Zizmor

This reverts commit 82dc27f2680b8085280136848ffe2ee1d2952a4e.

.github/workflows/build-binaries.yml

@@ -49,7 +49,7 @@ jobs:
       - name: "Prep README.md"
         run: python scripts/transform_readme.py --target pypi
       - name: "Build sdist"
-        uses: PyO3/maturin-action@35be3186fc8e037e329f06b68dcd807d83dcc6dc # v1.49.2
+        uses: PyO3/maturin-action@e10f6c464b90acceb5f640d31beda6d586ba7b4a # v1.49.3
         with:
           command: sdist
           args: --out dist
@@ -79,7 +79,7 @@ jobs:
       - name: "Prep README.md"
         run: python scripts/transform_readme.py --target pypi
       - name: "Build wheels - x86_64"
-        uses: PyO3/maturin-action@35be3186fc8e037e329f06b68dcd807d83dcc6dc # v1.49.2
+        uses: PyO3/maturin-action@e10f6c464b90acceb5f640d31beda6d586ba7b4a # v1.49.3
         with:
           target: x86_64
           args: --release --locked --out dist
@@ -121,7 +121,7 @@ jobs:
       - name: "Prep README.md"
         run: python scripts/transform_readme.py --target pypi
       - name: "Build wheels - aarch64"
-        uses: PyO3/maturin-action@35be3186fc8e037e329f06b68dcd807d83dcc6dc # v1.49.2
+        uses: PyO3/maturin-action@e10f6c464b90acceb5f640d31beda6d586ba7b4a # v1.49.3
         with:
           target: aarch64
           args: --release --locked --out dist
@@ -177,7 +177,7 @@ jobs:
       - name: "Prep README.md"
         run: python scripts/transform_readme.py --target pypi
       - name: "Build wheels"
-        uses: PyO3/maturin-action@35be3186fc8e037e329f06b68dcd807d83dcc6dc # v1.49.2
+        uses: PyO3/maturin-action@e10f6c464b90acceb5f640d31beda6d586ba7b4a # v1.49.3
         with:
           target: ${{ matrix.platform.target }}
           args: --release --locked --out dist
@@ -230,7 +230,7 @@ jobs:
       - name: "Prep README.md"
         run: python scripts/transform_readme.py --target pypi
       - name: "Build wheels"
-        uses: PyO3/maturin-action@35be3186fc8e037e329f06b68dcd807d83dcc6dc # v1.49.2
+        uses: PyO3/maturin-action@e10f6c464b90acceb5f640d31beda6d586ba7b4a # v1.49.3
         with:
           target: ${{ matrix.target }}
           manylinux: auto
@@ -304,7 +304,7 @@ jobs:
       - name: "Prep README.md"
         run: python scripts/transform_readme.py --target pypi
       - name: "Build wheels"
-        uses: PyO3/maturin-action@35be3186fc8e037e329f06b68dcd807d83dcc6dc # v1.49.2
+        uses: PyO3/maturin-action@e10f6c464b90acceb5f640d31beda6d586ba7b4a # v1.49.3
         with:
           target: ${{ matrix.platform.target }}
           manylinux: auto
@@ -370,7 +370,7 @@ jobs:
       - name: "Prep README.md"
         run: python scripts/transform_readme.py --target pypi
       - name: "Build wheels"
-        uses: PyO3/maturin-action@35be3186fc8e037e329f06b68dcd807d83dcc6dc # v1.49.2
+        uses: PyO3/maturin-action@e10f6c464b90acceb5f640d31beda6d586ba7b4a # v1.49.3
         with:
           target: ${{ matrix.target }}
           manylinux: musllinux_1_2
@@ -435,7 +435,7 @@ jobs:
       - name: "Prep README.md"
         run: python scripts/transform_readme.py --target pypi
       - name: "Build wheels"
-        uses: PyO3/maturin-action@35be3186fc8e037e329f06b68dcd807d83dcc6dc # v1.49.2
+        uses: PyO3/maturin-action@e10f6c464b90acceb5f640d31beda6d586ba7b4a # v1.49.3
         with:
           target: ${{ matrix.platform.target }}
           manylinux: musllinux_1_2

.github/workflows/ci.yaml

@@ -321,14 +321,30 @@ jobs:
       - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
         with:
           persist-credentials: false
+      - name: Setup Dev Drive
+        run: ${{ github.workspace }}/.github/workflows/setup-dev-drive.ps1
+
+      # actions/checkout does not let us clone into anywhere outside `github.workspace`, so we have to copy the clone
+      - name: Copy Git Repo to Dev Drive
+        env:
+          RUFF_WORKSPACE: ${{ env.RUFF_WORKSPACE }}
+        run: |
+          Copy-Item -Path "${{ github.workspace }}" -Destination "${env:RUFF_WORKSPACE}" -Recurse
+
       - uses: Swatinem/rust-cache@9d47c6ad4b02e050fd481d890b2ea34778fd09d6 # v2.7.8
+        with:
+          workspaces: ${{ env.RUFF_WORKSPACE }}
+
       - name: "Install Rust toolchain"
+        working-directory: ${{ env.RUFF_WORKSPACE }}
         run: rustup show
+
       - name: "Install cargo nextest"
         uses: taiki-e/install-action@d12e869b89167df346dd0ff65da342d1fb1202fb # v2.53.2
         with:
           tool: cargo-nextest
       - name: "Run tests"
+        working-directory: ${{ env.RUFF_WORKSPACE }}
         shell: bash
         env:
           NEXTEST_PROFILE: "ci"
@@ -460,7 +476,7 @@ jobs:
       - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
         with:
           persist-credentials: false
-      - uses: astral-sh/setup-uv@445689ea25e0de0a23313031f5fe577c74ae45a1 # v6.3.0
+      - uses: astral-sh/setup-uv@bd01e18f51369d5a26f1651c3cb451d3417e3bba # v6.3.1
       - uses: actions/download-artifact@d3f86a106a0bac45b974a628896c90dbdf5c8093 # v4.3.0
         name: Download Ruff binary to test
         id: download-cached-binary
@@ -661,7 +677,7 @@ jobs:
           branch: ${{ github.event.pull_request.base.ref }}
           workflow: "ci.yaml"
           check_artifacts: true
-      - uses: astral-sh/setup-uv@445689ea25e0de0a23313031f5fe577c74ae45a1 # v6.3.0
+      - uses: astral-sh/setup-uv@bd01e18f51369d5a26f1651c3cb451d3417e3bba # v6.3.1
       - name: Fuzz
         env:
           FORCE_COLOR: 1
@@ -712,7 +728,7 @@ jobs:
       - name: "Prep README.md"
         run: python scripts/transform_readme.py --target pypi
       - name: "Build wheels"
-        uses: PyO3/maturin-action@35be3186fc8e037e329f06b68dcd807d83dcc6dc # v1.49.2
+        uses: PyO3/maturin-action@e10f6c464b90acceb5f640d31beda6d586ba7b4a # v1.49.3
         with:
           args: --out dist
       - name: "Test wheel"
@@ -731,7 +747,7 @@ jobs:
       - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
         with:
           persist-credentials: false
-      - uses: astral-sh/setup-uv@445689ea25e0de0a23313031f5fe577c74ae45a1 # v6.3.0
+      - uses: astral-sh/setup-uv@bd01e18f51369d5a26f1651c3cb451d3417e3bba # v6.3.1
       - uses: Swatinem/rust-cache@9d47c6ad4b02e050fd481d890b2ea34778fd09d6 # v2.7.8
       - uses: actions/setup-node@49933ea5288caeca8642d1e84afbd3f7d6820020 # v4.4.0
         with:
@@ -774,7 +790,7 @@ jobs:
       - name: "Install Rust toolchain"
         run: rustup show
       - name: Install uv
-        uses: astral-sh/setup-uv@445689ea25e0de0a23313031f5fe577c74ae45a1 # v6.3.0
+        uses: astral-sh/setup-uv@bd01e18f51369d5a26f1651c3cb451d3417e3bba # v6.3.1
       - name: "Install Insiders dependencies"
         if: ${{ env.MKDOCS_INSIDERS_SSH_KEY_EXISTS == 'true' }}
         run: uv pip install -r docs/requirements-insiders.txt --system
@@ -906,7 +922,7 @@ jobs:
           persist-credentials: false
 
       - uses: Swatinem/rust-cache@9d47c6ad4b02e050fd481d890b2ea34778fd09d6 # v2.7.8
-      - uses: astral-sh/setup-uv@445689ea25e0de0a23313031f5fe577c74ae45a1 # v6.3.0
+      - uses: astral-sh/setup-uv@bd01e18f51369d5a26f1651c3cb451d3417e3bba # v6.3.1
 
       - name: "Install Rust toolchain"
         run: rustup show
@@ -939,7 +955,7 @@ jobs:
           persist-credentials: false
 
       - uses: Swatinem/rust-cache@9d47c6ad4b02e050fd481d890b2ea34778fd09d6 # v2.7.8
-      - uses: astral-sh/setup-uv@445689ea25e0de0a23313031f5fe577c74ae45a1 # v6.3.0
+      - uses: astral-sh/setup-uv@bd01e18f51369d5a26f1651c3cb451d3417e3bba # v6.3.1
 
       - name: "Install Rust toolchain"
         run: rustup show

.github/workflows/daily_fuzz.yaml

@@ -34,7 +34,7 @@ jobs:
       - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
         with:
           persist-credentials: false
-      - uses: astral-sh/setup-uv@445689ea25e0de0a23313031f5fe577c74ae45a1 # v6.3.0
+      - uses: astral-sh/setup-uv@bd01e18f51369d5a26f1651c3cb451d3417e3bba # v6.3.1
       - name: "Install Rust toolchain"
         run: rustup show
       - name: "Install mold"

.github/workflows/mypy_primer.yaml

@@ -37,7 +37,7 @@ jobs:
           persist-credentials: false
 
       - name: Install the latest version of uv
-        uses: astral-sh/setup-uv@445689ea25e0de0a23313031f5fe577c74ae45a1 # v6.3.0
+        uses: astral-sh/setup-uv@bd01e18f51369d5a26f1651c3cb451d3417e3bba # v6.3.1
 
       - uses: Swatinem/rust-cache@9d47c6ad4b02e050fd481d890b2ea34778fd09d6 # v2.7.8
         with:
@@ -48,6 +48,8 @@ jobs:
 
       - name: Run mypy_primer
         shell: bash
+        env:
+          TY_MEMORY_REPORT: mypy_primer
         run: |
           cd ruff
 

.github/workflows/publish-pypi.yml

@@ -22,7 +22,7 @@ jobs:
       id-token: write
     steps:
       - name: "Install uv"
-        uses: astral-sh/setup-uv@445689ea25e0de0a23313031f5fe577c74ae45a1 # v6.3.0
+        uses: astral-sh/setup-uv@bd01e18f51369d5a26f1651c3cb451d3417e3bba # v6.3.1
       - uses: actions/download-artifact@d3f86a106a0bac45b974a628896c90dbdf5c8093 # v4.3.0
         with:
           pattern: wheels-*

