
-## Implicit global in function
-
-A name reference to a never-defined symbol in a function is implicitly a global lookup.
-
-```py
-x = 1
-
-def f():
-    reveal_type(x)  # revealed: Unknown | Literal[1]
-```
-
-## Explicit global in function
-
-```py
-x = 1
-
-def f():
-    global x
-    reveal_type(x)  # revealed: Unknown | Literal[1]
-```
-
-## Unassignable type in function
-
-```py
-x: int = 1
-
-def f():
-    y: int = 1
-    # error: [invalid-assignment] "Object of type `Literal[""]` is not assignable to `int`"
-    y = ""
-
-    global x
-    # TODO: error: [invalid-assignment] "Object of type `Literal[""]` is not assignable to `int`"
-    x = ""
-```
-
-## Nested intervening scope
-
-A `global` statement causes lookup to skip any bindings in intervening scopes:
-
-```py
-x: int = 1
-
-def outer():
-    x: str = ""
-
-    def inner():
-        global x
-        # TODO: revealed: int
-        reveal_type(x)  # revealed: str
-```
-
-## Narrowing
-
-An assignment following a `global` statement should narrow the type in the local scope after the
-assignment.
-
-```py
-x: int | None
-
-def f():
-    global x
-    x = 1
-    reveal_type(x)  # revealed: Literal[1]
-```
-
-## `nonlocal` and `global`
-
-A binding cannot be both `nonlocal` and `global`. This should emit a semantic syntax error. CPython
-marks the `nonlocal` line, while `mypy`, `pyright`, and `ruff` (`PLE0115`) mark the `global` line.
-
-```py
-x = 1
-
-def f():
-    x = 1
-    def g() -> None:
-        nonlocal x
-        global x  # TODO: error: [invalid-syntax] "name 'x' is nonlocal and global"
-        x = None
-```
-
-## Global declaration after `global` statement
-
-```py
-def f():
-    global x
-    # TODO this should also not be an error
-    y = x  # error: [unresolved-reference] "Name `x` used when not defined"
-    x = 1  # No error.
-
-x = 2
-```
-
-## Semantic syntax errors
-
-Using a name prior to its `global` declaration in the same scope is a syntax error.
-
-```py
-x = 1
-
-def f():
-    print(x)  # TODO: error: [invalid-syntax] name `x` is used prior to global declaration
-    global x
-    print(x)
-
-def f():
-    global x
-    print(x)  # TODO: error: [invalid-syntax] name `x` is used prior to global declaration
-    global x
-    print(x)
-
-def f():
-    print(x)  # TODO: error: [invalid-syntax] name `x` is used prior to global declaration
-    global x, y
-    print(x)
-
-def f():
-    global x, y
-    print(x)  # TODO: error: [invalid-syntax] name `x` is used prior to global declaration
-    global x, y
-    print(x)
-
-def f():
-    x = 1  # TODO: error: [invalid-syntax] name `x` is used prior to global declaration
-    global x
-    x = 1
-
-def f():
-    global x
-    x = 1  # TODO: error: [invalid-syntax] name `x` is used prior to global declaration
-    global x
-    x = 1
-
-def f():
-    del x  # TODO: error: [invalid-syntax] name `x` is used prior to global declaration
-    global x, y
-    del x
-
-def f():
-    global x, y
-    del x  # TODO: error: [invalid-syntax] name `x` is used prior to global declaration
-    global x, y
-    del x
-
-def f():
-    del x  # TODO: error: [invalid-syntax] name `x` is used prior to global declaration
-    global x
-    del x
-
-def f():
-    global x
-    del x  # TODO: error: [invalid-syntax] name `x` is used prior to global declaration
-    global x
-    del x
-
-def f():
-    del x  # TODO: error: [invalid-syntax] name `x` is used prior to global declaration
-    global x, y
-    del x
-
-def f():
-    global x, y
-    del x  # TODO: error: [invalid-syntax] name `x` is used prior to global declaration
-    global x, y
-    del x
-
-def f():
-    print(f"{x=}")  # TODO: error: [invalid-syntax] name `x` is used prior to global declaration
-    global x
-
-# still an error in module scope
-x = None  # TODO: error: [invalid-syntax] name `x` is used prior to global declaration
-global x
-```

crates/red_knot_python_semantic/resources/mdtest/snapshots/basic.md_-_Structures_-_Unresolvable_module_import.snap

@@ -1,28 +0,0 @@
----
-source: crates/red_knot_test/src/lib.rs
-expression: snapshot
----
----
-mdtest name: basic.md - Structures - Unresolvable module import
-mdtest path: crates/red_knot_python_semantic/resources/mdtest/import/basic.md
----
-
-# Python source files
-
-## mdtest_snippet.py
-
-```
-1 | import zqzqzqzqzqzqzq  # error: [unresolved-import] "Cannot resolve import `zqzqzqzqzqzqzq`"
-```
-
-# Diagnostics
-
-```
-error: lint:unresolved-import: Cannot resolve import `zqzqzqzqzqzqzq`
- --> src/mdtest_snippet.py:1:8
-  |
-1 | import zqzqzqzqzqzqzq  # error: [unresolved-import] "Cannot resolve import `zqzqzqzqzqzqzq`"
-  |        ^^^^^^^^^^^^^^
-  |
-
-```

crates/red_knot_python_semantic/resources/mdtest/snapshots/functions.md_-_Generic_functions_-_Inferring_a_bound_typevar.snap

@@ -1,86 +0,0 @@
----
-source: crates/red_knot_test/src/lib.rs
-expression: snapshot
----
----
-mdtest name: functions.md - Generic functions - Inferring a bound typevar
-mdtest path: crates/red_knot_python_semantic/resources/mdtest/generics/functions.md
----
-
-# Python source files
-
-## mdtest_snippet.py
-
-```
-1 | from typing_extensions import reveal_type
-2 | 
-3 | def f[T: int](x: T) -> T:
-4 |     return x
-5 | 
-6 | reveal_type(f(1))  # revealed: Literal[1]
-7 | reveal_type(f(True))  # revealed: Literal[True]
-8 | # error: [invalid-argument-type] "Argument to this function is incorrect: Argument type `Literal["string"]` does not satisfy upper bound of type variable `T`"
-9 | reveal_type(f("string"))  # revealed: Unknown
-```
-
-# Diagnostics
-
-```
-info: revealed-type: Revealed type
- --> src/mdtest_snippet.py:6:1
-  |
-4 |     return x
-5 |
-6 | reveal_type(f(1))  # revealed: Literal[1]
-  | ^^^^^^^^^^^^^^^^^ `Literal[1]`
-7 | reveal_type(f(True))  # revealed: Literal[True]
-8 | # error: [invalid-argument-type] "Argument to this function is incorrect: Argument type `Literal["string"]` does not satisfy upper bo...
-  |
-
-```
-
-```
-info: revealed-type: Revealed type
- --> src/mdtest_snippet.py:7:1
-  |
-6 | reveal_type(f(1))  # revealed: Literal[1]
-7 | reveal_type(f(True))  # revealed: Literal[True]
-  | ^^^^^^^^^^^^^^^^^^^^ `Literal[True]`
-8 | # error: [invalid-argument-type] "Argument to this function is incorrect: Argument type `Literal["string"]` does not satisfy upper b...
-9 | reveal_type(f("string"))  # revealed: Unknown
-  |
-
-```
-
-```
-error: lint:invalid-argument-type: Argument to this function is incorrect
- --> src/mdtest_snippet.py:9:15
-  |
-7 | reveal_type(f(True))  # revealed: Literal[True]
-8 | # error: [invalid-argument-type] "Argument to this function is incorrect: Argument type `Literal["string"]` does not satisfy upper b...
-9 | reveal_type(f("string"))  # revealed: Unknown
-  |               ^^^^^^^^ Argument type `Literal["string"]` does not satisfy upper bound of type variable `T`
-  |
-info: Type variable defined here
- --> src/mdtest_snippet.py:3:7
-  |
-1 | from typing_extensions import reveal_type
-2 |
-3 | def f[T: int](x: T) -> T:
-  |       ^^^^^^
-4 |     return x
-  |
-
-```
-
-```
-info: revealed-type: Revealed type
- --> src/mdtest_snippet.py:9:1
-  |
-7 | reveal_type(f(True))  # revealed: Literal[True]
-8 | # error: [invalid-argument-type] "Argument to this function is incorrect: Argument type `Literal["string"]` does not satisfy upper b...
-9 | reveal_type(f("string"))  # revealed: Unknown
-  | ^^^^^^^^^^^^^^^^^^^^^^^^ `Unknown`
-  |
-
-```

crates/red_knot_python_semantic/resources/mdtest/snapshots/no_matching_overload.md_-_No_matching_overload_diagnostics_-_Calls_to_overloaded_functions.snap

@@ -1,28 +0,0 @@
----
-source: crates/red_knot_test/src/lib.rs
-expression: snapshot
----
----
-mdtest name: no_matching_overload.md - No matching overload diagnostics - Calls to overloaded functions
-mdtest path: crates/red_knot_python_semantic/resources/mdtest/diagnostics/no_matching_overload.md
----
-
-# Python source files
-
-## mdtest_snippet.py
-
-```
-1 | type("Foo", ())  # error: [no-matching-overload]
-```
-
-# Diagnostics
-
-```
-error: lint:no-matching-overload: No overload of class `type` matches arguments
- --> src/mdtest_snippet.py:1:1
-  |
-1 | type("Foo", ())  # error: [no-matching-overload]
-  | ^^^^^^^^^^^^^^^
-  |
-
-```

crates/red_knot_python_semantic/resources/mdtest/suppressions/knot_ignore.md

@@ -1,191 +0,0 @@
-# Suppressing errors with `knot: ignore`
-
-Type check errors can be suppressed by a `knot: ignore` comment on the same line as the violation.
-
-## Simple `knot: ignore`
-
-```py
-a = 4 + test  # knot: ignore
-```
-
-## Suppressing a specific code
-
-```py
-a = 4 + test  # knot: ignore[unresolved-reference]
-```
-
-## Unused suppression
-
-```py
-test = 10
-# error: [unused-ignore-comment] "Unused `knot: ignore` directive: 'possibly-unresolved-reference'"
-a = test + 3  # knot: ignore[possibly-unresolved-reference]
-```
-
-## Unused suppression if the error codes don't match
-
-```py
-# error: [unresolved-reference]
-# error: [unused-ignore-comment] "Unused `knot: ignore` directive: 'possibly-unresolved-reference'"
-a = test + 3  # knot: ignore[possibly-unresolved-reference]
-```
-
-## Suppressed unused comment
-
-```py
-# error: [unused-ignore-comment]
-a = 10 / 2  # knot: ignore[division-by-zero]
-a = 10 / 2  # knot: ignore[division-by-zero, unused-ignore-comment]
-a = 10 / 2  # knot: ignore[unused-ignore-comment, division-by-zero]
-a = 10 / 2  # knot: ignore[unused-ignore-comment] # type: ignore
-a = 10 / 2  # type: ignore # knot: ignore[unused-ignore-comment]
-```
-
-## Unused ignore comment
-
-```py
-# error: [unused-ignore-comment] "Unused `knot: ignore` directive: 'unused-ignore-comment'"
-a = 10 / 0  # knot: ignore[division-by-zero, unused-ignore-comment]
-```
-
-## Multiple unused comments
-
-Today, Red Knot emits a diagnostic for every unused code. We might want to group the codes by
-comment at some point in the future.
-
-```py
-# error: [unused-ignore-comment] "Unused `knot: ignore` directive: 'division-by-zero'"
-# error: [unused-ignore-comment] "Unused `knot: ignore` directive: 'unresolved-reference'"
-a = 10 / 2  # knot: ignore[division-by-zero, unresolved-reference]
-
-# error: [unused-ignore-comment] "Unused `knot: ignore` directive: 'invalid-assignment'"
-# error: [unused-ignore-comment] "Unused `knot: ignore` directive: 'unresolved-reference'"
-a = 10 / 0  # knot: ignore[invalid-assignment, division-by-zero, unresolved-reference]
-```
-
-## Multiple suppressions
-
-```py
-# fmt: off
-def test(a: f"f-string type annotation", b: b"byte-string-type-annotation"): ...  # knot: ignore[fstring-type-annotation, byte-string-type-annotation]
-```
-
-## Can't suppress syntax errors
-
-<!-- blacken-docs:off -->
-
-```py
-# error: [invalid-syntax]
-# error: [unused-ignore-comment]
-def test($):  # knot: ignore
-    pass
-```
-
-<!-- blacken-docs:on -->
-
-## Can't suppress `revealed-type` diagnostics
-
-```py
-a = 10
-# revealed: Literal[10]
-# error: [unknown-rule] "Unknown rule `revealed-type`"
-reveal_type(a)  # knot: ignore[revealed-type]
-```
-
-## Extra whitespace in type ignore comments is allowed
-
-```py
-a = 10 / 0  # knot   :   ignore
-a = 10 / 0  # knot: ignore  [    division-by-zero   ]
-```
-
-## Whitespace is optional
-
-```py
-# fmt: off
-a = 10 / 0  #knot:ignore[division-by-zero]
-```
-
-## Trailing codes comma
-
-Trailing commas in the codes section are allowed:
-
-```py
-a = 10 / 0  # knot: ignore[division-by-zero,]
-```
-
-## Invalid characters in codes
-
-```py
-# error: [division-by-zero]
-# error: [invalid-ignore-comment] "Invalid `knot: ignore` comment: expected a alphanumeric character or `-` or `_` as code"
-a = 10 / 0  # knot: ignore[*-*]
-```
-
-## Trailing whitespace
-
-<!-- blacken-docs:off -->
-
-```py
-a = 10 / 0  # knot: ignore[division-by-zero]      
-            #                               ^^^^^^ trailing whitespace
-```
-
-<!-- blacken-docs:on -->
-
-## Missing comma
-
-A missing comma results in an invalid suppression comment. We may want to recover from this in the
-future.
-
-```py
-# error: [unresolved-reference]
-# error: [invalid-ignore-comment] "Invalid `knot: ignore` comment: expected a comma separating the rule codes"
-a = x / 0  # knot: ignore[division-by-zero unresolved-reference]
-```
-
-## Missing closing bracket
-
-```py
-# error: [unresolved-reference] "Name `x` used when not defined"
-# error: [invalid-ignore-comment] "Invalid `knot: ignore` comment: expected a comma separating the rule codes"
-a = x / 2  # knot: ignore[unresolved-reference
-```
-
-## Empty codes
-
-An empty codes array suppresses no-diagnostics and is always useless
-
-```py
-# error: [division-by-zero]
-# error: [unused-ignore-comment] "Unused `knot: ignore` without a code"
-a = 4 / 0  # knot: ignore[]
-```
-
-## File-level suppression comments
-
-File level suppression comments are currently intentionally unsupported because we've yet to decide
-if they should use a different syntax that also supports enabling rules or changing the rule's
-severity: `knot: possibly-undefined-reference=error`
-
-```py
-# error: [unused-ignore-comment]
-# knot: ignore[division-by-zero]
-
-a = 4 / 0  # error: [division-by-zero]
-```
-
-## Unknown rule
-
-```py
-# error: [unknown-rule] "Unknown rule `is-equal-14`"
-a = 10 + 4  # knot: ignore[is-equal-14]
-```
-
-## Code with `lint:` prefix
-
-```py
-# error:[unknown-rule] "Unknown rule `lint:division-by-zero`. Did you mean `division-by-zero`?"
-# error: [division-by-zero]
-a = 10 / 0  # knot: ignore[lint:division-by-zero]
-```

crates/red_knot_python_semantic/resources/primer/bad.txt

@@ -1,35 +0,0 @@
-Expression  # cycle panic (signature_)
-Tanjun  # cycle panic (signature_)
-aiohttp  # missing expression ID
-alerta  # missing expression ID
-altair  # cycle panics (try_metaclass_)
-antidote  # hangs / slow
-artigraph  # cycle panics (value_type_)
-colour  # cycle panics (try_metaclass_)
-core  # cycle panics (value_type_)
-cpython  # missing expression ID, access to field whilst being initialized, too many cycle iterations
-discord.py  # some kind of hang, only when multi-threaded?
-freqtrade  # cycle panics (try_metaclass_)
-hydpy  # cycle panics (try_metaclass_)
-ibis  # cycle panics (try_metaclass_)
-manticore  # stack overflow
-materialize  # stack overflow
-meson  # missing expression ID
-mypy  # cycle panic (signature_)
-pandas  # slow
-pandas-stubs  # cycle panics (try_metaclass_)
-pandera  # cycle panics (try_metaclass_)
-prefect # slow
-pytest  # cycle panics (signature_), missing expression ID
-pywin32  # bad use-def map (binding with definitely-visible unbound)
-schemathesis  # cycle panics (signature_)
-scikit-learn  # success, but mypy-primer hangs processing the output
-scipy  # missing expression ID
-spack  # success, but mypy-primer hangs processing the output
-spark  # cycle panics (try_metaclass_)
-sphinx  # missing expression ID
-steam.py  # missing expression ID
-streamlit  # cycle panic (signature_)
-sympy  # stack overflow
-trio  # missing expression ID
-xarray  # cycle panics (try_metaclass_)

crates/red_knot_server/src/server/api/requests/diagnostic.rs

@@ -1,106 +0,0 @@
-use std::borrow::Cow;
-
-use lsp_types::request::DocumentDiagnosticRequest;
-use lsp_types::{
-    Diagnostic, DiagnosticSeverity, DocumentDiagnosticParams, DocumentDiagnosticReport,
-    DocumentDiagnosticReportResult, FullDocumentDiagnosticReport, NumberOrString, Range,
-    RelatedFullDocumentDiagnosticReport, Url,
-};
-
-use crate::document::ToRangeExt;
-use crate::server::api::traits::{BackgroundDocumentRequestHandler, RequestHandler};
-use crate::server::{client::Notifier, Result};
-use crate::session::DocumentSnapshot;
-use red_knot_project::{Db, ProjectDatabase};
-use ruff_db::diagnostic::Severity;
-use ruff_db::source::{line_index, source_text};
-
-pub(crate) struct DocumentDiagnosticRequestHandler;
-
-impl RequestHandler for DocumentDiagnosticRequestHandler {
-    type RequestType = DocumentDiagnosticRequest;
-}
-
-impl BackgroundDocumentRequestHandler for DocumentDiagnosticRequestHandler {
-    fn document_url(params: &DocumentDiagnosticParams) -> Cow<Url> {
-        Cow::Borrowed(&params.text_document.uri)
-    }
-
-    fn run_with_snapshot(
-        snapshot: DocumentSnapshot,
-        db: ProjectDatabase,
-        _notifier: Notifier,
-        _params: DocumentDiagnosticParams,
-    ) -> Result<DocumentDiagnosticReportResult> {
-        let diagnostics = compute_diagnostics(&snapshot, &db);
-
-        Ok(DocumentDiagnosticReportResult::Report(
-            DocumentDiagnosticReport::Full(RelatedFullDocumentDiagnosticReport {
-                related_documents: None,
-                full_document_diagnostic_report: FullDocumentDiagnosticReport {
-                    result_id: None,
-                    items: diagnostics,
-                },
-            }),
-        ))
-    }
-}
-
-fn compute_diagnostics(snapshot: &DocumentSnapshot, db: &ProjectDatabase) -> Vec<Diagnostic> {
-    let Some(file) = snapshot.file(db) else {
-        tracing::info!(
-            "No file found for snapshot for `{}`",
-            snapshot.query().file_url()
-        );
-        return vec![];
-    };
-
-    let diagnostics = match db.check_file(file) {
-        Ok(diagnostics) => diagnostics,
-        Err(cancelled) => {
-            tracing::info!("Diagnostics computation {cancelled}");
-            return vec![];
-        }
-    };
-
-    diagnostics
-        .as_slice()
-        .iter()
-        .map(|message| to_lsp_diagnostic(db, message, snapshot.encoding()))
-        .collect()
-}
-
-fn to_lsp_diagnostic(
-    db: &dyn Db,
-    diagnostic: &ruff_db::diagnostic::Diagnostic,
-    encoding: crate::PositionEncoding,
-) -> Diagnostic {
-    let range = if let Some(span) = diagnostic.primary_span() {
-        let index = line_index(db.upcast(), span.file());
-        let source = source_text(db.upcast(), span.file());
-
-        span.range()
-            .map(|range| range.to_lsp_range(&source, &index, encoding))
-            .unwrap_or_default()
-    } else {
-        Range::default()
-    };
-
-    let severity = match diagnostic.severity() {
-        Severity::Info => DiagnosticSeverity::INFORMATION,
-        Severity::Warning => DiagnosticSeverity::WARNING,
-        Severity::Error | Severity::Fatal => DiagnosticSeverity::ERROR,
-    };
-
-    Diagnostic {
-        range,
-        severity: Some(severity),
-        tags: None,
-        code: Some(NumberOrString::String(diagnostic.id().to_string())),
-        code_description: None,
-        source: Some("red-knot".into()),
-        message: diagnostic.concise_message().to_string(),
-        related_information: None,
-        data: None,
-    }
-}

crates/red_knot_vendored/knot_extensions/README.md

@@ -1,3 +0,0 @@
-The `knot_extensions.pyi` file in this directory will be symlinked into
-the `vendor/typeshed/stdlib` directory every time we sync our `typeshed`
-stubs (see `.github/workflows/sync_typeshed.yaml`).

crates/red_knot_vendored/vendor/typeshed/source_commit.txt

@@ -1 +0,0 @@
-eec809d049d10a5ae9b88780eab15fe36a9768d7

crates/red_knot_vendored/vendor/typeshed/stdlib/__main__.pyi

@@ -1,3 +0,0 @@
-from typing import Any
-
-def __getattr__(name: str) -> Any: ...

