[ty] only issue redundant-cast on fully static types

## Summary

Fixes #18011

.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/mypy-primer-ty.toml

@@ -0,0 +1,7 @@
+#: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"

.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"
@@ -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"

.github/workflows/build-docker.yml

@@ -40,7 +40,7 @@ jobs:
 
       - uses: docker/setup-buildx-action@b5ca514318bd6ebac0fb2aedd5d36ec1b5c232a2 # v3
 
-      - uses: docker/login-action@74a5d142397b4f367a81961eba4e8cd7edddf772 # v3
+      - uses: docker/login-action@74a5d142397b4f367a81961eba4e8cd7edddf772 # v3.4.0
         with:
           registry: ghcr.io
           username: ${{ github.repository_owner }}
@@ -79,7 +79,7 @@ jobs:
       # Adapted from https://docs.docker.com/build/ci/github-actions/multi-platform/
       - name: Build and push by digest
         id: build
-        uses: docker/build-push-action@471d1dc4e07e5cdedd4c2171150001c434f0b7a4 # v6
+        uses: docker/build-push-action@14487ce63c7a62a4a324b0bfb37086795e31c6c1 # v6.16.0
         with:
           context: .
           platforms: ${{ matrix.platform }}
@@ -113,7 +113,7 @@ jobs:
     if: ${{ inputs.plan != '' && !fromJson(inputs.plan).announcement_tag_is_implicit }}
     steps:
       - name: Download digests
-        uses: actions/download-artifact@95815c38cf2ff2164869cbab79da8d1f422bc89e # v4.2.1
+        uses: actions/download-artifact@d3f86a106a0bac45b974a628896c90dbdf5c8093 # v4.3.0
         with:
           path: /tmp/digests
           pattern: digests-*
@@ -131,7 +131,7 @@ jobs:
             type=pep440,pattern={{ version }},value=${{ 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 }}
@@ -169,7 +169,7 @@ jobs:
     steps:
       - uses: docker/setup-buildx-action@b5ca514318bd6ebac0fb2aedd5d36ec1b5c232a2 # v3
 
-      - uses: docker/login-action@74a5d142397b4f367a81961eba4e8cd7edddf772 # v3
+      - uses: docker/login-action@74a5d142397b4f367a81961eba4e8cd7edddf772 # v3.4.0
         with:
           registry: ghcr.io
           username: ${{ github.repository_owner }}
@@ -231,7 +231,7 @@ jobs:
             ${{ env.TAG_PATTERNS }}
 
       - name: Build and push
-        uses: docker/build-push-action@471d1dc4e07e5cdedd4c2171150001c434f0b7a4 # v6
+        uses: docker/build-push-action@14487ce63c7a62a4a324b0bfb37086795e31c6c1 # v6.16.0
         with:
           context: .
           platforms: linux/amd64,linux/arm64
@@ -256,7 +256,7 @@ jobs:
     if: ${{ inputs.plan != '' && !fromJson(inputs.plan).announcement_tag_is_implicit }}
     steps:
       - name: Download digests
-        uses: actions/download-artifact@95815c38cf2ff2164869cbab79da8d1f422bc89e # v4.2.1
+        uses: actions/download-artifact@d3f86a106a0bac45b974a628896c90dbdf5c8093 # v4.3.0
         with:
           path: /tmp/digests
           pattern: digests-*
@@ -276,7 +276,7 @@ jobs:
             type=pep440,pattern={{ version }},value=${{ 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@09dc018eee06ae1c9e0409786563f534210ceb83 # v2
+        uses: taiki-e/install-action@83254c543806f3224380bf1001d6fac8feaf2d0b # v2
         with:
           tool: cargo-nextest
       - name: "Install cargo insta"
-        uses: taiki-e/install-action@09dc018eee06ae1c9e0409786563f534210ceb83 # v2
+        uses: taiki-e/install-action@83254c543806f3224380bf1001d6fac8feaf2d0b # v2
         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"
@@ -276,6 +276,10 @@ jobs:
         with:
           name: ruff
           path: target/debug/ruff
+      - uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02 # v4.6.2
+        with:
+          name: ty
+          path: target/debug/ty
 
   cargo-test-linux-release:
     name: "cargo test (linux, release)"
@@ -293,11 +297,11 @@ jobs:
       - name: "Install mold"
         uses: rui314/setup-mold@e16410e7f8d9e167b74ad5697a9089a35126eb50 # v1
       - name: "Install cargo nextest"
-        uses: taiki-e/install-action@09dc018eee06ae1c9e0409786563f534210ceb83 # v2
+        uses: taiki-e/install-action@83254c543806f3224380bf1001d6fac8feaf2d0b # v2
         with:
           tool: cargo-nextest
       - name: "Install cargo insta"
-        uses: taiki-e/install-action@09dc018eee06ae1c9e0409786563f534210ceb83 # v2
+        uses: taiki-e/install-action@83254c543806f3224380bf1001d6fac8feaf2d0b # v2
         with:
           tool: cargo-insta
       - name: "Run tests"
@@ -320,7 +324,7 @@ jobs:
       - name: "Install Rust toolchain"
         run: rustup show
       - name: "Install cargo nextest"
-        uses: taiki-e/install-action@09dc018eee06ae1c9e0409786563f534210ceb83 # v2
+        uses: taiki-e/install-action@83254c543806f3224380bf1001d6fac8feaf2d0b # v2
         with:
           tool: cargo-nextest
       - name: "Run tests"
@@ -358,9 +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:
@@ -403,11 +407,11 @@ jobs:
       - name: "Install mold"
         uses: rui314/setup-mold@e16410e7f8d9e167b74ad5697a9089a35126eb50 # v1
       - name: "Install cargo nextest"
-        uses: taiki-e/install-action@09dc018eee06ae1c9e0409786563f534210ceb83 # v2
+        uses: taiki-e/install-action@83254c543806f3224380bf1001d6fac8feaf2d0b # v2
         with:
           tool: cargo-nextest
       - name: "Install cargo insta"
-        uses: taiki-e/install-action@09dc018eee06ae1c9e0409786563f534210ceb83 # v2
+        uses: taiki-e/install-action@83254c543806f3224380bf1001d6fac8feaf2d0b # v2
         with:
           tool: cargo-insta
       - name: "Run tests"
@@ -433,7 +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@13f9d60d5358393bf14644dba56d9f123bc5d595 # v1.12.4
         with:
           tool: cargo-fuzz@0.11.2
       - name: "Install cargo-fuzz"
@@ -456,7 +460,7 @@ jobs:
         with:
           persist-credentials: false
       - uses: astral-sh/setup-uv@d4b2f3b6ecc6e67c4457f6d3e41ec42d3d0fcb86 # v5.4.2
-      - uses: actions/download-artifact@95815c38cf2ff2164869cbab79da8d1f422bc89e # v4.2.1
+      - uses: actions/download-artifact@d3f86a106a0bac45b974a628896c90dbdf5c8093 # v4.3.0
         name: Download Ruff binary to test
         id: download-cached-binary
         with:
@@ -521,11 +525,11 @@ 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:
@@ -632,6 +636,53 @@ jobs:
           name: ecosystem-result
           path: ecosystem-result
 
+  fuzz-ty:
+    name: "Fuzz for new ty panics"
+    runs-on: depot-ubuntu-22.04-16
+    needs:
+      - cargo-test-linux
+      - determine_changes
+    # Only runs on pull requests, since that is the only we way we can find the base version for comparison.
+    if: ${{ !contains(github.event.pull_request.labels.*.name, 'no-test') && github.event_name == 'pull_request' && needs.determine_changes.outputs.ty == 'true' }}
+    timeout-minutes: 20
+    steps:
+      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+        with:
+          persist-credentials: false
+      - uses: actions/download-artifact@d3f86a106a0bac45b974a628896c90dbdf5c8093 # v4.3.0
+        name: Download new ty binary
+        id: ty-new
+        with:
+          name: ty
+          path: target/debug
+      - uses: dawidd6/action-download-artifact@20319c5641d495c8a52e688b7dc5fada6c3a9fbc # v8
+        name: Download baseline ty binary
+        with:
+          name: ty
+          branch: ${{ github.event.pull_request.base.ref }}
+          workflow: "ci.yaml"
+          check_artifacts: true
+      - uses: astral-sh/setup-uv@d4b2f3b6ecc6e67c4457f6d3e41ec42d3d0fcb86 # v5.4.2
+      - name: Fuzz
+        env:
+          FORCE_COLOR: 1
+          NEW_TY: ${{ steps.ty-new.outputs.download-path }}
+        run: |
+          # Make executable, since artifact download doesn't preserve this
+          chmod +x "${PWD}/ty" "${NEW_TY}/ty"
+
+          (
+            uvx \
+            --python="${PYTHON_VERSION}" \
+            --from=./python/py-fuzzer \
+            fuzz \
+            --test-executable="${NEW_TY}/ty" \
+            --baseline-executable="${PWD}/ty" \
+            --only-new-bugs \
+            --bin=ty \
+            0-500
+          )
+
   cargo-shear:
     name: "cargo shear"
     runs-on: ubuntu-latest
@@ -641,7 +692,7 @@ 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@13f9d60d5358393bf14644dba56d9f123bc5d595 # v1.12.4
       - run: cargo binstall --no-confirm cargo-shear
       - run: cargo shear
 
@@ -654,7 +705,7 @@ 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
@@ -708,7 +759,7 @@ 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
@@ -779,12 +830,12 @@ 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:
@@ -857,7 +908,7 @@ jobs:
         run: rustup show
 
       - name: "Install codspeed"
-        uses: taiki-e/install-action@09dc018eee06ae1c9e0409786563f534210ceb83 # v2
+        uses: taiki-e/install-action@83254c543806f3224380bf1001d6fac8feaf2d0b # v2
         with:
           tool: cargo-codspeed
 

.github/workflows/daily_property_tests.yaml

@@ -38,17 +38,17 @@ jobs:
       - name: "Install mold"
         uses: rui314/setup-mold@e16410e7f8d9e167b74ad5697a9089a35126eb50 # v1
       - uses: Swatinem/rust-cache@9d47c6ad4b02e050fd481d890b2ea34778fd09d6 # v2.7.8
-      - name: Build Red Knot
+      - name: Build ty
         # 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
+        run: cargo build --locked --release --package ty_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
+            cargo test --locked --release --package ty_python_semantic -- --ignored list::property_tests
+            cargo test --locked --release --package ty_python_semantic -- --ignored types::property_tests::stable
           done
 
   create-issue-on-failure:
@@ -68,5 +68,5 @@ jobs:
               repo: "ruff",
               title: `Daily property test run failed on ${new Date().toDateString()}`,
               body: "Run listed here: https://github.com/${{ github.repository }}/actions/runs/${{ github.run_id }}",
-              labels: ["bug", "red-knot", "testing"],
+              labels: ["bug", "ty", "testing"],
             })

.github/workflows/mypy_primer.yaml

@@ -5,7 +5,7 @@ permissions: {}
 on:
   pull_request:
     paths:
-      - "crates/red_knot*/**"
+      - "crates/ty*/**"
       - "crates/ruff_db"
       - "crates/ruff_python_ast"
       - "crates/ruff_python_parser"
@@ -41,19 +41,20 @@ jobs:
       - uses: Swatinem/rust-cache@9d47c6ad4b02e050fd481d890b2ea34778fd09d6 # v2.7.8
         with:
           workspaces: "ruff"
+
       - name: Install Rust toolchain
         run: rustup show
 
-      - name: Install mypy_primer
-        run: |
-          uv tool install "git+https://github.com/hauntsaninja/mypy_primer@4c22d192a456e27badf85b3ea0f830707375d2b7"
-
       - name: Run mypy_primer
         shell: bash
         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"
@@ -67,9 +68,11 @@ jobs:
 
           echo "Project selector: $PRIMER_SELECTOR"
           # Allow the exit code to be 0 or 1, only fail for actual mypy_primer crashes/bugs
-          uvx mypy_primer \
+          uvx \
+            --from="git+https://github.com/hauntsaninja/mypy_primer@4b15cf3b07db69db67bbfaebfffb2a8a28040933" \
+            mypy_primer \
             --repo ruff \
-            --type-checker knot \
+            --type-checker ty \
             --old base_commit \
             --new "$GITHUB_SHA" \
             --project-selector "/($PRIMER_SELECTOR)\$" \

.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

@@ -23,7 +23,7 @@ jobs:
     steps:
       - name: "Install uv"
         uses: astral-sh/setup-uv@d4b2f3b6ecc6e67c4457f6d3e41ec42d3d0fcb86 # v5.4.2
-      - uses: actions/download-artifact@95815c38cf2ff2164869cbab79da8d1f422bc89e # v4.2.1
+      - 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:
@@ -129,14 +129,14 @@ jobs:
           persist-credentials: false
           submodules: recursive
       - name: Install cached dist
-        uses: actions/download-artifact@95815c38cf2ff2164869cbab79da8d1f422bc89e
+        uses: actions/download-artifact@d3f86a106a0bac45b974a628896c90dbdf5c8093
         with:
           name: cargo-dist-cache
           path: ~/.cargo/bin/
       - run: chmod +x ~/.cargo/bin/dist
       # Get all the local artifacts for the global tasks to use (for e.g. checksums)
       - name: Fetch local artifacts
-        uses: actions/download-artifact@95815c38cf2ff2164869cbab79da8d1f422bc89e
+        uses: actions/download-artifact@d3f86a106a0bac45b974a628896c90dbdf5c8093
         with:
           pattern: artifacts-*
           path: target/distrib/
@@ -180,14 +180,14 @@ jobs:
           persist-credentials: false
           submodules: recursive
       - name: Install cached dist
-        uses: actions/download-artifact@95815c38cf2ff2164869cbab79da8d1f422bc89e
+        uses: actions/download-artifact@d3f86a106a0bac45b974a628896c90dbdf5c8093
         with:
           name: cargo-dist-cache
           path: ~/.cargo/bin/
       - run: chmod +x ~/.cargo/bin/dist
       # Fetch artifacts from scratch-storage
       - name: Fetch artifacts
-        uses: actions/download-artifact@95815c38cf2ff2164869cbab79da8d1f422bc89e
+        uses: actions/download-artifact@d3f86a106a0bac45b974a628896c90dbdf5c8093
         with:
           pattern: artifacts-*
           path: target/distrib/
@@ -257,7 +257,7 @@ jobs:
           submodules: recursive
       # Create a GitHub Release while uploading all files to it
       - name: "Download GitHub Artifacts"
-        uses: actions/download-artifact@95815c38cf2ff2164869cbab79da8d1f422bc89e
+        uses: actions/download-artifact@d3f86a106a0bac45b974a628896c90dbdf5c8093
         with:
           pattern: artifacts-*
           path: artifacts

.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"],
             })

.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/.*|
@@ -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: v0.11.6
+    rev: v0.11.9
     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 +1,73 @@
 # Changelog
 
