leave some TODOs

Here are a bunch of (variously failing and passing) mdtests that reflect
the kinds of issues people encounter when running ty over an entire
workspace without sufficient hand-holding (especially because in the IDE
it is unclear *how* to provide that hand-holding).

.config/nextest.toml

@@ -7,10 +7,6 @@ serial = { max-threads = 1 }
 filter = 'binary(file_watching)'
 test-group = 'serial'
 
-[[profile.default.overrides]]
-filter = 'binary(e2e)'
-test-group = 'serial'
-
 [profile.ci]
 # Print out output for failing tests as soon as they fail, and also at the end
 # of the run (for easy scrollability).

.github/workflows/build-binaries.yml

@@ -43,7 +43,7 @@ jobs:
         with:
           submodules: recursive
           persist-credentials: false
-      - uses: actions/setup-python@e797f83bcb11b83ae66e0230d6156d7c80228e7c # v6.0.0
+      - uses: actions/setup-python@83679a892e2d95755f2dac6acb0bfd1e9ac5d548 # v6.1.0
         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@e797f83bcb11b83ae66e0230d6156d7c80228e7c # v6.0.0
+      - uses: actions/setup-python@83679a892e2d95755f2dac6acb0bfd1e9ac5d548 # v6.1.0
         with:
           python-version: ${{ env.PYTHON_VERSION }}
           architecture: x64
@@ -114,7 +114,7 @@ jobs:
         with:
           submodules: recursive
           persist-credentials: false
-      - uses: actions/setup-python@e797f83bcb11b83ae66e0230d6156d7c80228e7c # v6.0.0
+      - uses: actions/setup-python@83679a892e2d95755f2dac6acb0bfd1e9ac5d548 # v6.1.0
         with:
           python-version: ${{ env.PYTHON_VERSION }}
           architecture: arm64
@@ -170,7 +170,7 @@ jobs:
         with:
           submodules: recursive
           persist-credentials: false
-      - uses: actions/setup-python@e797f83bcb11b83ae66e0230d6156d7c80228e7c # v6.0.0
+      - uses: actions/setup-python@83679a892e2d95755f2dac6acb0bfd1e9ac5d548 # v6.1.0
         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@e797f83bcb11b83ae66e0230d6156d7c80228e7c # v6.0.0
+      - uses: actions/setup-python@83679a892e2d95755f2dac6acb0bfd1e9ac5d548 # v6.1.0
         with:
           python-version: ${{ env.PYTHON_VERSION }}
           architecture: x64
@@ -300,7 +300,7 @@ jobs:
         with:
           submodules: recursive
           persist-credentials: false
-      - uses: actions/setup-python@e797f83bcb11b83ae66e0230d6156d7c80228e7c # v6.0.0
+      - uses: actions/setup-python@83679a892e2d95755f2dac6acb0bfd1e9ac5d548 # v6.1.0
         with:
           python-version: ${{ env.PYTHON_VERSION }}
       - name: "Prep README.md"
@@ -365,7 +365,7 @@ jobs:
         with:
           submodules: recursive
           persist-credentials: false
-      - uses: actions/setup-python@e797f83bcb11b83ae66e0230d6156d7c80228e7c # v6.0.0
+      - uses: actions/setup-python@83679a892e2d95755f2dac6acb0bfd1e9ac5d548 # v6.1.0
         with:
           python-version: ${{ env.PYTHON_VERSION }}
           architecture: x64
@@ -431,7 +431,7 @@ jobs:
         with:
           submodules: recursive
           persist-credentials: false
-      - uses: actions/setup-python@e797f83bcb11b83ae66e0230d6156d7c80228e7c # v6.0.0
+      - uses: actions/setup-python@83679a892e2d95755f2dac6acb0bfd1e9ac5d548 # v6.1.0
         with:
           python-version: ${{ env.PYTHON_VERSION }}
       - name: "Prep README.md"

.github/workflows/ci.yaml

@@ -230,7 +230,7 @@ jobs:
       - uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5.0.0
         with:
           persist-credentials: false
-      - uses: Swatinem/rust-cache@f13886b937689c021905a6b90929199931d60db1 # v2.8.1
+      - uses: Swatinem/rust-cache@779680da715d629ac1d338a641029a2f4372abb5 # v2.8.2
         with:
           save-if: ${{ github.ref == 'refs/heads/main' }}
       - name: "Install Rust toolchain"
@@ -252,7 +252,7 @@ jobs:
       - uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5.0.0
         with:
           persist-credentials: false
-      - uses: Swatinem/rust-cache@f13886b937689c021905a6b90929199931d60db1 # v2.8.1
+      - uses: Swatinem/rust-cache@779680da715d629ac1d338a641029a2f4372abb5 # v2.8.2
         with:
           shared-key: ruff-linux-debug
           save-if: ${{ github.ref == 'refs/heads/main' }}
@@ -261,11 +261,11 @@ jobs:
       - name: "Install mold"
         uses: rui314/setup-mold@725a8794d15fc7563f59595bd9556495c0564878 # v1
       - name: "Install cargo nextest"
-        uses: taiki-e/install-action@f79fe7514db78f0a7bdba3cb6dd9c1baa7d046d9 # v2.62.56
+        uses: taiki-e/install-action@3575e532701a5fc614b0c842e4119af4cc5fd16d # v2.62.60
         with:
           tool: cargo-nextest
       - name: "Install cargo insta"
-        uses: taiki-e/install-action@f79fe7514db78f0a7bdba3cb6dd9c1baa7d046d9 # v2.62.56
+        uses: taiki-e/install-action@3575e532701a5fc614b0c842e4119af4cc5fd16d # v2.62.60
         with:
           tool: cargo-insta
       - name: "Install uv"
@@ -315,7 +315,7 @@ jobs:
       - uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5.0.0
         with:
           persist-credentials: false
-      - uses: Swatinem/rust-cache@f13886b937689c021905a6b90929199931d60db1 # v2.8.1
+      - uses: Swatinem/rust-cache@779680da715d629ac1d338a641029a2f4372abb5 # v2.8.2
         with:
           save-if: ${{ github.ref == 'refs/heads/main' }}
       - name: "Install Rust toolchain"
@@ -323,7 +323,7 @@ jobs:
       - name: "Install mold"
         uses: rui314/setup-mold@725a8794d15fc7563f59595bd9556495c0564878 # v1
       - name: "Install cargo nextest"
-        uses: taiki-e/install-action@f79fe7514db78f0a7bdba3cb6dd9c1baa7d046d9 # v2.62.56
+        uses: taiki-e/install-action@3575e532701a5fc614b0c842e4119af4cc5fd16d # v2.62.60
         with:
           tool: cargo-nextest
       - name: "Install uv"
@@ -350,13 +350,13 @@ jobs:
       - uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5.0.0
         with:
           persist-credentials: false
-      - uses: Swatinem/rust-cache@f13886b937689c021905a6b90929199931d60db1 # v2.8.1
+      - uses: Swatinem/rust-cache@779680da715d629ac1d338a641029a2f4372abb5 # v2.8.2
         with:
           save-if: ${{ github.ref == 'refs/heads/main' }}
       - name: "Install Rust toolchain"
         run: rustup show
       - name: "Install cargo nextest"
-        uses: taiki-e/install-action@f79fe7514db78f0a7bdba3cb6dd9c1baa7d046d9 # v2.62.56
+        uses: taiki-e/install-action@3575e532701a5fc614b0c842e4119af4cc5fd16d # v2.62.60
         with:
           tool: cargo-nextest
       - name: "Install uv"
@@ -378,7 +378,7 @@ jobs:
       - uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5.0.0
         with:
           persist-credentials: false
-      - uses: Swatinem/rust-cache@f13886b937689c021905a6b90929199931d60db1 # v2.8.1
+      - uses: Swatinem/rust-cache@779680da715d629ac1d338a641029a2f4372abb5 # v2.8.2
         with:
           save-if: ${{ github.ref == 'refs/heads/main' }}
       - name: "Install Rust toolchain"
@@ -415,7 +415,7 @@ jobs:
         with:
           file: "Cargo.toml"
           field: "workspace.package.rust-version"
-      - uses: Swatinem/rust-cache@f13886b937689c021905a6b90929199931d60db1 # v2.8.1
+      - uses: Swatinem/rust-cache@779680da715d629ac1d338a641029a2f4372abb5 # v2.8.2
         with:
           save-if: ${{ github.ref == 'refs/heads/main' }}
       - name: "Install Rust toolchain"
@@ -439,7 +439,7 @@ jobs:
       - uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5.0.0
         with:
           persist-credentials: false
-      - uses: Swatinem/rust-cache@f13886b937689c021905a6b90929199931d60db1 # v2.8.1
+      - uses: Swatinem/rust-cache@779680da715d629ac1d338a641029a2f4372abb5 # v2.8.2
         with:
           workspaces: "fuzz -> target"
           save-if: ${{ github.ref == 'refs/heads/main' }}
@@ -448,7 +448,7 @@ jobs:
       - name: "Install mold"
         uses: rui314/setup-mold@725a8794d15fc7563f59595bd9556495c0564878 # v1
       - name: "Install cargo-binstall"
-        uses: cargo-bins/cargo-binstall@ae04fb5e853ae6cd3ad7de4a1d554a8b646d12aa # v1.15.11
+        uses: cargo-bins/cargo-binstall@3fc81674af4165a753833a94cae9f91d8849049f # v1.16.2
       - name: "Install cargo-fuzz"
         # Download the latest version from quick install and not the github releases because github releases only has MUSL targets.
         run: cargo binstall cargo-fuzz --force  --disable-strategies crate-meta-data --no-confirm
@@ -467,7 +467,7 @@ jobs:
         with:
           persist-credentials: false
       - uses: astral-sh/setup-uv@1e862dfacbd1d6d858c55d9b792c756523627244 # v7.1.4
-      - uses: Swatinem/rust-cache@f13886b937689c021905a6b90929199931d60db1 # v2.8.1
+      - uses: Swatinem/rust-cache@779680da715d629ac1d338a641029a2f4372abb5 # v2.8.2
         with:
           shared-key: ruff-linux-debug
           save-if: false
@@ -498,7 +498,7 @@ jobs:
       - uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5.0.0
         with:
           persist-credentials: false
-      - uses: Swatinem/rust-cache@f13886b937689c021905a6b90929199931d60db1 # v2.8.1
+      - uses: Swatinem/rust-cache@779680da715d629ac1d338a641029a2f4372abb5 # v2.8.2
         with:
           save-if: ${{ github.ref == 'refs/heads/main' }}
       - uses: astral-sh/setup-uv@1e862dfacbd1d6d858c55d9b792c756523627244 # v7.1.4
@@ -547,7 +547,7 @@ jobs:
       - name: "Install mold"
         uses: rui314/setup-mold@725a8794d15fc7563f59595bd9556495c0564878 # v1
 
-      - uses: Swatinem/rust-cache@f13886b937689c021905a6b90929199931d60db1 # v2.8.1
+      - uses: Swatinem/rust-cache@779680da715d629ac1d338a641029a2f4372abb5 # v2.8.2
         with:
           shared-key: ruff-linux-debug
           save-if: false
@@ -643,7 +643,7 @@ jobs:
           fetch-depth: 0
           persist-credentials: false
       - uses: astral-sh/setup-uv@1e862dfacbd1d6d858c55d9b792c756523627244 # v7.1.4
-      - uses: Swatinem/rust-cache@f13886b937689c021905a6b90929199931d60db1 # v2.8.1
+      - uses: Swatinem/rust-cache@779680da715d629ac1d338a641029a2f4372abb5 # v2.8.2
         with:
           save-if: ${{ github.ref == 'refs/heads/main' }}
       - name: "Install Rust toolchain"
@@ -688,7 +688,7 @@ jobs:
       - uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5.0.0
         with:
           persist-credentials: false
-      - uses: cargo-bins/cargo-binstall@ae04fb5e853ae6cd3ad7de4a1d554a8b646d12aa # v1.15.11
+      - uses: cargo-bins/cargo-binstall@3fc81674af4165a753833a94cae9f91d8849049f # v1.16.2
       - run: cargo binstall --no-confirm cargo-shear
       - run: cargo shear
 
@@ -702,7 +702,7 @@ jobs:
         with:
           persist-credentials: false
       - uses: astral-sh/setup-uv@1e862dfacbd1d6d858c55d9b792c756523627244 # v7.1.4
-      - uses: Swatinem/rust-cache@f13886b937689c021905a6b90929199931d60db1 # v2.8.1
+      - uses: Swatinem/rust-cache@779680da715d629ac1d338a641029a2f4372abb5 # v2.8.2
         with:
           save-if: ${{ github.ref == 'refs/heads/main' }}
       - name: "Install Rust toolchain"
@@ -723,11 +723,11 @@ jobs:
       - uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5.0.0
         with:
           persist-credentials: false
-      - uses: actions/setup-python@e797f83bcb11b83ae66e0230d6156d7c80228e7c # v6.0.0
+      - uses: actions/setup-python@83679a892e2d95755f2dac6acb0bfd1e9ac5d548 # v6.1.0
         with:
           python-version: ${{ env.PYTHON_VERSION }}
           architecture: x64
-      - uses: Swatinem/rust-cache@f13886b937689c021905a6b90929199931d60db1 # v2.8.1
+      - uses: Swatinem/rust-cache@779680da715d629ac1d338a641029a2f4372abb5 # v2.8.2
         with:
           save-if: ${{ github.ref == 'refs/heads/main' }}
       - name: "Prep README.md"
@@ -753,7 +753,7 @@ jobs:
         with:
           persist-credentials: false
       - uses: astral-sh/setup-uv@1e862dfacbd1d6d858c55d9b792c756523627244 # v7.1.4
-      - uses: Swatinem/rust-cache@f13886b937689c021905a6b90929199931d60db1 # v2.8.1
+      - uses: Swatinem/rust-cache@779680da715d629ac1d338a641029a2f4372abb5 # v2.8.2
         with:
           save-if: ${{ github.ref == 'refs/heads/main' }}
       - uses: actions/setup-node@2028fbc5c25fe9cf00d9f06a71cc4710d4507903 # v6.0.0
@@ -785,7 +785,7 @@ jobs:
       - uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5.0.0
         with:
           persist-credentials: false
-      - uses: Swatinem/rust-cache@f13886b937689c021905a6b90929199931d60db1 # v2.8.1
+      - uses: Swatinem/rust-cache@779680da715d629ac1d338a641029a2f4372abb5 # v2.8.2
         with:
           save-if: ${{ github.ref == 'refs/heads/main' }}
       - name: "Add SSH key"
@@ -829,7 +829,7 @@ jobs:
       - uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5.0.0
         with:
           persist-credentials: false
-      - uses: Swatinem/rust-cache@f13886b937689c021905a6b90929199931d60db1 # v2.8.1
+      - uses: Swatinem/rust-cache@779680da715d629ac1d338a641029a2f4372abb5 # v2.8.2
         with:
           save-if: ${{ github.ref == 'refs/heads/main' }}
       - name: "Install Rust toolchain"
@@ -857,7 +857,7 @@ jobs:
         with:
           persist-credentials: false
 
-      - uses: Swatinem/rust-cache@f13886b937689c021905a6b90929199931d60db1 # v2.8.1
+      - uses: Swatinem/rust-cache@779680da715d629ac1d338a641029a2f4372abb5 # v2.8.2
         with:
           shared-key: ruff-linux-debug
           save-if: false
@@ -875,7 +875,7 @@ jobs:
           repository: "astral-sh/ruff-lsp"
           path: ruff-lsp
 
-      - uses: actions/setup-python@e797f83bcb11b83ae66e0230d6156d7c80228e7c # v6.0.0
+      - uses: actions/setup-python@83679a892e2d95755f2dac6acb0bfd1e9ac5d548 # v6.1.0
         with:
           # installation fails on 3.13 and newer
           python-version: "3.12"
@@ -908,7 +908,7 @@ jobs:
           persist-credentials: false
       - name: "Install Rust toolchain"
         run: rustup target add wasm32-unknown-unknown
-      - uses: Swatinem/rust-cache@f13886b937689c021905a6b90929199931d60db1 # v2.8.1
+      - uses: Swatinem/rust-cache@779680da715d629ac1d338a641029a2f4372abb5 # v2.8.2
         with:
           save-if: ${{ github.ref == 'refs/heads/main' }}
       - uses: actions/setup-node@2028fbc5c25fe9cf00d9f06a71cc4710d4507903 # v6.0.0
@@ -918,7 +918,7 @@ jobs:
           cache-dependency-path: playground/package-lock.json
       - uses: jetli/wasm-bindgen-action@20b33e20595891ab1a0ed73145d8a21fc96e7c29 # v0.2.0
       - name: "Install Node dependencies"
-        run: npm ci
+        run: npm ci --ignore-scripts
         working-directory: playground
       - name: "Build playgrounds"
         run: npm run dev:wasm
@@ -942,13 +942,16 @@ jobs:
         needs.determine_changes.outputs.linter == 'true'
       )
     timeout-minutes: 20
+    permissions:
+      contents: read # required for actions/checkout
+      id-token: write # required for OIDC authentication with CodSpeed
     steps:
       - name: "Checkout Branch"
         uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5.0.0
         with:
           persist-credentials: false
 
-      - uses: Swatinem/rust-cache@f13886b937689c021905a6b90929199931d60db1 # v2.8.1
+      - uses: Swatinem/rust-cache@779680da715d629ac1d338a641029a2f4372abb5 # v2.8.2
         with:
           save-if: ${{ github.ref == 'refs/heads/main' }}
       - uses: astral-sh/setup-uv@1e862dfacbd1d6d858c55d9b792c756523627244 # v7.1.4
@@ -957,7 +960,7 @@ jobs:
         run: rustup show
 
       - name: "Install codspeed"
-        uses: taiki-e/install-action@f79fe7514db78f0a7bdba3cb6dd9c1baa7d046d9 # v2.62.56
+        uses: taiki-e/install-action@3575e532701a5fc614b0c842e4119af4cc5fd16d # v2.62.60
         with:
           tool: cargo-codspeed
 
@@ -965,11 +968,10 @@ jobs:
         run: cargo codspeed build --features "codspeed,instrumented" --profile profiling --no-default-features -p ruff_benchmark --bench formatter --bench lexer --bench linter --bench parser
 
       - name: "Run benchmarks"
-        uses: CodSpeedHQ/action@6a8e2b874c338bf81cc5e8be715ada75908d3871 # v4.3.4
+        uses: CodSpeedHQ/action@346a2d8a8d9d38909abd0bc3d23f773110f076ad # v4.4.1
         with:
-          mode: instrumentation
+          mode: simulation
           run: cargo codspeed run
-          token: ${{ secrets.CODSPEED_TOKEN }}
 
   benchmarks-instrumented-ty:
     name: "benchmarks instrumented (ty)"
@@ -982,13 +984,16 @@ jobs:
         needs.determine_changes.outputs.ty == 'true'
       )
     timeout-minutes: 20
+    permissions:
+      contents: read # required for actions/checkout
+      id-token: write # required for OIDC authentication with CodSpeed
     steps:
       - name: "Checkout Branch"
         uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5.0.0
         with:
           persist-credentials: false
 
-      - uses: Swatinem/rust-cache@f13886b937689c021905a6b90929199931d60db1 # v2.8.1
+      - uses: Swatinem/rust-cache@779680da715d629ac1d338a641029a2f4372abb5 # v2.8.2
         with:
           save-if: ${{ github.ref == 'refs/heads/main' }}
       - uses: astral-sh/setup-uv@1e862dfacbd1d6d858c55d9b792c756523627244 # v7.1.4
@@ -997,7 +1002,7 @@ jobs:
         run: rustup show
 
       - name: "Install codspeed"
-        uses: taiki-e/install-action@f79fe7514db78f0a7bdba3cb6dd9c1baa7d046d9 # v2.62.56
+        uses: taiki-e/install-action@3575e532701a5fc614b0c842e4119af4cc5fd16d # v2.62.60
         with:
           tool: cargo-codspeed
 
@@ -1005,11 +1010,10 @@ jobs:
         run: cargo codspeed build --features "codspeed,instrumented" --profile profiling --no-default-features -p ruff_benchmark --bench ty
 
       - name: "Run benchmarks"
-        uses: CodSpeedHQ/action@6a8e2b874c338bf81cc5e8be715ada75908d3871 # v4.3.4
+        uses: CodSpeedHQ/action@346a2d8a8d9d38909abd0bc3d23f773110f076ad # v4.4.1
         with:
-          mode: instrumentation
+          mode: simulation
           run: cargo codspeed run
-          token: ${{ secrets.CODSPEED_TOKEN }}
 
   benchmarks-walltime:
     name: "benchmarks walltime (${{ matrix.benchmarks }})"
@@ -1017,6 +1021,9 @@ jobs:
     needs: determine_changes
     if: ${{ github.repository == 'astral-sh/ruff' && !contains(github.event.pull_request.labels.*.name, 'no-test') && (needs.determine_changes.outputs.ty == 'true' || github.ref == 'refs/heads/main') }}
     timeout-minutes: 20
+    permissions:
+      contents: read # required for actions/checkout
+      id-token: write # required for OIDC authentication with CodSpeed
     strategy:
       matrix:
         benchmarks:
@@ -1028,7 +1035,7 @@ jobs:
         with:
           persist-credentials: false
 
-      - uses: Swatinem/rust-cache@f13886b937689c021905a6b90929199931d60db1 # v2.8.1
+      - uses: Swatinem/rust-cache@779680da715d629ac1d338a641029a2f4372abb5 # v2.8.2
         with:
           save-if: ${{ github.ref == 'refs/heads/main' }}
       - uses: astral-sh/setup-uv@1e862dfacbd1d6d858c55d9b792c756523627244 # v7.1.4
@@ -1037,7 +1044,7 @@ jobs:
         run: rustup show
 
       - name: "Install codspeed"
-        uses: taiki-e/install-action@f79fe7514db78f0a7bdba3cb6dd9c1baa7d046d9 # v2.62.56
+        uses: taiki-e/install-action@3575e532701a5fc614b0c842e4119af4cc5fd16d # v2.62.60
         with:
           tool: cargo-codspeed
 
@@ -1045,7 +1052,7 @@ jobs:
         run: cargo codspeed build --features "codspeed,walltime" --profile profiling --no-default-features -p ruff_benchmark
 
       - name: "Run benchmarks"
-        uses: CodSpeedHQ/action@6a8e2b874c338bf81cc5e8be715ada75908d3871 # v4.3.4
+        uses: CodSpeedHQ/action@346a2d8a8d9d38909abd0bc3d23f773110f076ad # v4.4.1
         env:
           # enabling walltime flamegraphs adds ~6 minutes to the CI time, and they don't
           # appear to provide much useful insight for our walltime benchmarks right now
@@ -1054,4 +1061,3 @@ jobs:
         with:
           mode: walltime
           run: cargo codspeed run --bench ty_walltime "${{ matrix.benchmarks }}"
-          token: ${{ secrets.CODSPEED_TOKEN }}

.github/workflows/daily_fuzz.yaml

@@ -39,7 +39,7 @@ jobs:
         run: rustup show
       - name: "Install mold"
         uses: rui314/setup-mold@725a8794d15fc7563f59595bd9556495c0564878 # v1
-      - uses: Swatinem/rust-cache@f13886b937689c021905a6b90929199931d60db1 # v2.8.1
+      - uses: Swatinem/rust-cache@779680da715d629ac1d338a641029a2f4372abb5 # v2.8.2
       - name: Build ruff
         # A debug build means the script runs slower once it gets started,
         # but this is outweighed by the fact that a release build takes *much* longer to compile in CI

.github/workflows/mypy_primer.yaml

@@ -45,7 +45,7 @@ jobs:
       - name: Install the latest version of uv
         uses: astral-sh/setup-uv@1e862dfacbd1d6d858c55d9b792c756523627244 # v7.1.4
 
-      - uses: Swatinem/rust-cache@f13886b937689c021905a6b90929199931d60db1 # v2.8.1
+      - uses: Swatinem/rust-cache@779680da715d629ac1d338a641029a2f4372abb5 # v2.8.2
         with:
           workspaces: "ruff"
 
@@ -83,7 +83,7 @@ jobs:
       - name: Install the latest version of uv
         uses: astral-sh/setup-uv@1e862dfacbd1d6d858c55d9b792c756523627244 # v7.1.4
 
-      - uses: Swatinem/rust-cache@f13886b937689c021905a6b90929199931d60db1 # v2.8.1
+      - uses: Swatinem/rust-cache@779680da715d629ac1d338a641029a2f4372abb5 # v2.8.2
         with:
           workspaces: "ruff"
 

.github/workflows/publish-docs.yml

@@ -28,7 +28,7 @@ jobs:
           ref: ${{ inputs.ref }}
           persist-credentials: true
 
-      - uses: actions/setup-python@e797f83bcb11b83ae66e0230d6156d7c80228e7c # v6.0.0
+      - uses: actions/setup-python@83679a892e2d95755f2dac6acb0bfd1e9ac5d548 # v6.1.0
         with:
           python-version: 3.12
 
@@ -68,7 +68,7 @@ jobs:
       - name: "Install Rust toolchain"
         run: rustup show
 
-      - uses: Swatinem/rust-cache@f13886b937689c021905a6b90929199931d60db1 # v2.8.1
+      - uses: Swatinem/rust-cache@779680da715d629ac1d338a641029a2f4372abb5 # v2.8.2
 
       - name: "Install Insiders dependencies"
         if: ${{ env.MKDOCS_INSIDERS_SSH_KEY_EXISTS == 'true' }}

.github/workflows/publish-playground.yml

@@ -37,7 +37,7 @@ jobs:
           package-manager-cache: false
       - uses: jetli/wasm-bindgen-action@20b33e20595891ab1a0ed73145d8a21fc96e7c29 # v0.2.0
       - name: "Install Node dependencies"
-        run: npm ci
+        run: npm ci --ignore-scripts
         working-directory: playground
       - name: "Run TypeScript checks"
         run: npm run check

.github/workflows/publish-pypi.yml

@@ -18,8 +18,7 @@ jobs:
     environment:
       name: release
     permissions:
-      # For PyPI's trusted publishing.
-      id-token: write
+      id-token: write # For PyPI's trusted publishing + PEP 740 attestations
     steps:
       - name: "Install uv"
         uses: astral-sh/setup-uv@1e862dfacbd1d6d858c55d9b792c756523627244 # v7.1.4
@@ -28,5 +27,8 @@ jobs:
           pattern: wheels-*
           path: wheels
           merge-multiple: true
+      - uses: astral-sh/attest-action@2c727738cea36d6c97dd85eb133ea0e0e8fe754b # v0.0.4
+        with:
+          paths: wheels/*
       - name: Publish to PyPi
         run: uv publish -v wheels/*

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

@@ -41,7 +41,7 @@ jobs:
           package-manager-cache: false
       - uses: jetli/wasm-bindgen-action@20b33e20595891ab1a0ed73145d8a21fc96e7c29 # v0.2.0
       - name: "Install Node dependencies"
-        run: npm ci
+        run: npm ci --ignore-scripts
         working-directory: playground
       - name: "Run TypeScript checks"
         run: npm run check

.github/workflows/sync_typeshed.yaml

@@ -198,7 +198,7 @@ jobs:
         run: |
           rm "${VENDORED_TYPESHED}/pyproject.toml"
           git commit -am "Remove pyproject.toml file"
-      - uses: Swatinem/rust-cache@f13886b937689c021905a6b90929199931d60db1 # v2.8.1
+      - uses: Swatinem/rust-cache@779680da715d629ac1d338a641029a2f4372abb5 # v2.8.2
       - name: "Install Rust toolchain"
         if: ${{ success() }}
         run: rustup show
@@ -207,12 +207,12 @@ jobs:
         uses: rui314/setup-mold@725a8794d15fc7563f59595bd9556495c0564878 # v1
       - name: "Install cargo nextest"
         if: ${{ success() }}
-        uses: taiki-e/install-action@f79fe7514db78f0a7bdba3cb6dd9c1baa7d046d9 # v2.62.56
+        uses: taiki-e/install-action@3575e532701a5fc614b0c842e4119af4cc5fd16d # v2.62.60
         with:
           tool: cargo-nextest
       - name: "Install cargo insta"
         if: ${{ success() }}
-        uses: taiki-e/install-action@f79fe7514db78f0a7bdba3cb6dd9c1baa7d046d9 # v2.62.56
+        uses: taiki-e/install-action@3575e532701a5fc614b0c842e4119af4cc5fd16d # v2.62.60
         with:
           tool: cargo-insta
       - name: Update snapshots

.github/workflows/ty-ecosystem-analyzer.yaml

@@ -37,7 +37,7 @@ jobs:
         with:
           enable-cache: true # zizmor: ignore[cache-poisoning] acceptable risk for CloudFlare pages artifact
 
-      - uses: Swatinem/rust-cache@f13886b937689c021905a6b90929199931d60db1 # v2.8.1
+      - uses: Swatinem/rust-cache@779680da715d629ac1d338a641029a2f4372abb5 # v2.8.2
         with:
           workspaces: "ruff"
           lookup-only: false # zizmor: ignore[cache-poisoning] acceptable risk for CloudFlare pages artifact

.github/workflows/ty-ecosystem-report.yaml

@@ -33,7 +33,7 @@ jobs:
         with:
           enable-cache: true # zizmor: ignore[cache-poisoning] acceptable risk for CloudFlare pages artifact
 
-      - uses: Swatinem/rust-cache@f13886b937689c021905a6b90929199931d60db1 # v2.8.1
+      - uses: Swatinem/rust-cache@779680da715d629ac1d338a641029a2f4372abb5 # v2.8.2
         with:
           workspaces: "ruff"
           lookup-only: false # zizmor: ignore[cache-poisoning] acceptable risk for CloudFlare pages artifact

.github/workflows/typing_conformance.yaml

@@ -45,7 +45,7 @@ jobs:
           path: typing
           persist-credentials: false
 
-      - uses: Swatinem/rust-cache@f13886b937689c021905a6b90929199931d60db1 # v2.8.1
+      - uses: Swatinem/rust-cache@779680da715d629ac1d338a641029a2f4372abb5 # v2.8.2
         with:
           workspaces: "ruff"
 

Cargo.lock

@@ -1108,7 +1108,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "39cab71617ae0d63f51a36d69f866391735b51691dbda63cf6f96d042b63efeb"
 dependencies = [
  "libc",
- "windows-sys 0.52.0",
+ "windows-sys 0.59.0",
 ]
 
 [[package]]
@@ -1763,7 +1763,7 @@ dependencies = [
  "portable-atomic",
  "portable-atomic-util",
  "serde_core",
- "windows-sys 0.52.0",
+ "windows-sys 0.59.0",
 ]
 
 [[package]]
@@ -3570,7 +3570,7 @@ dependencies = [
  "errno",
  "libc",
  "linux-raw-sys",
- "windows-sys 0.52.0",
+ "windows-sys 0.59.0",
 ]
 
 [[package]]
@@ -3588,7 +3588,7 @@ checksum = "28d3b2b1366ec20994f1fd18c3c594f05c5dd4bc44d8bb0c1c632c8d6829481f"
 [[package]]
 name = "salsa"
 version = "0.24.0"
-source = "git+https://github.com/salsa-rs/salsa.git?rev=17bc55d699565e5a1cb1bd42363b905af2f9f3e7#17bc55d699565e5a1cb1bd42363b905af2f9f3e7"
+source = "git+https://github.com/salsa-rs/salsa.git?rev=59aa1075e837f5deb0d6ffb24b68fedc0f4bc5e0#59aa1075e837f5deb0d6ffb24b68fedc0f4bc5e0"
 dependencies = [
  "boxcar",
  "compact_str",
@@ -3612,12 +3612,12 @@ dependencies = [
 [[package]]
 name = "salsa-macro-rules"
 version = "0.24.0"
-source = "git+https://github.com/salsa-rs/salsa.git?rev=17bc55d699565e5a1cb1bd42363b905af2f9f3e7#17bc55d699565e5a1cb1bd42363b905af2f9f3e7"
+source = "git+https://github.com/salsa-rs/salsa.git?rev=59aa1075e837f5deb0d6ffb24b68fedc0f4bc5e0#59aa1075e837f5deb0d6ffb24b68fedc0f4bc5e0"
 
 [[package]]
 name = "salsa-macros"
 version = "0.24.0"
-source = "git+https://github.com/salsa-rs/salsa.git?rev=17bc55d699565e5a1cb1bd42363b905af2f9f3e7#17bc55d699565e5a1cb1bd42363b905af2f9f3e7"
+source = "git+https://github.com/salsa-rs/salsa.git?rev=59aa1075e837f5deb0d6ffb24b68fedc0f4bc5e0#59aa1075e837f5deb0d6ffb24b68fedc0f4bc5e0"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -3971,7 +3971,7 @@ dependencies = [
  "getrandom 0.3.4",
  "once_cell",
  "rustix",
- "windows-sys 0.52.0",
+ "windows-sys 0.59.0",
 ]
 
 [[package]]
@@ -4216,9 +4216,9 @@ checksum = "df8b2b54733674ad286d16267dcfc7a71ed5c776e4ac7aa3c3e2561f7c637bf2"
 
 [[package]]
 name = "tracing"
-version = "0.1.41"
+version = "0.1.43"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "784e0ac535deb450455cbfa28a6f0df145ea1bb7ae51b821cf5e7927fdcfbdd0"
+checksum = "2d15d90a0b5c19378952d479dc858407149d7bb45a14de0142f6c534b16fc647"
 dependencies = [
  "log",
  "pin-project-lite",
@@ -4228,9 +4228,9 @@ dependencies = [
 
 [[package]]
 name = "tracing-attributes"
-version = "0.1.30"
+version = "0.1.31"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "81383ab64e72a7a8b8e13130c49e3dab29def6d0c7d76a03087b3cf71c5c6903"
+checksum = "7490cfa5ec963746568740651ac6781f701c9c5ea257c58e057f3ba8cf69e8da"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -4239,9 +4239,9 @@ dependencies = [
 
 [[package]]
 name = "tracing-core"
-version = "0.1.34"
+version = "0.1.35"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b9d12581f227e93f094d3af2ae690a574abb8a2b9b7a96e7cfe9647b2b617678"
+checksum = "7a04e24fab5c89c6a36eb8558c9656f30d81de51dfa4d3b45f26b21d61fa0a6c"
 dependencies = [
  "once_cell",
  "valuable",
@@ -4283,9 +4283,9 @@ dependencies = [
 
 [[package]]
 name = "tracing-subscriber"
-version = "0.3.20"
+version = "0.3.22"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "2054a14f5307d601f88daf0553e1cbf472acc4f2c51afab632431cdcd72124d5"
+checksum = "2f30143827ddab0d256fd843b7a66d164e9f271cfa0dde49142c5ca0ca291f1e"
 dependencies = [
  "chrono",
  "matchers",
@@ -5024,7 +5024,7 @@ version = "0.1.11"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "c2a7b1c03c876122aa43f3020e6c3c3ee5c05081c9a00739faf7503aeba10d22"
 dependencies = [
- "windows-sys 0.52.0",
+ "windows-sys 0.59.0",
 ]
 
 [[package]]

Cargo.toml

@@ -146,7 +146,7 @@ regex-automata = { version = "0.4.9" }
 rustc-hash = { version = "2.0.0" }
 rustc-stable-hash = { version = "0.1.2" }
 # When updating salsa, make sure to also update the revision in `fuzz/Cargo.toml`
-salsa = { git = "https://github.com/salsa-rs/salsa.git", rev = "17bc55d699565e5a1cb1bd42363b905af2f9f3e7", default-features = false, features = [
+salsa = { git = "https://github.com/salsa-rs/salsa.git", rev = "59aa1075e837f5deb0d6ffb24b68fedc0f4bc5e0", default-features = false, features = [
     "compact_str",
     "macros",
     "salsa_unstable",

crates/ruff_db/src/diagnostic/mod.rs

@@ -354,6 +354,13 @@ impl Diagnostic {
         Arc::make_mut(&mut self.inner).fix = Some(fix);
     }
 
+    /// If `fix` is `Some`, set the fix for this diagnostic.
+    pub fn set_optional_fix(&mut self, fix: Option<Fix>) {
+        if let Some(fix) = fix {
+            self.set_fix(fix);
+        }
+    }
+
     /// Remove the fix for this diagnostic.
     pub fn remove_fix(&mut self) {
         Arc::make_mut(&mut self.inner).fix = None;

crates/ruff_diagnostics/src/fix.rs

@@ -149,6 +149,10 @@ impl Fix {
         &self.edits
     }
 
+    pub fn into_edits(self) -> Vec<Edit> {
+        self.edits
+    }
+
     /// Return the [`Applicability`] of the [`Fix`].
     pub fn applicability(&self) -> Applicability {
         self.applicability

crates/ruff_linter/resources/test/fixtures/flake8_simplify/SIM222.py

@@ -216,3 +216,15 @@ def get_items_list():
 
 def get_items_set():
     return tuple({item for item in items}) or None  # OK
+
+
+# https://github.com/astral-sh/ruff/issues/21473
+tuple("") or True  # SIM222
+tuple(t"") or True  # OK
+tuple(0) or True  # OK
+tuple(1) or True  # OK
+tuple(False) or True  # OK
+tuple(None) or True  # OK
+tuple(...) or True  # OK
+tuple(lambda x: x) or True  # OK
+tuple(x for x in range(0)) or True  # OK

crates/ruff_linter/resources/test/fixtures/flake8_simplify/SIM223.py

@@ -157,3 +157,15 @@ print(f"{1}{''}" and "bar")
 
 # https://github.com/astral-sh/ruff/issues/7127
 def f(a: "'' and 'b'"): ...
+
+
+# https://github.com/astral-sh/ruff/issues/21473
+tuple("") and False  # SIM223
+tuple(t"") and False  # OK
+tuple(0) and False  # OK
+tuple(1) and False  # OK
+tuple(False) and False  # OK
+tuple(None) and False  # OK
+tuple(...) and False  # OK
+tuple(lambda x: x) and False  # OK
+tuple(x for x in range(0)) and False  # OK

crates/ruff_linter/src/rules/flake8_simplify/snapshots/ruff_linter__rules__flake8_simplify__tests__SIM222_SIM222.py.snap

@@ -1144,3 +1144,23 @@ help: Replace with `(i for i in range(1))`
 208 | # https://github.com/astral-sh/ruff/issues/21136
 209 | def get_items():
 note: This is an unsafe fix and may change runtime behavior
+
+SIM222 [*] Use `True` instead of `... or True`
+   --> SIM222.py:222:1
+    |
+221 | # https://github.com/astral-sh/ruff/issues/21473
+222 | tuple("") or True  # SIM222
+    | ^^^^^^^^^^^^^^^^^
+223 | tuple(t"") or True  # OK
+224 | tuple(0) or True  # OK
+    |
+help: Replace with `True`
+219 | 
+220 | 
+221 | # https://github.com/astral-sh/ruff/issues/21473
+    - tuple("") or True  # SIM222
+222 + True  # SIM222
+223 | tuple(t"") or True  # OK
+224 | tuple(0) or True  # OK
+225 | tuple(1) or True  # OK
+note: This is an unsafe fix and may change runtime behavior

crates/ruff_linter/src/rules/flake8_simplify/snapshots/ruff_linter__rules__flake8_simplify__tests__SIM223_SIM223.py.snap

@@ -1025,3 +1025,23 @@ help: Replace with `f"{''}{''}"`
 156 | 
 157 | 
 note: This is an unsafe fix and may change runtime behavior
+
+SIM223 [*] Use `tuple("")` instead of `tuple("") and ...`
+   --> SIM223.py:163:1
+    |
+162 | # https://github.com/astral-sh/ruff/issues/21473
+163 | tuple("") and False  # SIM223
+    | ^^^^^^^^^^^^^^^^^^^
+164 | tuple(t"") and False  # OK
+165 | tuple(0) and False  # OK
+    |
+help: Replace with `tuple("")`
+160 | 
+161 | 
+162 | # https://github.com/astral-sh/ruff/issues/21473
+    - tuple("") and False  # SIM223
+163 + tuple("")  # SIM223
+164 | tuple(t"") and False  # OK
+165 | tuple(0) and False  # OK
+166 | tuple(1) and False  # OK
+note: This is an unsafe fix and may change runtime behavior

crates/ruff_linter/src/rules/flake8_use_pathlib/helpers.rs

@@ -57,7 +57,7 @@ pub(crate) fn check_os_pathlib_single_arg_calls(
     fn_argument: &str,
     fix_enabled: bool,
     violation: impl Violation,
-    applicability: Option<Applicability>,
+    applicability: Applicability,
 ) {
     if call.arguments.len() != 1 {
         return;
@@ -91,18 +91,14 @@ pub(crate) fn check_os_pathlib_single_arg_calls(
 
         let edit = Edit::range_replacement(replacement, range);
 
-        let fix = match applicability {
-            Some(Applicability::Unsafe) => Fix::unsafe_edits(edit, [import_edit]),
-            _ => {
-                let applicability = if checker.comment_ranges().intersects(range) {
-                    Applicability::Unsafe
-                } else {
-                    Applicability::Safe
-                };
-                Fix::applicable_edits(edit, [import_edit], applicability)
-            }
+        let applicability = match applicability {
+            Applicability::DisplayOnly => Applicability::DisplayOnly,
+            _ if checker.comment_ranges().intersects(range) => Applicability::Unsafe,
+            _ => applicability,
         };
 
+        let fix = Fix::applicable_edits(edit, [import_edit], applicability);
+
         Ok(fix)
     });
 }
@@ -138,6 +134,7 @@ pub(crate) fn is_file_descriptor(expr: &Expr, semantic: &SemanticModel) -> bool
     typing::is_int(binding, semantic)
 }
 
+#[expect(clippy::too_many_arguments)]
 pub(crate) fn check_os_pathlib_two_arg_calls(
     checker: &Checker,
     call: &ExprCall,
@@ -146,6 +143,7 @@ pub(crate) fn check_os_pathlib_two_arg_calls(
     second_arg: &str,
     fix_enabled: bool,
     violation: impl Violation,
+    applicability: Applicability,
 ) {
     let range = call.range();
     let mut diagnostic = checker.report_diagnostic(violation, call.func.range());
@@ -174,10 +172,10 @@ pub(crate) fn check_os_pathlib_two_arg_calls(
                 format!("{binding}({path_code}).{attr}({second_code})")
             };
 
-            let applicability = if checker.comment_ranges().intersects(range) {
-                Applicability::Unsafe
-            } else {
-                Applicability::Safe
+            let applicability = match applicability {
+                Applicability::DisplayOnly => Applicability::DisplayOnly,
+                _ if checker.comment_ranges().intersects(range) => Applicability::Unsafe,
+                _ => applicability,
             };
 
             Ok(Fix::applicable_edits(
@@ -209,3 +207,9 @@ pub(crate) fn is_argument_non_default(arguments: &Arguments, name: &str, positio
         .find_argument_value(name, position)
         .is_some_and(|expr| !expr.is_none_literal_expr())
 }
+
+/// Returns `true` if the given call is a top-level expression in its statement.
+/// This means the call's return value is not used, so return type changes don't matter.
+pub(crate) fn is_top_level_expression_call(checker: &Checker) -> bool {
+    checker.semantic().current_expression_parent().is_none()
+}

crates/ruff_linter/src/rules/flake8_use_pathlib/rules/os_getcwd.rs

@@ -1,12 +1,14 @@
-use crate::checkers::ast::Checker;
-use crate::importer::ImportRequest;
-use crate::preview::is_fix_os_getcwd_enabled;
-use crate::{FixAvailability, Violation};
 use ruff_diagnostics::{Applicability, Edit, Fix};
 use ruff_macros::{ViolationMetadata, derive_message_formats};
 use ruff_python_ast::ExprCall;
 use ruff_text_size::Ranged;
 
+use crate::checkers::ast::Checker;
+use crate::importer::ImportRequest;
+use crate::preview::is_fix_os_getcwd_enabled;
+use crate::rules::flake8_use_pathlib::helpers::is_top_level_expression_call;
+use crate::{FixAvailability, Violation};
+
 /// ## What it does
 /// Checks for uses of `os.getcwd` and `os.getcwdb`.
 ///
@@ -37,6 +39,8 @@ use ruff_text_size::Ranged;
 ///
 /// ## Fix Safety
 /// This rule's fix is marked as unsafe if the replacement would remove comments attached to the original expression.
+/// Additionally, the fix is marked as unsafe when the return value is used because the type changes
+/// from `str` or `bytes` to a `Path` object.
 ///
 /// ## References
 /// - [Python documentation: `Path.cwd`](https://docs.python.org/3/library/pathlib.html#pathlib.Path.cwd)
@@ -83,7 +87,10 @@ pub(crate) fn os_getcwd(checker: &Checker, call: &ExprCall, segments: &[&str]) {
                 checker.semantic(),
             )?;
 