crates/red_knot_vendored/vendor/typeshed/stdlib/concurrent/futures/thread.pyi

@@ -1,76 +0,0 @@
-import queue
-from collections.abc import Callable, Iterable, Mapping, Set as AbstractSet
-from threading import Lock, Semaphore, Thread
-from types import GenericAlias
-from typing import Any, Generic, TypeVar, overload
-from typing_extensions import TypeVarTuple, Unpack
-from weakref import ref
-
-from ._base import BrokenExecutor, Executor, Future
-
-_Ts = TypeVarTuple("_Ts")
-
-_threads_queues: Mapping[Any, Any]
-_shutdown: bool
-_global_shutdown_lock: Lock
-
-def _python_exit() -> None: ...
-
-_S = TypeVar("_S")
-
-class _WorkItem(Generic[_S]):
-    future: Future[_S]
-    fn: Callable[..., _S]
-    args: Iterable[Any]
-    kwargs: Mapping[str, Any]
-    def __init__(self, future: Future[_S], fn: Callable[..., _S], args: Iterable[Any], kwargs: Mapping[str, Any]) -> None: ...
-    def run(self) -> None: ...
-    def __class_getitem__(cls, item: Any, /) -> GenericAlias: ...
-
-def _worker(
-    executor_reference: ref[Any],
-    work_queue: queue.SimpleQueue[Any],
-    initializer: Callable[[Unpack[_Ts]], object],
-    initargs: tuple[Unpack[_Ts]],
-) -> None: ...
-
-class BrokenThreadPool(BrokenExecutor): ...
-
-class ThreadPoolExecutor(Executor):
-    _max_workers: int
-    _idle_semaphore: Semaphore
-    _threads: AbstractSet[Thread]
-    _broken: bool
-    _shutdown: bool
-    _shutdown_lock: Lock
-    _thread_name_prefix: str | None
-    _initializer: Callable[..., None] | None
-    _initargs: tuple[Any, ...]
-    _work_queue: queue.SimpleQueue[_WorkItem[Any]]
-    @overload
-    def __init__(
-        self,
-        max_workers: int | None = None,
-        thread_name_prefix: str = "",
-        initializer: Callable[[], object] | None = None,
-        initargs: tuple[()] = (),
-    ) -> None: ...
-    @overload
-    def __init__(
-        self,
-        max_workers: int | None = None,
-        thread_name_prefix: str = "",
-        *,
-        initializer: Callable[[Unpack[_Ts]], object],
-        initargs: tuple[Unpack[_Ts]],
-    ) -> None: ...
-    @overload
-    def __init__(
-        self,
-        max_workers: int | None,
-        thread_name_prefix: str,
-        initializer: Callable[[Unpack[_Ts]], object],
-        initargs: tuple[Unpack[_Ts]],
-    ) -> None: ...
-    def _adjust_thread_count(self) -> None: ...
-    def _initializer_failed(self) -> None: ...

crates/red_knot_vendored/vendor/typeshed/stdlib/getpass.pyi

@@ -1,8 +0,0 @@
-from typing import TextIO
-
-__all__ = ["getpass", "getuser", "GetPassWarning"]
-
-def getpass(prompt: str = "Password: ", stream: TextIO | None = None) -> str: ...
-def getuser() -> str: ...
-
-class GetPassWarning(UserWarning): ...

crates/red_knot_vendored/vendor/typeshed/stdlib/nturl2path.pyi

@@ -1,2 +0,0 @@
-def url2pathname(url: str) -> str: ...
-def pathname2url(p: str) -> str: ...

crates/red_knot_vendored/vendor/typeshed/stdlib/tomllib.pyi

@@ -1,10 +0,0 @@
-from _typeshed import SupportsRead
-from collections.abc import Callable
-from typing import Any
-
-__all__ = ("loads", "load", "TOMLDecodeError")
-
-class TOMLDecodeError(ValueError): ...
-
-def load(fp: SupportsRead[bytes], /, *, parse_float: Callable[[str], Any] = ...) -> dict[str, Any]: ...
-def loads(s: str, /, *, parse_float: Callable[[str], Any] = ...) -> dict[str, Any]: ...

crates/ruff/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "ruff"
-version = "0.11.8"
+version = "0.11.11"
 publish = true
 authors = { workspace = true }
 edition = { workspace = true }
@@ -20,6 +20,7 @@ ruff_graph = { workspace = true, features = ["serde", "clap"] }
 ruff_linter = { workspace = true, features = ["clap"] }
 ruff_macros = { workspace = true }
 ruff_notebook = { workspace = true }
+ruff_options_metadata = { workspace = true, features = ["serde"] }
 ruff_python_ast = { workspace = true }
 ruff_python_formatter = { workspace = true }
 ruff_python_parser = { workspace = true }
@@ -30,7 +31,7 @@ ruff_workspace = { workspace = true }
 
 anyhow = { workspace = true }
 argfile = { workspace = true }
-bincode = { workspace = true }
+bincode = { workspace = true, features = ["serde"] }
 bitflags = { workspace = true }
 cachedir = { workspace = true }
 clap = { workspace = true, features = ["derive", "env", "wrap_help"] }
@@ -83,7 +84,7 @@ dist = true
 [target.'cfg(target_os = "windows")'.dependencies]
 mimalloc = { workspace = true }
 
-[target.'cfg(all(not(target_os = "windows"), not(target_os = "openbsd"), not(target_os = "aix"), any(target_arch = "x86_64", target_arch = "aarch64", target_arch = "powerpc64")))'.dependencies]
+[target.'cfg(all(not(target_os = "windows"), not(target_os = "openbsd"), not(target_os = "aix"), not(target_os = "android"), any(target_arch = "x86_64", target_arch = "aarch64", target_arch = "powerpc64")))'.dependencies]
 tikv-jemallocator = { workspace = true }
 
 [lints]

crates/ruff/build.rs

@@ -13,7 +13,6 @@ fn main() {
 
     commit_info(&workspace_root);
 
-    #[allow(clippy::disallowed_methods)]
     let target = std::env::var("TARGET").unwrap();
     println!("cargo::rustc-env=RUST_HOST_TARGET={target}");
 }

crates/ruff/src/args.rs

@@ -8,7 +8,7 @@ use std::sync::Arc;
 use crate::commands::completions::config::{OptionString, OptionStringParser};
 use anyhow::bail;
 use clap::builder::{TypedValueParser, ValueParserFactory};
-use clap::{command, Parser, Subcommand};
+use clap::{Parser, Subcommand, command};
 use colored::Colorize;
 use itertools::Itertools;
 use path_absolutize::path_dedot;
@@ -22,12 +22,12 @@ use ruff_linter::settings::types::{
     PythonVersion, UnsafeFixes,
 };
 use ruff_linter::{RuleParser, RuleSelector, RuleSelectorParser};
+use ruff_options_metadata::{OptionEntry, OptionsMetadata};
 use ruff_python_ast as ast;
 use ruff_source_file::{LineIndex, OneIndexed, PositionEncoding};
 use ruff_text_size::TextRange;
 use ruff_workspace::configuration::{Configuration, RuleSelection};
 use ruff_workspace::options::{Options, PycodestyleOptions};
-use ruff_workspace::options_base::{OptionEntry, OptionsMetadata};
 use ruff_workspace::resolver::ConfigurationTransformer;
 use rustc_hash::FxHashMap;
 use toml;
@@ -93,7 +93,7 @@ pub struct Args {
     pub(crate) global_options: GlobalConfigArgs,
 }
 
-#[allow(clippy::large_enum_variant)]
+#[expect(clippy::large_enum_variant)]
 #[derive(Debug, clap::Subcommand)]
 pub enum Command {
     /// Run Ruff on the given files or directories.
@@ -177,11 +177,14 @@ pub struct AnalyzeGraphCommand {
     /// The minimum Python version that should be supported.
     #[arg(long, value_enum)]
     target_version: Option<PythonVersion>,
+    /// Path to a virtual environment to use for resolving additional dependencies
+    #[arg(long)]
+    python: Option<PathBuf>,
 }
 
 // The `Parser` derive is for ruff_dev, for ruff `Args` would be sufficient
 #[derive(Clone, Debug, clap::Parser)]
-#[allow(clippy::struct_excessive_bools)]
+#[expect(clippy::struct_excessive_bools)]
 pub struct CheckCommand {
     /// List of files or directories to check.
     #[clap(help = "List of files or directories to check [default: .]")]
@@ -443,7 +446,7 @@ pub struct CheckCommand {
 }
 
 #[derive(Clone, Debug, clap::Parser)]
-#[allow(clippy::struct_excessive_bools)]
+#[expect(clippy::struct_excessive_bools)]
 pub struct FormatCommand {
     /// List of files or directories to format.
     #[clap(help = "List of files or directories to format [default: .]")]
@@ -557,7 +560,7 @@ pub enum HelpFormat {
     Json,
 }
 
-#[allow(clippy::module_name_repetitions)]
+#[expect(clippy::module_name_repetitions)]
 #[derive(Debug, Default, Clone, clap::Args)]
 pub struct LogLevelArgs {
     /// Enable verbose logging.
@@ -796,6 +799,7 @@ impl AnalyzeGraphCommand {
         let format_arguments = AnalyzeGraphArgs {
             files: self.files,
             direction: self.direction,
+            python: self.python,
         };
 
         let cli_overrides = ExplicitConfigOverrides {
@@ -1027,7 +1031,7 @@ Possible choices:
 
 /// CLI settings that are distinct from configuration (commands, lists of files,
 /// etc.).
-#[allow(clippy::struct_excessive_bools)]
+#[expect(clippy::struct_excessive_bools)]
 pub struct CheckArguments {
     pub add_noqa: bool,
     pub diff: bool,
@@ -1046,7 +1050,7 @@ pub struct CheckArguments {
 
 /// CLI settings that are distinct from configuration (commands, lists of files,
 /// etc.).
-#[allow(clippy::struct_excessive_bools)]
+#[expect(clippy::struct_excessive_bools)]
 pub struct FormatArguments {
     pub check: bool,
     pub no_cache: bool,
@@ -1122,10 +1126,10 @@ impl std::fmt::Display for FormatRangeParseError {
                 write!(
                     f,
                     "the start position '{start_invalid}' is greater than the end position '{end_invalid}'.\n  {tip} Try switching start and end: '{end}-{start}'",
-                    start_invalid=start.to_string().bold().yellow(),
-                    end_invalid=end.to_string().bold().yellow(),
-                    start=start.to_string().green().bold(),
-                    end=end.to_string().green().bold()
+                    start_invalid = start.to_string().bold().yellow(),
+                    end_invalid = end.to_string().bold().yellow(),
+                    start = start.to_string().green().bold(),
+                    end = end.to_string().green().bold()
                 )
             }
             FormatRangeParseError::InvalidStart(inner) => inner.write(f, true),
@@ -1226,30 +1230,36 @@ impl LineColumnParseError {
 
         match self {
             LineColumnParseError::ColumnParseError(inner) => {
-                write!(f, "the {range}s column is not a valid number ({inner})'\n  {tip} The format is 'line:column'.")
+                write!(
+                    f,
+                    "the {range}s column is not a valid number ({inner})'\n  {tip} The format is 'line:column'."
+                )
             }
             LineColumnParseError::LineParseError(inner) => {
-                write!(f, "the {range} line is not a valid number ({inner})\n  {tip} The format is 'line:column'.")
+                write!(
+                    f,
+                    "the {range} line is not a valid number ({inner})\n  {tip} The format is 'line:column'."
+                )
             }
             LineColumnParseError::ZeroColumnIndex { line } => {
                 write!(
                     f,
                     "the {range} column is 0, but it should be 1 or greater.\n  {tip} The column numbers start at 1.\n  {tip} Try {suggestion} instead.",
-                    suggestion=format!("{line}:1").green().bold()
+                    suggestion = format!("{line}:1").green().bold()
                 )
             }
             LineColumnParseError::ZeroLineIndex { column } => {
                 write!(
                     f,
                     "the {range} line is 0, but it should be 1 or greater.\n  {tip} The line numbers start at 1.\n  {tip} Try {suggestion} instead.",
-                    suggestion=format!("1:{column}").green().bold()
+                    suggestion = format!("1:{column}").green().bold()
                 )
             }
             LineColumnParseError::ZeroLineAndColumnIndex => {
                 write!(
                     f,
                     "the {range} line and column are both 0, but they should be 1 or greater.\n  {tip} The line and column numbers start at 1.\n  {tip} Try {suggestion} instead.",
-                    suggestion="1:1".to_string().green().bold()
+                    suggestion = "1:1".to_string().green().bold()
                 )
             }
         }
@@ -1261,12 +1271,12 @@ impl LineColumnParseError {
 pub struct AnalyzeGraphArgs {
     pub files: Vec<PathBuf>,
     pub direction: Direction,
+    pub python: Option<PathBuf>,
 }
 
 /// Configuration overrides provided via dedicated CLI flags:
 /// `--line-length`, `--respect-gitignore`, etc.
 #[derive(Clone, Default)]
-#[allow(clippy::struct_excessive_bools)]
 struct ExplicitConfigOverrides {
     dummy_variable_rgx: Option<Regex>,
     exclude: Option<Vec<FilePattern>>,

crates/ruff/src/cache.rs

@@ -3,8 +3,8 @@ use std::fs::{self, File};
 use std::hash::Hasher;
 use std::io::{self, BufReader, Write};
 use std::path::{Path, PathBuf};
-use std::sync::atomic::{AtomicU64, Ordering};
 use std::sync::Mutex;
+use std::sync::atomic::{AtomicU64, Ordering};
 use std::time::{Duration, SystemTime};
 
 use anyhow::{Context, Result};
@@ -13,21 +13,21 @@ use itertools::Itertools;
 use log::{debug, error};
 use rayon::iter::ParallelIterator;
 use rayon::iter::{IntoParallelIterator, ParallelBridge};
+use ruff_linter::codes::Rule;
 use rustc_hash::FxHashMap;
-use serde::{Deserialize, Serialize};
 use tempfile::NamedTempFile;
 
 use ruff_cache::{CacheKey, CacheKeyHasher};
-use ruff_diagnostics::{DiagnosticKind, Fix};
-use ruff_linter::message::{DiagnosticMessage, Message};
+use ruff_diagnostics::Fix;
+use ruff_linter::message::Message;
 use ruff_linter::package::PackageRoot;
-use ruff_linter::{warn_user, VERSION};
+use ruff_linter::{VERSION, warn_user};
 use ruff_macros::CacheKey;
 use ruff_notebook::NotebookIndex;
 use ruff_source_file::SourceFileBuilder;
-use ruff_text_size::{TextRange, TextSize};
-use ruff_workspace::resolver::Resolver;
+use ruff_text_size::{Ranged, TextRange, TextSize};
 use ruff_workspace::Settings;
+use ruff_workspace::resolver::Resolver;
 
 use crate::diagnostics::Diagnostics;
 
@@ -86,7 +86,7 @@ pub(crate) struct Cache {
     changes: Mutex<Vec<Change>>,
     /// The "current" timestamp used as cache for the updates of
     /// [`FileCache::last_seen`]
-    #[allow(clippy::struct_field_names)]
+    #[expect(clippy::struct_field_names)]
     last_seen_cache: u64,
 }
 
@@ -117,13 +117,14 @@ impl Cache {
             }
         };
 
-        let mut package: PackageCache = match bincode::deserialize_from(BufReader::new(file)) {
-            Ok(package) => package,
-            Err(err) => {
-                warn_user!("Failed parse cache file `{}`: {err}", path.display());
-                return Cache::empty(path, package_root);
-            }
-        };
+        let mut package: PackageCache =
+            match bincode::decode_from_reader(BufReader::new(file), bincode::config::standard()) {
+                Ok(package) => package,
+                Err(err) => {
+                    warn_user!("Failed parse cache file `{}`: {err}", path.display());
+                    return Cache::empty(path, package_root);
+                }
+            };
 
         // Sanity check.
         if package.package_root != package_root {
@@ -146,7 +147,7 @@ impl Cache {
         Cache::new(path, package)
     }
 
-    #[allow(clippy::cast_possible_truncation)]
+    #[expect(clippy::cast_possible_truncation)]
     fn new(path: PathBuf, package: PackageCache) -> Self {
         Cache {
             path,
@@ -175,8 +176,8 @@ impl Cache {
 
         // Serialize to in-memory buffer because hyperfine benchmark showed that it's faster than
         // using a `BufWriter` and our cache files are small enough that streaming isn't necessary.
-        let serialized =
-            bincode::serialize(&self.package).context("Failed to serialize cache data")?;
+        let serialized = bincode::encode_to_vec(&self.package, bincode::config::standard())
+            .context("Failed to serialize cache data")?;
         temp_file
             .write_all(&serialized)
             .context("Failed to write serialized cache to temporary file.")?;
@@ -204,7 +205,7 @@ impl Cache {
     }
 
     /// Applies the pending changes without storing the cache to disk.
-    #[allow(clippy::cast_possible_truncation)]
+    #[expect(clippy::cast_possible_truncation)]
     pub(crate) fn save(&mut self) -> bool {
         /// Maximum duration for which we keep a file in cache that hasn't been seen.
         const MAX_LAST_SEEN: Duration = Duration::from_secs(30 * 24 * 60 * 60); // 30 days.
@@ -311,7 +312,7 @@ impl Cache {
 }
 
 /// On disk representation of a cache of a package.
-#[derive(Deserialize, Debug, Serialize)]
+#[derive(bincode::Encode, Debug, bincode::Decode)]
 struct PackageCache {
     /// Path to the root of the package.
     ///
@@ -323,7 +324,7 @@ struct PackageCache {
 }
 
 /// On disk representation of the cache per source file.
-#[derive(Deserialize, Debug, Serialize)]
+#[derive(bincode::Decode, Debug, bincode::Encode)]
 pub(crate) struct FileCache {
     /// Key that determines if the cached item is still valid.
     key: u64,
@@ -347,14 +348,16 @@ impl FileCache {
                 lint.messages
                     .iter()
                     .map(|msg| {
-                        Message::Diagnostic(DiagnosticMessage {
-                            kind: msg.kind.clone(),
-                            range: msg.range,
-                            fix: msg.fix.clone(),
-                            file: file.clone(),
-                            noqa_offset: msg.noqa_offset,
-                            parent: msg.parent,
-                        })
+                        Message::diagnostic(
+                            msg.rule.into(),
+                            msg.body.clone(),
+                            msg.suggestion.clone(),
+                            msg.range,
+                            msg.fix.clone(),
+                            msg.parent,
+                            file.clone(),
+                            msg.noqa_offset,
+                        )
                     })
                     .collect()
             };
@@ -368,7 +371,7 @@ impl FileCache {
     }
 }
 
-#[derive(Debug, Default, Deserialize, Serialize)]
+#[derive(Debug, Default, bincode::Decode, bincode::Encode)]
 struct FileCacheData {
     lint: Option<LintCacheData>,
     formatted: bool,
@@ -406,7 +409,7 @@ pub(crate) fn init(path: &Path) -> Result<()> {
     Ok(())
 }
 
-#[derive(Deserialize, Debug, Serialize, PartialEq)]
+#[derive(bincode::Decode, Debug, bincode::Encode, PartialEq)]
 pub(crate) struct LintCacheData {
     /// Imports made.
     // pub(super) imports: ImportMap,
@@ -419,6 +422,7 @@ pub(crate) struct LintCacheData {
     /// This will be empty if `messages` is empty.
     pub(super) source: String,
     /// Notebook index if this file is a Jupyter Notebook.
+    #[bincode(with_serde)]
     pub(super) notebook_index: Option<NotebookIndex>,
 }
 
@@ -435,20 +439,22 @@ impl LintCacheData {
 
         let messages = messages
             .iter()
-            .filter_map(|message| message.as_diagnostic_message())
-            .map(|msg| {
+            .filter_map(|msg| msg.to_rule().map(|rule| (rule, msg)))
+            .map(|(rule, msg)| {
                 // Make sure that all message use the same source file.
                 assert_eq!(
-                    &msg.file,
+                    msg.source_file(),
                     messages.first().unwrap().source_file(),
                     "message uses a different source file"
                 );
                 CacheMessage {
-                    kind: msg.kind.clone(),
-                    range: msg.range,
+                    rule,
+                    body: msg.body().to_string(),
+                    suggestion: msg.suggestion().map(ToString::to_string),
+                    range: msg.range(),
                     parent: msg.parent,
-                    fix: msg.fix.clone(),
-                    noqa_offset: msg.noqa_offset,
+                    fix: msg.fix().cloned(),
+                    noqa_offset: msg.noqa_offset(),
                 }
             })
             .collect();
@@ -462,14 +468,24 @@ impl LintCacheData {
 }
 
 /// On disk representation of a diagnostic message.
-#[derive(Deserialize, Debug, Serialize, PartialEq)]
+#[derive(bincode::Decode, Debug, bincode::Encode, PartialEq)]
 pub(super) struct CacheMessage {
-    kind: DiagnosticKind,
+    /// The rule for the cached diagnostic.
+    #[bincode(with_serde)]
+    rule: Rule,
+    /// The message body to display to the user, to explain the diagnostic.
+    body: String,
+    /// The message to display to the user, to explain the suggested fix.
+    suggestion: Option<String>,
     /// Range into the message's [`FileCache::source`].
+    #[bincode(with_serde)]
     range: TextRange,
+    #[bincode(with_serde)]
     parent: Option<TextSize>,
+    #[bincode(with_serde)]
     fix: Option<Fix>,
-    noqa_offset: TextSize,
+    #[bincode(with_serde)]
+    noqa_offset: Option<TextSize>,
 }
 
 pub(crate) trait PackageCaches {
@@ -587,7 +603,7 @@ mod tests {
     use std::time::SystemTime;
 
     use anyhow::Result;
-    use filetime::{set_file_mtime, FileTime};
+    use filetime::{FileTime, set_file_mtime};
     use itertools::Itertools;
     use ruff_linter::settings::LinterSettings;
     use test_case::test_case;
@@ -602,8 +618,8 @@ mod tests {
 
     use crate::cache::{self, FileCache, FileCacheData, FileCacheKey};
     use crate::cache::{Cache, RelativePathBuf};
-    use crate::commands::format::{format_path, FormatCommandError, FormatMode, FormatResult};
-    use crate::diagnostics::{lint_path, Diagnostics};
+    use crate::commands::format::{FormatCommandError, FormatMode, FormatResult, format_path};
+    use crate::diagnostics::{Diagnostics, lint_path};
 
     #[test_case("../ruff_linter/resources/test/fixtures", "ruff_tests/cache_same_results_ruff_linter"; "ruff_linter_fixtures")]
     #[test_case("../ruff_notebook/resources/test/fixtures", "ruff_tests/cache_same_results_ruff_notebook"; "ruff_notebook_fixtures")]
@@ -616,7 +632,7 @@ mod tests {
         let settings = Settings {
             cache_dir,
             linter: LinterSettings {
-                unresolved_target_version: PythonVersion::latest(),
+                unresolved_target_version: PythonVersion::latest().into(),
                 ..Default::default()
             },
             ..Settings::default()
@@ -834,7 +850,6 @@ mod tests {
         // Regression test for issue #3086.
 