.github/workflows/setup-dev-drive.ps1

@@ -0,0 +1,93 @@
+# Configures a drive for testing in CI.
+#
+# When using standard GitHub Actions runners, a `D:` drive is present and has
+# similar or better performance characteristics than a ReFS dev drive. Sometimes
+# using a larger runner is still more performant (e.g., when running the test
+# suite) and we need to create a dev drive. This script automatically configures
+# the appropriate drive.
+#
+# When using GitHub Actions' "larger runners", the `D:` drive is not present and
+# we create a DevDrive mount on `C:`. This is purported to be more performant
+# than an ReFS drive, though we did not see a change when we switched over.
+#
+# When using Depot runners, the underling infrastructure is EC2, which does not
+# support Hyper-V. The `New-VHD` commandlet only works with Hyper-V, but we can
+# create a ReFS drive using `diskpart` and `format` directory. We cannot use a
+# DevDrive, as that also requires Hyper-V. The Depot runners use `D:` already,
+# so we must check if it's a Depot runner first, and we use `V:` as the target
+# instead.
+
+
+if ($env:DEPOT_RUNNER -eq "1") {
+    Write-Output "DEPOT_RUNNER detected, setting up custom dev drive..."
+
+    # Create VHD and configure drive using diskpart
+    $vhdPath = "C:\ruff_dev_drive.vhdx"
+    @"
+create vdisk file="$vhdPath" maximum=20480 type=expandable
+attach vdisk
+create partition primary
+active
+assign letter=V
+"@ | diskpart
+
+    # Format the drive as ReFS
+    format V: /fs:ReFS /q /y
+    $Drive = "V:"
+
+    Write-Output "Custom dev drive created at $Drive"
+} elseif (Test-Path "D:\") {
+	# Note `Get-PSDrive` is not sufficient because the drive letter is assigned.
+    Write-Output "Using existing drive at D:"
+    $Drive = "D:"
+} else {
+	# The size (20 GB) is chosen empirically to be large enough for our
+	# workflows; larger drives can take longer to set up.
+	$Volume = New-VHD -Path C:/ruff_dev_drive.vhdx -SizeBytes 20GB |
+						Mount-VHD -Passthru |
+						Initialize-Disk -Passthru |
+						New-Partition -AssignDriveLetter -UseMaximumSize |
+						Format-Volume -DevDrive -Confirm:$false -Force
+
+	$Drive = "$($Volume.DriveLetter):"
+
+	# Set the drive as trusted
+	# See https://learn.microsoft.com/en-us/windows/dev-drive/#how-do-i-designate-a-dev-drive-as-trusted
+	fsutil devdrv trust $Drive
+
+	# Disable antivirus filtering on dev drives
+	# See https://learn.microsoft.com/en-us/windows/dev-drive/#how-do-i-configure-additional-filters-on-dev-drive
+	fsutil devdrv enable /disallowAv
+
+	# Remount so the changes take effect
+	Dismount-VHD -Path C:/ruff_dev_drive.vhdx
+	Mount-VHD -Path C:/ruff_dev_drive.vhdx
+
+	# Show some debug information
+	Write-Output $Volume
+	fsutil devdrv query $Drive
+
+    Write-Output "Using Dev Drive at $Volume"
+}
+
+$Tmp = "$($Drive)\ruff-tmp"
+
+# Create the directory ahead of time in an attempt to avoid race-conditions
+New-Item $Tmp -ItemType Directory
+
+# Move Cargo to the dev drive
+New-Item -Path "$($Drive)/.cargo/bin" -ItemType Directory -Force
+if (Test-Path "C:/Users/runneradmin/.cargo") {
+    Copy-Item -Path "C:/Users/runneradmin/.cargo/*" -Destination "$($Drive)/.cargo/" -Recurse -Force
+}
+
+Write-Output `
+	"DEV_DRIVE=$($Drive)" `
+	"TMP=$($Tmp)" `
+	"TEMP=$($Tmp)" `
+	"UV_INTERNAL__TEST_DIR=$($Tmp)" `
+	"RUSTUP_HOME=$($Drive)/.rustup" `
+	"CARGO_HOME=$($Drive)/.cargo" `
+	"RUFF_WORKSPACE=$($Drive)/ruff" `
+	"PATH=$($Drive)/.cargo/bin;$env:PATH" `
+	>> $env:GITHUB_ENV

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

@@ -32,7 +32,7 @@ jobs:
           persist-credentials: false
 
       - name: Install the latest version of uv
-        uses: astral-sh/setup-uv@445689ea25e0de0a23313031f5fe577c74ae45a1 # v6.3.0
+        uses: astral-sh/setup-uv@bd01e18f51369d5a26f1651c3cb451d3417e3bba # v6.3.1
 
       - uses: Swatinem/rust-cache@9d47c6ad4b02e050fd481d890b2ea34778fd09d6 # v2.7.8
         with:

.pre-commit-config.yaml

@@ -81,7 +81,7 @@ repos:
         pass_filenames: false # This makes it a lot faster
 
   - repo: https://github.com/astral-sh/ruff-pre-commit
-    rev: v0.11.13
+    rev: v0.12.1
     hooks:
       - id: ruff-format
       - id: ruff
@@ -91,7 +91,7 @@ repos:
 
   # Prettier
   - repo: https://github.com/rbubley/mirrors-prettier
-    rev: v3.5.3
+    rev: v3.6.2
     hooks:
       - id: prettier
         types: [yaml]
@@ -99,12 +99,12 @@ repos:
   # zizmor detects security vulnerabilities in GitHub Actions workflows.
   # Additional configuration for the tool is found in `.github/zizmor.yml`
   - repo: https://github.com/woodruffw/zizmor-pre-commit
-    rev: v1.9.0
+    rev: v1.10.0
     hooks:
       - id: zizmor
 
   - repo: https://github.com/python-jsonschema/check-jsonschema
-    rev: 0.33.0
+    rev: 0.33.1
     hooks:
       - id: check-github-workflows
 

Cargo.lock

@@ -132,6 +132,15 @@ version = "1.0.98"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "e16d2d3311acee920a9eb8d33b8cbc1787ce4a264e85f964c2404b969bdcd487"
 
+[[package]]
+name = "approx"
+version = "0.5.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "cab112f0a86d568ea0e627cc1d6be74a1e9cd55214684db5561995f6dad897c6"
+dependencies = [
+ "num-traits",
+]
+
 [[package]]
 name = "arc-swap"
 version = "1.7.1"
@@ -169,6 +178,36 @@ dependencies = [
  "tempfile",
 ]
 
+[[package]]
+name = "attribute-derive"
+version = "0.10.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0053e96dd3bec5b4879c23a138d6ef26f2cb936c9cdc96274ac2b9ed44b5bb54"
+dependencies = [
+ "attribute-derive-macro",
+ "derive-where",
+ "manyhow",
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
+[[package]]
+name = "attribute-derive-macro"
+version = "0.10.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "463b53ad0fd5b460af4b1915fe045ff4d946d025fb6c4dc3337752eaa980f71b"
+dependencies = [
+ "collection_literals",
+ "interpolator",
+ "manyhow",
+ "proc-macro-utils",
+ "proc-macro2",
+ "quote",
+ "quote-use",
+ "syn",
+]
+
 [[package]]
 name = "autocfg"
 version = "1.4.0"
@@ -181,6 +220,15 @@ version = "0.13.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "9e1b586273c5702936fe7b7d6896644d8be71e6314cfe09d3167c95f712589e8"
 
+[[package]]
+name = "bincode"
+version = "1.3.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b1f45e9417d87227c7a56d22e471c6206462cba514c7590c09aff4cf6d1ddcad"
+dependencies = [
+ "serde",
+]
+
 [[package]]
 name = "bincode"
 version = "2.0.1"
@@ -419,9 +467,9 @@ checksum = "f46ad14479a25103f283c0f10005961cf086d8dc42205bb44c46ac563475dca6"
 
 [[package]]
 name = "clearscreen"
-version = "4.0.1"
+version = "4.0.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8c41dc435a7b98e4608224bbf65282309f5403719df9113621b30f8b6f74e2f4"
+checksum = "85a8ab73a1c02b0c15597b22e09c7dc36e63b2f601f9d1e83ac0c3decd38b1ae"
 dependencies = [
  "nix 0.29.0",
  "terminfo",
@@ -432,22 +480,27 @@ dependencies = [
 
 [[package]]
 name = "codspeed"
-version = "2.10.1"
+version = "3.0.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "93f4cce9c27c49c4f101fffeebb1826f41a9df2e7498b7cd4d95c0658b796c6c"
+checksum = "922018102595f6668cdd09c03f4bff2d951ce2318c6dca4fe11bdcb24b65b2bf"
 dependencies = [
+ "anyhow",
+ "bincode 1.3.3",
  "colored 2.2.0",
+ "glob",
  "libc",
+ "nix 0.29.0",
  "serde",
  "serde_json",
+ "statrs",
  "uuid",
 ]
 
 [[package]]
 name = "codspeed-criterion-compat"
-version = "2.10.1"
+version = "3.0.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c3c23d880a28a2aab52d38ca8481dd7a3187157d0a952196b6db1db3c8499725"
+checksum = "24d8ad82d2383cb74995f58993cbdd2914aed57b2f91f46580310dd81dc3d05a"
 dependencies = [
  "codspeed",
  "codspeed-criterion-compat-walltime",
@@ -456,9 +509,9 @@ dependencies = [
 
 [[package]]
 name = "codspeed-criterion-compat-walltime"
-version = "2.10.1"
+version = "3.0.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7b0a2f7365e347f4f22a67e9ea689bf7bc89900a354e22e26cf8a531a42c8fbb"
+checksum = "61badaa6c452d192a29f8387147888f0ab358553597c3fe9bf8a162ef7c2fa64"
 dependencies = [
  "anes",
  "cast",
@@ -481,9 +534,9 @@ dependencies = [
 
 [[package]]
 name = "codspeed-divan-compat"
-version = "2.10.1"
+version = "3.0.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8620a09dfaf37b3c45f982c4b65bd8f9b0203944da3ffa705c0fcae6b84655ff"
+checksum = "3acf1d6fe367c2ff5ff136ca723f678490c3691d59d7f2b83d5e53b7b25ac91e"
 dependencies = [
  "codspeed",
  "codspeed-divan-compat-macros",
@@ -492,9 +545,9 @@ dependencies = [
 