-            let applicability = if checker.comment_ranges().intersects(range) {
+            // Unsafe when the fix would delete comments or change a used return value
+            let applicability = if checker.comment_ranges().intersects(range)
+                || !is_top_level_expression_call(checker)
+            {
                 Applicability::Unsafe
             } else {
                 Applicability::Safe

crates/ruff_linter/src/rules/flake8_use_pathlib/rules/os_path_abspath.rs

@@ -45,6 +45,10 @@ use crate::{FixAvailability, Violation};
 /// behaviors is required, there's no existing `pathlib` alternative. See CPython issue
 /// [#69200](https://github.com/python/cpython/issues/69200).
 ///
+/// Additionally, the fix is marked as unsafe because `os.path.abspath()` returns `str` or `bytes` (`AnyStr`),
+/// while `Path.resolve()` returns a `Path` object. This change in return type can break code that uses
+/// the return value.
+///
 /// ## References
 /// - [Python documentation: `Path.resolve`](https://docs.python.org/3/library/pathlib.html#pathlib.Path.resolve)
 /// - [Python documentation: `os.path.abspath`](https://docs.python.org/3/library/os.path.html#os.path.abspath)
@@ -85,6 +89,6 @@ pub(crate) fn os_path_abspath(checker: &Checker, call: &ExprCall, segments: &[&s
         "path",
         is_fix_os_path_abspath_enabled(checker.settings()),
         OsPathAbspath,
-        Some(Applicability::Unsafe),
+        Applicability::Unsafe,
     );
 }

crates/ruff_linter/src/rules/flake8_use_pathlib/rules/os_path_basename.rs

@@ -82,6 +82,6 @@ pub(crate) fn os_path_basename(checker: &Checker, call: &ExprCall, segments: &[&
         "p",
         is_fix_os_path_basename_enabled(checker.settings()),
         OsPathBasename,
-        Some(Applicability::Unsafe),
+        Applicability::Unsafe,
     );
 }

crates/ruff_linter/src/rules/flake8_use_pathlib/rules/os_path_dirname.rs

@@ -42,6 +42,10 @@ use crate::{FixAvailability, Violation};
 /// As a result, code relying on the exact string returned by `os.path.dirname`
 /// may behave differently after the fix.
 ///
+/// Additionally, the fix is marked as unsafe because `os.path.dirname()` returns `str` or `bytes` (`AnyStr`),
+/// while `Path.parent` returns a `Path` object. This change in return type can break code that uses
+/// the return value.
+///
 /// ## Known issues
 /// While using `pathlib` can improve the readability and type safety of your code,
 /// it can be less performant than the lower-level alternatives that work directly with strings,
@@ -82,6 +86,6 @@ pub(crate) fn os_path_dirname(checker: &Checker, call: &ExprCall, segments: &[&s
         "p",
         is_fix_os_path_dirname_enabled(checker.settings()),
         OsPathDirname,
-        Some(Applicability::Unsafe),
+        Applicability::Unsafe,
     );
 }

crates/ruff_linter/src/rules/flake8_use_pathlib/rules/os_path_exists.rs

@@ -1,3 +1,4 @@
+use ruff_diagnostics::Applicability;
 use ruff_macros::{ViolationMetadata, derive_message_formats};
 use ruff_python_ast::ExprCall;
 
@@ -72,6 +73,6 @@ pub(crate) fn os_path_exists(checker: &Checker, call: &ExprCall, segments: &[&st
         "path",
         is_fix_os_path_exists_enabled(checker.settings()),
         OsPathExists,
-        None,
+        Applicability::Safe,
     );
 }

crates/ruff_linter/src/rules/flake8_use_pathlib/rules/os_path_expanduser.rs

@@ -41,6 +41,10 @@ use crate::{FixAvailability, Violation};
 /// directory can't be resolved: `os.path.expanduser` returns the
 /// input unchanged, while `Path.expanduser` raises `RuntimeError`.
 ///
+/// Additionally, the fix is marked as unsafe because `os.path.expanduser()` returns `str` or `bytes` (`AnyStr`),
+/// while `Path.expanduser()` returns a `Path` object. This change in return type can break code that uses
+/// the return value.
+///
 /// ## References
 /// - [Python documentation: `Path.expanduser`](https://docs.python.org/3/library/pathlib.html#pathlib.Path.expanduser)
 /// - [Python documentation: `os.path.expanduser`](https://docs.python.org/3/library/os.path.html#os.path.expanduser)
@@ -76,6 +80,6 @@ pub(crate) fn os_path_expanduser(checker: &Checker, call: &ExprCall, segments: &
         "path",
         is_fix_os_path_expanduser_enabled(checker.settings()),
         OsPathExpanduser,
-        Some(Applicability::Unsafe),
+        Applicability::Unsafe,
     );
 }

crates/ruff_linter/src/rules/flake8_use_pathlib/rules/os_path_getatime.rs

@@ -1,3 +1,4 @@
+use ruff_diagnostics::Applicability;
 use ruff_macros::{ViolationMetadata, derive_message_formats};
 use ruff_python_ast::ExprCall;
 
@@ -75,6 +76,6 @@ pub(crate) fn os_path_getatime(checker: &Checker, call: &ExprCall, segments: &[&
         "filename",
         is_fix_os_path_getatime_enabled(checker.settings()),
         OsPathGetatime,
-        None,
+        Applicability::Safe,
     );
 }

crates/ruff_linter/src/rules/flake8_use_pathlib/rules/os_path_getctime.rs

@@ -1,3 +1,4 @@
+use ruff_diagnostics::Applicability;
 use ruff_macros::{ViolationMetadata, derive_message_formats};
 use ruff_python_ast::ExprCall;
 
@@ -76,6 +77,6 @@ pub(crate) fn os_path_getctime(checker: &Checker, call: &ExprCall, segments: &[&
         "filename",
         is_fix_os_path_getctime_enabled(checker.settings()),
         OsPathGetctime,
-        None,
+        Applicability::Safe,
     );
 }

crates/ruff_linter/src/rules/flake8_use_pathlib/rules/os_path_getmtime.rs

@@ -1,3 +1,4 @@
+use ruff_diagnostics::Applicability;
 use ruff_macros::{ViolationMetadata, derive_message_formats};
 use ruff_python_ast::ExprCall;
 
@@ -76,6 +77,6 @@ pub(crate) fn os_path_getmtime(checker: &Checker, call: &ExprCall, segments: &[&
         "filename",
         is_fix_os_path_getmtime_enabled(checker.settings()),
         OsPathGetmtime,
-        None,
+        Applicability::Safe,
     );
 }

crates/ruff_linter/src/rules/flake8_use_pathlib/rules/os_path_getsize.rs

@@ -1,3 +1,4 @@
+use ruff_diagnostics::Applicability;
 use ruff_macros::{ViolationMetadata, derive_message_formats};
 use ruff_python_ast::ExprCall;
 
@@ -76,6 +77,6 @@ pub(crate) fn os_path_getsize(checker: &Checker, call: &ExprCall, segments: &[&s
         "filename",
         is_fix_os_path_getsize_enabled(checker.settings()),
         OsPathGetsize,
-        None,
+        Applicability::Safe,
     );
 }

crates/ruff_linter/src/rules/flake8_use_pathlib/rules/os_path_isabs.rs

@@ -1,3 +1,4 @@
+use ruff_diagnostics::Applicability;
 use ruff_macros::{ViolationMetadata, derive_message_formats};
 use ruff_python_ast::ExprCall;
 
@@ -71,6 +72,6 @@ pub(crate) fn os_path_isabs(checker: &Checker, call: &ExprCall, segments: &[&str
         "s",
         is_fix_os_path_isabs_enabled(checker.settings()),
         OsPathIsabs,
-        None,
+        Applicability::Safe,
     );
 }

crates/ruff_linter/src/rules/flake8_use_pathlib/rules/os_path_isdir.rs

@@ -1,3 +1,4 @@
+use ruff_diagnostics::Applicability;
 use ruff_macros::{ViolationMetadata, derive_message_formats};
 use ruff_python_ast::ExprCall;
 
@@ -73,6 +74,6 @@ pub(crate) fn os_path_isdir(checker: &Checker, call: &ExprCall, segments: &[&str
         "s",
         is_fix_os_path_isdir_enabled(checker.settings()),
         OsPathIsdir,
-        None,
+        Applicability::Safe,
     );
 }

crates/ruff_linter/src/rules/flake8_use_pathlib/rules/os_path_isfile.rs

@@ -1,3 +1,4 @@
+use ruff_diagnostics::Applicability;
 use ruff_macros::{ViolationMetadata, derive_message_formats};
 use ruff_python_ast::ExprCall;
 
@@ -73,6 +74,6 @@ pub(crate) fn os_path_isfile(checker: &Checker, call: &ExprCall, segments: &[&st
         "path",
         is_fix_os_path_isfile_enabled(checker.settings()),
         OsPathIsfile,
-        None,
+        Applicability::Safe,
     );
 }

crates/ruff_linter/src/rules/flake8_use_pathlib/rules/os_path_islink.rs

@@ -1,3 +1,4 @@
+use ruff_diagnostics::Applicability;
 use ruff_macros::{ViolationMetadata, derive_message_formats};
 use ruff_python_ast::ExprCall;
 
@@ -73,6 +74,6 @@ pub(crate) fn os_path_islink(checker: &Checker, call: &ExprCall, segments: &[&st
         "path",
         is_fix_os_path_islink_enabled(checker.settings()),
         OsPathIslink,
-        None,
+        Applicability::Safe,
     );
 }

crates/ruff_linter/src/rules/flake8_use_pathlib/rules/os_path_samefile.rs

@@ -1,11 +1,13 @@
+use ruff_diagnostics::Applicability;
+use ruff_macros::{ViolationMetadata, derive_message_formats};
+use ruff_python_ast::ExprCall;
+
 use crate::checkers::ast::Checker;
 use crate::preview::is_fix_os_path_samefile_enabled;
 use crate::rules::flake8_use_pathlib::helpers::{
     check_os_pathlib_two_arg_calls, has_unknown_keywords_or_starred_expr,
 };
 use crate::{FixAvailability, Violation};
-use ruff_macros::{ViolationMetadata, derive_message_formats};
-use ruff_python_ast::ExprCall;
 
 /// ## What it does
 /// Checks for uses of `os.path.samefile`.
@@ -79,5 +81,6 @@ pub(crate) fn os_path_samefile(checker: &Checker, call: &ExprCall, segments: &[&
         "f2",
         fix_enabled,
         OsPathSamefile,
+        Applicability::Safe,
     );
 }

crates/ruff_linter/src/rules/flake8_use_pathlib/rules/os_readlink.rs

@@ -1,3 +1,4 @@
+use ruff_diagnostics::Applicability;
 use ruff_macros::{ViolationMetadata, derive_message_formats};
 use ruff_python_ast::{ExprCall, PythonVersion};
 
@@ -5,6 +6,7 @@ use crate::checkers::ast::Checker;
 use crate::preview::is_fix_os_readlink_enabled;
 use crate::rules::flake8_use_pathlib::helpers::{
     check_os_pathlib_single_arg_calls, is_keyword_only_argument_non_default,
+    is_top_level_expression_call,
 };
 use crate::{FixAvailability, Violation};
 
@@ -38,6 +40,8 @@ use crate::{FixAvailability, Violation};
 ///
 /// ## Fix Safety
 /// This rule's fix is marked as unsafe if the replacement would remove comments attached to the original expression.
+/// Additionally, the fix is marked as unsafe when the return value is used because the type changes
+/// from `str` or `bytes` (`AnyStr`) to a `Path` object.
 ///
 /// ## References
 /// - [Python documentation: `Path.readlink`](https://docs.python.org/3/library/pathlib.html#pathlib.Path.readline)
@@ -82,6 +86,13 @@ pub(crate) fn os_readlink(checker: &Checker, call: &ExprCall, segments: &[&str])
         return;
     }
 
+    let applicability = if !is_top_level_expression_call(checker) {
+        // Unsafe because the return type changes (str/bytes -> Path)
+        Applicability::Unsafe
+    } else {
+        Applicability::Safe
+    };
+
     check_os_pathlib_single_arg_calls(
         checker,
         call,
@@ -89,6 +100,6 @@ pub(crate) fn os_readlink(checker: &Checker, call: &ExprCall, segments: &[&str])
         "path",
         is_fix_os_readlink_enabled(checker.settings()),
         OsReadlink,
-        None,
+        applicability,
     );
 }

crates/ruff_linter/src/rules/flake8_use_pathlib/rules/os_remove.rs

@@ -1,3 +1,4 @@
+use ruff_diagnostics::Applicability;
 use ruff_macros::{ViolationMetadata, derive_message_formats};
 use ruff_python_ast::ExprCall;
 
@@ -84,6 +85,6 @@ pub(crate) fn os_remove(checker: &Checker, call: &ExprCall, segments: &[&str]) {
         "path",
         is_fix_os_remove_enabled(checker.settings()),
         OsRemove,
-        None,
+        Applicability::Safe,
     );
 }

crates/ruff_linter/src/rules/flake8_use_pathlib/rules/os_rename.rs

@@ -1,12 +1,14 @@
+use ruff_diagnostics::Applicability;
+use ruff_macros::{ViolationMetadata, derive_message_formats};
+use ruff_python_ast::ExprCall;
+
 use crate::checkers::ast::Checker;
 use crate::preview::is_fix_os_rename_enabled;
 use crate::rules::flake8_use_pathlib::helpers::{
     check_os_pathlib_two_arg_calls, has_unknown_keywords_or_starred_expr,
-    is_keyword_only_argument_non_default,
+    is_keyword_only_argument_non_default, is_top_level_expression_call,
 };
 use crate::{FixAvailability, Violation};
-use ruff_macros::{ViolationMetadata, derive_message_formats};
-use ruff_python_ast::ExprCall;
 
 /// ## What it does
 /// Checks for uses of `os.rename`.
@@ -38,6 +40,8 @@ use ruff_python_ast::ExprCall;
 ///
 /// ## Fix Safety
 /// This rule's fix is marked as unsafe if the replacement would remove comments attached to the original expression.
+/// Additionally, the fix is marked as unsafe when the return value is used because the type changes
+/// from `None` to a `Path` object.
 ///
 /// ## References
 /// - [Python documentation: `Path.rename`](https://docs.python.org/3/library/pathlib.html#pathlib.Path.rename)
@@ -87,5 +91,22 @@ pub(crate) fn os_rename(checker: &Checker, call: &ExprCall, segments: &[&str]) {
             &["src", "dst", "src_dir_fd", "dst_dir_fd"],
         );
 
-    check_os_pathlib_two_arg_calls(checker, call, "rename", "src", "dst", fix_enabled, OsRename);
+    // Unsafe when the fix would delete comments or change a used return value
+    let applicability = if !is_top_level_expression_call(checker) {
+        // Unsafe because the return type changes (None -> Path)
+        Applicability::Unsafe
+    } else {
+        Applicability::Safe
+    };
+
+    check_os_pathlib_two_arg_calls(
+        checker,
+        call,
+        "rename",
+        "src",
+        "dst",
+        fix_enabled,
+        OsRename,
+        applicability,
+    );
 }

crates/ruff_linter/src/rules/flake8_use_pathlib/rules/os_replace.rs

@@ -1,12 +1,14 @@
+use ruff_diagnostics::Applicability;
+use ruff_macros::{ViolationMetadata, derive_message_formats};
+use ruff_python_ast::ExprCall;
+
 use crate::checkers::ast::Checker;
 use crate::preview::is_fix_os_replace_enabled;
 use crate::rules::flake8_use_pathlib::helpers::{
     check_os_pathlib_two_arg_calls, has_unknown_keywords_or_starred_expr,
-    is_keyword_only_argument_non_default,
+    is_keyword_only_argument_non_default, is_top_level_expression_call,
 };
 use crate::{FixAvailability, Violation};
-use ruff_macros::{ViolationMetadata, derive_message_formats};
-use ruff_python_ast::ExprCall;
 
 /// ## What it does
 /// Checks for uses of `os.replace`.
@@ -41,6 +43,8 @@ use ruff_python_ast::ExprCall;
 ///
 /// ## Fix Safety
 /// This rule's fix is marked as unsafe if the replacement would remove comments attached to the original expression.
+/// Additionally, the fix is marked as unsafe when the return value is used because the type changes
+/// from `None` to a `Path` object.
 ///
 /// ## References
 /// - [Python documentation: `Path.replace`](https://docs.python.org/3/library/pathlib.html#pathlib.Path.replace)
@@ -90,6 +94,14 @@ pub(crate) fn os_replace(checker: &Checker, call: &ExprCall, segments: &[&str])
             &["src", "dst", "src_dir_fd", "dst_dir_fd"],
         );
 
+    // Unsafe when the fix would delete comments or change a used return value
+    let applicability = if !is_top_level_expression_call(checker) {
+        // Unsafe because the return type changes (None -> Path)
+        Applicability::Unsafe
+    } else {
+        Applicability::Safe
+    };
+
     check_os_pathlib_two_arg_calls(
         checker,
         call,
@@ -98,5 +110,6 @@ pub(crate) fn os_replace(checker: &Checker, call: &ExprCall, segments: &[&str])
         "dst",
         fix_enabled,
         OsReplace,
+        applicability,
     );
 }

crates/ruff_linter/src/rules/flake8_use_pathlib/rules/os_rmdir.rs

@@ -1,3 +1,4 @@
+use ruff_diagnostics::Applicability;
 use ruff_macros::{ViolationMetadata, derive_message_formats};
 use ruff_python_ast::ExprCall;
 
@@ -84,6 +85,6 @@ pub(crate) fn os_rmdir(checker: &Checker, call: &ExprCall, segments: &[&str]) {
         "path",
         is_fix_os_rmdir_enabled(checker.settings()),
         OsRmdir,
-        None,
+        Applicability::Safe,
     );
 }

crates/ruff_linter/src/rules/flake8_use_pathlib/rules/os_unlink.rs

@@ -1,3 +1,4 @@
+use ruff_diagnostics::Applicability;
 use ruff_macros::{ViolationMetadata, derive_message_formats};
 use ruff_python_ast::ExprCall;
 
@@ -84,6 +85,6 @@ pub(crate) fn os_unlink(checker: &Checker, call: &ExprCall, segments: &[&str]) {
         "path",
         is_fix_os_unlink_enabled(checker.settings()),
         OsUnlink,
-        None,
+        Applicability::Safe,
     );
 }

crates/ruff_python_ast/src/helpers.rs

@@ -1322,14 +1322,22 @@ impl Truthiness {
                             && arguments.keywords.is_empty()
                         {
                             // Ex) `list([1, 2, 3])`
-                            // For tuple(generator), we can't determine statically if the result will
-                            // be empty or not, so return Unknown. The generator itself is truthy, but
-                            // tuple(empty_generator) is falsy. ListComp and SetComp are handled by
-                            // recursing into Self::from_expr below, which returns Unknown for them.
-                            if argument.is_generator_expr() {
-                                Self::Unknown
-                            } else {
-                                Self::from_expr(argument, is_builtin)
+                            match argument {
+                                // Return Unknown for types with definite truthiness that might
+                                // result in empty iterables (t-strings and generators) or will
+                                // raise a type error (non-iterable types like numbers, booleans,
+                                // None, etc.).
+                                Expr::NumberLiteral(_)
+                                | Expr::BooleanLiteral(_)
+                                | Expr::NoneLiteral(_)
+                                | Expr::EllipsisLiteral(_)
+                                | Expr::TString(_)
+                                | Expr::Lambda(_)
+                                | Expr::Generator(_) => Self::Unknown,
+                                // Recurse for all other types - collections, comprehensions, variables, etc.
+                                // StringLiteral, FString, and BytesLiteral recurse because Self::from_expr
+                                // correctly handles their truthiness (checking if empty or not).
+                                _ => Self::from_expr(argument, is_builtin),
                             }
                         } else {
                             Self::Unknown

crates/ruff_python_formatter/CONTRIBUTING.md

@@ -74,7 +74,7 @@ def f():  # a
 The other option is to use the playground (also check the playground README):
 
 ```shell
-cd playground && npm install && npm run dev:wasm && npm run dev
+cd playground && npm ci --ignore-scripts && npm run dev:wasm && npm run dev
 ```
 
 Run`npm run dev:wasm` and reload the page in the browser to refresh.

crates/ty/docs/rules.md

@@ -39,7 +39,7 @@ def test(): -> "int":
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20call-non-callable" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L134" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L135" target="_blank">View source</a>
 </small>
 
 
@@ -63,7 +63,7 @@ Calling a non-callable object will raise a `TypeError` at runtime.
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20conflicting-argument-forms" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L178" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L179" target="_blank">View source</a>
 </small>
 
 
@@ -95,7 +95,7 @@ f(int)  # error
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20conflicting-declarations" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L204" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L205" target="_blank">View source</a>
 </small>
 
 
@@ -126,7 +126,7 @@ a = 1
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20conflicting-metaclass" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L229" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L230" target="_blank">View source</a>
 </small>
 
 
@@ -158,7 +158,7 @@ class C(A, B): ...
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20cyclic-class-definition" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L255" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L256" target="_blank">View source</a>
 </small>
 
 
@@ -190,7 +190,7 @@ class B(A): ...
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Preview (since <a href="https://github.com/astral-sh/ty/releases/tag/1.0.0">1.0.0</a>) ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20cyclic-type-alias-definition" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L281" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L282" target="_blank">View source</a>
 </small>
 
 
@@ -218,7 +218,7 @@ type B = A
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20duplicate-base" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L342" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L343" target="_blank">View source</a>
 </small>
 
 
@@ -245,7 +245,7 @@ class B(A, A): ...
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.12">0.0.1-alpha.12</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20duplicate-kw-only" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L363" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L364" target="_blank">View source</a>
 </small>
 
 
@@ -357,7 +357,7 @@ def test(): -> "Literal[5]":
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20inconsistent-mro" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L567" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L590" target="_blank">View source</a>
 </small>
 
 
@@ -387,7 +387,7 @@ class C(A, B): ...
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20index-out-of-bounds" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L591" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L614" target="_blank">View source</a>
 </small>
 
 
@@ -413,7 +413,7 @@ t[3]  # IndexError: tuple index out of range
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.12">0.0.1-alpha.12</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20instance-layout-conflict" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L395" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L396" target="_blank">View source</a>
 </small>
 
 
@@ -502,7 +502,7 @@ an atypical memory layout.
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-argument-type" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L645" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L668" target="_blank">View source</a>
 </small>
 
 
@@ -529,7 +529,7 @@ func("foo")  # error: [invalid-argument-type]
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-assignment" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L685" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L708" target="_blank">View source</a>
 </small>
 
 
@@ -557,7 +557,7 @@ a: int = ''
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-attribute-access" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1948" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1998" target="_blank">View source</a>
 </small>
 
 
@@ -591,7 +591,7 @@ C.instance_var = 3  # error: Cannot assign to instance variable
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.19">0.0.1-alpha.19</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-await" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L707" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L730" target="_blank">View source</a>
 </small>
 
 
@@ -627,7 +627,7 @@ asyncio.run(main())
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-base" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L737" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L760" target="_blank">View source</a>
 </small>
 
 
@@ -651,7 +651,7 @@ class A(42): ...  # error: [invalid-base]
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-context-manager" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L788" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L811" target="_blank">View source</a>
 </small>
 
 
@@ -678,7 +678,7 @@ with 1:
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-declaration" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L809" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L832" target="_blank">View source</a>
 </small>
 
 
@@ -707,7 +707,7 @@ a: str
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-exception-caught" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L832" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L855" target="_blank">View source</a>
 </small>
 
 
@@ -751,7 +751,7 @@ except ZeroDivisionError:
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.28">0.0.1-alpha.28</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-explicit-override" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1645" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1668" target="_blank">View source</a>
 </small>
 
 
@@ -793,7 +793,7 @@ class D(A):
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-generic-class" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L868" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L891" target="_blank">View source</a>
 </small>
 
 
@@ -826,7 +826,7 @@ class C[U](Generic[T]): ...
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.17">0.0.1-alpha.17</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-key" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L612" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L635" target="_blank">View source</a>
 </small>
 
 
@@ -865,7 +865,7 @@ carol = Person(name="Carol", age=25)  # typo!
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-legacy-type-variable" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L894" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L917" target="_blank">View source</a>
 </small>
 
 
@@ -900,7 +900,7 @@ def f(t: TypeVar("U")): ...
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-metaclass" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L991" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1014" target="_blank">View source</a>
 </small>
 
 
@@ -934,7 +934,7 @@ class B(metaclass=f): ...
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.20">0.0.1-alpha.20</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-method-override" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L2076" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L2126" target="_blank">View source</a>
 </small>
 
 
@@ -1041,7 +1041,7 @@ Correct use of `@override` is enforced by ty's `invalid-explicit-override` rule.
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.19">0.0.1-alpha.19</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-named-tuple" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L541" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L542" target="_blank">View source</a>
 </small>
 
 
@@ -1052,7 +1052,8 @@ Checks for invalidly defined `NamedTuple` classes.
 **Why is this bad?**
 
 An invalidly defined `NamedTuple` class may lead to the type checker
-drawing incorrect conclusions. It may also lead to `TypeError`s at runtime.
+drawing incorrect conclusions. It may also lead to `TypeError`s or
+`AttributeError`s at runtime.
 
 **Examples**
 
@@ -1067,13 +1068,34 @@ in a class's bases list.
 TypeError: can only inherit from a NamedTuple type and Generic
 ```
 
+Further, `NamedTuple` field names cannot start with an underscore:
+
+```pycon
+>>> from typing import NamedTuple
+>>> class Foo(NamedTuple):
+...     _bar: int
+ValueError: Field names cannot start with an underscore: '_bar'
+```
+
+`NamedTuple` classes also have certain synthesized attributes (like `_asdict`, `_make`,
+`_replace`, etc.) that cannot be overwritten. Attempting to assign to these attributes
+without a type annotation will raise an `AttributeError` at runtime.
+
+```pycon
+>>> from typing import NamedTuple
+>>> class Foo(NamedTuple):
+...     x: int
+...     _asdict = 42
+AttributeError: Cannot overwrite NamedTuple attribute _asdict
+```
+
 ## `invalid-newtype`
 
 <small>
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Preview (since <a href="https://github.com/astral-sh/ty/releases/tag/1.0.0">1.0.0</a>) ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-newtype" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L967" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L990" target="_blank">View source</a>
 </small>
 
 
@@ -1103,7 +1125,7 @@ Baz = NewType("Baz", int | str)  # error: invalid base for `typing.NewType`
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-overload" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1018" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1041" target="_blank">View source</a>
 </small>
 
 
@@ -1153,7 +1175,7 @@ def foo(x: int) -> int: ...
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-parameter-default" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1117" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1140" target="_blank">View source</a>
 </small>
 
 
@@ -1179,7 +1201,7 @@ def f(a: int = ''): ...
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-paramspec" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L922" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L945" target="_blank">View source</a>
 </small>
 
 
@@ -1210,7 +1232,7 @@ P2 = ParamSpec("S2")  # error: ParamSpec name must match the variable it's assig
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-protocol" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L477" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L478" target="_blank">View source</a>
 </small>
 
 
@@ -1244,7 +1266,7 @@ TypeError: Protocols can only inherit from other protocols, got <class 'int'>
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-raise" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1137" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1160" target="_blank">View source</a>
 </small>
 
 
@@ -1293,7 +1315,7 @@ def g():
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-return-type" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L666" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L689" target="_blank">View source</a>
 </small>
 
 
@@ -1318,7 +1340,7 @@ def func() -> int:
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-super-argument" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1180" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1203" target="_blank">View source</a>
 </small>
 
 
@@ -1376,7 +1398,7 @@ TODO #14889
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.6">0.0.1-alpha.6</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-type-alias-type" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L946" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L969" target="_blank">View source</a>
 </small>
 
 
@@ -1403,7 +1425,7 @@ NewAlias = TypeAliasType(get_name(), int)        # error: TypeAliasType name mus
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.29">0.0.1-alpha.29</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-type-arguments" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1412" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1435" target="_blank">View source</a>
 </small>
 
 
@@ -1450,7 +1472,7 @@ Bar[int]  # error: too few arguments
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-type-checking-constant" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1219" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1242" target="_blank">View source</a>
 </small>
 
 
@@ -1480,7 +1502,7 @@ TYPE_CHECKING = ''
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-type-form" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1243" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1266" target="_blank">View source</a>
 </small>
 
 
@@ -1510,7 +1532,7 @@ b: Annotated[int]  # `Annotated` expects at least two arguments
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.11">0.0.1-alpha.11</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-type-guard-call" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1295" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1318" target="_blank">View source</a>
 </small>
 
 
@@ -1544,7 +1566,7 @@ f(10)  # Error
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.11">0.0.1-alpha.11</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-type-guard-definition" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1267" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1290" target="_blank">View source</a>
 </small>
 
 
@@ -1578,7 +1600,7 @@ class C:
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-type-variable-constraints" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1323" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1346" target="_blank">View source</a>
 </small>
 
 
@@ -1613,7 +1635,7 @@ T = TypeVar('T', bound=str)  # valid bound TypeVar
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20missing-argument" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1352" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1375" target="_blank">View source</a>
 </small>
 
 
@@ -1638,7 +1660,7 @@ func()  # TypeError: func() missing 1 required positional argument: 'x'
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.20">0.0.1-alpha.20</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20missing-typed-dict-key" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L2049" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L2099" target="_blank">View source</a>
 </small>
 
 
@@ -1671,7 +1693,7 @@ alice["age"]  # KeyError
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20no-matching-overload" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1371" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1394" target="_blank">View source</a>
 </small>
 
 
@@ -1700,7 +1722,7 @@ func("string")  # error: [no-matching-overload]
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20non-subscriptable" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1394" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1417" target="_blank">View source</a>
 </small>
 
 
@@ -1724,7 +1746,7 @@ Subscripting an object that does not support it will raise a `TypeError` at runt
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20not-iterable" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1453" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1476" target="_blank">View source</a>
 </small>
 
 
@@ -1750,7 +1772,7 @@ for i in 34:  # TypeError: 'int' object is not iterable
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.29">0.0.1-alpha.29</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20override-of-final-method" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1618" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1641" target="_blank">View source</a>
 </small>
 
 
@@ -1783,7 +1805,7 @@ class B(A):
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20parameter-already-assigned" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1504" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1527" target="_blank">View source</a>
 </small>
 
 
@@ -1810,7 +1832,7 @@ f(1, x=2)  # Error raised here
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.22">0.0.1-alpha.22</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20positional-only-parameter-as-kwarg" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1802" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1852" target="_blank">View source</a>
 </small>
 
 
@@ -1868,7 +1890,7 @@ def test(): -> "int":
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20static-assert-error" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1924" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1974" target="_blank">View source</a>
 </small>
 
 
@@ -1898,7 +1920,7 @@ static_assert(int(2.0 * 3.0) == 6)  # error: does not have a statically known tr
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20subclass-of-final-class" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1595" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1618" target="_blank">View source</a>
 </small>
 
 
@@ -1921,13 +1943,47 @@ class A: ...
 class B(A): ...  # Error raised here
 ```
 
+## `super-call-in-named-tuple-method`
+
+<small>
+Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
+Preview (since <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.30">0.0.1-alpha.30</a>) ·
+<a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20super-call-in-named-tuple-method" target="_blank">Related issues</a> ·
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1786" target="_blank">View source</a>
+</small>
+
+
+**What it does**
+
+Checks for calls to `super()` inside methods of `NamedTuple` classes.
+
+**Why is this bad?**
+
+Using `super()` in a method of a `NamedTuple` class will raise an exception at runtime.
+
+**Examples**
+
+```python
+from typing import NamedTuple
+
+class F(NamedTuple):
+    x: int
+
+    def method(self):
+        super()  # error: super() is not supported in methods of NamedTuple classes
+```
+
+**References**
+
+- [Python documentation: super()](https://docs.python.org/3/library/functions.html#super)
+
 ## `too-many-positional-arguments`
 
 <small>
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20too-many-positional-arguments" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1703" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1726" target="_blank">View source</a>
 </small>
 
 
@@ -1954,7 +2010,7 @@ f("foo")  # Error raised here
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20type-assertion-failure" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1681" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1704" target="_blank">View source</a>
 </small>
 
 
@@ -1982,7 +2038,7 @@ def _(x: int):
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20unavailable-implicit-super-arguments" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1724" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1747" target="_blank">View source</a>
 </small>
 
 
@@ -2028,7 +2084,7 @@ class A:
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20unknown-argument" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1781" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1831" target="_blank">View source</a>
 </small>
 
 
@@ -2055,7 +2111,7 @@ f(x=1, y=2)  # Error raised here
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20unresolved-attribute" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1823" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1873" target="_blank">View source</a>
 </small>
 
 
@@ -2083,7 +2139,7 @@ A().foo  # AttributeError: 'A' object has no attribute 'foo'
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20unresolved-import" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1845" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1895" target="_blank">View source</a>
 </small>
 
 
@@ -2108,7 +2164,7 @@ import foo  # ModuleNotFoundError: No module named 'foo'
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20unresolved-reference" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1864" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1914" target="_blank">View source</a>
 </small>
 
 
@@ -2133,7 +2189,7 @@ print(x)  # NameError: name 'x' is not defined
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20unsupported-bool-conversion" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1473" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1496" target="_blank">View source</a>
 </small>
 
 
@@ -2170,7 +2226,7 @@ b1 < b2 < b1  # exception raised here
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20unsupported-operator" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1883" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1933" target="_blank">View source</a>
 </small>
 
 
@@ -2198,7 +2254,7 @@ A() + A()  # TypeError: unsupported operand type(s) for +: 'A' and 'A'
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20zero-stepsize-in-slice" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1905" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1955" target="_blank">View source</a>
 </small>
 
 
@@ -2223,7 +2279,7 @@ l[1:10:0]  # ValueError: slice step cannot be zero
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'warn'."><code>warn</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.20">0.0.1-alpha.20</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20ambiguous-protocol-member" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L506" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L507" target="_blank">View source</a>
 </small>
 
 
@@ -2264,7 +2320,7 @@ class SubProto(BaseProto, Protocol):
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'warn'."><code>warn</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.16">0.0.1-alpha.16</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20deprecated" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L321" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L322" target="_blank">View source</a>
 </small>
 
 
@@ -2352,7 +2408,7 @@ a = 20 / 0  # type: ignore
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'warn'."><code>warn</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.22">0.0.1-alpha.22</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20possibly-missing-attribute" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1525" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1548" target="_blank">View source</a>
 </small>
 
 
@@ -2380,7 +2436,7 @@ A.c  # AttributeError: type object 'A' has no attribute 'c'
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'warn'."><code>warn</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.22">0.0.1-alpha.22</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20possibly-missing-implicit-call" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L152" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L153" target="_blank">View source</a>
 </small>
 
 
@@ -2412,7 +2468,7 @@ A()[0]  # TypeError: 'A' object is not subscriptable
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'warn'."><code>warn</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.22">0.0.1-alpha.22</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20possibly-missing-import" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1547" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1570" target="_blank">View source</a>
 </small>
 
 
@@ -2444,7 +2500,7 @@ from module import a  # ImportError: cannot import name 'a' from 'module'
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'warn'."><code>warn</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20redundant-cast" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1976" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L2026" target="_blank">View source</a>
 </small>
 
 
@@ -2471,7 +2527,7 @@ cast(int, f())  # Redundant
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'warn'."><code>warn</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20undefined-reveal" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1763" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1813" target="_blank">View source</a>
 </small>
 
 
@@ -2495,7 +2551,7 @@ reveal_type(1)  # NameError: name 'reveal_type' is not defined
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'warn'."><code>warn</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.15">0.0.1-alpha.15</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20unresolved-global" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1997" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L2047" target="_blank">View source</a>
 </small>
 
 
@@ -2553,7 +2609,7 @@ def g():
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'warn'."><code>warn</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.7">0.0.1-alpha.7</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20unsupported-base" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L755" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L778" target="_blank">View source</a>
 </small>
 
 
@@ -2592,7 +2648,7 @@ class D(C): ...  # error: [unsupported-base]
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'warn'."><code>warn</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.22">0.0.1-alpha.22</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20useless-overload-body" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1061" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1084" target="_blank">View source</a>
 </small>
 
 
@@ -2655,7 +2711,7 @@ def foo(x: int | str) -> int | str:
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'ignore'."><code>ignore</code></a> ·
 Preview (since <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a>) ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20division-by-zero" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L303" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L304" target="_blank">View source</a>
 </small>
 
 
@@ -2679,7 +2735,7 @@ Dividing by zero raises a `ZeroDivisionError` at runtime.
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'ignore'."><code>ignore</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20possibly-unresolved-reference" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1573" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1596" target="_blank">View source</a>
 </small>
 
 

crates/ty_completion_eval/completion-evaluation-tasks.csv

@@ -25,4 +25,4 @@ scope-simple-long-identifier,main.py,0,1
 tstring-completions,main.py,0,1
 ty-extensions-lower-stdlib,main.py,0,8
 type-var-typing-over-ast,main.py,0,3
-type-var-typing-over-ast,main.py,1,278
+type-var-typing-over-ast,main.py,1,275

crates/ty_ide/src/all_symbols.rs

@@ -1,6 +1,6 @@
 use ruff_db::files::File;
 use ty_project::Db;
-use ty_python_semantic::{Module, all_modules};
+use ty_python_semantic::{Module, ModuleName, all_modules, resolve_real_shadowable_module};
 
 use crate::symbols::{QueryPattern, SymbolInfo, symbols_for_file_global_only};
 
@@ -8,12 +8,20 @@ use crate::symbols::{QueryPattern, SymbolInfo, symbols_for_file_global_only};
 ///
 /// Returns symbols from all files in the workspace and dependencies, filtered
 /// by the query.
-pub fn all_symbols<'db>(db: &'db dyn Db, query: &QueryPattern) -> Vec<AllSymbolInfo<'db>> {
+pub fn all_symbols<'db>(
+    db: &'db dyn Db,
+    importing_from: File,
+    query: &QueryPattern,
+) -> Vec<AllSymbolInfo<'db>> {
     // If the query is empty, return immediately to avoid expensive file scanning
     if query.will_match_everything() {
         return Vec::new();
     }
 
+    let typing_extensions = ModuleName::new("typing_extensions").unwrap();
+    let is_typing_extensions_available = importing_from.is_stub(db)
+        || resolve_real_shadowable_module(db, &typing_extensions).is_some();
+
     let results = std::sync::Mutex::new(Vec::new());
     {
         let modules = all_modules(db);
@@ -28,6 +36,11 @@ pub fn all_symbols<'db>(db: &'db dyn Db, query: &QueryPattern) -> Vec<AllSymbolI
                 let Some(file) = module.file(&*db) else {
                     continue;
                 };
+                // TODO: also make it available in `TYPE_CHECKING` blocks
+                // (we'd need https://github.com/astral-sh/ty/issues/1553 to do this well)
+                if !is_typing_extensions_available && module.name(&*db) == &typing_extensions {
+                    continue;
+                }
                 s.spawn(move |_| {
                     for (_, symbol) in symbols_for_file_global_only(&*db, file).search(query) {
                         // It seems like we could do better here than
@@ -143,7 +156,7 @@ ABCDEFGHIJKLMNOP = 'https://api.example.com'
 
     impl CursorTest {
         fn all_symbols(&self, query: &str) -> String {
-            let symbols = all_symbols(&self.db, &QueryPattern::fuzzy(query));
+            let symbols = all_symbols(&self.db, self.cursor.file, &QueryPattern::fuzzy(query));
 
             if symbols.is_empty() {
                 return "No symbols found".to_string();

crates/ty_ide/src/code_action.rs

@@ -1,8 +1,10 @@
 use crate::{completion, find_node::covering_node};
+
 use ruff_db::{files::File, parsed::parsed_module};
 use ruff_diagnostics::Edit;
 use ruff_text_size::TextRange;
 use ty_project::Db;
+use ty_python_semantic::create_suppression_fix;
 use ty_python_semantic::types::UNRESOLVED_REFERENCE;
 
 /// A `QuickFix` Code Action
@@ -18,26 +20,501 @@ pub fn code_actions(
     file: File,
     diagnostic_range: TextRange,
     diagnostic_id: &str,
-) -> Option<Vec<QuickFix>> {
+) -> Vec<QuickFix> {
     let registry = db.lint_registry();
     let Ok(lint_id) = registry.get(diagnostic_id) else {
-        return None;
+        return Vec::new();
     };
-    if lint_id.name() == UNRESOLVED_REFERENCE.name() {
-        let parsed = parsed_module(db, file).load(db);
-        let node = covering_node(parsed.syntax().into(), diagnostic_range).node();
-        let symbol = &node.expr_name()?.id;
 