         #[cfg(unix)]
-        #[allow(clippy::items_after_statements)]
         fn flip_execute_permission_bit(path: &Path) -> io::Result<()> {
             use std::os::unix::fs::PermissionsExt;
             let file = fs::OpenOptions::new().write(true).open(path)?;
@@ -843,7 +858,6 @@ mod tests {
         }
 
         #[cfg(windows)]
-        #[allow(clippy::items_after_statements)]
         fn flip_read_only_permission(path: &Path) -> io::Result<()> {
             let file = fs::OpenOptions::new().write(true).open(path)?;
             let mut perms = file.metadata()?.permissions();

crates/ruff/src/commands/add_noqa.rs

@@ -11,7 +11,7 @@ use ruff_linter::source_kind::SourceKind;
 use ruff_linter::warn_user_once;
 use ruff_python_ast::{PySourceType, SourceType};
 use ruff_workspace::resolver::{
-    match_exclusion, python_files_in_path, PyprojectConfig, ResolvedFile,
+    PyprojectConfig, ResolvedFile, match_exclusion, python_files_in_path,
 };
 
 use crate::args::ConfigArguments;

crates/ruff/src/commands/analyze_graph.rs

@@ -1,6 +1,6 @@
 use crate::args::{AnalyzeGraphArgs, ConfigArguments};
 use crate::resolve::resolve;
-use crate::{resolve_default_files, ExitStatus};
+use crate::{ExitStatus, resolve_default_files};
 use anyhow::Result;
 use log::{debug, warn};
 use path_absolutize::CWD;
@@ -9,7 +9,7 @@ use ruff_graph::{Direction, ImportMap, ModuleDb, ModuleImports};
 use ruff_linter::package::PackageRoot;
 use ruff_linter::{warn_user, warn_user_once};
 use ruff_python_ast::{PySourceType, SourceType};
-use ruff_workspace::resolver::{match_exclusion, python_files_in_path, ResolvedFile};
+use ruff_workspace::resolver::{ResolvedFile, match_exclusion, python_files_in_path};
 use rustc_hash::FxHashMap;
 use std::io::Write;
 use std::path::{Path, PathBuf};
@@ -75,6 +75,8 @@ pub(crate) fn analyze_graph(
             .target_version
             .as_tuple()
             .into(),
+        args.python
+            .and_then(|python| SystemPathBuf::from_path_buf(python).ok()),
     )?;
 
     let imports = {

crates/ruff/src/commands/check.rs

@@ -17,12 +17,12 @@ use ruff_linter::message::Message;
 use ruff_linter::package::PackageRoot;
 use ruff_linter::registry::Rule;
 use ruff_linter::settings::types::UnsafeFixes;
-use ruff_linter::settings::{flags, LinterSettings};
-use ruff_linter::{fs, warn_user_once, IOError};
+use ruff_linter::settings::{LinterSettings, flags};
+use ruff_linter::{IOError, fs, warn_user_once};
 use ruff_source_file::SourceFileBuilder;
-use ruff_text_size::{TextRange, TextSize};
+use ruff_text_size::TextRange;
 use ruff_workspace::resolver::{
-    match_exclusion, python_files_in_path, PyprojectConfig, ResolvedFile,
+    PyprojectConfig, ResolvedFile, match_exclusion, python_files_in_path,
 };
 
 use crate::args::ConfigArguments;
@@ -30,7 +30,6 @@ use crate::cache::{Cache, PackageCacheMap, PackageCaches};
 use crate::diagnostics::Diagnostics;
 
 /// Run the linter over a collection of files.
-#[allow(clippy::too_many_arguments)]
 pub(crate) fn check(
     files: &[PathBuf],
     pyproject_config: &PyprojectConfig,
@@ -134,7 +133,7 @@ pub(crate) fn check(
                         vec![Message::from_diagnostic(
                             Diagnostic::new(IOError { message }, TextRange::default()),
                             dummy,
-                            TextSize::default(),
+                            None,
                         )],
                         FxHashMap::default(),
                     )
@@ -181,7 +180,6 @@ pub(crate) fn check(
 
 /// Wraps [`lint_path`](crate::diagnostics::lint_path) in a [`catch_unwind`](std::panic::catch_unwind) and emits
 /// a diagnostic if the linting the file panics.
-#[allow(clippy::too_many_arguments)]
 fn lint_path(
     path: &Path,
     package: Option<PackageRoot<'_>>,
@@ -230,9 +228,9 @@ mod test {
     use ruff_linter::message::{Emitter, EmitterContext, TextEmitter};
     use ruff_linter::registry::Rule;
     use ruff_linter::settings::types::UnsafeFixes;
-    use ruff_linter::settings::{flags, LinterSettings};
-    use ruff_workspace::resolver::{PyprojectConfig, PyprojectDiscoveryStrategy};
+    use ruff_linter::settings::{LinterSettings, flags};
     use ruff_workspace::Settings;
+    use ruff_workspace::resolver::{PyprojectConfig, PyprojectDiscoveryStrategy};
 
     use crate::args::ConfigArguments;
 

crates/ruff/src/commands/check_stdin.rs

@@ -4,10 +4,10 @@ use anyhow::Result;
 use ruff_linter::package::PackageRoot;
 use ruff_linter::packaging;
 use ruff_linter::settings::flags;
-use ruff_workspace::resolver::{match_exclusion, python_file_at_path, PyprojectConfig, Resolver};
+use ruff_workspace::resolver::{PyprojectConfig, Resolver, match_exclusion, python_file_at_path};
 
 use crate::args::ConfigArguments;
-use crate::diagnostics::{lint_stdin, Diagnostics};
+use crate::diagnostics::{Diagnostics, lint_stdin};
 use crate::stdin::{parrot_stdin, read_from_stdin};
 
 /// Run the linter over a single file, read from `stdin`.

crates/ruff/src/commands/completions/config.rs

@@ -2,10 +2,8 @@ use clap::builder::{PossibleValue, TypedValueParser, ValueParserFactory};
 use itertools::Itertools;
 use std::str::FromStr;
 
-use ruff_workspace::{
-    options::Options,
-    options_base::{OptionField, OptionSet, OptionsMetadata, Visit},
-};
+use ruff_options_metadata::{OptionField, OptionSet, OptionsMetadata, Visit};
+use ruff_workspace::options::Options;
 
 #[derive(Default)]
 struct CollectOptionsVisitor {

crates/ruff/src/commands/config.rs

@@ -1,11 +1,11 @@
-use anyhow::{anyhow, Result};
+use anyhow::{Result, anyhow};
 
 use crate::args::HelpFormat;
 
+use ruff_options_metadata::OptionsMetadata;
 use ruff_workspace::options::Options;
-use ruff_workspace::options_base::OptionsMetadata;
 
-#[allow(clippy::print_stdout)]
+#[expect(clippy::print_stdout)]
 pub(crate) fn config(key: Option<&str>, format: HelpFormat) -> Result<()> {
     match key {
         None => {

crates/ruff/src/commands/format.rs

@@ -1,7 +1,7 @@
 use std::fmt::{Display, Formatter};
 use std::fs::File;
 use std::io;
-use std::io::{stderr, stdout, Write};
+use std::io::{Write, stderr, stdout};
 use std::path::{Path, PathBuf};
 use std::time::Instant;
 
@@ -16,7 +16,7 @@ use rustc_hash::FxHashSet;
 use thiserror::Error;
 use tracing::debug;
 
-use ruff_db::panic::{catch_unwind, PanicError};
+use ruff_db::panic::{PanicError, catch_unwind};
 use ruff_diagnostics::SourceMap;
 use ruff_linter::fs;
 use ruff_linter::logging::{DisplayParseError, LogLevel};
@@ -26,16 +26,16 @@ use ruff_linter::rules::flake8_quotes::settings::Quote;
 use ruff_linter::source_kind::{SourceError, SourceKind};
 use ruff_linter::warn_user_once;
 use ruff_python_ast::{PySourceType, SourceType};
-use ruff_python_formatter::{format_module_source, format_range, FormatModuleError, QuoteStyle};
+use ruff_python_formatter::{FormatModuleError, QuoteStyle, format_module_source, format_range};
 use ruff_source_file::LineIndex;
 use ruff_text_size::{TextLen, TextRange, TextSize};
-use ruff_workspace::resolver::{match_exclusion, python_files_in_path, ResolvedFile, Resolver};
 use ruff_workspace::FormatterSettings;
+use ruff_workspace::resolver::{ResolvedFile, Resolver, match_exclusion, python_files_in_path};
 
 use crate::args::{ConfigArguments, FormatArguments, FormatRange};
 use crate::cache::{Cache, FileCacheKey, PackageCacheMap, PackageCaches};
 use crate::resolve::resolve;
-use crate::{resolve_default_files, ExitStatus};
+use crate::{ExitStatus, resolve_default_files};
 
 #[derive(Debug, Copy, Clone, is_macro::Is)]
 pub(crate) enum FormatMode {
@@ -362,7 +362,7 @@ pub(crate) fn format_source(
                 })
             } else {
                 // Using `Printed::into_code` requires adding `ruff_formatter` as a direct dependency, and I suspect that Rust can optimize the closure away regardless.
-                #[allow(clippy::redundant_closure_for_method_calls)]
+                #[expect(clippy::redundant_closure_for_method_calls)]
                 format_module_source(unformatted, options).map(|formatted| formatted.into_code())
             };
 
@@ -821,9 +821,14 @@ pub(super) fn warn_incompatible_formatter_settings(resolver: &Resolver) {
             .collect();
         rule_names.sort();
         if let [rule] = rule_names.as_slice() {
-            warn_user_once!("The following rule may cause conflicts when used with the formatter: {rule}. To avoid unexpected behavior, we recommend disabling this rule, either by removing it from the `select` or `extend-select` configuration, or adding it to the `ignore` configuration.");
+            warn_user_once!(
+                "The following rule may cause conflicts when used with the formatter: {rule}. To avoid unexpected behavior, we recommend disabling this rule, either by removing it from the `lint.select` or `lint.extend-select` configuration, or adding it to the `lint.ignore` configuration."
+            );
         } else {
-            warn_user_once!("The following rules may cause conflicts when used with the formatter: {}. To avoid unexpected behavior, we recommend disabling these rules, either by removing them from the `select` or `extend-select` configuration, or adding them to the `ignore` configuration.", rule_names.join(", "));
+            warn_user_once!(
+                "The following rules may cause conflicts when used with the formatter: {}. To avoid unexpected behavior, we recommend disabling these rules, either by removing them from the `lint.select` or `lint.extend-select` configuration, or adding them to the `lint.ignore` configuration.",
+                rule_names.join(", ")
+            );
         }
     }
 
@@ -833,7 +838,9 @@ pub(super) fn warn_incompatible_formatter_settings(resolver: &Resolver) {
         if setting.linter.rules.enabled(Rule::TabIndentation)
             && setting.formatter.indent_style.is_tab()
         {
-            warn_user_once!("The `format.indent-style=\"tab\"` option is incompatible with `W191`, which lints against all uses of tabs. We recommend disabling these rules when using the formatter, which enforces a consistent indentation style. Alternatively, set the `format.indent-style` option to `\"space\"`.");
+            warn_user_once!(
+                "The `format.indent-style=\"tab\"` option is incompatible with `W191`, which lints against all uses of tabs. We recommend disabling these rules when using the formatter, which enforces a consistent indentation style. Alternatively, set the `format.indent-style` option to `\"space\"`."
+            );
         }
 
         if !setting
@@ -846,14 +853,18 @@ pub(super) fn warn_incompatible_formatter_settings(resolver: &Resolver) {
                 .enabled(Rule::MultiLineImplicitStringConcatenation)
             && !setting.linter.flake8_implicit_str_concat.allow_multiline
         {
-            warn_user_once!("The `lint.flake8-implicit-str-concat.allow-multiline = false` option is incompatible with the formatter unless `ISC001` is enabled. We recommend enabling `ISC001` or setting `allow-multiline=true`.");
+            warn_user_once!(
+                "The `lint.flake8-implicit-str-concat.allow-multiline = false` option is incompatible with the formatter unless `ISC001` is enabled. We recommend enabling `ISC001` or setting `allow-multiline=true`."
+            );
         }
 
         // Validate all rules that rely on tab styles.
         if setting.linter.rules.enabled(Rule::DocstringTabIndentation)
             && setting.formatter.indent_style.is_tab()
         {
-            warn_user_once!("The `format.indent-style=\"tab\"` option is incompatible with `D206`, with requires space-based indentation. We recommend disabling these rules when using the formatter, which enforces a consistent indentation style. Alternatively, set the `format.indent-style` option to `\"space\"`.");
+            warn_user_once!(
+                "The `format.indent-style=\"tab\"` option is incompatible with `D206`, with requires space-based indentation. We recommend disabling these rules when using the formatter, which enforces a consistent indentation style. Alternatively, set the `format.indent-style` option to `\"space\"`."
+            );
         }
 
         // Validate all rules that rely on custom indent widths.
@@ -862,7 +873,9 @@ pub(super) fn warn_incompatible_formatter_settings(resolver: &Resolver) {
             Rule::IndentationWithInvalidMultipleComment,
         ]) && setting.formatter.indent_width.value() != 4
         {
-            warn_user_once!("The `format.indent-width` option with a value other than 4 is incompatible with `E111` and `E114`. We recommend disabling these rules when using the formatter, which enforces a consistent indentation width. Alternatively, set the `format.indent-width` option to `4`.");
+            warn_user_once!(
+                "The `format.indent-width` option with a value other than 4 is incompatible with `E111` and `E114`. We recommend disabling these rules when using the formatter, which enforces a consistent indentation width. Alternatively, set the `format.indent-width` option to `4`."
+            );
         }
 
         // Validate all rules that rely on quote styles.
@@ -876,10 +889,14 @@ pub(super) fn warn_incompatible_formatter_settings(resolver: &Resolver) {
                 setting.formatter.quote_style,
             ) {
                 (Quote::Double, QuoteStyle::Single) => {
-                    warn_user_once!("The `flake8-quotes.inline-quotes=\"double\"` option is incompatible with the formatter's `format.quote-style=\"single\"`. We recommend disabling `Q000` and `Q003` when using the formatter, which enforces a consistent quote style. Alternatively, set both options to either `\"single\"` or `\"double\"`.");
+                    warn_user_once!(
+                        "The `flake8-quotes.inline-quotes=\"double\"` option is incompatible with the formatter's `format.quote-style=\"single\"`. We recommend disabling `Q000` and `Q003` when using the formatter, which enforces a consistent quote style. Alternatively, set both options to either `\"single\"` or `\"double\"`."
+                    );
                 }
                 (Quote::Single, QuoteStyle::Double) => {
-                    warn_user_once!("The `flake8-quotes.inline-quotes=\"single\"` option is incompatible with the formatter's `format.quote-style=\"double\"`. We recommend disabling `Q000` and `Q003` when using the formatter, which enforces a consistent quote style. Alternatively, set both options to either `\"single\"` or `\"double\"`.");
+                    warn_user_once!(
+                        "The `flake8-quotes.inline-quotes=\"single\"` option is incompatible with the formatter's `format.quote-style=\"double\"`. We recommend disabling `Q000` and `Q003` when using the formatter, which enforces a consistent quote style. Alternatively, set both options to either `\"single\"` or `\"double\"`."
+                    );
                 }
                 _ => {}
             }
@@ -892,7 +909,9 @@ pub(super) fn warn_incompatible_formatter_settings(resolver: &Resolver) {
                 QuoteStyle::Single | QuoteStyle::Double
             )
         {
-            warn_user_once!("The `flake8-quotes.multiline-quotes=\"single\"` option is incompatible with the formatter. We recommend disabling `Q001` when using the formatter, which enforces double quotes for multiline strings. Alternatively, set the `flake8-quotes.multiline-quotes` option to `\"double\"`.`");
+            warn_user_once!(
+                "The `flake8-quotes.multiline-quotes=\"single\"` option is incompatible with the formatter. We recommend disabling `Q001` when using the formatter, which enforces double quotes for multiline strings. Alternatively, set the `flake8-quotes.multiline-quotes` option to `\"double\"`.`"
+            );
         }
 
         if setting.linter.rules.enabled(Rule::BadQuotesDocstring)
@@ -902,7 +921,9 @@ pub(super) fn warn_incompatible_formatter_settings(resolver: &Resolver) {
                 QuoteStyle::Single | QuoteStyle::Double
             )
         {
-            warn_user_once!("The `flake8-quotes.docstring-quotes=\"single\"` option is incompatible with the formatter. We recommend disabling `Q002` when using the formatter, which enforces double quotes for docstrings. Alternatively, set the `flake8-quotes.docstring-quotes` option to `\"double\"`.`");
+            warn_user_once!(
+                "The `flake8-quotes.docstring-quotes=\"single\"` option is incompatible with the formatter. We recommend disabling `Q002` when using the formatter, which enforces double quotes for docstrings. Alternatively, set the `flake8-quotes.docstring-quotes` option to `\"double\"`.`"
+            );
         }
 
         // Validate all isort settings.
@@ -910,12 +931,16 @@ pub(super) fn warn_incompatible_formatter_settings(resolver: &Resolver) {
             // The formatter removes empty lines if the value is larger than 2 but always inserts a empty line after imports.
             // Two empty lines are okay because `isort` only uses this setting for top-level imports (not in nested blocks).
             if !matches!(setting.linter.isort.lines_after_imports, 1 | 2 | -1) {
-                warn_user_once!("The isort option `isort.lines-after-imports` with a value other than `-1`, `1` or `2` is incompatible with the formatter. To avoid unexpected behavior, we recommend setting the option to one of: `2`, `1`, or `-1` (default).");
+                warn_user_once!(
+                    "The isort option `isort.lines-after-imports` with a value other than `-1`, `1` or `2` is incompatible with the formatter. To avoid unexpected behavior, we recommend setting the option to one of: `2`, `1`, or `-1` (default)."
+                );
             }
 
             // Values larger than two get reduced to one line by the formatter if the import is in a nested block.
             if setting.linter.isort.lines_between_types > 1 {
-                warn_user_once!("The isort option `isort.lines-between-types` with a value greater than 1 is incompatible with the formatter. To avoid unexpected behavior, we recommend setting the option to one of: `1` or `0` (default).");
+                warn_user_once!(
+                    "The isort option `isort.lines-between-types` with a value greater than 1 is incompatible with the formatter. To avoid unexpected behavior, we recommend setting the option to one of: `1` or `0` (default)."
+                );
             }
 
             // isort inserts a trailing comma which the formatter preserves, but only if `skip-magic-trailing-comma` isn't false.
@@ -924,11 +949,15 @@ pub(super) fn warn_incompatible_formatter_settings(resolver: &Resolver) {
                 && !setting.linter.isort.force_single_line
             {
                 if setting.linter.isort.force_wrap_aliases {
-                    warn_user_once!("The isort option `isort.force-wrap-aliases` is incompatible with the formatter `format.skip-magic-trailing-comma=true` option. To avoid unexpected behavior, we recommend either setting `isort.force-wrap-aliases=false` or `format.skip-magic-trailing-comma=false`.");
+                    warn_user_once!(
+                        "The isort option `isort.force-wrap-aliases` is incompatible with the formatter `format.skip-magic-trailing-comma=true` option. To avoid unexpected behavior, we recommend either setting `isort.force-wrap-aliases=false` or `format.skip-magic-trailing-comma=false`."
+                    );
                 }
 
                 if setting.linter.isort.split_on_trailing_comma {
-                    warn_user_once!("The isort option `isort.split-on-trailing-comma` is incompatible with the formatter `format.skip-magic-trailing-comma=true` option. To avoid unexpected behavior, we recommend either setting `isort.split-on-trailing-comma=false` or `format.skip-magic-trailing-comma=false`.");
+                    warn_user_once!(
+                        "The isort option `isort.split-on-trailing-comma` is incompatible with the formatter `format.skip-magic-trailing-comma=true` option. To avoid unexpected behavior, we recommend either setting `isort.split-on-trailing-comma=false` or `format.skip-magic-trailing-comma=false`."
+                    );
                 }
             }
         }

crates/ruff/src/commands/format_stdin.rs

@@ -6,17 +6,17 @@ use log::error;
 
 use ruff_linter::source_kind::SourceKind;
 use ruff_python_ast::{PySourceType, SourceType};
-use ruff_workspace::resolver::{match_exclusion, python_file_at_path, Resolver};
 use ruff_workspace::FormatterSettings;
+use ruff_workspace::resolver::{Resolver, match_exclusion, python_file_at_path};
 
+use crate::ExitStatus;
 use crate::args::{ConfigArguments, FormatArguments, FormatRange};
 use crate::commands::format::{
-    format_source, warn_incompatible_formatter_settings, FormatCommandError, FormatMode,
-    FormatResult, FormattedSource,
+    FormatCommandError, FormatMode, FormatResult, FormattedSource, format_source,
+    warn_incompatible_formatter_settings,
 };
 use crate::resolve::resolve;
 use crate::stdin::{parrot_stdin, read_from_stdin};
-use crate::ExitStatus;
 
 /// Run the formatter over a single file, read from `stdin`.
 pub(crate) fn format_stdin(

crates/ruff/src/commands/rule.rs

@@ -19,7 +19,7 @@ struct Explanation<'a> {
     summary: &'a str,
     message_formats: &'a [&'a str],
     fix: String,
-    #[allow(clippy::struct_field_names)]
+    #[expect(clippy::struct_field_names)]
     explanation: Option<&'a str>,
     preview: bool,
 }

crates/ruff/src/commands/show_files.rs

@@ -5,7 +5,7 @@ use anyhow::Result;
 use itertools::Itertools;
 
 use ruff_linter::warn_user_once;
-use ruff_workspace::resolver::{python_files_in_path, PyprojectConfig, ResolvedFile};
+use ruff_workspace::resolver::{PyprojectConfig, ResolvedFile, python_files_in_path};
 
 use crate::args::ConfigArguments;
 

crates/ruff/src/commands/show_settings.rs

@@ -1,10 +1,10 @@
 use std::io::Write;
 use std::path::PathBuf;
 
-use anyhow::{bail, Result};
+use anyhow::{Result, bail};
 use itertools::Itertools;
 