+## 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
+
+- \[`airflow`\] Apply auto fixes to cases where the names have changed in Airflow 3 (`AIR302`, `AIR311`) ([#17553](https://github.com/astral-sh/ruff/pull/17553), [#17570](https://github.com/astral-sh/ruff/pull/17570), [#17571](https://github.com/astral-sh/ruff/pull/17571))
+- \[`airflow`\] Extend `AIR301` rule ([#17598](https://github.com/astral-sh/ruff/pull/17598))
+- \[`airflow`\] Update existing `AIR302` rules with better suggestions ([#17542](https://github.com/astral-sh/ruff/pull/17542))
+- \[`refurb`\] Mark fix as safe for `readlines-in-for` (`FURB129`) ([#17644](https://github.com/astral-sh/ruff/pull/17644))
+- [syntax-errors] `nonlocal` declaration at module level ([#17559](https://github.com/astral-sh/ruff/pull/17559))
+- [syntax-errors] Detect single starred expression assignment `x = *y` ([#17624](https://github.com/astral-sh/ruff/pull/17624))
+
+### Bug fixes
+
+- \[`flake8-pyi`\] Ensure `Literal[None,] | Literal[None,]` is not autofixed to `None | None` (`PYI061`) ([#17659](https://github.com/astral-sh/ruff/pull/17659))
+- \[`flake8-use-pathlib`\] Avoid suggesting `Path.iterdir()` for `os.listdir` with file descriptor (`PTH208`) ([#17715](https://github.com/astral-sh/ruff/pull/17715))
+- \[`flake8-use-pathlib`\] Fix `PTH104` false positive when `rename` is passed a file descriptor ([#17712](https://github.com/astral-sh/ruff/pull/17712))
+- \[`flake8-use-pathlib`\] Fix `PTH116` false positive when `stat` is passed a file descriptor ([#17709](https://github.com/astral-sh/ruff/pull/17709))
+- \[`flake8-use-pathlib`\] Fix `PTH123` false positive when `open` is passed a file descriptor from a function call ([#17705](https://github.com/astral-sh/ruff/pull/17705))
+- \[`pycodestyle`\] Fix duplicated diagnostic in `E712` ([#17651](https://github.com/astral-sh/ruff/pull/17651))
+- \[`pylint`\] Detect `global` declarations in module scope (`PLE0118`) ([#17411](https://github.com/astral-sh/ruff/pull/17411))
+- [syntax-errors] Make `async-comprehension-in-sync-comprehension` more specific ([#17460](https://github.com/astral-sh/ruff/pull/17460))
+
+### Configuration
+
+- Add option to disable `typing_extensions` imports ([#17611](https://github.com/astral-sh/ruff/pull/17611))
+
+### Documentation
+
+- Fix example syntax for the `lint.pydocstyle.ignore-var-parameters` option ([#17740](https://github.com/astral-sh/ruff/pull/17740))
+- Add fix safety sections (`ASYNC116`, `FLY002`, `D200`, `RUF005`, `RUF017`, `RUF027`, `RUF028`, `RUF057`) ([#17497](https://github.com/astral-sh/ruff/pull/17497), [#17496](https://github.com/astral-sh/ruff/pull/17496), [#17502](https://github.com/astral-sh/ruff/pull/17502), [#17484](https://github.com/astral-sh/ruff/pull/17484), [#17480](https://github.com/astral-sh/ruff/pull/17480), [#17485](https://github.com/astral-sh/ruff/pull/17485), [#17722](https://github.com/astral-sh/ruff/pull/17722), [#17483](https://github.com/astral-sh/ruff/pull/17483))
+
+### Other changes
+
+- Add Python 3.14 to configuration options ([#17647](https://github.com/astral-sh/ruff/pull/17647))
+- Make syntax error for unparenthesized except tuples version specific to before 3.14 ([#17660](https://github.com/astral-sh/ruff/pull/17660))
+
 ## 0.11.7
 
 ### Preview features

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

@@ -366,6 +366,15 @@ 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:

Cargo.toml

@@ -23,6 +23,7 @@ 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 +36,15 @@ 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" }
@@ -124,7 +126,7 @@ rayon = { version = "1.10.0" }
 regex = { version = "1.10.2" }
 rustc-hash = { version = "2.0.0" }
 # When updating salsa, make sure to also update the revision in `fuzz/Cargo.toml`
-salsa = { git = "https://github.com/salsa-rs/salsa.git", rev = "87bf6b6c2d5f6479741271da73bd9d30c2580c26" }
+salsa = { git = "https://github.com/salsa-rs/salsa.git", rev = "7edce6e248f35c8114b4b021cdb474a3fb2813b3" }
 schemars = { version = "0.8.16" }
 seahash = { version = "4.1.0" }
 serde = { version = "1.0.197", features = ["derive"] }
@@ -182,7 +184,7 @@ 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]
@@ -231,10 +233,6 @@ unused_peekable = "warn"
 # Diagnostics are not actionable: Enable once https://github.com/rust-lang/rust-clippy/issues/13774 is resolved.
 large_stack_arrays = "allow"
 
-# Salsa generates functions with parameters for each field of a `salsa::interned` struct.
-# If we don't allow this, we get warnings for structs with too many fields.
-too_many_arguments = "allow"
-
 [profile.release]
 # Note that we set these explicitly, and these values
 # were chosen based on a trade-off between compile times
@@ -272,75 +270,3 @@ 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" = "95815c38cf2ff2164869cbab79da8d1f422bc89e" # v4.2.1
-"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/0.11.7/install.sh | sh
-powershell -c "irm https://astral.sh/ruff/0.11.7/install.ps1 | iex"
+curl -LsSf https://astral.sh/ruff/0.11.9/install.sh | sh
+powershell -c "irm https://astral.sh/ruff/0.11.9/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: v0.11.7
+  rev: v0.11.9
   hooks:
     # Run the linter.
     - id: ruff

_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/**/*",
 ]

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/any.md

@@ -1,102 +0,0 @@
-# Any
-
-## Annotation
-
-`typing.Any` is a way to name the Any type.
-
-```py
-from typing import Any
-
-x: Any = 1
-x = "foo"
-
-def f():
-    reveal_type(x)  # revealed: Any
-```
-
-## Aliased to a different name
-
-If you alias `typing.Any` to another name, we still recognize that as a spelling of the Any type.
-
-```py
-from typing import Any as RenamedAny
-
-x: RenamedAny = 1
-x = "foo"
-
-def f():
-    reveal_type(x)  # revealed: Any
-```
-
-## Shadowed class
-
-If you define your own class named `Any`, using that in a type expression refers to your class, and
-isn't a spelling of the Any type.
-
-```py
-class Any: ...
-
-x: Any
-
-def f():
-    reveal_type(x)  # revealed: Any
-
-# This verifies that we're not accidentally seeing typing.Any, since str is assignable
-# to that but not to our locally defined class.
-y: Any = "not an Any"  # error: [invalid-assignment]
-```
-
-## Subclass
-
-The spec allows you to define subclasses of `Any`.
-
-`Subclass` has an unknown superclass, which might be `int`. The assignment to `x` should not be
-allowed, even when the unknown superclass is `int`. The assignment to `y` should be allowed, since
-`Subclass` might have `int` as a superclass, and is therefore assignable to `int`.
-
-```py
-from typing import Any
-
-class Subclass(Any): ...
-
-reveal_type(Subclass.__mro__)  # revealed: tuple[Literal[Subclass], Any, Literal[object]]
-
-x: Subclass = 1  # error: [invalid-assignment]
-y: int = Subclass()
-
-def _(s: Subclass):
-    reveal_type(s)  # revealed: Subclass
-```
-
-`Subclass` should not be assignable to a final class though, because `Subclass` could not possibly
-be a subclass of `FinalClass`:
-
-```py
-from typing import final
-
-@final
-class FinalClass: ...
-
-f: FinalClass = Subclass()  # error: [invalid-assignment]
-```
-
-A use case where this comes up is with mocking libraries, where the mock object should be assignable
-to any type:
-
-```py
-from unittest.mock import MagicMock
-
-x: int = MagicMock()
-```
-
-## Invalid
-
-`Any` cannot be parameterized:
-
-```py
-from typing import Any
-
-# error: [invalid-type-form] "Type `typing.Any` expected no type parameter"
-def f(x: Any[int]):
-    reveal_type(x)  # revealed: Unknown
-```

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/semantic_syntax_errors.md

@@ -1,165 +0,0 @@
-# Semantic syntax error diagnostics
-
-## `async` comprehensions in synchronous comprehensions
-
-### Python 3.10
-
-<!-- snapshot-diagnostics -->
-
-Before Python 3.11, `async` comprehensions could not be used within outer sync comprehensions, even
-within an `async` function ([CPython issue](https://github.com/python/cpython/issues/77527)):
-
-```toml
-[environment]
-python-version = "3.10"
-```
-
-```py
-async def elements(n):
-    yield n
-
-async def f():
-    # error: 19 [invalid-syntax] "cannot use an asynchronous comprehension inside of a synchronous comprehension on Python 3.10 (syntax was added in 3.11)"
-    return {n: [x async for x in elements(n)] for n in range(3)}
-```
-
-If all of the comprehensions are `async`, on the other hand, the code was still valid:
-
-```py
-async def test():
-    return [[x async for x in elements(n)] async for n in range(3)]
-```
-
-These are a couple of tricky but valid cases to check that nested scope handling is wired up
-correctly in the `SemanticSyntaxContext` trait:
-
-```py
-async def f():
-    [x for x in [1]] and [x async for x in elements(1)]
-
-async def f():
-    def g():
-        pass
-    [x async for x in elements(1)]
-```
-
-### Python 3.11
-
-All of these same examples are valid after Python 3.11:
-
-```toml
-[environment]
-python-version = "3.11"
-```
-
-```py
-async def elements(n):
-    yield n
-
-async def f():
-    return {n: [x async for x in elements(n)] for n in range(3)}
-```
-
-## Late `__future__` import
-
-```py
-from collections import namedtuple
-
-# error: [invalid-syntax] "__future__ imports must be at the top of the file"
-from __future__ import print_function
-```
-
-## Invalid annotation
-
-This one might be a bit redundant with the `invalid-type-form` error.
-
-```toml
-[environment]
-python-version = "3.12"
-```
-
-```py
-from __future__ import annotations
-
-# error: [invalid-type-form] "Named expressions are not allowed in type expressions"
-# error: [invalid-syntax] "named expression cannot be used within a type annotation"
-def f() -> (y := 3): ...
-```
-
-## Duplicate `match` key
-
-```toml
-[environment]
-python-version = "3.10"
-```
-
-```py
-match 2:
-    # error: [invalid-syntax] "mapping pattern checks duplicate key `"x"`"
-    case {"x": 1, "x": 2}:
-        ...
-```
-
-## `return`, `yield`, `yield from`, and `await` outside function
-
-```py
-# error: [invalid-syntax] "`return` statement outside of a function"
-return
-
-# error: [invalid-syntax] "`yield` statement outside of a function"
-yield
-
-# error: [invalid-syntax] "`yield from` statement outside of a function"
-yield from []
-
-# error: [invalid-syntax] "`await` statement outside of a function"
-# error: [invalid-syntax] "`await` outside of an asynchronous function"
-await 1
-
-def f():
-    # error: [invalid-syntax] "`await` outside of an asynchronous function"
-    await 1
-```
-
-Generators are evaluated lazily, so `await` is allowed, even outside of a function.
-
-```py
-async def g():
-    yield 1
-
-(x async for x in g())
-```
-
-## `await` outside async function
-
-This error includes `await`, `async for`, `async with`, and `async` comprehensions.
-
-```python
-async def elements(n):
-    yield n
-
-def _():
-    # error: [invalid-syntax] "`await` outside of an asynchronous function"
-    await 1
-    # error: [invalid-syntax] "`async for` outside of an asynchronous function"
-    async for _ in elements(1):
-        ...
-    # error: [invalid-syntax] "`async with` outside of an asynchronous function"
-    async with elements(1) as x:
-        ...
-    # error: [invalid-syntax] "cannot use an asynchronous comprehension outside of an asynchronous function on Python 3.9 (syntax was added in 3.11)"
-    # error: [invalid-syntax] "asynchronous comprehension outside of an asynchronous function"
-    [x async for x in elements(1)]
-```
-
-## Load before `global` declaration
-
-This should be an error, but it's not yet.
-
-TODO implement `SemanticSyntaxContext::global`
-
-```py
-def f():
-    x = 1
-    global x
-```

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

@@ -1,72 +0,0 @@
-# Legacy type variables
-
-The tests in this file focus on how type variables are defined using the legacy notation. Most
-_uses_ of type variables are tested in other files in this directory; we do not duplicate every test
-for both type variable syntaxes.
-
-Unless otherwise specified, all quotations come from the [Generics] section of the typing spec.
-
-## Type variables
-
-### Defining legacy type variables
-
-> Generics can be parameterized by using a factory available in `typing` called `TypeVar`.
-
-This was the only way to create type variables prior to PEP 695/Python 3.12. It is still available
-in newer Python releases.
-
-```py
-from typing import TypeVar
-
-T = TypeVar("T")
-```
-
-### Directly assigned to a variable
-
-> A `TypeVar()` expression must always directly be assigned to a variable (it should not be used as
-> part of a larger expression).
-
-```py
-from typing import TypeVar
-
-# TODO: error
-TestList = list[TypeVar("W")]
-```
-
-### `TypeVar` parameter must match variable name
-
-> The argument to `TypeVar()` must be a string equal to the variable name to which it is assigned.
-
-```py
-from typing import TypeVar
-
-# TODO: error
-T = TypeVar("Q")
-```
-
-### No redefinition
-
-> Type variables must not be redefined.
-
-```py
-from typing import TypeVar
-
-T = TypeVar("T")
-
-# TODO: error
-T = TypeVar("T")
-```
-
-### Cannot have only one constraint
-
-> `TypeVar` supports constraining parametric types to a fixed set of possible types...There should
-> be at least two constraints, if any; specifying a single constraint is disallowed.
-
-```py
-from typing import TypeVar
-
-# TODO: error: [invalid-type-variable-constraints]
-T = TypeVar("T", int)
-```
-
-[generics]: https://typing.python.org/en/latest/spec/generics.html

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/assert.md

@@ -1,53 +0,0 @@
-# Narrowing with assert statements
-
-## `assert` a value `is None` or `is not None`
-
-```py
-def _(x: str | None, y: str | None):
-    assert x is not None
-    reveal_type(x)  # revealed: str
-    assert y is None
-    reveal_type(y)  # revealed: None
-```
-
-## `assert` a value is truthy or falsy
-
-```py
-def _(x: bool, y: bool):
-    assert x
-    reveal_type(x)  # revealed: Literal[True]
-    assert not y
-    reveal_type(y)  # revealed: Literal[False]
-```
-
-## `assert` with `is` and `==` for literals
-
-```py
-from typing import Literal
-
-def _(x: Literal[1, 2, 3], y: Literal[1, 2, 3]):
-    assert x is 2
-    reveal_type(x)  # revealed: Literal[2]
-    assert y == 2
-    reveal_type(y)  # revealed: Literal[2]
-```
-
-## `assert` with `isinstance`
-
-```py
-def _(x: int | str):
-    assert isinstance(x, int)
-    reveal_type(x)  # revealed: int
-```
-
-## `assert` a value `in` a tuple
-
-```py
-from typing import Literal
-
-def _(x: Literal[1, 2, 3], y: Literal[1, 2, 3]):
-    assert x in (1, 2)
-    reveal_type(x)  # revealed: Literal[1, 2]
-    assert y not in (1, 2)
-    reveal_type(y)  # revealed: Literal[3]
-```

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/protocols.md_-_Protocols_-_Calls_to_protocol_classes.snap