-        let fixes = completion::missing_imports(db, file, &parsed, symbol, node)
+    let mut actions = Vec::new();
+
+    if lint_id.name() == UNRESOLVED_REFERENCE.name()
+        && let Some(import_quick_fix) = create_import_symbol_quick_fix(db, file, diagnostic_range)
+    {
+        actions.extend(import_quick_fix);
+    }
+
+    actions.push(QuickFix {
+        title: format!("Ignore '{}' for this line", lint_id.name()),
+        edits: create_suppression_fix(db, file, lint_id, diagnostic_range).into_edits(),
+        preferred: false,
+    });
+
+    actions
+}
+
+fn create_import_symbol_quick_fix(
+    db: &dyn Db,
+    file: File,
+    diagnostic_range: TextRange,
+) -> Option<impl Iterator<Item = QuickFix>> {
+    let parsed = parsed_module(db, file).load(db);
+    let node = covering_node(parsed.syntax().into(), diagnostic_range).node();
+    let symbol = &node.expr_name()?.id;
+
+    Some(
+        completion::missing_imports(db, file, &parsed, symbol, node)
             .into_iter()
             .map(|import| QuickFix {
                 title: import.label,
                 edits: vec![import.edit],
                 preferred: true,
-            })
-            .collect();
-        Some(fixes)
-    } else {
-        None
+            }),
+    )
+}
+
+#[cfg(test)]
+mod tests {
+
+    use crate::code_actions;
+
+    use insta::assert_snapshot;
+    use ruff_db::{
+        diagnostic::{
+            Annotation, Diagnostic, DiagnosticFormat, DiagnosticId, DisplayDiagnosticConfig,
+            LintName, Span, SubDiagnostic,
+        },
+        files::{File, system_path_to_file},
+        system::{DbWithWritableSystem, SystemPathBuf},
+    };
+    use ruff_diagnostics::Fix;
+    use ruff_text_size::{TextRange, TextSize};
+    use ty_project::ProjectMetadata;
+    use ty_python_semantic::{lint::LintMetadata, types::UNRESOLVED_REFERENCE};
+
+    #[test]
+    fn add_ignore() {
+        let test = CodeActionTest::with_source(r#"b = <START>a<END> / 10"#);
+
+        assert_snapshot!(test.code_actions(&UNRESOLVED_REFERENCE), @r"
+        info[code-action]: Ignore 'unresolved-reference' for this line
+         --> main.py:1:5
+          |
+        1 | b = a / 10
+          |     ^
+          |
+          - b = a / 10
+        1 + b = a / 10  # ty:ignore[unresolved-reference]
+        ");
+    }
+
+    #[test]
+    fn add_ignore_existing_comment() {
+        let test = CodeActionTest::with_source(r#"b = <START>a<END> / 10  # fmt: off"#);
+
+        assert_snapshot!(test.code_actions(&UNRESOLVED_REFERENCE), @r"
+        info[code-action]: Ignore 'unresolved-reference' for this line
+         --> main.py:1:5
+          |
+        1 | b = a / 10  # fmt: off
+          |     ^
+          |
+          - b = a / 10  # fmt: off
+        1 + b = a / 10  # fmt: off  # ty:ignore[unresolved-reference]
+        ");
+    }
+
+    #[test]
+    fn add_ignore_trailing_whitespace() {
+        let test = CodeActionTest::with_source(r#"b = <START>a<END> / 10  "#);
+
+        assert_snapshot!(test.code_actions(&UNRESOLVED_REFERENCE), @r"
+        info[code-action]: Ignore 'unresolved-reference' for this line
+         --> main.py:1:5
+          |
+        1 | b = a / 10  
+          |     ^
+          |
+          - b = a / 10  
+        1 + b = a / 10  # ty:ignore[unresolved-reference]
+        ");
+    }
+
+    #[test]
+    fn add_code_existing_ignore() {
+        let test = CodeActionTest::with_source(
+            r#"
+            b = <START>a<END> / 0  # ty:ignore[division-by-zero]
+        "#,
+        );
+
+        assert_snapshot!(test.code_actions(&UNRESOLVED_REFERENCE), @r"
+        info[code-action]: Ignore 'unresolved-reference' for this line
+         --> main.py:2:17
+          |
+        2 |             b = a / 0  # ty:ignore[division-by-zero]
+          |                 ^
+          |
+        1 | 
+          -             b = a / 0  # ty:ignore[division-by-zero]
+        2 +             b = a / 0  # ty:ignore[division-by-zero, unresolved-reference]
+        3 |
+        ");
+    }
+
+    #[test]
+    fn add_code_existing_ignore_trailing_comma() {
+        let test = CodeActionTest::with_source(
+            r#"
+            b = <START>a<END> / 0  # ty:ignore[division-by-zero,]
+        "#,
+        );
+
+        assert_snapshot!(test.code_actions(&UNRESOLVED_REFERENCE), @r"
+        info[code-action]: Ignore 'unresolved-reference' for this line
+         --> main.py:2:17
+          |
+        2 |             b = a / 0  # ty:ignore[division-by-zero,]
+          |                 ^
+          |
+        1 | 
+          -             b = a / 0  # ty:ignore[division-by-zero,]
+        2 +             b = a / 0  # ty:ignore[division-by-zero, unresolved-reference]
+        3 |
+        ");
+    }
+
+    #[test]
+    fn add_code_existing_ignore_trailing_whitespace() {
+        let test = CodeActionTest::with_source(
+            r#"
+            b = <START>a<END> / 0  # ty:ignore[division-by-zero   ]
+        "#,
+        );
+
+        assert_snapshot!(test.code_actions(&UNRESOLVED_REFERENCE), @r"
+        info[code-action]: Ignore 'unresolved-reference' for this line
+         --> main.py:2:17
+          |
+        2 |             b = a / 0  # ty:ignore[division-by-zero   ]
+          |                 ^
+          |
+        1 | 
+          -             b = a / 0  # ty:ignore[division-by-zero   ]
+        2 +             b = a / 0  # ty:ignore[division-by-zero, unresolved-reference   ]
+        3 |
+        ");
+    }
+
+    #[test]
+    fn add_code_existing_ignore_with_reason() {
+        let test = CodeActionTest::with_source(
+            r#"
+            b = <START>a<END> / 0  # ty:ignore[division-by-zero] some explanation
+        "#,
+        );
+
+        assert_snapshot!(test.code_actions(&UNRESOLVED_REFERENCE), @r"
+        info[code-action]: Ignore 'unresolved-reference' for this line
+         --> main.py:2:17
+          |
+        2 |             b = a / 0  # ty:ignore[division-by-zero] some explanation
+          |                 ^
+          |
+        1 | 
+          -             b = a / 0  # ty:ignore[division-by-zero] some explanation
+        2 +             b = a / 0  # ty:ignore[division-by-zero] some explanation  # ty:ignore[unresolved-reference]
+        3 |
+        ");
+    }
+
+    #[test]
+    fn add_code_existing_ignore_start_line() {
+        let test = CodeActionTest::with_source(
+            r#"
+            b = (
+                    <START>a  # ty:ignore[division-by-zero]
+                    /
+                    0<END>
+            )
+        "#,
+        );
+
+        assert_snapshot!(test.code_actions(&UNRESOLVED_REFERENCE), @r"
+        info[code-action]: Ignore 'unresolved-reference' for this line
+         --> main.py:3:21
+          |
+        2 |               b = (
+        3 | /                     a  # ty:ignore[division-by-zero]
+        4 | |                     /
+        5 | |                     0
+          | |_____________________^
+        6 |               )
+          |
+        1 | 
+        2 |             b = (
+          -                     a  # ty:ignore[division-by-zero]
+        3 +                     a  # ty:ignore[division-by-zero, unresolved-reference]
+        4 |                     /
+        5 |                     0
+        6 |             )
+        ");
+    }
+
+    #[test]
+    fn add_code_existing_ignore_end_line() {
+        let test = CodeActionTest::with_source(
+            r#"
+            b = (
+                    <START>a
+                    /
+                    0<END>  # ty:ignore[division-by-zero]
+            )
+        "#,
+        );
+
+        assert_snapshot!(test.code_actions(&UNRESOLVED_REFERENCE), @r"
+        info[code-action]: Ignore 'unresolved-reference' for this line
+         --> main.py:3:21
+          |
+        2 |               b = (
+        3 | /                     a
+        4 | |                     /
+        5 | |                     0  # ty:ignore[division-by-zero]
+          | |_____________________^
+        6 |               )
+          |
+        2 |             b = (
+        3 |                     a
+        4 |                     /
+          -                     0  # ty:ignore[division-by-zero]
+        5 +                     0  # ty:ignore[division-by-zero, unresolved-reference]
+        6 |             )
+        7 |
+        ");
+    }
+
+    #[test]
+    fn add_code_existing_ignores() {
+        let test = CodeActionTest::with_source(
+            r#"
+            b = (
+                    <START>a  # ty:ignore[division-by-zero]
+                    /
+                    0<END>  # ty:ignore[division-by-zero]
+            )
+        "#,
+        );
+
+        assert_snapshot!(test.code_actions(&UNRESOLVED_REFERENCE), @r"
+        info[code-action]: Ignore 'unresolved-reference' for this line
+         --> main.py:3:21
+          |
+        2 |               b = (
+        3 | /                     a  # ty:ignore[division-by-zero]
+        4 | |                     /
+        5 | |                     0  # ty:ignore[division-by-zero]
+          | |_____________________^
+        6 |               )
+          |
+        1 | 
+        2 |             b = (
+          -                     a  # ty:ignore[division-by-zero]
+        3 +                     a  # ty:ignore[division-by-zero, unresolved-reference]
+        4 |                     /
+        5 |                     0  # ty:ignore[division-by-zero]
+        6 |             )
+        ");
+    }
+
+    #[test]
+    fn add_code_interpolated_string() {
+        let test = CodeActionTest::with_source(
+            r#"
+            b = f"""
+                {<START>a<END>}
+                more text
+            """
+        "#,
+        );
+
+        assert_snapshot!(test.code_actions(&UNRESOLVED_REFERENCE), @r#"
+        info[code-action]: Ignore 'unresolved-reference' for this line
+         --> main.py:3:18
+          |
+        2 |             b = f"""
+        3 |                 {a}
+          |                  ^
+        4 |                 more text
+        5 |             """
+          |
+        2 |             b = f"""
+        3 |                 {a}
+        4 |                 more text
+          -             """
+        5 +             """  # ty:ignore[unresolved-reference]
+        6 |
+        "#);
+    }
+
+    #[test]
+    fn add_code_multiline_interpolation() {
+        let test = CodeActionTest::with_source(
+            r#"
+            b = f"""
+                {
+                <START>a<END>
+                }
+                more text
+            """
+        "#,
+        );
+
+        assert_snapshot!(test.code_actions(&UNRESOLVED_REFERENCE), @r#"
+        info[code-action]: Ignore 'unresolved-reference' for this line
+         --> main.py:4:17
+          |
+        2 |             b = f"""
+        3 |                 {
+        4 |                 a
+          |                 ^
+        5 |                 }
+        6 |                 more text
+          |
+        1 | 
+        2 |             b = f"""
+        3 |                 {
+          -                 a
+        4 +                 a  # ty:ignore[unresolved-reference]
+        5 |                 }
+        6 |                 more text
+        7 |             """
+        "#);
+    }
+
+    #[test]
+    fn add_code_followed_by_multiline_string() {
+        let test = CodeActionTest::with_source(
+            r#"
+            b = <START>a<END> + """
+                more text
+            """
+        "#,
+        );
+
+        assert_snapshot!(test.code_actions(&UNRESOLVED_REFERENCE), @r#"
+        info[code-action]: Ignore 'unresolved-reference' for this line
+         --> main.py:2:17
+          |
+        2 |             b = a + """
+          |                 ^
+        3 |                 more text
+        4 |             """
+          |
+        1 | 
+        2 |             b = a + """
+        3 |                 more text
+          -             """
+        4 +             """  # ty:ignore[unresolved-reference]
+        5 |
+        "#);
+    }
+
+    #[test]
+    fn add_code_followed_by_continuation() {
+        let test = CodeActionTest::with_source(
+            r#"
+            b = <START>a<END> \
+            + "test"
+        "#,
+        );
+
+        assert_snapshot!(test.code_actions(&UNRESOLVED_REFERENCE), @r#"
+        info[code-action]: Ignore 'unresolved-reference' for this line
+         --> main.py:2:17
+          |
+        2 |             b = a \
+          |                 ^
+        3 |             + "test"
+          |
+        1 | 
+        2 |             b = a \
+          -             + "test"
+        3 +             + "test"  # ty:ignore[unresolved-reference]
+        4 |
+        "#);
+    }
+
+    pub(super) struct CodeActionTest {
+        pub(super) db: ty_project::TestDb,
+        pub(super) file: File,
+        pub(super) diagnostic_range: TextRange,
+    }
+
+    impl CodeActionTest {
+        pub(super) fn with_source(source: &str) -> Self {
+            let mut db = ty_project::TestDb::new(ProjectMetadata::new(
+                "test".into(),
+                SystemPathBuf::from("/"),
+            ));
+
+            db.init_program().unwrap();
+
+            let mut cleansed = source.to_string();
+
+            let start = cleansed
+                .find("<START>")
+                .expect("source text should contain a `<START>` marker");
+            cleansed.replace_range(start..start + "<START>".len(), "");
+
+            let end = cleansed
+                .find("<END>")
+                .expect("source text should contain a `<END>` marker");
+
+            cleansed.replace_range(end..end + "<END>".len(), "");
+
+            assert!(start <= end, "<START> marker should be before <END> marker");
+
+            db.write_file("main.py", cleansed)
+                .expect("write to memory file system to be successful");
+
+            let file = system_path_to_file(&db, "main.py").expect("newly written file to existing");
+
+            Self {
+                db,
+                file,
+                diagnostic_range: TextRange::new(
+                    TextSize::try_from(start).unwrap(),
+                    TextSize::try_from(end).unwrap(),
+                ),
+            }
+        }
+
+        pub(super) fn code_actions(&self, lint: &'static LintMetadata) -> String {
+            use std::fmt::Write;
+
+            let mut buf = String::new();
+
+            let config = DisplayDiagnosticConfig::default()
+                .color(false)
+                .show_fix_diff(true)
+                .format(DiagnosticFormat::Full);
+
+            for mut action in code_actions(&self.db, self.file, self.diagnostic_range, &lint.name) {
+                let mut diagnostic = Diagnostic::new(
+                    DiagnosticId::Lint(LintName::of("code-action")),
+                    ruff_db::diagnostic::Severity::Info,
+                    action.title,
+                );
+
+                diagnostic.annotate(Annotation::primary(
+                    Span::from(self.file).with_range(self.diagnostic_range),
+                ));
+
+                if action.preferred {
+                    diagnostic.sub(SubDiagnostic::new(
+                        ruff_db::diagnostic::SubDiagnosticSeverity::Help,
+                        "This is a preferred code action",
+                    ));
+                }
+
+                let first_edit = action.edits.remove(0);
+                diagnostic.set_fix(Fix::safe_edits(first_edit, action.edits));
+
+                write!(buf, "{}", diagnostic.display(&self.db, &config)).unwrap();
+            }
+
+            buf
+        }
     }
 }

crates/ty_ide/src/completion.rs

@@ -417,7 +417,16 @@ pub fn completion<'db>(
         }
         if settings.auto_import {
             if let Some(scoped) = scoped {
-                add_unimported_completions(db, file, &parsed, scoped, &mut completions);
+                add_unimported_completions(
+                    db,
+                    file,
+                    &parsed,
+                    scoped,
+                    |module_name: &ModuleName, symbol: &str| {
+                        ImportRequest::import_from(module_name.as_str(), symbol)
+                    },
+                    &mut completions,
+                );
             }
         }
     }
@@ -453,7 +462,16 @@ pub(crate) fn missing_imports(
 ) -> Vec<ImportEdit> {
     let mut completions = Completions::exactly(db, symbol);
     let scoped = ScopedTarget { node };
-    add_unimported_completions(db, file, parsed, scoped, &mut completions);
+    add_unimported_completions(
+        db,
+        file,
+        parsed,
+        scoped,
+        |module_name: &ModuleName, symbol: &str| {
+            ImportRequest::import_from(module_name.as_str(), symbol).force()
+        },
+        &mut completions,
+    );
 
     completions.into_imports()
 }
@@ -502,6 +520,7 @@ fn add_unimported_completions<'db>(
     file: File,
     parsed: &ParsedModuleRef,
     scoped: ScopedTarget<'_>,
+    create_import_request: impl for<'a> Fn(&'a ModuleName, &'a str) -> ImportRequest<'a>,
     completions: &mut Completions<'db>,
 ) {
     // This is redundant since `all_symbols` will also bail
@@ -517,14 +536,13 @@ fn add_unimported_completions<'db>(
     let importer = Importer::new(db, &stylist, file, source.as_str(), parsed);
     let members = importer.members_in_scope_at(scoped.node, scoped.node.start());
 
-    for symbol in all_symbols(db, &completions.query) {
+    for symbol in all_symbols(db, file, &completions.query) {
         if symbol.module.file(db) == Some(file) || symbol.module.is_known(db, KnownModule::Builtins)
         {
             continue;
         }
 
-        let request =
-            ImportRequest::import_from(symbol.module.name(db).as_str(), &symbol.symbol.name);
+        let request = create_import_request(symbol.module.name(db), &symbol.symbol.name);
         // FIXME: `all_symbols` doesn't account for wildcard imports.
         // Since we're looking at every module, this is probably
         // "fine," but it might mean that we import a symbol from the
@@ -5566,10 +5584,7 @@ def foo(param: s<CURSOR>)
     #[test]
     fn from_import_no_space_not_suggests_import() {
         let builder = completion_test_builder("from typing<CURSOR>");
-        assert_snapshot!(builder.build().snapshot(), @r"
-        typing
-        typing_extensions
-        ");
+        assert_snapshot!(builder.build().snapshot(), @"typing");
     }
 
     #[test]
@@ -5785,6 +5800,86 @@ from .imp<CURSOR>
         ");
     }
 
+    #[test]
+    fn typing_extensions_excluded_from_import() {
+        let builder = completion_test_builder("from typing<CURSOR>").module_names();
+        assert_snapshot!(builder.build().snapshot(), @"typing :: Current module");
+    }
+
+    #[test]
+    fn typing_extensions_excluded_from_auto_import() {
+        let builder = completion_test_builder("deprecated<CURSOR>")
+            .auto_import()
+            .module_names();
+        assert_snapshot!(builder.build().snapshot(), @r"
+        Deprecated :: importlib.metadata
+        DeprecatedList :: importlib.metadata
+        DeprecatedNonAbstract :: importlib.metadata
+        DeprecatedTuple :: importlib.metadata
+        deprecated :: warnings
+        ");
+    }
+
+    #[test]
+    fn typing_extensions_included_from_import() {
+        let builder = CursorTest::builder()
+            .source("typing_extensions.py", "deprecated = 1")
+            .source("foo.py", "from typing<CURSOR>")
+            .completion_test_builder()
+            .module_names();
+        assert_snapshot!(builder.build().snapshot(), @r"
+        typing :: Current module
+        typing_extensions :: Current module
+        ");
+    }
+
+    #[test]
+    fn typing_extensions_included_from_auto_import() {
+        let builder = CursorTest::builder()
+            .source("typing_extensions.py", "deprecated = 1")
+            .source("foo.py", "deprecated<CURSOR>")
+            .completion_test_builder()
+            .auto_import()
+            .module_names();
+        assert_snapshot!(builder.build().snapshot(), @r"
+        Deprecated :: importlib.metadata
+        DeprecatedList :: importlib.metadata
+        DeprecatedNonAbstract :: importlib.metadata
+        DeprecatedTuple :: importlib.metadata
+        deprecated :: typing_extensions
+        deprecated :: warnings
+        ");
+    }
+
+    #[test]
+    fn typing_extensions_included_from_import_in_stub() {
+        let builder = CursorTest::builder()
+            .source("foo.pyi", "from typing<CURSOR>")
+            .completion_test_builder()
+            .module_names();
+        assert_snapshot!(builder.build().snapshot(), @r"
+        typing :: Current module
+        typing_extensions :: Current module
+        ");
+    }
+
+    #[test]
+    fn typing_extensions_included_from_auto_import_in_stub() {
+        let builder = CursorTest::builder()
+            .source("foo.pyi", "deprecated<CURSOR>")
+            .completion_test_builder()
+            .auto_import()
+            .module_names();
+        assert_snapshot!(builder.build().snapshot(), @r"
+        Deprecated :: importlib.metadata
+        DeprecatedList :: importlib.metadata
+        DeprecatedNonAbstract :: importlib.metadata
+        DeprecatedTuple :: importlib.metadata
+        deprecated :: typing_extensions
+        deprecated :: warnings
+        ");
+    }
+
     /// A way to create a simple single-file (named `main.py`) completion test
     /// builder.
     ///

crates/ty_ide/src/find_references.rs

@@ -1656,4 +1656,218 @@ func<CURSOR>_alias()
           |
         ");
     }
+
+    #[test]
+    fn stub_target() {
+        let test = CursorTest::builder()
+            .source(
+                "path.pyi",
+                r#"
+                class Path:
+                    def __init__(self, path: str): ...
+            "#,
+            )
+            .source(
+                "path.py",
+                r#"
+                class Path:
+                    def __init__(self, path: str):
+                        self.path = path
+            "#,
+            )
+            .source(
+                "importer.py",
+                r#"
+                from path import Path<CURSOR>
+
+                a: Path = Path("test")
+                "#,
+            )
+            .build();
+
+        assert_snapshot!(test.references(), @r###"
+        info[references]: Reference 1
+         --> path.pyi:2:7
+          |
+        2 | class Path:
+          |       ^^^^
+        3 |     def __init__(self, path: str): ...
+          |
+
+        info[references]: Reference 2
+         --> importer.py:2:18
+          |
+        2 | from path import Path
+          |                  ^^^^
+        3 |
+        4 | a: Path = Path("test")
+          |
+
+        info[references]: Reference 3
+         --> importer.py:4:4
+          |
+        2 | from path import Path
+        3 |
+        4 | a: Path = Path("test")
+          |    ^^^^
+          |
+
+        info[references]: Reference 4
+         --> importer.py:4:11
+          |
+        2 | from path import Path
+        3 |
+        4 | a: Path = Path("test")
+          |           ^^^^
+          |
+        "###);
+    }
+
+    #[test]
+    fn import_alias() {
+        let test = CursorTest::builder()
+            .source(
+                "main.py",
+                r#"
+                import warnings
+                import warnings as <CURSOR>abc
+
+                x = abc
+                y = warnings
+            "#,
+            )
+            .build();
+
+        assert_snapshot!(test.references(), @r"
+        info[references]: Reference 1
+         --> main.py:3:20
+          |
+        2 | import warnings
+        3 | import warnings as abc
+          |                    ^^^
+        4 |
+        5 | x = abc
+          |
+
+        info[references]: Reference 2
+         --> main.py:5:5
+          |
+        3 | import warnings as abc
+        4 |
+        5 | x = abc
+          |     ^^^
+        6 | y = warnings
+          |
+        ");
+    }
+
+    #[test]
+    fn import_alias_use() {
+        let test = CursorTest::builder()
+            .source(
+                "main.py",
+                r#"
+                import warnings
+                import warnings as abc
+
+                x = abc<CURSOR>
+                y = warnings
+            "#,
+            )
+            .build();
+
+        assert_snapshot!(test.references(), @r"
+        info[references]: Reference 1
+         --> main.py:3:20
+          |
+        2 | import warnings
+        3 | import warnings as abc
+          |                    ^^^
+        4 |
+        5 | x = abc
+          |
+
+        info[references]: Reference 2
+         --> main.py:5:5
+          |
+        3 | import warnings as abc
+        4 |
+        5 | x = abc
+          |     ^^^
+        6 | y = warnings
+          |
+        ");
+    }
+
+    #[test]
+    fn import_from_alias() {
+        let test = CursorTest::builder()
+            .source(
+                "main.py",
+                r#"
+                from warnings import deprecated as xyz<CURSOR>
+                from warnings import deprecated
+
+                y = xyz
+                z = deprecated
+            "#,
+            )
+            .build();
+
+        assert_snapshot!(test.references(), @r"
+        info[references]: Reference 1
+         --> main.py:2:36
+          |
+        2 | from warnings import deprecated as xyz
+          |                                    ^^^
+        3 | from warnings import deprecated
+          |
+
+        info[references]: Reference 2
+         --> main.py:5:5
+          |
+        3 | from warnings import deprecated
+        4 |
+        5 | y = xyz
+          |     ^^^
+        6 | z = deprecated
+          |
+        ");
+    }
+
+    #[test]
+    fn import_from_alias_use() {
+        let test = CursorTest::builder()
+            .source(
+                "main.py",
+                r#"
+                from warnings import deprecated as xyz
+                from warnings import deprecated
+
+                y = xyz<CURSOR>
+                z = deprecated
+            "#,
+            )
+            .build();
+
+        assert_snapshot!(test.references(), @r"
+        info[references]: Reference 1
+         --> main.py:2:36
+          |
+        2 | from warnings import deprecated as xyz
+          |                                    ^^^
+        3 | from warnings import deprecated
+          |
+
+        info[references]: Reference 2
+         --> main.py:5:5
+          |
+        3 | from warnings import deprecated
+        4 |
+        5 | y = xyz
+          |     ^^^
+        6 | z = deprecated
+          |
+        ");
+    }
 }

crates/ty_ide/src/goto.rs

@@ -334,15 +334,24 @@ impl GotoTarget<'_> {
                 let (_, ty) = ty_python_semantic::definitions_for_unary_op(model, expression)?;
                 ty
             }
-            // TODO: Support identifier targets
-            GotoTarget::PatternMatchRest(_)
-            | GotoTarget::PatternKeywordArgument(_)
-            | GotoTarget::PatternMatchStarName(_)
-            | GotoTarget::PatternMatchAsName(_)
-            | GotoTarget::TypeParamParamSpecName(_)
-            | GotoTarget::TypeParamTypeVarTupleName(_)
-            | GotoTarget::NonLocal { .. }
-            | GotoTarget::Globals { .. } => return None,
+            GotoTarget::PatternMatchRest(pattern) => {
+                model.inferred_type_for_identifier(pattern.rest.as_ref()?)
+            }
+            GotoTarget::PatternKeywordArgument(pattern) => {
+                model.inferred_type_for_identifier(&pattern.attr)
+            }
+            GotoTarget::PatternMatchStarName(pattern) => {
+                model.inferred_type_for_identifier(pattern.name.as_ref()?)
+            }
+            GotoTarget::PatternMatchAsName(pattern) => {
+                model.inferred_type_for_identifier(pattern.name.as_ref()?)
+            }
+            GotoTarget::NonLocal { identifier } => model.inferred_type_for_identifier(identifier),
+            GotoTarget::Globals { identifier } => model.inferred_type_for_identifier(identifier),
+            // These don't really... *have* a type?
+            GotoTarget::TypeParamParamSpecName(_) | GotoTarget::TypeParamTypeVarTupleName(_) => {
+                return None;
+            }
         };
 
         Some(ty)
@@ -396,13 +405,19 @@ impl GotoTarget<'_> {
             GotoTarget::ImportSymbolAlias {
                 alias, import_from, ..
             } => {
-                let symbol_name = alias.name.as_str();
-                Some(definitions_for_imported_symbol(
-                    model,
-                    import_from,
-                    symbol_name,
-                    alias_resolution,
-                ))
+                if let Some(asname) = alias.asname.as_ref()
+                    && alias_resolution == ImportAliasResolution::PreserveAliases
+                {
+                    Some(definitions_for_name(model, asname.as_str(), asname.into()))
+                } else {
+                    let symbol_name = alias.name.as_str();
+                    Some(definitions_for_imported_symbol(
+                        model,
+                        import_from,
+                        symbol_name,
+                        alias_resolution,
+                    ))
+                }
             }
 
             GotoTarget::ImportModuleComponent {
@@ -418,12 +433,12 @@ impl GotoTarget<'_> {
 
             // Handle import aliases (offset within 'z' in "import x.y as z")
             GotoTarget::ImportModuleAlias { alias } => {
-                if alias_resolution == ImportAliasResolution::ResolveAliases {
-                    definitions_for_module(model, Some(alias.name.as_str()), 0)
+                if let Some(asname) = alias.asname.as_ref()
+                    && alias_resolution == ImportAliasResolution::PreserveAliases
+                {
+                    Some(definitions_for_name(model, asname.as_str(), asname.into()))
                 } else {
-                    alias.asname.as_ref().map(|name| {
-                        definitions_for_name(model, name.as_str(), AnyNodeRef::Identifier(name))
-                    })
+                    definitions_for_module(model, Some(alias.name.as_str()), 0)
                 }
             }
 

crates/ty_ide/src/goto_type_definition.rs

@@ -975,7 +975,26 @@ mod tests {
             "#,
         );
 
-        assert_snapshot!(test.goto_type_definition(), @"No goto target found");
+        assert_snapshot!(test.goto_type_definition(), @r#"
+        info[goto-type-definition]: Type definition
+          --> stdlib/ty_extensions.pyi:20:1
+           |
+        19 | # Types
+        20 | Unknown = object()
+           | ^^^^^^^
+        21 | AlwaysTruthy = object()
+        22 | AlwaysFalsy = object()
+           |
+        info: Source
+         --> main.py:4:22
+          |
+        2 | def my_func(command: str):
+        3 |     match command.split():
+        4 |         case ["get", ab]:
+          |                      ^^
+        5 |             x = ab
+          |
+        "#);
     }
 
     #[test]
@@ -1003,7 +1022,26 @@ mod tests {
             "#,
         );
 
-        assert_snapshot!(test.goto_type_definition(), @"No goto target found");
+        assert_snapshot!(test.goto_type_definition(), @r#"
+        info[goto-type-definition]: Type definition
+          --> stdlib/ty_extensions.pyi:20:1
+           |
+        19 | # Types
+        20 | Unknown = object()
+           | ^^^^^^^
+        21 | AlwaysTruthy = object()
+        22 | AlwaysFalsy = object()
+           |
+        info: Source
+         --> main.py:4:23
+          |
+        2 | def my_func(command: str):
+        3 |     match command.split():
+        4 |         case ["get", *ab]:
+          |                       ^^
+        5 |             x = ab
+          |
+        "#);
     }
 
     #[test]
@@ -1031,7 +1069,26 @@ mod tests {
             "#,
         );
 
-        assert_snapshot!(test.goto_type_definition(), @"No goto target found");
+        assert_snapshot!(test.goto_type_definition(), @r#"
+        info[goto-type-definition]: Type definition
+          --> stdlib/ty_extensions.pyi:20:1
+           |
+        19 | # Types
+        20 | Unknown = object()
+           | ^^^^^^^
+        21 | AlwaysTruthy = object()
+        22 | AlwaysFalsy = object()
+           |
+        info: Source
+         --> main.py:4:37
+          |
+        2 | def my_func(command: str):
+        3 |     match command.split():
+        4 |         case ["get", ("a" | "b") as ab]:
+          |                                     ^^
+        5 |             x = ab
+          |
+        "#);
     }
 
     #[test]
@@ -1065,7 +1122,26 @@ mod tests {
             "#,
         );
 
-        assert_snapshot!(test.goto_type_definition(), @"No goto target found");
+        assert_snapshot!(test.goto_type_definition(), @r"
+        info[goto-type-definition]: Type definition
+          --> stdlib/ty_extensions.pyi:20:1
+           |
+        19 | # Types
+        20 | Unknown = object()
+           | ^^^^^^^
+        21 | AlwaysTruthy = object()
+        22 | AlwaysFalsy = object()
+           |
+        info: Source
+          --> main.py:10:30
+           |
+         8 | def my_func(event: Click):
+         9 |     match event:
+        10 |         case Click(x, button=ab):
+           |                              ^^
+        11 |             x = ab
+           |
+        ");
     }
 
     #[test]
@@ -1143,7 +1219,26 @@ mod tests {
             "#,
         );
 
-        assert_snapshot!(test.goto_type_definition(), @"No goto target found");
+        assert_snapshot!(test.goto_type_definition(), @r"
+        info[goto-type-definition]: Type definition
+          --> stdlib/ty_extensions.pyi:20:1
+           |
+        19 | # Types
+        20 | Unknown = object()
+           | ^^^^^^^
+        21 | AlwaysTruthy = object()
+        22 | AlwaysFalsy = object()
+           |
+        info: Source
+          --> main.py:10:23
+           |
+         8 | def my_func(event: Click):
+         9 |     match event:
+        10 |         case Click(x, button=ab):
+           |                       ^^^^^^
+        11 |             x = ab
+           |
+        ");
     }
 
     #[test]
@@ -1395,7 +1490,26 @@ def outer():
         );
 
         // Should find the variable declaration in the outer scope, not the nonlocal statement
-        assert_snapshot!(test.goto_type_definition(), @"No goto target found");
+        assert_snapshot!(test.goto_type_definition(), @r#"
+        info[goto-type-definition]: Type definition
+          --> stdlib/ty_extensions.pyi:20:1
+           |
+        19 | # Types
+        20 | Unknown = object()
+           | ^^^^^^^
+        21 | AlwaysTruthy = object()
+        22 | AlwaysFalsy = object()
+           |
+        info: Source
+         --> main.py:6:18
+          |
+        5 |     def inner():
+        6 |         nonlocal xy
+          |                  ^^
+        7 |         xy = "modified"
+        8 |         return x  # Should find the nonlocal x declaration in outer scope
+          |
+        "#);
     }
 
     #[test]
@@ -1447,7 +1561,26 @@ def function():
         );
 
         // Should find the global variable declaration, not the global statement
-        assert_snapshot!(test.goto_type_definition(), @"No goto target found");
+        assert_snapshot!(test.goto_type_definition(), @r#"
+        info[goto-type-definition]: Type definition
+          --> stdlib/ty_extensions.pyi:20:1
+           |
+        19 | # Types
+        20 | Unknown = object()
+           | ^^^^^^^
+        21 | AlwaysTruthy = object()
+        22 | AlwaysFalsy = object()
+           |
+        info: Source
+         --> main.py:5:12
+          |
+        4 | def function():
+        5 |     global global_var
+          |            ^^^^^^^^^^
+        6 |     global_var = "modified"
+        7 |     return global_var  # Should find the global variable declaration
+          |
+        "#);
     }
 
     #[test]

crates/ty_ide/src/hover.rs

@@ -1704,7 +1704,26 @@ def outer():
         );
 
         // Should find the variable declaration in the outer scope, not the nonlocal statement
-        assert_snapshot!(test.hover(), @"Hover provided no content");
+        assert_snapshot!(test.hover(), @r#"
+        Unknown
+        ---------------------------------------------
+        ```python
+        Unknown
+        ```
+        ---------------------------------------------
+        info[hover]: Hovered content is
+         --> main.py:6:18
+          |
+        5 |     def inner():
+        6 |         nonlocal xy
+          |                  ^-
+          |                  ||
+          |                  |Cursor offset
+          |                  source
+        7 |         xy = "modified"
+        8 |         return x  # Should find the nonlocal x declaration in outer scope
+          |
+        "#);
     }
 
     #[test]
@@ -1756,7 +1775,26 @@ def function():
         );
 
         // Should find the global variable declaration, not the global statement
-        assert_snapshot!(test.hover(), @"Hover provided no content");
+        assert_snapshot!(test.hover(), @r#"
+        Unknown
+        ---------------------------------------------
+        ```python
+        Unknown
+        ```
+        ---------------------------------------------
+        info[hover]: Hovered content is
+         --> main.py:5:12
+          |
+        4 | def function():
+        5 |     global global_var
+          |            ^^^^^^^-^^
+          |            |      |
+          |            |      Cursor offset
+          |            source
+        6 |     global_var = "modified"
+        7 |     return global_var  # Should find the global variable declaration
+          |
+        "#);
     }
 
     #[test]
@@ -1770,7 +1808,26 @@ def function():
             "#,
         );
 
-        assert_snapshot!(test.hover(), @"Hover provided no content");
+        assert_snapshot!(test.hover(), @r#"
+        Unknown
+        ---------------------------------------------
+        ```python
+        Unknown
+        ```
+        ---------------------------------------------
+        info[hover]: Hovered content is
+         --> main.py:4:22
+          |
+        2 | def my_func(command: str):
+        3 |     match command.split():
+        4 |         case ["get", ab]:
+          |                      ^-
+          |                      ||
+          |                      |Cursor offset
+          |                      source
+        5 |             x = ab
+          |
+        "#);
     }
 
     #[test]
@@ -1816,7 +1873,26 @@ def function():
             "#,
         );
 
-        assert_snapshot!(test.hover(), @"Hover provided no content");
+        assert_snapshot!(test.hover(), @r#"
+        Unknown
+        ---------------------------------------------
+        ```python
+        Unknown
+        ```
+        ---------------------------------------------
+        info[hover]: Hovered content is
+         --> main.py:4:23
+          |
+        2 | def my_func(command: str):
+        3 |     match command.split():
+        4 |         case ["get", *ab]:
+          |                       ^-
+          |                       ||
+          |                       |Cursor offset
+          |                       source
+        5 |             x = ab
+          |
+        "#);
     }
 
     #[test]
@@ -1862,7 +1938,26 @@ def function():
             "#,
         );
 
-        assert_snapshot!(test.hover(), @"Hover provided no content");
+        assert_snapshot!(test.hover(), @r#"
+        Unknown
+        ---------------------------------------------
+        ```python
+        Unknown
+        ```
+        ---------------------------------------------
+        info[hover]: Hovered content is
+         --> main.py:4:37
+          |
+        2 | def my_func(command: str):
+        3 |     match command.split():
+        4 |         case ["get", ("a" | "b") as ab]:
+          |                                     ^-
+          |                                     ||
+          |                                     |Cursor offset
+          |                                     source
+        5 |             x = ab
+          |
+        "#);
     }
 
     #[test]
@@ -1914,7 +2009,26 @@ def function():
             "#,
         );
 
-        assert_snapshot!(test.hover(), @"Hover provided no content");
+        assert_snapshot!(test.hover(), @r"
+        Unknown
+        ---------------------------------------------
+        ```python
+        Unknown
+        ```
+        ---------------------------------------------
+        info[hover]: Hovered content is
+          --> main.py:10:30
+           |
+         8 | def my_func(event: Click):
+         9 |     match event:
+        10 |         case Click(x, button=ab):
+           |                              ^-
+           |                              ||
+           |                              |Cursor offset
+           |                              source
+        11 |             x = ab
+           |
+        ");
     }
 
     #[test]
@@ -2011,7 +2125,26 @@ def function():
             "#,
         );
 
-        assert_snapshot!(test.hover(), @"Hover provided no content");
+        assert_snapshot!(test.hover(), @r"
+        Unknown
+        ---------------------------------------------
+        ```python
+        Unknown
+        ```
+        ---------------------------------------------
+        info[hover]: Hovered content is
+          --> main.py:10:23
+           |
+         8 | def my_func(event: Click):
+         9 |     match event:
+        10 |         case Click(x, button=ab):
+           |                       ^^^-^^
+           |                       |  |
+           |                       |  Cursor offset
+           |                       source
+        11 |             x = ab
+           |
+        ");
     }
 
     #[test]

crates/ty_ide/src/importer.rs

@@ -553,6 +553,16 @@ impl<'a> ImportRequest<'a> {
         }
     }
 
+    /// Causes this request to become a command. This will force the
+    /// requested import style, even if another style would be more
+    /// appropriate generally.
+    pub(crate) fn force(mut self) -> Self {
+        Self {
+            force_style: true,
+            ..self
+        }
+    }
+
     /// Attempts to change the import request style so that the chances
     /// of an import conflict are minimized (although not always reduced
     /// to zero).

crates/ty_ide/src/references.rs

@@ -12,7 +12,7 @@
 
 use crate::find_node::CoveringNode;
 use crate::goto::GotoTarget;
-use crate::{Db, NavigationTarget, ReferenceKind, ReferenceTarget};
+use crate::{Db, NavigationTargets, ReferenceKind, ReferenceTarget};
 use ruff_db::files::File;
 use ruff_python_ast::{
     self as ast, AnyNodeRef,
@@ -49,10 +49,9 @@ pub(crate) fn references(
 
     // When finding references, do not resolve any local aliases.
     let model = SemanticModel::new(db, file);
-    let target_definitions_nav = goto_target
+    let target_definitions = goto_target
         .get_definition_targets(&model, ImportAliasResolution::PreserveAliases)?
-        .definition_targets(db)?;
-    let target_definitions: Vec<NavigationTarget> = target_definitions_nav.into_iter().collect();
+        .declaration_targets(db)?;
 
     // Extract the target text from the goto target for fast comparison
     let target_text = goto_target.to_string()?;
@@ -115,7 +114,7 @@ pub(crate) fn references(
 fn references_for_file(
     db: &dyn Db,
     file: File,
-    target_definitions: &[NavigationTarget],
+    target_definitions: &NavigationTargets,
     target_text: &str,
     mode: ReferencesMode,
     references: &mut Vec<ReferenceTarget>,
@@ -159,7 +158,7 @@ fn is_symbol_externally_visible(goto_target: &GotoTarget<'_>) -> bool {
 struct LocalReferencesFinder<'a> {
     model: &'a SemanticModel<'a>,
     tokens: &'a Tokens,
-    target_definitions: &'a [NavigationTarget],
+    target_definitions: &'a NavigationTargets,
     references: &'a mut Vec<ReferenceTarget>,
     mode: ReferencesMode,
     target_text: &'a str,
@@ -318,12 +317,10 @@ impl LocalReferencesFinder<'_> {
             GotoTarget::from_covering_node(self.model, covering_node, offset, self.tokens)
         {
             // Get the definitions for this goto target
-            if let Some(current_definitions_nav) = goto_target
+            if let Some(current_definitions) = goto_target
                 .get_definition_targets(self.model, ImportAliasResolution::PreserveAliases)
                 .and_then(|definitions| definitions.declaration_targets(self.model.db()))
             {
-                let current_definitions: Vec<NavigationTarget> =
-                    current_definitions_nav.into_iter().collect();
                 // Check if any of the current definitions match our target definitions
                 if self.navigation_targets_match(&current_definitions) {
                     // Determine if this is a read or write reference
@@ -337,7 +334,7 @@ impl LocalReferencesFinder<'_> {
     }
 
     /// Check if `Vec<NavigationTarget>` match our target definitions
-    fn navigation_targets_match(&self, current_targets: &[NavigationTarget]) -> bool {
+    fn navigation_targets_match(&self, current_targets: &NavigationTargets) -> bool {
         // Since we're comparing the same symbol, all definitions should be equivalent
         // We only need to check against the first target definition
         if let Some(first_target) = self.target_definitions.iter().next() {

crates/ty_ide/src/rename.rs

@@ -163,7 +163,7 @@ mod tests {
     }
 
     #[test]
-    fn test_prepare_rename_parameter() {
+    fn prepare_rename_parameter() {
         let test = cursor_test(
             "
 def func(<CURSOR>value: int) -> int:
@@ -178,7 +178,7 @@ value = 0
     }
 
     #[test]
-    fn test_rename_parameter() {
+    fn rename_parameter() {
         let test = cursor_test(
             "
 def func(<CURSOR>value: int) -> int:
@@ -207,7 +207,7 @@ func(value=42)
     }
 
     #[test]
-    fn test_rename_function() {
+    fn rename_function() {
         let test = cursor_test(
             "
 def fu<CURSOR>nc():
@@ -235,7 +235,7 @@ x = func
     }
 
     #[test]
-    fn test_rename_class() {
+    fn rename_class() {
         let test = cursor_test(
             "
 class My<CURSOR>Class:
@@ -265,7 +265,7 @@ cls = MyClass
     }
 
     #[test]
-    fn test_rename_invalid_name() {
+    fn rename_invalid_name() {
         let test = cursor_test(
             "
 def fu<CURSOR>nc():
@@ -286,7 +286,7 @@ def fu<CURSOR>nc():
     }
 
     #[test]
-    fn test_multi_file_function_rename() {
+    fn multi_file_function_rename() {
         let test = CursorTest::builder()
             .source(
                 "utils.py",
@@ -312,7 +312,7 @@ from utils import helper_function
 class DataProcessor:
     def __init__(self):
         self.multiplier = helper_function
-    
+
     def process(self, value):
         return helper_function(value)
 ",
@@ -654,7 +654,7 @@ class DataProcessor:
                 def __init__(self, pos, btn):
                     self.position: int = pos
                     self.button: str = btn
-            
+
             def my_func(event: Click):
                 match event:
                     case Click(x, button=a<CURSOR>b):
@@ -685,7 +685,7 @@ class DataProcessor:
                 def __init__(self, pos, btn):
                     self.position: int = pos
                     self.button: str = btn
-            
+
             def my_func(event: Click):
                 match event:
                     case Click(x, button=ab):
@@ -716,7 +716,7 @@ class DataProcessor:
                 def __init__(self, pos, btn):
                     self.position: int = pos
                     self.button: str = btn
-            
+
             def my_func(event: Click):
                 match event:
                     case Cl<CURSOR>ick(x, button=ab):
@@ -756,7 +756,7 @@ class DataProcessor:
                 def __init__(self, pos, btn):
                     self.position: int = pos
                     self.button: str = btn
-            
+
             def my_func(event: Click):
                 match event:
                     case Click(x, but<CURSOR>ton=ab):
@@ -880,7 +880,7 @@ class DataProcessor:
     }
 
     #[test]
-    fn test_cannot_rename_import_module_component() {
+    fn cannot_rename_import_module_component() {
         // Test that we cannot rename parts of module names in import statements
         let test = cursor_test(
             "
@@ -893,7 +893,7 @@ x = os.path.join('a', 'b')
     }
 
     #[test]
-    fn test_cannot_rename_from_import_module_component() {
+    fn cannot_rename_from_import_module_component() {
         // Test that we cannot rename parts of module names in from import statements
         let test = cursor_test(
             "
@@ -906,7 +906,7 @@ result = join('a', 'b')
     }
 
     #[test]
-    fn test_cannot_rename_external_file() {
+    fn cannot_rename_external_file() {
         // This test verifies that we cannot rename a symbol when it's defined in a file
         // that's outside the project (like a standard library function)
         let test = cursor_test(
@@ -920,7 +920,7 @@ x = <CURSOR>os.path.join('a', 'b')
     }
 
     #[test]
-    fn test_rename_alias_at_import_statement() {
+    fn rename_alias_at_import_statement() {
         let test = CursorTest::builder()
             .source(
                 "utils.py",
@@ -931,8 +931,8 @@ def test(): pass
             .source(
                 "main.py",
                 "
-from utils import test as test_<CURSOR>alias
-result = test_alias()
+from utils import test as <CURSOR>alias
+result = alias()
 ",
             )
             .build();
@@ -941,16 +941,16 @@ result = test_alias()
         info[rename]: Rename symbol (found 2 locations)
          --> main.py:2:27
           |
-        2 | from utils import test as test_alias
-          |                           ^^^^^^^^^^
-        3 | result = test_alias()
-          |          ----------
+        2 | from utils import test as alias
+          |                           ^^^^^
+        3 | result = alias()
+          |          -----
           |
         ");
     }
 
     #[test]
-    fn test_rename_alias_at_usage_site() {
+    fn rename_alias_at_usage_site() {
         // Test renaming an alias when the cursor is on the alias in the usage statement
         let test = CursorTest::builder()
             .source(
@@ -962,8 +962,8 @@ def test(): pass
             .source(
                 "main.py",
                 "
-from utils import test as test_alias
-result = test_<CURSOR>alias()
+from utils import test as alias
+result = <CURSOR>alias()
 ",
             )
             .build();
@@ -972,16 +972,16 @@ result = test_<CURSOR>alias()
         info[rename]: Rename symbol (found 2 locations)
          --> main.py:2:27
           |
-        2 | from utils import test as test_alias
-          |                           ^^^^^^^^^^
-        3 | result = test_alias()
-          |          ----------
+        2 | from utils import test as alias
+          |                           ^^^^^
+        3 | result = alias()
+          |          -----
           |
         ");
     }
 
     #[test]
-    fn test_rename_across_import_chain_with_mixed_aliases() {
+    fn rename_across_import_chain_with_mixed_aliases() {
         // Test renaming a symbol that's imported across multiple files with mixed alias patterns
         // File 1 (source.py): defines the original function
         // File 2 (middle.py): imports without alias from source.py
@@ -1049,7 +1049,7 @@ value1 = func_alias()
     }
 
     #[test]
-    fn test_rename_alias_in_import_chain() {
+    fn rename_alias_in_import_chain() {
         let test = CursorTest::builder()
             .source(
                 "file1.py",
@@ -1101,7 +1101,7 @@ class App:
     }
 
     #[test]
-    fn test_cannot_rename_keyword() {
+    fn cannot_rename_keyword() {
         // Test that we cannot rename Python keywords like "None"
         let test = cursor_test(
             "
@@ -1116,7 +1116,7 @@ def process_value(value):
     }
 
     #[test]
-    fn test_cannot_rename_builtin_type() {
+    fn cannot_rename_builtin_type() {
         // Test that we cannot rename Python builtin types like "int"
         let test = cursor_test(
             "
@@ -1129,7 +1129,7 @@ def convert_to_number(value):
     }
 
     #[test]
-    fn test_rename_keyword_argument() {
+    fn rename_keyword_argument() {
         // Test renaming a keyword argument and its corresponding parameter
         let test = cursor_test(
             "
@@ -1156,7 +1156,7 @@ result = func(10, <CURSOR>y=20)
     }
 
     #[test]
-    fn test_rename_parameter_with_keyword_argument() {
+    fn rename_parameter_with_keyword_argument() {
         // Test renaming a parameter and its corresponding keyword argument
         let test = cursor_test(
             "
@@ -1181,4 +1181,64 @@ result = func(10, y=20)
           |
         ");
     }
+
+    #[test]
+    fn import_alias() {
+        let test = CursorTest::builder()
+            .source(
+                "main.py",
+                r#"
+                import warnings
+                import warnings as <CURSOR>abc
+
+                x = abc
+                y = warnings
+            "#,
+            )
+            .build();
+
+        assert_snapshot!(test.rename("z"), @r"
+        info[rename]: Rename symbol (found 2 locations)
+         --> main.py:3:20
+          |
+        2 | import warnings
+        3 | import warnings as abc
+          |                    ^^^
+        4 |
+        5 | x = abc
+          |     ---
+        6 | y = warnings
+          |
+        ");
+    }
+
+    #[test]
+    fn import_alias_use() {
+        let test = CursorTest::builder()
+            .source(
+                "main.py",
+                r#"
+                import warnings
+                import warnings as abc
+
+                x = abc<CURSOR>
+                y = warnings
+            "#,
+            )
+            .build();
+
+        assert_snapshot!(test.rename("z"), @r"
+        info[rename]: Rename symbol (found 2 locations)
+         --> main.py:3:20
+          |
+        2 | import warnings
+        3 | import warnings as abc
+          |                    ^^^
+        4 |
+        5 | x = abc
+          |     ---
+        6 | y = warnings
+          |
+        ");
+    }
 }

crates/ty_python_semantic/resources/mdtest/annotations/generic_alias.md

@@ -0,0 +1,34 @@
+# GenericAlias in type expressions
+
+We recognize if a `types.GenericAlias` instance is created by specializing a generic class. We don't
+explicitly mention it in our type display, but `list[int]` in the example below is a `GenericAlias`
+instance at runtime:
+
+```py
+Numbers = list[int]
+
+# At runtime, `Numbers` is an instance of `types.GenericAlias`. Showing
+# this as `list[int]` is more helpful, though:
+reveal_type(Numbers)  # revealed: <class 'list[int]'>
+
+def _(numbers: Numbers) -> None:
+    reveal_type(numbers)  # revealed: list[int]
+```
+
+It is also valid to create `GenericAlias` instances manually:
+
+```py
+from types import GenericAlias
+
+Strings = GenericAlias(list, (str,))
+
+reveal_type(Strings)  # revealed: GenericAlias
+```
+
+However, using such a `GenericAlias` instance in a type expression is currently not supported:
+
+```py
+# error: [invalid-type-form] "Variable of type `GenericAlias` is not allowed in a type expression"
+def _(strings: Strings) -> None:
+    reveal_type(strings)  # revealed: Unknown
+```

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

@@ -1,24 +1,16 @@
 # NewType
 
-## Valid forms
+## Basic usage
+
+`NewType` can be used to create distinct types that are based on existing types:
 
 ```py
 from typing_extensions import NewType
-from types import GenericAlias
 
-X = GenericAlias(type, ())
-A = NewType("A", int)
-# TODO: typeshed for `typing.GenericAlias` uses `type` for the first argument. `NewType` should be special-cased
-# to be compatible with `type`
-# error: [invalid-argument-type] "Argument to function `__new__` is incorrect: Expected `type`, found `<NewType pseudo-class 'A'>`"
-B = GenericAlias(A, ())
+UserId = NewType("UserId", int)
 
-def _(
-    a: A,
-    b: B,
-):
-    reveal_type(a)  # revealed: A
-    reveal_type(b)  # revealed: @Todo(Support for `typing.GenericAlias` instances in type expressions)
+def _(user_id: UserId):
+    reveal_type(user_id)  # revealed: UserId
 ```
 
 ## Subtyping

crates/ty_python_semantic/resources/mdtest/cycle.md

@@ -52,6 +52,10 @@ def f(x: A):
 
 JSONPrimitive = Union[str, int, float, bool, None]
 JSONValue = TypeAliasType("JSONValue", 'Union[JSONPrimitive, Sequence["JSONValue"], Mapping[str, "JSONValue"]]')
+
+def _(x: JSONValue):
+    # TODO: should be `JSONValue`
+    reveal_type(x)  # revealed: Divergent
 ```
 
 ## Self-referential legacy type variables

crates/ty_python_semantic/resources/mdtest/exhaustiveness_checking.md

@@ -284,10 +284,17 @@ python-version = "3.12"
 ```py
 from typing import assert_never
 
-class A[T]: ...
+class A[T]:
+    value: T
+
 class ASub[T](A[T]): ...
-class B[T]: ...
-class C[T]: ...
+
+class B[T]:
+    value: T
+
+class C[T]:
+    value: T
+
 class D: ...
 class E: ...
 class F: ...

crates/ty_python_semantic/resources/mdtest/final.md

@@ -51,6 +51,10 @@ class Parent:
     @final
     def my_property2(self) -> int: ...
 