-use ruff_workspace::resolver::{python_files_in_path, PyprojectConfig, ResolvedFile};
+use ruff_workspace::resolver::{PyprojectConfig, ResolvedFile, python_files_in_path};
 
 use crate::args::ConfigArguments;
 

crates/ruff/src/diagnostics.rs

@@ -14,18 +14,18 @@ use rustc_hash::FxHashMap;
 
 use ruff_diagnostics::Diagnostic;
 use ruff_linter::codes::Rule;
-use ruff_linter::linter::{lint_fix, lint_only, FixTable, FixerResult, LinterResult, ParseSource};
-use ruff_linter::message::{Message, SyntaxErrorMessage};
+use ruff_linter::linter::{FixTable, FixerResult, LinterResult, ParseSource, lint_fix, lint_only};
+use ruff_linter::message::Message;
 use ruff_linter::package::PackageRoot;
 use ruff_linter::pyproject_toml::lint_pyproject_toml;
 use ruff_linter::settings::types::UnsafeFixes;
-use ruff_linter::settings::{flags, LinterSettings};
+use ruff_linter::settings::{LinterSettings, flags};
 use ruff_linter::source_kind::{SourceError, SourceKind};
-use ruff_linter::{fs, IOError};
+use ruff_linter::{IOError, fs};
 use ruff_notebook::{Notebook, NotebookError, NotebookIndex};
 use ruff_python_ast::{PySourceType, SourceType, TomlSourceType};
 use ruff_source_file::SourceFileBuilder;
-use ruff_text_size::{TextRange, TextSize};
+use ruff_text_size::TextRange;
 use ruff_workspace::Settings;
 
 use crate::cache::{Cache, FileCacheKey, LintCacheData};
@@ -71,7 +71,7 @@ impl Diagnostics {
                                 TextRange::default(),
                             ),
                             source_file,
-                            TextSize::default(),
+                            None,
                         )],
                         FxHashMap::default(),
                     )
@@ -102,11 +102,7 @@ impl Diagnostics {
                 let name = path.map_or_else(|| "-".into(), Path::to_string_lossy);
                 let dummy = SourceFileBuilder::new(name, "").finish();
                 Self::new(
-                    vec![Message::SyntaxError(SyntaxErrorMessage {
-                        message: err.to_string(),
-                        range: TextRange::default(),
-                        file: dummy,
-                    })],
+                    vec![Message::syntax_error(err, TextRange::default(), dummy)],
                     FxHashMap::default(),
                 )
             }

crates/ruff/src/lib.rs

@@ -1,7 +1,7 @@
 #![allow(clippy::print_stdout)]
 
 use std::fs::File;
-use std::io::{self, stdout, BufWriter, Write};
+use std::io::{self, BufWriter, Write, stdout};
 use std::num::NonZeroUsize;
 use std::path::{Path, PathBuf};
 use std::process::ExitCode;
@@ -11,10 +11,10 @@ use anyhow::Result;
 use clap::CommandFactory;
 use colored::Colorize;
 use log::warn;
-use notify::{recommended_watcher, RecursiveMode, Watcher};
+use notify::{RecursiveMode, Watcher, recommended_watcher};
 
 use args::{GlobalConfigArgs, ServerCommand};
-use ruff_linter::logging::{set_up_logging, LogLevel};
+use ruff_linter::logging::{LogLevel, set_up_logging};
 use ruff_linter::settings::flags::FixMode;
 use ruff_linter::settings::types::OutputFormat;
 use ruff_linter::{fs, warn_user, warn_user_once};
@@ -134,7 +134,7 @@ pub fn run(
     {
         let default_panic_hook = std::panic::take_hook();
         std::panic::set_hook(Box::new(move |info| {
-            #[allow(clippy::print_stderr)]
+            #[expect(clippy::print_stderr)]
             {
                 eprintln!(
                     r#"
@@ -326,7 +326,7 @@ pub fn check(args: CheckCommand, global_options: GlobalConfigArgs) -> Result<Exi
             commands::add_noqa::add_noqa(&files, &pyproject_config, &config_arguments)?;
         if modifications > 0 && config_arguments.log_level >= LogLevel::Default {
             let s = if modifications == 1 { "" } else { "s" };
-            #[allow(clippy::print_stderr)]
+            #[expect(clippy::print_stderr)]
             {
                 eprintln!("Added {modifications} noqa directive{s}.");
             }
@@ -488,7 +488,7 @@ pub fn check(args: CheckCommand, global_options: GlobalConfigArgs) -> Result<Exi
 mod test_file_change_detector {
     use std::path::PathBuf;
 
-    use crate::{change_detected, ChangeKind};
+    use crate::{ChangeKind, change_detected};
 
     #[test]
     fn detect_correct_file_change() {

crates/ruff/src/main.rs

@@ -5,7 +5,7 @@ use clap::Parser;
 use colored::Colorize;
 
 use ruff::args::Args;
-use ruff::{run, ExitStatus};
+use ruff::{ExitStatus, run};
 
 #[cfg(target_os = "windows")]
 #[global_allocator]
@@ -15,6 +15,7 @@ static GLOBAL: mimalloc::MiMalloc = mimalloc::MiMalloc;
     not(target_os = "windows"),
     not(target_os = "openbsd"),
     not(target_os = "aix"),
+    not(target_os = "android"),
     any(
         target_arch = "x86_64",
         target_arch = "aarch64",

crates/ruff/src/printer.rs

@@ -1,23 +1,22 @@
 use std::cmp::Reverse;
-use std::fmt::Display;
 use std::hash::Hash;
 use std::io::Write;
 
 use anyhow::Result;
 use bitflags::bitflags;
 use colored::Colorize;
-use itertools::{iterate, Itertools};
+use itertools::{Itertools, iterate};
+use ruff_linter::codes::NoqaCode;
 use serde::Serialize;
 
 use ruff_linter::fs::relativize_path;
 use ruff_linter::logging::LogLevel;
 use ruff_linter::message::{
     AzureEmitter, Emitter, EmitterContext, GithubEmitter, GitlabEmitter, GroupedEmitter,
-    JsonEmitter, JsonLinesEmitter, JunitEmitter, Message, MessageKind, PylintEmitter,
-    RdjsonEmitter, SarifEmitter, TextEmitter,
+    JsonEmitter, JsonLinesEmitter, JunitEmitter, Message, PylintEmitter, RdjsonEmitter,
+    SarifEmitter, TextEmitter,
 };
 use ruff_linter::notify_user;
-use ruff_linter::registry::Rule;
 use ruff_linter::settings::flags::{self};
 use ruff_linter::settings::types::{OutputFormat, UnsafeFixes};
 
@@ -37,59 +36,12 @@ bitflags! {
 
 #[derive(Serialize)]
 struct ExpandedStatistics {
-    code: Option<SerializeRuleAsCode>,
-    name: SerializeMessageKindAsTitle,
+    code: Option<NoqaCode>,
+    name: &'static str,
     count: usize,
     fixable: bool,
 }
 
-#[derive(Copy, Clone)]
-struct SerializeRuleAsCode(Rule);
-
-impl Serialize for SerializeRuleAsCode {
-    fn serialize<S>(&self, serializer: S) -> std::result::Result<S::Ok, S::Error>
-    where
-        S: serde::Serializer,
-    {
-        serializer.serialize_str(&self.0.noqa_code().to_string())
-    }
-}
-
-impl Display for SerializeRuleAsCode {
-    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-        write!(f, "{}", self.0.noqa_code())
-    }
-}
-
-impl From<Rule> for SerializeRuleAsCode {
-    fn from(rule: Rule) -> Self {
-        Self(rule)
-    }
-}
-
-struct SerializeMessageKindAsTitle(MessageKind);
-
-impl Serialize for SerializeMessageKindAsTitle {
-    fn serialize<S>(&self, serializer: S) -> std::result::Result<S::Ok, S::Error>
-    where
-        S: serde::Serializer,
-    {
-        serializer.serialize_str(self.0.as_str())
-    }
-}
-
-impl Display for SerializeMessageKindAsTitle {
-    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-        f.write_str(self.0.as_str())
-    }
-}
-
-impl From<MessageKind> for SerializeMessageKindAsTitle {
-    fn from(kind: MessageKind) -> Self {
-        Self(kind)
-    }
-}
-
 pub(crate) struct Printer {
     format: OutputFormat,
     log_level: LogLevel,
@@ -157,7 +109,8 @@ impl Printer {
                             } else {
                                 "es"
                             };
-                            writeln!(writer,
+                            writeln!(
+                                writer,
                                 "{fix_prefix} {} fixable with the `--fix` option ({} hidden fix{es} can be enabled with the `--unsafe-fixes` option).",
                                 fixables.applicable, fixables.inapplicable_unsafe
                             )?;
@@ -175,7 +128,8 @@ impl Printer {
                             } else {
                                 "es"
                             };
-                            writeln!(writer,
+                            writeln!(
+                                writer,
                                 "No fixes available ({} hidden fix{es} can be enabled with the `--unsafe-fixes` option).",
                                 fixables.inapplicable_unsafe
                             )?;
@@ -205,15 +159,27 @@ impl Printer {
                     if fixed > 0 {
                         let s = if fixed == 1 { "" } else { "s" };
                         if self.fix_mode.is_apply() {
-                            writeln!(writer, "Fixed {fixed} error{s} ({unapplied} additional fix{es} available with `--unsafe-fixes`).")?;
+                            writeln!(
+                                writer,
+                                "Fixed {fixed} error{s} ({unapplied} additional fix{es} available with `--unsafe-fixes`)."
+                            )?;
                         } else {
-                            writeln!(writer, "Would fix {fixed} error{s} ({unapplied} additional fix{es} available with `--unsafe-fixes`).")?;
+                            writeln!(
+                                writer,
+                                "Would fix {fixed} error{s} ({unapplied} additional fix{es} available with `--unsafe-fixes`)."
+                            )?;
                         }
                     } else {
                         if self.fix_mode.is_apply() {
-                            writeln!(writer, "No errors fixed ({unapplied} fix{es} available with `--unsafe-fixes`).")?;
+                            writeln!(
+                                writer,
+                                "No errors fixed ({unapplied} fix{es} available with `--unsafe-fixes`)."
+                            )?;
                         } else {
-                            writeln!(writer, "No errors would be fixed ({unapplied} fix{es} available with `--unsafe-fixes`).")?;
+                            writeln!(
+                                writer,
+                                "No errors would be fixed ({unapplied} fix{es} available with `--unsafe-fixes`)."
+                            )?;
                         }
                     }
                 } else {
@@ -241,7 +207,6 @@ impl Printer {
         }
 
         if !self.flags.intersects(Flags::SHOW_VIOLATIONS) {
-            #[allow(deprecated)]
             if matches!(
                 self.format,
                 OutputFormat::Full | OutputFormat::Concise | OutputFormat::Grouped
@@ -337,21 +302,25 @@ impl Printer {
         let statistics: Vec<ExpandedStatistics> = diagnostics
             .messages
             .iter()
-            .sorted_by_key(|message| (message.rule(), message.fixable()))
-            .fold(vec![], |mut acc: Vec<(&Message, usize)>, message| {
-                if let Some((prev_message, count)) = acc.last_mut() {
-                    if prev_message.rule() == message.rule() {
-                        *count += 1;
-                        return acc;
+            .map(|message| (message.to_noqa_code(), message))
+            .sorted_by_key(|(code, message)| (*code, message.fixable()))
+            .fold(
+                vec![],
+                |mut acc: Vec<((Option<NoqaCode>, &Message), usize)>, (code, message)| {
+                    if let Some(((prev_code, _prev_message), count)) = acc.last_mut() {
+                        if *prev_code == code {
+                            *count += 1;
+                            return acc;
+                        }
                     }
-                }
-                acc.push((message, 1));
-                acc
-            })
+                    acc.push(((code, message), 1));
+                    acc
+                },
+            )
             .iter()
-            .map(|&(message, count)| ExpandedStatistics {
-                code: message.rule().map(std::convert::Into::into),
-                name: message.kind().into(),
+            .map(|&((code, message), count)| ExpandedStatistics {
+                code,
+                name: message.name(),
                 count,
                 fixable: if let Some(fix) = message.fix() {
                     fix.applies(self.unsafe_fixes.required_applicability())

crates/ruff/src/resolve.rs

@@ -1,14 +1,14 @@
 use std::path::Path;
 
-use anyhow::{bail, Result};
+use anyhow::{Result, bail};
 use log::debug;
 use path_absolutize::path_dedot;
 
 use ruff_workspace::configuration::Configuration;
 use ruff_workspace::pyproject::{self, find_fallback_target_version};
 use ruff_workspace::resolver::{
-    resolve_root_settings, ConfigurationOrigin, ConfigurationTransformer, PyprojectConfig,
-    PyprojectDiscoveryStrategy,
+    ConfigurationOrigin, ConfigurationTransformer, PyprojectConfig, PyprojectDiscoveryStrategy,
+    resolve_root_settings,
 };
 
 use ruff_python_ast as ast;

crates/ruff/tests/analyze_graph.rs

@@ -422,3 +422,153 @@ fn nested_imports() -> Result<()> {
 
     Ok(())
 }
+
+/// Test for venv resolution with the `--python` flag.
+///
+/// Based on the [albatross-virtual-workspace] example from the uv repo and the report in [#16598].
+///
+/// [albatross-virtual-workspace]: https://github.com/astral-sh/uv/tree/aa629c4a/scripts/workspaces/albatross-virtual-workspace
+/// [#16598]: https://github.com/astral-sh/ruff/issues/16598
+#[test]
+fn venv() -> Result<()> {
+    let tempdir = TempDir::new()?;
+    let root = ChildPath::new(tempdir.path());
+
+    // packages
+    // ├── albatross
+    // │   ├── check_installed_albatross.py
+    // │   ├── pyproject.toml
+    // │   └── src
+    // │       └── albatross
+    // │           └── __init__.py
+    // └── bird-feeder
+    //     ├── check_installed_bird_feeder.py
+    //     ├── pyproject.toml
+    //     └── src
+    //         └── bird_feeder
+    //             └── __init__.py
+
+    let packages = root.child("packages");
+
+    let albatross = packages.child("albatross");
+    albatross
+        .child("check_installed_albatross.py")
+        .write_str("from albatross import fly")?;
+    albatross
+        .child("pyproject.toml")
+        .write_str(indoc::indoc! {r#"
+        [project]
+        name = "albatross"
+        version = "0.1.0"
+        requires-python = ">=3.12"
+        dependencies = ["bird-feeder", "tqdm>=4,<5"]
+
+        [tool.uv.sources]
+        bird-feeder = { workspace = true }
+    "#})?;
+    albatross
+        .child("src")
+        .child("albatross")
+        .child("__init__.py")
+        .write_str("import tqdm; from bird_feeder import use")?;
+
+    let bird_feeder = packages.child("bird-feeder");
+    bird_feeder
+        .child("check_installed_bird_feeder.py")
+        .write_str("from bird_feeder import use; from albatross import fly")?;
+    bird_feeder
+        .child("pyproject.toml")
+        .write_str(indoc::indoc! {r#"
+        [project]
+        name = "bird-feeder"
+        version = "1.0.0"
+        requires-python = ">=3.12"
+        dependencies = ["anyio>=4.3.0,<5"]
+    "#})?;
+    bird_feeder
+        .child("src")
+        .child("bird_feeder")
+        .child("__init__.py")
+        .write_str("import anyio")?;
+
+    let venv = root.child(".venv");
+    let bin = venv.child("bin");
+    bin.child("python").touch()?;
+    let home = format!("home = {}", bin.to_string_lossy());
+    venv.child("pyvenv.cfg").write_str(&home)?;
+    let site_packages = venv.child("lib").child("python3.12").child("site-packages");
+    site_packages
+        .child("_albatross.pth")
+        .write_str(&albatross.join("src").to_string_lossy())?;
+    site_packages
+        .child("_bird_feeder.pth")
+        .write_str(&bird_feeder.join("src").to_string_lossy())?;
+    site_packages.child("tqdm").child("__init__.py").touch()?;
+
+    // without `--python .venv`, the result should only include dependencies within the albatross
+    // package
+    insta::with_settings!({
+        filters => INSTA_FILTERS.to_vec(),
+    }, {
+        assert_cmd_snapshot!(
+            command().arg("packages/albatross").current_dir(&root),
+            @r#"
+        success: true
+        exit_code: 0
+        ----- stdout -----
+        {
+          "packages/albatross/check_installed_albatross.py": [
+            "packages/albatross/src/albatross/__init__.py"
+          ],
+          "packages/albatross/src/albatross/__init__.py": []
+        }
+
+        ----- stderr -----
+        "#);
+    });
+
+    // with `--python .venv` both workspace and third-party dependencies are included
+    insta::with_settings!({
+        filters => INSTA_FILTERS.to_vec(),
+    }, {
+        assert_cmd_snapshot!(
+            command().args(["--python", ".venv"]).arg("packages/albatross").current_dir(&root),
+            @r#"
+        success: true
+        exit_code: 0
+        ----- stdout -----
+        {
+          "packages/albatross/check_installed_albatross.py": [
+            "packages/albatross/src/albatross/__init__.py"
+          ],
+          "packages/albatross/src/albatross/__init__.py": [
+            ".venv/lib/python3.12/site-packages/tqdm/__init__.py",
+            "packages/bird-feeder/src/bird_feeder/__init__.py"
+          ]
+        }
+
+        ----- stderr -----
+        "#);
+    });
+
+    // test the error message for a non-existent venv. it's important that the `ruff analyze graph`
+    // flag matches the ty flag used to generate the error message (`--python`)
+    insta::with_settings!({
+        filters => INSTA_FILTERS.to_vec(),
+    }, {
+        assert_cmd_snapshot!(
+            command().args(["--python", "none"]).arg("packages/albatross").current_dir(&root),
+            @r"
+        success: false
+        exit_code: 2
+        ----- stdout -----
+
+        ----- stderr -----
+        ruff failed
+          Cause: Invalid search path settings
+          Cause: Failed to discover the site-packages directory: Invalid `--python` argument: `none` could not be canonicalized
+        ");
+    });
+
+    Ok(())
+}

crates/ruff/tests/format.rs

@@ -862,7 +862,7 @@ if condition:
     	print('Should change quotes')
 
     ----- stderr -----
-    warning: The following rule may cause conflicts when used with the formatter: `COM812`. To avoid unexpected behavior, we recommend disabling this rule, either by removing it from the `select` or `extend-select` configuration, or adding it to the `ignore` configuration.
+    warning: The following rule may cause conflicts when used with the formatter: `COM812`. To avoid unexpected behavior, we recommend disabling this rule, either by removing it from the `lint.select` or `lint.extend-select` configuration, or adding it to the `lint.ignore` configuration.
     "#);
     Ok(())
 }
@@ -999,7 +999,7 @@ def say_hy(name: str):
     1 file reformatted
 
     ----- stderr -----
-    warning: The following rule may cause conflicts when used with the formatter: `COM812`. To avoid unexpected behavior, we recommend disabling this rule, either by removing it from the `select` or `extend-select` configuration, or adding it to the `ignore` configuration.
+    warning: The following rule may cause conflicts when used with the formatter: `COM812`. To avoid unexpected behavior, we recommend disabling this rule, either by removing it from the `lint.select` or `lint.extend-select` configuration, or adding it to the `lint.ignore` configuration.
     warning: The `format.indent-style="tab"` option is incompatible with `W191`, which lints against all uses of tabs. We recommend disabling these rules when using the formatter, which enforces a consistent indentation style. Alternatively, set the `format.indent-style` option to `"space"`.
     warning: The `lint.flake8-implicit-str-concat.allow-multiline = false` option is incompatible with the formatter unless `ISC001` is enabled. We recommend enabling `ISC001` or setting `allow-multiline=true`.
     warning: The `format.indent-style="tab"` option is incompatible with `D206`, with requires space-based indentation. We recommend disabling these rules when using the formatter, which enforces a consistent indentation style. Alternatively, set the `format.indent-style` option to `"space"`.
@@ -1059,7 +1059,7 @@ def say_hy(name: str):
     	print(f"Hy {name}")
 
     ----- stderr -----
-    warning: The following rule may cause conflicts when used with the formatter: `COM812`. To avoid unexpected behavior, we recommend disabling this rule, either by removing it from the `select` or `extend-select` configuration, or adding it to the `ignore` configuration.
+    warning: The following rule may cause conflicts when used with the formatter: `COM812`. To avoid unexpected behavior, we recommend disabling this rule, either by removing it from the `lint.select` or `lint.extend-select` configuration, or adding it to the `lint.ignore` configuration.
     warning: The `format.indent-style="tab"` option is incompatible with `W191`, which lints against all uses of tabs. We recommend disabling these rules when using the formatter, which enforces a consistent indentation style. Alternatively, set the `format.indent-style` option to `"space"`.
     warning: The `format.indent-style="tab"` option is incompatible with `D206`, with requires space-based indentation. We recommend disabling these rules when using the formatter, which enforces a consistent indentation style. Alternatively, set the `format.indent-style` option to `"space"`.
     warning: The `flake8-quotes.inline-quotes="single"` option is incompatible with the formatter's `format.quote-style="double"`. We recommend disabling `Q000` and `Q003` when using the formatter, which enforces a consistent quote style. Alternatively, set both options to either `"single"` or `"double"`.
@@ -1199,7 +1199,7 @@ def say_hy(name: str):
     ----- stderr -----
     warning: `incorrect-blank-line-before-class` (D203) and `no-blank-line-before-class` (D211) are incompatible. Ignoring `incorrect-blank-line-before-class`.
     warning: `multi-line-summary-first-line` (D212) and `multi-line-summary-second-line` (D213) are incompatible. Ignoring `multi-line-summary-second-line`.
-    warning: The following rule may cause conflicts when used with the formatter: `COM812`. To avoid unexpected behavior, we recommend disabling this rule, either by removing it from the `select` or `extend-select` configuration, or adding it to the `ignore` configuration.
+    warning: The following rule may cause conflicts when used with the formatter: `COM812`. To avoid unexpected behavior, we recommend disabling this rule, either by removing it from the `lint.select` or `lint.extend-select` configuration, or adding it to the `lint.ignore` configuration.
     ");
     Ok(())
 }

crates/ruff/tests/lint.rs

@@ -1157,18 +1157,20 @@ include = ["*.ipy"]
 
 #[test]
 fn warn_invalid_noqa_with_no_diagnostics() {
-    assert_cmd_snapshot!(Command::new(get_cargo_bin(BIN_NAME))
-        .args(STDIN_BASE_OPTIONS)
-        .args(["--isolated"])
-        .arg("--select")
-        .arg("F401")
-        .arg("-")
-        .pass_stdin(
-            r#"
+    assert_cmd_snapshot!(
+        Command::new(get_cargo_bin(BIN_NAME))
+            .args(STDIN_BASE_OPTIONS)
+            .args(["--isolated"])
+            .arg("--select")
+            .arg("F401")
+            .arg("-")
+            .pass_stdin(
+                r#"
 # ruff: noqa: AAA101
 print("Hello world!")
 "#
-        ));
+            )
+    );
 }
 