 [[package]]
 name = "codspeed-divan-compat-macros"
-version = "2.10.1"
+version = "3.0.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "30fe872bc4214626b35d3a1706a905d0243503bb6ba3bb7be2fc59083d5d680c"
+checksum = "bcfa2013d7bee54a497d0e1410751d5de690fd67a3e9eb728ca049b6a3d16d0b"
 dependencies = [
  "divan-macros",
  "itertools 0.14.0",
@@ -506,9 +559,9 @@ dependencies = [
 
 [[package]]
 name = "codspeed-divan-compat-walltime"
-version = "2.10.1"
+version = "3.0.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "104caa97b36d4092d89e24e4b103b40ede1edab03c0372d19e14a33f9393132b"
+checksum = "e513100fb0e7ba02fb3824546ecd2abfb8f334262f0972225b463aad07f99ff0"
 dependencies = [
  "cfg-if",
  "clap",
@@ -519,6 +572,12 @@ dependencies = [
  "regex-lite",
 ]
 
+[[package]]
+name = "collection_literals"
+version = "1.0.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "186dce98367766de751c42c4f03970fc60fc012296e706ccbb9d5df9b6c1e271"
+
 [[package]]
 name = "colorchoice"
 version = "1.0.3"
@@ -808,6 +867,17 @@ dependencies = [
  "parking_lot_core",
 ]
 
+[[package]]
+name = "derive-where"
+version = "1.5.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "510c292c8cf384b1a340b816a9a6cf2599eb8f566a44949024af88418000c50b"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
 [[package]]
 name = "diff"
 version = "0.1.13"
@@ -1067,6 +1137,29 @@ dependencies = [
  "version_check",
 ]
 
+[[package]]
+name = "get-size-derive2"
+version = "0.5.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1aac2af9f9a6a50e31b1e541d05b7925add83d3982c2793193fe9d4ee584323c"
+dependencies = [
+ "attribute-derive",
+ "quote",
+ "syn",
+]
+
+[[package]]
+name = "get-size2"
+version = "0.5.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "624a0312efd19e1c45922dfcc2d6806d3ffc4bca261f89f31fcc4f63f438d885"
+dependencies = [
+ "compact_str",
+ "get-size-derive2",
+ "hashbrown 0.15.4",
+ "smallvec",
+]
+
 [[package]]
 name = "getopts"
 version = "0.2.21"
@@ -1377,9 +1470,9 @@ dependencies = [
 
 [[package]]
 name = "indexmap"
-version = "2.9.0"
+version = "2.10.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "cea70ddb795996207ad57735b50c5982d8844f38ba9ee5f1aedcfb708a2aa11e"
+checksum = "fe4cd85333e22411419a0bcae1297d25e58c9443848b11dc6a86fefe8c78a661"
 dependencies = [
  "equivalent",
  "hashbrown 0.15.4",
@@ -1455,6 +1548,12 @@ dependencies = [
  "serde_json",
 ]
 
+[[package]]
+name = "interpolator"
+version = "0.5.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "71dd52191aae121e8611f1e8dc3e324dd0dd1dee1e6dd91d10ee07a3cfb4d9d8"
+
 [[package]]
 name = "intrusive-collections"
 version = "0.9.7"
@@ -1716,9 +1815,9 @@ checksum = "241eaef5fd12c88705a01fc1066c48c4b36e0dd4377dcdc7ec3942cea7a69956"
 
 [[package]]
 name = "lock_api"
-version = "0.4.12"
+version = "0.4.13"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "07af8b9cdd281b7915f413fa73f29ebd5d55d0d3f0155584dade1ff18cea1b17"
+checksum = "96936507f153605bddfcda068dd804796c84324ed2510809e5b2a624c81da765"
 dependencies = [
  "autocfg",
  "scopeguard",
@@ -1755,6 +1854,29 @@ dependencies = [
  "url",
 ]
 
+[[package]]
+name = "manyhow"
+version = "0.11.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b33efb3ca6d3b07393750d4030418d594ab1139cee518f0dc88db70fec873587"
+dependencies = [
+ "manyhow-macros",
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
+[[package]]
+name = "manyhow-macros"
+version = "0.11.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "46fce34d199b78b6e6073abf984c9cf5fd3e9330145a93ee0738a7443e371495"
+dependencies = [
+ "proc-macro-utils",
+ "proc-macro2",
+ "quote",
+]
+
 [[package]]
 name = "markdown"
 version = "1.0.0"
@@ -1981,9 +2103,9 @@ checksum = "04744f49eae99ab78e0d5c0b603ab218f515ea8cfe5a456d7629ad883a3b6e7d"
 
 [[package]]
 name = "ordermap"
-version = "0.5.7"
+version = "0.5.8"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7d31b8b7a99f71bdff4235faf9ce9eada0ad3562c8fbeb7d607d9f41a6ec569d"
+checksum = "6d6bff06e4a5dc6416bead102d3e63c480dd852ffbb278bf8cfeb4966b329609"
 dependencies = [
  "indexmap",
  "serde",
@@ -2014,6 +2136,16 @@ version = "0.1.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "b15813163c1d831bf4a13c3610c05c0d03b39feb07f7e09fa234dac9b15aaf39"
 
+[[package]]
+name = "papaya"
+version = "0.2.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f92dd0b07c53a0a0c764db2ace8c541dc47320dad97c2200c2a637ab9dd2328f"
+dependencies = [
+ "equivalent",
+ "seize",
+]
+
 [[package]]
 name = "parking_lot"
 version = "0.12.3"
@@ -2315,6 +2447,17 @@ dependencies = [
  "toml_edit",
 ]
 
+[[package]]
+name = "proc-macro-utils"
+version = "0.10.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "eeaf08a13de400bc215877b5bdc088f241b12eb42f0a548d3390dc1c56bb7071"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "smallvec",
+]
+
 [[package]]
 name = "proc-macro2"
 version = "1.0.95"
@@ -2391,6 +2534,28 @@ dependencies = [
  "proc-macro2",
 ]
 
+[[package]]
+name = "quote-use"
+version = "0.8.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9619db1197b497a36178cfc736dc96b271fe918875fbf1344c436a7e93d0321e"
+dependencies = [
+ "quote",
+ "quote-use-macros",
+]
+
+[[package]]
+name = "quote-use-macros"
+version = "0.8.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "82ebfb7faafadc06a7ab141a6f67bcfb24cb8beb158c6fe933f2f035afa99f35"
+dependencies = [
+ "proc-macro-utils",
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
 [[package]]
 name = "r-efi"
 version = "5.2.0"
@@ -2564,13 +2729,14 @@ dependencies = [
  "anyhow",
  "argfile",
  "assert_fs",
- "bincode",
+ "bincode 2.0.1",
  "bitflags 2.9.1",
  "cachedir",
  "clap",
  "clap_complete_command",
  "clearscreen",
  "colored 3.0.0",
+ "dunce",
  "filetime",
  "globwalk",
  "ignore",
@@ -2680,6 +2846,7 @@ dependencies = [
  "dunce",
  "etcetera",
  "filetime",
+ "get-size2",
  "glob",
  "ignore",
  "insta",
@@ -2795,6 +2962,7 @@ dependencies = [
 name = "ruff_index"
 version = "0.0.0"
 dependencies = [
+ "get-size2",
  "ruff_macros",
  "salsa",
  "static_assertions",
@@ -2812,6 +2980,7 @@ dependencies = [
  "fern",
  "glob",
  "globset",
+ "hashbrown 0.15.4",
  "imperative",
  "insta",
  "is-macro",
@@ -2907,6 +3076,7 @@ dependencies = [
  "aho-corasick",
  "bitflags 2.9.1",
  "compact_str",
+ "get-size2",
  "is-macro",
  "itertools 0.14.0",
  "memchr",
@@ -3006,6 +3176,7 @@ dependencies = [
  "bitflags 2.9.1",
  "bstr",
  "compact_str",
+ "get-size2",
  "insta",
  "memchr",
  "ruff_annotate_snippets",
@@ -3112,6 +3283,7 @@ dependencies = [
 name = "ruff_source_file"
 version = "0.0.0"
 dependencies = [
+ "get-size2",
  "memchr",
  "ruff_text_size",
  "serde",
@@ -3121,6 +3293,7 @@ dependencies = [
 name = "ruff_text_size"
 version = "0.0.0"
 dependencies = [
+ "get-size2",
  "schemars",
  "serde",
  "serde_test",
@@ -3248,8 +3421,8 @@ checksum = "28d3b2b1366ec20994f1fd18c3c594f05c5dd4bc44d8bb0c1c632c8d6829481f"
 
 [[package]]
 name = "salsa"
-version = "0.22.0"
-source = "git+https://github.com/salsa-rs/salsa.git?rev=09627e450566f894956710a3fd923dc80462ae6d#09627e450566f894956710a3fd923dc80462ae6d"
+version = "0.23.0"
+source = "git+https://github.com/salsa-rs/salsa?rev=fc00eba89e5dcaa5edba51c41aa5f309b5cb126b#fc00eba89e5dcaa5edba51c41aa5f309b5cb126b"
 dependencies = [
  "boxcar",
  "compact_str",
@@ -3259,6 +3432,7 @@ dependencies = [
  "hashlink",
  "indexmap",
  "intrusive-collections",
+ "papaya",
  "parking_lot",
  "portable-atomic",
  "rayon",
@@ -3272,13 +3446,13 @@ dependencies = [
 
 [[package]]
 name = "salsa-macro-rules"
-version = "0.22.0"
-source = "git+https://github.com/salsa-rs/salsa.git?rev=09627e450566f894956710a3fd923dc80462ae6d#09627e450566f894956710a3fd923dc80462ae6d"
+version = "0.23.0"
+source = "git+https://github.com/salsa-rs/salsa?rev=fc00eba89e5dcaa5edba51c41aa5f309b5cb126b#fc00eba89e5dcaa5edba51c41aa5f309b5cb126b"
 
 [[package]]
 name = "salsa-macros"
-version = "0.22.0"
-source = "git+https://github.com/salsa-rs/salsa.git?rev=09627e450566f894956710a3fd923dc80462ae6d#09627e450566f894956710a3fd923dc80462ae6d"
+version = "0.23.0"
+source = "git+https://github.com/salsa-rs/salsa?rev=fc00eba89e5dcaa5edba51c41aa5f309b5cb126b#fc00eba89e5dcaa5edba51c41aa5f309b5cb126b"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -3331,6 +3505,16 @@ version = "4.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "1c107b6f4780854c8b126e228ea8869f4d7b71260f962fefb57b996b8959ba6b"
 
+[[package]]
+name = "seize"
+version = "0.5.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e4b8d813387d566f627f3ea1b914c068aac94c40ae27ec43f5f33bde65abefe7"
+dependencies = [
+ "libc",
+ "windows-sys 0.52.0",
+]
+
 [[package]]
 name = "serde"
 version = "1.0.219"
@@ -3531,6 +3715,16 @@ version = "1.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "a2eb9349b6444b326872e140eb1cf5e7c522154d69e7a0ffb0fb81c06b37543f"
 