+    @property
+    @final
+    def my_property3(self) -> int: ...
+
     @final
     @classmethod
     def class_method1(cls) -> int: ...
@@ -86,6 +90,13 @@ class Child(Parent):
 
     @property
     def my_property2(self) -> int: ...  # error: [override-of-final-method]
+    @my_property2.setter
+    def my_property2(self, x: int) -> None: ...
+
+    @property
+    def my_property3(self) -> int: ...  # error: [override-of-final-method]
+    @my_property3.deleter
+    def my_proeprty3(self) -> None: ...
 
     @classmethod
     def class_method1(cls) -> int: ...  # error: [override-of-final-method]
@@ -230,7 +241,7 @@ class ChildOfBad(Bad):
     def bar(self, x: str) -> str: ...
     @overload
     def bar(self, x: int) -> int: ...  # error: [override-of-final-method]
-    
+
     @overload
     def baz(self, x: str) -> str: ...
     @overload
@@ -461,14 +472,17 @@ class B(A):
     def method1(self) -> None: ...  # error: [override-of-final-method]
     def method2(self) -> None: ...  # error: [override-of-final-method]
     def method3(self) -> None: ...  # error: [override-of-final-method]
-    def method4(self) -> None: ...  # error: [override-of-final-method]
+
+    # check that autofixes don't introduce invalid syntax
+    # if there are multiple statements on one line
+    #
+    # TODO: we should emit a Liskov violation here too
+    # error: [override-of-final-method]
+    method4 = 42; unrelated = 56  # fmt: skip
 
 # Possible overrides of possibly `@final` methods...
 class C(A):
     if coinflip():
-        # TODO: the autofix here introduces invalid syntax because there are now no
-        # statements inside the `if:` branch
-        # (but it might still be a useful autofix in an IDE context?)
         def method1(self) -> None: ...  # error: [override-of-final-method]
     else:
         pass

crates/ty_python_semantic/resources/mdtest/generics/legacy/classes.md

@@ -5,6 +5,11 @@
 At its simplest, to define a generic class using the legacy syntax, you inherit from the
 `typing.Generic` special form, which is "specialized" with the generic class's type variables.
 
+```toml
+[environment]
+python-version = "3.11"
+```
+
 ```py
 from ty_extensions import generic_context
 from typing_extensions import Generic, TypeVar, TypeVarTuple, ParamSpec, Unpack
@@ -19,7 +24,9 @@ class MultipleTypevars(Generic[T, S]): ...
 class SingleParamSpec(Generic[P]): ...
 class TypeVarAndParamSpec(Generic[P, T]): ...
 class SingleTypeVarTuple(Generic[Unpack[Ts]]): ...
+class StarredSingleTypeVarTuple(Generic[*Ts]): ...
 class TypeVarAndTypeVarTuple(Generic[T, Unpack[Ts]]): ...
+class StarredTypeVarAndTypeVarTuple(Generic[T, *Ts]): ...
 
 # revealed: ty_extensions.GenericContext[T@SingleTypevar]
 reveal_type(generic_context(SingleTypevar))
@@ -34,6 +41,8 @@ reveal_type(generic_context(TypeVarAndParamSpec))
 # TODO: support `TypeVarTuple` properly (these should not reveal `None`)
 reveal_type(generic_context(SingleTypeVarTuple))  # revealed: None
 reveal_type(generic_context(TypeVarAndTypeVarTuple))  # revealed: None
+reveal_type(generic_context(StarredSingleTypeVarTuple))  # revealed: None
+reveal_type(generic_context(StarredTypeVarAndTypeVarTuple))  # revealed: None
 ```
 
 Inheriting from `Generic` multiple times yields a `duplicate-base` diagnostic, just like any other
@@ -210,6 +219,37 @@ reveal_type(WithDefault[str, str]())  # revealed: WithDefault[str, str]
 reveal_type(WithDefault[str]())  # revealed: WithDefault[str, int]
 ```
 
+## Diagnostics for bad specializations
+
+We show the user where the type variable was defined if a specialization is given that doesn't
+satisfy the type variable's upper bound or constraints:
+
+<!-- snapshot-diagnostics -->
+
+`library.py`:
+
+```py
+from typing import TypeVar, Generic
+
+T = TypeVar("T", bound=str)
+U = TypeVar("U", int, bytes)
+
+class Bounded(Generic[T]):
+    x: T
+
+class Constrained(Generic[U]):
+    x: U
+```
+
+`main.py`:
+
+```py
+from library import Bounded, Constrained
+
+x: Bounded[int]  # error: [invalid-type-arguments]
+y: Constrained[str]  # error: [invalid-type-arguments]
+```
+
 ## Inferring generic class parameters
 
 We can infer the type parameter from a type context:

crates/ty_python_semantic/resources/mdtest/generics/legacy/paramspec.md

@@ -1,4 +1,4 @@
-# `ParamSpec`
+# Legacy `ParamSpec`
 
 ## Definition
 
@@ -115,59 +115,3 @@ P = ParamSpec("P", default=[A, B])
 class A: ...
 class B: ...
 ```
-
-### PEP 695
-
-```toml
-[environment]
-python-version = "3.12"
-```
-
-#### Valid
-
-```py
-def foo1[**P]() -> None:
-    reveal_type(P)  # revealed: typing.ParamSpec
-
-def foo2[**P = ...]() -> None:
-    reveal_type(P)  # revealed: typing.ParamSpec
-
-def foo3[**P = [int, str]]() -> None:
-    reveal_type(P)  # revealed: typing.ParamSpec
-
-def foo4[**P, **Q = P]():
-    reveal_type(P)  # revealed: typing.ParamSpec
-    reveal_type(Q)  # revealed: typing.ParamSpec
-```
-
-#### Invalid
-
-ParamSpec, when defined using the new syntax, does not allow defining bounds or constraints.
-
-This results in a lot of syntax errors mainly because the AST doesn't accept them in this position.
-The parser could do a better job in recovering from these errors.
-
-<!-- blacken-docs:off -->
-
-```py
-# error: [invalid-syntax]
-# error: [invalid-syntax]
-# error: [invalid-syntax]
-# error: [invalid-syntax]
-# error: [invalid-syntax]
-# error: [invalid-syntax]
-def foo[**P: int]() -> None:
-    # error: [invalid-syntax]
-    # error: [invalid-syntax]
-    pass
-```
-
-<!-- blacken-docs:on -->
-
-#### Invalid default
-
-```py
-# error: [invalid-paramspec]
-def foo[**P = int]() -> None:
-    pass
-```

crates/ty_python_semantic/resources/mdtest/generics/pep695/classes.md

@@ -191,6 +191,32 @@ reveal_type(WithDefault[str, str]())  # revealed: WithDefault[str, str]
 reveal_type(WithDefault[str]())  # revealed: WithDefault[str, int]
 ```
 
+## Diagnostics for bad specializations
+
+We show the user where the type variable was defined if a specialization is given that doesn't
+satisfy the type variable's upper bound or constraints:
+
+<!-- snapshot-diagnostics -->
+
+`library.py`:
+
+```py
+class Bounded[T: str]:
+    x: T
+
+class Constrained[U: (int, bytes)]:
+    x: U
+```
+
+`main.py`:
+
+```py
+from library import Bounded, Constrained
+
+x: Bounded[int]  # error: [invalid-type-arguments]
+y: Constrained[str]  # error: [invalid-type-arguments]
+```
+
 ## Inferring generic class parameters
 
 We can infer the type parameter from a type context:

crates/ty_python_semantic/resources/mdtest/generics/pep695/paramspec.md

@@ -0,0 +1,64 @@
+# PEP 695 `ParamSpec`
+
+`ParamSpec` was introduced in Python 3.12 while the support for specifying defaults was added in
+Python 3.13.
+
+```toml
+[environment]
+python-version = "3.13"
+```
+
+## Definition
+
+```py
+def foo1[**P]() -> None:
+    reveal_type(P)  # revealed: typing.ParamSpec
+```
+
+## Bounds and constraints
+
+`ParamSpec`, when defined using the new syntax, does not allow defining bounds or constraints.
+
+TODO: This results in a lot of syntax errors mainly because the AST doesn't accept them in this
+position. The parser could do a better job in recovering from these errors.
+
+<!-- blacken-docs:off -->
+
+```py
+# error: [invalid-syntax]
+# error: [invalid-syntax]
+# error: [invalid-syntax]
+# error: [invalid-syntax]
+# error: [invalid-syntax]
+# error: [invalid-syntax]
+def foo[**P: int]() -> None:
+    # error: [invalid-syntax]
+    # error: [invalid-syntax]
+    pass
+```
+
+<!-- blacken-docs:on -->
+
+## Default
+
+The default value for a `ParamSpec` can be either a list of types, `...`, or another `ParamSpec`.
+
+```py
+def foo2[**P = ...]() -> None:
+    reveal_type(P)  # revealed: typing.ParamSpec
+
+def foo3[**P = [int, str]]() -> None:
+    reveal_type(P)  # revealed: typing.ParamSpec
+
+def foo4[**P, **Q = P]():
+    reveal_type(P)  # revealed: typing.ParamSpec
+    reveal_type(Q)  # revealed: typing.ParamSpec
+```
+
+Other values are invalid.
+
+```py
+# error: [invalid-paramspec]
+def foo[**P = int]() -> None:
+    pass
+```

crates/ty_python_semantic/resources/mdtest/generics/specialize_constrained.md

@@ -321,9 +321,8 @@ from typing import Never
 from ty_extensions import ConstraintSet, generic_context
 
 def mentions[T, U]():
+    # (T@mentions ≤ int) ∧ (U@mentions = list[T@mentions])
     constraints = ConstraintSet.range(Never, T, int) & ConstraintSet.range(list[T], U, list[T])
-    # revealed: ty_extensions.ConstraintSet[((T@mentions ≤ int) ∧ (U@mentions = list[T@mentions]))]
-    reveal_type(constraints)
     # revealed: ty_extensions.Specialization[T@mentions = int, U@mentions = list[int]]
     reveal_type(generic_context(mentions).specialize_constrained(constraints))
 ```
@@ -334,9 +333,8 @@ this case.
 
 ```py
 def divergent[T, U]():
+    # (T@divergent = list[U@divergent]) ∧ (U@divergent = list[T@divergent]))
     constraints = ConstraintSet.range(list[U], T, list[U]) & ConstraintSet.range(list[T], U, list[T])
-    # revealed: ty_extensions.ConstraintSet[((T@divergent = list[U@divergent]) ∧ (U@divergent = list[T@divergent]))]
-    reveal_type(constraints)
     # revealed: None
     reveal_type(generic_context(divergent).specialize_constrained(constraints))
 ```

crates/ty_python_semantic/resources/mdtest/import/workspaces.md

@@ -0,0 +1,660 @@
+# Support for Resolving Imports In Workspaces
+
+Python packages have fairly rigid structures that we rely on when resolving imports and merging
+namespace packages or stub packages. These rules go out the window when analyzing some random local
+python file in some random workspace, and so we need to be more tolerant of situations that wouldn't
+fly in a published package, cases where we're not configured as well as we'd like, or cases where
+two projects in a monorepo have conflicting definitions (but we want to analyze both at once).
+
+## Invalid Names
+
+While you can't syntactically refer to a module with an invalid name (i.e. one with a `-`, or that
+has the same name as a keyword) there are plenty of situations where a module with an invalid name
+can be run. For instance `python my-script.py` and `python my-proj/main.py` both work, even though
+we might in the course of analyzing the code compute the module name `my-script` or `my-proj.main`.
+
+Also, a sufficiently motivated programmer can technically use `importlib.import_module` which takes
+strings and does in fact allow syntactically invalid module names.
+
+### Current File Is Invalid Module Name
+
+Relative and absolute imports should resolve fine in a file that isn't a valid module name.
+
+`my-main.py`:
+
+```py
+# TODO: there should be no errors in this file
+
+# error: [unresolved-import]
+from .mod1 import x
+
+# error: [unresolved-import]
+from . import mod2
+import mod3
+
+reveal_type(x)  # revealed: Unknown
+reveal_type(mod2.y)  # revealed: Unknown
+reveal_type(mod3.z)  # revealed: int
+```
+
+`mod1.py`:
+
+```py
+x: int = 1
+```
+
+`mod2.py`:
+
+```py
+y: int = 2
+```
+
+`mod3.py`:
+
+```py
+z: int = 2
+```
+
+### Current Directory Is Invalid Module Name
+
+Relative and absolute imports should resolve fine in a dir that isn't a valid module name.
+
+`my-tests/main.py`:
+
+```py
+# TODO: there should be no errors in this file
+
+# error: [unresolved-import]
+from .mod1 import x
+
+# error: [unresolved-import]
+from . import mod2
+import mod3
+
+reveal_type(x)  # revealed: Unknown
+reveal_type(mod2.y)  # revealed: Unknown
+reveal_type(mod3.z)  # revealed: int
+```
+
+`my-tests/mod1.py`:
+
+```py
+x: int = 1
+```
+
+`my-tests/mod2.py`:
+
+```py
+y: int = 2
+```
+
+`mod3.py`:
+
+```py
+z: int = 2
+```
+
+### Current Directory Is Invalid Package Name
+
+Relative and absolute imports should resolve fine in a dir that isn't a valid package name, even if
+it contains an `__init__.py`:
+
+`my-tests/__init__.py`:
+
+```py
+```
+
+`my-tests/main.py`:
+
+```py
+# TODO: there should be no errors in this file
+
+# error: [unresolved-import]
+from .mod1 import x
+
+# error: [unresolved-import]
+from . import mod2
+import mod3
+
+reveal_type(x)  # revealed: Unknown
+reveal_type(mod2.y)  # revealed: Unknown
+reveal_type(mod3.z)  # revealed: int
+```
+
+`my-tests/mod1.py`:
+
+```py
+x: int = 1
+```
+
+`my-tests/mod2.py`:
+
+```py
+y: int = 2
+```
+
+`mod3.py`:
+
+```py
+z: int = 2
+```
+
+## Multiple Projects
+
+It's common for a monorepo to define many separate projects that may or may not depend on eachother
+and are stitched together with a package manager like `uv` or `poetry`, often as editables. In this
+case, especially when running as an LSP, we want to be able to analyze all of the projects at once,
+allowing us to reuse results between projects, without getting confused about things that only make
+sense when analyzing the project separately.
+
+The following tests will feature two projects, `a` and `b` where the "real" packages are found under
+`src/` subdirectories (and we've been configured to understand that), but each project also contains
+other python files in their roots or subdirectories that contains python files which relatively
+import eachother and also absolutely import the main package of the project. All of these imports
+*should* resolve.
+
+Often the fact that there is both an `a` and `b` project seemingly won't matter, but many possible
+solutions will misbehave under these conditions, as e.g. if both define a `main.py` and test code
+has `import main`, we need to resolve each project's main as appropriate.
+
+One key hint we will have in these situations is the existence of a `pyproject.toml`, so the
+following examples include them in case they help.
+
+### Tests Directory With Overlapping Names
+
+Here we have fairly typical situation where there are two projects `aproj` and `bproj` where the
+"real" packages are found under `src/` subdirectories, but each project also contains a `tests/`
+directory that contains python files which relatively import eachother and also absolutely import
+the package they test. All of these imports *should* resolve.
+
+```toml
+[environment]
+# This is similar to what we would compute for installed editables
+extra-paths = ["aproj/src/", "bproj/src/"]
+```
+
+`aproj/tests/test1.py`:
+
+```py
+from .setup import x
+from . import setup
+from a import y
+import a
+
+reveal_type(x)  # revealed: int
+reveal_type(setup.x)  # revealed: int
+reveal_type(y)  # revealed: int
+reveal_type(a.y)  # revealed: int
+```
+
+`aproj/tests/setup.py`:
+
+```py
+x: int = 1
+```
+
+`aproj/pyproject.toml`:
+
+```text
+name = "a"
+version = "0.1.0"
+```
+
+`aproj/src/a/__init__.py`:
+
+```py
+y: int = 10
+```
+
+`bproj/tests/test1.py`:
+
+```py
+from .setup import x
+from . import setup
+from b import y
+import b
+
+reveal_type(x)  # revealed: str
+reveal_type(setup.x)  # revealed: str
+reveal_type(y)  # revealed: str
+reveal_type(b.y)  # revealed: str
+```
+
+`bproj/tests/setup.py`:
+
+```py
+x: str = "2"
+```
+
+`bproj/pyproject.toml`:
+
+```text
+name = "a"
+version = "0.1.0"
+```
+
+`bproj/src/b/__init__.py`:
+
+```py
+y: str = "20"
+```
+
+### Tests Directory With Ambiguous Project Directories
+
+The same situation as the previous test but instead of the project `a` being in a directory `aproj`
+to disambiguate, we now need to avoid getting confused about whether `a/` or `a/src/a/` is the
+package `a` while still resolving imports.
+
+```toml
+[environment]
+# This is similar to what we would compute for installed editables
+extra-paths = ["a/src/", "b/src/"]
+```
+
+`a/tests/test1.py`:
+
+```py
+# TODO: there should be no errors in this file.
+
+# error: [unresolved-import]
+from .setup import x
+
+# error: [unresolved-import]
+from . import setup
+from a import y
+import a
+
+reveal_type(x)  # revealed: Unknown
+reveal_type(setup.x)  # revealed: Unknown
+reveal_type(y)  # revealed: int
+reveal_type(a.y)  # revealed: int
+```
+
+`a/tests/setup.py`:
+
+```py
+x: int = 1
+```
+
+`a/pyproject.toml`:
+
+```text
+name = "a"
+version = "0.1.0"
+```
+
+`a/src/a/__init__.py`:
+
+```py
+y: int = 10
+```
+
+`b/tests/test1.py`:
+
+```py
+# TODO: there should be no errors in this file
+
+# error: [unresolved-import]
+from .setup import x
+
+# error: [unresolved-import]
+from . import setup
+from b import y
+import b
+
+reveal_type(x)  # revealed: Unknown
+reveal_type(setup.x)  # revealed: Unknown
+reveal_type(y)  # revealed: str
+reveal_type(b.y)  # revealed: str
+```
+
+`b/tests/setup.py`:
+
+```py
+x: str = "2"
+```
+
+`b/pyproject.toml`:
+
+```text
+name = "a"
+version = "0.1.0"
+```
+
+`b/src/b/__init__.py`:
+
+```py
+y: str = "20"
+```
+
+### Tests Package With Ambiguous Project Directories
+
+The same situation as the previous test but `tests/__init__.py` is also defined, in case that
+complicates the situation.
+
+```toml
+[environment]
+extra-paths = ["a/src/", "b/src/"]
+```
+
+`a/tests/test1.py`:
+
+```py
+# TODO: there should be no errors in this file.
+
+# error: [unresolved-import]
+from .setup import x
+
+# error: [unresolved-import]
+from . import setup
+from a import y
+import a
+
+reveal_type(x)  # revealed: Unknown
+reveal_type(setup.x)  # revealed: Unknown
+reveal_type(y)  # revealed: int
+reveal_type(a.y)  # revealed: int
+```
+
+`a/tests/__init__.py`:
+
+```py
+```
+
+`a/tests/setup.py`:
+
+```py
+x: int = 1
+```
+
+`a/pyproject.toml`:
+
+```text
+name = "a"
+version = "0.1.0"
+```
+
+`a/src/a/__init__.py`:
+
+```py
+y: int = 10
+```
+
+`b/tests/test1.py`:
+
+```py
+# TODO: there should be no errors in this file
+
+# error: [unresolved-import]
+from .setup import x
+
+# error: [unresolved-import]
+from . import setup
+from b import y
+import b
+
+reveal_type(x)  # revealed: Unknown
+reveal_type(setup.x)  # revealed: Unknown
+reveal_type(y)  # revealed: str
+reveal_type(b.y)  # revealed: str
+```
+
+`b/tests/__init__.py`:
+
+```py
+```
+
+`b/tests/setup.py`:
+
+```py
+x: str = "2"
+```
+
+`b/pyproject.toml`:
+
+```text
+name = "a"
+version = "0.1.0"
+```
+
+`b/src/b/__init__.py`:
+
+```py
+y: str = "20"
+```
+
+### Tests Directory Absolute Importing `main.py`
+
+Here instead of defining packages we have a couple simple applications with a `main.py` and tests
+that `import main` and expect that to work.
+
+`a/tests/test1.py`:
+
+```py
+# TODO: there should be no errors in this file.
+
+from .setup import x
+from . import setup
+
+# error: [unresolved-import]
+from main import y
+
+# error: [unresolved-import]
+import main
+
+reveal_type(x)  # revealed: int
+reveal_type(setup.x)  # revealed: int
+reveal_type(y)  # revealed: Unknown
+reveal_type(main.y)  # revealed: Unknown
+```
+
+`a/tests/setup.py`:
+
+```py
+x: int = 1
+```
+
+`a/pyproject.toml`:
+
+```text
+name = "a"
+version = "0.1.0"
+```
+
+`a/main.py`:
+
+```py
+y: int = 10
+```
+
+`b/tests/test1.py`:
+
+```py
+# TODO: there should be no errors in this file
+
+from .setup import x
+from . import setup
+
+# error: [unresolved-import]
+from main import y
+
+# error: [unresolved-import]
+import main
+
+reveal_type(x)  # revealed: str
+reveal_type(setup.x)  # revealed: str
+reveal_type(y)  # revealed: Unknown
+reveal_type(main.y)  # revealed: Unknown
+```
+
+`b/tests/setup.py`:
+
+```py
+x: str = "2"
+```
+
+`b/pyproject.toml`:
+
+```text
+name = "a"
+version = "0.1.0"
+```
+
+`b/main.py`:
+
+```py
+y: str = "20"
+```
+
+### Tests Package Absolute Importing `main.py`
+
+The same as the previous case but `tests/__init__.py` exists in case that causes different issues.
+
+`a/tests/test1.py`:
+
+```py
+# TODO: there should be no errors in this file.
+
+from .setup import x
+from . import setup
+
+# error: [unresolved-import]
+from main import y
+
+# error: [unresolved-import]
+import main
+
+reveal_type(x)  # revealed: int
+reveal_type(setup.x)  # revealed: int
+reveal_type(y)  # revealed: Unknown
+reveal_type(main.y)  # revealed: Unknown
+```
+
+`a/tests/__init__.py`:
+
+```py
+```
+
+`a/tests/setup.py`:
+
+```py
+x: int = 1
+```
+
+`a/pyproject.toml`:
+
+```text
+name = "a"
+version = "0.1.0"
+```
+
+`a/main.py`:
+
+```py
+y: int = 10
+```
+
+`b/tests/test1.py`:
+
+```py
+# TODO: there should be no errors in this file
+
+from .setup import x
+from . import setup
+
+# error: [unresolved-import]
+from main import y
+
+# error: [unresolved-import]
+import main
+
+reveal_type(x)  # revealed: str
+reveal_type(setup.x)  # revealed: str
+reveal_type(y)  # revealed: Unknown
+reveal_type(main.y)  # revealed: Unknown
+```
+
+`b/tests/__init__.py`:
+
+```py
+```
+
+`b/tests/setup.py`:
+
+```py
+x: str = "2"
+```
+
+`b/pyproject.toml`:
+
+```text
+name = "a"
+version = "0.1.0"
+```
+
+`b/main.py`:
+
+```py
+y: str = "20"
+```
+
+### `main.py` absolute importing private package
+
+In this case each project has a `main.py` that defines a "private" `utils` package and absolute
+imports it.
+
+`a/main.py`:
+
+```py
+# TODO: there should be no errors in this file.
+
+# error: [unresolved-import]
+from utils import x
+
+# error: [unresolved-import]
+import utils
+
+reveal_type(x)  # revealed: Unknown
+reveal_type(utils.x)  # revealed: Unknown
+```
+
+`a/utils/__init__.py`:
+
+```py
+x: int = 1
+```
+
+`a/pyproject.toml`:
+
+```text
+name = "a"
+version = "0.1.0"
+```
+
+`b/main.py`:
+
+```py
+# TODO: there should be no errors in this file.
+
+# error: [unresolved-import]
+from utils import x
+
+# error: [unresolved-import]
+import utils
+
+reveal_type(x)  # revealed: Unknown
+reveal_type(utils.x)  # revealed: Unknown
+```
+
+`b/utils/__init__.py`:
+
+```py
+x: str = "2"
+```
+
+`b/pyproject.toml`:
+
+```text
+name = "a"
+version = "0.1.0"
+```

crates/ty_python_semantic/resources/mdtest/named_tuple.md

@@ -408,3 +408,205 @@ class Vec2(NamedTuple):
 
 Vec2(0.0, 0.0)
 ```
+
+## `super()` is not supported in NamedTuple methods
+
+Using `super()` in a method of a `NamedTuple` class will raise an exception at runtime. In Python
+3.14+, a `TypeError` is raised; in earlier versions, a confusing `RuntimeError` about
+`__classcell__` is raised.
+
+```py
+from typing import NamedTuple
+
+class F(NamedTuple):
+    x: int
+
+    def method(self):
+        # error: [super-call-in-named-tuple-method] "Cannot use `super()` in a method of NamedTuple class `F`"
+        super()
+
+    def method_with_args(self):
+        # error: [super-call-in-named-tuple-method] "Cannot use `super()` in a method of NamedTuple class `F`"
+        super(F, self)
+
+    def method_with_different_pivot(self):
+        # Even passing a different pivot class fails.
+        # error: [super-call-in-named-tuple-method] "Cannot use `super()` in a method of NamedTuple class `F`"
+        super(tuple, self)
+
+    @classmethod
+    def class_method(cls):
+        # error: [super-call-in-named-tuple-method] "Cannot use `super()` in a method of NamedTuple class `F`"
+        super()
+
+    @staticmethod
+    def static_method():
+        # error: [super-call-in-named-tuple-method] "Cannot use `super()` in a method of NamedTuple class `F`"
+        super()
+
+    @property
+    def prop(self):
+        # error: [super-call-in-named-tuple-method] "Cannot use `super()` in a method of NamedTuple class `F`"
+        return super()
+```
+
+However, classes that **inherit from** a `NamedTuple` class (but don't directly inherit from
+`NamedTuple`) can use `super()` normally:
+
+```py
+from typing import NamedTuple
+
+class Base(NamedTuple):
+    x: int
+
+class Child(Base):
+    def method(self):
+        super()
+```
+
+And regular classes that don't inherit from `NamedTuple` at all can use `super()` as normal:
+
+```py
+class Regular:
+    def method(self):
+        super()  # fine
+```
+
+Using `super()` on a `NamedTuple` class also works fine if it occurs outside the class:
+
+```py
+from typing import NamedTuple
+
+class F(NamedTuple):
+    x: int
+
+super(F, F(42))  # fine
+```
+
+## NamedTuples cannot have field names starting with underscores
+
+<!-- snapshot-diagnostics -->
+
+```py
+from typing import NamedTuple
+
+class Foo(NamedTuple):
+    # error: [invalid-named-tuple] "NamedTuple field `_bar` cannot start with an underscore"
+    _bar: int
+
+class Bar(NamedTuple):
+    x: int
+
+class Baz(Bar):
+    _whatever: str  # `Baz` is not a NamedTuple class, so this is fine
+```
+
+## Prohibited NamedTuple attributes
+
+`NamedTuple` classes have certain synthesized attributes that cannot be overwritten. Attempting to
+assign to these attributes (without type annotations) will raise an `AttributeError` at runtime.
+
+```py
+from typing import NamedTuple
+
+class F(NamedTuple):
+    x: int
+
+    # error: [invalid-named-tuple] "Cannot overwrite NamedTuple attribute `_asdict`"
+    _asdict = 42
+
+    # error: [invalid-named-tuple] "Cannot overwrite NamedTuple attribute `_make`"
+    _make = "foo"
+
+    # error: [invalid-named-tuple] "Cannot overwrite NamedTuple attribute `_replace`"
+    _replace = lambda self: self
+
+    # error: [invalid-named-tuple] "Cannot overwrite NamedTuple attribute `_fields`"
+    _fields = ()
+
+    # error: [invalid-named-tuple] "Cannot overwrite NamedTuple attribute `_field_defaults`"
+    _field_defaults = {}
+
+    # error: [invalid-named-tuple] "Cannot overwrite NamedTuple attribute `__new__`"
+    __new__ = None
+
+    # error: [invalid-named-tuple] "Cannot overwrite NamedTuple attribute `__init__`"
+    __init__ = None
+
+    # error: [invalid-named-tuple] "Cannot overwrite NamedTuple attribute `__getnewargs__`"
+    __getnewargs__ = None
+```
+
+However, other attributes (including those starting with underscores) can be assigned without error:
+
+```py
+from typing import NamedTuple
+
+class G(NamedTuple):
+    x: int
+
+    # These are fine (not prohibited attributes)
+    _custom = 42
+    __custom__ = "ok"
+    regular_attr = "value"
+```
+
+Note that type-annotated attributes become NamedTuple fields, not attribute overrides. They are not
+flagged as prohibited attribute overrides (though field names starting with `_` are caught by the
+underscore field name check):
+
+```py
+from typing import NamedTuple
+
+class H(NamedTuple):
+    x: int
+    # This is a field declaration, not an override. It's not flagged as an override,
+    # but is flagged because field names cannot start with underscores.
+    # error: [invalid-named-tuple] "NamedTuple field `_asdict` cannot start with an underscore"
+    _asdict: int = 0
+```
+
+The check also applies to assignments within conditional blocks:
+
+```py
+from typing import NamedTuple
+
+class I(NamedTuple):
+    x: int
+
+    if True:
+        # error: [invalid-named-tuple] "Cannot overwrite NamedTuple attribute `_asdict`"
+        _asdict = 42
+```
+
+Method definitions with prohibited names are also flagged:
+
+```py
+from typing import NamedTuple
+
+class J(NamedTuple):
+    x: int
+
+    # error: [invalid-named-tuple] "Cannot overwrite NamedTuple attribute `_asdict`"
+    def _asdict(self):
+        return {}
+
+    @classmethod
+    # error: [invalid-named-tuple] "Cannot overwrite NamedTuple attribute `_make`"
+    def _make(cls, iterable):
+        return cls(*iterable)
+```
+
+Classes that inherit from a `NamedTuple` class (but don't directly inherit from `NamedTuple`) are
+not subject to these restrictions:
+
+```py
+from typing import NamedTuple
+
+class Base(NamedTuple):
+    x: int
+
+class Child(Base):
+    # This is fine - Child is not directly a NamedTuple
+    _asdict = 42
+```

crates/ty_python_semantic/resources/mdtest/override.md

@@ -283,8 +283,7 @@ class MyNamedTuple(NamedTuple):
     x: int
 
     @override
-    # TODO: this raises an exception at runtime (which we should emit a diagnostic for).
-    # It shouldn't be an `invalid-explicit-override` diagnostic, however.
+    # error: [invalid-named-tuple] "Cannot overwrite NamedTuple attribute `_asdict`"
     def _asdict(self, /) -> dict[str, Any]: ...
 
 class MyNamedTupleParent(NamedTuple):

crates/ty_python_semantic/resources/mdtest/snapshots/classes.md_-_Generic_classes___Leg…_-_Diagnostics_for_bad_…_(2ceba7b720e21b8b).snap

@@ -0,0 +1,78 @@
+---
+source: crates/ty_test/src/lib.rs
+expression: snapshot
+---
+---
+mdtest name: classes.md - Generic classes: Legacy syntax - Diagnostics for bad specializations
+mdtest path: crates/ty_python_semantic/resources/mdtest/generics/legacy/classes.md
+---
+
+# Python source files
+
+## library.py
+
+```
+ 1 | from typing import TypeVar, Generic
+ 2 | 
+ 3 | T = TypeVar("T", bound=str)
+ 4 | U = TypeVar("U", int, bytes)
+ 5 | 
+ 6 | class Bounded(Generic[T]):
+ 7 |     x: T
+ 8 | 
+ 9 | class Constrained(Generic[U]):
+10 |     x: U
+```
+
+## main.py
+
+```
+1 | from library import Bounded, Constrained
+2 | 
+3 | x: Bounded[int]  # error: [invalid-type-arguments]
+4 | y: Constrained[str]  # error: [invalid-type-arguments]
+```
+
+# Diagnostics
+
+```
+error[invalid-type-arguments]: Type `int` is not assignable to upper bound `str` of type variable `T@Bounded`
+ --> src/main.py:3:12
+  |
+1 | from library import Bounded, Constrained
+2 |
+3 | x: Bounded[int]  # error: [invalid-type-arguments]
+  |            ^^^
+4 | y: Constrained[str]  # error: [invalid-type-arguments]
+  |
+ ::: src/library.py:3:1
+  |
+1 | from typing import TypeVar, Generic
+2 |
+3 | T = TypeVar("T", bound=str)
+  | - Type variable defined here
+4 | U = TypeVar("U", int, bytes)
+  |
+info: rule `invalid-type-arguments` is enabled by default
+
+```
+
+```
+error[invalid-type-arguments]: Type `str` does not satisfy constraints `int`, `bytes` of type variable `U@Constrained`
+ --> src/main.py:4:16
+  |
+3 | x: Bounded[int]  # error: [invalid-type-arguments]
+4 | y: Constrained[str]  # error: [invalid-type-arguments]
+  |                ^^^
+  |
+ ::: src/library.py:4:1
+  |
+3 | T = TypeVar("T", bound=str)
+4 | U = TypeVar("U", int, bytes)
+  | - Type variable defined here
+5 |
+6 | class Bounded(Generic[T]):
+  |
+info: rule `invalid-type-arguments` is enabled by default
+
+```

crates/ty_python_semantic/resources/mdtest/snapshots/classes.md_-_Generic_classes___PEP…_-_Diagnostics_for_bad_…_(cf706b07cf0ec31f).snap

@@ -0,0 +1,71 @@
+---
+source: crates/ty_test/src/lib.rs
+expression: snapshot
+---
+---
+mdtest name: classes.md - Generic classes: PEP 695 syntax - Diagnostics for bad specializations
+mdtest path: crates/ty_python_semantic/resources/mdtest/generics/pep695/classes.md
+---
+
+# Python source files
+
+## library.py
+
+```
+1 | class Bounded[T: str]:
+2 |     x: T
+3 | 
+4 | class Constrained[U: (int, bytes)]:
+5 |     x: U
+```
+
+## main.py
+
+```
+1 | from library import Bounded, Constrained
+2 | 
+3 | x: Bounded[int]  # error: [invalid-type-arguments]
+4 | y: Constrained[str]  # error: [invalid-type-arguments]
+```
+
+# Diagnostics
+
+```
+error[invalid-type-arguments]: Type `int` is not assignable to upper bound `str` of type variable `T@Bounded`
+ --> src/main.py:3:12
+  |
+1 | from library import Bounded, Constrained
+2 |
+3 | x: Bounded[int]  # error: [invalid-type-arguments]
+  |            ^^^
+4 | y: Constrained[str]  # error: [invalid-type-arguments]
+  |
+ ::: src/library.py:1:15
+  |
+1 | class Bounded[T: str]:
+  |               - Type variable defined here
+2 |     x: T
+  |
+info: rule `invalid-type-arguments` is enabled by default
+
+```
+
+```
+error[invalid-type-arguments]: Type `str` does not satisfy constraints `int`, `bytes` of type variable `U@Constrained`
+ --> src/main.py:4:16
+  |
+3 | x: Bounded[int]  # error: [invalid-type-arguments]
+4 | y: Constrained[str]  # error: [invalid-type-arguments]
+  |                ^^^
+  |
+ ::: src/library.py:4:19
+  |
+2 |     x: T
+3 |
+4 | class Constrained[U: (int, bytes)]:
+  |                   - Type variable defined here
+5 |     x: U
+  |
+info: rule `invalid-type-arguments` is enabled by default
+
+```

crates/ty_python_semantic/resources/mdtest/snapshots/final.md_-_Tests_for_the_`@typi…_-_A_possibly-undefined…_(fc7b496fd1986deb).snap

@@ -49,26 +49,29 @@ mdtest path: crates/ty_python_semantic/resources/mdtest/final.md
 35 |     def method1(self) -> None: ...  # error: [override-of-final-method]
 36 |     def method2(self) -> None: ...  # error: [override-of-final-method]
 37 |     def method3(self) -> None: ...  # error: [override-of-final-method]
-38 |     def method4(self) -> None: ...  # error: [override-of-final-method]
-39 | 
-40 | # Possible overrides of possibly `@final` methods...
-41 | class C(A):
-42 |     if coinflip():
-43 |         # TODO: the autofix here introduces invalid syntax because there are now no
-44 |         # statements inside the `if:` branch
-45 |         # (but it might still be a useful autofix in an IDE context?)
-46 |         def method1(self) -> None: ...  # error: [override-of-final-method]
-47 |     else:
-48 |         pass
-49 | 
-50 |     if coinflip():
-51 |         def method2(self) -> None: ...  # TODO: should emit [override-of-final-method]
-52 |     else:
-53 |         def method2(self) -> None: ...  # TODO: should emit [override-of-final-method]
-54 | 
-55 |     if coinflip():
-56 |         def method3(self) -> None: ...  # error: [override-of-final-method]
-57 |         def method4(self) -> None: ...  # error: [override-of-final-method]
+38 | 
+39 |     # check that autofixes don't introduce invalid syntax
+40 |     # if there are multiple statements on one line
+41 |     #
+42 |     # TODO: we should emit a Liskov violation here too
+43 |     # error: [override-of-final-method]
+44 |     method4 = 42; unrelated = 56  # fmt: skip
+45 | 
+46 | # Possible overrides of possibly `@final` methods...
+47 | class C(A):
+48 |     if coinflip():
+49 |         def method1(self) -> None: ...  # error: [override-of-final-method]
+50 |     else:
+51 |         pass
+52 | 
+53 |     if coinflip():
+54 |         def method2(self) -> None: ...  # TODO: should emit [override-of-final-method]
+55 |     else:
+56 |         def method2(self) -> None: ...  # TODO: should emit [override-of-final-method]
+57 | 
+58 |     if coinflip():
+59 |         def method3(self) -> None: ...  # error: [override-of-final-method]
+60 |         def method4(self) -> None: ...  # error: [override-of-final-method]
 ```
 
 # Diagnostics
@@ -104,7 +107,7 @@ info: rule `override-of-final-method` is enabled by default
 35 +       # error: [override-of-final-method]
 36 |     def method2(self) -> None: ...  # error: [override-of-final-method]
 37 |     def method3(self) -> None: ...  # error: [override-of-final-method]
-38 |     def method4(self) -> None: ...  # error: [override-of-final-method]
+38 | 
 note: This is an unsafe fix and may change runtime behavior
 
 ```
@@ -118,7 +121,6 @@ error[override-of-final-method]: Cannot override `A.method2`
 36 |     def method2(self) -> None: ...  # error: [override-of-final-method]
    |         ^^^^^^^ Overrides a definition from superclass `A`
 37 |     def method3(self) -> None: ...  # error: [override-of-final-method]
-38 |     def method4(self) -> None: ...  # error: [override-of-final-method]
    |
 info: `A.method2` is decorated with `@final`, forbidding overrides
   --> src/mdtest_snippet.py:16:9
@@ -140,8 +142,8 @@ info: rule `override-of-final-method` is enabled by default
    -     def method2(self) -> None: ...  # error: [override-of-final-method]
 36 +       # error: [override-of-final-method]
 37 |     def method3(self) -> None: ...  # error: [override-of-final-method]
-38 |     def method4(self) -> None: ...  # error: [override-of-final-method]
-39 | 
+38 | 
+39 |     # check that autofixes don't introduce invalid syntax
 note: This is an unsafe fix and may change runtime behavior
 
 ```
@@ -154,7 +156,8 @@ error[override-of-final-method]: Cannot override `A.method3`
 36 |     def method2(self) -> None: ...  # error: [override-of-final-method]
 37 |     def method3(self) -> None: ...  # error: [override-of-final-method]
    |         ^^^^^^^ Overrides a definition from superclass `A`
-38 |     def method4(self) -> None: ...  # error: [override-of-final-method]
+38 |
+39 |     # check that autofixes don't introduce invalid syntax
    |
 info: `A.method3` is decorated with `@final`, forbidding overrides
   --> src/mdtest_snippet.py:20:9
@@ -174,23 +177,23 @@ info: rule `override-of-final-method` is enabled by default
 36 |     def method2(self) -> None: ...  # error: [override-of-final-method]
    -     def method3(self) -> None: ...  # error: [override-of-final-method]
 37 +       # error: [override-of-final-method]
-38 |     def method4(self) -> None: ...  # error: [override-of-final-method]
-39 | 
-40 | # Possible overrides of possibly `@final` methods...
+38 | 
+39 |     # check that autofixes don't introduce invalid syntax
+40 |     # if there are multiple statements on one line
 note: This is an unsafe fix and may change runtime behavior
 
 ```
 