 #[test]
@@ -1900,6 +1902,40 @@ def first_square():
     Ok(())
 }
 
+/// Regression test for <https://github.com/astral-sh/ruff/issues/2253>
+#[test]
+fn add_noqa_parent() -> Result<()> {
+    let tempdir = TempDir::new()?;
+    let test_path = tempdir.path().join("noqa.py");
+    fs::write(
+        &test_path,
+        r#"
+from foo import (  # noqa: F401
+		bar
+)
+		"#,
+    )?;
+
+    insta::with_settings!({
+        filters => vec![(tempdir_filter(&tempdir).as_str(), "[TMP]/")]
+    }, {
+        assert_cmd_snapshot!(Command::new(get_cargo_bin(BIN_NAME))
+                .args(STDIN_BASE_OPTIONS)
+                .arg("--add-noqa")
+                .arg("--select=F401")
+                .arg("noqa.py")
+                .current_dir(&tempdir), @r"
+        success: true
+        exit_code: 0
+        ----- stdout -----
+
+        ----- stderr -----
+        ");
+    });
+
+    Ok(())
+}
+
 /// Infer `3.11` from `requires-python` in `pyproject.toml`.
 #[test]
 fn requires_python() -> Result<()> {
@@ -3896,7 +3932,7 @@ from typing import Union;foo: Union[int, str] = 1
         linter.per_file_ignores = {}
         linter.safety_table.forced_safe = []
         linter.safety_table.forced_unsafe = []
-        linter.unresolved_target_version = 3.9
+        linter.unresolved_target_version = none
         linter.per_file_target_version = {}
         linter.preview = disabled
         linter.explicit_preview_rules = false
@@ -4181,7 +4217,7 @@ from typing import Union;foo: Union[int, str] = 1
         linter.per_file_ignores = {}
         linter.safety_table.forced_safe = []
         linter.safety_table.forced_unsafe = []
-        linter.unresolved_target_version = 3.9
+        linter.unresolved_target_version = none
         linter.per_file_target_version = {}
         linter.preview = disabled
         linter.explicit_preview_rules = false
@@ -4963,30 +4999,34 @@ fn flake8_import_convention_invalid_aliases_config_module_name() -> Result<()> {
 
 #[test]
 fn flake8_import_convention_unused_aliased_import() {
-    assert_cmd_snapshot!(Command::new(get_cargo_bin(BIN_NAME))
-        .args(STDIN_BASE_OPTIONS)
-        .arg("--config")
-        .arg(r#"lint.isort.required-imports = ["import pandas"]"#)
-        .args(["--select", "I002,ICN001,F401"])
-        .args(["--stdin-filename", "test.py"])
-        .arg("--unsafe-fixes")
-        .arg("--fix")
-        .arg("-")
-        .pass_stdin("1"));
+    assert_cmd_snapshot!(
+        Command::new(get_cargo_bin(BIN_NAME))
+            .args(STDIN_BASE_OPTIONS)
+            .arg("--config")
+            .arg(r#"lint.isort.required-imports = ["import pandas"]"#)
+            .args(["--select", "I002,ICN001,F401"])
+            .args(["--stdin-filename", "test.py"])
+            .arg("--unsafe-fixes")
+            .arg("--fix")
+            .arg("-")
+            .pass_stdin("1")
+    );
 }
 
 #[test]
 fn flake8_import_convention_unused_aliased_import_no_conflict() {
-    assert_cmd_snapshot!(Command::new(get_cargo_bin(BIN_NAME))
-        .args(STDIN_BASE_OPTIONS)
-        .arg("--config")
-        .arg(r#"lint.isort.required-imports = ["import pandas as pd"]"#)
-        .args(["--select", "I002,ICN001,F401"])
-        .args(["--stdin-filename", "test.py"])
-        .arg("--unsafe-fixes")
-        .arg("--fix")
-        .arg("-")
-        .pass_stdin("1"));
+    assert_cmd_snapshot!(
+        Command::new(get_cargo_bin(BIN_NAME))
+            .args(STDIN_BASE_OPTIONS)
+            .arg("--config")
+            .arg(r#"lint.isort.required-imports = ["import pandas as pd"]"#)
+            .args(["--select", "I002,ICN001,F401"])
+            .args(["--stdin-filename", "test.py"])
+            .arg("--unsafe-fixes")
+            .arg("--fix")
+            .arg("-")
+            .pass_stdin("1")
+    );
 }
 
 // See: https://github.com/astral-sh/ruff/issues/16177
@@ -5620,3 +5660,34 @@ fn semantic_syntax_errors() -> Result<()> {
 
     Ok(())
 }
+
+/// Regression test for <https://github.com/astral-sh/ruff/issues/17821>.
+///
+/// `lint.typing-extensions = false` with Python 3.9 should disable the PYI019 lint because it would
+/// try to import `Self` from `typing_extensions`
+#[test]
+fn combine_typing_extensions_config() {
+    let contents = "
+from typing import TypeVar
+T = TypeVar('T')
+class Foo:
+    def f(self: T) -> T: ...
+";
+    assert_cmd_snapshot!(
+        Command::new(get_cargo_bin(BIN_NAME))
+            .args(STDIN_BASE_OPTIONS)
+            .args(["--config", "lint.typing-extensions = false"])
+            .arg("--select=PYI019")
+            .arg("--target-version=py39")
+            .arg("-")
+            .pass_stdin(contents),
+        @r"
+    success: true
+    exit_code: 0
+    ----- stdout -----
+    All checks passed!
+
+    ----- stderr -----
+    "
+    );
+}