@@ -1,117 +0,0 @@
----
-source: crates/red_knot_test/src/lib.rs
-expression: snapshot
----
----
-mdtest name: protocols.md - Protocols - Calls to protocol classes
-mdtest path: crates/red_knot_python_semantic/resources/mdtest/protocols.md
----
-
-# Python source files
-
-## mdtest_snippet.py
-
-```
- 1 | from typing_extensions import Protocol, reveal_type
- 2 | 
- 3 | # error: [call-non-callable]
- 4 | reveal_type(Protocol())  # revealed: Unknown
- 5 | 
- 6 | class MyProtocol(Protocol):
- 7 |     x: int
- 8 | 
- 9 | # error: [call-non-callable] "Cannot instantiate class `MyProtocol`"
-10 | reveal_type(MyProtocol())  # revealed: MyProtocol
-11 | class SubclassOfMyProtocol(MyProtocol): ...
-12 | 
-13 | reveal_type(SubclassOfMyProtocol())  # revealed: SubclassOfMyProtocol
-14 | def f(x: type[MyProtocol]):
-15 |     reveal_type(x())  # revealed: MyProtocol
-```
-
-# Diagnostics
-
-```
-error: lint:call-non-callable: Object of type `typing.Protocol` is not callable
- --> /src/mdtest_snippet.py:4:13
-  |
-3 | # error: [call-non-callable]
-4 | reveal_type(Protocol())  # revealed: Unknown
-  |             ^^^^^^^^^^
-5 |
-6 | class MyProtocol(Protocol):
-  |
-
-```
-
-```
-info: revealed-type: Revealed type
- --> /src/mdtest_snippet.py:4:1
-  |
-3 | # error: [call-non-callable]
-4 | reveal_type(Protocol())  # revealed: Unknown
-  | ^^^^^^^^^^^^^^^^^^^^^^^ `Unknown`
-5 |
-6 | class MyProtocol(Protocol):
-  |
-
-```
-
-```
-error: lint:call-non-callable: Cannot instantiate class `MyProtocol`
-  --> /src/mdtest_snippet.py:10:13
-   |
- 9 | # error: [call-non-callable] "Cannot instantiate class `MyProtocol`"
-10 | reveal_type(MyProtocol())  # revealed: MyProtocol
-   |             ^^^^^^^^^^^^ This call will raise `TypeError` at runtime
-11 | class SubclassOfMyProtocol(MyProtocol): ...
-   |
-info: Protocol classes cannot be instantiated
- --> /src/mdtest_snippet.py:6:7
-  |
-4 | reveal_type(Protocol())  # revealed: Unknown
-5 |
-6 | class MyProtocol(Protocol):
-  |       ^^^^^^^^^^^^^^^^^^^^ `MyProtocol` declared as a protocol here
-7 |     x: int
-  |
-
-```
-
-```
-info: revealed-type: Revealed type
-  --> /src/mdtest_snippet.py:10:1
-   |
- 9 | # error: [call-non-callable] "Cannot instantiate class `MyProtocol`"
-10 | reveal_type(MyProtocol())  # revealed: MyProtocol
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^ `MyProtocol`
-11 | class SubclassOfMyProtocol(MyProtocol): ...
-   |
-
-```
-
-```
-info: revealed-type: Revealed type
-  --> /src/mdtest_snippet.py:13:1
-   |
-11 | class SubclassOfMyProtocol(MyProtocol): ...
-12 |
-13 | reveal_type(SubclassOfMyProtocol())  # revealed: SubclassOfMyProtocol
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ `SubclassOfMyProtocol`
-14 | def f(x: type[MyProtocol]):
-15 |     reveal_type(x())  # revealed: MyProtocol
-   |
-
-```
-
-```
-info: revealed-type: Revealed type
-  --> /src/mdtest_snippet.py:15:5
-   |
-13 | reveal_type(SubclassOfMyProtocol())  # revealed: SubclassOfMyProtocol
-14 | def f(x: type[MyProtocol]):
-15 |     reveal_type(x())  # revealed: MyProtocol
-   |     ^^^^^^^^^^^^^^^^ `MyProtocol`
-   |
-
-```

crates/red_knot_python_semantic/resources/mdtest/snapshots/unpacking.md_-_Unpacking_-_Right_hand_side_not_iterable.snap

@@ -1,28 +0,0 @@
----
-source: crates/red_knot_test/src/lib.rs
-expression: snapshot
----
----
-mdtest name: unpacking.md - Unpacking - Right hand side not iterable
-mdtest path: crates/red_knot_python_semantic/resources/mdtest/diagnostics/unpacking.md
----
-
-# Python source files
-
-## mdtest_snippet.py
-
-```
-1 | a, b = 1  # error: [not-iterable]
-```
-
-# Diagnostics
-
-```
-error: lint:not-iterable: Object of type `Literal[1]` is not iterable because it doesn't have an `__iter__` method or a `__getitem__` method
- --> /src/mdtest_snippet.py:1:8
-  |
-1 | a, b = 1  # error: [not-iterable]
-  |        ^
-  |
-
-```

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_python_semantic/src/types/generics.rs

@@ -1,408 +0,0 @@
-use ruff_python_ast as ast;
-use rustc_hash::FxHashMap;
-
-use crate::semantic_index::SemanticIndex;
-use crate::types::signatures::{Parameter, Parameters, Signature};
-use crate::types::{
-    declaration_type, KnownInstanceType, Type, TypeVarBoundOrConstraints, TypeVarInstance,
-    UnionBuilder, UnionType,
-};
-use crate::Db;
-
-/// A list of formal type variables for a generic function, class, or type alias.
-///
-/// TODO: Handle nested generic contexts better, with actual parent links to the lexically
-/// containing context.
-#[salsa::interned(debug)]
-pub struct GenericContext<'db> {
-    #[return_ref]
-    pub(crate) variables: Box<[TypeVarInstance<'db>]>,
-}
-
-impl<'db> GenericContext<'db> {
-    pub(crate) fn from_type_params(
-        db: &'db dyn Db,
-        index: &'db SemanticIndex<'db>,
-        type_params_node: &ast::TypeParams,
-    ) -> Self {
-        let variables: Box<[_]> = type_params_node
-            .iter()
-            .filter_map(|type_param| Self::variable_from_type_param(db, index, type_param))
-            .collect();
-        Self::new(db, variables)
-    }
-
-    fn variable_from_type_param(
-        db: &'db dyn Db,
-        index: &'db SemanticIndex<'db>,
-        type_param_node: &ast::TypeParam,
-    ) -> Option<TypeVarInstance<'db>> {
-        match type_param_node {
-            ast::TypeParam::TypeVar(node) => {
-                let definition = index.expect_single_definition(node);
-                let Type::KnownInstance(KnownInstanceType::TypeVar(typevar)) =
-                    declaration_type(db, definition).inner_type()
-                else {
-                    panic!("typevar should be inferred as a TypeVarInstance");
-                };
-                Some(typevar)
-            }
-            // TODO: Support these!
-            ast::TypeParam::ParamSpec(_) => None,
-            ast::TypeParam::TypeVarTuple(_) => None,
-        }
-    }
-
-    pub(crate) fn signature(self, db: &'db dyn Db) -> Signature<'db> {
-        let parameters = Parameters::new(
-            self.variables(db)
-                .iter()
-                .map(|typevar| Self::parameter_from_typevar(db, *typevar)),
-        );
-        Signature::new(parameters, None)
-    }
-
-    fn parameter_from_typevar(db: &'db dyn Db, typevar: TypeVarInstance<'db>) -> Parameter<'db> {
-        let mut parameter = Parameter::positional_only(Some(typevar.name(db).clone()));
-        match typevar.bound_or_constraints(db) {
-            Some(TypeVarBoundOrConstraints::UpperBound(bound)) => {
-                // TODO: This should be a type form.
-                parameter = parameter.with_annotated_type(bound);
-            }
-            Some(TypeVarBoundOrConstraints::Constraints(constraints)) => {
-                // TODO: This should be a new type variant where only these exact types are
-                // assignable, and not subclasses of them, nor a union of them.
-                parameter = parameter
-                    .with_annotated_type(UnionType::from_elements(db, constraints.iter(db)));
-            }
-            None => {}
-        }
-        parameter
-    }
-
-    pub(crate) fn default_specialization(self, db: &'db dyn Db) -> Specialization<'db> {
-        let types = self
-            .variables(db)
-            .iter()
-            .map(|typevar| typevar.default_ty(db).unwrap_or(Type::unknown()))
-            .collect();
-        self.specialize(db, types)
-    }
-
-    pub(crate) fn identity_specialization(self, db: &'db dyn Db) -> Specialization<'db> {
-        let types = self
-            .variables(db)
-            .iter()
-            .map(|typevar| Type::TypeVar(*typevar))
-            .collect();
-        self.specialize(db, types)
-    }
-
-    pub(crate) fn unknown_specialization(self, db: &'db dyn Db) -> Specialization<'db> {
-        let types = vec![Type::unknown(); self.variables(db).len()];
-        self.specialize(db, types.into())
-    }
-
-    pub(crate) fn specialize(
-        self,
-        db: &'db dyn Db,
-        types: Box<[Type<'db>]>,
-    ) -> Specialization<'db> {
-        Specialization::new(db, self, types)
-    }
-}
-
-/// An assignment of a specific type to each type variable in a generic scope.
-///
-/// TODO: Handle nested specializations better, with actual parent links to the specialization of
-/// the lexically containing context.
-#[salsa::interned(debug)]
-pub struct Specialization<'db> {
-    pub(crate) generic_context: GenericContext<'db>,
-    #[return_ref]
-    pub(crate) types: Box<[Type<'db>]>,
-}
-
-impl<'db> Specialization<'db> {
-    /// Applies a specialization to this specialization. This is used, for instance, when a generic
-    /// class inherits from a generic alias:
-    ///
-    /// ```py
-    /// class A[T]: ...
-    /// class B[U](A[U]): ...
-    /// ```
-    ///
-    /// `B` is a generic class, whose MRO includes the generic alias `A[U]`, which specializes `A`
-    /// with the specialization `{T: U}`. If `B` is specialized to `B[int]`, with specialization
-    /// `{U: int}`, we can apply the second specialization to the first, resulting in `T: int`.
-    /// That lets us produce the generic alias `A[int]`, which is the corresponding entry in the
-    /// MRO of `B[int]`.
-    pub(crate) fn apply_specialization(self, db: &'db dyn Db, other: Specialization<'db>) -> Self {
-        let types: Box<[_]> = self
-            .types(db)
-            .into_iter()
-            .map(|ty| ty.apply_specialization(db, other))
-            .collect();
-        Specialization::new(db, self.generic_context(db), types)
-    }
-
-    /// Combines two specializations of the same generic context. If either specialization maps a
-    /// typevar to `Type::Unknown`, the other specialization's mapping is used. If both map the
-    /// typevar to a known type, those types are unioned together.
-    ///
-    /// Panics if the two specializations are not for the same generic context.
-    pub(crate) fn combine(self, db: &'db dyn Db, other: Self) -> Self {
-        let generic_context = self.generic_context(db);
-        assert!(other.generic_context(db) == generic_context);
-        // TODO special-casing Unknown to mean "no mapping" is not right here, and can give
-        // confusing/wrong results in cases where there was a mapping found for a typevar, and it
-        // was of type Unknown. We should probably add a bitset or similar to Specialization that
-        // explicitly tells us which typevars are mapped.
-        let types: Box<[_]> = self
-            .types(db)
-            .into_iter()
-            .zip(other.types(db))
-            .map(|(self_type, other_type)| match (self_type, other_type) {
-                (unknown, known) | (known, unknown) if unknown.is_unknown() => *known,
-                _ => UnionType::from_elements(db, [self_type, other_type]),
-            })
-            .collect();
-        Specialization::new(db, self.generic_context(db), types)
-    }
-
-    pub(crate) fn normalized(self, db: &'db dyn Db) -> Self {
-        let types: Box<[_]> = self.types(db).iter().map(|ty| ty.normalized(db)).collect();
-        Self::new(db, self.generic_context(db), types)
-    }
-
-    /// Returns the type that a typevar is specialized to, or None if the typevar isn't part of
-    /// this specialization.
-    pub(crate) fn get(self, db: &'db dyn Db, typevar: TypeVarInstance<'db>) -> Option<Type<'db>> {
-        self.generic_context(db)
-            .variables(db)
-            .into_iter()
-            .zip(self.types(db))
-            .find(|(var, _)| **var == typevar)
-            .map(|(_, ty)| *ty)
-    }
-
-    pub(crate) fn is_subtype_of(self, db: &'db dyn Db, other: Specialization<'db>) -> bool {
-        let generic_context = self.generic_context(db);
-        if generic_context != other.generic_context(db) {
-            return false;
-        }
-
-        for ((_typevar, self_type), other_type) in (generic_context.variables(db).into_iter())
-            .zip(self.types(db))
-            .zip(other.types(db))
-        {
-            if matches!(self_type, Type::Dynamic(_)) || matches!(other_type, Type::Dynamic(_)) {
-                return false;
-            }
-
-            // TODO: We currently treat all typevars as invariant. Once we track the actual
-            // variance of each typevar, these checks should change:
-            //   - covariant: verify that self_type <: other_type
-            //   - contravariant: verify that other_type <: self_type
-            //   - invariant: verify that self_type == other_type
-            //   - bivariant: skip, can't make subtyping false
-            if !self_type.is_equivalent_to(db, *other_type) {
-                return false;
-            }
-        }
-
-        true
-    }
-
-    pub(crate) fn is_equivalent_to(self, db: &'db dyn Db, other: Specialization<'db>) -> bool {
-        let generic_context = self.generic_context(db);
-        if generic_context != other.generic_context(db) {
-            return false;
-        }
-
-        for ((_typevar, self_type), other_type) in (generic_context.variables(db).into_iter())
-            .zip(self.types(db))
-            .zip(other.types(db))
-        {
-            if matches!(self_type, Type::Dynamic(_)) || matches!(other_type, Type::Dynamic(_)) {
-                return false;
-            }
-
-            // TODO: We currently treat all typevars as invariant. Once we track the actual
-            // variance of each typevar, these checks should change:
-            //   - covariant: verify that self_type == other_type
-            //   - contravariant: verify that other_type == self_type
-            //   - invariant: verify that self_type == other_type
-            //   - bivariant: skip, can't make equivalence false
-            if !self_type.is_equivalent_to(db, *other_type) {
-                return false;
-            }
-        }
-
-        true
-    }
-
-    pub(crate) fn is_assignable_to(self, db: &'db dyn Db, other: Specialization<'db>) -> bool {
-        let generic_context = self.generic_context(db);
-        if generic_context != other.generic_context(db) {
-            return false;
-        }
-
-        for ((_typevar, self_type), other_type) in (generic_context.variables(db).into_iter())
-            .zip(self.types(db))
-            .zip(other.types(db))
-        {
-            if matches!(self_type, Type::Dynamic(_)) || matches!(other_type, Type::Dynamic(_)) {
-                continue;
-            }
-
-            // TODO: We currently treat all typevars as invariant. Once we track the actual
-            // variance of each typevar, these checks should change:
-            //   - covariant: verify that self_type <: other_type
-            //   - contravariant: verify that other_type <: self_type
-            //   - invariant: verify that self_type == other_type
-            //   - bivariant: skip, can't make assignability false
-            if !self_type.is_gradual_equivalent_to(db, *other_type) {
-                return false;
-            }
-        }
-
-        true
-    }
-
-    pub(crate) fn is_gradual_equivalent_to(
-        self,
-        db: &'db dyn Db,
-        other: Specialization<'db>,
-    ) -> bool {
-        let generic_context = self.generic_context(db);
-        if generic_context != other.generic_context(db) {
-            return false;
-        }
-
-        for ((_typevar, self_type), other_type) in (generic_context.variables(db).into_iter())
-            .zip(self.types(db))
-            .zip(other.types(db))
-        {
-            // TODO: We currently treat all typevars as invariant. Once we track the actual
-            // variance of each typevar, these checks should change:
-            //   - covariant: verify that self_type == other_type
-            //   - contravariant: verify that other_type == self_type
-            //   - invariant: verify that self_type == other_type
-            //   - bivariant: skip, can't make equivalence false
-            if !self_type.is_gradual_equivalent_to(db, *other_type) {
-                return false;
-            }
-        }
-
-        true
-    }
-}
-
-/// Performs type inference between parameter annotations and argument types, producing a
-/// specialization of a generic function.
-pub(crate) struct SpecializationBuilder<'db> {
-    db: &'db dyn Db,
-    types: FxHashMap<TypeVarInstance<'db>, UnionBuilder<'db>>,
-}
-
-impl<'db> SpecializationBuilder<'db> {
-    pub(crate) fn new(db: &'db dyn Db) -> Self {
-        Self {
-            db,
-            types: FxHashMap::default(),
-        }
-    }
-
-    pub(crate) fn build(&mut self, generic_context: GenericContext<'db>) -> Specialization<'db> {
-        let types: Box<[_]> = generic_context
-            .variables(self.db)
-            .iter()
-            .map(|variable| {
-                self.types
-                    .remove(variable)
-                    .map(UnionBuilder::build)
-                    .unwrap_or(variable.default_ty(self.db).unwrap_or(Type::unknown()))
-            })
-            .collect();
-        Specialization::new(self.db, generic_context, types)
-    }
-
-    fn add_type_mapping(&mut self, typevar: TypeVarInstance<'db>, ty: Type<'db>) {
-        let builder = self
-            .types
-            .entry(typevar)
-            .or_insert_with(|| UnionBuilder::new(self.db));
-        builder.add_in_place(ty);
-    }
-
-    pub(crate) fn infer(&mut self, formal: Type<'db>, actual: Type<'db>) {
-        // If the actual type is already assignable to the formal type, then return without adding
-        // any new type mappings. (Note that if the formal type contains any typevars, this check
-        // will fail, since no non-typevar types are assignable to a typevar.)
-        //
-        // In particular, this handles a case like
-        //
-        // ```py
-        // def f[T](t: T | None): ...
-        //
-        // f(None)
-        // ```
-        //
-        // without specializing `T` to `None`.
-        if actual.is_assignable_to(self.db, formal) {
-            return;
-        }
-
-        match (formal, actual) {
-            (Type::TypeVar(typevar), _) => self.add_type_mapping(typevar, actual),
-
-            (Type::Tuple(formal_tuple), Type::Tuple(actual_tuple)) => {
-                let formal_elements = formal_tuple.elements(self.db);
-                let actual_elements = actual_tuple.elements(self.db);
-                if formal_elements.len() == actual_elements.len() {
-                    for (formal_element, actual_element) in
-                        formal_elements.iter().zip(actual_elements)
-                    {
-                        self.infer(*formal_element, *actual_element);
-                    }
-                }
-            }
-
-            (Type::Union(formal), _) => {
-                // TODO: We haven't implemented a full unification solver yet. If typevars appear
-                // in multiple union elements, we ideally want to express that _only one_ of them
-                // needs to match, and that we should infer the smallest type mapping that allows
-                // that.
-                //
-                // For now, we punt on handling multiple typevar elements. Instead, if _precisely
-                // one_ union element _is_ a typevar (not _contains_ a typevar), then we go ahead
-                // and add a mapping between that typevar and the actual type. (Note that we've
-                // already handled above the case where the actual is assignable to a _non-typevar_
-                // union element.)
-                let mut typevars = formal.iter(self.db).filter_map(|ty| match ty {
-                    Type::TypeVar(typevar) => Some(*typevar),
-                    _ => None,
-                });
-                let typevar = typevars.next();
-                let additional_typevars = typevars.next();
-                if let (Some(typevar), None) = (typevar, additional_typevars) {
-                    self.add_type_mapping(typevar, actual);
-                }
-            }
-
-            (Type::Intersection(formal), _) => {
-                // The actual type must be assignable to every (positive) element of the
-                // formal intersection, so we must infer type mappings for each of them. (The
-                // actual type must also be disjoint from every negative element of the
-                // intersection, but that doesn't help us infer any type mappings.)
-                for positive in formal.iter_positive(self.db) {
-                    self.infer(positive, actual);
-                }
-            }
-
-            // TODO: Add more forms that we can structurally induct into: type[C], callables
-            _ => {}
-        }
-    }
-}