 ```
 error[override-of-final-method]: Cannot override `A.method4`
-  --> src/mdtest_snippet.py:38:9
+  --> src/mdtest_snippet.py:44:5
    |
-36 |     def method2(self) -> None: ...  # error: [override-of-final-method]
-37 |     def method3(self) -> None: ...  # error: [override-of-final-method]
-38 |     def method4(self) -> None: ...  # error: [override-of-final-method]
-   |         ^^^^^^^ Overrides a definition from superclass `A`
-39 |
-40 | # Possible overrides of possibly `@final` methods...
+42 |     # TODO: we should emit a Liskov violation here too
+43 |     # error: [override-of-final-method]
+44 |     method4 = 42; unrelated = 56  # fmt: skip
+   |     ^^^^^^^ Overrides a definition from superclass `A`
+45 |
+46 | # Possible overrides of possibly `@final` methods...
    |
 info: `A.method4` is decorated with `@final`, forbidding overrides
   --> src/mdtest_snippet.py:29:9
@@ -206,28 +209,19 @@ info: `A.method4` is decorated with `@final`, forbidding overrides
    |
 help: Remove the override of `method4`
 info: rule `override-of-final-method` is enabled by default
-35 |     def method1(self) -> None: ...  # error: [override-of-final-method]
-36 |     def method2(self) -> None: ...  # error: [override-of-final-method]
-37 |     def method3(self) -> None: ...  # error: [override-of-final-method]
-   -     def method4(self) -> None: ...  # error: [override-of-final-method]
-38 +       # error: [override-of-final-method]
-39 | 
-40 | # Possible overrides of possibly `@final` methods...
-41 | class C(A):
-note: This is an unsafe fix and may change runtime behavior
 
 ```
 
 ```
 error[override-of-final-method]: Cannot override `A.method1`
-  --> src/mdtest_snippet.py:46:13
+  --> src/mdtest_snippet.py:49:13
    |
-44 |         # statements inside the `if:` branch
-45 |         # (but it might still be a useful autofix in an IDE context?)
-46 |         def method1(self) -> None: ...  # error: [override-of-final-method]
+47 | class C(A):
+48 |     if coinflip():
+49 |         def method1(self) -> None: ...  # error: [override-of-final-method]
    |             ^^^^^^^ Overrides a definition from superclass `A`
-47 |     else:
-48 |         pass
+50 |     else:
+51 |         pass
    |
 info: `A.method1` is decorated with `@final`, forbidding overrides
   --> src/mdtest_snippet.py:8:9
@@ -243,26 +237,17 @@ info: `A.method1` is decorated with `@final`, forbidding overrides
    |
 help: Remove the override of `method1`
 info: rule `override-of-final-method` is enabled by default
-43 |         # TODO: the autofix here introduces invalid syntax because there are now no
-44 |         # statements inside the `if:` branch
-45 |         # (but it might still be a useful autofix in an IDE context?)
-   -         def method1(self) -> None: ...  # error: [override-of-final-method]
-46 +           # error: [override-of-final-method]
-47 |     else:
-48 |         pass
-49 | 
-note: This is an unsafe fix and may change runtime behavior
 
 ```
 
 ```
 error[override-of-final-method]: Cannot override `A.method3`
-  --> src/mdtest_snippet.py:56:13
+  --> src/mdtest_snippet.py:59:13
    |
-55 |     if coinflip():
-56 |         def method3(self) -> None: ...  # error: [override-of-final-method]
+58 |     if coinflip():
+59 |         def method3(self) -> None: ...  # error: [override-of-final-method]
    |             ^^^^^^^ Overrides a definition from superclass `A`
-57 |         def method4(self) -> None: ...  # error: [override-of-final-method]
+60 |         def method4(self) -> None: ...  # error: [override-of-final-method]
    |
 info: `A.method3` is decorated with `@final`, forbidding overrides
   --> src/mdtest_snippet.py:20:9
@@ -277,23 +262,16 @@ info: `A.method3` is decorated with `@final`, forbidding overrides
    |
 help: Remove the override of `method3`
 info: rule `override-of-final-method` is enabled by default
-53 |         def method2(self) -> None: ...  # TODO: should emit [override-of-final-method]
-54 | 
-55 |     if coinflip():
-   -         def method3(self) -> None: ...  # error: [override-of-final-method]
-56 +           # error: [override-of-final-method]
-57 |         def method4(self) -> None: ...  # error: [override-of-final-method]
-note: This is an unsafe fix and may change runtime behavior
 
 ```
 
 ```
 error[override-of-final-method]: Cannot override `A.method4`
-  --> src/mdtest_snippet.py:57:13
+  --> src/mdtest_snippet.py:60:13
    |
-55 |     if coinflip():
-56 |         def method3(self) -> None: ...  # error: [override-of-final-method]
-57 |         def method4(self) -> None: ...  # error: [override-of-final-method]
+58 |     if coinflip():
+59 |         def method3(self) -> None: ...  # error: [override-of-final-method]
+60 |         def method4(self) -> None: ...  # error: [override-of-final-method]
    |             ^^^^^^^ Overrides a definition from superclass `A`
    |
 info: `A.method4` is decorated with `@final`, forbidding overrides
@@ -310,11 +288,5 @@ info: `A.method4` is decorated with `@final`, forbidding overrides
    |
 help: Remove the override of `method4`
 info: rule `override-of-final-method` is enabled by default
-54 | 
-55 |     if coinflip():
-56 |         def method3(self) -> None: ...  # error: [override-of-final-method]
-   -         def method4(self) -> None: ...  # error: [override-of-final-method]
-57 +           # error: [override-of-final-method]
-note: This is an unsafe fix and may change runtime behavior
 
 ```

crates/ty_python_semantic/resources/mdtest/snapshots/final.md_-_Tests_for_the_`@typi…_-_Cannot_override_a_me…_(338615109711a91b).snap

@@ -28,93 +28,93 @@ mdtest path: crates/ty_python_semantic/resources/mdtest/final.md
  14 |     @final
  15 |     def my_property2(self) -> int: ...
  16 | 
- 17 |     @final
- 18 |     @classmethod
- 19 |     def class_method1(cls) -> int: ...
+ 17 |     @property
+ 18 |     @final
+ 19 |     def my_property3(self) -> int: ...
  20 | 
- 21 |     @classmethod
- 22 |     @final
- 23 |     def class_method2(cls) -> int: ...
+ 21 |     @final
+ 22 |     @classmethod
+ 23 |     def class_method1(cls) -> int: ...
  24 | 
- 25 |     @final
- 26 |     @staticmethod
- 27 |     def static_method1() -> int: ...
+ 25 |     @classmethod
+ 26 |     @final
+ 27 |     def class_method2(cls) -> int: ...
  28 | 
- 29 |     @staticmethod
- 30 |     @final
- 31 |     def static_method2() -> int: ...
+ 29 |     @final
+ 30 |     @staticmethod
+ 31 |     def static_method1() -> int: ...
  32 | 
- 33 |     @lossy_decorator
+ 33 |     @staticmethod
  34 |     @final
- 35 |     def decorated_1(self): ...
+ 35 |     def static_method2() -> int: ...
  36 | 
- 37 |     @final
- 38 |     @lossy_decorator
- 39 |     def decorated_2(self): ...
+ 37 |     @lossy_decorator
+ 38 |     @final
+ 39 |     def decorated_1(self): ...
  40 | 
- 41 | class Child(Parent):
- 42 |     # explicitly test the concise diagnostic message,
- 43 |     # which is different to the verbose diagnostic summary message:
- 44 |     #
- 45 |     # error: [override-of-final-method] "Cannot override final member `foo` from superclass `Parent`"
- 46 |     def foo(self): ...
- 47 |     @property
- 48 |     def my_property1(self) -> int: ...  # error: [override-of-final-method]
- 49 | 
- 50 |     @property
- 51 |     def my_property2(self) -> int: ...  # error: [override-of-final-method]
- 52 | 
- 53 |     @classmethod
- 54 |     def class_method1(cls) -> int: ...  # error: [override-of-final-method]
- 55 | 
- 56 |     @staticmethod
- 57 |     def static_method1() -> int: ...  # error: [override-of-final-method]
+ 41 |     @final
+ 42 |     @lossy_decorator
+ 43 |     def decorated_2(self): ...
+ 44 | 
+ 45 | class Child(Parent):
+ 46 |     # explicitly test the concise diagnostic message,
+ 47 |     # which is different to the verbose diagnostic summary message:
+ 48 |     #
+ 49 |     # error: [override-of-final-method] "Cannot override final member `foo` from superclass `Parent`"
+ 50 |     def foo(self): ...
+ 51 |     @property
+ 52 |     def my_property1(self) -> int: ...  # error: [override-of-final-method]
+ 53 | 
+ 54 |     @property
+ 55 |     def my_property2(self) -> int: ...  # error: [override-of-final-method]
+ 56 |     @my_property2.setter
+ 57 |     def my_property2(self, x: int) -> None: ...
  58 | 
- 59 |     @classmethod
- 60 |     def class_method2(cls) -> int: ...  # error: [override-of-final-method]
- 61 | 
- 62 |     @staticmethod
- 63 |     def static_method2() -> int: ...  # error: [override-of-final-method]
- 64 | 
- 65 |     def decorated_1(self): ...  # TODO: should emit [override-of-final-method]
+ 59 |     @property
+ 60 |     def my_property3(self) -> int: ...  # error: [override-of-final-method]
+ 61 |     @my_property3.deleter
+ 62 |     def my_proeprty3(self) -> None: ...
+ 63 | 
+ 64 |     @classmethod
+ 65 |     def class_method1(cls) -> int: ...  # error: [override-of-final-method]
  66 | 
- 67 |     @lossy_decorator
- 68 |     def decorated_2(self): ...  # TODO: should emit [override-of-final-method]
+ 67 |     @staticmethod
+ 68 |     def static_method1() -> int: ...  # error: [override-of-final-method]
  69 | 
- 70 | class OtherChild(Parent): ...
- 71 | 
- 72 | class Grandchild(OtherChild):
+ 70 |     @classmethod
+ 71 |     def class_method2(cls) -> int: ...  # error: [override-of-final-method]
+ 72 | 
  73 |     @staticmethod
- 74 |     # TODO: we should emit a Liskov violation here too
- 75 |     # error: [override-of-final-method]
- 76 |     def foo(): ...
- 77 |     @property
- 78 |     # TODO: we should emit a Liskov violation here too
- 79 |     # error: [override-of-final-method]
- 80 |     def my_property1(self) -> str: ...
- 81 |     # TODO: we should emit a Liskov violation here too
- 82 |     # error: [override-of-final-method]
- 83 |     class_method1 = None
- 84 | 
- 85 | # Diagnostic edge case: `final` is very far away from the method definition in the source code:
- 86 | 
- 87 | T = TypeVar("T")
- 88 | 
- 89 | def identity(x: T) -> T: ...
- 90 | 
- 91 | class Foo:
- 92 |     @final
- 93 |     @identity
- 94 |     @identity
- 95 |     @identity
- 96 |     @identity
- 97 |     @identity
- 98 |     @identity
- 99 |     @identity
-100 |     @identity
-101 |     @identity
-102 |     @identity
-103 |     @identity
+ 74 |     def static_method2() -> int: ...  # error: [override-of-final-method]
+ 75 | 
+ 76 |     def decorated_1(self): ...  # TODO: should emit [override-of-final-method]
+ 77 | 
+ 78 |     @lossy_decorator
+ 79 |     def decorated_2(self): ...  # TODO: should emit [override-of-final-method]
+ 80 | 
+ 81 | class OtherChild(Parent): ...
+ 82 | 
+ 83 | class Grandchild(OtherChild):
+ 84 |     @staticmethod
+ 85 |     # TODO: we should emit a Liskov violation here too
+ 86 |     # error: [override-of-final-method]
+ 87 |     def foo(): ...
+ 88 |     @property
+ 89 |     # TODO: we should emit a Liskov violation here too
+ 90 |     # error: [override-of-final-method]
+ 91 |     def my_property1(self) -> str: ...
+ 92 |     # TODO: we should emit a Liskov violation here too
+ 93 |     # error: [override-of-final-method]
+ 94 |     class_method1 = None
+ 95 | 
+ 96 | # Diagnostic edge case: `final` is very far away from the method definition in the source code:
+ 97 | 
+ 98 | T = TypeVar("T")
+ 99 | 
+100 | def identity(x: T) -> T: ...
+101 | 
+102 | class Foo:
+103 |     @final
 104 |     @identity
 105 |     @identity
 106 |     @identity
@@ -122,24 +122,35 @@ mdtest path: crates/ty_python_semantic/resources/mdtest/final.md
 108 |     @identity
 109 |     @identity
 110 |     @identity
-111 |     def bar(self): ...
-112 | 
-113 | class Baz(Foo):
-114 |     def bar(self): ...  # error: [override-of-final-method]
+111 |     @identity
+112 |     @identity
+113 |     @identity
+114 |     @identity
+115 |     @identity
+116 |     @identity
+117 |     @identity
+118 |     @identity
+119 |     @identity
+120 |     @identity
+121 |     @identity
+122 |     def bar(self): ...
+123 | 
+124 | class Baz(Foo):
+125 |     def bar(self): ...  # error: [override-of-final-method]
 ```
 
 # Diagnostics
 
 ```
 error[override-of-final-method]: Cannot override `Parent.foo`
-  --> src/mdtest_snippet.pyi:46:9
+  --> src/mdtest_snippet.pyi:50:9
    |
-44 |     #
-45 |     # error: [override-of-final-method] "Cannot override final member `foo` from superclass `Parent`"
-46 |     def foo(self): ...
+48 |     #
+49 |     # error: [override-of-final-method] "Cannot override final member `foo` from superclass `Parent`"
+50 |     def foo(self): ...
    |         ^^^ Overrides a definition from superclass `Parent`
-47 |     @property
-48 |     def my_property1(self) -> int: ...  # error: [override-of-final-method]
+51 |     @property
+52 |     def my_property1(self) -> int: ...  # error: [override-of-final-method]
    |
 info: `Parent.foo` is decorated with `@final`, forbidding overrides
  --> src/mdtest_snippet.pyi:6:5
@@ -154,28 +165,28 @@ info: `Parent.foo` is decorated with `@final`, forbidding overrides
   |
 help: Remove the override of `foo`
 info: rule `override-of-final-method` is enabled by default
-43 |     # which is different to the verbose diagnostic summary message:
-44 |     #
-45 |     # error: [override-of-final-method] "Cannot override final member `foo` from superclass `Parent`"
+47 |     # which is different to the verbose diagnostic summary message:
+48 |     #
+49 |     # error: [override-of-final-method] "Cannot override final member `foo` from superclass `Parent`"
    -     def foo(self): ...
-46 +     
-47 |     @property
-48 |     def my_property1(self) -> int: ...  # error: [override-of-final-method]
-49 | 
+50 +     
+51 |     @property
+52 |     def my_property1(self) -> int: ...  # error: [override-of-final-method]
+53 | 
 note: This is an unsafe fix and may change runtime behavior
 
 ```
 
 ```
 error[override-of-final-method]: Cannot override `Parent.my_property1`
-  --> src/mdtest_snippet.pyi:48:9
+  --> src/mdtest_snippet.pyi:52:9
    |
-46 |     def foo(self): ...
-47 |     @property
-48 |     def my_property1(self) -> int: ...  # error: [override-of-final-method]
+50 |     def foo(self): ...
+51 |     @property
+52 |     def my_property1(self) -> int: ...  # error: [override-of-final-method]
    |         ^^^^^^^^^^^^ Overrides a definition from superclass `Parent`
-49 |
-50 |     @property
+53 |
+54 |     @property
    |
 info: `Parent.my_property1` is decorated with `@final`, forbidding overrides
   --> src/mdtest_snippet.pyi:9:5
@@ -192,28 +203,18 @@ info: `Parent.my_property1` is decorated with `@final`, forbidding overrides
    |
 help: Remove the override of `my_property1`
 info: rule `override-of-final-method` is enabled by default
-44 |     #
-45 |     # error: [override-of-final-method] "Cannot override final member `foo` from superclass `Parent`"
-46 |     def foo(self): ...
-   -     @property
-   -     def my_property1(self) -> int: ...  # error: [override-of-final-method]
-47 +       # error: [override-of-final-method]
-48 | 
-49 |     @property
-50 |     def my_property2(self) -> int: ...  # error: [override-of-final-method]
-note: This is an unsafe fix and may change runtime behavior
 
 ```
 
 ```
 error[override-of-final-method]: Cannot override `Parent.my_property2`
-  --> src/mdtest_snippet.pyi:51:9
+  --> src/mdtest_snippet.pyi:55:9
    |
-50 |     @property
-51 |     def my_property2(self) -> int: ...  # error: [override-of-final-method]
+54 |     @property
+55 |     def my_property2(self) -> int: ...  # error: [override-of-final-method]
    |         ^^^^^^^^^^^^ Overrides a definition from superclass `Parent`
-52 |
-53 |     @classmethod
+56 |     @my_property2.setter
+57 |     def my_property2(self, x: int) -> None: ...
    |
 info: `Parent.my_property2` is decorated with `@final`, forbidding overrides
   --> src/mdtest_snippet.pyi:14:5
@@ -224,181 +225,197 @@ info: `Parent.my_property2` is decorated with `@final`, forbidding overrides
 15 |     def my_property2(self) -> int: ...
    |         ------------ `Parent.my_property2` defined here
 16 |
-17 |     @final
+17 |     @property
    |
-help: Remove the override of `my_property2`
+help: Remove the getter and setter for `my_property2`
+info: rule `override-of-final-method` is enabled by default
+
+```
+
+```
+error[override-of-final-method]: Cannot override `Parent.my_property3`
+  --> src/mdtest_snippet.pyi:60:9
+   |
+59 |     @property
+60 |     def my_property3(self) -> int: ...  # error: [override-of-final-method]
+   |         ^^^^^^^^^^^^ Overrides a definition from superclass `Parent`
+61 |     @my_property3.deleter
+62 |     def my_proeprty3(self) -> None: ...
+   |
+info: `Parent.my_property3` is decorated with `@final`, forbidding overrides
+  --> src/mdtest_snippet.pyi:18:5
+   |
+17 |     @property
+18 |     @final
+   |     ------
+19 |     def my_property3(self) -> int: ...
+   |         ------------ `Parent.my_property3` defined here
+20 |
+21 |     @final
+   |
+help: Remove the override of `my_property3`
 info: rule `override-of-final-method` is enabled by default
-47 |     @property
-48 |     def my_property1(self) -> int: ...  # error: [override-of-final-method]
-49 | 
-   -     @property
-   -     def my_property2(self) -> int: ...  # error: [override-of-final-method]
-50 +       # error: [override-of-final-method]
-51 | 
-52 |     @classmethod
-53 |     def class_method1(cls) -> int: ...  # error: [override-of-final-method]
-note: This is an unsafe fix and may change runtime behavior
 
 ```
 
 ```
 error[override-of-final-method]: Cannot override `Parent.class_method1`
-  --> src/mdtest_snippet.pyi:54:9
+  --> src/mdtest_snippet.pyi:65:9
    |
-53 |     @classmethod
-54 |     def class_method1(cls) -> int: ...  # error: [override-of-final-method]
+64 |     @classmethod
+65 |     def class_method1(cls) -> int: ...  # error: [override-of-final-method]
    |         ^^^^^^^^^^^^^ Overrides a definition from superclass `Parent`
-55 |
-56 |     @staticmethod
+66 |
+67 |     @staticmethod
    |
 info: `Parent.class_method1` is decorated with `@final`, forbidding overrides
-  --> src/mdtest_snippet.pyi:17:5
+  --> src/mdtest_snippet.pyi:21:5
    |
-15 |     def my_property2(self) -> int: ...
-16 |
-17 |     @final
-   |     ------
-18 |     @classmethod
-19 |     def class_method1(cls) -> int: ...
-   |         ------------- `Parent.class_method1` defined here
+19 |     def my_property3(self) -> int: ...
 20 |
-21 |     @classmethod
+21 |     @final
+   |     ------
+22 |     @classmethod
+23 |     def class_method1(cls) -> int: ...
+   |         ------------- `Parent.class_method1` defined here
+24 |
+25 |     @classmethod
    |
 help: Remove the override of `class_method1`
 info: rule `override-of-final-method` is enabled by default
-50 |     @property
-51 |     def my_property2(self) -> int: ...  # error: [override-of-final-method]
-52 | 
+61 |     @my_property3.deleter
+62 |     def my_proeprty3(self) -> None: ...
+63 | 
    -     @classmethod
    -     def class_method1(cls) -> int: ...  # error: [override-of-final-method]
-53 +       # error: [override-of-final-method]
-54 | 
-55 |     @staticmethod
-56 |     def static_method1() -> int: ...  # error: [override-of-final-method]
+64 +       # error: [override-of-final-method]
+65 | 
+66 |     @staticmethod
+67 |     def static_method1() -> int: ...  # error: [override-of-final-method]
 note: This is an unsafe fix and may change runtime behavior
 
 ```
 
 ```
 error[override-of-final-method]: Cannot override `Parent.static_method1`
-  --> src/mdtest_snippet.pyi:57:9
+  --> src/mdtest_snippet.pyi:68:9
    |
-56 |     @staticmethod
-57 |     def static_method1() -> int: ...  # error: [override-of-final-method]
+67 |     @staticmethod
+68 |     def static_method1() -> int: ...  # error: [override-of-final-method]
    |         ^^^^^^^^^^^^^^ Overrides a definition from superclass `Parent`
-58 |
-59 |     @classmethod
+69 |
+70 |     @classmethod
    |
 info: `Parent.static_method1` is decorated with `@final`, forbidding overrides
-  --> src/mdtest_snippet.pyi:25:5
+  --> src/mdtest_snippet.pyi:29:5
    |
-23 |     def class_method2(cls) -> int: ...
-24 |
-25 |     @final
-   |     ------
-26 |     @staticmethod
-27 |     def static_method1() -> int: ...
-   |         -------------- `Parent.static_method1` defined here
+27 |     def class_method2(cls) -> int: ...
 28 |
-29 |     @staticmethod
+29 |     @final
+   |     ------
+30 |     @staticmethod
+31 |     def static_method1() -> int: ...
+   |         -------------- `Parent.static_method1` defined here
+32 |
+33 |     @staticmethod
    |
 help: Remove the override of `static_method1`
 info: rule `override-of-final-method` is enabled by default
-53 |     @classmethod
-54 |     def class_method1(cls) -> int: ...  # error: [override-of-final-method]
-55 | 
+64 |     @classmethod
+65 |     def class_method1(cls) -> int: ...  # error: [override-of-final-method]
+66 | 
    -     @staticmethod
    -     def static_method1() -> int: ...  # error: [override-of-final-method]
-56 +       # error: [override-of-final-method]
-57 | 
-58 |     @classmethod
-59 |     def class_method2(cls) -> int: ...  # error: [override-of-final-method]
+67 +       # error: [override-of-final-method]
+68 | 
+69 |     @classmethod
+70 |     def class_method2(cls) -> int: ...  # error: [override-of-final-method]
 note: This is an unsafe fix and may change runtime behavior
 
 ```
 
 ```
 error[override-of-final-method]: Cannot override `Parent.class_method2`
-  --> src/mdtest_snippet.pyi:60:9
+  --> src/mdtest_snippet.pyi:71:9
    |
-59 |     @classmethod
-60 |     def class_method2(cls) -> int: ...  # error: [override-of-final-method]
+70 |     @classmethod
+71 |     def class_method2(cls) -> int: ...  # error: [override-of-final-method]
    |         ^^^^^^^^^^^^^ Overrides a definition from superclass `Parent`
-61 |
-62 |     @staticmethod
+72 |
+73 |     @staticmethod
    |
 info: `Parent.class_method2` is decorated with `@final`, forbidding overrides
-  --> src/mdtest_snippet.pyi:22:5
+  --> src/mdtest_snippet.pyi:26:5
    |
-21 |     @classmethod
-22 |     @final
+25 |     @classmethod
+26 |     @final
    |     ------
-23 |     def class_method2(cls) -> int: ...
+27 |     def class_method2(cls) -> int: ...
    |         ------------- `Parent.class_method2` defined here
-24 |
-25 |     @final
+28 |
+29 |     @final
    |
 help: Remove the override of `class_method2`
 info: rule `override-of-final-method` is enabled by default
-56 |     @staticmethod
-57 |     def static_method1() -> int: ...  # error: [override-of-final-method]
-58 | 
+67 |     @staticmethod
+68 |     def static_method1() -> int: ...  # error: [override-of-final-method]
+69 | 
    -     @classmethod
    -     def class_method2(cls) -> int: ...  # error: [override-of-final-method]
-59 +       # error: [override-of-final-method]
-60 | 
-61 |     @staticmethod
-62 |     def static_method2() -> int: ...  # error: [override-of-final-method]
+70 +       # error: [override-of-final-method]
+71 | 
+72 |     @staticmethod
+73 |     def static_method2() -> int: ...  # error: [override-of-final-method]
 note: This is an unsafe fix and may change runtime behavior
 
 ```
 
 ```
 error[override-of-final-method]: Cannot override `Parent.static_method2`
-  --> src/mdtest_snippet.pyi:63:9
+  --> src/mdtest_snippet.pyi:74:9
    |
-62 |     @staticmethod
-63 |     def static_method2() -> int: ...  # error: [override-of-final-method]
+73 |     @staticmethod
+74 |     def static_method2() -> int: ...  # error: [override-of-final-method]
    |         ^^^^^^^^^^^^^^ Overrides a definition from superclass `Parent`
-64 |
-65 |     def decorated_1(self): ...  # TODO: should emit [override-of-final-method]
+75 |
+76 |     def decorated_1(self): ...  # TODO: should emit [override-of-final-method]
    |
 info: `Parent.static_method2` is decorated with `@final`, forbidding overrides
-  --> src/mdtest_snippet.pyi:30:5
+  --> src/mdtest_snippet.pyi:34:5
    |
-29 |     @staticmethod
-30 |     @final
+33 |     @staticmethod
+34 |     @final
    |     ------
-31 |     def static_method2() -> int: ...
+35 |     def static_method2() -> int: ...
    |         -------------- `Parent.static_method2` defined here
-32 |
-33 |     @lossy_decorator
+36 |
+37 |     @lossy_decorator
    |
 help: Remove the override of `static_method2`
 info: rule `override-of-final-method` is enabled by default
-59 |     @classmethod
-60 |     def class_method2(cls) -> int: ...  # error: [override-of-final-method]
-61 | 
+70 |     @classmethod
+71 |     def class_method2(cls) -> int: ...  # error: [override-of-final-method]
+72 | 
    -     @staticmethod
    -     def static_method2() -> int: ...  # error: [override-of-final-method]
-62 +       # error: [override-of-final-method]
-63 | 
-64 |     def decorated_1(self): ...  # TODO: should emit [override-of-final-method]
-65 | 
+73 +       # error: [override-of-final-method]
+74 | 
+75 |     def decorated_1(self): ...  # TODO: should emit [override-of-final-method]
+76 | 
 note: This is an unsafe fix and may change runtime behavior
 
 ```
 
 ```
 error[override-of-final-method]: Cannot override `Parent.foo`
-  --> src/mdtest_snippet.pyi:76:9
+  --> src/mdtest_snippet.pyi:87:9
    |
-74 |     # TODO: we should emit a Liskov violation here too
-75 |     # error: [override-of-final-method]
-76 |     def foo(): ...
+85 |     # TODO: we should emit a Liskov violation here too
+86 |     # error: [override-of-final-method]
+87 |     def foo(): ...
    |         ^^^ Overrides a definition from superclass `Parent`
-77 |     @property
-78 |     # TODO: we should emit a Liskov violation here too
+88 |     @property
+89 |     # TODO: we should emit a Liskov violation here too
    |
 info: `Parent.foo` is decorated with `@final`, forbidding overrides
  --> src/mdtest_snippet.pyi:6:5
@@ -413,31 +430,31 @@ info: `Parent.foo` is decorated with `@final`, forbidding overrides
   |
 help: Remove the override of `foo`
 info: rule `override-of-final-method` is enabled by default
-70 | class OtherChild(Parent): ...
-71 | 
-72 | class Grandchild(OtherChild):
+81 | class OtherChild(Parent): ...
+82 | 
+83 | class Grandchild(OtherChild):
    -     @staticmethod
    -     # TODO: we should emit a Liskov violation here too
    -     # error: [override-of-final-method]
    -     def foo(): ...
-73 +     
-74 |     @property
-75 |     # TODO: we should emit a Liskov violation here too
-76 |     # error: [override-of-final-method]
+84 +     
+85 |     @property
+86 |     # TODO: we should emit a Liskov violation here too
+87 |     # error: [override-of-final-method]
 note: This is an unsafe fix and may change runtime behavior
 
 ```
 
 ```
 error[override-of-final-method]: Cannot override `Parent.my_property1`
-  --> src/mdtest_snippet.pyi:80:9
+  --> src/mdtest_snippet.pyi:91:9
    |
-78 |     # TODO: we should emit a Liskov violation here too
-79 |     # error: [override-of-final-method]
-80 |     def my_property1(self) -> str: ...
+89 |     # TODO: we should emit a Liskov violation here too
+90 |     # error: [override-of-final-method]
+91 |     def my_property1(self) -> str: ...
    |         ^^^^^^^^^^^^ Overrides a definition from superclass `Parent`
-81 |     # TODO: we should emit a Liskov violation here too
-82 |     # error: [override-of-final-method]
+92 |     # TODO: we should emit a Liskov violation here too
+93 |     # error: [override-of-final-method]
    |
 info: `Parent.my_property1` is decorated with `@final`, forbidding overrides
   --> src/mdtest_snippet.pyi:9:5
@@ -454,92 +471,71 @@ info: `Parent.my_property1` is decorated with `@final`, forbidding overrides
    |
 help: Remove the override of `my_property1`
 info: rule `override-of-final-method` is enabled by default
-74 |     # TODO: we should emit a Liskov violation here too
-75 |     # error: [override-of-final-method]
-76 |     def foo(): ...
-   -     @property
-   -     # TODO: we should emit a Liskov violation here too
-   -     # error: [override-of-final-method]
-   -     def my_property1(self) -> str: ...
-77 +     
-78 |     # TODO: we should emit a Liskov violation here too
-79 |     # error: [override-of-final-method]
-80 |     class_method1 = None
-note: This is an unsafe fix and may change runtime behavior
 
 ```
 
 ```
 error[override-of-final-method]: Cannot override `Parent.class_method1`
-  --> src/mdtest_snippet.pyi:83:5
+  --> src/mdtest_snippet.pyi:94:5
    |
-81 |     # TODO: we should emit a Liskov violation here too
-82 |     # error: [override-of-final-method]
-83 |     class_method1 = None
+92 |     # TODO: we should emit a Liskov violation here too
+93 |     # error: [override-of-final-method]
+94 |     class_method1 = None
    |     ^^^^^^^^^^^^^ Overrides a definition from superclass `Parent`
-84 |
-85 | # Diagnostic edge case: `final` is very far away from the method definition in the source code:
+95 |
+96 | # Diagnostic edge case: `final` is very far away from the method definition in the source code:
    |
 info: `Parent.class_method1` is decorated with `@final`, forbidding overrides
-  --> src/mdtest_snippet.pyi:17:5
+  --> src/mdtest_snippet.pyi:21:5
    |
-15 |     def my_property2(self) -> int: ...
-16 |
-17 |     @final
-   |     ------
-18 |     @classmethod
-19 |     def class_method1(cls) -> int: ...
-   |         ------------- `Parent.class_method1` defined here
+19 |     def my_property3(self) -> int: ...
 20 |
-21 |     @classmethod
+21 |     @final
+   |     ------
+22 |     @classmethod
+23 |     def class_method1(cls) -> int: ...
+   |         ------------- `Parent.class_method1` defined here
+24 |
+25 |     @classmethod
    |
 help: Remove the override of `class_method1`
 info: rule `override-of-final-method` is enabled by default
-80 |     def my_property1(self) -> str: ...
-81 |     # TODO: we should emit a Liskov violation here too
-82 |     # error: [override-of-final-method]
-   -     class_method1 = None
-83 +     
-84 | 
-85 | # Diagnostic edge case: `final` is very far away from the method definition in the source code:
-86 | 
-note: This is an unsafe fix and may change runtime behavior
 
 ```
 
 ```
 error[override-of-final-method]: Cannot override `Foo.bar`
-   --> src/mdtest_snippet.pyi:114:9
+   --> src/mdtest_snippet.pyi:125:9
     |
-113 | class Baz(Foo):
-114 |     def bar(self): ...  # error: [override-of-final-method]
+124 | class Baz(Foo):
+125 |     def bar(self): ...  # error: [override-of-final-method]
     |         ^^^ Overrides a definition from superclass `Foo`
     |
 info: `Foo.bar` is decorated with `@final`, forbidding overrides
-   --> src/mdtest_snippet.pyi:92:5
+   --> src/mdtest_snippet.pyi:103:5
     |
- 91 | class Foo:
- 92 |     @final
+102 | class Foo:
+103 |     @final
     |     ------
- 93 |     @identity
- 94 |     @identity
+104 |     @identity
+105 |     @identity
     |
-   ::: src/mdtest_snippet.pyi:111:9
+   ::: src/mdtest_snippet.pyi:122:9
     |
-109 |     @identity
-110 |     @identity
-111 |     def bar(self): ...
+120 |     @identity
+121 |     @identity
+122 |     def bar(self): ...
     |         --- `Foo.bar` defined here
-112 |
-113 | class Baz(Foo):
+123 |
+124 | class Baz(Foo):
     |
 help: Remove the override of `bar`
 info: rule `override-of-final-method` is enabled by default
-111 |     def bar(self): ...
-112 | 
-113 | class Baz(Foo):
+122 |     def bar(self): ...
+123 | 
+124 | class Baz(Foo):
     -     def bar(self): ...  # error: [override-of-final-method]
-114 +       # error: [override-of-final-method]
+125 +     pass  # error: [override-of-final-method]
 note: This is an unsafe fix and may change runtime behavior
 
 ```

crates/ty_python_semantic/resources/mdtest/snapshots/final.md_-_Tests_for_the_`@typi…_-_Diagnostic_edge_case…_(2389d52c5ecfa2bd).snap

@@ -53,7 +53,7 @@ info: rule `override-of-final-method` is enabled by default
 2 | 
 3 | class Foo(module1.Foo):
   -     def f(self): ...  # error: [override-of-final-method]
-4 +       # error: [override-of-final-method]
+4 +     pass  # error: [override-of-final-method]
 note: This is an unsafe fix and may change runtime behavior
 
 ```

crates/ty_python_semantic/resources/mdtest/snapshots/final.md_-_Tests_for_the_`@typi…_-_Only_the_first_`@fin…_(9863b583f4c651c5).snap

@@ -59,7 +59,7 @@ info: rule `override-of-final-method` is enabled by default
 7  | class B(A):
    -     @final
    -     def f(self): ...  # error: [override-of-final-method]
-8  +       # error: [override-of-final-method]
+8  +     pass  # error: [override-of-final-method]
 9  | 
 10 | class C(B):
 11 |     @final
@@ -95,7 +95,7 @@ info: rule `override-of-final-method` is enabled by default
    -     @final
    -     # we only emit one error here, not two
    -     def f(self): ...  # error: [override-of-final-method]
-12 +       # error: [override-of-final-method]
+12 +     pass  # error: [override-of-final-method]
 note: This is an unsafe fix and may change runtime behavior
 
 ```

crates/ty_python_semantic/resources/mdtest/snapshots/final.md_-_Tests_for_the_`@typi…_-_Overloaded_methods_d…_(861757f48340ed92).snap

@@ -58,7 +58,7 @@ mdtest path: crates/ty_python_semantic/resources/mdtest/final.md
 44 |     def bar(self, x: str) -> str: ...
 45 |     @overload
 46 |     def bar(self, x: int) -> int: ...  # error: [override-of-final-method]
-47 |     
+47 | 
 48 |     @overload
 49 |     def baz(self, x: str) -> str: ...
 50 |     @overload
@@ -265,7 +265,7 @@ error[override-of-final-method]: Cannot override `Bad.bar`
 45 |     @overload
 46 |     def bar(self, x: int) -> int: ...  # error: [override-of-final-method]
    |         ^^^ Overrides a definition from superclass `Bad`
-47 |     
+47 |
 48 |     @overload
    |
 info: `Bad.bar` is decorated with `@final`, forbidding overrides
@@ -287,12 +287,11 @@ info: rule `override-of-final-method` is enabled by default
    -     def bar(self, x: str) -> str: ...
    -     @overload
    -     def bar(self, x: int) -> int: ...  # error: [override-of-final-method]
-43 |     
+43 +     
 44 +       # error: [override-of-final-method]
-45 +     
+45 | 
 46 |     @overload
 47 |     def baz(self, x: str) -> str: ...
-48 |     @overload
 note: This is an unsafe fix and may change runtime behavior
 
 ```
@@ -319,7 +318,7 @@ help: Remove all overloads for `baz`
 info: rule `override-of-final-method` is enabled by default
 45 |     @overload
 46 |     def bar(self, x: int) -> int: ...  # error: [override-of-final-method]
-47 |     
+47 | 
    -     @overload
    -     def baz(self, x: str) -> str: ...
    -     @overload
@@ -360,12 +359,12 @@ info: rule `override-of-final-method` is enabled by default
    -     def f(self, x: str) -> str: ...
    -     @overload
    -     def f(self, x: int) -> int: ...
-13 +     
-14 +     
+13 +     pass
+14 +     pass
 15 |     # error: [override-of-final-method]
    -     def f(self, x: int | str) -> int | str:
    -         return x
-16 +     
+16 +     pass
 17 | 
 18 | class Bad:
 19 |     @overload
@@ -459,15 +458,6 @@ info: `Bad.f` is decorated with `@final`, forbidding overrides
    |
 help: Remove the override of `f`
 info: rule `override-of-final-method` is enabled by default
-57 | 
-58 | class ChildOfBad(Bad):
-59 |     # TODO: these should all cause us to emit Liskov violations as well
-   -     f = None  # error: [override-of-final-method]
-60 +       # error: [override-of-final-method]
-61 |     g = None  # error: [override-of-final-method]
-62 |     h = None  # error: [override-of-final-method]
-63 |     i = None  # error: [override-of-final-method]
-note: This is an unsafe fix and may change runtime behavior
 
 ```
 
@@ -493,14 +483,6 @@ info: `Bad.g` is decorated with `@final`, forbidding overrides
    |
 help: Remove the override of `g`
 info: rule `override-of-final-method` is enabled by default
-58 | class ChildOfBad(Bad):
-59 |     # TODO: these should all cause us to emit Liskov violations as well
-60 |     f = None  # error: [override-of-final-method]
-   -     g = None  # error: [override-of-final-method]
-61 +       # error: [override-of-final-method]
-62 |     h = None  # error: [override-of-final-method]
-63 |     i = None  # error: [override-of-final-method]
-note: This is an unsafe fix and may change runtime behavior
 
 ```
 
@@ -525,13 +507,6 @@ info: `Bad.h` is decorated with `@final`, forbidding overrides
    |
 help: Remove the override of `h`
 info: rule `override-of-final-method` is enabled by default
-59 |     # TODO: these should all cause us to emit Liskov violations as well
-60 |     f = None  # error: [override-of-final-method]
-61 |     g = None  # error: [override-of-final-method]
-   -     h = None  # error: [override-of-final-method]
-62 +       # error: [override-of-final-method]
-63 |     i = None  # error: [override-of-final-method]
-note: This is an unsafe fix and may change runtime behavior
 
 ```
 
@@ -555,11 +530,5 @@ info: `Bad.i` is decorated with `@final`, forbidding overrides
    |
 help: Remove the override of `i`
 info: rule `override-of-final-method` is enabled by default
-60 |     f = None  # error: [override-of-final-method]
-61 |     g = None  # error: [override-of-final-method]
-62 |     h = None  # error: [override-of-final-method]
-   -     i = None  # error: [override-of-final-method]
-63 +       # error: [override-of-final-method]
-note: This is an unsafe fix and may change runtime behavior
 
 ```

crates/ty_python_semantic/resources/mdtest/snapshots/named_tuple.md_-_`NamedTuple`_-_NamedTuples_cannot_h…_(e2ed186fe2b2fc35).snap

@@ -0,0 +1,43 @@
+---
+source: crates/ty_test/src/lib.rs
+expression: snapshot
+---
+---
+mdtest name: named_tuple.md - `NamedTuple` - NamedTuples cannot have field names starting with underscores
+mdtest path: crates/ty_python_semantic/resources/mdtest/named_tuple.md
+---
+
+# Python source files
+
+## mdtest_snippet.py
+
+```
+ 1 | from typing import NamedTuple
+ 2 | 
+ 3 | class Foo(NamedTuple):
+ 4 |     # error: [invalid-named-tuple] "NamedTuple field `_bar` cannot start with an underscore"
+ 5 |     _bar: int
+ 6 | 
+ 7 | class Bar(NamedTuple):
+ 8 |     x: int
+ 9 | 
+10 | class Baz(Bar):
+11 |     _whatever: str  # `Baz` is not a NamedTuple class, so this is fine
+```
+
+# Diagnostics
+
+```
+error[invalid-named-tuple]: NamedTuple field name cannot start with an underscore
+ --> src/mdtest_snippet.py:5:5
+  |
+3 | class Foo(NamedTuple):
+4 |     # error: [invalid-named-tuple] "NamedTuple field `_bar` cannot start with an underscore"
+5 |     _bar: int
+  |     ^^^^^^^^^ Class definition will raise `TypeError` at runtime due to this field
+6 |
+7 | class Bar(NamedTuple):
+  |
+info: rule `invalid-named-tuple` is enabled by default
+
+```

crates/ty_python_semantic/resources/mdtest/subscript/tuple.md

@@ -329,6 +329,16 @@ reveal_type(tuple[int, str])  # revealed: <class 'tuple[int, str]'>
 reveal_type(tuple[int, ...])  # revealed: <class 'tuple[int, ...]'>
 ```
 
+```py
+from typing import Any
+
+def _(a: type[tuple], b: type[tuple[int]], c: type[tuple[int, ...]], d: type[tuple[Any, ...]]) -> None:
+    reveal_type(a)  # revealed: type[tuple[Unknown, ...]]
+    reveal_type(b)  # revealed: type[tuple[int]]
+    reveal_type(c)  # revealed: type[tuple[int, ...]]
+    reveal_type(d)  # revealed: type[tuple[Any, ...]]
+```
+
 ## Inheritance
 
 ```toml
@@ -392,7 +402,7 @@ class C(Tuple): ...
 reveal_mro(C)
 ```
 
-### Union subscript access
+## Union subscript access
 
 ```py
 def test(val: tuple[str] | tuple[int]):
@@ -402,7 +412,7 @@ def test2(val: tuple[str, None] | list[int | float]):
     reveal_type(val[0])  # revealed: str | int | float
 ```
 
-### Union subscript access with non-indexable type
+## Union subscript access with non-indexable type
 
 ```py
 def test3(val: tuple[str] | tuple[int] | int):
@@ -410,7 +420,7 @@ def test3(val: tuple[str] | tuple[int] | int):
     reveal_type(val[0])  # revealed: str | int | Unknown
 ```
 
-### Intersection subscript access
+## Intersection subscript access
 
 ```py
 from ty_extensions import Intersection

crates/ty_python_semantic/resources/mdtest/suppressions/type_ignore.md

@@ -85,6 +85,50 @@ a = test \
   + 2  # type: ignore
 ```
 
+## Interpolated strings
+
+```toml
+[environment]
+python-version = "3.14"
+```
+
+Suppressions for expressions within interpolated strings can be placed after the interpolated string
+if it's a single-line interpolation.
+
+```py
+a = f"""
+{test}
+"""  # type: ignore
+```
+
+For multiline-interpolation, put the ignore comment on the expression's start or end line:
+
+```py
+a = f"""
+{
+  10 /  # type: ignore
+  0
+}
+"""
+
+a = f"""
+{
+  10 /
+  0  # type: ignore
+}
+"""
+```
+
+But not at the end of the f-string:
+
+```py
+a = f"""
+{
+  10 / 0  # error: [division-by-zero]
+}
+"""  # error: [unused-ignore-comment]  # type: ignore
+```
+
 ## Codes
 
 Mypy supports `type: ignore[code]`. ty doesn't understand mypy's rule names. Therefore, ignore the

crates/ty_python_semantic/resources/mdtest/ty_extensions.md

@@ -398,7 +398,7 @@ the expression `str`:
 from ty_extensions import TypeOf, is_subtype_of, static_assert
 
 # This is incorrect and therefore fails with ...
-# error: "Static assertion error: argument of type `ty_extensions.ConstraintSet[never]` is statically known to be falsy"
+# error: "Static assertion error: argument of type `ty_extensions.ConstraintSet` is statically known to be falsy"
 static_assert(is_subtype_of(str, type[str]))
 
 # Correct, returns True:

crates/ty_python_semantic/resources/mdtest/type_of/generics.md

@@ -123,11 +123,11 @@ class A:
 A class `A` is a subtype of `type[T]` if any instance of `A` is a subtype of `T`.
 
 ```py
-from typing import Callable, Protocol
+from typing import Any, Callable, Protocol
 from ty_extensions import is_assignable_to, is_subtype_of, is_disjoint_from, static_assert
 
-class IntCallback(Protocol):
-    def __call__(self, *args, **kwargs) -> int: ...
+class Callback[T](Protocol):
+    def __call__(self, *args, **kwargs) -> T: ...
 
 def _[T](_: T):
     static_assert(not is_subtype_of(type[T], T))
@@ -141,8 +141,11 @@ def _[T](_: T):
     static_assert(is_assignable_to(type[T], Callable[..., T]))
     static_assert(not is_disjoint_from(type[T], Callable[..., T]))
 
-    static_assert(not is_assignable_to(type[T], IntCallback))
-    static_assert(not is_disjoint_from(type[T], IntCallback))
+    static_assert(is_assignable_to(type[T], Callable[..., T] | Callable[..., Any]))
+    static_assert(not is_disjoint_from(type[T], Callable[..., T] | Callable[..., Any]))
+
+    static_assert(not is_assignable_to(type[T], Callback[int]))
+    static_assert(not is_disjoint_from(type[T], Callback[int]))
 
 def _[T: int](_: T):
     static_assert(not is_subtype_of(type[T], T))
@@ -157,14 +160,23 @@ def _[T: int](_: T):
     static_assert(is_subtype_of(type[T], type[int]))
     static_assert(not is_disjoint_from(type[T], type[int]))
 
+    static_assert(is_subtype_of(type[T], type[int] | None))
+    static_assert(not is_disjoint_from(type[T], type[int] | None))
+
     static_assert(is_subtype_of(type[T], type[T]))
     static_assert(not is_disjoint_from(type[T], type[T]))
 
     static_assert(is_assignable_to(type[T], Callable[..., T]))
     static_assert(not is_disjoint_from(type[T], Callable[..., T]))
 
-    static_assert(is_assignable_to(type[T], IntCallback))
-    static_assert(not is_disjoint_from(type[T], IntCallback))
+    static_assert(is_assignable_to(type[T], Callable[..., T] | Callable[..., Any]))
+    static_assert(not is_disjoint_from(type[T], Callable[..., T] | Callable[..., Any]))
+
+    static_assert(is_assignable_to(type[T], Callback[int]))
+    static_assert(not is_disjoint_from(type[T], Callback[int]))
+
+    static_assert(is_assignable_to(type[T], Callback[int] | Callback[Any]))
+    static_assert(not is_disjoint_from(type[T], Callback[int] | Callback[Any]))
 
     static_assert(is_subtype_of(type[T], type[T] | None))
     static_assert(not is_disjoint_from(type[T], type[T] | None))
@@ -183,8 +195,14 @@ def _[T: (int, str)](_: T):
     static_assert(is_assignable_to(type[T], Callable[..., T]))
     static_assert(not is_disjoint_from(type[T], Callable[..., T]))
 
-    static_assert(not is_assignable_to(type[T], IntCallback))
-    static_assert(not is_disjoint_from(type[T], IntCallback))
+    static_assert(is_assignable_to(type[T], Callable[..., T] | Callable[..., Any]))
+    static_assert(not is_disjoint_from(type[T], Callable[..., T] | Callable[..., Any]))
+
+    static_assert(not is_assignable_to(type[T], Callback[int]))
+    static_assert(not is_disjoint_from(type[T], Callback[int]))
+
+    static_assert(is_assignable_to(type[T], Callback[int | str]))
+    static_assert(not is_disjoint_from(type[T], Callback[int] | Callback[str]))
 
     static_assert(is_subtype_of(type[T], type[T] | None))
     static_assert(not is_disjoint_from(type[T], type[T] | None))

crates/ty_python_semantic/resources/mdtest/type_properties/constraints.md

@@ -34,7 +34,7 @@ upper bound.
 