crates/ruff/tests/snapshots/integration_test__rule_f401.snap

@@ -5,7 +5,6 @@ info:
   args:
     - rule
     - F401
-snapshot_kind: text
 ---
 success: true
 exit_code: 0
@@ -84,6 +83,11 @@ else:
     print("numpy is not installed")
 ```
 
+## Preview
+When [preview](https://docs.astral.sh/ruff/preview/) is enabled,
+the criterion for determining whether an import is first-party
+is stricter, which could affect the suggested fix. See [this FAQ section](https://docs.astral.sh/ruff/faq/#how-does-ruff-determine-which-of-my-imports-are-first-party-third-party-etc) for more details.
+
 ## Options
 - `lint.ignore-init-module-imports`
 - `lint.pyflakes.allowed-unused-imports`

crates/ruff_annotate_snippets/src/renderer/display_list.rs

@@ -32,7 +32,7 @@
 //!
 //! The above snippet has been built out of the following structure:
 use crate::snippet;
-use std::cmp::{max, min, Reverse};
+use std::cmp::{Reverse, max, min};
 use std::collections::HashMap;
 use std::fmt::Display;
 use std::ops::Range;
@@ -41,7 +41,7 @@ use std::{cmp, fmt};
 use unicode_width::UnicodeWidthStr;
 
 use crate::renderer::styled_buffer::StyledBuffer;
-use crate::renderer::{stylesheet::Stylesheet, Margin, Style, DEFAULT_TERM_WIDTH};
+use crate::renderer::{DEFAULT_TERM_WIDTH, Margin, Style, stylesheet::Stylesheet};
 
 const ANONYMIZED_LINE_NUM: &str = "LL";
 const ERROR_TXT: &str = "error";
@@ -1273,10 +1273,7 @@ fn fold_body(body: Vec<DisplayLine<'_>>) -> Vec<DisplayLine<'_>> {
                             let inline_marks = lines
                                 .last()
                                 .and_then(|line| {
-                                    if let DisplayLine::Source {
-                                        ref inline_marks, ..
-                                    } = line
-                                    {
+                                    if let DisplayLine::Source { inline_marks, .. } = line {
                                         let inline_marks = inline_marks.clone();
                                         Some(inline_marks)
                                     } else {

crates/ruff_annotate_snippets/tests/fixtures/main.rs

@@ -2,8 +2,8 @@ mod deserialize;
 
 use crate::deserialize::Fixture;
 use ruff_annotate_snippets::{Message, Renderer};
-use snapbox::data::DataFormat;
 use snapbox::Data;
+use snapbox::data::DataFormat;
 use std::error::Error;
 
 fn main() {

crates/ruff_benchmark/Cargo.toml

@@ -33,7 +33,7 @@ name = "formatter"
 harness = false
 
 [[bench]]
-name = "red_knot"
+name = "ty"
 harness = false
 
 [dependencies]
@@ -49,7 +49,7 @@ ruff_python_ast = { workspace = true }
 ruff_python_formatter = { workspace = true }
 ruff_python_parser = { workspace = true }
 ruff_python_trivia = { workspace = true }
-red_knot_project = { workspace = true }
+ty_project = { workspace = true }
 
 [lints]
 workspace = true

crates/ruff_benchmark/benches/formatter.rs

@@ -1,14 +1,14 @@
 use std::path::Path;
 
 use ruff_benchmark::criterion::{
-    criterion_group, criterion_main, BenchmarkId, Criterion, Throughput,
+    BenchmarkId, Criterion, Throughput, criterion_group, criterion_main,
 };
 
 use ruff_benchmark::{
-    TestCase, LARGE_DATASET, NUMPY_CTYPESLIB, NUMPY_GLOBALS, PYDANTIC_TYPES, UNICODE_PYPINYIN,
+    LARGE_DATASET, NUMPY_CTYPESLIB, NUMPY_GLOBALS, PYDANTIC_TYPES, TestCase, UNICODE_PYPINYIN,
 };
-use ruff_python_formatter::{format_module_ast, PreviewMode, PyFormatOptions};
-use ruff_python_parser::{parse, Mode, ParseOptions};
+use ruff_python_formatter::{PreviewMode, PyFormatOptions, format_module_ast};
+use ruff_python_parser::{Mode, ParseOptions, parse};
 use ruff_python_trivia::CommentRanges;
 
 #[cfg(target_os = "windows")]

crates/ruff_benchmark/benches/lexer.rs

@@ -1,12 +1,12 @@
 use ruff_benchmark::criterion;
 
 use criterion::{
-    criterion_group, criterion_main, measurement::WallTime, BenchmarkId, Criterion, Throughput,
+    BenchmarkId, Criterion, Throughput, criterion_group, criterion_main, measurement::WallTime,
 };
 use ruff_benchmark::{
-    TestCase, LARGE_DATASET, NUMPY_CTYPESLIB, NUMPY_GLOBALS, PYDANTIC_TYPES, UNICODE_PYPINYIN,
+    LARGE_DATASET, NUMPY_CTYPESLIB, NUMPY_GLOBALS, PYDANTIC_TYPES, TestCase, UNICODE_PYPINYIN,
 };
-use ruff_python_parser::{lexer, Mode, TokenKind};
+use ruff_python_parser::{Mode, TokenKind, lexer};
 
 #[cfg(target_os = "windows")]
 #[global_allocator]

crates/ruff_benchmark/benches/linter.rs

@@ -1,18 +1,18 @@
 use ruff_benchmark::criterion;
 
 use criterion::{
-    criterion_group, criterion_main, BenchmarkGroup, BenchmarkId, Criterion, Throughput,
+    BenchmarkGroup, BenchmarkId, Criterion, Throughput, criterion_group, criterion_main,
 };
 use ruff_benchmark::{
-    TestCase, LARGE_DATASET, NUMPY_CTYPESLIB, NUMPY_GLOBALS, PYDANTIC_TYPES, UNICODE_PYPINYIN,
+    LARGE_DATASET, NUMPY_CTYPESLIB, NUMPY_GLOBALS, PYDANTIC_TYPES, TestCase, UNICODE_PYPINYIN,
 };
-use ruff_linter::linter::{lint_only, ParseSource};
+use ruff_linter::linter::{ParseSource, lint_only};
 use ruff_linter::rule_selector::PreviewOptions;
 use ruff_linter::settings::rule_table::RuleTable;
 use ruff_linter::settings::types::PreviewMode;
-use ruff_linter::settings::{flags, LinterSettings};
+use ruff_linter::settings::{LinterSettings, flags};
 use ruff_linter::source_kind::SourceKind;
-use ruff_linter::{registry::Rule, RuleSelector};
+use ruff_linter::{RuleSelector, registry::Rule};
 use ruff_python_ast::PySourceType;
 use ruff_python_parser::parse_module;
 
@@ -45,9 +45,9 @@ static GLOBAL: tikv_jemallocator::Jemalloc = tikv_jemallocator::Jemalloc;
         target_arch = "powerpc64"
     )
 ))]
-#[allow(non_upper_case_globals)]
-#[export_name = "_rjem_malloc_conf"]
-#[allow(unsafe_code)]
+#[unsafe(export_name = "_rjem_malloc_conf")]
+#[expect(non_upper_case_globals)]
+#[expect(unsafe_code)]
 pub static _rjem_malloc_conf: &[u8] = b"dirty_decay_ms:-1,muzzy_decay_ms:-1\0";
 
 fn create_test_cases() -> Vec<TestCase> {

crates/ruff_benchmark/benches/parser.rs

@@ -1,13 +1,13 @@
 use ruff_benchmark::criterion;
 
 use criterion::{
-    criterion_group, criterion_main, measurement::WallTime, BenchmarkId, Criterion, Throughput,
+    BenchmarkId, Criterion, Throughput, criterion_group, criterion_main, measurement::WallTime,
 };
 use ruff_benchmark::{
-    TestCase, LARGE_DATASET, NUMPY_CTYPESLIB, NUMPY_GLOBALS, PYDANTIC_TYPES, UNICODE_PYPINYIN,
+    LARGE_DATASET, NUMPY_CTYPESLIB, NUMPY_GLOBALS, PYDANTIC_TYPES, TestCase, UNICODE_PYPINYIN,
 };
-use ruff_python_ast::statement_visitor::{walk_stmt, StatementVisitor};
 use ruff_python_ast::Stmt;
+use ruff_python_ast::statement_visitor::{StatementVisitor, walk_stmt};
 use ruff_python_parser::parse_module;
 
 #[cfg(target_os = "windows")]

crates/ruff_benchmark/benches/ty.rs

@@ -3,20 +3,20 @@ use ruff_benchmark::criterion;
 
 use std::ops::Range;
 
-use criterion::{criterion_group, criterion_main, BatchSize, Criterion};
+use criterion::{BatchSize, Criterion, criterion_group, criterion_main};
 use rayon::ThreadPoolBuilder;
 use rustc_hash::FxHashSet;
 
-use red_knot_project::metadata::options::{EnvironmentOptions, Options};
-use red_knot_project::metadata::value::RangedValue;
-use red_knot_project::watch::{ChangeEvent, ChangedKind};
-use red_knot_project::{Db, ProjectDatabase, ProjectMetadata};
 use ruff_benchmark::TestFile;
 use ruff_db::diagnostic::{Diagnostic, DiagnosticId, Severity};
-use ruff_db::files::{system_path_to_file, File};
+use ruff_db::files::{File, system_path_to_file};
 use ruff_db::source::source_text;
 use ruff_db::system::{MemoryFileSystem, SystemPath, SystemPathBuf, TestSystem};
 use ruff_python_ast::PythonVersion;
+use ty_project::metadata::options::{EnvironmentOptions, Options};
+use ty_project::metadata::value::RangedValue;
+use ty_project::watch::{ChangeEvent, ChangedKind};
+use ty_project::{Db, ProjectDatabase, ProjectMetadata};
 
 struct Case {
     db: ProjectDatabase,
@@ -59,13 +59,7 @@ type KeyDiagnosticFields = (
     Severity,
 );
 
-static EXPECTED_TOMLLIB_DIAGNOSTICS: &[KeyDiagnosticFields] = &[(
-    DiagnosticId::lint("unused-ignore-comment"),
-    Some("/src/tomllib/_parser.py"),
-    Some(22299..22333),
-    "Unused blanket `type: ignore` directive",
-    Severity::Warning,
-)];
+static EXPECTED_TOMLLIB_DIAGNOSTICS: &[KeyDiagnosticFields] = &[];
 
 fn tomllib_path(file: &TestFile) -> SystemPathBuf {
     SystemPathBuf::from("src").join(file.name())
@@ -122,7 +116,7 @@ static RAYON_INITIALIZED: std::sync::Once = std::sync::Once::new();
 fn setup_rayon() {
     // Initialize the rayon thread pool outside the benchmark because it has a significant cost.
     // We limit the thread pool to only one (the current thread) because we're focused on
-    // where red knot spends time and less about how well the code runs concurrently.
+    // where ty spends time and less about how well the code runs concurrently.
     // We might want to add a benchmark focusing on concurrency to detect congestion in the future.
     RAYON_INITIALIZED.call_once(|| {
         ThreadPoolBuilder::new()
@@ -172,7 +166,7 @@ fn benchmark_incremental(criterion: &mut Criterion) {
 
     setup_rayon();
 
-    criterion.bench_function("red_knot_check_file[incremental]", |b| {
+    criterion.bench_function("ty_check_file[incremental]", |b| {
         b.iter_batched_ref(setup, incremental, BatchSize::SmallInput);
     });
 }
@@ -180,7 +174,7 @@ fn benchmark_incremental(criterion: &mut Criterion) {
 fn benchmark_cold(criterion: &mut Criterion) {
     setup_rayon();
 
-    criterion.bench_function("red_knot_check_file[cold]", |b| {
+    criterion.bench_function("ty_check_file[cold]", |b| {
         b.iter_batched_ref(
             setup_tomllib_case,
             |case| {
@@ -203,7 +197,7 @@ fn assert_diagnostics(db: &dyn Db, diagnostics: &[Diagnostic], expected: &[KeyDi
                 diagnostic.id(),
                 diagnostic
                     .primary_span()
-                    .map(|span| span.file())
+                    .map(|span| span.expect_ty_file())
                     .map(|file| file.path(db).as_str()),
                 diagnostic
                     .primary_span()
@@ -257,7 +251,7 @@ fn setup_micro_case(code: &str) -> Case {
 fn benchmark_many_string_assignments(criterion: &mut Criterion) {
     setup_rayon();
 
-    criterion.bench_function("red_knot_micro[many_string_assignments]", |b| {
+    criterion.bench_function("ty_micro[many_string_assignments]", |b| {
         b.iter_batched_ref(
             || {
                 // This is a micro benchmark, but it is effectively identical to a code sample
@@ -307,6 +301,56 @@ fn benchmark_many_string_assignments(criterion: &mut Criterion) {
     });
 }
 
+fn benchmark_many_tuple_assignments(criterion: &mut Criterion) {
+    setup_rayon();
+
+    criterion.bench_function("ty_micro[many_tuple_assignments]", |b| {
+        b.iter_batched_ref(
+            || {
+                // This is a micro benchmark, but it is effectively identical to a code sample
+                // observed in https://github.com/astral-sh/ty/issues/362
+                setup_micro_case(
+                    r#"
+                    def flag() -> bool:
+                        return True
+
+                    t = ()
+                    if flag():
+                        t += (1,)
+                    if flag():
+                        t += (2,)
+                    if flag():
+                        t += (3,)
+                    if flag():
+                        t += (4,)
+                    if flag():
+                        t += (5,)
+                    if flag():
+                        t += (6,)
+                    if flag():
+                        t += (7,)
+                    if flag():
+                        t += (8,)
+
+                    # Perform some kind of operation on the union type
+                    print(1 in t)
+                    "#,
+                )
+            },
+            |case| {
+                let Case { db, .. } = case;
+                let result = db.check().unwrap();
+                assert_eq!(result.len(), 0);
+            },
+            BatchSize::SmallInput,
+        );
+    });
+}
+
 criterion_group!(check_file, benchmark_cold, benchmark_incremental);
-criterion_group!(micro, benchmark_many_string_assignments);
+criterion_group!(
+    micro,
+    benchmark_many_string_assignments,
+    benchmark_many_tuple_assignments
+);
 criterion_main!(check_file, micro);

crates/ruff_cache/src/cache_key.rs

@@ -2,8 +2,8 @@ use std::borrow::Cow;
 use std::collections::{BTreeMap, BTreeSet, HashMap, HashSet};
 use std::hash::{Hash, Hasher};
 use std::num::{
-    NonZeroI128, NonZeroI16, NonZeroI32, NonZeroI64, NonZeroI8, NonZeroU128, NonZeroU16,
-    NonZeroU32, NonZeroU64, NonZeroU8,
+    NonZeroI8, NonZeroI16, NonZeroI32, NonZeroI64, NonZeroI128, NonZeroU8, NonZeroU16, NonZeroU32,
+    NonZeroU64, NonZeroU128,
 };
 use std::path::{Path, PathBuf};
 
@@ -213,7 +213,7 @@ macro_rules! impl_cache_key_tuple {
 
     ( $($name:ident)+) => (
         impl<$($name: CacheKey),+> CacheKey for ($($name,)+) where last_type!($($name,)+): ?Sized {
-            #[allow(non_snake_case)]
+            #[expect(non_snake_case)]
             #[inline]
             fn cache_key(&self, state: &mut CacheKeyHasher) {
                 let ($(ref $name,)+) = *self;

crates/ruff_cache/tests/cache_key.rs

@@ -47,7 +47,7 @@ fn struct_ignored_fields() {
     struct NamedFieldsStruct {
         a: String,
         #[cache_key(ignore)]
-        #[allow(unused)]
+        #[expect(unused)]
         b: String,
     }
 

crates/ruff_db/Cargo.toml

@@ -36,7 +36,6 @@ path-slash = { workspace = true }
 thiserror = { workspace = true }
 tracing = { workspace = true }
 tracing-subscriber = { workspace = true, optional = true }
-tracing-tree = { workspace = true, optional = true }
 rustc-hash = { workspace = true }
 zip = { workspace = true }
 
@@ -55,4 +54,4 @@ cache = ["ruff_cache"]
 os = ["ignore", "dep:etcetera"]
 serde = ["dep:serde", "camino/serde1"]
 # Exposes testing utilities.
-testing = ["tracing-subscriber", "tracing-tree"]
+testing = ["tracing-subscriber"]

crates/ruff_db/src/diagnostic/mod.rs

@@ -1,15 +1,14 @@
 use std::{fmt::Formatter, sync::Arc};
 
-use thiserror::Error;
+use render::{FileResolver, Input};
+use ruff_source_file::{SourceCode, SourceFile};
 
 use ruff_annotate_snippets::Level as AnnotateLevel;
 use ruff_text_size::{Ranged, TextRange};
 
 pub use self::render::DisplayDiagnostic;
-use crate::files::File;
-use crate::Db;
+use crate::{Db, files::File};
 
-use self::render::FileResolver;
 mod render;
 mod stylesheet;
 
@@ -115,10 +114,9 @@ impl Diagnostic {
     /// callers should prefer using this with `write!` instead of `writeln!`.
     pub fn display<'a>(
         &'a self,
-        db: &'a dyn Db,
+        resolver: &'a dyn FileResolver,
         config: &'a DisplayDiagnosticConfig,
     ) -> DisplayDiagnostic<'a> {
-        let resolver = FileResolver::new(db);
         DisplayDiagnostic::new(resolver, config, self)
     }
 
@@ -134,20 +132,20 @@ impl Diagnostic {
     /// NOTE: At present, this routine will return the first primary
     /// annotation's message as the primary message when the main diagnostic
     /// message is empty. This is meant to facilitate an incremental migration
-    /// in Red Knot over to the new diagnostic data model. (The old data model
+    /// in ty over to the new diagnostic data model. (The old data model
     /// didn't distinguish between messages on the entire diagnostic and
     /// messages attached to a particular span.)
     pub fn primary_message(&self) -> &str {
         if !self.inner.message.as_str().is_empty() {
             return self.inner.message.as_str();
         }
-        // FIXME: As a special case, while we're migrating Red Knot
+        // FIXME: As a special case, while we're migrating ty
         // to the new diagnostic data model, we'll look for a primary
         // message from the primary annotation. This is because most
-        // Red Knot diagnostics are created with an empty diagnostic
+        // ty diagnostics are created with an empty diagnostic
         // message and instead attach the message to the annotation.
         // Fixing this will require touching basically every diagnostic
-        // in Red Knot, so we do it this way for now to match the old
+        // in ty, so we do it this way for now to match the old
         // semantics. ---AG
         self.primary_annotation()
             .and_then(|ann| ann.get_message())
@@ -165,7 +163,7 @@ impl Diagnostic {
     ///
     /// The reason why we don't just always return both the main diagnostic
     /// message and the primary annotation message is because this was written
-    /// in the midst of an incremental migration of Red Knot over to the new
+    /// in the midst of an incremental migration of ty over to the new
     /// diagnostic data model. At time of writing, diagnostics were still
     /// constructed in the old model where the main diagnostic message and the
     /// primary annotation message were not distinguished from each other. So
@@ -227,6 +225,49 @@ impl Diagnostic {
     pub fn primary_span(&self) -> Option<Span> {
         self.primary_annotation().map(|ann| ann.span.clone())
     }
+
+    /// Returns the tags from the primary annotation of this diagnostic if it exists.
+    pub fn primary_tags(&self) -> Option<&[DiagnosticTag]> {
+        self.primary_annotation().map(|ann| ann.tags.as_slice())
+    }
+
+    /// Returns the "primary" span of this diagnostic, panicking if it does not exist.
+    ///
+    /// This should typically only be used when working with diagnostics in Ruff, where diagnostics
+    /// are currently required to have a primary span.
+    ///
+    /// See [`Diagnostic::primary_span`] for more details.
+    pub fn expect_primary_span(&self) -> Span {
+        self.primary_span().expect("Expected a primary span")
+    }
+
+    /// Returns a key that can be used to sort two diagnostics into the canonical order
+    /// in which they should appear when rendered.
+    pub fn rendering_sort_key<'a>(&'a self, db: &'a dyn Db) -> impl Ord + 'a {
+        RenderingSortKey {
+            db,
+            diagnostic: self,
+        }
+    }
+
+    /// Returns all annotations, skipping the first primary annotation.
+    pub fn secondary_annotations(&self) -> impl Iterator<Item = &Annotation> {
+        let mut seen_primary = false;
+        self.inner.annotations.iter().filter(move |ann| {
+            if seen_primary {
+                true
+            } else if ann.is_primary {
+                seen_primary = true;
+                false
+            } else {
+                true
+            }
+        })
+    }
+
+    pub fn sub_diagnostics(&self) -> &[SubDiagnostic] {
+        &self.inner.subs
+    }
 }
 
 #[derive(Debug, Clone, Eq, PartialEq)]
@@ -238,6 +279,60 @@ struct DiagnosticInner {
     subs: Vec<SubDiagnostic>,
 }
 
+struct RenderingSortKey<'a> {
+    db: &'a dyn Db,
+    diagnostic: &'a Diagnostic,
+}
+
+impl Ord for RenderingSortKey<'_> {
+    // We sort diagnostics in a way that keeps them in source order
+    // and grouped by file. After that, we fall back to severity
+    // (with fatal messages sorting before info messages) and then
+    // finally the diagnostic ID.
+    fn cmp(&self, other: &Self) -> std::cmp::Ordering {
+        if let (Some(span1), Some(span2)) = (
+            self.diagnostic.primary_span(),
+            other.diagnostic.primary_span(),
+        ) {
+            let order = span1.file().path(&self.db).cmp(span2.file().path(&self.db));
+            if order.is_ne() {
+                return order;
+            }
+
+            if let (Some(range1), Some(range2)) = (span1.range(), span2.range()) {
+                let order = range1.start().cmp(&range2.start());
+                if order.is_ne() {
+                    return order;
+                }
+            }
+        }
+        // Reverse so that, e.g., Fatal sorts before Info.
+        let order = self
+            .diagnostic
+            .severity()
+            .cmp(&other.diagnostic.severity())
+            .reverse();
+        if order.is_ne() {
+            return order;
+        }
+        self.diagnostic.id().cmp(&other.diagnostic.id())
+    }
+}
+
+impl PartialOrd for RenderingSortKey<'_> {
+    fn partial_cmp(&self, other: &Self) -> Option<std::cmp::Ordering> {
+        Some(self.cmp(other))
+    }
+}
+
+impl PartialEq for RenderingSortKey<'_> {
+    fn eq(&self, other: &Self) -> bool {
+        self.cmp(other).is_eq()
+    }
+}
+
+impl Eq for RenderingSortKey<'_> {}
+
 /// A collection of information subservient to a diagnostic.
 ///
 /// A sub-diagnostic is always rendered after the parent diagnostic it is
@@ -295,6 +390,57 @@ impl SubDiagnostic {
     pub fn annotate(&mut self, ann: Annotation) {
         self.inner.annotations.push(ann);
     }
+
+    pub fn annotations(&self) -> &[Annotation] {
+        &self.inner.annotations
+    }
+
+    /// Returns a shared borrow of the "primary" annotation of this diagnostic
+    /// if one exists.
+    ///
+    /// When there are multiple primary annotations, then the first one that
+    /// was added to this diagnostic is returned.
+    pub fn primary_annotation(&self) -> Option<&Annotation> {
+        self.inner.annotations.iter().find(|ann| ann.is_primary)
+    }
+
+    /// Introspects this diagnostic and returns what kind of "primary" message
+    /// it contains for concise formatting.
+    ///
+    /// When we concisely format diagnostics, we likely want to not only
+    /// include the primary diagnostic message but also the message attached
+    /// to the primary annotation. In particular, the primary annotation often
+    /// contains *essential* information or context for understanding the
+    /// diagnostic.
+    ///
+    /// The reason why we don't just always return both the main diagnostic
+    /// message and the primary annotation message is because this was written
+    /// in the midst of an incremental migration of ty over to the new
+    /// diagnostic data model. At time of writing, diagnostics were still
+    /// constructed in the old model where the main diagnostic message and the
+    /// primary annotation message were not distinguished from each other. So
+    /// for now, we carefully return what kind of messages this diagnostic
+    /// contains. In effect, if this diagnostic has a non-empty main message
+    /// *and* a non-empty primary annotation message, then the diagnostic is
+    /// 100% using the new diagnostic data model and we can format things
+    /// appropriately.
+    ///
+    /// The type returned implements the `std::fmt::Display` trait. In most
+    /// cases, just converting it to a string (or printing it) will do what
+    /// you want.
+    pub fn concise_message(&self) -> ConciseMessage {
+        let main = self.inner.message.as_str();
+        let annotation = self
+            .primary_annotation()
+            .and_then(|ann| ann.get_message())
+            .unwrap_or_default();
+        match (main.is_empty(), annotation.is_empty()) {
+            (false, true) => ConciseMessage::MainDiagnostic(main),
+            (true, false) => ConciseMessage::PrimaryAnnotation(annotation),
+            (false, false) => ConciseMessage::Both { main, annotation },
+            (true, true) => ConciseMessage::Empty,
+        }
+    }
 }
 
 #[derive(Debug, Clone, Eq, PartialEq)]
@@ -338,6 +484,8 @@ pub struct Annotation {
     /// Whether this annotation is "primary" or not. When it isn't primary, an
     /// annotation is said to be "secondary."
     is_primary: bool,
+    /// The diagnostic tags associated with this annotation.
+    tags: Vec<DiagnosticTag>,
 }
 
 impl Annotation {
@@ -355,6 +503,7 @@ impl Annotation {
             span,
             message: None,
             is_primary: true,
+            tags: Vec::new(),
         }
     }
 
@@ -370,6 +519,7 @@ impl Annotation {
             span,
             message: None,
             is_primary: false,
+            tags: Vec::new(),
         }
     }
 
@@ -412,6 +562,41 @@ impl Annotation {
     pub fn get_span(&self) -> &Span {
         &self.span
     }
+
+    /// Sets the span on this annotation.
+    pub fn set_span(&mut self, span: Span) {
+        self.span = span;
+    }
+
+    /// Returns the tags associated with this annotation.
+    pub fn get_tags(&self) -> &[DiagnosticTag] {
+        &self.tags
+    }
+
+    /// Attaches this tag to this annotation.
+    ///
+    /// It will not replace any existing tags.
+    pub fn tag(mut self, tag: DiagnosticTag) -> Annotation {
+        self.tags.push(tag);
+        self
+    }
+
+    /// Attaches an additional tag to this annotation.
+    pub fn push_tag(&mut self, tag: DiagnosticTag) {
+        self.tags.push(tag);
+    }
+}
+
+/// Tags that can be associated with an annotation.
+///
+/// These tags are used to provide additional information about the annotation.
+/// and are passed through to the language server protocol.
+#[derive(Debug, Clone, Eq, PartialEq)]
+pub enum DiagnosticTag {
+    /// Unused or unnecessary code. Used for unused parameters, unreachable code, etc.
+    Unnecessary,
+    /// Deprecated or obsolete code.
+    Deprecated,
 }
 
 /// A string identifier for a lint rule.
@@ -502,62 +687,84 @@ impl DiagnosticId {
         code.split_once(':').map(|(_, rest)| rest)
     }
 
-    /// Returns `true` if this `DiagnosticId` matches the given name.
+    /// Returns a concise description of this diagnostic ID.
     ///
-    /// ## Examples
-    /// ```
-    /// use ruff_db::diagnostic::DiagnosticId;
-    ///
-    /// assert!(DiagnosticId::Io.matches("io"));
-    /// assert!(DiagnosticId::lint("test").matches("lint:test"));
-    /// assert!(!DiagnosticId::lint("test").matches("test"));
-    /// ```
-    pub fn matches(&self, expected_name: &str) -> bool {
-        match self.as_str() {
-            Ok(id) => id == expected_name,
-            Err(DiagnosticAsStrError::Category { category, name }) => expected_name
-                .strip_prefix(category)
-                .and_then(|prefix| prefix.strip_prefix(":"))
-                .is_some_and(|rest| rest == name),
-        }
-    }
-
-    pub fn as_str(&self) -> Result<&str, DiagnosticAsStrError> {
-        Ok(match self {
+    /// Note that this doesn't include the lint's category. It
+    /// only includes the lint's name.
+    pub fn as_str(&self) -> &'static str {
+        match self {
             DiagnosticId::Panic => "panic",
             DiagnosticId::Io => "io",
             DiagnosticId::InvalidSyntax => "invalid-syntax",
-            DiagnosticId::Lint(name) => {
-                return Err(DiagnosticAsStrError::Category {
-                    category: "lint",
-                    name: name.as_str(),
-                })
-            }
+            DiagnosticId::Lint(name) => name.as_str(),
             DiagnosticId::RevealedType => "revealed-type",
             DiagnosticId::UnknownRule => "unknown-rule",
-        })
+        }
     }
-}
 
-#[derive(Copy, Clone, Debug, Eq, PartialEq, Error)]
-pub enum DiagnosticAsStrError {
-    /// The id can't be converted to a string because it belongs to a sub-category.