crates/red_knot_python_semantic/src/types/instance.rs

@@ -1,94 +0,0 @@
-//! Instance types: both nominal and structural.
-
-use super::{ClassType, KnownClass, SubclassOfType, Type};
-use crate::Db;
-
-impl<'db> Type<'db> {
-    pub(crate) const fn instance(class: ClassType<'db>) -> Self {
-        Self::Instance(InstanceType { class })
-    }
-
-    pub(crate) const fn into_instance(self) -> Option<InstanceType<'db>> {
-        match self {
-            Type::Instance(instance_type) => Some(instance_type),
-            _ => None,
-        }
-    }
-}
-
-/// A type representing the set of runtime objects which are instances of a certain nominal class.
-#[derive(Copy, Clone, Debug, Eq, PartialEq, Hash, salsa::Update)]
-pub struct InstanceType<'db> {
-    // Keep this field private, so that the only way of constructing `InstanceType` instances
-    // is through the `Type::instance` constructor function.
-    class: ClassType<'db>,
-}
-
-impl<'db> InstanceType<'db> {
-    pub(super) fn class(self) -> ClassType<'db> {
-        self.class
-    }
-
-    pub(super) fn is_subtype_of(self, db: &'db dyn Db, other: Self) -> bool {
-        // N.B. The subclass relation is fully static
-        self.class.is_subclass_of(db, other.class)
-    }
-
-    pub(super) fn is_equivalent_to(self, db: &'db dyn Db, other: Self) -> bool {
-        self.class.is_equivalent_to(db, other.class)
-    }
-
-    pub(super) fn is_assignable_to(self, db: &'db dyn Db, other: Self) -> bool {
-        self.class.is_assignable_to(db, other.class)
-    }
-
-    pub(super) fn is_disjoint_from(self, db: &'db dyn Db, other: Self) -> bool {
-        if self.class.is_final(db) && !self.class.is_subclass_of(db, other.class) {
-            return true;
-        }
-
-        if other.class.is_final(db) && !other.class.is_subclass_of(db, self.class) {
-            return true;
-        }
-
-        // Check to see whether the metaclasses of `self` and `other` are disjoint.
-        // Avoid this check if the metaclass of either `self` or `other` is `type`,
-        // however, since we end up with infinite recursion in that case due to the fact
-        // that `type` is its own metaclass (and we know that `type` cannot be disjoint
-        // from any metaclass, anyway).
-        let type_type = KnownClass::Type.to_instance(db);
-        let self_metaclass = self.class.metaclass_instance_type(db);
-        if self_metaclass == type_type {
-            return false;
-        }
-        let other_metaclass = other.class.metaclass_instance_type(db);
-        if other_metaclass == type_type {
-            return false;
-        }
-        self_metaclass.is_disjoint_from(db, other_metaclass)
-    }
-
-    pub(super) fn is_gradual_equivalent_to(self, db: &'db dyn Db, other: Self) -> bool {
-        self.class.is_gradual_equivalent_to(db, other.class)
-    }
-
-    pub(super) fn is_singleton(self, db: &'db dyn Db) -> bool {
-        self.class.known(db).is_some_and(KnownClass::is_singleton)
-    }
-
-    pub(super) fn is_single_valued(self, db: &'db dyn Db) -> bool {
-        self.class
-            .known(db)
-            .is_some_and(KnownClass::is_single_valued)
-    }
-
-    pub(super) fn to_meta_type(self, db: &'db dyn Db) -> Type<'db> {
-        SubclassOfType::from(db, self.class)
-    }
-}
-
-impl<'db> From<InstanceType<'db>> for Type<'db> {
-    fn from(value: InstanceType<'db>) -> Self {
-        Self::Instance(value)
-    }
-}

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 @@
-f65bdc1acde54fda93c802459280da74518d2eef

crates/ruff/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "ruff"
-version = "0.11.7"
+version = "0.11.9"
 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 }
@@ -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

@@ -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,
@@ -1261,12 +1265,12 @@ 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

@@ -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,
 }
 
@@ -146,7 +146,7 @@ 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,
@@ -204,7 +204,7 @@ 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.
@@ -439,7 +439,7 @@ impl LintCacheData {
             .map(|msg| {
                 // Make sure that all message use the same source file.
                 assert_eq!(
-                    &msg.file,
+                    msg.file,
                     messages.first().unwrap().source_file(),
                     "message uses a different source file"
                 );
@@ -616,7 +616,7 @@ 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 +834,6 @@ 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 +842,6 @@ 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/analyze_graph.rs

@@ -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

@@ -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,
@@ -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<'_>>,

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

@@ -2,10 +2,10 @@ use anyhow::{anyhow, Result};
 
 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

@@ -160,7 +160,7 @@ pub(crate) fn format(
                             }),
                             Err(error) => Err(FormatCommandError::Panic(
                                 Some(resolved_file.path().to_path_buf()),
-                                error,
+                                Box::new(error),
                             )),
                         },
                     )
@@ -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())
             };
 
@@ -635,7 +635,7 @@ impl<'a> FormatResults<'a> {
 pub(crate) enum FormatCommandError {
     Ignore(#[from] ignore::Error),
     Parse(#[from] DisplayParseError),
-    Panic(Option<PathBuf>, PanicError),
+    Panic(Option<PathBuf>, Box<PanicError>),
     Read(Option<PathBuf>, SourceError),
     Format(Option<PathBuf>, FormatModuleError),
     Write(Option<PathBuf>, SourceError),

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/diagnostics.rs

@@ -15,7 +15,7 @@ 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::message::Message;
 use ruff_linter::package::PackageRoot;
 use ruff_linter::pyproject_toml::lint_pyproject_toml;
 use ruff_linter::settings::types::UnsafeFixes;
@@ -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

@@ -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}.");
             }

crates/ruff/src/main.rs

@@ -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

@@ -241,7 +241,6 @@ impl Printer {
         }
 
         if !self.flags.intersects(Flags::SHOW_VIOLATIONS) {
-            #[allow(deprecated)]
             if matches!(
                 self.format,
                 OutputFormat::Full | OutputFormat::Concise | OutputFormat::Grouped

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/lint.rs

@@ -994,6 +994,7 @@ fn value_given_to_table_key_is_not_inline_table_2() {
     - `lint.extend-per-file-ignores`
     - `lint.exclude`
     - `lint.preview`
+    - `lint.typing-extensions`
 
     For more information, try '--help'.
     ");
@@ -1899,6 +1900,40 @@ 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<()> {
@@ -2117,7 +2152,7 @@ requires-python = ">= 3.11"
             .arg("test.py")
             .arg("-")
             .current_dir(project_dir)
-            , @r###"
+            , @r#"
         success: true
         exit_code: 0
         ----- stdout -----
@@ -2207,6 +2242,7 @@ requires-python = ">= 3.11"
         	XXX,
         ]
         linter.typing_modules = []
+        linter.typing_extensions = true
 
         # Linter Plugins
         linter.flake8_annotations.mypy_init_return = false
@@ -2390,7 +2426,7 @@ requires-python = ">= 3.11"
         analyze.include_dependencies = {}
 
         ----- stderr -----
-        "###);
+        "#);
     });
     Ok(())
 }
@@ -2428,7 +2464,7 @@ requires-python = ">= 3.11"
             .arg("test.py")
             .arg("-")
             .current_dir(project_dir)
-            , @r###"
+            , @r#"
         success: true
         exit_code: 0
         ----- stdout -----
@@ -2518,6 +2554,7 @@ requires-python = ">= 3.11"
         	XXX,
         ]
         linter.typing_modules = []
+        linter.typing_extensions = true
 
         # Linter Plugins
         linter.flake8_annotations.mypy_init_return = false
@@ -2701,7 +2738,7 @@ requires-python = ">= 3.11"
         analyze.include_dependencies = {}
 
         ----- stderr -----
-        "###);
+        "#);
     });
     Ok(())
 }
@@ -2790,7 +2827,7 @@ from typing import Union;foo: Union[int, str] = 1
             .args(STDIN_BASE_OPTIONS)
             .arg("test.py")
             .arg("--show-settings")
-            .current_dir(project_dir), @r###"
+            .current_dir(project_dir), @r#"
         success: true
         exit_code: 0
         ----- stdout -----
@@ -2881,6 +2918,7 @@ from typing import Union;foo: Union[int, str] = 1
         	XXX,
         ]
         linter.typing_modules = []
+        linter.typing_extensions = true
 
         # Linter Plugins
         linter.flake8_annotations.mypy_init_return = false
@@ -3064,7 +3102,7 @@ from typing import Union;foo: Union[int, str] = 1
         analyze.include_dependencies = {}
 
         ----- stderr -----
-        "###);
+        "#);
     });
     Ok(())
 }
@@ -3170,7 +3208,7 @@ from typing import Union;foo: Union[int, str] = 1
             .arg("--show-settings")
             .args(["--select","UP007"])
             .arg("foo/test.py")
-            .current_dir(&project_dir), @r###"
+            .current_dir(&project_dir), @r#"
         success: true
         exit_code: 0
         ----- stdout -----
@@ -3260,6 +3298,7 @@ from typing import Union;foo: Union[int, str] = 1
         	XXX,
         ]
         linter.typing_modules = []
+        linter.typing_extensions = true
 
         # Linter Plugins
         linter.flake8_annotations.mypy_init_return = false
@@ -3443,7 +3482,7 @@ from typing import Union;foo: Union[int, str] = 1
         analyze.include_dependencies = {}
 
         ----- stderr -----
-        "###);
+        "#);
     });
     Ok(())
 }
@@ -3475,7 +3514,7 @@ requires-python = ">= 3.11"
         &inner_pyproject,
         r#"
 [tool.ruff]
-target-version = "py310"        
+target-version = "py310"
 "#,
     )?;
 
@@ -3497,7 +3536,7 @@ from typing import Union;foo: Union[int, str] = 1
             .arg("--show-settings")
             .args(["--select","UP007"])
             .arg("foo/test.py")
-            .current_dir(&project_dir), @r###"
+            .current_dir(&project_dir), @r#"
         success: true
         exit_code: 0
         ----- stdout -----
@@ -3587,6 +3626,7 @@ from typing import Union;foo: Union[int, str] = 1
         	XXX,
         ]
         linter.typing_modules = []
+        linter.typing_extensions = true
 
         # Linter Plugins
         linter.flake8_annotations.mypy_init_return = false
@@ -3770,7 +3810,7 @@ from typing import Union;foo: Union[int, str] = 1
         analyze.include_dependencies = {}
 
         ----- stderr -----
-        "###);
+        "#);
     });
     Ok(())
 }
@@ -3823,7 +3863,7 @@ from typing import Union;foo: Union[int, str] = 1
             .args(STDIN_BASE_OPTIONS)
             .arg("--show-settings")
             .arg("foo/test.py")
-            .current_dir(&project_dir), @r###"
+            .current_dir(&project_dir), @r#"
         success: true
         exit_code: 0
         ----- stdout -----
@@ -3890,7 +3930,7 @@ 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
@@ -3914,6 +3954,7 @@ from typing import Union;foo: Union[int, str] = 1
         	XXX,
         ]
         linter.typing_modules = []
+        linter.typing_extensions = true
 
         # Linter Plugins
         linter.flake8_annotations.mypy_init_return = false
@@ -4097,7 +4138,7 @@ from typing import Union;foo: Union[int, str] = 1
         analyze.include_dependencies = {}
 