 ```py
 from typing import Any, final, Never, Sequence
-from ty_extensions import ConstraintSet
+from ty_extensions import ConstraintSet, static_assert
 
 class Super: ...
 class Base(Super): ...
@@ -44,8 +44,8 @@ class Sub(Base): ...
 class Unrelated: ...
 
 def _[T]() -> None:
-    # revealed: ty_extensions.ConstraintSet[(Sub ≤ T@_ ≤ Super)]
-    reveal_type(ConstraintSet.range(Sub, T, Super))
+    # (Sub ≤ T@_ ≤ Super)
+    ConstraintSet.range(Sub, T, Super)
 ```
 
 Every type is a supertype of `Never`, so a lower bound of `Never` is the same as having no lower
@@ -53,8 +53,8 @@ bound.
 
 ```py
 def _[T]() -> None:
-    # revealed: ty_extensions.ConstraintSet[(T@_ ≤ Base)]
-    reveal_type(ConstraintSet.range(Never, T, Base))
+    # (T@_ ≤ Base)
+    ConstraintSet.range(Never, T, Base)
 ```
 
 Similarly, every type is a subtype of `object`, so an upper bound of `object` is the same as having
@@ -62,8 +62,8 @@ no upper bound.
 
 ```py
 def _[T]() -> None:
-    # revealed: ty_extensions.ConstraintSet[(Base ≤ T@_)]
-    reveal_type(ConstraintSet.range(Base, T, object))
+    # (Base ≤ T@_)
+    ConstraintSet.range(Base, T, object)
 ```
 
 And a range constraint with a lower bound of `Never` and an upper bound of `object` allows the
@@ -74,8 +74,8 @@ of `object`.
 
 ```py
 def _[T]() -> None:
-    # revealed: ty_extensions.ConstraintSet[(T@_ = *)]
-    reveal_type(ConstraintSet.range(Never, T, object))
+    # (T@_ = *)
+    ConstraintSet.range(Never, T, object)
 ```
 
 If the lower bound and upper bounds are "inverted" (the upper bound is a subtype of the lower bound)
@@ -83,10 +83,8 @@ or incomparable, then there is no type that can satisfy the constraint.
 
 ```py
 def _[T]() -> None:
-    # revealed: ty_extensions.ConstraintSet[never]
-    reveal_type(ConstraintSet.range(Super, T, Sub))
-    # revealed: ty_extensions.ConstraintSet[never]
-    reveal_type(ConstraintSet.range(Base, T, Unrelated))
+    static_assert(not ConstraintSet.range(Super, T, Sub))
+    static_assert(not ConstraintSet.range(Base, T, Unrelated))
 ```
 
 The lower and upper bound can be the same type, in which case the typevar can only be specialized to
@@ -94,8 +92,8 @@ that specific type.
 
 ```py
 def _[T]() -> None:
-    # revealed: ty_extensions.ConstraintSet[(T@_ = Base)]
-    reveal_type(ConstraintSet.range(Base, T, Base))
+    # (T@_ = Base)
+    ConstraintSet.range(Base, T, Base)
 ```
 
 Constraints can only refer to fully static types, so the lower and upper bounds are transformed into
@@ -103,15 +101,21 @@ their bottom and top materializations, respectively.
 
 ```py
 def _[T]() -> None:
-    # revealed: ty_extensions.ConstraintSet[(Base ≤ T@_)]
-    reveal_type(ConstraintSet.range(Base, T, Any))
-    # revealed: ty_extensions.ConstraintSet[(Sequence[Base] ≤ T@_ ≤ Sequence[object])]
-    reveal_type(ConstraintSet.range(Sequence[Base], T, Sequence[Any]))
+    constraints = ConstraintSet.range(Base, T, Any)
+    expected = ConstraintSet.range(Base, T, object)
+    static_assert(constraints == expected)
 
-    # revealed: ty_extensions.ConstraintSet[(T@_ ≤ Base)]
-    reveal_type(ConstraintSet.range(Any, T, Base))
-    # revealed: ty_extensions.ConstraintSet[(Sequence[Never] ≤ T@_ ≤ Sequence[Base])]
-    reveal_type(ConstraintSet.range(Sequence[Any], T, Sequence[Base]))
+    constraints = ConstraintSet.range(Sequence[Base], T, Sequence[Any])
+    expected = ConstraintSet.range(Sequence[Base], T, Sequence[object])
+    static_assert(constraints == expected)
+
+    constraints = ConstraintSet.range(Any, T, Base)
+    expected = ConstraintSet.range(Never, T, Base)
+    static_assert(constraints == expected)
+
+    constraints = ConstraintSet.range(Sequence[Any], T, Sequence[Base])
+    expected = ConstraintSet.range(Sequence[Never], T, Sequence[Base])
+    static_assert(constraints == expected)
 ```
 
 ### Negated range
@@ -122,7 +126,7 @@ strict subtype of the lower bound, a strict supertype of the upper bound, or inc
 
 ```py
 from typing import Any, final, Never, Sequence
-from ty_extensions import ConstraintSet
+from ty_extensions import ConstraintSet, static_assert
 
 class Super: ...
 class Base(Super): ...
@@ -132,8 +136,8 @@ class Sub(Base): ...
 class Unrelated: ...
 
 def _[T]() -> None:
-    # revealed: ty_extensions.ConstraintSet[¬(Sub ≤ T@_ ≤ Super)]
-    reveal_type(~ConstraintSet.range(Sub, T, Super))
+    # ¬(Sub ≤ T@_ ≤ Super)
+    ~ConstraintSet.range(Sub, T, Super)
 ```
 
 Every type is a supertype of `Never`, so a lower bound of `Never` is the same as having no lower
@@ -141,8 +145,8 @@ bound.
 
 ```py
 def _[T]() -> None:
-    # revealed: ty_extensions.ConstraintSet[¬(T@_ ≤ Base)]
-    reveal_type(~ConstraintSet.range(Never, T, Base))
+    # ¬(T@_ ≤ Base)
+    ~ConstraintSet.range(Never, T, Base)
 ```
 
 Similarly, every type is a subtype of `object`, so an upper bound of `object` is the same as having
@@ -150,8 +154,8 @@ no upper bound.
 
 ```py
 def _[T]() -> None:
-    # revealed: ty_extensions.ConstraintSet[¬(Base ≤ T@_)]
-    reveal_type(~ConstraintSet.range(Base, T, object))
+    # ¬(Base ≤ T@_)
+    ~ConstraintSet.range(Base, T, object)
 ```
 
 And a negated range constraint with _both_ a lower bound of `Never` and an upper bound of `object`
@@ -159,8 +163,8 @@ cannot be satisfied at all.
 
 ```py
 def _[T]() -> None:
-    # revealed: ty_extensions.ConstraintSet[(T@_ ≠ *)]
-    reveal_type(~ConstraintSet.range(Never, T, object))
+    # (T@_ ≠ *)
+    ~ConstraintSet.range(Never, T, object)
 ```
 
 If the lower bound and upper bounds are "inverted" (the upper bound is a subtype of the lower bound)
@@ -168,10 +172,8 @@ or incomparable, then the negated range constraint can always be satisfied.
 
 ```py
 def _[T]() -> None:
-    # revealed: ty_extensions.ConstraintSet[always]
-    reveal_type(~ConstraintSet.range(Super, T, Sub))
-    # revealed: ty_extensions.ConstraintSet[always]
-    reveal_type(~ConstraintSet.range(Base, T, Unrelated))
+    static_assert(~ConstraintSet.range(Super, T, Sub))
+    static_assert(~ConstraintSet.range(Base, T, Unrelated))
 ```
 
 The lower and upper bound can be the same type, in which case the typevar can be specialized to any
@@ -179,8 +181,8 @@ type other than that specific type.
 
 ```py
 def _[T]() -> None:
-    # revealed: ty_extensions.ConstraintSet[(T@_ ≠ Base)]
-    reveal_type(~ConstraintSet.range(Base, T, Base))
+    # (T@_ ≠ Base)
+    ~ConstraintSet.range(Base, T, Base)
 ```
 
 Constraints can only refer to fully static types, so the lower and upper bounds are transformed into
@@ -188,15 +190,21 @@ their bottom and top materializations, respectively.
 
 ```py
 def _[T]() -> None:
-    # revealed: ty_extensions.ConstraintSet[¬(Base ≤ T@_)]
-    reveal_type(~ConstraintSet.range(Base, T, Any))
-    # revealed: ty_extensions.ConstraintSet[¬(Sequence[Base] ≤ T@_ ≤ Sequence[object])]
-    reveal_type(~ConstraintSet.range(Sequence[Base], T, Sequence[Any]))
+    constraints = ~ConstraintSet.range(Base, T, Any)
+    expected = ~ConstraintSet.range(Base, T, object)
+    static_assert(constraints == expected)
 
-    # revealed: ty_extensions.ConstraintSet[¬(T@_ ≤ Base)]
-    reveal_type(~ConstraintSet.range(Any, T, Base))
-    # revealed: ty_extensions.ConstraintSet[¬(Sequence[Never] ≤ T@_ ≤ Sequence[Base])]
-    reveal_type(~ConstraintSet.range(Sequence[Any], T, Sequence[Base]))
+    constraints = ~ConstraintSet.range(Sequence[Base], T, Sequence[Any])
+    expected = ~ConstraintSet.range(Sequence[Base], T, Sequence[object])
+    static_assert(constraints == expected)
+
+    constraints = ~ConstraintSet.range(Any, T, Base)
+    expected = ~ConstraintSet.range(Never, T, Base)
+    static_assert(constraints == expected)
+
+    constraints = ~ConstraintSet.range(Sequence[Any], T, Sequence[Base])
+    expected = ~ConstraintSet.range(Sequence[Never], T, Sequence[Base])
+    static_assert(constraints == expected)
 ```
 
 ## Intersection
@@ -218,10 +226,10 @@ We cannot simplify the intersection of constraints that refer to different typev
 
 ```py
 def _[T, U]() -> None:
-    # revealed: ty_extensions.ConstraintSet[((Sub ≤ T@_ ≤ Base) ∧ (Sub ≤ U@_ ≤ Base))]
-    reveal_type(ConstraintSet.range(Sub, T, Base) & ConstraintSet.range(Sub, U, Base))
-    # revealed: ty_extensions.ConstraintSet[(¬(Sub ≤ T@_ ≤ Base) ∧ ¬(Sub ≤ U@_ ≤ Base))]
-    reveal_type(~ConstraintSet.range(Sub, T, Base) & ~ConstraintSet.range(Sub, U, Base))
+    # (Sub ≤ T@_ ≤ Base) ∧ (Sub ≤ U@_ ≤ Base)
+    ConstraintSet.range(Sub, T, Base) & ConstraintSet.range(Sub, U, Base)
+    # ¬(Sub ≤ T@_ ≤ Base) ∧ ¬(Sub ≤ U@_ ≤ Base)
+    ~ConstraintSet.range(Sub, T, Base) & ~ConstraintSet.range(Sub, U, Base)
 ```
 
 ### Intersection of two ranges
@@ -230,7 +238,7 @@ The intersection of two ranges is where the ranges "overlap".
 
 ```py
 from typing import final
-from ty_extensions import ConstraintSet
+from ty_extensions import ConstraintSet, static_assert
 
 class Super: ...
 class Base(Super): ...
@@ -241,24 +249,29 @@ class SubSub(Sub): ...
 class Unrelated: ...
 
 def _[T]() -> None:
-    # revealed: ty_extensions.ConstraintSet[(Sub ≤ T@_ ≤ Base)]
-    reveal_type(ConstraintSet.range(SubSub, T, Base) & ConstraintSet.range(Sub, T, Super))
-    # revealed: ty_extensions.ConstraintSet[(Sub ≤ T@_ ≤ Base)]
-    reveal_type(ConstraintSet.range(SubSub, T, Super) & ConstraintSet.range(Sub, T, Base))
-    # revealed: ty_extensions.ConstraintSet[(T@_ = Base)]
-    reveal_type(ConstraintSet.range(Sub, T, Base) & ConstraintSet.range(Base, T, Super))
-    # revealed: ty_extensions.ConstraintSet[(Sub ≤ T@_ ≤ Super)]
-    reveal_type(ConstraintSet.range(Sub, T, Super) & ConstraintSet.range(Sub, T, Super))
+    constraints = ConstraintSet.range(SubSub, T, Base) & ConstraintSet.range(Sub, T, Super)
+    expected = ConstraintSet.range(Sub, T, Base)
+    static_assert(constraints == expected)
+
+    constraints = ConstraintSet.range(SubSub, T, Super) & ConstraintSet.range(Sub, T, Base)
+    expected = ConstraintSet.range(Sub, T, Base)
+    static_assert(constraints == expected)
+
+    constraints = ConstraintSet.range(Sub, T, Base) & ConstraintSet.range(Base, T, Super)
+    expected = ConstraintSet.range(Base, T, Base)
+    static_assert(constraints == expected)
+
+    constraints = ConstraintSet.range(Sub, T, Super) & ConstraintSet.range(Sub, T, Super)
+    expected = ConstraintSet.range(Sub, T, Super)
+    static_assert(constraints == expected)
 ```
 
 If they don't overlap, the intersection is empty.
 
 ```py
 def _[T]() -> None:
-    # revealed: ty_extensions.ConstraintSet[never]
-    reveal_type(ConstraintSet.range(SubSub, T, Sub) & ConstraintSet.range(Base, T, Super))
-    # revealed: ty_extensions.ConstraintSet[never]
-    reveal_type(ConstraintSet.range(SubSub, T, Sub) & ConstraintSet.range(Unrelated, T, object))
+    static_assert(not ConstraintSet.range(SubSub, T, Sub) & ConstraintSet.range(Base, T, Super))
+    static_assert(not ConstraintSet.range(SubSub, T, Sub) & ConstraintSet.range(Unrelated, T, object))
 ```
 
 Expanding on this, when intersecting two upper bounds constraints (`(T ≤ Base) ∧ (T ≤ Other)`), we
@@ -267,23 +280,17 @@ satisfy their intersection `T ≤ Base & Other`, and vice versa.
 
 ```py
 from typing import Never
-from ty_extensions import Intersection, static_assert
+from ty_extensions import Intersection
 
 # This is not final, so it's possible for a subclass to inherit from both Base and Other.
 class Other: ...
 
 def upper_bounds[T]():
+    # (T@upper_bounds ≤ Base & Other)
     intersection_type = ConstraintSet.range(Never, T, Intersection[Base, Other])
-    # revealed: ty_extensions.ConstraintSet[(T@upper_bounds ≤ Base & Other)]
-    reveal_type(intersection_type)
-
+    # (T@upper_bounds ≤ Base) ∧ (T@upper_bounds ≤ Other)
     intersection_constraint = ConstraintSet.range(Never, T, Base) & ConstraintSet.range(Never, T, Other)
-    # revealed: ty_extensions.ConstraintSet[(T@upper_bounds ≤ Base & Other)]
-    reveal_type(intersection_constraint)
-
-    # The two constraint sets are equivalent; each satisfies the other.
-    static_assert(intersection_type.satisfies(intersection_constraint))
-    static_assert(intersection_constraint.satisfies(intersection_type))
+    static_assert(intersection_type == intersection_constraint)
 ```
 
 For an intersection of two lower bounds constraints (`(Base ≤ T) ∧ (Other ≤ T)`), we union the lower
@@ -292,17 +299,11 @@ bounds. Any type that satisfies both `Base ≤ T` and `Other ≤ T` must necessa
 
 ```py
 def lower_bounds[T]():
+    # (Base | Other ≤ T@lower_bounds)
     union_type = ConstraintSet.range(Base | Other, T, object)
-    # revealed: ty_extensions.ConstraintSet[(Base | Other ≤ T@lower_bounds)]
-    reveal_type(union_type)
-
+    # (Base ≤ T@upper_bounds) ∧ (Other ≤ T@upper_bounds)
     intersection_constraint = ConstraintSet.range(Base, T, object) & ConstraintSet.range(Other, T, object)
-    # revealed: ty_extensions.ConstraintSet[(Base | Other ≤ T@lower_bounds)]
-    reveal_type(intersection_constraint)
-
-    # The two constraint sets are equivalent; each satisfies the other.
-    static_assert(union_type.satisfies(intersection_constraint))
-    static_assert(intersection_constraint.satisfies(union_type))
+    static_assert(union_type == intersection_constraint)
 ```
 
 ### Intersection of a range and a negated range
@@ -313,7 +314,7 @@ the intersection as removing the hole from the range constraint.
 
 ```py
 from typing import final, Never
-from ty_extensions import ConstraintSet
+from ty_extensions import ConstraintSet, static_assert
 
 class Super: ...
 class Base(Super): ...
@@ -328,10 +329,8 @@ If the negative range completely contains the positive range, then the intersect
 
 ```py
 def _[T]() -> None:
-    # revealed: ty_extensions.ConstraintSet[never]
-    reveal_type(ConstraintSet.range(Sub, T, Base) & ~ConstraintSet.range(SubSub, T, Super))
-    # revealed: ty_extensions.ConstraintSet[never]
-    reveal_type(ConstraintSet.range(Sub, T, Base) & ~ConstraintSet.range(Sub, T, Base))
+    static_assert(not ConstraintSet.range(Sub, T, Base) & ~ConstraintSet.range(SubSub, T, Super))
+    static_assert(not ConstraintSet.range(Sub, T, Base) & ~ConstraintSet.range(Sub, T, Base))
 ```
 
 If the negative range is disjoint from the positive range, the negative range doesn't remove
@@ -339,12 +338,17 @@ anything; the intersection is the positive range.
 
 ```py
 def _[T]() -> None:
-    # revealed: ty_extensions.ConstraintSet[(Sub ≤ T@_ ≤ Base)]
-    reveal_type(ConstraintSet.range(Sub, T, Base) & ~ConstraintSet.range(Never, T, Unrelated))
-    # revealed: ty_extensions.ConstraintSet[(SubSub ≤ T@_ ≤ Sub)]
-    reveal_type(ConstraintSet.range(SubSub, T, Sub) & ~ConstraintSet.range(Base, T, Super))
-    # revealed: ty_extensions.ConstraintSet[(Base ≤ T@_ ≤ Super)]
-    reveal_type(ConstraintSet.range(Base, T, Super) & ~ConstraintSet.range(SubSub, T, Sub))
+    constraints = ConstraintSet.range(Sub, T, Base) & ~ConstraintSet.range(Never, T, Unrelated)
+    expected = ConstraintSet.range(Sub, T, Base)
+    static_assert(constraints == expected)
+
+    constraints = ConstraintSet.range(SubSub, T, Sub) & ~ConstraintSet.range(Base, T, Super)
+    expected = ConstraintSet.range(SubSub, T, Sub)
+    static_assert(constraints == expected)
+
+    constraints = ConstraintSet.range(Base, T, Super) & ~ConstraintSet.range(SubSub, T, Sub)
+    expected = ConstraintSet.range(Base, T, Super)
+    static_assert(constraints == expected)
 ```
 
 Otherwise we clip the negative constraint to the mininum range that overlaps with the positive
@@ -352,10 +356,9 @@ range.
 
 ```py
 def _[T]() -> None:
-    # revealed: ty_extensions.ConstraintSet[((SubSub ≤ T@_ ≤ Base) ∧ ¬(Sub ≤ T@_ ≤ Base))]
-    reveal_type(ConstraintSet.range(SubSub, T, Base) & ~ConstraintSet.range(Sub, T, Super))
-    # revealed: ty_extensions.ConstraintSet[((SubSub ≤ T@_ ≤ Super) ∧ ¬(Sub ≤ T@_ ≤ Base))]
-    reveal_type(ConstraintSet.range(SubSub, T, Super) & ~ConstraintSet.range(Sub, T, Base))
+    constraints = ConstraintSet.range(SubSub, T, Base) & ~ConstraintSet.range(Sub, T, Super)
+    expected = ConstraintSet.range(SubSub, T, Base) & ~ConstraintSet.range(Sub, T, Base)
+    static_assert(constraints == expected)
 ```
 
 ### Intersection of two negated ranges
@@ -365,7 +368,7 @@ smaller constraint. For negated ranges, the smaller constraint is the one with t
 
 ```py
 from typing import final
-from ty_extensions import ConstraintSet
+from ty_extensions import ConstraintSet, static_assert
 
 class Super: ...
 class Base(Super): ...
@@ -376,22 +379,25 @@ class SubSub(Sub): ...
 class Unrelated: ...
 
 def _[T]() -> None:
-    # revealed: ty_extensions.ConstraintSet[¬(SubSub ≤ T@_ ≤ Super)]
-    reveal_type(~ConstraintSet.range(SubSub, T, Super) & ~ConstraintSet.range(Sub, T, Base))
-    # revealed: ty_extensions.ConstraintSet[¬(Sub ≤ T@_ ≤ Super)]
-    reveal_type(~ConstraintSet.range(Sub, T, Super) & ~ConstraintSet.range(Sub, T, Super))
+    constraints = ~ConstraintSet.range(SubSub, T, Super) & ~ConstraintSet.range(Sub, T, Base)
+    expected = ~ConstraintSet.range(SubSub, T, Super)
+    static_assert(constraints == expected)
+
+    constraints = ~ConstraintSet.range(Sub, T, Super) & ~ConstraintSet.range(Sub, T, Super)
+    expected = ~ConstraintSet.range(Sub, T, Super)
+    static_assert(constraints == expected)
 ```
 
 Otherwise, the intersection cannot be simplified.
 
 ```py
 def _[T]() -> None:
-    # revealed: ty_extensions.ConstraintSet[(¬(Base ≤ T@_ ≤ Super) ∧ ¬(Sub ≤ T@_ ≤ Base))]
-    reveal_type(~ConstraintSet.range(Sub, T, Base) & ~ConstraintSet.range(Base, T, Super))
-    # revealed: ty_extensions.ConstraintSet[(¬(Base ≤ T@_ ≤ Super) ∧ ¬(SubSub ≤ T@_ ≤ Sub))]
-    reveal_type(~ConstraintSet.range(SubSub, T, Sub) & ~ConstraintSet.range(Base, T, Super))
-    # revealed: ty_extensions.ConstraintSet[(¬(SubSub ≤ T@_ ≤ Sub) ∧ ¬(Unrelated ≤ T@_))]
-    reveal_type(~ConstraintSet.range(SubSub, T, Sub) & ~ConstraintSet.range(Unrelated, T, object))
+    # ¬(Base ≤ T@_ ≤ Super) ∧ ¬(Sub ≤ T@_ ≤ Base))
+    ~ConstraintSet.range(Sub, T, Base) & ~ConstraintSet.range(Base, T, Super)
+    # ¬(Base ≤ T@_ ≤ Super) ∧ ¬(SubSub ≤ T@_ ≤ Sub))
+    ~ConstraintSet.range(SubSub, T, Sub) & ~ConstraintSet.range(Base, T, Super)
+    # ¬(SubSub ≤ T@_ ≤ Sub) ∧ ¬(Unrelated ≤ T@_)
+    ~ConstraintSet.range(SubSub, T, Sub) & ~ConstraintSet.range(Unrelated, T, object)
 ```
 
 In particular, the following does not simplify, even though it seems like it could simplify to
@@ -408,8 +414,8 @@ way.
 
 ```py
 def _[T]() -> None:
-    # revealed: ty_extensions.ConstraintSet[(¬(Sub ≤ T@_ ≤ Super) ∧ ¬(SubSub ≤ T@_ ≤ Base))]
-    reveal_type(~ConstraintSet.range(SubSub, T, Base) & ~ConstraintSet.range(Sub, T, Super))
+    # (¬(Sub ≤ T@_ ≤ Super) ∧ ¬(SubSub ≤ T@_ ≤ Base))
+    ~ConstraintSet.range(SubSub, T, Base) & ~ConstraintSet.range(Sub, T, Super)
 ```
 
 ## Union
@@ -431,10 +437,10 @@ We cannot simplify the union of constraints that refer to different typevars.
 
 ```py
 def _[T, U]() -> None:
-    # revealed: ty_extensions.ConstraintSet[(Sub ≤ T@_ ≤ Base) ∨ (Sub ≤ U@_ ≤ Base)]
-    reveal_type(ConstraintSet.range(Sub, T, Base) | ConstraintSet.range(Sub, U, Base))
-    # revealed: ty_extensions.ConstraintSet[¬(Sub ≤ T@_ ≤ Base) ∨ ¬(Sub ≤ U@_ ≤ Base)]
-    reveal_type(~ConstraintSet.range(Sub, T, Base) | ~ConstraintSet.range(Sub, U, Base))
+    # (Sub ≤ T@_ ≤ Base) ∨ (Sub ≤ U@_ ≤ Base)
+    ConstraintSet.range(Sub, T, Base) | ConstraintSet.range(Sub, U, Base)
+    # ¬(Sub ≤ T@_ ≤ Base) ∨ ¬(Sub ≤ U@_ ≤ Base)
+    ~ConstraintSet.range(Sub, T, Base) | ~ConstraintSet.range(Sub, U, Base)
 ```
 
 ### Union of two ranges
@@ -444,7 +450,7 @@ bounds.
 
 ```py
 from typing import final
-from ty_extensions import ConstraintSet
+from ty_extensions import ConstraintSet, static_assert
 
 class Super: ...
 class Base(Super): ...
@@ -455,22 +461,25 @@ class SubSub(Sub): ...
 class Unrelated: ...
 
 def _[T]() -> None:
-    # revealed: ty_extensions.ConstraintSet[(SubSub ≤ T@_ ≤ Super)]
-    reveal_type(ConstraintSet.range(SubSub, T, Super) | ConstraintSet.range(Sub, T, Base))
-    # revealed: ty_extensions.ConstraintSet[(Sub ≤ T@_ ≤ Super)]
-    reveal_type(ConstraintSet.range(Sub, T, Super) | ConstraintSet.range(Sub, T, Super))
+    constraints = ConstraintSet.range(SubSub, T, Super) | ConstraintSet.range(Sub, T, Base)
+    expected = ConstraintSet.range(SubSub, T, Super)
+    static_assert(constraints == expected)
+
+    constraints = ConstraintSet.range(Sub, T, Super) | ConstraintSet.range(Sub, T, Super)
+    expected = ConstraintSet.range(Sub, T, Super)
+    static_assert(constraints == expected)
 ```
 
 Otherwise, the union cannot be simplified.
 
 ```py
 def _[T]() -> None:
-    # revealed: ty_extensions.ConstraintSet[(Base ≤ T@_ ≤ Super) ∨ (Sub ≤ T@_ ≤ Base)]
-    reveal_type(ConstraintSet.range(Sub, T, Base) | ConstraintSet.range(Base, T, Super))
-    # revealed: ty_extensions.ConstraintSet[(Base ≤ T@_ ≤ Super) ∨ (SubSub ≤ T@_ ≤ Sub)]
-    reveal_type(ConstraintSet.range(SubSub, T, Sub) | ConstraintSet.range(Base, T, Super))
-    # revealed: ty_extensions.ConstraintSet[(SubSub ≤ T@_ ≤ Sub) ∨ (Unrelated ≤ T@_)]
-    reveal_type(ConstraintSet.range(SubSub, T, Sub) | ConstraintSet.range(Unrelated, T, object))
+    # (Base ≤ T@_ ≤ Super) ∨ (Sub ≤ T@_ ≤ Base)
+    ConstraintSet.range(Sub, T, Base) | ConstraintSet.range(Base, T, Super)
+    # (Base ≤ T@_ ≤ Super) ∨ (SubSub ≤ T@_ ≤ Sub)
+    ConstraintSet.range(SubSub, T, Sub) | ConstraintSet.range(Base, T, Super)
+    # (SubSub ≤ T@_ ≤ Sub) ∨ (Unrelated ≤ T@_)
+    ConstraintSet.range(SubSub, T, Sub) | ConstraintSet.range(Unrelated, T, object)
 ```
 
 In particular, the following does not simplify, even though it seems like it could simplify to
@@ -485,8 +494,8 @@ not include `Sub`. That means it should not be in the union. Since that type _is
 
 ```py
 def _[T]() -> None:
-    # revealed: ty_extensions.ConstraintSet[(Sub ≤ T@_ ≤ Super) ∨ (SubSub ≤ T@_ ≤ Base)]
-    reveal_type(ConstraintSet.range(SubSub, T, Base) | ConstraintSet.range(Sub, T, Super))
+    # (Sub ≤ T@_ ≤ Super) ∨ (SubSub ≤ T@_ ≤ Base)
+    ConstraintSet.range(SubSub, T, Base) | ConstraintSet.range(Sub, T, Super)
 ```
 
 The union of two upper bound constraints (`(T ≤ Base) ∨ (T ≤ Other)`) is different than the single
@@ -496,24 +505,18 @@ that satisfies the union constraint satisfies the union type.
 
 ```py
 from typing import Never
-from ty_extensions import static_assert
 
 # This is not final, so it's possible for a subclass to inherit from both Base and Other.
 class Other: ...
 
 def union[T]():
+    # (T@union ≤ Base | Other)
     union_type = ConstraintSet.range(Never, T, Base | Other)
-    # revealed: ty_extensions.ConstraintSet[(T@union ≤ Base | Other)]
-    reveal_type(union_type)
-
+    # (T@union ≤ Base) ∨ (T@union ≤ Other)
     union_constraint = ConstraintSet.range(Never, T, Base) | ConstraintSet.range(Never, T, Other)
-    # revealed: ty_extensions.ConstraintSet[(T@union ≤ Base) ∨ (T@union ≤ Other)]
-    reveal_type(union_constraint)
 
     # (T = Base | Other) satisfies (T ≤ Base | Other) but not (T ≤ Base ∨ T ≤ Other)
     specialization = ConstraintSet.range(Base | Other, T, Base | Other)
-    # revealed: ty_extensions.ConstraintSet[(T@union = Base | Other)]
-    reveal_type(specialization)
     static_assert(specialization.satisfies(union_type))
     static_assert(not specialization.satisfies(union_constraint))
 
@@ -528,18 +531,13 @@ satisfies the union constraint (`(Base ≤ T) ∨ (Other ≤ T)`) but not the un
 
 ```py
 def union[T]():
+    # (Base | Other ≤ T@union)
     union_type = ConstraintSet.range(Base | Other, T, object)
-    # revealed: ty_extensions.ConstraintSet[(Base | Other ≤ T@union)]
-    reveal_type(union_type)
-
+    # (Base ≤ T@union) ∨ (Other ≤ T@union)
     union_constraint = ConstraintSet.range(Base, T, object) | ConstraintSet.range(Other, T, object)
-    # revealed: ty_extensions.ConstraintSet[(Base ≤ T@union) ∨ (Other ≤ T@union)]
-    reveal_type(union_constraint)
 
     # (T = Base) satisfies (Base ≤ T ∨ Other ≤ T) but not (Base | Other ≤ T)
     specialization = ConstraintSet.range(Base, T, Base)
-    # revealed: ty_extensions.ConstraintSet[(T@union = Base)]
-    reveal_type(specialization)
     static_assert(not specialization.satisfies(union_type))
     static_assert(specialization.satisfies(union_constraint))
 
@@ -556,7 +554,7 @@ the union as filling part of the hole with the types from the range constraint.
 
 ```py
 from typing import final, Never
-from ty_extensions import ConstraintSet
+from ty_extensions import ConstraintSet, static_assert
 
 class Super: ...
 class Base(Super): ...
@@ -571,10 +569,8 @@ If the positive range completely contains the negative range, then the union is
 
 ```py
 def _[T]() -> None:
-    # revealed: ty_extensions.ConstraintSet[always]
-    reveal_type(~ConstraintSet.range(Sub, T, Base) | ConstraintSet.range(SubSub, T, Super))
-    # revealed: ty_extensions.ConstraintSet[always]
-    reveal_type(~ConstraintSet.range(Sub, T, Base) | ConstraintSet.range(Sub, T, Base))
+    static_assert(~ConstraintSet.range(Sub, T, Base) | ConstraintSet.range(SubSub, T, Super))
+    static_assert(~ConstraintSet.range(Sub, T, Base) | ConstraintSet.range(Sub, T, Base))
 ```
 
 If the negative range is disjoint from the positive range, the positive range doesn't add anything;
@@ -582,12 +578,17 @@ the union is the negative range.
 
 ```py
 def _[T]() -> None:
-    # revealed: ty_extensions.ConstraintSet[¬(Sub ≤ T@_ ≤ Base)]
-    reveal_type(~ConstraintSet.range(Sub, T, Base) | ConstraintSet.range(Never, T, Unrelated))
-    # revealed: ty_extensions.ConstraintSet[¬(SubSub ≤ T@_ ≤ Sub)]
-    reveal_type(~ConstraintSet.range(SubSub, T, Sub) | ConstraintSet.range(Base, T, Super))
-    # revealed: ty_extensions.ConstraintSet[¬(Base ≤ T@_ ≤ Super)]
-    reveal_type(~ConstraintSet.range(Base, T, Super) | ConstraintSet.range(SubSub, T, Sub))
+    constraints = ~ConstraintSet.range(Sub, T, Base) | ConstraintSet.range(Never, T, Unrelated)
+    expected = ~ConstraintSet.range(Sub, T, Base)
+    static_assert(constraints == expected)
+
+    constraints = ~ConstraintSet.range(SubSub, T, Sub) | ConstraintSet.range(Base, T, Super)
+    expected = ~ConstraintSet.range(SubSub, T, Sub)
+    static_assert(constraints == expected)
+
+    constraints = ~ConstraintSet.range(Base, T, Super) | ConstraintSet.range(SubSub, T, Sub)
+    expected = ~ConstraintSet.range(Base, T, Super)
+    static_assert(constraints == expected)
 ```
 
 Otherwise we clip the positive constraint to the mininum range that overlaps with the negative
@@ -595,10 +596,9 @@ range.
 
 ```py
 def _[T]() -> None:
-    # revealed: ty_extensions.ConstraintSet[(Sub ≤ T@_ ≤ Base) ∨ ¬(SubSub ≤ T@_ ≤ Base)]
-    reveal_type(~ConstraintSet.range(SubSub, T, Base) | ConstraintSet.range(Sub, T, Super))
-    # revealed: ty_extensions.ConstraintSet[(Sub ≤ T@_ ≤ Base) ∨ ¬(SubSub ≤ T@_ ≤ Super)]
-    reveal_type(~ConstraintSet.range(SubSub, T, Super) | ConstraintSet.range(Sub, T, Base))
+    constraints = ~ConstraintSet.range(SubSub, T, Base) | ConstraintSet.range(Sub, T, Super)
+    expected = ~ConstraintSet.range(SubSub, T, Base) | ConstraintSet.range(Sub, T, Base)
+    static_assert(constraints == expected)
 ```
 
 ### Union of two negated ranges
@@ -607,7 +607,7 @@ The union of two negated ranges has a hole where the ranges "overlap".
 
 ```py
 from typing import final
-from ty_extensions import ConstraintSet
+from ty_extensions import ConstraintSet, static_assert
 
 class Super: ...
 class Base(Super): ...
@@ -618,24 +618,29 @@ class SubSub(Sub): ...
 class Unrelated: ...
 
 def _[T]() -> None:
-    # revealed: ty_extensions.ConstraintSet[¬(Sub ≤ T@_ ≤ Base)]
-    reveal_type(~ConstraintSet.range(SubSub, T, Base) | ~ConstraintSet.range(Sub, T, Super))
-    # revealed: ty_extensions.ConstraintSet[¬(Sub ≤ T@_ ≤ Base)]
-    reveal_type(~ConstraintSet.range(SubSub, T, Super) | ~ConstraintSet.range(Sub, T, Base))
-    # revealed: ty_extensions.ConstraintSet[(T@_ ≠ Base)]
-    reveal_type(~ConstraintSet.range(Sub, T, Base) | ~ConstraintSet.range(Base, T, Super))
-    # revealed: ty_extensions.ConstraintSet[¬(Sub ≤ T@_ ≤ Super)]
-    reveal_type(~ConstraintSet.range(Sub, T, Super) | ~ConstraintSet.range(Sub, T, Super))
+    constraints = ~ConstraintSet.range(SubSub, T, Base) | ~ConstraintSet.range(Sub, T, Super)
+    expected = ~ConstraintSet.range(Sub, T, Base)
+    static_assert(constraints == expected)
+
+    constraints = ~ConstraintSet.range(SubSub, T, Super) | ~ConstraintSet.range(Sub, T, Base)
+    expected = ~ConstraintSet.range(Sub, T, Base)
+    static_assert(constraints == expected)
+
+    constraints = ~ConstraintSet.range(Sub, T, Base) | ~ConstraintSet.range(Base, T, Super)
+    expected = ~ConstraintSet.range(Base, T, Base)
+    static_assert(constraints == expected)
+
+    constraints = ~ConstraintSet.range(Sub, T, Super) | ~ConstraintSet.range(Sub, T, Super)
+    expected = ~ConstraintSet.range(Sub, T, Super)
+    static_assert(constraints == expected)
 ```
 
 If the holes don't overlap, the union is always satisfied.
 
 ```py
 def _[T]() -> None:
-    # revealed: ty_extensions.ConstraintSet[always]
-    reveal_type(~ConstraintSet.range(SubSub, T, Sub) | ~ConstraintSet.range(Base, T, Super))
-    # revealed: ty_extensions.ConstraintSet[always]
-    reveal_type(~ConstraintSet.range(SubSub, T, Sub) | ~ConstraintSet.range(Unrelated, T, object))
+    static_assert(~ConstraintSet.range(SubSub, T, Sub) | ~ConstraintSet.range(Base, T, Super))
+    static_assert(~ConstraintSet.range(SubSub, T, Sub) | ~ConstraintSet.range(Unrelated, T, object))
 ```
 
 ## Negation
@@ -644,21 +649,21 @@ def _[T]() -> None:
 
 ```py
 from typing import Never
-from ty_extensions import ConstraintSet
+from ty_extensions import ConstraintSet, static_assert
 
 class Super: ...
 class Base(Super): ...
 class Sub(Base): ...
 
 def _[T]() -> None:
-    # revealed: ty_extensions.ConstraintSet[¬(Sub ≤ T@_ ≤ Base)]
-    reveal_type(~ConstraintSet.range(Sub, T, Base))
-    # revealed: ty_extensions.ConstraintSet[¬(T@_ ≤ Base)]
-    reveal_type(~ConstraintSet.range(Never, T, Base))
-    # revealed: ty_extensions.ConstraintSet[¬(Sub ≤ T@_)]
-    reveal_type(~ConstraintSet.range(Sub, T, object))
-    # revealed: ty_extensions.ConstraintSet[(T@_ ≠ *)]
-    reveal_type(~ConstraintSet.range(Never, T, object))
+    # ¬(Sub ≤ T@_ ≤ Base)
+    ~ConstraintSet.range(Sub, T, Base)
+    # ¬(T@_ ≤ Base)
+    ~ConstraintSet.range(Never, T, Base)
+    # ¬(Sub ≤ T@_)
+    ~ConstraintSet.range(Sub, T, object)
+    # (T@_ ≠ *)
+    ~ConstraintSet.range(Never, T, object)
 ```
 
 The union of a range constraint and its negation should always be satisfiable.
@@ -666,15 +671,14 @@ The union of a range constraint and its negation should always be satisfiable.
 ```py
 def _[T]() -> None:
     constraint = ConstraintSet.range(Sub, T, Base)
-    # revealed: ty_extensions.ConstraintSet[always]
-    reveal_type(constraint | ~constraint)
+    static_assert(constraint | ~constraint)
 ```
 
 ### Negation of constraints involving two variables
 
 ```py
 from typing import final, Never
-from ty_extensions import ConstraintSet
+from ty_extensions import ConstraintSet, static_assert
 
 class Base: ...
 
@@ -682,8 +686,8 @@ class Base: ...
 class Unrelated: ...
 
 def _[T, U]() -> None:
-    # revealed: ty_extensions.ConstraintSet[¬(T@_ ≤ Base) ∨ ¬(U@_ ≤ Base)]
-    reveal_type(~(ConstraintSet.range(Never, T, Base) & ConstraintSet.range(Never, U, Base)))
+    # ¬(T@_ ≤ Base) ∨ ¬(U@_ ≤ Base)
+    ~(ConstraintSet.range(Never, T, Base) & ConstraintSet.range(Never, U, Base))
 ```
 
 The union of a constraint and its negation should always be satisfiable.
@@ -691,150 +695,91 @@ The union of a constraint and its negation should always be satisfiable.
 ```py
 def _[T, U]() -> None:
     c1 = ConstraintSet.range(Never, T, Base) & ConstraintSet.range(Never, U, Base)
-    # revealed: ty_extensions.ConstraintSet[always]
-    reveal_type(c1 | ~c1)
-    # revealed: ty_extensions.ConstraintSet[always]
-    reveal_type(~c1 | c1)
+    static_assert(c1 | ~c1)
+    static_assert(~c1 | c1)
 
     c2 = ConstraintSet.range(Unrelated, T, object) & ConstraintSet.range(Unrelated, U, object)
-    # revealed: ty_extensions.ConstraintSet[always]
-    reveal_type(c2 | ~c2)
-    # revealed: ty_extensions.ConstraintSet[always]
-    reveal_type(~c2 | c2)
+    static_assert(c2 | ~c2)
+    static_assert(~c2 | c2)
 
     union = c1 | c2
-    # revealed: ty_extensions.ConstraintSet[always]
-    reveal_type(union | ~union)
-    # revealed: ty_extensions.ConstraintSet[always]
-    reveal_type(~union | union)
+    static_assert(union | ~union)
+    static_assert(~union | union)
 ```
 
 ## Typevar ordering
 
 Constraints can relate two typevars — i.e., `S ≤ T`. We could encode that in one of two ways:
 `Never ≤ S ≤ T` or `S ≤ T ≤ object`. In other words, we can decide whether `S` or `T` is the typevar
-being constrained. The other is then the lower or upper bound of the constraint.
-
-To handle this, we enforce an arbitrary ordering on typevars, and always place the constraint on the
-"earlier" typevar. For the example above, that does not change how the constraint is displayed,
-since we always hide `Never` lower bounds and `object` upper bounds.
+being constrained. The other is then the lower or upper bound of the constraint. To handle this, we
+enforce an arbitrary ordering on typevars, and always place the constraint on the "earlier" typevar.
 