-    #[error("id from a sub-category: {category}:{name}")]
-    Category {
-        /// The id's category.
-        category: &'static str,
-        /// The diagnostic id in this category.
-        name: &'static str,
-    },
+    pub fn is_invalid_syntax(&self) -> bool {
+        matches!(self, Self::InvalidSyntax)
+    }
 }
 
 impl std::fmt::Display for DiagnosticId {
     fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
-        match self.as_str() {
-            Ok(name) => f.write_str(name),
-            Err(DiagnosticAsStrError::Category { category, name }) => {
-                write!(f, "{category}:{name}")
-            }
+        write!(f, "{}", self.as_str())
+    }
+}
+
+/// A unified file representation for both ruff and ty.
+///
+/// Such a representation is needed for rendering [`Diagnostic`]s that can optionally contain
+/// [`Annotation`]s with [`Span`]s that need to refer to the text of a file. However, ty and ruff
+/// use very different file types: a `Copy`-able salsa-interned [`File`], and a heavier-weight
+/// [`SourceFile`], respectively.
+///
+/// This enum presents a unified interface to these two types for the sake of creating [`Span`]s and
+/// emitting diagnostics from both ty and ruff.
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub enum UnifiedFile {
+    Ty(File),
+    Ruff(SourceFile),
+}
+
+impl UnifiedFile {
+    pub fn path<'a>(&'a self, resolver: &'a dyn FileResolver) -> &'a str {
+        match self {
+            UnifiedFile::Ty(file) => resolver.path(*file),
+            UnifiedFile::Ruff(file) => file.name(),
+        }
+    }
+
+    fn diagnostic_source(&self, resolver: &dyn FileResolver) -> DiagnosticSource {
+        match self {
+            UnifiedFile::Ty(file) => DiagnosticSource::Ty(resolver.input(*file)),
+            UnifiedFile::Ruff(file) => DiagnosticSource::Ruff(file.clone()),
+        }
+    }
+}
+
+/// A unified wrapper for types that can be converted to a [`SourceCode`].
+///
+/// As with [`UnifiedFile`], ruff and ty use slightly different representations for source code.
+/// [`DiagnosticSource`] wraps both of these and provides the single
+/// [`DiagnosticSource::as_source_code`] method to produce a [`SourceCode`] with the appropriate
+/// lifetimes.
+///
+/// See [`UnifiedFile::diagnostic_source`] for a way to obtain a [`DiagnosticSource`] from a file
+/// and [`FileResolver`].
+#[derive(Clone, Debug)]
+enum DiagnosticSource {
+    Ty(Input),
+    Ruff(SourceFile),
+}
+
+impl DiagnosticSource {
+    /// Returns this input as a `SourceCode` for convenient querying.
+    fn as_source_code(&self) -> SourceCode {
+        match self {
+            DiagnosticSource::Ty(input) => SourceCode::new(input.text.as_str(), &input.line_index),
+            DiagnosticSource::Ruff(source) => SourceCode::new(source.source_text(), source.index()),
         }
     }
 }
@@ -569,14 +776,14 @@ impl std::fmt::Display for DiagnosticId {
 /// the entire file. For example, when the file should be executable but isn't.
 #[derive(Debug, Clone, PartialEq, Eq)]
 pub struct Span {
-    file: File,
+    file: UnifiedFile,
     range: Option<TextRange>,
 }
 
 impl Span {
-    /// Returns the `File` attached to this `Span`.
-    pub fn file(&self) -> File {
-        self.file
+    /// Returns the `UnifiedFile` attached to this `Span`.
+    pub fn file(&self) -> &UnifiedFile {
+        &self.file
     }
 
     /// Returns the range, if available, attached to this `Span`.
@@ -597,10 +804,38 @@ impl Span {
     pub fn with_optional_range(self, range: Option<TextRange>) -> Span {
         Span { range, ..self }
     }
+
+    /// Returns the [`File`] attached to this [`Span`].
+    ///
+    /// Panics if the file is a [`UnifiedFile::Ruff`] instead of a [`UnifiedFile::Ty`].
+    pub fn expect_ty_file(&self) -> File {
+        match self.file {
+            UnifiedFile::Ty(file) => file,
+            UnifiedFile::Ruff(_) => panic!("Expected a ty `File`, found a ruff `SourceFile`"),
+        }
+    }
+
+    /// Returns the [`SourceFile`] attached to this [`Span`].
+    ///
+    /// Panics if the file is a [`UnifiedFile::Ty`] instead of a [`UnifiedFile::Ruff`].
+    pub fn expect_ruff_file(&self) -> &SourceFile {
+        match &self.file {
+            UnifiedFile::Ty(_) => panic!("Expected a ruff `SourceFile`, found a ty `File`"),
+            UnifiedFile::Ruff(file) => file,
+        }
+    }
 }
 
 impl From<File> for Span {
     fn from(file: File) -> Span {
+        let file = UnifiedFile::Ty(file);
+        Span { file, range: None }
+    }
+}
+
+impl From<SourceFile> for Span {
+    fn from(file: SourceFile) -> Self {
+        let file = UnifiedFile::Ruff(file);
         Span { file, range: None }
     }
 }
@@ -635,6 +870,10 @@ impl Severity {
             Severity::Fatal => AnnotateLevel::Error,
         }
     }
+
+    pub const fn is_fatal(self) -> bool {
+        matches!(self, Severity::Fatal)
+    }
 }
 
 /// Configuration for rendering diagnostics.

crates/ruff_db/src/diagnostic/render.rs

@@ -7,16 +7,17 @@ use ruff_annotate_snippets::{
 use ruff_source_file::{LineIndex, OneIndexed, SourceCode};
 use ruff_text_size::{TextRange, TextSize};
 
-use crate::diagnostic::stylesheet::{fmt_styled, DiagnosticStylesheet};
+use crate::diagnostic::stylesheet::{DiagnosticStylesheet, fmt_styled};
 use crate::{
-    files::File,
-    source::{line_index, source_text, SourceText},
-    system::SystemPath,
     Db,
+    files::File,
+    source::{SourceText, line_index, source_text},
+    system::SystemPath,
 };
 
 use super::{
-    Annotation, Diagnostic, DiagnosticFormat, DisplayDiagnosticConfig, Severity, SubDiagnostic,
+    Annotation, Diagnostic, DiagnosticFormat, DiagnosticSource, DisplayDiagnosticConfig, Severity,
+    SubDiagnostic,
 };
 
 /// A type that implements `std::fmt::Display` for diagnostic rendering.
@@ -30,17 +31,16 @@ use super::{
 ///   values. When using Salsa, this most commonly corresponds to the lifetime
 ///   of a Salsa `Db`.
 /// * The lifetime of the diagnostic being rendered.
-#[derive(Debug)]
 pub struct DisplayDiagnostic<'a> {
     config: &'a DisplayDiagnosticConfig,
-    resolver: FileResolver<'a>,
+    resolver: &'a dyn FileResolver,
     annotate_renderer: AnnotateRenderer,
     diag: &'a Diagnostic,
 }
 
 impl<'a> DisplayDiagnostic<'a> {
     pub(crate) fn new(
-        resolver: FileResolver<'a>,
+        resolver: &'a dyn FileResolver,
         config: &'a DisplayDiagnosticConfig,
         diag: &'a Diagnostic,
     ) -> DisplayDiagnostic<'a> {
@@ -86,11 +86,13 @@ impl std::fmt::Display for DisplayDiagnostic<'_> {
                 write!(
                     f,
                     " {path}",
-                    path = fmt_styled(self.resolver.path(span.file()), stylesheet.emphasis)
+                    path = fmt_styled(span.file().path(self.resolver), stylesheet.emphasis)
                 )?;
                 if let Some(range) = span.range() {
-                    let input = self.resolver.input(span.file());
-                    let start = input.as_source_code().line_column(range.start());
+                    let diagnostic_source = span.file().diagnostic_source(self.resolver);
+                    let start = diagnostic_source
+                        .as_source_code()
+                        .line_column(range.start());
 
                     write!(
                         f,
@@ -115,7 +117,7 @@ impl std::fmt::Display for DisplayDiagnostic<'_> {
             .emphasis(stylesheet.emphasis)
             .none(stylesheet.none);
 
-        let resolved = Resolved::new(&self.resolver, self.diag);
+        let resolved = Resolved::new(self.resolver, self.diag);
         let renderable = resolved.to_renderable(self.config.context);
         for diag in renderable.diagnostics.iter() {
             writeln!(f, "{}", renderer.render(diag.to_annotate()))?;
@@ -138,26 +140,23 @@ impl std::fmt::Display for DisplayDiagnostic<'_> {
 /// both.)
 #[derive(Debug)]
 struct Resolved<'a> {
-    id: String,
     diagnostics: Vec<ResolvedDiagnostic<'a>>,
 }
 
 impl<'a> Resolved<'a> {
     /// Creates a new resolved set of diagnostics.
-    fn new(resolver: &FileResolver<'a>, diag: &'a Diagnostic) -> Resolved<'a> {
+    fn new(resolver: &'a dyn FileResolver, diag: &'a Diagnostic) -> Resolved<'a> {
         let mut diagnostics = vec![];
         diagnostics.push(ResolvedDiagnostic::from_diagnostic(resolver, diag));
         for sub in &diag.inner.subs {
             diagnostics.push(ResolvedDiagnostic::from_sub_diagnostic(resolver, sub));
         }
-        let id = diag.inner.id.to_string();
-        Resolved { id, diagnostics }
+        Resolved { diagnostics }
     }
 
     /// Creates a value that is amenable to rendering directly.
     fn to_renderable(&self, context: usize) -> Renderable<'_> {
         Renderable {
-            id: &self.id,
             diagnostics: self
                 .diagnostics
                 .iter()
@@ -175,6 +174,7 @@ impl<'a> Resolved<'a> {
 #[derive(Debug)]
 struct ResolvedDiagnostic<'a> {
     severity: Severity,
+    id: Option<String>,
     message: String,
     annotations: Vec<ResolvedAnnotation<'a>>,
 }
@@ -182,7 +182,7 @@ struct ResolvedDiagnostic<'a> {
 impl<'a> ResolvedDiagnostic<'a> {
     /// Resolve a single diagnostic.
     fn from_diagnostic(
-        resolver: &FileResolver<'a>,
+        resolver: &'a dyn FileResolver,
         diag: &'a Diagnostic,
     ) -> ResolvedDiagnostic<'a> {
         let annotations: Vec<_> = diag
@@ -190,25 +190,16 @@ impl<'a> ResolvedDiagnostic<'a> {
             .annotations
             .iter()
             .filter_map(|ann| {
-                let path = resolver.path(ann.span.file);
-                let input = resolver.input(ann.span.file);
-                ResolvedAnnotation::new(path, &input, ann)
+                let path = ann.span.file.path(resolver);
+                let diagnostic_source = ann.span.file.diagnostic_source(resolver);
+                ResolvedAnnotation::new(path, &diagnostic_source, ann)
             })
             .collect();
-        let message = if diag.inner.message.as_str().is_empty() {
-            diag.inner.id.to_string()
-        } else {
-            // TODO: See the comment on `Renderable::id` for
-            // a plausible better idea than smushing the ID
-            // into the diagnostic message.
-            format!(
-                "{id}: {message}",
-                id = diag.inner.id,
-                message = diag.inner.message.as_str(),
-            )
-        };
+        let id = Some(diag.inner.id.to_string());
+        let message = diag.inner.message.as_str().to_string();
         ResolvedDiagnostic {
             severity: diag.inner.severity,
+            id,
             message,
             annotations,
         }
@@ -216,7 +207,7 @@ impl<'a> ResolvedDiagnostic<'a> {
 
     /// Resolve a single sub-diagnostic.
     fn from_sub_diagnostic(
-        resolver: &FileResolver<'a>,
+        resolver: &'a dyn FileResolver,
         diag: &'a SubDiagnostic,
     ) -> ResolvedDiagnostic<'a> {
         let annotations: Vec<_> = diag
@@ -224,13 +215,14 @@ impl<'a> ResolvedDiagnostic<'a> {
             .annotations
             .iter()
             .filter_map(|ann| {
-                let path = resolver.path(ann.span.file);
-                let input = resolver.input(ann.span.file);
-                ResolvedAnnotation::new(path, &input, ann)
+                let path = ann.span.file.path(resolver);
+                let diagnostic_source = ann.span.file.diagnostic_source(resolver);
+                ResolvedAnnotation::new(path, &diagnostic_source, ann)
             })
             .collect();
         ResolvedDiagnostic {
             severity: diag.inner.severity,
+            id: None,
             message: diag.inner.message.as_str().to_string(),
             annotations,
         }
@@ -259,10 +251,18 @@ impl<'a> ResolvedDiagnostic<'a> {
                     continue;
                 };
 
-                let prev_context_ends =
-                    context_after(&prev.input.as_source_code(), context, prev.line_end).get();
-                let this_context_begins =
-                    context_before(&ann.input.as_source_code(), context, ann.line_start).get();
+                let prev_context_ends = context_after(
+                    &prev.diagnostic_source.as_source_code(),
+                    context,
+                    prev.line_end,
+                )
+                .get();
+                let this_context_begins = context_before(
+                    &ann.diagnostic_source.as_source_code(),
+                    context,
+                    ann.line_start,
+                )
+                .get();
                 // The boundary case here is when `prev_context_ends`
                 // is exactly one less than `this_context_begins`. In
                 // that case, the context windows are adajcent and we
@@ -289,6 +289,7 @@ impl<'a> ResolvedDiagnostic<'a> {
             .sort_by(|snips1, snips2| snips1.has_primary.cmp(&snips2.has_primary).reverse());
         RenderableDiagnostic {
             severity: self.severity,
+            id: self.id.as_deref(),
             message: &self.message,
             snippets_by_input,
         }
@@ -304,7 +305,7 @@ impl<'a> ResolvedDiagnostic<'a> {
 #[derive(Debug)]
 struct ResolvedAnnotation<'a> {
     path: &'a str,
-    input: Input,
+    diagnostic_source: DiagnosticSource,
     range: TextRange,
     line_start: OneIndexed,
     line_end: OneIndexed,
@@ -318,8 +319,12 @@ impl<'a> ResolvedAnnotation<'a> {
     /// `path` is the path of the file that this annotation points to.
     ///
     /// `input` is the contents of the file that this annotation points to.
-    fn new(path: &'a str, input: &Input, ann: &'a Annotation) -> Option<ResolvedAnnotation<'a>> {
-        let source = input.as_source_code();
+    fn new(
+        path: &'a str,
+        diagnostic_source: &DiagnosticSource,
+        ann: &'a Annotation,
+    ) -> Option<ResolvedAnnotation<'a>> {
+        let source = diagnostic_source.as_source_code();
         let (range, line_start, line_end) = match (ann.span.range(), ann.message.is_some()) {
             // An annotation with no range AND no message is probably(?)
             // meaningless, but we should try to render it anyway.
@@ -345,7 +350,7 @@ impl<'a> ResolvedAnnotation<'a> {
         };
         Some(ResolvedAnnotation {
             path,
-            input: input.clone(),
+            diagnostic_source: diagnostic_source.clone(),
             range,
             line_start,
             line_end,
@@ -364,20 +369,6 @@ impl<'a> ResolvedAnnotation<'a> {
 /// renderable value. This is usually the lifetime of `Resolved`.
 #[derive(Debug)]
 struct Renderable<'r> {
-    // TODO: This is currently unused in the rendering logic below. I'm not
-    // 100% sure yet where I want to put it, but I like what `rustc` does:
-    //
-    //     error[E0599]: no method named `sub_builder` <..snip..>
-    //
-    // I believe in order to do this, we'll need to patch it in to
-    // `ruff_annotate_snippets` though. We leave it here for now with that plan
-    // in mind.
-    //
-    // (At time of writing, 2025-03-13, we currently render the diagnostic
-    // ID into the main message of the parent diagnostic. We don't use this
-    // specific field to do that though.)
-    #[allow(dead_code)]
-    id: &'r str,
     diagnostics: Vec<RenderableDiagnostic<'r>>,
 }
 
@@ -386,6 +377,12 @@ struct Renderable<'r> {
 struct RenderableDiagnostic<'r> {
     /// The severity of the diagnostic.
     severity: Severity,
+    /// The ID of the diagnostic. The ID can usually be used on the CLI or in a
+    /// config file to change the severity of a lint.
+    ///
+    /// An ID is always present for top-level diagnostics and always absent for
+    /// sub-diagnostics.
+    id: Option<&'r str>,
     /// The message emitted with the diagnostic, before any snippets are
     /// rendered.
     message: &'r str,
@@ -406,7 +403,11 @@ impl RenderableDiagnostic<'_> {
                 .iter()
                 .map(|snippet| snippet.to_annotate(path))
         });
-        level.title(self.message).snippets(snippets)
+        let mut message = level.title(self.message);
+        if let Some(id) = self.id {
+            message = message.id(id);
+        }
+        message.snippets(snippets)
     }
 }
 
@@ -510,8 +511,8 @@ impl<'r> RenderableSnippet<'r> {
             !anns.is_empty(),
             "creating a renderable snippet requires a non-zero number of annotations",
         );
-        let input = &anns[0].input;
-        let source = input.as_source_code();
+        let diagnostic_source = &anns[0].diagnostic_source;
+        let source = diagnostic_source.as_source_code();
         let has_primary = anns.iter().any(|ann| ann.is_primary);
 
         let line_start = context_before(
@@ -527,7 +528,7 @@ impl<'r> RenderableSnippet<'r> {
 
         let snippet_start = source.line_start(line_start);
         let snippet_end = source.line_end(line_end);
-        let snippet = input
+        let snippet = diagnostic_source
             .as_source_code()
             .slice(TextRange::new(snippet_start, snippet_end));
 
@@ -613,7 +614,7 @@ impl<'r> RenderableAnnotation<'r> {
     }
 }
 
-/// A type that facilitates the retrieval of source code from a `Span`.
+/// A trait that facilitates the retrieval of source code from a `Span`.
 ///
 /// At present, this is tightly coupled with a Salsa database. In the future,
 /// it is intended for this resolver to become an abstraction providing a
@@ -624,40 +625,28 @@ impl<'r> RenderableAnnotation<'r> {
 /// For example, at time of writing (2025-03-07), the plan is (roughly) for
 /// Ruff to grow its own interner of file paths so that a `Span` can store an
 /// interned ID instead of a (roughly) `Arc<Path>`. This interner is planned
-/// to be entirely separate from the Salsa interner used by Red Knot, and so,
+/// to be entirely separate from the Salsa interner used by ty, and so,
 /// callers will need to pass in a different "resolver" for turning `Span`s
 /// into actual file paths/contents. The infrastructure for this isn't fully in
 /// place, but this type serves to demarcate the intended abstraction boundary.
-pub(crate) struct FileResolver<'a> {
-    db: &'a dyn Db,
-}
-
-impl<'a> FileResolver<'a> {
-    /// Creates a new resolver from a Salsa database.
-    pub(crate) fn new(db: &'a dyn Db) -> FileResolver<'a> {
-        FileResolver { db }
-    }
-
+pub trait FileResolver {
     /// Returns the path associated with the file given.
-    fn path(&self, file: File) -> &'a str {
-        relativize_path(
-            self.db.system().current_directory(),
-            file.path(self.db).as_str(),
-        )
-    }
+    fn path(&self, file: File) -> &str;
 
     /// Returns the input contents associated with the file given.
-    fn input(&self, file: File) -> Input {
-        Input {
-            text: source_text(self.db, file),
-            line_index: line_index(self.db, file),
-        }
-    }
+    fn input(&self, file: File) -> Input;
 }
 
-impl std::fmt::Debug for FileResolver<'_> {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
-        write!(f, "<salsa based file resolver>")
+impl FileResolver for &dyn Db {
+    fn path(&self, file: File) -> &str {
+        relativize_path(self.system().current_directory(), file.path(*self).as_str())
+    }
+
+    fn input(&self, file: File) -> Input {
+        Input {
+            text: source_text(*self, file),
+            line_index: line_index(*self, file),
+        }
     }
 }
 
@@ -667,16 +656,9 @@ impl std::fmt::Debug for FileResolver<'_> {
 /// This contains the actual content of that input as well as a
 /// line index for efficiently querying its contents.
 #[derive(Clone, Debug)]
-struct Input {
-    text: SourceText,
-    line_index: LineIndex,
-}
-
-impl Input {
-    /// Returns this input as a `SourceCode` for convenient querying.
-    fn as_source_code(&self) -> SourceCode<'_, '_> {
-        SourceCode::new(self.text.as_str(), &self.line_index)
-    }
+pub struct Input {
+    pub(crate) text: SourceText,
+    pub(crate) line_index: LineIndex,
 }
 
 /// Returns the line number accounting for the given `len`
@@ -726,6 +708,7 @@ fn relativize_path<'p>(cwd: &SystemPath, path: &'p str) -> &'p str {
 #[cfg(test)]
 mod tests {
 
+    use crate::Upcast;
     use crate::diagnostic::{Annotation, DiagnosticId, Severity, Span};
     use crate::files::system_path_to_file;
     use crate::system::{DbWithWritableSystem, SystemPath};
@@ -803,7 +786,7 @@ watermelon
         insta::assert_snapshot!(
             env.render(&diag),
             @r"
-        error: lint:test-diagnostic: main diagnostic message
+        error[test-diagnostic]: main diagnostic message
          --> animals:5:1
           |
         3 | canary
@@ -827,7 +810,7 @@ watermelon
         insta::assert_snapshot!(
             env.render(&diag),
             @r"
-        warning: lint:test-diagnostic: main diagnostic message
+        warning[test-diagnostic]: main diagnostic message
          --> animals:5:1
           |
         3 | canary
@@ -847,7 +830,7 @@ watermelon
         insta::assert_snapshot!(
             env.render(&diag),
             @r"
-        info: lint:test-diagnostic: main diagnostic message
+        info[test-diagnostic]: main diagnostic message
          --> animals:5:1
           |
         3 | canary
@@ -874,7 +857,7 @@ watermelon
         insta::assert_snapshot!(
             env.render(&diag),
             @r"
-        error: lint:test-diagnostic: main diagnostic message
+        error[test-diagnostic]: main diagnostic message
          --> animals:1:1
           |
         1 | aardvark
@@ -893,7 +876,7 @@ watermelon
         insta::assert_snapshot!(
             env.render(&diag),
             @r"
-        error: lint:test-diagnostic: main diagnostic message
+        error[test-diagnostic]: main diagnostic message
          --> animals:1:1
           |
         1 | aardvark
@@ -914,7 +897,7 @@ watermelon
         insta::assert_snapshot!(
             env.render(&diag),
             @r"
-        error: lint:test-diagnostic: main diagnostic message
+        error[test-diagnostic]: main diagnostic message
          --> non-ascii:5:1
           |
         3 | ΔΔΔΔΔΔΔΔΔΔΔΔ
@@ -933,7 +916,7 @@ watermelon
         insta::assert_snapshot!(
             env.render(&diag),
             @r"
-        error: lint:test-diagnostic: main diagnostic message
+        error[test-diagnostic]: main diagnostic message
          --> non-ascii:2:2
           |
         1 | ☃☃☃☃☃☃☃☃☃☃☃☃
@@ -957,7 +940,7 @@ watermelon
         insta::assert_snapshot!(
             env.render(&diag),
             @r"
-        error: lint:test-diagnostic: main diagnostic message
+        error[test-diagnostic]: main diagnostic message
          --> animals:5:1
           |
         4 | dog
@@ -974,7 +957,7 @@ watermelon
         insta::assert_snapshot!(
             env.render(&diag),
             @r"
-        error: lint:test-diagnostic: main diagnostic message
+        error[test-diagnostic]: main diagnostic message
          --> animals:5:1
           |
         5 | elephant
@@ -989,7 +972,7 @@ watermelon
         insta::assert_snapshot!(
             env.render(&diag),
             @r"
-        error: lint:test-diagnostic: main diagnostic message
+        error[test-diagnostic]: main diagnostic message
          --> animals:1:1
           |
         1 | aardvark
@@ -1006,7 +989,7 @@ watermelon
         insta::assert_snapshot!(
             env.render(&diag),
             @r"
-        error: lint:test-diagnostic: main diagnostic message
+        error[test-diagnostic]: main diagnostic message
           --> animals:11:1
            |
          9 | inchworm
@@ -1023,7 +1006,7 @@ watermelon
         insta::assert_snapshot!(
             env.render(&diag),
             @r"
-        error: lint:test-diagnostic: main diagnostic message
+        error[test-diagnostic]: main diagnostic message
           --> animals:5:1
            |
          1 | aardvark
@@ -1056,7 +1039,7 @@ watermelon
         insta::assert_snapshot!(
             env.render(&diag),
             @r"
-        error: lint:test-diagnostic: main diagnostic message
+        error[test-diagnostic]: main diagnostic message
           --> animals:1:1
            |
          1 | aardvark
@@ -1100,7 +1083,7 @@ watermelon
         insta::assert_snapshot!(
             env.render(&diag),
             @r"
-        error: lint:test-diagnostic: main diagnostic message
+        error[test-diagnostic]: main diagnostic message
          --> animals:1:1
           |
         1 | aardvark
@@ -1125,7 +1108,7 @@ watermelon
         insta::assert_snapshot!(
             env.render(&diag),
             @r"
-        error: lint:test-diagnostic: main diagnostic message
+        error[test-diagnostic]: main diagnostic message
          --> animals:1:1
           |
         1 | aardvark
@@ -1153,7 +1136,7 @@ watermelon
         insta::assert_snapshot!(
             env.render(&diag),
             @r"
-        error: lint:test-diagnostic: main diagnostic message
+        error[test-diagnostic]: main diagnostic message
          --> animals:1:1
           |
         1 | aardvark
@@ -1181,7 +1164,7 @@ watermelon
         insta::assert_snapshot!(
             env.render(&diag),
             @r"
-        error: lint:test-diagnostic: main diagnostic message
+        error[test-diagnostic]: main diagnostic message
          --> animals:1:1
           |
         1 | aardvark
@@ -1206,7 +1189,7 @@ watermelon
         insta::assert_snapshot!(
             env.render(&diag),
             @r"
-        error: lint:test-diagnostic: main diagnostic message
+        error[test-diagnostic]: main diagnostic message
           --> animals:1:1
            |
          1 | aardvark
@@ -1237,7 +1220,7 @@ watermelon
         insta::assert_snapshot!(
             env.render(&diag),
             @r"
-        error: lint:test-diagnostic: main diagnostic message
+        error[test-diagnostic]: main diagnostic message
           --> animals:1:1
            |
          1 | aardvark
@@ -1275,7 +1258,7 @@ watermelon
         insta::assert_snapshot!(
             env.render(&diag),
             @r"
-        error: lint:test-diagnostic: main diagnostic message
+        error[test-diagnostic]: main diagnostic message
          --> spacey-animals:8:1
           |
         7 | dog
@@ -1292,7 +1275,7 @@ watermelon
         insta::assert_snapshot!(
             env.render(&diag),
             @r"
-        error: lint:test-diagnostic: main diagnostic message
+        error[test-diagnostic]: main diagnostic message
           --> spacey-animals:12:1
            |
         11 | gorilla
@@ -1310,7 +1293,7 @@ watermelon
         insta::assert_snapshot!(
             env.render(&diag),
             @r"
-        error: lint:test-diagnostic: main diagnostic message
+        error[test-diagnostic]: main diagnostic message
           --> spacey-animals:13:1
            |
         11 | gorilla
@@ -1350,7 +1333,7 @@ watermelon