         ----- stderr -----
-        "###);
+        "#);
     });
 
     insta::with_settings!({
@@ -4107,7 +4148,7 @@ from typing import Union;foo: Union[int, str] = 1
             .args(STDIN_BASE_OPTIONS)
             .arg("--show-settings")
             .arg("test.py")
-            .current_dir(project_dir.join("foo")), @r###"
+            .current_dir(project_dir.join("foo")), @r#"
         success: true
         exit_code: 0
         ----- stdout -----
@@ -4174,7 +4215,7 @@ 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
@@ -4198,6 +4239,7 @@ from typing import Union;foo: Union[int, str] = 1
         	XXX,
         ]
         linter.typing_modules = []
+        linter.typing_extensions = true
 
         # Linter Plugins
         linter.flake8_annotations.mypy_init_return = false
@@ -4381,7 +4423,7 @@ from typing import Union;foo: Union[int, str] = 1
         analyze.include_dependencies = {}
 
         ----- stderr -----
-        "###);
+        "#);
     });
     Ok(())
 }
@@ -4444,7 +4486,7 @@ from typing import Union;foo: Union[int, str] = 1
             .args(STDIN_BASE_OPTIONS)
             .arg("--show-settings")
             .arg("test.py")
-            .current_dir(&project_dir), @r###"
+            .current_dir(&project_dir), @r#"
         success: true
         exit_code: 0
         ----- stdout -----
@@ -4535,6 +4577,7 @@ from typing import Union;foo: Union[int, str] = 1
         	XXX,
         ]
         linter.typing_modules = []
+        linter.typing_extensions = true
 
         # Linter Plugins
         linter.flake8_annotations.mypy_init_return = false
@@ -4718,7 +4761,7 @@ from typing import Union;foo: Union[int, str] = 1
         analyze.include_dependencies = {}
 
         ----- stderr -----
-        "###);
+        "#);
     });
 
     Ok(())
@@ -4980,6 +5023,53 @@ fn flake8_import_convention_unused_aliased_import_no_conflict() {
         .pass_stdin("1"));
 }
 
+// See: https://github.com/astral-sh/ruff/issues/16177
+#[test]
+fn flake8_pyi_redundant_none_literal() {
+    let snippet = r#"
+from typing import Literal
+
+# For each of these expressions, Ruff provides a fix for one of the `Literal[None]` elements
+# but not both, as if both were autofixed it would result in `None | None`,
+# which leads to a `TypeError` at runtime.
+a: Literal[None,] | Literal[None,]
+b: Literal[None] | Literal[None]
+c: Literal[None] | Literal[None,]
+d: Literal[None,] | Literal[None]
+"#;
+
+    assert_cmd_snapshot!(Command::new(get_cargo_bin(BIN_NAME))
+        .args(STDIN_BASE_OPTIONS)
+        .args(["--select", "PYI061"])
+        .args(["--stdin-filename", "test.py"])
+        .arg("--preview")
+        .arg("--diff")
+        .arg("-")
+        .pass_stdin(snippet), @r"
+    success: false
+    exit_code: 1
+    ----- stdout -----
+    --- test.py
+    +++ test.py
+    @@ -4,7 +4,7 @@
+     # For each of these expressions, Ruff provides a fix for one of the `Literal[None]` elements
+     # but not both, as if both were autofixed it would result in `None | None`,
+     # which leads to a `TypeError` at runtime.
+    -a: Literal[None,] | Literal[None,]
+    -b: Literal[None] | Literal[None]
+    -c: Literal[None] | Literal[None,]
+    -d: Literal[None,] | Literal[None]
+    +a: None | Literal[None,]
+    +b: None | Literal[None]
+    +c: None | Literal[None,]
+    +d: None | Literal[None]
+
+
+    ----- stderr -----
+    Would fix 4 errors.
+    ");
+}
+
 /// Test that private, old-style `TypeVar` generics
 /// 1. Get replaced with PEP 695 type parameters (UP046, UP047)
 /// 2. Get renamed to remove leading underscores (UP049)
@@ -5564,3 +5654,34 @@ 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/tests/snapshots/show_settings__display_default_settings.snap

@@ -213,6 +213,7 @@ linter.task_tags = [
 	XXX,
 ]
 linter.typing_modules = []
+linter.typing_extensions = true
 
 # Linter Plugins
 linter.flake8_annotations.mypy_init_return = false

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/linter.rs

@@ -45,9 +45,9 @@ static GLOBAL: tikv_jemallocator::Jemalloc = tikv_jemallocator::Jemalloc;
         target_arch = "powerpc64"
     )
 ))]
-#[allow(non_upper_case_globals)]
+#[expect(non_upper_case_globals)]
 #[export_name = "_rjem_malloc_conf"]
-#[allow(unsafe_code)]
+#[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/ty.rs

@@ -7,16 +7,16 @@ use criterion::{criterion_group, criterion_main, BatchSize, Criterion};
 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::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 +59,40 @@ 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,
-)];
+// left: [
+// (Lint(LintName("invalid-argument-type")), Some("/src/tomllib/_parser.py"), Some(8224..8254), "Argument to function `skip_until` is incorrect", Error),
+// (Lint(LintName("invalid-argument-type")), Some("/src/tomllib/_parser.py"), Some(16914..16948), "Argument to function `skip_until` is incorrect", Error),
+// (Lint(LintName("invalid-argument-type")), Some("/src/tomllib/_parser.py"), Some(17319..17363), "Argument to function `skip_until` is incorrect", Error),
+// ]
+//right: [
+// (Lint(LintName("invalid-argument-type")), Some("/src/tomllib/_parser.py"), Some(8224..8254), "Argument to this function is incorrect", Error),
+// (Lint(LintName("invalid-argument-type")), Some("/src/tomllib/_parser.py"), Some(16914..16948), "Argument to this function is incorrect", Error),
+// (Lint(LintName("invalid-argument-type")), Some("/src/tomllib/_parser.py"), Some(17319..17363), "Argument to this function is incorrect", Error),
+// ]
+
+static EXPECTED_TOMLLIB_DIAGNOSTICS: &[KeyDiagnosticFields] = &[
+    (
+        DiagnosticId::lint("invalid-argument-type"),
+        Some("/src/tomllib/_parser.py"),
+        Some(8224..8254),
+        "Argument to function `skip_until` is incorrect",
+        Severity::Error,
+    ),
+    (
+        DiagnosticId::lint("invalid-argument-type"),
+        Some("/src/tomllib/_parser.py"),
+        Some(16914..16948),
+        "Argument to function `skip_until` is incorrect",
+        Severity::Error,
+    ),
+    (
+        DiagnosticId::lint("invalid-argument-type"),
+        Some("/src/tomllib/_parser.py"),
+        Some(17319..17363),
+        "Argument to function `skip_until` is incorrect",
+        Severity::Error,
+    ),
+];
 
 fn tomllib_path(file: &TestFile) -> SystemPathBuf {
     SystemPathBuf::from("src").join(file.name())
@@ -122,7 +149,7 @@ 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 +199,7 @@ 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 +207,7 @@ 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 +230,7 @@ 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 +284,7 @@ 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

crates/ruff_cache/src/cache_key.rs

@@ -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

@@ -20,6 +20,7 @@ ruff_python_trivia = { workspace = true }
 ruff_source_file = { workspace = true }
 ruff_text_size = { workspace = true }
 
+anstyle = { workspace = true }
 camino = { workspace = true }
 countme = { workspace = true }
 dashmap = { workspace = true }

crates/ruff_db/src/diagnostic/mod.rs

@@ -1,16 +1,16 @@
 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::{files::File, Db};
 
-use self::render::FileResolver;
 mod render;
+mod stylesheet;
 
 /// A collection of information that can be rendered into a diagnostic.
 ///
@@ -114,10 +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)
     }
 
@@ -133,20 +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())
@@ -164,7 +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
@@ -226,6 +225,30 @@ 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,
+        }
+    }
 }
 
 #[derive(Debug, Clone, Eq, PartialEq)]
@@ -237,6 +260,60 @@ 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
@@ -337,6 +414,8 @@ 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 {
@@ -354,6 +433,7 @@ impl Annotation {
             span,
             message: None,
             is_primary: true,
+            tags: Vec::new(),
         }
     }
 
@@ -369,6 +449,7 @@ impl Annotation {
             span,
             message: None,
             is_primary: false,
+            tags: Vec::new(),
         }
     }
 
@@ -411,6 +492,36 @@ impl Annotation {
     pub fn get_span(&self) -> &Span {
         &self.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.
@@ -501,62 +612,84 @@ 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) -> &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()),
         }
     }
 }
@@ -568,14 +701,14 @@ 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`.
@@ -596,10 +729,38 @@ 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 }
     }
 }
@@ -634,6 +795,10 @@ 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/stylesheet.rs

@@ -0,0 +1,80 @@
+use anstyle::{AnsiColor, Effects, Style};
+use std::fmt::Formatter;
+
+pub(super) const fn fmt_styled<'a, T>(
+    content: T,
+    style: anstyle::Style,
+) -> impl std::fmt::Display + 'a
+where
+    T: std::fmt::Display + 'a,
+{
+    struct FmtStyled<T> {
+        content: T,
+        style: anstyle::Style,
+    }
+
+    impl<T> std::fmt::Display for FmtStyled<T>
+    where
+        T: std::fmt::Display,
+    {
+        fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
+            write!(
+                f,
+                "{style_start}{content}{style_end}",
+                style_start = self.style.render(),
+                content = self.content,
+                style_end = self.style.render_reset()
+            )
+        }
+    }
+
+    FmtStyled { content, style }
+}
+
+#[derive(Clone, Debug)]
+pub struct DiagnosticStylesheet {
+    pub(crate) error: Style,
+    pub(crate) warning: Style,
+    pub(crate) info: Style,
+    pub(crate) note: Style,
+    pub(crate) help: Style,
+    pub(crate) line_no: Style,
+    pub(crate) emphasis: Style,
+    pub(crate) none: Style,
+}
+
+impl Default for DiagnosticStylesheet {
+    fn default() -> Self {
+        Self::plain()
+    }
+}
+
+impl DiagnosticStylesheet {
+    /// Default terminal styling
+    pub fn styled() -> Self {
+        let bright_blue = AnsiColor::BrightBlue.on_default();
+        Self {
+            error: AnsiColor::BrightRed.on_default().effects(Effects::BOLD),
+            warning: AnsiColor::Yellow.on_default().effects(Effects::BOLD),
+            info: bright_blue.effects(Effects::BOLD),
+            note: AnsiColor::BrightGreen.on_default().effects(Effects::BOLD),
+            help: AnsiColor::BrightCyan.on_default().effects(Effects::BOLD),
+            line_no: bright_blue.effects(Effects::BOLD),
+            emphasis: Style::new().effects(Effects::BOLD),
+            none: Style::new(),
+        }
+    }
+
+    pub fn plain() -> Self {
+        Self {
+            error: Style::new(),
+            warning: Style::new(),
+            info: Style::new(),
+            note: Style::new(),
+            help: Style::new(),
+            line_no: Style::new(),
+            emphasis: Style::new(),
+            none: Style::new(),
+        }
+    }
+}

crates/ruff_db/src/files.rs

@@ -94,7 +94,9 @@ impl Files {
                     .root(db, path)
                     .map_or(Durability::default(), |root| root.durability(db));
 
-                let builder = File::builder(FilePath::System(absolute)).durability(durability);
+                let builder = File::builder(FilePath::System(absolute))
+                    .durability(durability)
+                    .path_durability(Durability::HIGH);
 
                 let builder = match metadata {
                     Ok(metadata) if metadata.file_type().is_file() => builder
@@ -159,9 +161,11 @@ impl Files {
         tracing::trace!("Adding virtual file {}", path);
         let virtual_file = VirtualFile(
             File::builder(FilePath::SystemVirtual(path.to_path_buf()))
+                .path_durability(Durability::HIGH)
                 .status(FileStatus::Exists)
                 .revision(FileRevision::zero())
                 .permissions(None)
+                .permissions_durability(Durability::HIGH)
                 .new(db),
         );
         self.inner
@@ -272,8 +276,8 @@ 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.
 #[salsa::input]
 pub struct File {
-    /// The path of the file.
-    #[return_ref]
+    /// The path of the file (immutable).
+    #[returns(ref)]
     pub path: FilePath,
 
     /// The unix permissions of the file. Only supported on unix systems. Always `None` on Windows

crates/ruff_db/src/files/file_root.rs

@@ -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/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/panic.rs

@@ -1,12 +1,29 @@
+use std::backtrace::BacktraceStatus;
 use std::cell::Cell;
 use std::panic::Location;
 use std::sync::OnceLock;
 
-#[derive(Default, Debug)]
+#[derive(Debug)]
 pub struct PanicError {
     pub location: Option<String>,
-    pub payload: Option<String>,
+    pub payload: Payload,
     pub backtrace: Option<std::backtrace::Backtrace>,
+    pub salsa_backtrace: Option<salsa::Backtrace>,
+}
+
+#[derive(Debug)]
+pub struct Payload(Box<dyn std::any::Any + Send>);
+
+impl Payload {
+    pub fn as_str(&self) -> Option<&str> {
+        if let Some(s) = self.0.downcast_ref::<String>() {
+            Some(s)
+        } else if let Some(s) = self.0.downcast_ref::<&str>() {
+            Some(s)
+        } else {
+            None
+        }
+    }
 }
 
 impl std::fmt::Display for PanicError {
@@ -15,20 +32,39 @@ impl std::fmt::Display for PanicError {
         if let Some(location) = &self.location {
             write!(f, " {location}")?;
         }
-        if let Some(payload) = &self.payload {
+        if let Some(payload) = self.payload.as_str() {
             write!(f, ":\n{payload}")?;
         }
         if let Some(backtrace) = &self.backtrace {
-            writeln!(f, "\nBacktrace: {backtrace}")?;
+            match backtrace.status() {
+                BacktraceStatus::Disabled => {
+                    writeln!(
+                        f,
+                        "\nrun with `RUST_BACKTRACE=1` environment variable to display a backtrace"
+                    )?;
+                }
+                BacktraceStatus::Captured => {
+                    writeln!(f, "\nBacktrace: {backtrace}")?;
+                }
+                _ => {}
+            }
         }
         Ok(())
     }
 }
 