+[[package]]
+name = "statrs"
+version = "0.18.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2a3fe7c28c6512e766b0874335db33c94ad7b8f9054228ae1c2abd47ce7d335e"
+dependencies = [
+ "approx",
+ "num-traits",
+]
+
 [[package]]
 name = "strip-ansi-escapes"
 version = "0.2.1"
@@ -3991,6 +4185,7 @@ dependencies = [
  "camino",
  "colored 3.0.0",
  "crossbeam",
+ "get-size2",
  "globset",
  "insta",
  "notify",
@@ -4030,6 +4225,7 @@ dependencies = [
  "countme",
  "dir-test",
  "drop_bomb",
+ "get-size2",
  "glob",
  "hashbrown 0.15.4",
  "indexmap",
@@ -4091,6 +4287,7 @@ dependencies = [
  "ty_ide",
  "ty_project",
  "ty_python_semantic",
+ "ty_vendored",
 ]
 
 [[package]]
@@ -4130,6 +4327,7 @@ version = "0.0.0"
 dependencies = [
  "path-slash",
  "ruff_db",
+ "static_assertions",
  "walkdir",
  "zip",
 ]
@@ -4564,11 +4762,10 @@ dependencies = [
 
 [[package]]
 name = "which"
-version = "7.0.3"
+version = "8.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "24d643ce3fd3e5b54854602a080f34fb10ab75e0b813ee32d00ca2b44fa74762"
+checksum = "d3fabb953106c3c8eea8306e4393700d7657561cb43122571b172bbfb7c7ba1d"
 dependencies = [
- "either",
  "env_home",
  "rustix",
  "winsafe",

Cargo.toml

@@ -5,7 +5,7 @@ resolver = "2"
 [workspace.package]
 # Please update rustfmt.toml when bumping the Rust edition
 edition = "2024"
-rust-version = "1.85"
+rust-version = "1.86"
 homepage = "https://docs.astral.sh/ruff"
 documentation = "https://docs.astral.sh/ruff"
 repository = "https://github.com/astral-sh/ruff"
@@ -62,8 +62,8 @@ camino = { version = "1.1.7" }
 clap = { version = "4.5.3", features = ["derive"] }
 clap_complete_command = { version = "0.6.0" }
 clearscreen = { version = "4.0.0" }
-divan = { package = "codspeed-divan-compat", version = "2.10.1" }
-codspeed-criterion-compat = { version = "2.6.0", default-features = false }
+divan = { package = "codspeed-divan-compat", version = "3.0.2" }
+codspeed-criterion-compat = { version = "3.0.2", default-features = false }
 colored = { version = "3.0.0" }
 console_error_panic_hook = { version = "0.1.7" }
 console_log = { version = "1.0.0" }
@@ -79,6 +79,12 @@ etcetera = { version = "0.10.0" }
 fern = { version = "0.7.0" }
 filetime = { version = "0.2.23" }
 getrandom = { version = "0.3.1" }
+get-size2 = { version = "0.5.0", features = [
+    "derive",
+    "smallvec",
+    "hashbrown",
+    "compact-str"
+] }
 glob = { version = "0.3.1" }
 globset = { version = "0.4.14" }
 globwalk = { version = "0.9.1" }
@@ -131,7 +137,7 @@ 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 = "09627e450566f894956710a3fd923dc80462ae6d" }
+salsa = { git = "https://github.com/salsa-rs/salsa", rev = "fc00eba89e5dcaa5edba51c41aa5f309b5cb126b" }
 schemars = { version = "0.8.16" }
 seahash = { version = "4.1.0" }
 serde = { version = "1.0.197", features = ["derive"] }
@@ -221,6 +227,7 @@ unnecessary_debug_formatting = "allow"  # too many instances, the display also d
 # Without the hashes we run into a `rustfmt` bug in some snapshot tests, see #13250
 needless_raw_string_hashes = "allow"
 # Disallowed restriction lints
+ignore_without_reason = "allow" # Too many exsisting instances, and there's no auto fix.
 print_stdout = "warn"
 print_stderr = "warn"
 dbg_macro = "warn"

README.md

@@ -423,6 +423,7 @@ Ruff is used by a number of major open-source projects and companies, including:
 
 - [Albumentations](https://github.com/albumentations-team/albumentations)
 - Amazon ([AWS SAM](https://github.com/aws/serverless-application-model))
+- [Anki](https://apps.ankiweb.net/)
 - Anthropic ([Python SDK](https://github.com/anthropics/anthropic-sdk-python))
 - [Apache Airflow](https://github.com/apache/airflow)
 - AstraZeneca ([Magnus](https://github.com/AstraZeneca/magnus-core))

crates/ruff/Cargo.toml

@@ -68,6 +68,7 @@ ruff_linter = { workspace = true, features = ["clap", "test-rules"] }
 assert_fs = { workspace = true }
 # Avoid writing colored snapshots when running tests from the terminal
 colored = { workspace = true, features = ["no-color"] }
+dunce = { workspace = true }
 indoc = { workspace = true }
 insta = { workspace = true, features = ["filters", "json"] }
 insta-cmd = { workspace = true }

crates/ruff/src/printer.rs

@@ -6,7 +6,6 @@ use anyhow::Result;
 use bitflags::bitflags;
 use colored::Colorize;
 use itertools::{Itertools, iterate};
-use ruff_linter::codes::NoqaCode;
 use ruff_linter::linter::FixTable;
 use serde::Serialize;
 
@@ -15,7 +14,7 @@ use ruff_linter::logging::LogLevel;
 use ruff_linter::message::{
     AzureEmitter, Emitter, EmitterContext, GithubEmitter, GitlabEmitter, GroupedEmitter,
     JsonEmitter, JsonLinesEmitter, JunitEmitter, OldDiagnostic, PylintEmitter, RdjsonEmitter,
-    SarifEmitter, TextEmitter,
+    SarifEmitter, SecondaryCode, TextEmitter,
 };
 use ruff_linter::notify_user;
 use ruff_linter::settings::flags::{self};
@@ -36,8 +35,8 @@ bitflags! {
 }
 
 #[derive(Serialize)]
-struct ExpandedStatistics {
-    code: Option<NoqaCode>,
+struct ExpandedStatistics<'a> {
+    code: Option<&'a SecondaryCode>,
     name: &'static str,
     count: usize,
     fixable: bool,
@@ -303,11 +302,12 @@ impl Printer {
         let statistics: Vec<ExpandedStatistics> = diagnostics
             .inner
             .iter()
-            .map(|message| (message.noqa_code(), message))
+            .map(|message| (message.secondary_code(), message))
             .sorted_by_key(|(code, message)| (*code, message.fixable()))
             .fold(
                 vec![],
-                |mut acc: Vec<((Option<NoqaCode>, &OldDiagnostic), usize)>, (code, message)| {
+                |mut acc: Vec<((Option<&SecondaryCode>, &OldDiagnostic), usize)>,
+                 (code, message)| {
                     if let Some(((prev_code, _prev_message), count)) = acc.last_mut() {
                         if *prev_code == code {
                             *count += 1;
@@ -349,12 +349,7 @@ impl Printer {
                 );
                 let code_width = statistics
                     .iter()
-                    .map(|statistic| {
-                        statistic
-                            .code
-                            .map_or_else(String::new, |rule| rule.to_string())
-                            .len()
-                    })
+                    .map(|statistic| statistic.code.map_or(0, |s| s.len()))
                     .max()
                     .unwrap();
                 let any_fixable = statistics.iter().any(|statistic| statistic.fixable);
@@ -370,7 +365,8 @@ impl Printer {
                         statistic.count.to_string().bold(),
                         statistic
                             .code
-                            .map_or_else(String::new, |rule| rule.to_string())
+                            .map(SecondaryCode::as_str)
+                            .unwrap_or_default()
                             .red()
                             .bold(),
                         if any_fixable {

crates/ruff/tests/lint.rs

@@ -612,7 +612,7 @@ fn extend_passed_via_config_argument() {
 #[test]
 fn nonexistent_extend_file() -> Result<()> {
     let tempdir = TempDir::new()?;
-    let project_dir = tempdir.path().canonicalize()?;
+    let project_dir = dunce::canonicalize(tempdir.path())?;
     fs::write(
         project_dir.join("ruff.toml"),
         r#"
@@ -653,7 +653,7 @@ extend = "ruff3.toml"
 #[test]
 fn circular_extend() -> Result<()> {
     let tempdir = TempDir::new()?;
-    let project_path = tempdir.path().canonicalize()?;
+    let project_path = dunce::canonicalize(tempdir.path())?;
 
     fs::write(
         project_path.join("ruff.toml"),
@@ -698,7 +698,7 @@ extend = "ruff.toml"
 #[test]
 fn parse_error_extends() -> Result<()> {
     let tempdir = TempDir::new()?;
-    let project_path = tempdir.path().canonicalize()?;
+    let project_path = dunce::canonicalize(tempdir.path())?;
 
     fs::write(
         project_path.join("ruff.toml"),
@@ -2130,7 +2130,7 @@ select = ["UP006"]
 #[test]
 fn requires_python_no_tool() -> Result<()> {
     let tempdir = TempDir::new()?;
-    let project_dir = tempdir.path().canonicalize()?;
+    let project_dir = dunce::canonicalize(tempdir.path())?;
     let ruff_toml = tempdir.path().join("pyproject.toml");
     fs::write(
         &ruff_toml,
@@ -2441,7 +2441,7 @@ requires-python = ">= 3.11"
 #[test]
 fn requires_python_no_tool_target_version_override() -> Result<()> {
     let tempdir = TempDir::new()?;
-    let project_dir = tempdir.path().canonicalize()?;
+    let project_dir = dunce::canonicalize(tempdir.path())?;
     let ruff_toml = tempdir.path().join("pyproject.toml");
     fs::write(
         &ruff_toml,
@@ -2752,7 +2752,7 @@ requires-python = ">= 3.11"
 #[test]
 fn requires_python_no_tool_with_check() -> Result<()> {
     let tempdir = TempDir::new()?;
-    let project_dir = tempdir.path().canonicalize()?;
+    let project_dir = dunce::canonicalize(tempdir.path())?;
     let ruff_toml = tempdir.path().join("pyproject.toml");
     fs::write(
         &ruff_toml,
@@ -2797,7 +2797,7 @@ requires-python = ">= 3.11"
 #[test]
 fn requires_python_ruff_toml_no_target_fallback() -> Result<()> {
     let tempdir = TempDir::new()?;
-    let project_dir = tempdir.path().canonicalize()?;
+    let project_dir = dunce::canonicalize(tempdir.path())?;
     let ruff_toml = tempdir.path().join("ruff.toml");
     fs::write(
         &ruff_toml,
@@ -3118,7 +3118,7 @@ from typing import Union;foo: Union[int, str] = 1
 #[test]
 fn requires_python_ruff_toml_no_target_fallback_check() -> Result<()> {
     let tempdir = TempDir::new()?;
-    let project_dir = tempdir.path().canonicalize()?;
+    let project_dir = dunce::canonicalize(tempdir.path())?;
     let ruff_toml = tempdir.path().join("ruff.toml");
     fs::write(
         &ruff_toml,
@@ -3173,7 +3173,7 @@ from typing import Union;foo: Union[int, str] = 1
 #[test]
 fn requires_python_pyproject_toml_above() -> Result<()> {
     let tempdir = TempDir::new()?;
-    let project_dir = tempdir.path().canonicalize()?;
+    let project_dir = dunce::canonicalize(tempdir.path())?;
     let outer_pyproject = tempdir.path().join("pyproject.toml");
     fs::write(
         &outer_pyproject,
@@ -3200,7 +3200,7 @@ from typing import Union;foo: Union[int, str] = 1
 "#,
     )?;
 