 ```py
 from typing import Never
-from ty_extensions import ConstraintSet
+from ty_extensions import ConstraintSet, static_assert
 
 def f[S, T]():
-    # revealed: ty_extensions.ConstraintSet[(S@f ≤ T@f)]
-    reveal_type(ConstraintSet.range(Never, S, T))
-    # revealed: ty_extensions.ConstraintSet[(S@f ≤ T@f)]
-    reveal_type(ConstraintSet.range(S, T, object))
+    # (S@f ≤ T@f)
+    c1 = ConstraintSet.range(Never, S, T)
+    c2 = ConstraintSet.range(S, T, object)
+    static_assert(c1 == c2)
 
 def f[T, S]():
-    # revealed: ty_extensions.ConstraintSet[(S@f ≤ T@f)]
-    reveal_type(ConstraintSet.range(Never, S, T))
-    # revealed: ty_extensions.ConstraintSet[(S@f ≤ T@f)]
-    reveal_type(ConstraintSet.range(S, T, object))
+    # (S@f ≤ T@f)
+    c1 = ConstraintSet.range(Never, S, T)
+    c2 = ConstraintSet.range(S, T, object)
+    static_assert(c1 == c2)
 ```
 
 Equivalence constraints are similar; internally we arbitrarily choose the "earlier" typevar to be
-the constraint, and the other the bound. But we display the result the same way no matter what.
+the constraint, and the other the bound.
 
 ```py
 def f[S, T]():
-    # revealed: ty_extensions.ConstraintSet[(S@f = T@f)]
-    reveal_type(ConstraintSet.range(T, S, T))
-    # revealed: ty_extensions.ConstraintSet[(S@f = T@f)]
-    reveal_type(ConstraintSet.range(S, T, S))
+    # (S@f = T@f)
+    c1 = ConstraintSet.range(T, S, T)
+    c2 = ConstraintSet.range(S, T, S)
+    static_assert(c1 == c2)
 
 def f[T, S]():
-    # revealed: ty_extensions.ConstraintSet[(S@f = T@f)]
-    reveal_type(ConstraintSet.range(T, S, T))
-    # revealed: ty_extensions.ConstraintSet[(S@f = T@f)]
-    reveal_type(ConstraintSet.range(S, T, S))
+    # (S@f = T@f)
+    c1 = ConstraintSet.range(T, S, T)
+    c2 = ConstraintSet.range(S, T, S)
+    static_assert(c1 == c2)
 ```
 
 But in the case of `S ≤ T ≤ U`, we end up with an ambiguity. Depending on the typevar ordering, that
-might display as `S ≤ T ≤ U`, or as `(S ≤ T) ∧ (T ≤ U)`.
+might represented internally as `S ≤ T ≤ U`, or as `(S ≤ T) ∧ (T ≤ U)`. However, this should not
+affect any uses of the constraint set.
 
 ```py
 def f[S, T, U]():
     # Could be either of:
-    #   ty_extensions.ConstraintSet[(S@f ≤ T@f ≤ U@f)]
-    #   ty_extensions.ConstraintSet[(S@f ≤ T@f) ∧ (T@f ≤ U@f)]
-    # reveal_type(ConstraintSet.range(S, T, U))
+    #   (S@f ≤ T@f ≤ U@f)
+    #   (S@f ≤ T@f) ∧ (T@f ≤ U@f)
+    ConstraintSet.range(S, T, U)
     ...
 ```
 
 ## Other simplifications
 
-### Displaying constraint sets
+### Ordering of intersection and union elements
 
-When displaying a constraint set, we transform the internal BDD representation into a DNF formula
-(i.e., the logical OR of several clauses, each of which is the logical AND of several constraints).
-This section contains several examples that show that we simplify the DNF formula as much as we can
-before displaying it.
-
-```py
-from ty_extensions import ConstraintSet
-
-def f[T, U]():
-    t1 = ConstraintSet.range(str, T, str)
-    t2 = ConstraintSet.range(bool, T, bool)
-    u1 = ConstraintSet.range(str, U, str)
-    u2 = ConstraintSet.range(bool, U, bool)
-
-    # revealed: ty_extensions.ConstraintSet[(T@f = bool) ∨ (T@f = str)]
-    reveal_type(t1 | t2)
-    # revealed: ty_extensions.ConstraintSet[(U@f = bool) ∨ (U@f = str)]
-    reveal_type(u1 | u2)
-    # revealed: ty_extensions.ConstraintSet[((T@f = bool) ∧ (U@f = bool)) ∨ ((T@f = bool) ∧ (U@f = str)) ∨ ((T@f = str) ∧ (U@f = bool)) ∨ ((T@f = str) ∧ (U@f = str))]
-    reveal_type((t1 | t2) & (u1 | u2))
-```
-
-We might simplify a BDD so much that we can no longer see the constraints that we used to construct
-it!
+The ordering of elements in a union or intersection do not affect what types satisfy a constraint
+set.
 
 ```py
 from typing import Never
-from ty_extensions import static_assert
+from ty_extensions import ConstraintSet, Intersection, static_assert
 
 def f[T]():
-    t_int = ConstraintSet.range(Never, T, int)
-    t_bool = ConstraintSet.range(Never, T, bool)
+    c1 = ConstraintSet.range(Never, T, str | int)
+    c2 = ConstraintSet.range(Never, T, int | str)
+    static_assert(c1 == c2)
 
-    # `T ≤ bool` implies `T ≤ int`: if a type satisfies the former, it must always satisfy the
-    # latter. We can turn that into a constraint set, using the equivalence `p → q == ¬p ∨ q`:
-    implication = ~t_bool | t_int
-    # revealed: ty_extensions.ConstraintSet[always]
-    reveal_type(implication)
-    static_assert(implication)
-
-    # However, because of that implication, some inputs aren't valid: it's not possible for
-    # `T ≤ bool` to be true and `T ≤ int` to be false. This is reflected in the constraint set's
-    # "domain", which maps valid inputs to `true` and invalid inputs to `false`. This means that two
-    # constraint sets that are both always satisfied will not be identical if they have different
-    # domains!
-    always = ConstraintSet.always()
-    # revealed: ty_extensions.ConstraintSet[always]
-    reveal_type(always)
-    static_assert(always)
-    static_assert(implication != always)
-```
-
-### Normalized bounds
-
-The lower and upper bounds of a constraint are normalized, so that we equate unions and
-intersections whose elements appear in different orders.
-
-```py
-from typing import Never
-from ty_extensions import ConstraintSet
-
-def f[T]():
-    # revealed: ty_extensions.ConstraintSet[(T@f ≤ int | str)]
-    reveal_type(ConstraintSet.range(Never, T, str | int))
-    # revealed: ty_extensions.ConstraintSet[(T@f ≤ int | str)]
-    reveal_type(ConstraintSet.range(Never, T, int | str))
+    c1 = ConstraintSet.range(Never, T, Intersection[str, int])
+    c2 = ConstraintSet.range(Never, T, Intersection[int, str])
+    static_assert(c1 == c2)
 ```
 
 ### Constraints on the same typevar
@@ -846,15 +791,20 @@ static types.)
 
 ```py
 from typing import Never
-from ty_extensions import ConstraintSet
+from ty_extensions import ConstraintSet, static_assert
 
 def same_typevar[T]():
-    # revealed: ty_extensions.ConstraintSet[(T@same_typevar = *)]
-    reveal_type(ConstraintSet.range(Never, T, T))
-    # revealed: ty_extensions.ConstraintSet[(T@same_typevar = *)]
-    reveal_type(ConstraintSet.range(T, T, object))
-    # revealed: ty_extensions.ConstraintSet[(T@same_typevar = *)]
-    reveal_type(ConstraintSet.range(T, T, T))
+    constraints = ConstraintSet.range(Never, T, T)
+    expected = ConstraintSet.range(Never, T, object)
+    static_assert(constraints == expected)
+
+    constraints = ConstraintSet.range(T, T, object)
+    expected = ConstraintSet.range(Never, T, object)
+    static_assert(constraints == expected)
+
+    constraints = ConstraintSet.range(T, T, T)
+    expected = ConstraintSet.range(Never, T, object)
+    static_assert(constraints == expected)
 ```
 
 This is also true when the typevar appears in a union in the upper bound, or in an intersection in
@@ -865,12 +815,17 @@ as shown above.)
 from ty_extensions import Intersection
 
 def same_typevar[T]():
-    # revealed: ty_extensions.ConstraintSet[(T@same_typevar = *)]
-    reveal_type(ConstraintSet.range(Never, T, T | None))
-    # revealed: ty_extensions.ConstraintSet[(T@same_typevar = *)]
-    reveal_type(ConstraintSet.range(Intersection[T, None], T, object))
-    # revealed: ty_extensions.ConstraintSet[(T@same_typevar = *)]
-    reveal_type(ConstraintSet.range(Intersection[T, None], T, T | None))
+    constraints = ConstraintSet.range(Never, T, T | None)
+    expected = ConstraintSet.range(Never, T, object)
+    static_assert(constraints == expected)
+
+    constraints = ConstraintSet.range(Intersection[T, None], T, object)
+    expected = ConstraintSet.range(Never, T, object)
+    static_assert(constraints == expected)
+
+    constraints = ConstraintSet.range(Intersection[T, None], T, T | None)
+    expected = ConstraintSet.range(Never, T, object)
+    static_assert(constraints == expected)
 ```
 
 Similarly, if the lower bound is an intersection containing the _negation_ of the typevar, then the
@@ -880,8 +835,11 @@ constraint set can never be satisfied, since every type is disjoint with its neg
 from ty_extensions import Not
 
 def same_typevar[T]():
-    # revealed: ty_extensions.ConstraintSet[(T@same_typevar ≠ *)]
-    reveal_type(ConstraintSet.range(Intersection[Not[T], None], T, object))
-    # revealed: ty_extensions.ConstraintSet[(T@same_typevar ≠ *)]
-    reveal_type(ConstraintSet.range(Not[T], T, object))
+    constraints = ConstraintSet.range(Intersection[Not[T], None], T, object)
+    expected = ~ConstraintSet.range(Never, T, object)
+    static_assert(constraints == expected)
+
+    constraints = ConstraintSet.range(Not[T], T, object)
+    expected = ~ConstraintSet.range(Never, T, object)
+    static_assert(constraints == expected)
 ```

crates/ty_python_semantic/resources/mdtest/type_properties/implies_subtype_of.md

@@ -50,27 +50,37 @@ question when considering a typevar, by translating the desired relationship int
 
 ```py
 from typing import Any
-from ty_extensions import is_assignable_to, is_subtype_of
+from ty_extensions import ConstraintSet, is_assignable_to, is_subtype_of, static_assert
 
 def assignability[T]():
-    # TODO: revealed: ty_extensions.ConstraintSet[T@assignability ≤ bool]
-    # revealed: ty_extensions.ConstraintSet[never]
-    reveal_type(is_assignable_to(T, bool))
-    # TODO: revealed: ty_extensions.ConstraintSet[T@assignability ≤ int]
-    # revealed: ty_extensions.ConstraintSet[never]
-    reveal_type(is_assignable_to(T, int))
-    # revealed: ty_extensions.ConstraintSet[always]
-    reveal_type(is_assignable_to(T, object))
+    constraints = is_assignable_to(T, bool)
+    # TODO: expected = ConstraintSet.range(Never, T, bool)
+    expected = ConstraintSet.never()
+    static_assert(constraints == expected)
+
+    constraints = is_assignable_to(T, int)
+    # TODO: expected = ConstraintSet.range(Never, T, int)
+    expected = ConstraintSet.never()
+    static_assert(constraints == expected)
+
+    constraints = is_assignable_to(T, object)
+    expected = ConstraintSet.always()
+    static_assert(constraints == expected)
 
 def subtyping[T]():
-    # TODO: revealed: ty_extensions.ConstraintSet[T@subtyping ≤ bool]
-    # revealed: ty_extensions.ConstraintSet[never]
-    reveal_type(is_subtype_of(T, bool))
-    # TODO: revealed: ty_extensions.ConstraintSet[T@subtyping ≤ int]
-    # revealed: ty_extensions.ConstraintSet[never]
-    reveal_type(is_subtype_of(T, int))
-    # revealed: ty_extensions.ConstraintSet[always]
-    reveal_type(is_subtype_of(T, object))
+    constraints = is_subtype_of(T, bool)
+    # TODO: expected = ConstraintSet.range(Never, T, bool)
+    expected = ConstraintSet.never()
+    static_assert(constraints == expected)
+
+    constraints = is_subtype_of(T, int)
+    # TODO: expected = ConstraintSet.range(Never, T, int)
+    expected = ConstraintSet.never()
+    static_assert(constraints == expected)
+
+    constraints = is_subtype_of(T, object)
+    expected = ConstraintSet.always()
+    static_assert(constraints == expected)
 ```
 
 When checking assignability with a dynamic type, we use the bottom and top materializations of the
@@ -88,50 +98,64 @@ class Contravariant[T]:
         pass
 
 def assignability[T]():
-    # aka [T@assignability ≤ object], which is always satisfiable
-    # revealed: ty_extensions.ConstraintSet[always]
-    reveal_type(is_assignable_to(T, Any))
+    constraints = is_assignable_to(T, Any)
+    expected = ConstraintSet.range(Never, T, object)
+    static_assert(constraints == expected)
 
-    # aka [Never ≤ T@assignability], which is always satisfiable
-    # revealed: ty_extensions.ConstraintSet[always]
-    reveal_type(is_assignable_to(Any, T))
+    constraints = is_assignable_to(Any, T)
+    expected = ConstraintSet.range(Never, T, object)
+    static_assert(constraints == expected)
 
-    # TODO: revealed: ty_extensions.ConstraintSet[T@assignability ≤ Covariant[object]]
-    # revealed: ty_extensions.ConstraintSet[never]
-    reveal_type(is_assignable_to(T, Covariant[Any]))
-    # TODO: revealed: ty_extensions.ConstraintSet[Covariant[Never] ≤ T@assignability]
-    # revealed: ty_extensions.ConstraintSet[never]
-    reveal_type(is_assignable_to(Covariant[Any], T))
+    constraints = is_assignable_to(T, Covariant[Any])
+    # TODO: expected = ConstraintSet.range(Never, T, Covariant[object])
+    expected = ConstraintSet.never()
+    static_assert(constraints == expected)
 
-    # TODO: revealed: ty_extensions.ConstraintSet[T@assignability ≤ Contravariant[Never]]
-    # revealed: ty_extensions.ConstraintSet[never]
-    reveal_type(is_assignable_to(T, Contravariant[Any]))
-    # TODO: revealed: ty_extensions.ConstraintSet[Contravariant[object] ≤ T@assignability]
-    # revealed: ty_extensions.ConstraintSet[never]
-    reveal_type(is_assignable_to(Contravariant[Any], T))
+    constraints = is_assignable_to(Covariant[Any], T)
+    # TODO: expected = ConstraintSet.range(Covariant[Never], T, object)
+    expected = ConstraintSet.never()
+    static_assert(constraints == expected)
+
+    constraints = is_assignable_to(T, Contravariant[Any])
+    # TODO: expected = ConstraintSet.range(Never, T, Contravariant[Never])
+    expected = ConstraintSet.never()
+    static_assert(constraints == expected)
+
+    constraints = is_assignable_to(Contravariant[Any], T)
+    # TODO: expected = ConstraintSet.range(Contravariant[object], T, object)
+    expected = ConstraintSet.never()
+    static_assert(constraints == expected)
 
 def subtyping[T]():
-    # aka [T@assignability ≤ object], which is always satisfiable
-    # revealed: ty_extensions.ConstraintSet[never]
-    reveal_type(is_subtype_of(T, Any))
+    constraints = is_subtype_of(T, Any)
+    # TODO: expected = ConstraintSet.range(Never, T, Never)
+    expected = ConstraintSet.never()
+    static_assert(constraints == expected)
 
-    # aka [Never ≤ T@assignability], which is always satisfiable
-    # revealed: ty_extensions.ConstraintSet[never]
-    reveal_type(is_subtype_of(Any, T))
+    constraints = is_subtype_of(Any, T)
+    # TODO: expected = ConstraintSet.range(object, T, object)
+    expected = ConstraintSet.never()
+    static_assert(constraints == expected)
 
-    # TODO: revealed: ty_extensions.ConstraintSet[T@subtyping ≤ Covariant[Never]]
-    # revealed: ty_extensions.ConstraintSet[never]
-    reveal_type(is_subtype_of(T, Covariant[Any]))
-    # TODO: revealed: ty_extensions.ConstraintSet[Covariant[object] ≤ T@subtyping]
-    # revealed: ty_extensions.ConstraintSet[never]
-    reveal_type(is_subtype_of(Covariant[Any], T))
+    constraints = is_subtype_of(T, Covariant[Any])
+    # TODO: expected = ConstraintSet.range(Never, T, Covariant[Never])
+    expected = ConstraintSet.never()
+    static_assert(constraints == expected)
 
-    # TODO: revealed: ty_extensions.ConstraintSet[T@subtyping ≤ Contravariant[object]]
-    # revealed: ty_extensions.ConstraintSet[never]
-    reveal_type(is_subtype_of(T, Contravariant[Any]))
-    # TODO: revealed: ty_extensions.ConstraintSet[Contravariant[Never] ≤ T@subtyping]
-    # revealed: ty_extensions.ConstraintSet[never]
-    reveal_type(is_subtype_of(Contravariant[Any], T))
+    constraints = is_subtype_of(Covariant[Any], T)
+    # TODO: expected = ConstraintSet.range(Covariant[object], T, object)
+    expected = ConstraintSet.never()
+    static_assert(constraints == expected)
+
+    constraints = is_subtype_of(T, Contravariant[Any])
+    # TODO: expected = ConstraintSet.range(Never, T, Contravariant[object])
+    expected = ConstraintSet.never()
+    static_assert(constraints == expected)
+
+    constraints = is_subtype_of(Contravariant[Any], T)
+    # TODO: expected = ConstraintSet.range(Contravariant[Never], T, object)
+    expected = ConstraintSet.never()
+    static_assert(constraints == expected)
 ```
 
 At some point, though, we need to resolve a constraint set; at that point, we can no longer punt on

crates/ty_python_semantic/resources/primer/good.txt

@@ -14,6 +14,7 @@ altair
 antidote
 anyio
 apprise
+archinstall
 artigraph
 arviz
 async-utils
@@ -25,7 +26,9 @@ bidict
 black
 bokeh
 boostedblob
+build
 check-jsonschema
+cibuildwheel
 cki-lib
 cloud-init
 colour
@@ -104,6 +107,7 @@ pylox
 pyodide
 pyp
 pyppeteer
+pyproject-metadata
 pytest
 pytest-robotframework
 python-chess
@@ -118,6 +122,7 @@ schemathesis
 scikit-build-core
 scikit-learn
 scipy
+scipy-stubs
 scrapy
 setuptools
 sockeye

crates/ty_python_semantic/src/lib.rs

@@ -13,7 +13,8 @@ pub use diagnostic::add_inferred_python_version_hint_to_diagnostic;
 pub use module_name::{ModuleName, ModuleNameResolutionError};
 pub use module_resolver::{
     KnownModule, Module, SearchPath, SearchPathValidationError, SearchPaths, all_modules,
-    list_modules, resolve_module, resolve_real_module, system_module_search_paths,
+    list_modules, resolve_module, resolve_real_module, resolve_real_shadowable_module,
+    system_module_search_paths,
 };
 pub use program::{
     Program, ProgramSettings, PythonVersionFileSource, PythonVersionSource,
@@ -25,6 +26,7 @@ pub use semantic_model::{
     Completion, HasDefinition, HasType, MemberDefinition, NameKind, SemanticModel,
 };
 pub use site_packages::{PythonEnvironment, SitePackagesPaths, SysPrefixPathOrigin};
+pub use suppression::create_suppression_fix;
 pub use types::DisplaySettings;
 pub use types::ide_support::{
     ImportAliasResolution, ResolvedDefinition, definitions_for_attribute, definitions_for_bin_op,

crates/ty_python_semantic/src/module_resolver/list.rs

@@ -8,9 +8,7 @@ use crate::program::Program;
 
 use super::module::{Module, ModuleKind};
 use super::path::{ModulePath, SearchPath, SystemOrVendoredPathRef};
-use super::resolver::{
-    ModuleResolveMode, ResolverContext, is_non_shadowable, resolve_file_module, search_paths,
-};
+use super::resolver::{ModuleResolveMode, ResolverContext, resolve_file_module, search_paths};
 
 /// List all available modules, including all sub-modules, sorted in lexicographic order.
 pub fn all_modules(db: &dyn Db) -> Vec<Module<'_>> {
@@ -309,7 +307,8 @@ impl<'db> Lister<'db> {
 
     /// Returns true if the given module name cannot be shadowable.
     fn is_non_shadowable(&self, name: &ModuleName) -> bool {
-        is_non_shadowable(self.python_version().minor, name.as_str())
+        ModuleResolveMode::StubsAllowed
+            .is_non_shadowable(self.python_version().minor, name.as_str())
     }
 
     /// Returns the Python version we want to perform module resolution

crates/ty_python_semantic/src/module_resolver/mod.rs

@@ -6,7 +6,7 @@ pub use module::Module;
 pub use path::{SearchPath, SearchPathValidationError};
 pub use resolver::SearchPaths;
 pub(crate) use resolver::file_to_module;
-pub use resolver::{resolve_module, resolve_real_module};
+pub use resolver::{resolve_module, resolve_real_module, resolve_real_shadowable_module};
 use ruff_db::system::SystemPath;
 
 use crate::Db;

crates/ty_python_semantic/src/module_resolver/resolver.rs

@@ -47,8 +47,33 @@ pub fn resolve_real_module<'db>(db: &'db dyn Db, module_name: &ModuleName) -> Op
     resolve_module_query(db, interned_name)
 }
 
+/// Resolves a module name to a module (stubs not allowed, some shadowing is
+/// allowed).
+///
+/// In particular, this allows `typing_extensions` to be shadowed by a
+/// non-standard library module. This is useful in the context of the LSP
+/// where we don't want to pretend as if these modules are always available at
+/// runtime.
+///
+/// This should generally only be used within the context of the LSP. Using it
+/// within ty proper risks being unable to resolve builtin modules since they
+/// are involved in an import cycle with `builtins`.
+pub fn resolve_real_shadowable_module<'db>(
+    db: &'db dyn Db,
+    module_name: &ModuleName,
+) -> Option<Module<'db>> {
+    let interned_name = ModuleNameIngredient::new(
+        db,
+        module_name,
+        ModuleResolveMode::StubsNotAllowedSomeShadowingAllowed,
+    );
+
+    resolve_module_query(db, interned_name)
+}
+
 /// Which files should be visible when doing a module query
 #[derive(Debug, Copy, Clone, PartialEq, Eq, PartialOrd, Ord, Hash, get_size2::GetSize)]
+#[allow(clippy::enum_variant_names)]
 pub(crate) enum ModuleResolveMode {
     /// Stubs are allowed to appear.
     ///
@@ -61,6 +86,13 @@ pub(crate) enum ModuleResolveMode {
     /// implementations. When querying searchpaths this also notably replaces typeshed with
     /// the "real" stdlib.
     StubsNotAllowed,
+    /// Like `StubsNotAllowed`, but permits some modules to be shadowed.
+    ///
+    /// In particular, this allows `typing_extensions` to be shadowed by a
+    /// non-standard library module. This is useful in the context of the LSP
+    /// where we don't want to pretend as if these modules are always available
+    /// at runtime.
+    StubsNotAllowedSomeShadowingAllowed,
 }
 
 #[salsa::interned(heap_size=ruff_memory_usage::heap_size)]
@@ -73,6 +105,39 @@ impl ModuleResolveMode {
     fn stubs_allowed(self) -> bool {
         matches!(self, Self::StubsAllowed)
     }
+
+    /// Returns `true` if the module name refers to a standard library module
+    /// which can't be shadowed by a first-party module.
+    ///
+    /// This includes "builtin" modules, which can never be shadowed at runtime
+    /// either. Additionally, certain other modules that are involved in an
+    /// import cycle with `builtins` (`types`, `typing_extensions`, etc.) are
+    /// also considered non-shadowable, unless the module resolution mode
+    /// specifically opts into allowing some of them to be shadowed. This
+    /// latter set of modules cannot be allowed to be shadowed by first-party
+    /// or "extra-path" modules in ty proper, or we risk panics in unexpected
+    /// places due to being unable to resolve builtin symbols. This is similar
+    /// behaviour to other type checkers such as mypy:
+    /// <https://github.com/python/mypy/blob/3807423e9d98e678bf16b13ec8b4f909fe181908/mypy/build.py#L104-L117>
+    pub(super) fn is_non_shadowable(self, minor_version: u8, module_name: &str) -> bool {
+        // Builtin modules are never shadowable, no matter what.
+        if ruff_python_stdlib::sys::is_builtin_module(minor_version, module_name) {
+            return true;
+        }
+        // Similarly for `types`, which is always available at runtime.
+        if module_name == "types" {
+            return true;
+        }
+
+        // Otherwise, some modules should only be conditionally allowed
+        // to be shadowed, depending on the module resolution mode.
+        match self {
+            ModuleResolveMode::StubsAllowed | ModuleResolveMode::StubsNotAllowed => {
+                module_name == "typing_extensions"
+            }
+            ModuleResolveMode::StubsNotAllowedSomeShadowingAllowed => false,
+        }
+    }
 }
 
 /// Salsa query that resolves an interned [`ModuleNameIngredient`] to a module.
@@ -386,7 +451,10 @@ impl SearchPaths {
     pub(crate) fn stdlib(&self, mode: ModuleResolveMode) -> Option<&SearchPath> {
         match mode {
             ModuleResolveMode::StubsAllowed => self.stdlib_path.as_ref(),
-            ModuleResolveMode::StubsNotAllowed => self.real_stdlib_path.as_ref(),
+            ModuleResolveMode::StubsNotAllowed
+            | ModuleResolveMode::StubsNotAllowedSomeShadowingAllowed => {
+                self.real_stdlib_path.as_ref()
+            }
         }
     }
 
@@ -439,7 +507,8 @@ pub(crate) fn dynamic_resolution_paths<'db>(
     // Use the `ModuleResolveMode` to determine which stdlib (if any) to mark as existing
     let stdlib = match mode.mode(db) {
         ModuleResolveMode::StubsAllowed => stdlib_path,
-        ModuleResolveMode::StubsNotAllowed => real_stdlib_path,
+        ModuleResolveMode::StubsNotAllowed
+        | ModuleResolveMode::StubsNotAllowedSomeShadowingAllowed => real_stdlib_path,
     };
     if let Some(path) = stdlib.as_ref().and_then(SearchPath::as_system_path) {
         existing_paths.insert(Cow::Borrowed(path));
@@ -684,27 +753,13 @@ struct ModuleNameIngredient<'db> {
     pub(super) mode: ModuleResolveMode,
 }
 
-/// Returns `true` if the module name refers to a standard library module which can't be shadowed
-/// by a first-party module.
-///
-/// This includes "builtin" modules, which can never be shadowed at runtime either, as well as
-/// certain other modules that are involved in an import cycle with `builtins` (`types`,
-/// `typing_extensions`, etc.). This latter set of modules cannot be allowed to be shadowed by
-/// first-party or "extra-path" modules, or we risk panics in unexpected places due to being
-/// unable to resolve builtin symbols. This is similar behaviour to other type checkers such
-/// as mypy: <https://github.com/python/mypy/blob/3807423e9d98e678bf16b13ec8b4f909fe181908/mypy/build.py#L104-L117>
-pub(super) fn is_non_shadowable(minor_version: u8, module_name: &str) -> bool {
-    matches!(module_name, "types" | "typing_extensions")
-        || ruff_python_stdlib::sys::is_builtin_module(minor_version, module_name)
-}
-
 /// Given a module name and a list of search paths in which to lookup modules,
 /// attempt to resolve the module name
 fn resolve_name(db: &dyn Db, name: &ModuleName, mode: ModuleResolveMode) -> Option<ResolvedName> {
     let program = Program::get(db);
     let python_version = program.python_version(db);
     let resolver_state = ResolverContext::new(db, python_version, mode);
-    let is_non_shadowable = is_non_shadowable(python_version.minor, name.as_str());
+    let is_non_shadowable = mode.is_non_shadowable(python_version.minor, name.as_str());
 
     let name = RelaxedModuleName::new(name);
     let stub_name = name.to_stub_package();

crates/ty_python_semantic/src/semantic_index/builder.rs

@@ -1478,6 +1478,8 @@ impl<'ast> Visitor<'ast> for SemanticIndexBuilder<'_, 'ast> {
                     }
 
                     let (symbol_name, is_reexported) = if let Some(asname) = &alias.asname {
+                        self.scopes_by_expression
+                            .record_expression(asname, self.current_scope());
                         (asname.id.clone(), asname.id == alias.name.id)
                     } else {
                         (Name::new(alias.name.id.split('.').next().unwrap()), false)
@@ -1651,6 +1653,8 @@ impl<'ast> Visitor<'ast> for SemanticIndexBuilder<'_, 'ast> {
                     }
 
                     let (symbol_name, is_reexported) = if let Some(asname) = &alias.asname {
+                        self.scopes_by_expression
+                            .record_expression(asname, self.current_scope());
                         // It's re-exported if it's `from ... import x as x`
                         (&asname.id, asname.id == alias.name.id)
                     } else {

crates/ty_python_semantic/src/semantic_index/reachability_constraints.rs

@@ -336,6 +336,7 @@ fn pattern_kind_to_type<'db>(db: &'db dyn Db, kind: &PatternPredicateKind<'db>)
                 infer_expression_type(db, *class_expr, TypeContext::default())
                     .to_instance(db)
                     .unwrap_or(Type::Never)
+                    .top_materialization(db)
             } else {
                 Type::Never
             }

crates/ty_python_semantic/src/semantic_model.rs

@@ -1,19 +1,19 @@
 use ruff_db::files::{File, FilePath};
 use ruff_db::source::{line_index, source_text};
-use ruff_python_ast::{self as ast, ExprStringLiteral, ModExpression};
+use ruff_python_ast::{self as ast, ExprStringLiteral, Identifier, ModExpression};
 use ruff_python_ast::{Expr, ExprRef, HasNodeIndex, name::Name};
 use ruff_python_parser::Parsed;
 use ruff_source_file::LineIndex;
 use rustc_hash::FxHashMap;
 
-use crate::Db;
 use crate::module_name::ModuleName;
 use crate::module_resolver::{KnownModule, Module, list_modules, resolve_module};
 use crate::semantic_index::definition::Definition;
 use crate::semantic_index::scope::FileScopeId;
 use crate::semantic_index::semantic_index;
-use crate::types::ide_support::{Member, all_declarations_and_bindings, all_members};
+use crate::types::list_members::{Member, all_members, all_members_of_scope};
 use crate::types::{Type, binding_type, infer_scope_types};
+use crate::{Db, resolve_real_shadowable_module};
 
 /// The primary interface the LSP should use for querying semantic information about a [`File`].
 ///
@@ -76,7 +76,7 @@ impl<'db> SemanticModel<'db> {
 
         for (file_scope, _) in index.ancestor_scopes(file_scope) {
             for memberdef in
-                all_declarations_and_bindings(self.db, file_scope.to_scope_id(self.db, self.file))
+                all_members_of_scope(self.db, file_scope.to_scope_id(self.db, self.file))
             {
                 members.insert(
                     memberdef.member.name,
@@ -90,6 +90,19 @@ impl<'db> SemanticModel<'db> {
         members
     }
 
+    pub fn inferred_type_for_identifier(&self, identifier: &Identifier) -> Type<'db> {
+        // TODO(#1637): semantic tokens is making this crash even with
+        // `try_expr_ref_in_ast` guarding this, for now just use `try_expression_scope_id`.
+        // The problematic input is `x: "float` (with a dangling quote). I imagine the issue
+        // is we're too eagerly setting `is_string_annotation` in inference.
+        let Some(file_scope) = self.scope(identifier.into()) else {
+            return Type::unknown();
+        };
+        let scope = file_scope.to_scope_id(self.db, self.file);
+
+        infer_scope_types(self.db, scope).expression_type(identifier)
+    }
+
     /// Resolve the given import made in this file to a Type
     pub fn resolve_module_type(&self, module: Option<&str>, level: u32) -> Option<Type<'db>> {
         let module = self.resolve_module(module, level)?;
@@ -105,8 +118,14 @@ impl<'db> SemanticModel<'db> {
 
     /// Returns completions for symbols available in a `import <CURSOR>` context.
     pub fn import_completions(&self) -> Vec<Completion<'db>> {
+        let typing_extensions = ModuleName::new("typing_extensions").unwrap();
+        let is_typing_extensions_available = self.file.is_stub(self.db)
+            || resolve_real_shadowable_module(self.db, &typing_extensions).is_some();
         list_modules(self.db)
             .into_iter()
+            .filter(|module| {
+                is_typing_extensions_available || module.name(self.db) != &typing_extensions
+            })
             .map(|module| {
                 let builtin = module.is_known(self.db, KnownModule::Builtins);
                 let ty = Type::module_literal(self.db, self.file, module);
@@ -215,12 +234,13 @@ impl<'db> SemanticModel<'db> {
         let mut completions = vec![];
         for (file_scope, _) in index.ancestor_scopes(file_scope) {
             completions.extend(
-                all_declarations_and_bindings(self.db, file_scope.to_scope_id(self.db, self.file))
-                    .map(|memberdef| Completion {
+                all_members_of_scope(self.db, file_scope.to_scope_id(self.db, self.file)).map(
+                    |memberdef| Completion {
                         name: memberdef.member.name,
                         ty: Some(memberdef.member.ty),
                         builtin: false,
-                    }),
+                    },
+                ),
             );
         }
         // Builtins are available in all scopes.
@@ -397,7 +417,7 @@ pub trait HasType {
 }
 
 pub trait HasDefinition {
-    /// Returns the inferred type of `self`.
+    /// Returns the definition of `self`.
     ///
     /// ## Panics
     /// May panic if `self` is from another file than `model`.

crates/ty_python_semantic/src/suppression.rs

@@ -375,6 +375,77 @@ fn check_unused_suppressions(context: &mut CheckSuppressionsContext) {
     }
 }
 
+/// Creates a fix for adding a suppression comment to suppress `lint` for `range`.
+///
+/// The fix prefers adding the code to an existing `ty: ignore[]` comment over
+/// adding a new suppression comment.
+pub fn create_suppression_fix(db: &dyn Db, file: File, id: LintId, range: TextRange) -> Fix {
+    let suppressions = suppressions(db, file);
+    let source = source_text(db, file);
+
+    let mut existing_suppressions = suppressions.line_suppressions(range).filter(|suppression| {
+        matches!(
+            suppression.target,
+            SuppressionTarget::Lint(_) | SuppressionTarget::Empty,
+        )
+    });
+
+    // If there's an existing `ty: ignore[]` comment, append the code to it instead of creating a new suppression comment.
+    if let Some(existing) = existing_suppressions.next() {
+        let comment_text = &source[existing.comment_range];
+        // Only add to the existing ignore comment if it has no reason.
+        if let Some(before_closing_paren) = comment_text.trim_end().strip_suffix(']') {
+            let up_to_last_code = before_closing_paren.trim_end();
+
+            let insertion = if up_to_last_code.ends_with(',') {
+                format!(" {id}", id = id.name())
+            } else {
+                format!(", {id}", id = id.name())
+            };
+
+            let relative_offset_from_end = comment_text.text_len() - up_to_last_code.text_len();
+
+            return Fix::safe_edit(Edit::insertion(
+                insertion,
+                existing.comment_range.end() - relative_offset_from_end,
+            ));
+        }
+    }
+
+    // Always insert a new suppression at the end of the range to avoid having to deal with multiline strings
+    // etc.
+    let parsed = parsed_module(db, file).load(db);
+    let tokens_after = parsed.tokens().after(range.end());
+
+    // Same as for `line_end` when building up the `suppressions`: Ignore newlines
+    // in multiline-strings, inside f-strings, or after a line continuation because we can't
+    // place a comment on those lines.
+    let line_end = tokens_after
+        .iter()
+        .find(|token| {
+            matches!(
+                token.kind(),
+                TokenKind::Newline | TokenKind::NonLogicalNewline
+            )
+        })
+        .map(Ranged::start)
+        .unwrap_or(source.text_len());
+
+    let up_to_line_end = &source[..line_end.to_usize()];
+    let up_to_first_content = up_to_line_end.trim_end();
+    let trailing_whitespace_len = up_to_line_end.text_len() - up_to_first_content.text_len();
+
+    let insertion = format!("  # ty:ignore[{id}]", id = id.name());
+
+    Fix::safe_edit(if trailing_whitespace_len == TextSize::ZERO {
+        Edit::insertion(insertion, line_end)
+    } else {
+        // `expr # fmt: off<trailing_whitespace>`
+        // Trim the trailing whitespace
+        Edit::replacement(insertion, line_end - trailing_whitespace_len, line_end)
+    })
+}
+
 struct CheckSuppressionsContext<'a> {
     db: &'a dyn Db,
     file: File,

crates/ty_python_semantic/src/types.rs

@@ -96,11 +96,12 @@ mod generics;
 pub mod ide_support;
 mod infer;
 mod instance;
-mod liskov;
+pub mod list_members;
 mod member;
 mod mro;
 mod narrow;
 mod newtype;
+mod overrides;
 mod protocol_class;
 mod signatures;
 mod special_form;
@@ -573,20 +574,19 @@ impl<'db> PropertyInstanceType<'db> {
         db: &'db dyn Db,
         div: Type<'db>,
         nested: bool,
-        visitor: &NormalizedVisitor<'db>,
     ) -> Option<Self> {
         let getter = match self.getter(db) {
-            Some(ty) if nested => Some(ty.recursive_type_normalized_impl(db, div, true, visitor)?),
+            Some(ty) if nested => Some(ty.recursive_type_normalized_impl(db, div, true)?),
             Some(ty) => Some(
-                ty.recursive_type_normalized_impl(db, div, true, visitor)
+                ty.recursive_type_normalized_impl(db, div, true)
                     .unwrap_or(div),
             ),
             None => None,
         };
         let setter = match self.setter(db) {
-            Some(ty) if nested => Some(ty.recursive_type_normalized_impl(db, div, true, visitor)?),
+            Some(ty) if nested => Some(ty.recursive_type_normalized_impl(db, div, true)?),
             Some(ty) => Some(
-                ty.recursive_type_normalized_impl(db, div, true, visitor)
+                ty.recursive_type_normalized_impl(db, div, true)
                     .unwrap_or(div),
             ),
             None => None,
@@ -957,8 +957,13 @@ impl<'db> Type<'db> {
         self.is_instance_of(db, KnownClass::NotImplementedType)
     }
 
-    pub(crate) const fn is_todo(&self) -> bool {
-        matches!(self, Type::Dynamic(DynamicType::Todo(_)))
+    pub(crate) fn is_todo(&self) -> bool {
+        self.as_dynamic().is_some_and(|dynamic| match dynamic {
+            DynamicType::Any | DynamicType::Unknown | DynamicType::Divergent(_) => false,
+            DynamicType::Todo(_) | DynamicType::TodoStarredExpression | DynamicType::TodoUnpack => {
+                true
+            }
+        })
     }
 
     pub const fn is_generic_alias(&self) -> bool {
@@ -1553,15 +1558,14 @@ impl<'db> Type<'db> {
     #[must_use]
     pub(crate) fn recursive_type_normalized(self, db: &'db dyn Db, cycle: &salsa::Cycle) -> Self {
         cycle.head_ids().fold(self, |ty, id| {
-            let visitor = NormalizedVisitor::new(Type::divergent(id));
-            ty.recursive_type_normalized_impl(db, Type::divergent(id), false, &visitor)
+            ty.recursive_type_normalized_impl(db, Type::divergent(id), false)
                 .unwrap_or(Type::divergent(id))
         })
     }
 
     /// Normalizes types including divergent types (recursive types), which is necessary for convergence of fixed-point iteration.
-    /// When nested is true, propagate `None`. That is, if the type contains a `Divergent` type, the return value of this method is `None`.
-    /// When nested is false, create a type containing `Divergent` types instead of propagating `None`.
+    /// When `nested` is true, propagate `None`. That is, if the type contains a `Divergent` type, the return value of this method is `None` (so we can use the `?` operator).
+    /// When `nested` is false, create a type containing `Divergent` types instead of propagating `None` (we should use `unwrap_or(Divergent)`).
     /// This is to preserve the structure of the non-divergent parts of the type instead of completely collapsing the type containing a `Divergent` type into a `Divergent` type.
     /// ```python
     /// tuple[tuple[Divergent, Literal[1]], Literal[1]].recursive_type_normalized(nested: false)
@@ -1580,102 +1584,73 @@ impl<'db> Type<'db> {
         db: &'db dyn Db,
         div: Type<'db>,
         nested: bool,
-        visitor: &NormalizedVisitor<'db>,
     ) -> Option<Self> {
         if nested && self == div {
             return None;
         }
         match self {
-            Type::Union(union) => visitor.try_visit(self, || {
-                union.recursive_type_normalized_impl(db, div, nested, visitor)
-            }),
-            Type::Intersection(intersection) => visitor.try_visit(self, || {
-                intersection
-                    .recursive_type_normalized_impl(db, div, nested, visitor)
-                    .map(Type::Intersection)
-            }),
-            Type::Callable(callable) => visitor.try_visit(self, || {
-                callable
-                    .recursive_type_normalized_impl(db, div, nested, visitor)
-                    .map(Type::Callable)
-            }),
-            Type::ProtocolInstance(protocol) => visitor.try_visit(self, || {
-                protocol
-                    .recursive_type_normalized_impl(db, div, nested, visitor)
-                    .map(Type::ProtocolInstance)
-            }),
-            Type::NominalInstance(instance) => visitor.try_visit(self, || {
-                instance
-                    .recursive_type_normalized_impl(db, div, nested, visitor)
-                    .map(Type::NominalInstance)
-            }),
-            Type::FunctionLiteral(function) => visitor.try_visit(self, || {
-                function
-                    .recursive_type_normalized_impl(db, div, nested, visitor)
-                    .map(Type::FunctionLiteral)
-            }),
-            Type::PropertyInstance(property) => visitor.try_visit(self, || {
-                property
-                    .recursive_type_normalized_impl(db, div, nested, visitor)
-                    .map(Type::PropertyInstance)
-            }),
-            Type::KnownBoundMethod(method_kind) => visitor.try_visit(self, || {
-                method_kind
-                    .recursive_type_normalized_impl(db, div, nested, visitor)
-                    .map(Type::KnownBoundMethod)
-            }),
-            Type::BoundMethod(method) => visitor.try_visit(self, || {
-                method
-                    .recursive_type_normalized_impl(db, div, nested, visitor)
-                    .map(Type::BoundMethod)
-            }),
-            Type::BoundSuper(bound_super) => visitor.try_visit(self, || {
-                bound_super
-                    .recursive_type_normalized_impl(db, div, nested, visitor)
-                    .map(Type::BoundSuper)
-            }),
-            Type::GenericAlias(generic) => visitor.try_visit(self, || {
-                generic
-                    .recursive_type_normalized_impl(db, div, nested, visitor)
-                    .map(Type::GenericAlias)
-            }),
-            Type::SubclassOf(subclass_of) => visitor.try_visit(self, || {
-                subclass_of
-                    .recursive_type_normalized_impl(db, div, nested, visitor)
-                    .map(Type::SubclassOf)
-            }),
+            Type::Union(union) => union.recursive_type_normalized_impl(db, div, nested),
+            Type::Intersection(intersection) => intersection
+                .recursive_type_normalized_impl(db, div, nested)
+                .map(Type::Intersection),
+            Type::Callable(callable) => callable
+                .recursive_type_normalized_impl(db, div, nested)
+                .map(Type::Callable),
+            Type::ProtocolInstance(protocol) => protocol
+                .recursive_type_normalized_impl(db, div, nested)
+                .map(Type::ProtocolInstance),
+            Type::NominalInstance(instance) => instance
+                .recursive_type_normalized_impl(db, div, nested)
+                .map(Type::NominalInstance),
+            Type::FunctionLiteral(function) => function
+                .recursive_type_normalized_impl(db, div, nested)
+                .map(Type::FunctionLiteral),
+            Type::PropertyInstance(property) => property
+                .recursive_type_normalized_impl(db, div, nested)
+                .map(Type::PropertyInstance),
+            Type::KnownBoundMethod(method_kind) => method_kind
+                .recursive_type_normalized_impl(db, div, nested)
+                .map(Type::KnownBoundMethod),
+            Type::BoundMethod(method) => method
+                .recursive_type_normalized_impl(db, div, nested)
+                .map(Type::BoundMethod),
+            Type::BoundSuper(bound_super) => bound_super
+                .recursive_type_normalized_impl(db, div, nested)
+                .map(Type::BoundSuper),
+            Type::GenericAlias(generic) => generic
+                .recursive_type_normalized_impl(db, div, nested)
+                .map(Type::GenericAlias),
+            Type::SubclassOf(subclass_of) => subclass_of
+                .recursive_type_normalized_impl(db, div, nested)
+                .map(Type::SubclassOf),
             Type::TypeVar(_) => Some(self),
-            Type::KnownInstance(known_instance) => visitor.try_visit(self, || {
-                known_instance
-                    .recursive_type_normalized_impl(db, div, nested, visitor)
-                    .map(Type::KnownInstance)
-            }),
-            Type::TypeIs(type_is) => visitor.try_visit(self, || {
+            Type::KnownInstance(known_instance) => known_instance
+                .recursive_type_normalized_impl(db, div, nested)
+                .map(Type::KnownInstance),
+            Type::TypeIs(type_is) => {
                 let ty = if nested {
                     type_is
                         .return_type(db)
-                        .recursive_type_normalized_impl(db, div, true, visitor)?
+                        .recursive_type_normalized_impl(db, div, true)?
                 } else {
                     type_is
                         .return_type(db)
-                        .recursive_type_normalized_impl(db, div, true, visitor)
+                        .recursive_type_normalized_impl(db, div, true)
                         .unwrap_or(div)
                 };
                 Some(type_is.with_type(db, ty))
-            }),
+            }
             Type::Dynamic(dynamic) => Some(Type::Dynamic(dynamic.recursive_type_normalized())),
             Type::TypedDict(_) => {
                 // TODO: Normalize TypedDicts
                 Some(self)
             }
             Type::TypeAlias(_) => Some(self),
-            Type::NewTypeInstance(newtype) => visitor.try_visit(self, || {
-                newtype
-                    .try_map_base_class_type(db, |class_type| {
-                        class_type.recursive_type_normalized_impl(db, div, nested, visitor)
-                    })
-                    .map(Type::NewTypeInstance)
-            }),
+            Type::NewTypeInstance(newtype) => newtype
+                .try_map_base_class_type(db, |class_type| {
+                    class_type.recursive_type_normalized_impl(db, div, nested)
+                })
+                .map(Type::NewTypeInstance),
             Type::LiteralString
             | Type::AlwaysFalsy
             | Type::AlwaysTruthy
@@ -2115,18 +2090,25 @@ impl<'db> Type<'db> {
             // `type[T]` is a subtype of the class object `A` if every instance of `T` is a subtype of an instance
             // of `A`, and vice versa.
             (Type::SubclassOf(subclass_of), _)
-                if subclass_of.is_type_var()
-                    && !matches!(target, Type::Callable(_) | Type::ProtocolInstance(_)) =>
+                if !subclass_of
+                    .into_type_var()
+                    .zip(target.to_instance(db))
+                    .when_some_and(|(this_instance, other_instance)| {
+                        Type::TypeVar(this_instance).has_relation_to_impl(
+                            db,
+                            other_instance,
+                            inferable,
+                            relation,
+                            relation_visitor,
+                            disjointness_visitor,
+                        )
+                    })
+                    .is_never_satisfied(db) =>
             {
+                // TODO: The repetition here isn't great, but we really need the fallthrough logic,
+                // where this arm only engages if it returns true.
                 let this_instance = Type::TypeVar(subclass_of.into_type_var().unwrap());
-                let other_instance = match target {
-                    Type::Union(union) => Some(
-                        union.map(db, |element| element.to_instance(db).unwrap_or(Type::Never)),
-                    ),
-                    _ => target.to_instance(db),
-                };
-
-                other_instance.when_some_and(|other_instance| {
+                target.to_instance(db).when_some_and(|other_instance| {
                     this_instance.has_relation_to_impl(
                         db,
                         other_instance,
@@ -2137,6 +2119,7 @@ impl<'db> Type<'db> {
                     )
                 })
             }
+
             (_, Type::SubclassOf(subclass_of)) if subclass_of.is_type_var() => {
                 let other_instance = Type::TypeVar(subclass_of.into_type_var().unwrap());
                 self.to_instance(db).when_some_and(|this_instance| {
@@ -2673,6 +2656,10 @@ impl<'db> Type<'db> {
                 disjointness_visitor,
             ),
 