+#[derive(Default)]
+struct CapturedPanicInfo {
+    backtrace: Option<std::backtrace::Backtrace>,
+    location: Option<String>,
+    salsa_backtrace: Option<salsa::Backtrace>,
+}
+
 thread_local! {
     static CAPTURE_PANIC_INFO: Cell<bool> = const { Cell::new(false) };
-    static OUR_HOOK_RAN: Cell<bool> = const { Cell::new(false) };
-    static LAST_PANIC: Cell<Option<PanicError>> = const { Cell::new(None) };
+    static LAST_BACKTRACE: Cell<CapturedPanicInfo> = const {
+        Cell::new(CapturedPanicInfo { backtrace: None, location: None, salsa_backtrace: None })
+    };
 }
 
 fn install_hook() {
@@ -36,24 +72,18 @@ fn install_hook() {
     ONCE.get_or_init(|| {
         let prev = std::panic::take_hook();
         std::panic::set_hook(Box::new(move |info| {
-            OUR_HOOK_RAN.with(|cell| cell.set(true));
             let should_capture = CAPTURE_PANIC_INFO.with(Cell::get);
             if !should_capture {
                 return (*prev)(info);
             }
-            let payload = if let Some(s) = info.payload().downcast_ref::<&str>() {
-                Some(s.to_string())
-            } else {
-                info.payload().downcast_ref::<String>().cloned()
-            };
+
             let location = info.location().map(Location::to_string);
-            let backtrace = std::backtrace::Backtrace::force_capture();
-            LAST_PANIC.with(|cell| {
-                cell.set(Some(PanicError {
-                    payload,
-                    location,
-                    backtrace: Some(backtrace),
-                }));
+            let backtrace = Some(std::backtrace::Backtrace::capture());
+
+            LAST_BACKTRACE.set(CapturedPanicInfo {
+                backtrace,
+                location,
+                salsa_backtrace: salsa::Backtrace::capture(),
             });
         }));
     });
@@ -70,7 +100,7 @@ fn install_hook() {
 /// stderr).
 ///
 /// We assume that there is nothing else running in this process that needs to install a competing
-/// panic hook.  We are careful to install our custom hook only once, and we do not ever restore
+/// panic hook. We are careful to install our custom hook only once, and we do not ever restore
 /// the previous hook (since you can always retain the previous hook's behavior by not calling this
 /// wrapper).
 pub fn catch_unwind<F, R>(f: F) -> Result<R, PanicError>
@@ -78,15 +108,83 @@ where
     F: FnOnce() -> R + std::panic::UnwindSafe,
 {
     install_hook();
-    OUR_HOOK_RAN.with(|cell| cell.set(false));
-    let prev_should_capture = CAPTURE_PANIC_INFO.with(|cell| cell.replace(true));
-    let result = std::panic::catch_unwind(f).map_err(|_| {
-        let our_hook_ran = OUR_HOOK_RAN.with(Cell::get);
-        if !our_hook_ran {
-            panic!("detected a competing panic hook");
+    let prev_should_capture = CAPTURE_PANIC_INFO.replace(true);
+    let result = std::panic::catch_unwind(f).map_err(|payload| {
+        // Try to get the backtrace and location from our custom panic hook.
+        // The custom panic hook only runs once when `panic!` is called (or similar). It doesn't
+        // run when the panic is propagated with `std::panic::resume_unwind`. The panic hook
+        // is also not called when the panic is raised with `std::panic::resum_unwind` as is the
+        // case for salsa unwinds (see the ignored test below).
+        // Because of that, always take the payload from `catch_unwind` because it may have been transformed
+        // by an inner `std::panic::catch_unwind` handlers and only use the information
+        // from the custom handler to enrich the error with the backtrace and location.
+        let CapturedPanicInfo {
+            location,
+            backtrace,
+            salsa_backtrace,
+        } = LAST_BACKTRACE.with(Cell::take);
+
+        PanicError {
+            location,
+            payload: Payload(payload),
+            backtrace,
+            salsa_backtrace,
         }
-        LAST_PANIC.with(Cell::take).unwrap_or_default()
     });
-    CAPTURE_PANIC_INFO.with(|cell| cell.set(prev_should_capture));
+    CAPTURE_PANIC_INFO.set(prev_should_capture);
     result
 }
+
+#[cfg(test)]
+mod tests {
+    use salsa::{Database, Durability};
+
+    #[test]
+    #[ignore = "super::catch_unwind installs a custom panic handler, which could effect test isolation"]
+    fn no_backtrace_for_salsa_cancelled() {
+        #[salsa::input]
+        struct Input {
+            value: u32,
+        }
+
+        #[salsa::tracked]
+        fn test_query(db: &dyn Database, input: Input) -> u32 {
+            loop {
+                // This should throw a cancelled error
+                let _ = input.value(db);
+            }
+        }
+
+        let db = salsa::DatabaseImpl::new();
+
+        let input = Input::new(&db, 42);
+
+        let result = std::thread::scope(move |scope| {
+            {
+                let mut db = db.clone();
+                scope.spawn(move || {
+                    // This will cancel the other thread by throwing a `salsa::Cancelled` error.
+                    db.synthetic_write(Durability::MEDIUM);
+                });
+            }
+
+            {
+                scope.spawn(move || {
+                    super::catch_unwind(|| {
+                        test_query(&db, input);
+                    })
+                })
+            }
+            .join()
+            .unwrap()
+        });
+
+        match result {
+            Ok(_) => panic!("Expected query to panic"),
+            Err(err) => {
+                // Panics triggered with `resume_unwind` have no backtrace.
+                assert!(err.backtrace.is_none());
+            }
+        }
+    }
+}

crates/ruff_db/src/parsed.rs

@@ -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();
 

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,
@@ -427,11 +426,7 @@ 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();

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

crates/ruff_db/src/testing.rs

@@ -107,7 +107,7 @@ fn query_name<Q>(_query: &Q) -> &'static str {
         .unwrap_or(full_qualified_query_name)
 }
 
-/// Sets up logging for the current thread. It captures all `red_knot` and `ruff` events.
+/// Sets up logging for the current thread. It captures all `ty` and `ruff` events.
 ///
 /// Useful for capturing the tracing output in a failing test.
 ///
@@ -128,7 +128,7 @@ pub fn setup_logging() -> LoggingGuard {
 /// # Examples
 /// ```
 /// use ruff_db::testing::setup_logging_with_filter;
-/// let _logging = setup_logging_with_filter("red_knot_module_resolver::resolver");
+/// let _logging = setup_logging_with_filter("ty_module_resolver::resolver");
 /// ```
 ///
 /// # Filter
@@ -148,11 +148,7 @@ impl LoggingBuilder {
     pub fn new() -> Self {
         Self {
             filter: EnvFilter::default()
-                .add_directive(
-                    "red_knot=trace"
-                        .parse()
-                        .expect("Hardcoded directive to be valid"),
-                )
+                .add_directive("ty=trace".parse().expect("Hardcoded directive to be valid"))
                 .add_directive(
                     "ruff=trace"
                         .parse()

crates/ruff_db/src/vendored.rs

@@ -172,7 +172,7 @@ impl Default for VendoredFileSystem {
 /// that users of the `VendoredFileSystem` could realistically need.
 /// For debugging purposes, however, we want to have all information
 /// available.
-#[allow(unused)]
+#[expect(unused)]
 #[derive(Debug)]
 struct ZipFileDebugInfo {
     crc32_hash: u32,

crates/ruff_dev/Cargo.toml

@@ -11,12 +11,14 @@ repository = { workspace = true }
 license = { workspace = true }
 
 [dependencies]
-red_knot_project = { workspace = true, features = ["schemars"] }
+ty = { workspace = true }
+ty_project = { workspace = true, features = ["schemars"] }
 ruff = { workspace = true }
 ruff_diagnostics = { workspace = true }
 ruff_formatter = { workspace = true }
 ruff_linter = { workspace = true, features = ["schemars"] }
 ruff_notebook = { workspace = true }
+ruff_options_metadata = { workspace = true }
 ruff_python_ast = { workspace = true }
 ruff_python_codegen = { workspace = true }
 ruff_python_formatter = { workspace = true }
@@ -31,6 +33,7 @@ imara-diff = { workspace = true }
 indicatif = { workspace = true }
 itertools = { workspace = true }
 libcst = { workspace = true }
+markdown = { version = "1.0.0" }
 pretty_assertions = { workspace = true }
 rayon = { workspace = true }
 regex = { workspace = true }
@@ -44,6 +47,7 @@ toml = { workspace = true, features = ["parse"] }
 tracing = { workspace = true }
 tracing-indicatif = { workspace = true }
 tracing-subscriber = { workspace = true, features = ["env-filter"] }
+url = { workspace = true }
 
 [dev-dependencies]
 indoc = { workspace = true }

crates/ruff_dev/src/format_dev.rs

@@ -63,7 +63,6 @@ fn find_pyproject_config(
 }
 
 /// Find files that ruff would check so we can format them. Adapted from `ruff`.
-#[allow(clippy::type_complexity)]
 fn ruff_check_paths<'a>(
     pyproject_config: &'a PyprojectConfig,
     cli: &FormatArguments,
@@ -135,12 +134,12 @@ impl Statistics {
     }
 
     /// We currently prefer the similarity index, but i'd like to keep this around
-    #[allow(clippy::cast_precision_loss, unused)]
+    #[expect(clippy::cast_precision_loss, unused)]
     pub(crate) fn jaccard_index(&self) -> f32 {
         self.intersection as f32 / (self.black_input + self.ruff_output + self.intersection) as f32
     }
 
-    #[allow(clippy::cast_precision_loss)]
+    #[expect(clippy::cast_precision_loss)]
     pub(crate) fn similarity_index(&self) -> f32 {
         self.intersection as f32 / (self.black_input + self.intersection) as f32
     }
@@ -177,7 +176,7 @@ pub(crate) enum Format {
     Full,
 }
 
-#[allow(clippy::struct_excessive_bools)]
+#[expect(clippy::struct_excessive_bools)]
 #[derive(clap::Args)]
 pub(crate) struct Args {
     /// Like `ruff check`'s files. See `--multi-project` if you want to format an ecosystem
@@ -222,7 +221,7 @@ pub(crate) struct Args {
     #[arg(long)]
     pub(crate) files_with_errors: Option<u32>,
     #[clap(flatten)]
-    #[allow(clippy::struct_field_names)]
+    #[expect(clippy::struct_field_names)]
     pub(crate) log_level_args: LogLevelArgs,
 }
 

crates/ruff_dev/src/generate_all.rs

@@ -2,7 +2,10 @@
 
 use anyhow::Result;
 
-use crate::{generate_cli_help, generate_docs, generate_json_schema, generate_knot_schema};
+use crate::{
+    generate_cli_help, generate_docs, generate_json_schema, generate_ty_cli_reference,
+    generate_ty_options, generate_ty_rules, generate_ty_schema,
+};
 
 pub(crate) const REGENERATE_ALL_COMMAND: &str = "cargo dev generate-all";
 
@@ -33,10 +36,13 @@ impl Mode {
 
 pub(crate) fn main(args: &Args) -> Result<()> {
     generate_json_schema::main(&generate_json_schema::Args { mode: args.mode })?;
-    generate_knot_schema::main(&generate_knot_schema::Args { mode: args.mode })?;
+    generate_ty_schema::main(&generate_ty_schema::Args { mode: args.mode })?;
     generate_cli_help::main(&generate_cli_help::Args { mode: args.mode })?;
     generate_docs::main(&generate_docs::Args {
         dry_run: args.mode.is_dry_run(),
     })?;
+    generate_ty_options::main(&generate_ty_options::Args { mode: args.mode })?;
+    generate_ty_rules::main(&generate_ty_rules::Args { mode: args.mode })?;
+    generate_ty_cli_reference::main(&generate_ty_cli_reference::Args { mode: args.mode })?;
     Ok(())
 }

crates/ruff_dev/src/generate_cli_help.rs

@@ -1,5 +1,4 @@
 //! Generate CLI help.
-#![allow(clippy::print_stdout)]
 
 use std::path::PathBuf;
 use std::{fs, str};

crates/ruff_dev/src/generate_docs.rs

@@ -1,5 +1,4 @@
 //! Generate Markdown documentation for applicable rules.
-#![allow(clippy::print_stdout, clippy::print_stderr)]
 
 use std::collections::HashSet;
 use std::fmt::Write as _;
@@ -13,8 +12,8 @@ use strum::IntoEnumIterator;
 
 use ruff_diagnostics::FixAvailability;
 use ruff_linter::registry::{Linter, Rule, RuleNamespace};
+use ruff_options_metadata::{OptionEntry, OptionsMetadata};
 use ruff_workspace::options::Options;
-use ruff_workspace::options_base::{OptionEntry, OptionsMetadata};
 
 use crate::ROOT_DIR;
 

crates/ruff_dev/src/generate_json_schema.rs

@@ -1,5 +1,3 @@
-#![allow(clippy::print_stdout, clippy::print_stderr)]
-
 use std::fs;
 use std::path::PathBuf;
 

crates/ruff_dev/src/generate_options.rs

@@ -4,9 +4,9 @@
 use itertools::Itertools;
 use std::fmt::Write;
 
+use ruff_options_metadata::{OptionField, OptionSet, OptionsMetadata, Visit};
 use ruff_python_trivia::textwrap;
 use ruff_workspace::options::Options;
-use ruff_workspace::options_base::{OptionField, OptionSet, OptionsMetadata, Visit};
 
 pub(crate) fn generate() -> String {
     let mut output = String::new();

crates/ruff_dev/src/generate_rules_table.rs

@@ -11,8 +11,8 @@ use strum::IntoEnumIterator;
 use ruff_diagnostics::FixAvailability;
 use ruff_linter::registry::{Linter, Rule, RuleNamespace};
 use ruff_linter::upstream_categories::UpstreamCategoryAndPrefix;
+use ruff_options_metadata::OptionsMetadata;
 use ruff_workspace::options::Options;
-use ruff_workspace::options_base::OptionsMetadata;
 
 const FIX_SYMBOL: &str = "🛠️";
 const PREVIEW_SYMBOL: &str = "🧪";
@@ -34,7 +34,6 @@ fn generate_table(table_out: &mut String, rules: impl IntoIterator<Item = Rule>,
             RuleGroup::Deprecated => {
                 format!("<span title='Rule has been deprecated'>{WARNING_SYMBOL}</span>")
             }
-            #[allow(deprecated)]
             RuleGroup::Preview => {
                 format!("<span title='Rule is in preview'>{PREVIEW_SYMBOL}</span>")
             }
@@ -78,7 +77,7 @@ fn generate_table(table_out: &mut String, rules: impl IntoIterator<Item = Rule>,
             se = "</span>";
         }
 