-    let testpy_canon = testpy.canonicalize()?;
+    let testpy_canon = dunce::canonicalize(testpy)?;
 
     insta::with_settings!({
         filters => vec![(tempdir_filter(&testpy_canon).as_str(), "[TMP]/foo/test.py"),(tempdir_filter(&project_dir).as_str(), "[TMP]/"),(r"(?m)^foo\\test","foo/test")]
@@ -3499,7 +3499,7 @@ from typing import Union;foo: Union[int, str] = 1
 #[test]
 fn requires_python_pyproject_toml_above_with_tool() -> Result<()> {
     let tempdir = TempDir::new()?;
-    let project_dir = tempdir.path().canonicalize()?;
+    let project_dir = dunce::canonicalize(tempdir.path())?;
     let outer_pyproject = tempdir.path().join("pyproject.toml");
     fs::write(
         &outer_pyproject,
@@ -3528,7 +3528,7 @@ from typing import Union;foo: Union[int, str] = 1
 "#,
     )?;
 
-    let testpy_canon = testpy.canonicalize()?;
+    let testpy_canon = dunce::canonicalize(testpy)?;
 
     insta::with_settings!({
         filters => vec![(tempdir_filter(&testpy_canon).as_str(), "[TMP]/foo/test.py"),(tempdir_filter(&project_dir).as_str(), "[TMP]/"),(r"foo\\","foo/")]
@@ -3827,7 +3827,7 @@ from typing import Union;foo: Union[int, str] = 1
 #[test]
 fn requires_python_ruff_toml_above() -> Result<()> {
     let tempdir = TempDir::new()?;
-    let project_dir = tempdir.path().canonicalize()?;
+    let project_dir = dunce::canonicalize(tempdir.path())?;
     let ruff_toml = tempdir.path().join("ruff.toml");
     fs::write(
         &ruff_toml,
@@ -3856,7 +3856,7 @@ from typing import Union;foo: Union[int, str] = 1
 "#,
     )?;
 
-    let testpy_canon = testpy.canonicalize()?;
+    let testpy_canon = dunce::canonicalize(testpy)?;
 
     insta::with_settings!({
         filters => vec![(tempdir_filter(&testpy_canon).as_str(), "[TMP]/foo/test.py"),(tempdir_filter(&project_dir).as_str(), "[TMP]/")]
@@ -4441,7 +4441,7 @@ from typing import Union;foo: Union[int, str] = 1
 #[test]
 fn requires_python_extend_from_shared_config() -> Result<()> {
     let tempdir = TempDir::new()?;
-    let project_dir = tempdir.path().canonicalize()?;
+    let project_dir = dunce::canonicalize(tempdir.path())?;
     let ruff_toml = tempdir.path().join("ruff.toml");
     fs::write(
         &ruff_toml,
@@ -4479,7 +4479,7 @@ from typing import Union;foo: Union[int, str] = 1
 "#,
     )?;
 
-    let testpy_canon = testpy.canonicalize()?;
+    let testpy_canon = dunce::canonicalize(testpy)?;
 
     insta::with_settings!({
         filters => vec![(tempdir_filter(&testpy_canon).as_str(), "[TMP]/test.py"),(tempdir_filter(&project_dir).as_str(), "[TMP]/")]

crates/ruff/tests/show_settings.rs

@@ -12,10 +12,8 @@ fn display_default_settings() -> anyhow::Result<()> {
 
     // Tempdir path's on macos are symlinks, which doesn't play nicely with
     // our snapshot filtering.
-    let project_dir = tempdir
-        .path()
-        .canonicalize()
-        .context("Failed to canonical tempdir path.")?;
+    let project_dir =
+        dunce::canonicalize(tempdir.path()).context("Failed to canonical tempdir path.")?;
 
     std::fs::write(
         project_dir.join("pyproject.toml"),

crates/ruff_annotate_snippets/src/renderer/display_list.rs

@@ -821,11 +821,7 @@ impl DisplaySourceAnnotation<'_> {
     // Length of this annotation as displayed in the stderr output
     fn len(&self) -> usize {
         // Account for usize underflows
-        if self.range.1 > self.range.0 {
-            self.range.1 - self.range.0
-        } else {
-            self.range.0 - self.range.1
-        }
+        self.range.1.abs_diff(self.range.0)
     }
 
     fn takes_space(&self) -> bool {

crates/ruff_benchmark/benches/ty.rs

@@ -348,10 +348,10 @@ fn benchmark_many_tuple_assignments(criterion: &mut Criterion) {
     });
 }
 
-fn benchmark_many_attribute_assignments(criterion: &mut Criterion) {
+fn benchmark_complex_constrained_attributes_1(criterion: &mut Criterion) {
     setup_rayon();
 
-    criterion.bench_function("ty_micro[many_attribute_assignments]", |b| {
+    criterion.bench_function("ty_micro[complex_constrained_attributes_1]", |b| {
         b.iter_batched_ref(
             || {
                 // This is a regression benchmark for https://github.com/astral-sh/ty/issues/627.
@@ -400,6 +400,47 @@ fn benchmark_many_attribute_assignments(criterion: &mut Criterion) {
     });
 }
 
+fn benchmark_complex_constrained_attributes_2(criterion: &mut Criterion) {
+    setup_rayon();
+
+    criterion.bench_function("ty_micro[complex_constrained_attributes_2]", |b| {
+        b.iter_batched_ref(
+            || {
+                // This is is similar to the case above, but now the attributes are actually defined.
+                // https://github.com/astral-sh/ty/issues/711
+                setup_micro_case(
+                    r#"
+                    class C:
+                        def f(self: "C"):
+                            self.a = ""
+                            self.b = ""
+
+                            if isinstance(self.a, str):
+                                return
+
+                            if isinstance(self.b, str):
+                                return
+                            if isinstance(self.b, str):
+                                return
+                            if isinstance(self.b, str):
+                                return
+                            if isinstance(self.b, str):
+                                return
+                            if isinstance(self.b, str):
+                                return
+                    "#,
+                )
+            },
+            |case| {
+                let Case { db, .. } = case;
+                let result = db.check();
+                assert_eq!(result.len(), 0);
+            },
+            BatchSize::SmallInput,
+        );
+    });
+}
+
 struct ProjectBenchmark<'a> {
     project: InstalledProject<'a>,
     fs: MemoryFileSystem,
@@ -534,7 +575,8 @@ criterion_group!(
     micro,
     benchmark_many_string_assignments,
     benchmark_many_tuple_assignments,
-    benchmark_many_attribute_assignments,
+    benchmark_complex_constrained_attributes_1,
+    benchmark_complex_constrained_attributes_2,
 );
 criterion_group!(project, anyio, attrs, hydra);
 criterion_main!(check_file, micro, project);

crates/ruff_db/Cargo.toml

@@ -14,10 +14,10 @@ license = { workspace = true }
 ruff_annotate_snippets = { workspace = true }
 ruff_cache = { workspace = true, optional = true }
 ruff_notebook = { workspace = true }
-ruff_python_ast = { workspace = true }
+ruff_python_ast = { workspace = true, features = ["get-size"] }
 ruff_python_parser = { workspace = true }
 ruff_python_trivia = { workspace = true }
-ruff_source_file = { workspace = true }
+ruff_source_file = { workspace = true, features = ["get-size"] }
 ruff_text_size = { workspace = true }
 
 anstyle = { workspace = true }
@@ -27,6 +27,7 @@ countme = { workspace = true }
 dashmap = { workspace = true }
 dunce = { workspace = true }
 filetime = { workspace = true }
+get-size2 = { workspace = true }
 glob = { workspace = true }
 ignore = { workspace = true, optional = true }
 matchit = { workspace = true }

crates/ruff_db/src/diagnostic/mod.rs

@@ -19,7 +19,7 @@ mod stylesheet;
 /// characteristics in the inputs given to the tool. Typically, but not always,
 /// a characteristic is a deficiency. An example of a characteristic that is
 /// _not_ a deficiency is the `reveal_type` diagnostic for our type checker.
-#[derive(Debug, Clone, Eq, PartialEq)]
+#[derive(Debug, Clone, Eq, PartialEq, get_size2::GetSize)]
 pub struct Diagnostic {
     /// The actual diagnostic.
     ///
@@ -270,7 +270,7 @@ impl Diagnostic {
     }
 }
 
-#[derive(Debug, Clone, Eq, PartialEq)]
+#[derive(Debug, Clone, Eq, PartialEq, get_size2::GetSize)]
 struct DiagnosticInner {
     id: DiagnosticId,
     severity: Severity,
@@ -342,7 +342,7 @@ impl Eq for RenderingSortKey<'_> {}
 /// Currently, the order in which sub-diagnostics are rendered relative to one
 /// another (for a single parent diagnostic) is the order in which they were
 /// attached to the diagnostic.
-#[derive(Debug, Clone, Eq, PartialEq)]
+#[derive(Debug, Clone, Eq, PartialEq, get_size2::GetSize)]
 pub struct SubDiagnostic {
     /// Like with `Diagnostic`, we box the `SubDiagnostic` to make it
     /// pointer-sized.
@@ -443,7 +443,7 @@ impl SubDiagnostic {
     }
 }
 