+            (Type::SubclassOf(subclass_of), _) if subclass_of.is_type_var() => {
+                ConstraintSet::from(false)
+            }
+
             // `Literal[<class 'C'>]` is a subtype of `type[B]` if `C` is a subclass of `B`,
             // since `type[B]` describes all possible runtime subclasses of the class object `B`.
             (Type::ClassLiteral(class), Type::SubclassOf(target_subclass_ty)) => target_subclass_ty
@@ -3107,8 +3094,7 @@ impl<'db> Type<'db> {
                 ConstraintSet::from(false)
             }
 
-            // `type[T]` is disjoint from a callable or protocol instance if its upper bound or
-            // constraints are.
+            // `type[T]` is disjoint from a callable or protocol instance if its upper bound or constraints are.
             (Type::SubclassOf(subclass_of), Type::Callable(_) | Type::ProtocolInstance(_))
             | (Type::Callable(_) | Type::ProtocolInstance(_), Type::SubclassOf(subclass_of))
                 if subclass_of.is_type_var() =>
@@ -3130,13 +3116,14 @@ impl<'db> Type<'db> {
 
             // `type[T]` is disjoint from a class object `A` if every instance of `T` is disjoint from an instance of `A`.
             (Type::SubclassOf(subclass_of), other) | (other, Type::SubclassOf(subclass_of))
-                if subclass_of.is_type_var() =>
+                if subclass_of.is_type_var()
+                    && (other.to_instance(db).is_some()
+                        || other.as_typevar().is_some_and(|type_var| {
+                            type_var.typevar(db).bound_or_constraints(db).is_none()
+                        })) =>
             {
                 let this_instance = Type::TypeVar(subclass_of.into_type_var().unwrap());
                 let other_instance = match other {
-                    Type::Union(union) => Some(
-                        union.map(db, |element| element.to_instance(db).unwrap_or(Type::Never)),
-                    ),
                     // An unbounded typevar `U` may have instances of type `object` if specialized to
                     // an instance of `type`.
                     Type::TypeVar(typevar)
@@ -3490,6 +3477,12 @@ impl<'db> Type<'db> {
                 })
             }
 
+            (Type::SubclassOf(subclass_of_ty), _) | (_, Type::SubclassOf(subclass_of_ty))
+                if subclass_of_ty.is_type_var() =>
+            {
+                ConstraintSet::from(true)
+            }
+
             (Type::SubclassOf(subclass_of_ty), Type::ClassLiteral(class_b))
             | (Type::ClassLiteral(class_b), Type::SubclassOf(subclass_of_ty)) => {
                 match subclass_of_ty.subclass_of() {
@@ -3519,31 +3512,27 @@ impl<'db> Type<'db> {
             // for `type[Any]`/`type[Unknown]`/`type[Todo]`, we know the type cannot be any larger than `type`,
             // so although the type is dynamic we can still determine disjointedness in some situations
             (Type::SubclassOf(subclass_of_ty), other)
-            | (other, Type::SubclassOf(subclass_of_ty))
-                if !subclass_of_ty.is_type_var() =>
-            {
-                match subclass_of_ty.subclass_of() {
-                    SubclassOfInner::Dynamic(_) => {
-                        KnownClass::Type.to_instance(db).is_disjoint_from_impl(
-                            db,
-                            other,
-                            inferable,
-                            disjointness_visitor,
-                            relation_visitor,
-                        )
-                    }
-                    SubclassOfInner::Class(class) => {
-                        class.metaclass_instance_type(db).is_disjoint_from_impl(
-                            db,
-                            other,
-                            inferable,
-                            disjointness_visitor,
-                            relation_visitor,
-                        )
-                    }
-                    SubclassOfInner::TypeVar(_) => unreachable!(),
+            | (other, Type::SubclassOf(subclass_of_ty)) => match subclass_of_ty.subclass_of() {
+                SubclassOfInner::Dynamic(_) => {
+                    KnownClass::Type.to_instance(db).is_disjoint_from_impl(
+                        db,
+                        other,
+                        inferable,
+                        disjointness_visitor,
+                        relation_visitor,
+                    )
                 }
-            }
+                SubclassOfInner::Class(class) => {
+                    class.metaclass_instance_type(db).is_disjoint_from_impl(
+                        db,
+                        other,
+                        inferable,
+                        disjointness_visitor,
+                        relation_visitor,
+                    )
+                }
+                SubclassOfInner::TypeVar(_) => unreachable!(),
+            },
 
             (Type::SpecialForm(special_form), Type::NominalInstance(instance))
             | (Type::NominalInstance(instance), Type::SpecialForm(special_form)) => {
@@ -3805,11 +3794,6 @@ impl<'db> Type<'db> {
                     relation_visitor,
                 )
             }
-
-            (Type::SubclassOf(_), _) | (_, Type::SubclassOf(_)) => {
-                // All cases should have been handled above.
-                unreachable!()
-            }
         }
     }
 
@@ -7403,9 +7387,6 @@ impl<'db> Type<'db> {
                 Some(KnownClass::TypeVarTuple) => Ok(todo_type!(
                     "Support for `typing.TypeVarTuple` instances in type expressions"
                 )),
-                Some(KnownClass::GenericAlias) => Ok(todo_type!(
-                    "Support for `typing.GenericAlias` instances in type expressions"
-                )),
                 _ => Err(InvalidTypeExpressionError {
                     invalid_expressions: smallvec::smallvec_inline![
                         InvalidTypeExpression::InvalidType(*self, scope_id)
@@ -8167,7 +8148,7 @@ impl<'db> Type<'db> {
             Self::AlwaysFalsy => Type::SpecialForm(SpecialFormType::AlwaysFalsy).definition(db),
 
             // These types have no definition
-            Self::Dynamic(DynamicType::Divergent(_) | DynamicType::Todo(_) | DynamicType::TodoUnpack)
+            Self::Dynamic(DynamicType::Divergent(_) | DynamicType::Todo(_) | DynamicType::TodoUnpack | DynamicType::TodoStarredExpression)
             | Self::Callable(_)
             | Self::TypeIs(_) => None,
         }
@@ -8702,7 +8683,6 @@ impl<'db> KnownInstanceType<'db> {
         db: &'db dyn Db,
         div: Type<'db>,
         nested: bool,
-        visitor: &NormalizedVisitor<'db>,
     ) -> Option<Self> {
         match self {
             // Nothing to normalize
@@ -8712,37 +8692,37 @@ impl<'db> KnownInstanceType<'db> {
             Self::ConstraintSet(set) => Some(Self::ConstraintSet(set)),
             Self::TypeVar(typevar) => Some(Self::TypeVar(typevar)),
             Self::TypeAliasType(type_alias) => type_alias
-                .recursive_type_normalized_impl(db, div, visitor)
+                .recursive_type_normalized_impl(db, div)
                 .map(Self::TypeAliasType),
             Self::Field(field) => field
-                .recursive_type_normalized_impl(db, div, nested, visitor)
+                .recursive_type_normalized_impl(db, div, nested)
                 .map(Self::Field),
             Self::UnionType(union_type) => union_type
-                .recursive_type_normalized_impl(db, div, nested, visitor)
+                .recursive_type_normalized_impl(db, div, nested)
                 .map(Self::UnionType),
             Self::Literal(ty) => ty
-                .recursive_type_normalized_impl(db, div, true, visitor)
+                .recursive_type_normalized_impl(db, div, true)
                 .map(Self::Literal),
             Self::Annotated(ty) => ty
-                .recursive_type_normalized_impl(db, div, true, visitor)
+                .recursive_type_normalized_impl(db, div, true)
                 .map(Self::Annotated),
             Self::TypeGenericAlias(ty) => ty
-                .recursive_type_normalized_impl(db, div, true, visitor)
+                .recursive_type_normalized_impl(db, div, true)
                 .map(Self::TypeGenericAlias),
             Self::LiteralStringAlias(ty) => ty
-                .recursive_type_normalized_impl(db, div, true, visitor)
+                .recursive_type_normalized_impl(db, div, true)
                 .map(Self::LiteralStringAlias),
             Self::Callable(callable) => callable
-                .recursive_type_normalized_impl(db, div, nested, visitor)
+                .recursive_type_normalized_impl(db, div, nested)
                 .map(Self::Callable),
             Self::NewType(newtype) => newtype
                 .try_map_base_class_type(db, |class_type| {
-                    class_type.recursive_type_normalized_impl(db, div, true, visitor)
+                    class_type.recursive_type_normalized_impl(db, div, true)
                 })
                 .map(Self::NewType),
             Self::GenericContext(generic) => Some(Self::GenericContext(generic)),
             Self::Specialization(specialization) => specialization
-                .recursive_type_normalized_impl(db, div, true, visitor)
+                .recursive_type_normalized_impl(db, div, true)
                 .map(Self::Specialization),
         }
     }
@@ -8829,6 +8809,8 @@ pub enum DynamicType {
     Todo(TodoType),
     /// A special Todo-variant for `Unpack[Ts]`, so that we can treat it specially in `Generic[Unpack[Ts]]`
     TodoUnpack,
+    /// A special Todo-variant for `*Ts`, so that we can treat it specially in `Generic[Unpack[Ts]]`
+    TodoStarredExpression,
     /// A type that is determined to be divergent during recursive type inference.
     Divergent(DivergentType),
 }
@@ -8859,13 +8841,8 @@ impl std::fmt::Display for DynamicType {
             // `DynamicType::Todo`'s display should be explicit that is not a valid display of
             // any other type
             DynamicType::Todo(todo) => write!(f, "@Todo{todo}"),
-            DynamicType::TodoUnpack => {
-                if cfg!(debug_assertions) {
-                    f.write_str("@Todo(typing.Unpack)")
-                } else {
-                    f.write_str("@Todo")
-                }
-            }
+            DynamicType::TodoUnpack => f.write_str("@Todo(typing.Unpack)"),
+            DynamicType::TodoStarredExpression => f.write_str("@Todo(StarredExpression)"),
             DynamicType::Divergent(_) => f.write_str("Divergent"),
         }
     }
@@ -9231,15 +9208,12 @@ impl<'db> FieldInstance<'db> {
         db: &'db dyn Db,
         div: Type<'db>,
         nested: bool,
-        visitor: &NormalizedVisitor<'db>,
     ) -> Option<Self> {
         let default_type = match self.default_type(db) {
-            Some(default) if nested => {
-                Some(default.recursive_type_normalized_impl(db, div, true, visitor)?)
-            }
+            Some(default) if nested => Some(default.recursive_type_normalized_impl(db, div, true)?),
             Some(default) => Some(
                 default
-                    .recursive_type_normalized_impl(db, div, true, visitor)
+                    .recursive_type_normalized_impl(db, div, true)
                     .unwrap_or(div),
             ),
             None => None,
@@ -10184,7 +10158,6 @@ impl<'db> UnionTypeInstance<'db> {
         db: &'db dyn Db,
         div: Type<'db>,
         nested: bool,
-        visitor: &NormalizedVisitor<'db>,
     ) -> Option<Self> {
         // The `Divergent` elimination rules are different within union types.
         // See `UnionType::recursive_type_normalized_impl` for details.
@@ -10192,14 +10165,14 @@ impl<'db> UnionTypeInstance<'db> {
             Some(types) if nested => Some(
                 types
                     .iter()
-                    .map(|ty| ty.recursive_type_normalized_impl(db, div, nested, visitor))
+                    .map(|ty| ty.recursive_type_normalized_impl(db, div, nested))
                     .collect::<Option<Box<_>>>()?,
             ),
             Some(types) => Some(
                 types
                     .iter()
                     .map(|ty| {
-                        ty.recursive_type_normalized_impl(db, div, nested, visitor)
+                        ty.recursive_type_normalized_impl(db, div, nested)
                             .unwrap_or(div)
                     })
                     .collect::<Box<_>>(),
@@ -10207,9 +10180,9 @@ impl<'db> UnionTypeInstance<'db> {
             None => None,
         };
         let union_type = match self.union_type(db).clone() {
-            Ok(ty) if nested => Ok(ty.recursive_type_normalized_impl(db, div, nested, visitor)?),
+            Ok(ty) if nested => Ok(ty.recursive_type_normalized_impl(db, div, nested)?),
             Ok(ty) => Ok(ty
-                .recursive_type_normalized_impl(db, div, nested, visitor)
+                .recursive_type_normalized_impl(db, div, nested)
                 .unwrap_or(div)),
             Err(err) => Err(err),
         };
@@ -10241,14 +10214,13 @@ impl<'db> InternedType<'db> {
         db: &'db dyn Db,
         div: Type<'db>,
         nested: bool,
-        visitor: &NormalizedVisitor<'db>,
     ) -> Option<Self> {
         let inner = if nested {
             self.inner(db)
-                .recursive_type_normalized_impl(db, div, nested, visitor)?
+                .recursive_type_normalized_impl(db, div, nested)?
         } else {
             self.inner(db)
-                .recursive_type_normalized_impl(db, div, nested, visitor)
+                .recursive_type_normalized_impl(db, div, nested)
                 .unwrap_or(div)
         };
         Some(InternedType::new(db, inner))
@@ -11560,14 +11532,13 @@ impl<'db> BoundMethodType<'db> {
         db: &'db dyn Db,
         div: Type<'db>,
         nested: bool,
-        visitor: &NormalizedVisitor<'db>,
     ) -> Option<Self> {
         Some(Self::new(
             db,
             self.function(db)
-                .recursive_type_normalized_impl(db, div, nested, visitor)?,
+                .recursive_type_normalized_impl(db, div, nested)?,
             self.self_instance(db)
-                .recursive_type_normalized_impl(db, div, true, visitor)?,
+                .recursive_type_normalized_impl(db, div, true)?,
         ))
     }
 
@@ -11732,12 +11703,11 @@ impl<'db> CallableType<'db> {
         db: &'db dyn Db,
         div: Type<'db>,
         nested: bool,
-        visitor: &NormalizedVisitor<'db>,
     ) -> Option<Self> {
         Some(CallableType::new(
             db,
             self.signatures(db)
-                .recursive_type_normalized_impl(db, div, nested, visitor)?,
+                .recursive_type_normalized_impl(db, div, nested)?,
             self.is_function_like(db),
         ))
     }
@@ -12175,27 +12145,26 @@ impl<'db> KnownBoundMethodType<'db> {
         db: &'db dyn Db,
         div: Type<'db>,
         nested: bool,
-        visitor: &NormalizedVisitor<'db>,
     ) -> Option<Self> {
         match self {
             KnownBoundMethodType::FunctionTypeDunderGet(function) => {
                 Some(KnownBoundMethodType::FunctionTypeDunderGet(
-                    function.recursive_type_normalized_impl(db, div, nested, visitor)?,
+                    function.recursive_type_normalized_impl(db, div, nested)?,
                 ))
             }
             KnownBoundMethodType::FunctionTypeDunderCall(function) => {
                 Some(KnownBoundMethodType::FunctionTypeDunderCall(
-                    function.recursive_type_normalized_impl(db, div, nested, visitor)?,
+                    function.recursive_type_normalized_impl(db, div, nested)?,
                 ))
             }
             KnownBoundMethodType::PropertyDunderGet(property) => {
                 Some(KnownBoundMethodType::PropertyDunderGet(
-                    property.recursive_type_normalized_impl(db, div, nested, visitor)?,
+                    property.recursive_type_normalized_impl(db, div, nested)?,
                 ))
             }
             KnownBoundMethodType::PropertyDunderSet(property) => {
                 Some(KnownBoundMethodType::PropertyDunderSet(
-                    property.recursive_type_normalized_impl(db, div, nested, visitor)?,
+                    property.recursive_type_normalized_impl(db, div, nested)?,
                 ))
             }
             KnownBoundMethodType::StrStartswith(_)
@@ -12858,18 +12827,14 @@ impl<'db> ManualPEP695TypeAliasType<'db> {
         )
     }
 
-    fn recursive_type_normalized_impl(
-        self,
-        db: &'db dyn Db,
-        div: Type<'db>,
-        visitor: &NormalizedVisitor<'db>,
-    ) -> Option<Self> {
+    // TODO: with full support for manual PEP-695 style type aliases, this method should become unnecessary.
+    fn recursive_type_normalized_impl(self, db: &'db dyn Db, div: Type<'db>) -> Option<Self> {
         Some(Self::new(
             db,
             self.name(db),
             self.definition(db),
             self.value(db)
-                .recursive_type_normalized_impl(db, div, true, visitor)?,
+                .recursive_type_normalized_impl(db, div, true)?,
         ))
     }
 }
@@ -12914,16 +12879,11 @@ impl<'db> TypeAliasType<'db> {
         }
     }
 
-    fn recursive_type_normalized_impl(
-        self,
-        db: &'db dyn Db,
-        div: Type<'db>,
-        visitor: &NormalizedVisitor<'db>,
-    ) -> Option<Self> {
+    fn recursive_type_normalized_impl(self, db: &'db dyn Db, div: Type<'db>) -> Option<Self> {
         match self {
             TypeAliasType::PEP695(type_alias) => Some(TypeAliasType::PEP695(type_alias)),
             TypeAliasType::ManualPEP695(type_alias) => Some(TypeAliasType::ManualPEP695(
-                type_alias.recursive_type_normalized_impl(db, div, visitor)?,
+                type_alias.recursive_type_normalized_impl(db, div)?,
             )),
         }
     }
@@ -13248,7 +13208,6 @@ impl<'db> UnionType<'db> {
         db: &'db dyn Db,
         div: Type<'db>,
         nested: bool,
-        visitor: &NormalizedVisitor<'db>,
     ) -> Option<Type<'db>> {
         let mut builder = UnionBuilder::new(db)
             .order_elements(false)
@@ -13258,7 +13217,7 @@ impl<'db> UnionType<'db> {
         for ty in self.elements(db) {
             if nested {
                 // list[T | Divergent] => list[Divergent]
-                let ty = ty.recursive_type_normalized_impl(db, div, nested, visitor)?;
+                let ty = ty.recursive_type_normalized_impl(db, div, nested)?;
                 if ty == div {
                     return Some(ty);
                 }
@@ -13271,7 +13230,7 @@ impl<'db> UnionType<'db> {
                     continue;
                 }
                 builder = builder.add(
-                    ty.recursive_type_normalized_impl(db, div, nested, visitor)
+                    ty.recursive_type_normalized_impl(db, div, nested)
                         .unwrap_or(div),
                 );
                 empty = false;
@@ -13389,18 +13348,16 @@ impl<'db> IntersectionType<'db> {
         db: &'db dyn Db,
         div: Type<'db>,
         nested: bool,
-        visitor: &NormalizedVisitor<'db>,
     ) -> Option<Self> {
         fn opt_normalized_set<'db>(
             db: &'db dyn Db,
             elements: &FxOrderSet<Type<'db>>,
             div: Type<'db>,
             nested: bool,
-            visitor: &NormalizedVisitor<'db>,
         ) -> Option<FxOrderSet<Type<'db>>> {
             elements
                 .iter()
-                .map(|ty| ty.recursive_type_normalized_impl(db, div, nested, visitor))
+                .map(|ty| ty.recursive_type_normalized_impl(db, div, nested))
                 .collect()
         }
 
@@ -13409,26 +13366,25 @@ impl<'db> IntersectionType<'db> {
             elements: &FxOrderSet<Type<'db>>,
             div: Type<'db>,
             nested: bool,
-            visitor: &NormalizedVisitor<'db>,
         ) -> FxOrderSet<Type<'db>> {
             elements
                 .iter()
                 .map(|ty| {
-                    ty.recursive_type_normalized_impl(db, div, nested, visitor)
+                    ty.recursive_type_normalized_impl(db, div, nested)
                         .unwrap_or(div)
                 })
                 .collect()
         }
 
         let positive = if nested {
-            opt_normalized_set(db, self.positive(db), div, nested, visitor)?
+            opt_normalized_set(db, self.positive(db), div, nested)?
         } else {
-            normalized_set(db, self.positive(db), div, nested, visitor)
+            normalized_set(db, self.positive(db), div, nested)
         };
         let negative = if nested {
-            opt_normalized_set(db, self.negative(db), div, nested, visitor)?
+            opt_normalized_set(db, self.negative(db), div, nested)?
         } else {
-            normalized_set(db, self.negative(db), div, nested, visitor)
+            normalized_set(db, self.negative(db), div, nested)
         };
 
         Some(IntersectionType::new(db, positive, negative))
@@ -13911,16 +13867,15 @@ pub(crate) mod tests {
             nested_rec.display(&db).to_string(),
             "list[list[Divergent] | None]"
         );
-        let visitor = NormalizedVisitor::default();
         let normalized = nested_rec
-            .recursive_type_normalized_impl(&db, div, false, &visitor)
+            .recursive_type_normalized_impl(&db, div, false)
             .unwrap();
         assert_eq!(normalized.display(&db).to_string(), "list[Divergent]");
 
         let union = UnionType::from_elements(&db, [div, KnownClass::Int.to_instance(&db)]);
         assert_eq!(union.display(&db).to_string(), "Divergent | int");
         let normalized = union
-            .recursive_type_normalized_impl(&db, div, false, &visitor)
+            .recursive_type_normalized_impl(&db, div, false)
             .unwrap();
         assert_eq!(normalized.display(&db).to_string(), "int");
 

crates/ty_python_semantic/src/types/bound_super.rs

@@ -197,17 +197,16 @@ impl<'db> SuperOwnerKind<'db> {
         db: &'db dyn Db,
         div: Type<'db>,
         nested: bool,
-        visitor: &NormalizedVisitor<'db>,
     ) -> Option<Self> {
         match self {
             SuperOwnerKind::Dynamic(dynamic) => {
                 Some(SuperOwnerKind::Dynamic(dynamic.recursive_type_normalized()))
             }
             SuperOwnerKind::Class(class) => Some(SuperOwnerKind::Class(
-                class.recursive_type_normalized_impl(db, div, nested, visitor)?,
+                class.recursive_type_normalized_impl(db, div, nested)?,
             )),
             SuperOwnerKind::Instance(instance) => Some(SuperOwnerKind::Instance(
-                instance.recursive_type_normalized_impl(db, div, nested, visitor)?,
+                instance.recursive_type_normalized_impl(db, div, nested)?,
             )),
         }
     }
@@ -620,14 +619,13 @@ impl<'db> BoundSuperType<'db> {
         db: &'db dyn Db,
         div: Type<'db>,
         nested: bool,
-        visitor: &NormalizedVisitor<'db>,
     ) -> Option<Self> {
         Some(Self::new(
             db,
             self.pivot_class(db)
-                .recursive_type_normalized_impl(db, div, nested, visitor)?,
+                .recursive_type_normalized_impl(db, div, nested)?,
             self.owner(db)
-                .recursive_type_normalized_impl(db, div, nested, visitor)?,
+                .recursive_type_normalized_impl(db, div, nested)?,
         ))
     }
 }

crates/ty_python_semantic/src/types/call/bind.rs

@@ -39,7 +39,7 @@ use crate::types::{
     DataclassParams, FieldInstance, KnownBoundMethodType, KnownClass, KnownInstanceType,
     MemberLookupPolicy, NominalInstanceType, PropertyInstanceType, SpecialFormType,
     TrackedConstraintSet, TypeAliasType, TypeContext, TypeVarVariance, UnionBuilder, UnionType,
-    WrapperDescriptorKind, enums, ide_support, todo_type,
+    WrapperDescriptorKind, enums, list_members, todo_type,
 };
 use ruff_db::diagnostic::{Annotation, Diagnostic, SubDiagnostic, SubDiagnosticSeverity};
 use ruff_python_ast::{self as ast, ArgOrKeyword, PythonVersion};
@@ -888,7 +888,7 @@ impl<'db> Bindings<'db> {
                             if let [Some(ty)] = overload.parameter_types() {
                                 overload.set_return_type(Type::heterogeneous_tuple(
                                     db,
-                                    ide_support::all_members(db, *ty)
+                                    list_members::all_members(db, *ty)
                                         .into_iter()
                                         .sorted()
                                         .map(|member| Type::string_literal(db, &member.name)),

crates/ty_python_semantic/src/types/class.rs

@@ -19,7 +19,7 @@ use crate::semantic_index::{
 use crate::types::bound_super::BoundSuperError;
 use crate::types::constraints::{ConstraintSet, IteratorConstraintsExtension};
 use crate::types::context::InferContext;
-use crate::types::diagnostic::INVALID_TYPE_ALIAS_TYPE;
+use crate::types::diagnostic::{INVALID_TYPE_ALIAS_TYPE, SUPER_CALL_IN_NAMED_TUPLE_METHOD};
 use crate::types::enums::enum_metadata;
 use crate::types::function::{DataclassTransformerParams, KnownFunction};
 use crate::types::generics::{
@@ -284,13 +284,12 @@ impl<'db> GenericAlias<'db> {
         db: &'db dyn Db,
         div: Type<'db>,
         nested: bool,
-        visitor: &NormalizedVisitor<'db>,
     ) -> Option<Self> {
         Some(Self::new(
             db,
             self.origin(db),
             self.specialization(db)
-                .recursive_type_normalized_impl(db, div, nested, visitor)?,
+                .recursive_type_normalized_impl(db, div, nested)?,
         ))
     }
 
@@ -443,12 +442,11 @@ impl<'db> ClassType<'db> {
         db: &'db dyn Db,
         div: Type<'db>,
         nested: bool,
-        visitor: &NormalizedVisitor<'db>,
     ) -> Option<Self> {
         match self {
             Self::NonGeneric(_) => Some(self),
             Self::Generic(generic) => Some(Self::Generic(
-                generic.recursive_type_normalized_impl(db, div, nested, visitor)?,
+                generic.recursive_type_normalized_impl(db, div, nested)?,
             )),
         }
     }
@@ -5546,6 +5544,20 @@ impl KnownClass {
                             return;
                         };
 
+                        // Check if the enclosing class is a `NamedTuple`, which forbids the use of `super()`.
+                        if CodeGeneratorKind::NamedTuple.matches(db, enclosing_class, None) {
+                            if let Some(builder) = context
+                                .report_lint(&SUPER_CALL_IN_NAMED_TUPLE_METHOD, call_expression)
+                            {
+                                builder.into_diagnostic(format_args!(
+                                    "Cannot use `super()` in a method of NamedTuple class `{}`",
+                                    enclosing_class.name(db)
+                                ));
+                            }
+                            overload.set_return_type(Type::unknown());
+                            return;
+                        }
+
                         // The type of the first parameter if the given scope is function-like (i.e. function or lambda).
                         // `None` if the scope is not function-like, or has no parameters.
                         let first_param = match scope.node(db) {
@@ -5585,6 +5597,22 @@ impl KnownClass {
                         overload.set_return_type(bound_super);
                     }
                     [Some(pivot_class_type), Some(owner_type)] => {
+                        // Check if the enclosing class is a `NamedTuple`, which forbids the use of `super()`.
+                        if let Some(enclosing_class) = nearest_enclosing_class(db, index, scope) {
+                            if CodeGeneratorKind::NamedTuple.matches(db, enclosing_class, None) {
+                                if let Some(builder) = context
+                                    .report_lint(&SUPER_CALL_IN_NAMED_TUPLE_METHOD, call_expression)
+                                {
+                                    builder.into_diagnostic(format_args!(
+                                        "Cannot use `super()` in a method of NamedTuple class `{}`",
+                                        enclosing_class.name(db)
+                                    ));
+                                }
+                                overload.set_return_type(Type::unknown());
+                                return;
+                            }
+                        }
+
                         let bound_super = BoundSuperType::build(db, *pivot_class_type, *owner_type)
                             .unwrap_or_else(|err| {
                                 err.report_diagnostic(context, call_expression.into());

crates/ty_python_semantic/src/types/class_base.rs

@@ -48,12 +48,11 @@ impl<'db> ClassBase<'db> {
         db: &'db dyn Db,
         div: Type<'db>,
         nested: bool,
-        visitor: &NormalizedVisitor<'db>,
     ) -> Option<Self> {
         match self {
             Self::Dynamic(dynamic) => Some(Self::Dynamic(dynamic.recursive_type_normalized())),
             Self::Class(class) => Some(Self::Class(
-                class.recursive_type_normalized_impl(db, div, nested, visitor)?,
+                class.recursive_type_normalized_impl(db, div, nested)?,
             )),
             Self::Protocol | Self::Generic | Self::TypedDict => Some(self),
         }
@@ -64,7 +63,9 @@ impl<'db> ClassBase<'db> {
             ClassBase::Class(class) => class.name(db),
             ClassBase::Dynamic(DynamicType::Any) => "Any",
             ClassBase::Dynamic(DynamicType::Unknown) => "Unknown",
-            ClassBase::Dynamic(DynamicType::Todo(_) | DynamicType::TodoUnpack) => "@Todo",
+            ClassBase::Dynamic(
+                DynamicType::Todo(_) | DynamicType::TodoUnpack | DynamicType::TodoStarredExpression,
+            ) => "@Todo",
             ClassBase::Dynamic(DynamicType::Divergent(_)) => "Divergent",
             ClassBase::Protocol => "Protocol",
             ClassBase::Generic => "Generic",

crates/ty_python_semantic/src/types/constraints.rs

@@ -418,6 +418,7 @@ impl<'db> ConstraintSet<'db> {
         Self::constrain_typevar(db, typevar, lower, upper, TypeRelation::Assignability)
     }
 
+    #[expect(dead_code)] // Keep this around for debugging purposes
     pub(crate) fn display(self, db: &'db dyn Db) -> impl Display {
         self.node.simplify_for_display(db).display(db)
     }

crates/ty_python_semantic/src/types/diagnostic.rs

@@ -18,7 +18,7 @@ use crate::types::class::{
     CodeGeneratorKind, DisjointBase, DisjointBaseKind, Field, MethodDecorator,
 };
 use crate::types::function::{FunctionDecorators, FunctionType, KnownFunction, OverloadLiteral};
-use crate::types::liskov::MethodKind;
+use crate::types::overrides::MethodKind;
 use crate::types::string_annotation::{
     BYTE_STRING_TYPE_ANNOTATION, ESCAPE_CHARACTER_IN_FORWARD_ANNOTATION, FSTRING_TYPE_ANNOTATION,
     IMPLICIT_CONCATENATED_STRING_TYPE_ANNOTATION, INVALID_SYNTAX_IN_FORWARD_ANNOTATION,
@@ -121,6 +121,7 @@ pub(crate) fn register_lints(registry: &mut LintRegistryBuilder) {
     registry.register_lint(&MISSING_TYPED_DICT_KEY);
     registry.register_lint(&INVALID_METHOD_OVERRIDE);
     registry.register_lint(&INVALID_EXPLICIT_OVERRIDE);
+    registry.register_lint(&SUPER_CALL_IN_NAMED_TUPLE_METHOD);
 
     // String annotations
     registry.register_lint(&BYTE_STRING_TYPE_ANNOTATION);
@@ -544,7 +545,8 @@ declare_lint! {
     ///
     /// ## Why is this bad?
     /// An invalidly defined `NamedTuple` class may lead to the type checker
-    /// drawing incorrect conclusions. It may also lead to `TypeError`s at runtime.
+    /// drawing incorrect conclusions. It may also lead to `TypeError`s or
+    /// `AttributeError`s at runtime.
     ///
     /// ## Examples
     /// A class definition cannot combine `NamedTuple` with other base classes
@@ -557,6 +559,27 @@ declare_lint! {
     /// >>> class Foo(NamedTuple, object): ...
     /// TypeError: can only inherit from a NamedTuple type and Generic
     /// ```
+    ///
+    /// Further, `NamedTuple` field names cannot start with an underscore:
+    ///
+    /// ```pycon
+    /// >>> from typing import NamedTuple
+    /// >>> class Foo(NamedTuple):
+    /// ...     _bar: int
+    /// ValueError: Field names cannot start with an underscore: '_bar'
+    /// ```
+    ///
+    /// `NamedTuple` classes also have certain synthesized attributes (like `_asdict`, `_make`,
+    /// `_replace`, etc.) that cannot be overwritten. Attempting to assign to these attributes
+    /// without a type annotation will raise an `AttributeError` at runtime.
+    ///
+    /// ```pycon
+    /// >>> from typing import NamedTuple
+    /// >>> class Foo(NamedTuple):
+    /// ...     x: int
+    /// ...     _asdict = 42
+    /// AttributeError: Cannot overwrite NamedTuple attribute _asdict
+    /// ```
     pub(crate) static INVALID_NAMED_TUPLE = {
         summary: "detects invalid `NamedTuple` class definitions",
         status: LintStatus::stable("0.0.1-alpha.19"),
@@ -1760,6 +1783,33 @@ declare_lint! {
     }
 }
 
+declare_lint! {
+    /// ## What it does
+    /// Checks for calls to `super()` inside methods of `NamedTuple` classes.
+    ///
+    /// ## Why is this bad?
+    /// Using `super()` in a method of a `NamedTuple` class will raise an exception at runtime.
+    ///
+    /// ## Examples
+    /// ```python
+    /// from typing import NamedTuple
+    ///
+    /// class F(NamedTuple):
+    ///     x: int
+    ///
+    ///     def method(self):
+    ///         super()  # error: super() is not supported in methods of NamedTuple classes
+    /// ```
+    ///
+    /// ## References
+    /// - [Python documentation: super()](https://docs.python.org/3/library/functions.html#super)
+    pub(crate) static SUPER_CALL_IN_NAMED_TUPLE_METHOD = {
+        summary: "detects `super()` calls in methods of `NamedTuple` classes",
+        status: LintStatus::preview("0.0.1-alpha.30"),
+        default_level: Level::Error,
+    }
+}
+
 declare_lint! {
     /// ## What it does
     /// Checks for calls to `reveal_type` without importing it.
@@ -3501,7 +3551,7 @@ pub(crate) fn report_invalid_key_on_typed_dict<'db>(
 pub(super) fn report_namedtuple_field_without_default_after_field_with_default<'db>(
     context: &InferContext<'db, '_>,
     class: ClassLiteral<'db>,
-    (field, field_def): &(Name, Option<Definition<'db>>),
+    (field, field_def): (&str, Option<Definition<'db>>),
     (field_with_default, field_with_default_def): &(Name, Option<Definition<'db>>),
 ) {
     let db = context.db();
@@ -3514,9 +3564,9 @@ pub(super) fn report_namedtuple_field_without_default_after_field_with_default<'
     let Some(builder) = context.report_lint(&INVALID_NAMED_TUPLE, diagnostic_range) else {
         return;
     };
-    let mut diagnostic = builder.into_diagnostic(format_args!(
+    let mut diagnostic = builder.into_diagnostic(
         "NamedTuple field without default value cannot follow field(s) with default value(s)",
-    ));
+    );
 
     diagnostic.set_primary_message(format_args!(
         "Field `{field}` defined here without a default value",
@@ -3547,6 +3597,40 @@ pub(super) fn report_namedtuple_field_without_default_after_field_with_default<'
     }
 }
 
+pub(super) fn report_named_tuple_field_with_leading_underscore<'db>(
+    context: &InferContext<'db, '_>,
+    class: ClassLiteral<'db>,
+    field_name: &str,
+    field_definition: Option<Definition<'db>>,
+) {
+    let db = context.db();
+    let module = context.module();
+
+    let diagnostic_range = field_definition
+        .map(|definition| definition.kind(db).full_range(module))
+        .unwrap_or_else(|| class.header_range(db));
+
+    let Some(builder) = context.report_lint(&INVALID_NAMED_TUPLE, diagnostic_range) else {
+        return;
+    };
+    let mut diagnostic =
+        builder.into_diagnostic("NamedTuple field name cannot start with an underscore");
+
+    if field_definition.is_some() {
+        diagnostic.set_primary_message(
+            "Class definition will raise `TypeError` at runtime due to this field",
+        );
+    } else {
+        diagnostic.set_primary_message(format_args!(
+            "Class definition will raise `TypeError` at runtime due to field `{field_name}`",
+        ));
+    }
+
+    diagnostic.set_concise_message(format_args!(
+        "NamedTuple field `{field_name}` cannot start with an underscore"
+    ));
+}
+
 pub(crate) fn report_missing_typed_dict_key<'db>(
     context: &InferContext<'db, '_>,
     constructor_node: AnyNodeRef,
@@ -3804,6 +3888,7 @@ pub(super) fn report_overridden_final_method<'db>(
     context: &InferContext<'db, '_>,
     member: &str,
     subclass_definition: Definition<'db>,
+    // N.B. the type of the *definition*, not the type on an instance of the subclass
     subclass_type: Type<'db>,
     superclass: ClassType<'db>,
     subclass: ClassType<'db>,
@@ -3811,6 +3896,23 @@ pub(super) fn report_overridden_final_method<'db>(
 ) {
     let db = context.db();
 
+    // Some hijinks so that we emit a diagnostic on the property getter rather than the property setter
+    let property_getter_definition = if subclass_definition.kind(db).is_function_def()
+        && let Type::PropertyInstance(property) = subclass_type
+        && let Some(Type::FunctionLiteral(getter)) = property.getter(db)
+    {
+        let getter_definition = getter.definition(db);
+        if getter_definition.scope(db) == subclass_definition.scope(db) {
+            Some(getter_definition)
+        } else {
+            None
+        }
+    } else {
+        None
+    };
+
+    let subclass_definition = property_getter_definition.unwrap_or(subclass_definition);
+
     let Some(builder) = context.report_lint(
         &OVERRIDE_OF_FINAL_METHOD,
         subclass_definition.focus_range(db, context.module()),
@@ -3871,37 +3973,69 @@ pub(super) fn report_overridden_final_method<'db>(
 
     diagnostic.sub(sub);
 
-    let underlying_function = match subclass_type {
-        Type::FunctionLiteral(function) => Some(function),
-        Type::BoundMethod(method) => Some(method.function(db)),
-        _ => None,
-    };
+    // It's tempting to autofix properties as well,
+    // but you'd want to delete the `@my_property.deleter` as well as the getter and the deleter,
+    // and we don't model property deleters at all right now.
+    if let Type::FunctionLiteral(function) = subclass_type {
+        let class_node = subclass
+            .class_literal(db)
+            .0
+            .body_scope(db)
+            .node(db)
+            .expect_class()
+            .node(context.module());
+
+        let (overloads, implementation) = function.overloads_and_implementation(db);
+        let overload_count = overloads.len() + usize::from(implementation.is_some());
+        let is_only = overload_count >= class_node.body.len();
 
-    if let Some(function) = underlying_function {
         let overload_deletion = |overload: &OverloadLiteral<'db>| {
-            Edit::range_deletion(overload.node(db, context.file(), context.module()).range())
+            let range = overload.node(db, context.file(), context.module()).range();
+            if is_only {
+                Edit::range_replacement("pass".to_string(), range)
+            } else {
+                Edit::range_deletion(range)
+            }
         };
 
+        let should_fix = overloads
+            .iter()
+            .copied()
+            .chain(implementation)
+            .all(|overload| {
+                class_node
+                    .body
+                    .iter()
+                    .filter_map(ast::Stmt::as_function_def_stmt)
+                    .contains(overload.node(db, context.file(), context.module()))
+            });
+
         match function.overloads_and_implementation(db) {
             ([first_overload, rest @ ..], None) => {
                 diagnostic.help(format_args!("Remove all overloads for `{member}`"));
-                diagnostic.set_fix(Fix::unsafe_edits(
-                    overload_deletion(first_overload),
-                    rest.iter().map(overload_deletion),
-                ));
+                diagnostic.set_optional_fix(should_fix.then(|| {
+                    Fix::unsafe_edits(
+                        overload_deletion(first_overload),
+                        rest.iter().map(overload_deletion),
+                    )
+                }));
             }
             ([first_overload, rest @ ..], Some(implementation)) => {
                 diagnostic.help(format_args!(
                     "Remove all overloads and the implementation for `{member}`"
                 ));
-                diagnostic.set_fix(Fix::unsafe_edits(
-                    overload_deletion(first_overload),
-                    rest.iter().chain([&implementation]).map(overload_deletion),
-                ));
+                diagnostic.set_optional_fix(should_fix.then(|| {
+                    Fix::unsafe_edits(
+                        overload_deletion(first_overload),
+                        rest.iter().chain([&implementation]).map(overload_deletion),
+                    )
+                }));
             }
             ([], Some(implementation)) => {
                 diagnostic.help(format_args!("Remove the override of `{member}`"));
-                diagnostic.set_fix(Fix::unsafe_edit(overload_deletion(&implementation)));
+                diagnostic.set_optional_fix(
+                    should_fix.then(|| Fix::unsafe_edit(overload_deletion(&implementation))),
+                );
             }
             ([], None) => {
                 // Should be impossible to get here: how would we even infer a function as a function
@@ -3911,11 +4045,12 @@ pub(super) fn report_overridden_final_method<'db>(
                 );
             }
         }
+    } else if let Type::PropertyInstance(property) = subclass_type
+        && property.setter(db).is_some()
+    {
+        diagnostic.help(format_args!("Remove the getter and setter for `{member}`"));
     } else {
         diagnostic.help(format_args!("Remove the override of `{member}`"));
-        diagnostic.set_fix(Fix::unsafe_edit(Edit::range_deletion(
-            subclass_definition.full_range(db, context.module()).range(),
-        )));
     }
 }