-        #[allow(clippy::or_fun_call)]
+        #[expect(clippy::or_fun_call)]
         let _ = write!(
             table_out,
             "| {ss}{0}{1}{se} {{ #{0}{1} }} | {ss}{2}{se} | {ss}{3}{se} | {ss}{4}{se} |",

crates/ruff_dev/src/generate_ty_cli_reference.rs

@@ -0,0 +1,334 @@
+//! Generate a Markdown-compatible reference for the ty command-line interface.
+use std::cmp::max;
+use std::path::PathBuf;
+
+use anyhow::{bail, Result};
+use clap::{Command, CommandFactory};
+use itertools::Itertools;
+use pretty_assertions::StrComparison;
+
+use crate::generate_all::{Mode, REGENERATE_ALL_COMMAND};
+use crate::ROOT_DIR;
+
+use ty::Cli;
+
+const SHOW_HIDDEN_COMMANDS: &[&str] = &["generate-shell-completion"];
+
+#[derive(clap::Args)]
+pub(crate) struct Args {
+    #[arg(long, default_value_t, value_enum)]
+    pub(crate) mode: Mode,
+}
+
+pub(crate) fn main(args: &Args) -> Result<()> {
+    let reference_string = generate();
+    let filename = "crates/ty/docs/cli.md";
+    let reference_path = PathBuf::from(ROOT_DIR).join(filename);
+
+    match args.mode {
+        Mode::DryRun => {
+            println!("{reference_string}");
+        }
+        Mode::Check => {
+            match std::fs::read_to_string(reference_path) {
+                Ok(current) => {
+                    if current == reference_string {
+                        println!("Up-to-date: {filename}");
+                    } else {
+                        let comparison = StrComparison::new(&current, &reference_string);
+                        bail!("{filename} changed, please run `{REGENERATE_ALL_COMMAND}`:\n{comparison}");
+                    }
+                }
+                Err(err) if err.kind() == std::io::ErrorKind::NotFound => {
+                    bail!("{filename} not found, please run `{REGENERATE_ALL_COMMAND}`");
+                }
+                Err(err) => {
+                    bail!("{filename} changed, please run `{REGENERATE_ALL_COMMAND}`:\n{err}");
+                }
+            }
+        }
+        Mode::Write => match std::fs::read_to_string(&reference_path) {
+            Ok(current) => {
+                if current == reference_string {
+                    println!("Up-to-date: {filename}");
+                } else {
+                    println!("Updating: {filename}");
+                    std::fs::write(reference_path, reference_string.as_bytes())?;
+                }
+            }
+            Err(err) if err.kind() == std::io::ErrorKind::NotFound => {
+                println!("Updating: {filename}");
+                std::fs::write(reference_path, reference_string.as_bytes())?;
+            }
+            Err(err) => {
+                bail!("{filename} changed, please run `cargo dev generate-cli-reference`:\n{err}");
+            }
+        },
+    }
+
+    Ok(())
+}
+
+fn generate() -> String {
+    let mut output = String::new();
+
+    let mut ty = Cli::command();
+
+    // It is very important to build the command before beginning inspection or subcommands
+    // will be missing all of the propagated options.
+    ty.build();
+
+    let mut parents = Vec::new();
+
+    output.push_str("# CLI Reference\n\n");
+    generate_command(&mut output, &ty, &mut parents);
+
+    output
+}
+
+#[allow(clippy::format_push_string)]
+fn generate_command<'a>(output: &mut String, command: &'a Command, parents: &mut Vec<&'a Command>) {
+    if command.is_hide_set() && !SHOW_HIDDEN_COMMANDS.contains(&command.get_name()) {
+        return;
+    }
+
+    // Generate the command header.
+    let name = if parents.is_empty() {
+        command.get_name().to_string()
+    } else {
+        format!(
+            "{} {}",
+            parents.iter().map(|cmd| cmd.get_name()).join(" "),
+            command.get_name()
+        )
+    };
+
+    // Display the top-level `ty` command at the same level as its children
+    let level = max(2, parents.len() + 1);
+    output.push_str(&format!("{} {name}\n\n", "#".repeat(level)));
+
+    // Display the command description.
+    if let Some(about) = command.get_long_about().or_else(|| command.get_about()) {
+        output.push_str(&about.to_string());
+        output.push_str("\n\n");
+    }
+
+    // Display the usage
+    {
+        // This appears to be the simplest way to get rendered usage from Clap,
+        // it is complicated to render it manually. It's annoying that it
+        // requires a mutable reference but it doesn't really matter.
+        let mut command = command.clone();
+        output.push_str("<h3 class=\"cli-reference\">Usage</h3>\n\n");
+        output.push_str(&format!(
+            "```\n{}\n```",
+            command
+                .render_usage()
+                .to_string()
+                .trim_start_matches("Usage: "),
+        ));
+        output.push_str("\n\n");
+    }
+
+    if command.get_name() == "help" {
+        return;
+    }
+
+    // Display a list of child commands
+    let mut subcommands = command.get_subcommands().peekable();
+    let has_subcommands = subcommands.peek().is_some();
+    if has_subcommands {
+        output.push_str("<h3 class=\"cli-reference\">Commands</h3>\n\n");
+        output.push_str("<dl class=\"cli-reference\">");
+
+        for subcommand in subcommands {
+            if subcommand.is_hide_set() {
+                continue;
+            }
+            let subcommand_name = format!("{name} {}", subcommand.get_name());
+            output.push_str(&format!(
+                "<dt><a href=\"#{}\"><code>{subcommand_name}</code></a></dt>",
+                subcommand_name.replace(' ', "-")
+            ));
+            if let Some(about) = subcommand.get_about() {
+                output.push_str(&format!(
+                    "<dd>{}</dd>\n",
+                    markdown::to_html(&about.to_string())
+                ));
+            }
+        }
+
+        output.push_str("</dl>\n\n");
+    }
+
+    // Do not display options for commands with children
+    if !has_subcommands {
+        let name_key = name.replace(' ', "-");
+
+        // Display positional arguments
+        let mut arguments = command
+            .get_positionals()
+            .filter(|arg| !arg.is_hide_set())
+            .peekable();
+
+        if arguments.peek().is_some() {
+            output.push_str("<h3 class=\"cli-reference\">Arguments</h3>\n\n");
+            output.push_str("<dl class=\"cli-reference\">");
+
+            for arg in arguments {
+                let id = format!("{name_key}--{}", arg.get_id());
+                output.push_str(&format!("<dt id=\"{id}\">"));
+                output.push_str(&format!(
+                    "<a href=\"#{id}\"<code>{}</code></a>",
+                    arg.get_id().to_string().to_uppercase(),
+                ));
+                output.push_str("</dt>");
+                if let Some(help) = arg.get_long_help().or_else(|| arg.get_help()) {
+                    output.push_str("<dd>");
+                    output.push_str(&format!("{}\n", markdown::to_html(&help.to_string())));
+                    output.push_str("</dd>");
+                }
+            }
+
+            output.push_str("</dl>\n\n");
+        }
+
+        // Display options and flags
+        let mut options = command
+            .get_arguments()
+            .filter(|arg| !arg.is_positional())
+            .filter(|arg| !arg.is_hide_set())
+            .sorted_by_key(|arg| arg.get_id())
+            .peekable();
+
+        if options.peek().is_some() {
+            output.push_str("<h3 class=\"cli-reference\">Options</h3>\n\n");
+            output.push_str("<dl class=\"cli-reference\">");
+            for opt in options {
+                let Some(long) = opt.get_long() else { continue };
+                let id = format!("{name_key}--{long}");
+
+                output.push_str(&format!("<dt id=\"{id}\">"));
+                output.push_str(&format!("<a href=\"#{id}\"><code>--{long}</code></a>"));
+                for long_alias in opt.get_all_aliases().into_iter().flatten() {
+                    output.push_str(&format!(", <code>--{long_alias}</code>"));
+                }
+                if let Some(short) = opt.get_short() {
+                    output.push_str(&format!(", <code>-{short}</code>"));
+                }
+                for short_alias in opt.get_all_short_aliases().into_iter().flatten() {
+                    output.push_str(&format!(", <code>-{short_alias}</code>"));
+                }
+
+                // Re-implements private `Arg::is_takes_value_set` used in `Command::get_opts`
+                if opt
+                    .get_num_args()
+                    .unwrap_or_else(|| 1.into())
+                    .takes_values()
+                {
+                    if let Some(values) = opt.get_value_names() {
+                        for value in values {
+                            output.push_str(&format!(
+                                " <i>{}</i>",
+                                value.to_lowercase().replace('_', "-")
+                            ));
+                        }
+                    }
+                }
+                output.push_str("</dt>");
+                if let Some(help) = opt.get_long_help().or_else(|| opt.get_help()) {
+                    output.push_str("<dd>");
+                    output.push_str(&format!("{}\n", markdown::to_html(&help.to_string())));
+                    emit_env_option(opt, output);
+                    emit_default_option(opt, output);
+                    emit_possible_options(opt, output);
+                    output.push_str("</dd>");
+                }
+            }
+
+            output.push_str("</dl>");
+        }
+
+        output.push_str("\n\n");
+    }
+
+    parents.push(command);
+
+    // Recurse to all of the subcommands.
+    for subcommand in command.get_subcommands() {
+        generate_command(output, subcommand, parents);
+    }
+
+    parents.pop();
+}
+
+fn emit_env_option(opt: &clap::Arg, output: &mut String) {
+    if opt.is_hide_env_set() {
+        return;
+    }
+    if let Some(env) = opt.get_env() {
+        output.push_str(&markdown::to_html(&format!(
+            "May also be set with the `{}` environment variable.",
+            env.to_string_lossy()
+        )));
+    }
+}
+
+fn emit_default_option(opt: &clap::Arg, output: &mut String) {
+    if opt.is_hide_default_value_set() || !opt.get_num_args().expect("built").takes_values() {
+        return;
+    }
+
+    let values = opt.get_default_values();
+    if !values.is_empty() {
+        let value = format!(
+            "\n[default: {}]",
+            opt.get_default_values()
+                .iter()
+                .map(|s| s.to_string_lossy())
+                .join(",")
+        );
+        output.push_str(&markdown::to_html(&value));
+    }
+}
+
+fn emit_possible_options(opt: &clap::Arg, output: &mut String) {
+    if opt.is_hide_possible_values_set() {
+        return;
+    }
+
+    let values = opt.get_possible_values();
+    if !values.is_empty() {
+        let value = format!(
+            "\nPossible values:\n{}",
+            values
+                .into_iter()
+                .filter(|value| !value.is_hide_set())
+                .map(|value| {
+                    let name = value.get_name();
+                    value.get_help().map_or_else(
+                        || format!(" - `{name}`"),
+                        |help| format!(" - `{name}`:  {help}"),
+                    )
+                })
+                .collect_vec()
+                .join("\n"),
+        );
+        output.push_str(&markdown::to_html(&value));
+    }
+}
+
+#[cfg(test)]
+mod tests {
+
+    use anyhow::Result;
+
+    use crate::generate_all::Mode;
+
+    use super::{main, Args};
+
+    #[test]
+    fn ty_cli_reference_is_up_to_date() -> Result<()> {
+        main(&Args { mode: Mode::Check })
+    }
+}

crates/ruff_dev/src/generate_ty_options.rs

@@ -0,0 +1,257 @@
+//! Generate a Markdown-compatible listing of configuration options for `pyproject.toml`.
+
+use anyhow::bail;
+use itertools::Itertools;
+use pretty_assertions::StrComparison;
+use std::{fmt::Write, path::PathBuf};
+
+use ruff_options_metadata::{OptionField, OptionSet, OptionsMetadata, Visit};
+use ty_project::metadata::Options;
+
+use crate::{
+    generate_all::{Mode, REGENERATE_ALL_COMMAND},
+    ROOT_DIR,
+};
+
+#[derive(clap::Args)]
+pub(crate) struct Args {
+    /// Write the generated table to stdout (rather than to `crates/ty/docs/configuration.md`).
+    #[arg(long, default_value_t, value_enum)]
+    pub(crate) mode: Mode,
+}
+
+pub(crate) fn main(args: &Args) -> anyhow::Result<()> {
+    let mut output = String::new();
+    let file_name = "crates/ty/docs/configuration.md";
+    let markdown_path = PathBuf::from(ROOT_DIR).join(file_name);
+
+    generate_set(
+        &mut output,
+        Set::Toplevel(Options::metadata()),
+        &mut Vec::new(),
+    );
+
+    match args.mode {
+        Mode::DryRun => {
+            println!("{output}");
+        }
+        Mode::Check => {
+            let current = std::fs::read_to_string(&markdown_path)?;
+            if output == current {
+                println!("Up-to-date: {file_name}",);
+            } else {
+                let comparison = StrComparison::new(&current, &output);
+                bail!("{file_name} changed, please run `{REGENERATE_ALL_COMMAND}`:\n{comparison}",);
+            }
+        }
+        Mode::Write => {
+            let current = std::fs::read_to_string(&markdown_path)?;
+            if current == output {
+                println!("Up-to-date: {file_name}",);
+            } else {
+                println!("Updating: {file_name}",);
+                std::fs::write(markdown_path, output.as_bytes())?;
+            }
+        }
+    }
+
+    Ok(())
+}
+
+fn generate_set(output: &mut String, set: Set, parents: &mut Vec<Set>) {
+    match &set {
+        Set::Toplevel(_) => {
+            output.push_str("# Configuration\n");
+        }
+        Set::Named { name, .. } => {
+            let title = parents
+                .iter()
+                .filter_map(|set| set.name())
+                .chain(std::iter::once(name.as_str()))
+                .join(".");
+            writeln!(output, "## `{title}`\n",).unwrap();
+        }
+    }
+
+    if let Some(documentation) = set.metadata().documentation() {
+        output.push_str(documentation);
+        output.push('\n');
+        output.push('\n');
+    }
+
+    let mut visitor = CollectOptionsVisitor::default();
+    set.metadata().record(&mut visitor);
+
+    let (mut fields, mut sets) = (visitor.fields, visitor.groups);
+
+    fields.sort_unstable_by(|(name, _), (name2, _)| name.cmp(name2));
+    sets.sort_unstable_by(|(name, _), (name2, _)| name.cmp(name2));
+
+    parents.push(set);
+
+    // Generate the fields.
+    for (name, field) in &fields {
+        emit_field(output, name, field, parents.as_slice());
+        output.push_str("---\n\n");
+    }
+
+    // Generate all the sub-sets.
+    for (set_name, sub_set) in &sets {
+        generate_set(
+            output,
+            Set::Named {
+                name: set_name.to_string(),
+                set: *sub_set,
+            },
+            parents,
+        );
+    }
+
+    parents.pop();
+}
+
+enum Set {
+    Toplevel(OptionSet),
+    Named { name: String, set: OptionSet },
+}
+
+impl Set {
+    fn name(&self) -> Option<&str> {
+        match self {
+            Set::Toplevel(_) => None,
+            Set::Named { name, .. } => Some(name),
+        }
+    }
+
+    fn metadata(&self) -> &OptionSet {
+        match self {
+            Set::Toplevel(set) => set,
+            Set::Named { set, .. } => set,
+        }
+    }
+}
+
+fn emit_field(output: &mut String, name: &str, field: &OptionField, parents: &[Set]) {
+    let header_level = if parents.is_empty() { "###" } else { "####" };
+
+    let _ = writeln!(output, "{header_level} `{name}`");
+
+    output.push('\n');
+
+    if let Some(deprecated) = &field.deprecated {
+        output.push_str("> [!WARN] \"Deprecated\"\n");
+        output.push_str("> This option has been deprecated");
+
+        if let Some(since) = deprecated.since {
+            write!(output, " in {since}").unwrap();
+        }
+
+        output.push('.');
+
+        if let Some(message) = deprecated.message {
+            writeln!(output, " {message}").unwrap();
+        }
+
+        output.push('\n');
+    }
+
+    output.push_str(field.doc);
+    output.push_str("\n\n");
+    let _ = writeln!(output, "**Default value**: `{}`", field.default);
+    output.push('\n');
+    let _ = writeln!(output, "**Type**: `{}`", field.value_type);
+    output.push('\n');
+    output.push_str("**Example usage** (`pyproject.toml`):\n\n");
+    output.push_str(&format_example(
+        &format_header(
+            field.scope,
+            field.example,
+            parents,
+            ConfigurationFile::PyprojectToml,
+        ),
+        field.example,
+    ));
+    output.push('\n');
+}
+
+fn format_example(header: &str, content: &str) -> String {
+    if header.is_empty() {
+        format!("```toml\n{content}\n```\n",)
+    } else {
+        format!("```toml\n{header}\n{content}\n```\n",)
+    }
+}
+
+/// Format the TOML header for the example usage for a given option.
+///
+/// For example: `[tool.ruff.format]` or `[tool.ruff.lint.isort]`.
+fn format_header(
+    scope: Option<&str>,
+    example: &str,
+    parents: &[Set],
+    configuration: ConfigurationFile,
+) -> String {
+    let tool_parent = match configuration {
+        ConfigurationFile::PyprojectToml => Some("tool.ty"),
+        ConfigurationFile::TyToml => None,
+    };
+
+    let header = tool_parent
+        .into_iter()
+        .chain(parents.iter().filter_map(|parent| parent.name()))
+        .chain(scope)
+        .join(".");
+
+    // Ex) `[[tool.ty.xx]]`
+    if example.starts_with(&format!("[[{header}")) {
+        return String::new();
+    }
+    // Ex) `[tool.ty.rules]`
+    if example.starts_with(&format!("[{header}")) {
+        return String::new();
+    }
+
+    if header.is_empty() {
+        String::new()
+    } else {
+        format!("[{header}]")
+    }
+}
+
+#[derive(Default)]
+struct CollectOptionsVisitor {
+    groups: Vec<(String, OptionSet)>,
+    fields: Vec<(String, OptionField)>,
+}
+
+impl Visit for CollectOptionsVisitor {
+    fn record_set(&mut self, name: &str, group: OptionSet) {
+        self.groups.push((name.to_owned(), group));
+    }
+
+    fn record_field(&mut self, name: &str, field: OptionField) {
+        self.fields.push((name.to_owned(), field));
+    }
+}
+
+#[derive(Debug, Copy, Clone)]
+enum ConfigurationFile {
+    PyprojectToml,
+    #[expect(dead_code)]
+    TyToml,
+}
+
+#[cfg(test)]
+mod tests {
+    use anyhow::Result;
+
+    use crate::generate_all::Mode;
+
+    use super::{main, Args};
+
+    #[test]
+    fn ty_configuration_markdown_up_to_date() -> Result<()> {
+        main(&Args { mode: Mode::Check })?;
+        Ok(())
+    }
+}