         insta::assert_snapshot!(
             env.render(&diag),
             @r"
-        error: lint:test-diagnostic: main diagnostic message
+        error[test-diagnostic]: main diagnostic message
          --> spacey-animals:3:1
           |
         3 | beetle
@@ -1379,7 +1362,7 @@ watermelon
         insta::assert_snapshot!(
             env.render(&diag),
             @r"
-        error: lint:test-diagnostic: main diagnostic message
+        error[test-diagnostic]: main diagnostic message
          --> animals:3:1
           |
         1 | aardvark
@@ -1416,7 +1399,7 @@ watermelon
         insta::assert_snapshot!(
             env.render(&diag),
             @r"
-        error: lint:test-diagnostic: main diagnostic message
+        error[test-diagnostic]: main diagnostic message
          --> animals:3:1
           |
         1 | aardvark
@@ -1453,7 +1436,7 @@ watermelon
         insta::assert_snapshot!(
             env.render(&diag),
             @r"
-        error: lint:test-diagnostic: main diagnostic message
+        error[test-diagnostic]: main diagnostic message
          --> animals:3:1
           |
         1 | aardvark
@@ -1481,7 +1464,7 @@ watermelon
         insta::assert_snapshot!(
             env.render(&diag),
             @r"
-        error: lint:test-diagnostic: main diagnostic message
+        error[test-diagnostic]: main diagnostic message
          --> animals:3:1
           |
         1 | aardvark
@@ -1517,7 +1500,7 @@ watermelon
         insta::assert_snapshot!(
             env.render(&diag),
             @r"
-        error: lint:test-diagnostic: main diagnostic message
+        error[test-diagnostic]: main diagnostic message
          --> animals:3:1
           |
         1 | aardvark
@@ -1556,7 +1539,7 @@ watermelon
         insta::assert_snapshot!(
             env.render(&diag),
             @r"
-        error: lint:test-diagnostic: main diagnostic message
+        error[test-diagnostic]: main diagnostic message
          --> animals:3:1
           |
         1 | aardvark
@@ -1604,7 +1587,7 @@ watermelon
         insta::assert_snapshot!(
             env.render(&diag),
             @r"
-        error: lint:test-diagnostic: main diagnostic message
+        error[test-diagnostic]: main diagnostic message
          --> animals:3:1
           |
         1 | aardvark
@@ -1640,7 +1623,7 @@ watermelon
         insta::assert_snapshot!(
             env.render(&diag),
             @r"
-        error: lint:test-diagnostic: main diagnostic message
+        error[test-diagnostic]: main diagnostic message
          --> animals:5:1
           |
         3 |   canary
@@ -1663,7 +1646,7 @@ watermelon
         insta::assert_snapshot!(
             env.render(&diag),
             @r"
-        error: lint:test-diagnostic: main diagnostic message
+        error[test-diagnostic]: main diagnostic message
          --> animals:5:1
           |
         3 |   canary
@@ -1683,7 +1666,7 @@ watermelon
         insta::assert_snapshot!(
             env.render(&diag),
             @r"
-        error: lint:test-diagnostic: main diagnostic message
+        error[test-diagnostic]: main diagnostic message
          --> animals:5:1
           |
         3 |   canary
@@ -1703,7 +1686,7 @@ watermelon
         insta::assert_snapshot!(
             env.render(&diag),
             @r"
-        error: lint:test-diagnostic: main diagnostic message
+        error[test-diagnostic]: main diagnostic message
           --> animals:5:4
            |
          3 |   canary
@@ -1725,7 +1708,7 @@ watermelon
         insta::assert_snapshot!(
             env.render(&diag),
             @r"
-        error: lint:test-diagnostic: main diagnostic message
+        error[test-diagnostic]: main diagnostic message
           --> animals:5:4
            |
          3 |   canary
@@ -1757,7 +1740,7 @@ watermelon
         insta::assert_snapshot!(
             env.render(&diag),
             @r"
-        error: lint:test-diagnostic: main diagnostic message
+        error[test-diagnostic]: main diagnostic message
          --> animals:4:1
           |
         2 |    beetle
@@ -1786,7 +1769,7 @@ watermelon
         insta::assert_snapshot!(
             env.render(&diag),
             @r"
-        error: lint:test-diagnostic: main diagnostic message
+        error[test-diagnostic]: main diagnostic message
          --> animals:4:1
           |
         2 |    beetle
@@ -1817,7 +1800,7 @@ watermelon
         insta::assert_snapshot!(
             env.render(&diag),
             @r"
-        error: lint:test-diagnostic: main diagnostic message
+        error[test-diagnostic]: main diagnostic message
          --> animals:5:1
           |
         3 |    canary
@@ -1852,7 +1835,7 @@ watermelon
         insta::assert_snapshot!(
             env.render(&diag),
             @r"
-        error: lint:test-diagnostic: main diagnostic message
+        error[test-diagnostic]: main diagnostic message
          --> animals:5:1
           |
         3 |    canary
@@ -1880,7 +1863,7 @@ watermelon
         insta::assert_snapshot!(
             env.render(&diag),
             @r"
-        error: lint:test-diagnostic: main diagnostic message
+        error[test-diagnostic]: main diagnostic message
          --> animals:5:1
           |
         3 |    canary
@@ -1912,7 +1895,7 @@ watermelon
         insta::assert_snapshot!(
             env.render(&diag),
             @r"
-        error: lint:test-diagnostic: main diagnostic message
+        error[test-diagnostic]: main diagnostic message
          --> animals:5:3
           |
         3 | canary
@@ -1934,7 +1917,7 @@ watermelon
         insta::assert_snapshot!(
             env.render(&diag),
             @r"
-        error: lint:test-diagnostic: main diagnostic message
+        error[test-diagnostic]: main diagnostic message
          --> animals:5:3
           |
         3 | canary
@@ -1967,7 +1950,7 @@ watermelon
         insta::assert_snapshot!(
             env.render(&diag),
             @r"
-        error: lint:test-diagnostic: main diagnostic message
+        error[test-diagnostic]: main diagnostic message
           --> animals:8:1
            |
          6 | finch
@@ -2007,7 +1990,7 @@ watermelon
         insta::assert_snapshot!(
             env.render(&diag),
             @r"
-        error: lint:test-diagnostic: main diagnostic message
+        error[test-diagnostic]: main diagnostic message
          --> animals:5:1
           |
         5 | elephant
@@ -2051,7 +2034,7 @@ watermelon
         insta::assert_snapshot!(
             env.render(&diag),
             @r"
-        error: lint:test-diagnostic: main diagnostic message
+        error[test-diagnostic]: main diagnostic message
          --> fruits:1:1
           |
         1 | apple
@@ -2086,7 +2069,7 @@ watermelon
         insta::assert_snapshot!(
             env.render(&diag),
             @r"
-        error: lint:test-diagnostic: main diagnostic message
+        error[test-diagnostic]: main diagnostic message
           --> animals:11:1
            |
         11 | kangaroo
@@ -2174,8 +2157,9 @@ watermelon
         fn span(&self, path: &str, line_offset_start: &str, line_offset_end: &str) -> Span {
             let span = self.path(path);
 
-            let text = source_text(&self.db, span.file());
-            let line_index = line_index(&self.db, span.file());
+            let file = span.expect_ty_file();
+            let text = source_text(&self.db, file);
+            let line_index = line_index(&self.db, file);
             let source = SourceCode::new(text.as_str(), &line_index);
 
             let (line_start, offset_start) = parse_line_offset(line_offset_start);
@@ -2237,7 +2221,7 @@ watermelon
         ///
         /// (This will set the "printed" flag on `Diagnostic`.)
         fn render(&self, diag: &Diagnostic) -> String {
-            diag.display(&self.db, &self.config).to_string()
+            diag.display(&self.db.upcast(), &self.config).to_string()
         }
     }
 

crates/ruff_db/src/files.rs

@@ -11,12 +11,13 @@ use ruff_text_size::{Ranged, TextRange};
 use salsa::plumbing::AsId;
 use salsa::{Durability, Setter};
 
+use crate::diagnostic::{Span, UnifiedFile};
 use crate::file_revision::FileRevision;
 use crate::files::file_root::FileRoots;
 use crate::files::private::FileStatus;
 use crate::system::{SystemPath, SystemPathBuf, SystemVirtualPath, SystemVirtualPathBuf};
 use crate::vendored::{VendoredPath, VendoredPathBuf};
-use crate::{vendored, Db, FxDashMap};
+use crate::{Db, FxDashMap, vendored};
 
 mod file_root;
 mod path;
@@ -274,10 +275,15 @@ impl fmt::Debug for Files {
 impl std::panic::RefUnwindSafe for Files {}
 
 /// A file that's either stored on the host system's file system or in the vendored file system.
+///
+/// # Ordering
+/// Ordering is based on the file's salsa-assigned id and not on its values.
+/// The id may change between runs.
 #[salsa::input]
+#[derive(PartialOrd, Ord)]
 pub struct File {
     /// The path of the file (immutable).
-    #[return_ref]
+    #[returns(ref)]
     pub path: FilePath,
 
     /// The unix permissions of the file. Only supported on unix systems. Always `None` on Windows
@@ -549,10 +555,33 @@ impl Ranged for FileRange {
     }
 }
 
+impl TryFrom<&Span> for FileRange {
+    type Error = ();
+
+    fn try_from(value: &Span) -> Result<Self, Self::Error> {
+        let UnifiedFile::Ty(file) = value.file() else {
+            return Err(());
+        };
+
+        Ok(Self {
+            file: *file,
+            range: value.range().ok_or(())?,
+        })
+    }
+}
+
+impl TryFrom<Span> for FileRange {
+    type Error = ();
+
+    fn try_from(value: Span) -> Result<Self, Self::Error> {
+        Self::try_from(&value)
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use crate::file_revision::FileRevision;
-    use crate::files::{system_path_to_file, vendored_path_to_file, FileError};
+    use crate::files::{FileError, system_path_to_file, vendored_path_to_file};
     use crate::system::DbWithWritableSystem as _;
     use crate::tests::TestDb;
     use crate::vendored::VendoredFileSystemBuilder;

crates/ruff_db/src/files/file_root.rs

@@ -3,9 +3,9 @@ use std::fmt::Formatter;
 use path_slash::PathExt;
 use salsa::Durability;
 
+use crate::Db;
 use crate::file_revision::FileRevision;
 use crate::system::{SystemPath, SystemPathBuf};
-use crate::Db;
 
 /// A root path for files tracked by the database.
 ///
@@ -19,8 +19,8 @@ use crate::Db;
 #[salsa::input(debug)]
 pub struct FileRoot {
     /// The path of a root is guaranteed to never change.
-    #[return_ref]
-    path_buf: SystemPathBuf,
+    #[returns(deref)]
+    pub path: SystemPathBuf,
 
     /// The kind of the root at the time of its creation.
     kind_at_time_of_creation: FileRootKind,
@@ -32,10 +32,6 @@ pub struct FileRoot {
 }
 
 impl FileRoot {
-    pub fn path(self, db: &dyn Db) -> &SystemPath {
-        self.path_buf(db)
-    }
-
     pub fn durability(self, db: &dyn Db) -> salsa::Durability {
         self.kind_at_time_of_creation(db).durability()
     }

crates/ruff_db/src/files/path.rs

@@ -1,7 +1,7 @@
-use crate::files::{system_path_to_file, vendored_path_to_file, File};
+use crate::Db;
+use crate::files::{File, system_path_to_file, vendored_path_to_file};
 use crate::system::{SystemPath, SystemPathBuf, SystemVirtualPath, SystemVirtualPathBuf};
 use crate::vendored::{VendoredPath, VendoredPathBuf};
-use crate::Db;
 use std::fmt::{Display, Formatter};
 
 /// Path to a file.

crates/ruff_db/src/lib.rs

@@ -1,11 +1,10 @@
-use std::hash::BuildHasherDefault;
-
-use ruff_python_ast::PythonVersion;
-use rustc_hash::FxHasher;
-
 use crate::files::Files;
 use crate::system::System;
 use crate::vendored::VendoredFileSystem;
+use ruff_python_ast::PythonVersion;
+use rustc_hash::FxHasher;
+use std::hash::BuildHasherDefault;
+use std::num::NonZeroUsize;
 
 pub mod diagnostic;
 pub mod display;
@@ -37,15 +36,40 @@ pub trait Upcast<T: ?Sized> {
     fn upcast_mut(&mut self) -> &mut T;
 }
 
+/// Returns the maximum number of tasks that ty is allowed
+/// to process in parallel.
+///
+/// Returns [`std::thread::available_parallelism`], unless the environment
+/// variable `TY_MAX_PARALLELISM` or `RAYON_NUM_THREADS` is set. `TY_MAX_PARALLELISM` takes
+/// precedence over `RAYON_NUM_THREADS`.
+///
+/// Falls back to `1` if `available_parallelism` is not available.
+///
+/// Setting `TY_MAX_PARALLELISM` to `2` only restricts the number of threads that ty spawns
+/// to process work in parallel. For example, to index a directory or checking the files of a project.
+/// ty can still spawn more threads for other tasks, e.g. to wait for a Ctrl+C signal or
+/// watching the files for changes.
+pub fn max_parallelism() -> NonZeroUsize {
+    std::env::var("TY_MAX_PARALLELISM")
+        .or_else(|_| std::env::var("RAYON_NUM_THREADS"))
+        .ok()
+        .and_then(|s| s.parse().ok())
+        .unwrap_or_else(|| {
+            std::thread::available_parallelism().unwrap_or_else(|_| NonZeroUsize::new(1).unwrap())
+        })
+}
+
 #[cfg(test)]
 mod tests {
-    use std::sync::Arc;
+    use std::sync::{Arc, Mutex};
 
     use crate::files::Files;
     use crate::system::TestSystem;
     use crate::system::{DbWithTestSystem, System};
     use crate::vendored::VendoredFileSystem;
-    use crate::Db;
+    use crate::{Db, Upcast};
+
+    type Events = Arc<Mutex<Vec<salsa::Event>>>;
 
     /// Database that can be used for testing.
     ///
@@ -57,36 +81,37 @@ mod tests {
         files: Files,
         system: TestSystem,
         vendored: VendoredFileSystem,
-        events: Arc<std::sync::Mutex<Vec<salsa::Event>>>,
+        events: Events,
     }
 
     impl TestDb {
         pub(crate) fn new() -> Self {
+            let events = Events::default();
             Self {
-                storage: salsa::Storage::default(),
+                storage: salsa::Storage::new(Some(Box::new({
+                    let events = events.clone();
+                    move |event| {
+                        tracing::trace!("event: {:?}", event);
+                        let mut events = events.lock().unwrap();
+                        events.push(event);
+                    }
+                }))),
                 system: TestSystem::default(),
                 vendored: VendoredFileSystem::default(),
-                events: std::sync::Arc::default(),
+                events,
                 files: Files::default(),
             }
         }
 
         /// Empties the internal store of salsa events that have been emitted,
         /// and returns them as a `Vec` (equivalent to [`std::mem::take`]).
-        ///
-        /// ## Panics
-        /// If there are pending database snapshots.
         pub(crate) fn take_salsa_events(&mut self) -> Vec<salsa::Event> {
-            let inner = Arc::get_mut(&mut self.events)
-                .expect("expected no pending salsa database snapshots.");
+            let mut events = self.events.lock().unwrap();
 
-            std::mem::take(inner.get_mut().unwrap())
+            std::mem::take(&mut *events)
         }
 
         /// Clears the emitted salsa events.
-        ///
-        /// ## Panics
-        /// If there are pending database snapshots.
         pub(crate) fn clear_salsa_events(&mut self) {
             self.take_salsa_events();
         }
@@ -111,7 +136,16 @@ mod tests {
         }
 
         fn python_version(&self) -> ruff_python_ast::PythonVersion {
-            ruff_python_ast::PythonVersion::latest()
+            ruff_python_ast::PythonVersion::latest_ty()
+        }
+    }
+
+    impl Upcast<dyn Db> for TestDb {
+        fn upcast(&self) -> &(dyn Db + 'static) {
+            self
+        }
+        fn upcast_mut(&mut self) -> &mut (dyn Db + 'static) {
+            self
         }
     }
 
@@ -126,12 +160,5 @@ mod tests {
     }
 
     #[salsa::db]
-    impl salsa::Database for TestDb {
-        fn salsa_event(&self, event: &dyn Fn() -> salsa::Event) {
-            let event = event();
-            tracing::trace!("event: {:?}", event);
-            let mut events = self.events.lock().unwrap();
-            events.push(event);
-        }
-    }
+    impl salsa::Database for TestDb {}
 }

crates/ruff_db/src/parsed.rs

@@ -3,11 +3,11 @@ use std::ops::Deref;
 use std::sync::Arc;
 
 use ruff_python_ast::ModModule;
-use ruff_python_parser::{parse_unchecked, ParseOptions, Parsed};
+use ruff_python_parser::{ParseOptions, Parsed, parse_unchecked};
 
+use crate::Db;
 use crate::files::File;
 use crate::source::source_text;
-use crate::Db;
 
 /// Returns the parsed AST of `file`, including its token stream.
 ///
@@ -20,7 +20,7 @@ use crate::Db;
 /// reflected in the changed AST offsets.
 /// The other reason is that Ruff's AST doesn't implement `Eq` which Sala requires
 /// for determining if a query result is unchanged.
-#[salsa::tracked(return_ref, no_eq)]
+#[salsa::tracked(returns(ref), no_eq)]
 pub fn parsed_module(db: &dyn Db, file: File) -> ParsedModule {
     let _span = tracing::trace_span!("parsed_module", ?file).entered();
 
@@ -79,6 +79,7 @@ impl Eq for ParsedModule {}
 
 #[cfg(test)]
 mod tests {
+    use crate::Db;
     use crate::files::{system_path_to_file, vendored_path_to_file};
     use crate::parsed::parsed_module;
     use crate::system::{
@@ -86,7 +87,6 @@ mod tests {
     };
     use crate::tests::TestDb;
     use crate::vendored::{VendoredFileSystemBuilder, VendoredPath};
-    use crate::Db;
     use zip::CompressionMethod;
 
     #[test]

crates/ruff_db/src/source.rs

@@ -7,8 +7,8 @@ use ruff_notebook::Notebook;
 use ruff_python_ast::PySourceType;
 use ruff_source_file::LineIndex;
 
-use crate::files::{File, FilePath};
 use crate::Db;
+use crate::files::{File, FilePath};
 
 /// Reads the source text of a python text file (must be valid UTF8) or notebook.
 #[salsa::tracked]
@@ -133,7 +133,7 @@ struct SourceTextInner {
 #[derive(Eq, PartialEq)]
 enum SourceTextKind {
     Text(String),
-    Notebook(Notebook),
+    Notebook(Box<Notebook>),
 }
 
 impl From<String> for SourceTextKind {
@@ -144,7 +144,7 @@ impl From<String> for SourceTextKind {
 
 impl From<Notebook> for SourceTextKind {
     fn from(notebook: Notebook) -> Self {
-        SourceTextKind::Notebook(notebook)
+        SourceTextKind::Notebook(Box::new(notebook))
     }
 }
 
@@ -216,9 +216,11 @@ mod tests {
 
         let events = db.take_salsa_events();
 
-        assert!(!events
-            .iter()
-            .any(|event| matches!(event.kind, EventKind::WillExecute { .. })));
+        assert!(
+            !events
+                .iter()
+                .any(|event| matches!(event.kind, EventKind::WillExecute { .. }))
+        );
 
         Ok(())
     }

crates/ruff_db/src/system.rs

@@ -19,8 +19,8 @@ use walk_directory::WalkDirectoryBuilder;
 use crate::file_revision::FileRevision;
 
 pub use self::path::{
-    deduplicate_nested_paths, DeduplicatedNestedPathsIter, SystemPath, SystemPathBuf,
-    SystemVirtualPath, SystemVirtualPathBuf,
+    DeduplicatedNestedPathsIter, SystemPath, SystemPathBuf, SystemVirtualPath,
+    SystemVirtualPathBuf, deduplicate_nested_paths,
 };
 
 mod memory_fs;
@@ -167,7 +167,7 @@ pub trait System: Debug {
         &self,
         pattern: &str,
     ) -> std::result::Result<
-        Box<dyn Iterator<Item = std::result::Result<SystemPathBuf, GlobError>>>,
+        Box<dyn Iterator<Item = std::result::Result<SystemPathBuf, GlobError>> + '_>,
         PatternError,
     >;
 

crates/ruff_db/src/system/memory_fs.rs

@@ -7,8 +7,8 @@ use filetime::FileTime;
 use rustc_hash::FxHashMap;
 
 use crate::system::{
-    file_time_now, walk_directory, DirectoryEntry, FileType, GlobError, GlobErrorKind, Metadata,
-    Result, SystemPath, SystemPathBuf, SystemVirtualPath, SystemVirtualPathBuf,
+    DirectoryEntry, FileType, GlobError, GlobErrorKind, Metadata, Result, SystemPath,
+    SystemPathBuf, SystemVirtualPath, SystemVirtualPathBuf, file_time_now, walk_directory,
 };
 
 use super::walk_directory::{
@@ -236,7 +236,7 @@ impl MemoryFileSystem {
         &self,
         pattern: &str,
     ) -> std::result::Result<
-        impl Iterator<Item = std::result::Result<SystemPathBuf, GlobError>>,
+        impl Iterator<Item = std::result::Result<SystemPathBuf, GlobError>> + '_,
         glob::PatternError,
     > {
         // Very naive implementation that iterates over all files and collects all that match the given pattern.
@@ -463,17 +463,17 @@ fn not_found() -> std::io::Error {
 fn is_a_directory() -> std::io::Error {
     // Note: Rust returns `ErrorKind::IsADirectory` for this error but this is a nightly only variant :(.
     //   So we have to use other for now.
-    std::io::Error::new(std::io::ErrorKind::Other, "Is a directory")
+    std::io::Error::other("Is a directory")
 }
 
 fn not_a_directory() -> std::io::Error {
     // Note: Rust returns `ErrorKind::NotADirectory` for this error but this is a nightly only variant :(.
     //   So we have to use `Other` for now.
-    std::io::Error::new(std::io::ErrorKind::Other, "Not a directory")
+    std::io::Error::other("Not a directory")
 }
 
 fn directory_not_empty() -> std::io::Error {
-    std::io::Error::new(std::io::ErrorKind::Other, "directory not empty")
+    std::io::Error::other("directory not empty")
 }
 
 fn create_dir_all(
@@ -701,8 +701,8 @@ mod tests {
 
     use std::time::Duration;
 
-    use crate::system::walk_directory::tests::DirectoryEntryToString;
     use crate::system::walk_directory::WalkState;
+    use crate::system::walk_directory::tests::DirectoryEntryToString;
     use crate::system::{
         DirectoryEntry, FileType, MemoryFileSystem, Result, SystemPath, SystemPathBuf,
         SystemVirtualPath,

crates/ruff_db/src/system/os.rs

@@ -1,19 +1,19 @@
-use filetime::FileTime;
-use ruff_notebook::{Notebook, NotebookError};
-use rustc_hash::FxHashSet;
-use std::panic::RefUnwindSafe;
-use std::sync::Arc;
-use std::{any::Any, path::PathBuf};
-
-use crate::system::{
-    CaseSensitivity, DirectoryEntry, FileType, GlobError, GlobErrorKind, Metadata, Result, System,
-    SystemPath, SystemPathBuf, SystemVirtualPath, WritableSystem,
-};
-
 use super::walk_directory::{
     self, DirectoryWalker, WalkDirectoryBuilder, WalkDirectoryConfiguration,
     WalkDirectoryVisitorBuilder, WalkState,
 };
+use crate::max_parallelism;
+use crate::system::{
+    CaseSensitivity, DirectoryEntry, FileType, GlobError, GlobErrorKind, Metadata, Result, System,
+    SystemPath, SystemPathBuf, SystemVirtualPath, WritableSystem,
+};
+use filetime::FileTime;
+use ruff_notebook::{Notebook, NotebookError};
+use rustc_hash::FxHashSet;
+use std::num::NonZeroUsize;
+use std::panic::RefUnwindSafe;
+use std::sync::Arc;
+use std::{any::Any, path::PathBuf};
 
 /// A system implementation that uses the OS file system.
 #[derive(Debug, Clone)]
@@ -50,7 +50,6 @@ impl OsSystem {
 
         Self {
             // Spreading `..Default` because it isn't possible to feature gate the initializer of a single field.
-            #[allow(clippy::needless_update)]
             inner: Arc::new(OsSystemInner {
                 cwd: cwd.to_path_buf(),
                 case_sensitivity,
@@ -257,7 +256,9 @@ impl OsSystem {
         let Ok(canonicalized) = SystemPathBuf::from_path_buf(canonicalized) else {
             // The original path is valid UTF8 but the canonicalized path isn't. This definitely suggests
             // that a symlink is involved. Fall back to the slow path.
-            tracing::debug!("Falling back to the slow case-sensitive path existence check because the canonicalized path of `{simplified}` is not valid UTF-8");
+            tracing::debug!(
+                "Falling back to the slow case-sensitive path existence check because the canonicalized path of `{simplified}` is not valid UTF-8"
+            );
             return None;
         };
 
@@ -267,7 +268,9 @@ impl OsSystem {
         // `path` pointed to a symlink (or some other none reversible path normalization happened).
         // In this case, fall back to the slow path.
         if simplified_canonicalized.as_str().to_lowercase() != simplified.as_str().to_lowercase() {
-            tracing::debug!("Falling back to the slow case-sensitive path existence check for `{simplified}` because the canonicalized path `{simplified_canonicalized}` differs not only by casing");
+            tracing::debug!(
+                "Falling back to the slow case-sensitive path existence check for `{simplified}` because the canonicalized path `{simplified_canonicalized}` differs not only by casing"
+            );
             return None;
         }
 
@@ -427,11 +430,7 @@ impl DirectoryWalker for OsDirectoryWalker {
             builder.add(additional_path.as_std_path());
         }
 
-        builder.threads(
-            std::thread::available_parallelism()
-                .map_or(1, std::num::NonZeroUsize::get)
-                .min(12),
-        );
+        builder.threads(max_parallelism().min(NonZeroUsize::new(12).unwrap()).get());
 
         builder.build_parallel().run(|| {
             let mut visitor = visitor_builder.build();
@@ -667,8 +666,8 @@ fn detect_case_sensitivity(path: &SystemPath) -> CaseSensitivity {
 mod tests {
     use tempfile::TempDir;
 
-    use crate::system::walk_directory::tests::DirectoryEntryToString;
     use crate::system::DirectoryEntry;
+    use crate::system::walk_directory::tests::DirectoryEntryToString;
 
     use super::*;
 

crates/ruff_db/src/system/test.rs

@@ -3,15 +3,15 @@ use ruff_notebook::{Notebook, NotebookError};
 use std::panic::RefUnwindSafe;
 use std::sync::{Arc, Mutex};
 
+use crate::Db;
 use crate::files::File;
 use crate::system::{
     CaseSensitivity, DirectoryEntry, GlobError, MemoryFileSystem, Metadata, Result, System,
     SystemPath, SystemPathBuf, SystemVirtualPath,
 };
-use crate::Db;
 
-use super::walk_directory::WalkDirectoryBuilder;
 use super::WritableSystem;
+use super::walk_directory::WalkDirectoryBuilder;
 
 /// System implementation intended for testing.
 ///
@@ -117,7 +117,7 @@ impl System for TestSystem {
         &self,
         pattern: &str,
     ) -> std::result::Result<
-        Box<dyn Iterator<Item = std::result::Result<SystemPathBuf, GlobError>>>,
+        Box<dyn Iterator<Item = std::result::Result<SystemPathBuf, GlobError>> + '_>,
         PatternError,
     > {
         self.system().glob(pattern)
@@ -343,7 +343,7 @@ impl System for InMemorySystem {
         &self,
         pattern: &str,
     ) -> std::result::Result<
-        Box<dyn Iterator<Item = std::result::Result<SystemPathBuf, GlobError>>>,
+        Box<dyn Iterator<Item = std::result::Result<SystemPathBuf, GlobError>> + '_>,
         PatternError,
     > {
         let iterator = self.memory_fs.glob(pattern)?;

crates/ruff_db/src/system/walk_directory.rs

@@ -35,7 +35,7 @@ impl WalkDirectoryBuilder {
     /// Each additional path is traversed recursively.
     /// This should be preferred over building multiple
     /// walkers since it enables reusing resources.
-    #[allow(clippy::should_implement_trait)]
+    #[expect(clippy::should_implement_trait)]
     pub fn add(mut self, path: impl AsRef<SystemPath>) -> Self {
         self.paths.push(path.as_ref().to_path_buf());
         self