-#[derive(Debug, Clone, Eq, PartialEq)]
+#[derive(Debug, Clone, Eq, PartialEq, get_size2::GetSize)]
 struct SubDiagnosticInner {
     severity: Severity,
     message: DiagnosticMessage,
@@ -471,7 +471,7 @@ struct SubDiagnosticInner {
 ///
 /// Messages attached to annotations should also be as brief and specific as
 /// possible. Long messages could negative impact the quality of rendering.
-#[derive(Debug, Clone, Eq, PartialEq)]
+#[derive(Debug, Clone, Eq, PartialEq, get_size2::GetSize)]
 pub struct Annotation {
     /// The span of this annotation, corresponding to some subsequence of the
     /// user's input that we want to highlight.
@@ -591,7 +591,7 @@ impl Annotation {
 ///
 /// These tags are used to provide additional information about the annotation.
 /// and are passed through to the language server protocol.
-#[derive(Debug, Clone, Eq, PartialEq)]
+#[derive(Debug, Clone, Eq, PartialEq, get_size2::GetSize)]
 pub enum DiagnosticTag {
     /// Unused or unnecessary code. Used for unused parameters, unreachable code, etc.
     Unnecessary,
@@ -605,7 +605,7 @@ pub enum DiagnosticTag {
 /// be in kebab case, e.g. `no-foo` (all lower case).
 ///
 /// Rules use kebab case, e.g. `no-foo`.
-#[derive(Debug, Copy, Clone, PartialOrd, Ord, PartialEq, Eq, Hash)]
+#[derive(Debug, Copy, Clone, PartialOrd, Ord, PartialEq, Eq, Hash, get_size2::GetSize)]
 pub struct LintName(&'static str);
 
 impl LintName {
@@ -645,7 +645,7 @@ impl PartialEq<&str> for LintName {
 }
 
 /// Uniquely identifies the kind of a diagnostic.
-#[derive(Debug, Copy, Clone, Eq, PartialEq, PartialOrd, Ord, Hash)]
+#[derive(Debug, Copy, Clone, Eq, PartialEq, PartialOrd, Ord, Hash, get_size2::GetSize)]
 pub enum DiagnosticId {
     Panic,
 
@@ -800,7 +800,7 @@ impl std::fmt::Display for DiagnosticId {
 ///
 /// This enum presents a unified interface to these two types for the sake of creating [`Span`]s and
 /// emitting diagnostics from both ty and ruff.
-#[derive(Debug, Clone, PartialEq, Eq)]
+#[derive(Debug, Clone, PartialEq, Eq, get_size2::GetSize)]
 pub enum UnifiedFile {
     Ty(File),
     Ruff(SourceFile),
@@ -852,7 +852,7 @@ impl DiagnosticSource {
 /// It consists of a `File` and an optional range into that file. When the
 /// range isn't present, it semantically implies that the diagnostic refers to
 /// the entire file. For example, when the file should be executable but isn't.
-#[derive(Debug, Clone, PartialEq, Eq)]
+#[derive(Debug, Clone, PartialEq, Eq, get_size2::GetSize)]
 pub struct Span {
     file: UnifiedFile,
     range: Option<TextRange>,
@@ -924,7 +924,7 @@ impl From<crate::files::FileRange> for Span {
     }
 }
 
-#[derive(Debug, Clone, Copy, PartialEq, Eq, Ord, PartialOrd)]
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Ord, PartialOrd, get_size2::GetSize)]
 pub enum Severity {
     Info,
     Warning,
@@ -1087,7 +1087,7 @@ impl std::fmt::Display for ConciseMessage<'_> {
 /// In most cases, callers shouldn't need to use this. Instead, there is
 /// a blanket trait implementation for `IntoDiagnosticMessage` for
 /// anything that implements `std::fmt::Display`.
-#[derive(Clone, Debug, Eq, PartialEq)]
+#[derive(Clone, Debug, Eq, PartialEq, get_size2::GetSize)]
 pub struct DiagnosticMessage(Box<str>);
 
 impl DiagnosticMessage {

crates/ruff_db/src/diagnostic/render.rs

@@ -637,6 +637,22 @@ pub trait FileResolver {
     fn input(&self, file: File) -> Input;
 }
 
+impl<T> FileResolver for T
+where
+    T: Db,
+{
+    fn path(&self, file: File) -> &str {
+        relativize_path(self.system().current_directory(), file.path(self).as_str())
+    }
+
+    fn input(&self, file: File) -> Input {
+        Input {
+            text: source_text(self, file),
+            line_index: line_index(self, file),
+        }
+    }
+}
+
 impl FileResolver for &dyn Db {
     fn path(&self, file: File) -> &str {
         relativize_path(self.system().current_directory(), file.path(*self).as_str())
@@ -708,7 +724,6 @@ fn relativize_path<'p>(cwd: &SystemPath, path: &'p str) -> &'p str {
 #[cfg(test)]
 mod tests {
 
-    use crate::Upcast;
     use crate::diagnostic::{Annotation, DiagnosticId, Severity, Span};
     use crate::files::system_path_to_file;
     use crate::system::{DbWithWritableSystem, SystemPath};
@@ -2221,7 +2236,7 @@ watermelon
         ///
         /// (This will set the "printed" flag on `Diagnostic`.)
         fn render(&self, diag: &Diagnostic) -> String {
-            diag.display(&self.db.upcast(), &self.config).to_string()
+            diag.display(&self.db, &self.config).to_string()
         }
     }
 

crates/ruff_db/src/files.rs

@@ -263,12 +263,23 @@ impl Files {
 
 impl fmt::Debug for Files {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-        let mut map = f.debug_map();
+        if f.alternate() {
+            let mut map = f.debug_map();
 
-        for entry in self.inner.system_by_path.iter() {
-            map.entry(entry.key(), entry.value());
+            for entry in self.inner.system_by_path.iter() {
+                map.entry(entry.key(), entry.value());
+            }
+            map.finish()
+        } else {
+            f.debug_struct("Files")
+                .field("system_by_path", &self.inner.system_by_path.len())
+                .field(
+                    "system_virtual_by_path",
+                    &self.inner.system_virtual_by_path.len(),
+                )
+                .field("vendored_by_path", &self.inner.vendored_by_path.len())
+                .finish()
         }
-        map.finish()
     }
 }
 
@@ -308,6 +319,9 @@ pub struct File {
     count: Count<File>,
 }
 
+// The Salsa heap is tracked separately.
+impl get_size2::GetSize for File {}
+
 impl File {
     /// Reads the content of the file into a [`String`].
     ///

crates/ruff_db/src/lib.rs

@@ -36,12 +36,6 @@ pub trait Db: salsa::Database {
     fn python_version(&self) -> PythonVersion;
 }
 
-/// Trait for upcasting a reference to a base trait object.
-pub trait Upcast<T: ?Sized> {
-    fn upcast(&self) -> &T;
-    fn upcast_mut(&mut self) -> &mut T;
-}
-
 /// Returns the maximum number of tasks that ty is allowed
 /// to process in parallel.
 ///
@@ -76,11 +70,11 @@ pub trait RustDoc {
 mod tests {
     use std::sync::{Arc, Mutex};
 
+    use crate::Db;
     use crate::files::Files;
     use crate::system::TestSystem;
     use crate::system::{DbWithTestSystem, System};
     use crate::vendored::VendoredFileSystem;
-    use crate::{Db, Upcast};
 
     type Events = Arc<Mutex<Vec<salsa::Event>>>;
 
@@ -153,15 +147,6 @@ mod tests {
         }
     }
 
-    impl Upcast<dyn Db> for TestDb {
-        fn upcast(&self) -> &(dyn Db + 'static) {
-            self
-        }
-        fn upcast_mut(&mut self) -> &mut (dyn Db + 'static) {
-            self
-        }
-    }
-
     impl DbWithTestSystem for TestDb {
         fn test_system(&self) -> &TestSystem {
             &self.system

crates/ruff_db/src/parsed.rs

@@ -2,6 +2,7 @@ use std::fmt::Formatter;
 use std::sync::Arc;
 
 use arc_swap::ArcSwapOption;
+use get_size2::GetSize;
 use ruff_python_ast::{AnyRootNodeRef, ModModule, NodeIndex};
 use ruff_python_parser::{ParseOptions, Parsed, parse_unchecked};
 
@@ -20,7 +21,7 @@ use crate::source::source_text;
 /// reflected in the changed AST offsets.
 /// The other reason is that Ruff's AST doesn't implement `Eq` which Salsa requires
 /// for determining if a query result is unchanged.
-#[salsa::tracked(returns(ref), no_eq)]
+#[salsa::tracked(returns(ref), no_eq, heap_size=get_size2::GetSize::get_heap_size)]
 pub fn parsed_module(db: &dyn Db, file: File) -> ParsedModule {
     let _span = tracing::trace_span!("parsed_module", ?file).entered();
 
@@ -44,9 +45,10 @@ pub fn parsed_module_impl(db: &dyn Db, file: File) -> Parsed<ModModule> {
 ///
 /// This type manages instances of the module AST. A particular instance of the AST
 /// is represented with the [`ParsedModuleRef`] type.
-#[derive(Clone)]
+#[derive(Clone, get_size2::GetSize)]
 pub struct ParsedModule {
     file: File,
+    #[get_size(size_fn = arc_swap_size)]
     inner: Arc<ArcSwapOption<indexed::IndexedModule>>,
 }
 
@@ -142,6 +144,18 @@ impl std::ops::Deref for ParsedModuleRef {
     }
 }
 
+/// Returns the heap-size of the currently stored `T` in the `ArcSwap`.
+fn arc_swap_size<T>(arc_swap: &Arc<ArcSwapOption<T>>) -> usize
+where
+    T: GetSize,
+{
+    if let Some(value) = &*arc_swap.load() {
+        T::get_heap_size(value)
+    } else {
+        0
+    }
+}
+
 mod indexed {
     use std::sync::Arc;
 
@@ -150,7 +164,7 @@ mod indexed {
     use ruff_python_parser::Parsed;
 
     /// A wrapper around the AST that allows access to AST nodes by index.
-    #[derive(Debug)]
+    #[derive(Debug, get_size2::GetSize)]
     pub struct IndexedModule {
         index: Box<[AnyRootNodeRef<'static>]>,
         pub parsed: Parsed<ModModule>,

crates/ruff_db/src/source.rs

@@ -11,7 +11,7 @@ use crate::Db;
 use crate::files::{File, FilePath};
 
 /// Reads the source text of a python text file (must be valid UTF8) or notebook.
-#[salsa::tracked]
+#[salsa::tracked(heap_size=get_size2::GetSize::get_heap_size)]
 pub fn source_text(db: &dyn Db, file: File) -> SourceText {
     let path = file.path(db);
     let _span = tracing::trace_span!("source_text", file = %path).entered();
@@ -65,7 +65,7 @@ fn is_notebook(path: &FilePath) -> bool {
 /// The file containing the source text can either be a text file or a notebook.
 ///
 /// Cheap cloneable in `O(1)`.
-#[derive(Clone, Eq, PartialEq)]
+#[derive(Clone, Eq, PartialEq, get_size2::GetSize)]
 pub struct SourceText {
     inner: Arc<SourceTextInner>,
 }
@@ -123,8 +123,9 @@ impl std::fmt::Debug for SourceText {
     }
 }
 