crates/ruff_dev/src/generate_ty_rules.rs

@@ -0,0 +1,143 @@
+//! Generates the rules table for ty
+
+use std::borrow::Cow;
+use std::fmt::Write as _;
+use std::fs;
+use std::path::PathBuf;
+
+use anyhow::{bail, Result};
+use itertools::Itertools as _;
+use pretty_assertions::StrComparison;
+
+use crate::generate_all::{Mode, REGENERATE_ALL_COMMAND};
+use crate::ROOT_DIR;
+
+#[derive(clap::Args)]
+pub(crate) struct Args {
+    /// Write the generated table to stdout (rather than to `ty.schema.json`).
+    #[arg(long, default_value_t, value_enum)]
+    pub(crate) mode: Mode,
+}
+
+pub(crate) fn main(args: &Args) -> Result<()> {
+    let markdown = generate_markdown();
+    let filename = "crates/ty/docs/rules.md";
+    let schema_path = PathBuf::from(ROOT_DIR).join(filename);
+
+    match args.mode {
+        Mode::DryRun => {
+            println!("{markdown}");
+        }
+        Mode::Check => {
+            let current = fs::read_to_string(schema_path)?;
+            if current == markdown {
+                println!("Up-to-date: {filename}");
+            } else {
+                let comparison = StrComparison::new(&current, &markdown);
+                bail!("{filename} changed, please run `{REGENERATE_ALL_COMMAND}`:\n{comparison}");
+            }
+        }
+        Mode::Write => {
+            let current = fs::read_to_string(&schema_path)?;
+            if current == markdown {
+                println!("Up-to-date: {filename}");
+            } else {
+                println!("Updating: {filename}");
+                fs::write(schema_path, markdown.as_bytes())?;
+            }
+        }
+    }
+
+    Ok(())
+}
+
+fn generate_markdown() -> String {
+    let registry = &*ty_project::DEFAULT_LINT_REGISTRY;
+
+    let mut output = String::new();
+
+    let _ = writeln!(&mut output, "# Rules\n");
+
+    let mut lints: Vec<_> = registry.lints().iter().collect();
+    lints.sort_by(|a, b| {
+        a.default_level()
+            .cmp(&b.default_level())
+            .reverse()
+            .then_with(|| a.name().cmp(&b.name()))
+    });
+
+    for lint in lints {
+        let _ = writeln!(&mut output, "## `{rule_name}`\n", rule_name = lint.name());
+
+        // Increase the header-level by one
+        let documentation = lint
+            .documentation_lines()
+            .map(|line| {
+                if line.starts_with('#') {
+                    Cow::Owned(format!("#{line}"))
+                } else {
+                    Cow::Borrowed(line)
+                }
+            })
+            .join("\n");
+
+        let _ = writeln!(
+            &mut output,
+            r#"**Default level**: {level}
+
+<details>
+<summary>{summary}</summary>
+
+{documentation}
+
+### Links
+* [Related issues](https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20{encoded_name})
+* [View source](https://github.com/astral-sh/ruff/blob/main/{file}#L{line})
+</details>
+"#,
+            level = lint.default_level(),
+            // GitHub doesn't support markdown in `summary` headers
+            summary = replace_inline_code(lint.summary()),
+            encoded_name = url::form_urlencoded::byte_serialize(lint.name().as_str().as_bytes())
+                .collect::<String>(),
+            file = url::form_urlencoded::byte_serialize(lint.file().replace('\\', "/").as_bytes())
+                .collect::<String>(),
+            line = lint.line(),
+        );
+    }
+
+    output
+}
+
+/// Replaces inline code blocks (`code`) with `<code>code</code>`
+fn replace_inline_code(input: &str) -> String {
+    let mut output = String::new();
+    let mut parts = input.split('`');
+
+    while let Some(before) = parts.next() {
+        if let Some(between) = parts.next() {
+            output.push_str(before);
+            output.push_str("<code>");
+            output.push_str(between);
+            output.push_str("</code>");
+        } else {
+            output.push_str(before);
+        }
+    }
+
+    output
+}
+
+#[cfg(test)]
+mod tests {
+    use anyhow::Result;
+
+    use crate::generate_all::Mode;
+
+    use super::{main, Args};
+
+    #[test]
+    fn ty_rules_up_to_date() -> Result<()> {
+        main(&Args { mode: Mode::Check })
+    }
+}

crates/ruff_dev/src/generate_ty_schema.rs

@@ -1,5 +1,3 @@
-#![allow(clippy::print_stdout, clippy::print_stderr)]
-
 use std::fs;
 use std::path::PathBuf;
 
@@ -9,11 +7,11 @@ use schemars::schema_for;
 
 use crate::generate_all::{Mode, REGENERATE_ALL_COMMAND};
 use crate::ROOT_DIR;
-use red_knot_project::metadata::options::Options;
+use ty_project::metadata::options::Options;
 
 #[derive(clap::Args)]
 pub(crate) struct Args {
-    /// Write the generated table to stdout (rather than to `knot.schema.json`).
+    /// Write the generated table to stdout (rather than to `ty.schema.json`).
     #[arg(long, default_value_t, value_enum)]
     pub(crate) mode: Mode,
 }
@@ -21,7 +19,7 @@ pub(crate) struct Args {
 pub(crate) fn main(args: &Args) -> Result<()> {
     let schema = schema_for!(Options);
     let schema_string = serde_json::to_string_pretty(&schema).unwrap();
-    let filename = "knot.schema.json";
+    let filename = "ty.schema.json";
     let schema_path = PathBuf::from(ROOT_DIR).join(filename);
 
     match args.mode {
@@ -62,7 +60,7 @@ mod tests {
 
     #[test]
     fn test_generate_json_schema() -> Result<()> {
-        let mode = if env::var("KNOT_UPDATE_SCHEMA").as_deref() == Ok("1") {
+        let mode = if env::var("TY_UPDATE_SCHEMA").as_deref() == Ok("1") {
             Mode::Write
         } else {
             Mode::Check

crates/ruff_dev/src/main.rs

@@ -2,6 +2,8 @@
 //!
 //! Within the ruff repository you can run it with `cargo dev`.
 
+#![allow(clippy::print_stdout, clippy::print_stderr)]
+
 use anyhow::Result;
 use clap::{Parser, Subcommand};
 use ruff::{args::GlobalConfigArgs, check};
@@ -13,9 +15,12 @@ mod generate_all;
 mod generate_cli_help;
 mod generate_docs;
 mod generate_json_schema;
-mod generate_knot_schema;
 mod generate_options;
 mod generate_rules_table;
+mod generate_ty_cli_reference;
+mod generate_ty_options;
+mod generate_ty_rules;
+mod generate_ty_schema;
 mod print_ast;
 mod print_cst;
 mod print_tokens;
@@ -34,18 +39,20 @@ struct Args {
 }
 
 #[derive(Subcommand)]
-#[allow(clippy::large_enum_variant)]
+#[expect(clippy::large_enum_variant)]
 enum Command {
     /// Run all code and documentation generation steps.
     GenerateAll(generate_all::Args),
     /// Generate JSON schema for the TOML configuration file.
     GenerateJSONSchema(generate_json_schema::Args),
-    /// Generate JSON schema for the Red Knot TOML configuration file.
-    GenerateKnotSchema(generate_knot_schema::Args),
+    /// Generate JSON schema for the ty TOML configuration file.
+    GenerateTySchema(generate_ty_schema::Args),
     /// Generate a Markdown-compatible table of supported lint rules.
     GenerateRulesTable,
+    GenerateTyRules(generate_ty_rules::Args),
     /// Generate a Markdown-compatible listing of configuration options.
     GenerateOptions,
+    GenerateTyOptions(generate_ty_options::Args),
     /// Generate CLI help.
     GenerateCliHelp(generate_cli_help::Args),
     /// Generate Markdown docs.
@@ -82,13 +89,15 @@ fn main() -> Result<ExitCode> {
         command,
         global_options,
     } = Args::parse();
-    #[allow(clippy::print_stdout)]
+    #[expect(clippy::print_stdout)]
     match command {
         Command::GenerateAll(args) => generate_all::main(&args)?,
         Command::GenerateJSONSchema(args) => generate_json_schema::main(&args)?,
-        Command::GenerateKnotSchema(args) => generate_knot_schema::main(&args)?,
+        Command::GenerateTySchema(args) => generate_ty_schema::main(&args)?,
         Command::GenerateRulesTable => println!("{}", generate_rules_table::generate()),
+        Command::GenerateTyRules(args) => generate_ty_rules::main(&args)?,
         Command::GenerateOptions => println!("{}", generate_options::generate()),
+        Command::GenerateTyOptions(args) => generate_ty_options::main(&args)?,
         Command::GenerateCliHelp(args) => generate_cli_help::main(&args)?,
         Command::GenerateDocs(args) => generate_docs::main(&args)?,
         Command::PrintAST(args) => print_ast::main(&args)?,

crates/ruff_dev/src/print_ast.rs

@@ -1,5 +1,4 @@
 //! Print the AST for a given Python file.
-#![allow(clippy::print_stdout, clippy::print_stderr)]
 
 use std::path::PathBuf;
 

crates/ruff_dev/src/print_cst.rs

@@ -1,5 +1,4 @@
 //! Print the `LibCST` CST for a given Python file.
-#![allow(clippy::print_stdout, clippy::print_stderr)]
 
 use std::fs;
 use std::path::PathBuf;

crates/ruff_dev/src/print_tokens.rs

@@ -1,5 +1,4 @@
 //! Print the token stream for a given Python file.
-#![allow(clippy::print_stdout, clippy::print_stderr)]
 
 use std::path::PathBuf;
 

crates/ruff_dev/src/round_trip.rs

@@ -1,5 +1,4 @@
 //! Run round-trip source code generation on a given Python or Jupyter notebook file.
-#![allow(clippy::print_stdout, clippy::print_stderr)]
 
 use std::fs;
 use std::path::PathBuf;

crates/ruff_formatter/src/format_element.rs

@@ -519,7 +519,7 @@ impl TextWidth {
             let char_width = match c {
                 '\t' => indent_width.value(),
                 '\n' => return TextWidth::Multiline,
-                #[allow(clippy::cast_possible_truncation)]
+                #[expect(clippy::cast_possible_truncation)]
                 c => c.width().unwrap_or(0) as u32,
             };
             width += char_width;

crates/ruff_formatter/src/format_element/document.rs

@@ -280,7 +280,7 @@ impl Format<IrFormatContext<'_>> for &[FormatElement] {
                 | FormatElement::SourceCodeSlice { .. }) => {
                     fn write_escaped(element: &FormatElement, f: &mut Formatter<IrFormatContext>) {
                         let (text, text_width) = match element {
-                            #[allow(clippy::cast_possible_truncation)]
+                            #[expect(clippy::cast_possible_truncation)]
                             FormatElement::Token { text } => {
                                 (*text, TextWidth::Width(Width::new(text.len() as u32)))
                             }

crates/ruff_formatter/src/format_element/tag.rs

@@ -379,7 +379,7 @@ impl PartialEq for LabelId {
 }
 
 impl LabelId {
-    #[allow(clippy::needless_pass_by_value)]
+    #[expect(clippy::needless_pass_by_value)]
     pub fn of<T: LabelDefinition>(label: T) -> Self {
         Self {
             value: label.value(),

crates/ruff_formatter/src/lib.rs

@@ -92,7 +92,7 @@ impl std::fmt::Display for IndentStyle {
     }
 }
 
-/// The visual width of a indentation.
+/// The visual width of an indentation.
 ///
 /// Determines the visual width of a tab character (`\t`) and the number of
 /// spaces per indent when using [`IndentStyle::Space`].
@@ -207,7 +207,7 @@ pub trait FormatOptions {
     /// What's the max width of a line. Defaults to 80.
     fn line_width(&self) -> LineWidth;
 
-    /// Derives the print options from the these format options
+    /// Derives the print options from these format options
     fn as_print_options(&self) -> PrinterOptions;
 }
 
@@ -925,7 +925,7 @@ pub struct FormatState<Context> {
     group_id_builder: UniqueGroupIdBuilder,
 }
 
-#[allow(clippy::missing_fields_in_debug)]
+#[expect(clippy::missing_fields_in_debug)]
 impl<Context> std::fmt::Debug for FormatState<Context>
 where
     Context: std::fmt::Debug,

crates/ruff_formatter/src/printer/mod.rs

@@ -331,7 +331,7 @@ impl<'a> Printer<'a> {
             FormatElement::Tag(StartVerbatim(kind)) => {
                 if let VerbatimKind::Verbatim { length } = kind {
                     // SAFETY: Ruff only supports formatting files <= 4GB
-                    #[allow(clippy::cast_possible_truncation)]
+                    #[expect(clippy::cast_possible_truncation)]
                     self.state.verbatim_markers.push(TextRange::at(
                         TextSize::from(self.state.buffer.len() as u32),
                         *length,
@@ -464,7 +464,7 @@ impl<'a> Printer<'a> {
         self.push_marker();
 
         match text {
-            #[allow(clippy::cast_possible_truncation)]
+            #[expect(clippy::cast_possible_truncation)]
             Text::Token(token) => {
                 self.state.buffer.push_str(token);
                 self.state.line_width += token.len() as u32;
@@ -831,7 +831,7 @@ impl<'a> Printer<'a> {
         } else {
             self.state.buffer.push(char);
 
-            #[allow(clippy::cast_possible_truncation)]
+            #[expect(clippy::cast_possible_truncation)]
             let char_width = if char == '\t' {
                 self.options.indent_width.value()
             } else {
@@ -1480,7 +1480,7 @@ impl<'a, 'print> FitsMeasurer<'a, 'print> {
             u32::from(indent.level()) * self.options().indent_width() + u32::from(indent.align());
 
         match text {
-            #[allow(clippy::cast_possible_truncation)]
+            #[expect(clippy::cast_possible_truncation)]
             Text::Token(token) => {
                 self.state.line_width += token.len() as u32;
             }
@@ -1511,7 +1511,7 @@ impl<'a, 'print> FitsMeasurer<'a, 'print> {
                                 }
                             }
                             // SAFETY: A u32 is sufficient to format files <= 4GB
-                            #[allow(clippy::cast_possible_truncation)]
+                            #[expect(clippy::cast_possible_truncation)]
                             c => c.width().unwrap_or(0) as u32,
                         };
                         self.state.line_width += char_width;