-#[derive(Eq, PartialEq)]
+#[derive(Eq, PartialEq, get_size2::GetSize)]
 struct SourceTextInner {
+    #[get_size(ignore)]
     count: Count<SourceText>,
     kind: SourceTextKind,
     read_error: Option<SourceTextError>,
@@ -136,6 +137,19 @@ enum SourceTextKind {
     Notebook(Box<Notebook>),
 }
 
+impl get_size2::GetSize for SourceTextKind {
+    fn get_heap_size(&self) -> usize {
+        match self {
+            SourceTextKind::Text(text) => text.get_heap_size(),
+            // TODO: The `get-size` derive does not support ignoring enum variants.
+            //
+            // Jupyter notebooks are not very relevant for memory profiling, and contain
+            // arbitrary JSON values that do not implement the `GetSize` trait.
+            SourceTextKind::Notebook(_) => 0,
+        }
+    }
+}
+
 impl From<String> for SourceTextKind {
     fn from(value: String) -> Self {
         SourceTextKind::Text(value)
@@ -148,7 +162,7 @@ impl From<Notebook> for SourceTextKind {
     }
 }
 
-#[derive(Debug, thiserror::Error, PartialEq, Eq, Clone)]
+#[derive(Debug, thiserror::Error, PartialEq, Eq, Clone, get_size2::GetSize)]
 pub enum SourceTextError {
     #[error("Failed to read notebook: {0}`")]
     FailedToReadNotebook(String),
@@ -157,7 +171,7 @@ pub enum SourceTextError {
 }
 
 /// Computes the [`LineIndex`] for `file`.
-#[salsa::tracked]
+#[salsa::tracked(heap_size=get_size2::GetSize::get_heap_size)]
 pub fn line_index(db: &dyn Db, file: File) -> LineIndex {
     let _span = tracing::trace_span!("line_index", ?file).entered();
 

crates/ruff_db/src/system.rs

@@ -124,6 +124,11 @@ pub trait System: Debug {
     /// Returns `None` if no such convention exists for the system.
     fn user_config_directory(&self) -> Option<SystemPathBuf>;
 
+    /// Returns the directory path where cached files are stored.
+    ///
+    /// Returns `None` if no such convention exists for the system.
+    fn cache_dir(&self) -> Option<SystemPathBuf>;
+
     /// Iterate over the contents of the directory at `path`.
     ///
     /// The returned iterator must have the following properties:
@@ -186,6 +191,9 @@ pub trait System: Debug {
         Err(std::env::VarError::NotPresent)
     }
 
+    /// Returns a handle to a [`WritableSystem`] if this system is writeable.
+    fn as_writable(&self) -> Option<&dyn WritableSystem>;
+
     fn as_any(&self) -> &dyn std::any::Any;
 
     fn as_any_mut(&mut self) -> &mut dyn std::any::Any;
@@ -226,11 +234,52 @@ impl fmt::Display for CaseSensitivity {
 
 /// System trait for non-readonly systems.
 pub trait WritableSystem: System {
+    /// Creates a file at the given path.
+    ///
+    /// Returns an error if the file already exists.
+    fn create_new_file(&self, path: &SystemPath) -> Result<()>;
+
     /// Writes the given content to the file at the given path.
     fn write_file(&self, path: &SystemPath, content: &str) -> Result<()>;
 
     /// Creates a directory at `path` as well as any intermediate directories.
     fn create_directory_all(&self, path: &SystemPath) -> Result<()>;
+
+    /// Reads the provided file from the system cache, or creates the file if necessary.
+    ///
+    /// Returns `Ok(None)` if the system does not expose a suitable cache directory.
+    fn get_or_cache(
+        &self,
+        path: &SystemPath,
+        read_contents: &dyn Fn() -> Result<String>,
+    ) -> Result<Option<SystemPathBuf>> {
+        let Some(cache_dir) = self.cache_dir() else {
+            return Ok(None);
+        };
+
+        let cache_path = cache_dir.join(path);
+
+        // The file has already been cached.
+        if self.is_file(&cache_path) {
+            return Ok(Some(cache_path));
+        }
+
+        // Read the file contents.
+        let contents = read_contents()?;
+
+        // Create the parent directory.
+        self.create_directory_all(cache_path.parent().unwrap())?;
+
+        // Create and write to the file on the system.
+        //
+        // Note that `create_new_file` will fail if the file has already been created. This
+        // ensures that only one thread/process ever attempts to write to it to avoid corrupting
+        // the cache.
+        self.create_new_file(&cache_path)?;
+        self.write_file(&cache_path, &contents)?;
+
+        Ok(Some(cache_path))
+    }
 }
 
 #[derive(Clone, Debug, Eq, PartialEq)]

crates/ruff_db/src/system/memory_fs.rs

@@ -1,4 +1,5 @@
-use std::collections::BTreeMap;
+use std::collections::{BTreeMap, btree_map};
+use std::io;
 use std::iter::FusedIterator;
 use std::sync::{Arc, RwLock, RwLockWriteGuard};
 
@@ -153,6 +154,26 @@ impl MemoryFileSystem {
         virtual_files.contains_key(&path.to_path_buf())
     }
 
+    pub(crate) fn create_new_file(&self, path: &SystemPath) -> Result<()> {
+        let normalized = self.normalize_path(path);
+
+        let mut by_path = self.inner.by_path.write().unwrap();
+        match by_path.entry(normalized) {
+            btree_map::Entry::Vacant(entry) => {
+                entry.insert(Entry::File(File {
+                    content: String::new(),
+                    last_modified: file_time_now(),
+                }));
+
+                Ok(())
+            }
+            btree_map::Entry::Occupied(_) => Err(io::Error::new(
+                io::ErrorKind::AlreadyExists,
+                "File already exists",
+            )),
+        }
+    }
+
     /// Stores a new file in the file system.
     ///
     /// The operation overrides the content for an existing file with the same normalized `path`.
@@ -278,14 +299,14 @@ impl MemoryFileSystem {
             let normalized = fs.normalize_path(path);
 
             match by_path.entry(normalized) {
-                std::collections::btree_map::Entry::Occupied(entry) => match entry.get() {
+                btree_map::Entry::Occupied(entry) => match entry.get() {
                     Entry::File(_) => {
                         entry.remove();
                         Ok(())
                     }
                     Entry::Directory(_) => Err(is_a_directory()),
                 },
-                std::collections::btree_map::Entry::Vacant(_) => Err(not_found()),
+                btree_map::Entry::Vacant(_) => Err(not_found()),
             }
         }
 
@@ -345,14 +366,14 @@ impl MemoryFileSystem {
             }
 
             match by_path.entry(normalized.clone()) {
-                std::collections::btree_map::Entry::Occupied(entry) => match entry.get() {
+                btree_map::Entry::Occupied(entry) => match entry.get() {
                     Entry::Directory(_) => {
                         entry.remove();
                         Ok(())
                     }
                     Entry::File(_) => Err(not_a_directory()),
                 },
-                std::collections::btree_map::Entry::Vacant(_) => Err(not_found()),
+                btree_map::Entry::Vacant(_) => Err(not_found()),
             }
         }
 

crates/ruff_db/src/system/os.rs

@@ -160,6 +160,39 @@ impl System for OsSystem {
         None
     }
 
+    /// Returns an absolute cache directory on the system.
+    ///
+    /// On Linux and macOS, uses `$XDG_CACHE_HOME/ty` or `.cache/ty`.
+    /// On Windows, uses `C:\Users\User\AppData\Local\ty\cache`.
+    #[cfg(not(target_arch = "wasm32"))]
+    fn cache_dir(&self) -> Option<SystemPathBuf> {
+        use etcetera::BaseStrategy as _;
+
+        let cache_dir = etcetera::base_strategy::choose_base_strategy()
+            .ok()
+            .map(|dirs| dirs.cache_dir().join("ty"))
+            .map(|cache_dir| {
+                if cfg!(windows) {
+                    // On Windows, we append `cache` to the LocalAppData directory, i.e., prefer
+                    // `C:\Users\User\AppData\Local\ty\cache` over `C:\Users\User\AppData\Local\ty`.
+                    cache_dir.join("cache")
+                } else {
+                    cache_dir
+                }
+            })
+            .and_then(|path| SystemPathBuf::from_path_buf(path).ok())
+            .unwrap_or_else(|| SystemPathBuf::from(".ty_cache"));
+
+        Some(cache_dir)
+    }
+
+    // TODO: Remove this feature gating once `ruff_wasm` no longer indirectly depends on `ruff_db` with the
+    //   `os` feature enabled (via `ruff_workspace` -> `ruff_graph` -> `ruff_db`).
+    #[cfg(target_arch = "wasm32")]
+    fn cache_dir(&self) -> Option<SystemPathBuf> {
+        None
+    }
+
     /// Creates a builder to recursively walk `path`.
     ///
     /// The walker ignores files according to [`ignore::WalkBuilder::standard_filters`]
@@ -192,6 +225,10 @@ impl System for OsSystem {
         })
     }
 
+    fn as_writable(&self) -> Option<&dyn WritableSystem> {
+        Some(self)
+    }
+
     fn as_any(&self) -> &dyn Any {
         self
     }
@@ -310,6 +347,10 @@ impl OsSystem {
 }
 
 impl WritableSystem for OsSystem {
+    fn create_new_file(&self, path: &SystemPath) -> Result<()> {
+        std::fs::File::create_new(path).map(drop)
+    }
+
     fn write_file(&self, path: &SystemPath, content: &str) -> Result<()> {
         std::fs::write(path.as_std_path(), content)
     }

crates/ruff_db/src/system/path.rs

@@ -503,6 +503,12 @@ impl ToOwned for SystemPath {
 #[cfg_attr(feature = "schemars", derive(schemars::JsonSchema))]
 pub struct SystemPathBuf(#[cfg_attr(feature = "schemars", schemars(with = "String"))] Utf8PathBuf);
 
+impl get_size2::GetSize for SystemPathBuf {
+    fn get_heap_size(&self) -> usize {
+        self.0.capacity()
+    }
+}
+
 impl SystemPathBuf {
     pub fn new() -> Self {
         Self(Utf8PathBuf::new())

crates/ruff_db/src/system/test.rs

@@ -102,6 +102,10 @@ impl System for TestSystem {
         self.system().user_config_directory()
     }
 
+    fn cache_dir(&self) -> Option<SystemPathBuf> {
+        self.system().cache_dir()
+    }
+
     fn read_directory<'a>(
         &'a self,
         path: &SystemPath,
@@ -123,6 +127,10 @@ impl System for TestSystem {
         self.system().glob(pattern)
     }
 
+    fn as_writable(&self) -> Option<&dyn WritableSystem> {
+        Some(self)
+    }
+
     fn as_any(&self) -> &dyn std::any::Any {
         self
     }
@@ -149,6 +157,10 @@ impl Default for TestSystem {
 }
 
 impl WritableSystem for TestSystem {
+    fn create_new_file(&self, path: &SystemPath) -> Result<()> {
+        self.system().create_new_file(path)
+    }
+
     fn write_file(&self, path: &SystemPath, content: &str) -> Result<()> {
         self.system().write_file(path, content)
     }
@@ -335,6 +347,10 @@ impl System for InMemorySystem {
         self.user_config_directory.lock().unwrap().clone()
     }
 
+    fn cache_dir(&self) -> Option<SystemPathBuf> {
+        None
+    }
+
     fn read_directory<'a>(
         &'a self,
         path: &SystemPath,
@@ -357,6 +373,10 @@ impl System for InMemorySystem {
         Ok(Box::new(iterator))
     }
 
+    fn as_writable(&self) -> Option<&dyn WritableSystem> {
+        Some(self)
+    }
+
     fn as_any(&self) -> &dyn std::any::Any {
         self
     }
@@ -377,6 +397,10 @@ impl System for InMemorySystem {
 }
 
 impl WritableSystem for InMemorySystem {
+    fn create_new_file(&self, path: &SystemPath) -> Result<()> {
+        self.memory_fs.create_new_file(path)
+    }
+
     fn write_file(&self, path: &SystemPath, content: &str) -> Result<()> {
         self.memory_fs.write_file(path, content)
     }

crates/ruff_db/src/system/walk_directory.rs

@@ -212,7 +212,7 @@ impl Display for Error {
                 path: Some(path),
                 err,
             } => {
-                write!(f, "IO error for operation on {}: {}", path, err)
+                write!(f, "IO error for operation on {path}: {err}")
             }
             ErrorKind::Io { path: None, err } => err.fmt(f),
             ErrorKind::NonUtf8Path { path } => {

crates/ruff_db/src/vendored.rs

@@ -4,12 +4,12 @@ use std::fmt::{self, Debug};
 use std::io::{self, Read, Write};
 use std::sync::{Arc, Mutex, MutexGuard};
 
-use crate::file_revision::FileRevision;
 use zip::result::ZipResult;
 use zip::write::FileOptions;
 use zip::{CompressionMethod, ZipArchive, ZipWriter, read::ZipFile};
 
 pub use self::path::{VendoredPath, VendoredPathBuf};
+use crate::file_revision::FileRevision;
 
 mod path;
 

crates/ruff_db/src/vendored/path.rs

@@ -87,6 +87,12 @@ impl ToOwned for VendoredPath {
 #[derive(Debug, Eq, PartialEq, Clone, Hash)]
 pub struct VendoredPathBuf(Utf8PathBuf);
 
+impl get_size2::GetSize for VendoredPathBuf {
+    fn get_heap_size(&self) -> usize {
+        self.0.capacity()
+    }
+}
+
 impl Default for VendoredPathBuf {
     fn default() -> Self {
         Self::new()

crates/ruff_dev/src/generate_ty_options.rs

@@ -114,6 +114,7 @@ fn generate_set(output: &mut String, set: Set, parents: &mut Vec<Set>) {
     parents.pop();
 }
 
+#[derive(Debug)]
 enum Set {
     Toplevel(OptionSet),
     Named { name: String, set: OptionSet },
@@ -136,7 +137,7 @@ impl Set {
 }
 
 fn emit_field(output: &mut String, name: &str, field: &OptionField, parents: &[Set]) {
-    let header_level = if parents.is_empty() { "###" } else { "####" };
+    let header_level = "#".repeat(parents.len() + 1);
 
     let _ = writeln!(output, "{header_level} `{name}`");
 

crates/ruff_dev/src/generate_ty_rules.rs

@@ -73,12 +73,20 @@ fn generate_markdown() -> String {
     for lint in lints {
         let _ = writeln!(&mut output, "## `{rule_name}`\n", rule_name = lint.name());
 
-        // Increase the header-level by one
+        // Reformat headers as bold text
+        let mut in_code_fence = false;
         let documentation = lint
             .documentation_lines()
             .map(|line| {
-                if line.starts_with('#') {
-                    Cow::Owned(format!("#{line}"))
+                // Toggle the code fence state if we encounter a boundary
+                if line.starts_with("```") {
+                    in_code_fence = !in_code_fence;
+                }
+                if !in_code_fence && line.starts_with('#') {
+                    Cow::Owned(format!(
+                        "**{line}**\n",
+                        line = line.trim_start_matches('#').trim_start()
+                    ))
                 } else {
                     Cow::Borrowed(line)
                 }
@@ -87,21 +95,15 @@ fn generate_markdown() -> String {
 
         let _ = writeln!(
             &mut output,
-            r#"**Default level**: {level}
-
-<details>
-<summary>{summary}</summary>
+            r#"<small>
+Default level: [`{level}`](../rules.md#rule-levels "This lint has a default level of '{level}'.") ·
+[Related issues](https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20{encoded_name}) ·
+[View source](https://github.com/astral-sh/ruff/blob/main/{file}#L{line})
+</small>
 
 {documentation}
-
-### Links
-* [Related issues](https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20{encoded_name})
-* [View source](https://github.com/astral-sh/ruff/blob/main/{file}#L{line})
-</details>
 "#,
             level = lint.default_level(),
-            // GitHub doesn't support markdown in `summary` headers
-            summary = replace_inline_code(lint.summary()),
             encoded_name = url::form_urlencoded::byte_serialize(lint.name().as_str().as_bytes())
                 .collect::<String>(),
             file = url::form_urlencoded::byte_serialize(lint.file().replace('\\', "/").as_bytes())
@@ -113,25 +115,6 @@ fn generate_markdown() -> String {
     output
 }
 
-/// Replaces inline code blocks (`code`) with `<code>code</code>`
-fn replace_inline_code(input: &str) -> String {
-    let mut output = String::new();
-    let mut parts = input.split('`');
-
-    while let Some(before) = parts.next() {
-        if let Some(between) = parts.next() {
-            output.push_str(before);
-            output.push_str("<code>");
-            output.push_str(between);
-            output.push_str("</code>");
-        } else {
-            output.push_str(before);
-        }
-    }
-
-    output
-}
-
 #[cfg(test)]
 mod tests {
     use anyhow::Result;

crates/ruff_graph/src/db.rs

@@ -2,10 +2,10 @@ use anyhow::{Context, Result};
 use std::sync::Arc;
 use zip::CompressionMethod;
 
+use ruff_db::Db as SourceDb;
 use ruff_db::files::{File, Files};
 use ruff_db::system::{OsSystem, System, SystemPathBuf};
 use ruff_db::vendored::{VendoredFileSystem, VendoredFileSystemBuilder};
-use ruff_db::{Db as SourceDb, Upcast};
 use ruff_python_ast::PythonVersion;
 use ty_python_semantic::lint::{LintRegistry, RuleSelection};
 use ty_python_semantic::{
@@ -66,15 +66,6 @@ impl ModuleDb {
     }
 }
 
-impl Upcast<dyn SourceDb> for ModuleDb {
-    fn upcast(&self) -> &(dyn SourceDb + 'static) {
-        self
-    }
-    fn upcast_mut(&mut self) -> &mut (dyn SourceDb + 'static) {
-        self
-    }
-}
-
 #[salsa::db]
 impl SourceDb for ModuleDb {
     fn vendored(&self) -> &VendoredFileSystem {

crates/ruff_index/Cargo.toml

@@ -14,6 +14,7 @@ license = { workspace = true }
 doctest = false
 
 [dependencies]
+get-size2 = { workspace = true }
 ruff_macros = { workspace = true }
 salsa = { workspace = true, optional = true }
 

crates/ruff_index/src/vec.rs

@@ -6,7 +6,7 @@ use std::marker::PhantomData;
 use std::ops::{Deref, DerefMut, RangeBounds};
 
 /// An owned sequence of `T` indexed by `I`
-#[derive(Clone, PartialEq, Eq, Hash)]
+#[derive(Clone, PartialEq, Eq, Hash, get_size2::GetSize)]
 #[repr(transparent)]
 pub struct IndexVec<I, T> {
     pub raw: Vec<T>,
@@ -191,6 +191,6 @@ where
     #[expect(unsafe_code)]
     unsafe fn maybe_update(old_pointer: *mut Self, new_value: Self) -> bool {
         let old_vec: &mut IndexVec<I, T> = unsafe { &mut *old_pointer };
-        unsafe { salsa::Update::maybe_update(&mut old_vec.raw, new_value.raw) }
+        unsafe { salsa::Update::maybe_update(&raw mut old_vec.raw, new_value.raw) }
     }
 }

crates/ruff_linter/Cargo.toml

@@ -38,6 +38,7 @@ colored = { workspace = true }
 fern = { workspace = true }
 glob = { workspace = true }
 globset = { workspace = true }
+hashbrown = { workspace = true }
 imperative = { workspace = true }
 is-macro = { workspace = true }
 is-wsl = { workspace = true }

crates/ruff_linter/resources/test/fixtures/flake8_comprehensions/C420_2.py

@@ -0,0 +1,5 @@
+foo or{x: None for x in bar}
+
+
+# C420 fix must make sure to insert a leading space if needed,
+# See https://github.com/astral-sh/ruff/issues/18599

crates/ruff_linter/resources/test/fixtures/flake8_executable/EXE003_uv_tool.py

@@ -0,0 +1,2 @@
+#!/usr/bin/env -S uv tool run ruff check --isolated --select EXE003
+print("hello world")

crates/ruff_linter/resources/test/fixtures/flake8_executable/EXE003_uvx.py

@@ -0,0 +1,2 @@
+#!/usr/bin/env -S uvx ruff check --isolated --select EXE003
+print("hello world")

crates/ruff_linter/resources/test/fixtures/flake8_pyi/PYI016.py

@@ -119,4 +119,26 @@ field35: "int | str | int"  # Error
 # Technically, this falls into the domain of the rule but it is an unlikely edge case,
 # only works if you have from `__future__ import annotations` at the top of the file,
 # and stringified annotations are discouraged in stub files.
-field36: "int | str" | int  # Ok
+field36: "int | str" | int  # Ok
+
+# https://github.com/astral-sh/ruff/issues/18546
+# Expand Optional[T] to Union[T, None]
+# OK
+field37: typing.Optional[int]
+field38: typing.Union[int, None]
+# equivalent to None
+field39: typing.Optional[None]
+# equivalent to int | None
+field40: typing.Union[typing.Optional[int], None]
+field41: typing.Optional[typing.Union[int, None]]
+field42: typing.Union[typing.Optional[int], typing.Optional[int]]
+field43: typing.Optional[int] | None
+field44: typing.Optional[int | None]
+field45: typing.Optional[int] | typing.Optional[int]
+# equivalent to int | dict | None
+field46: typing.Union[typing.Optional[int], typing.Optional[dict]]
+field47: typing.Optional[int] | typing.Optional[dict]
+
+# avoid reporting twice
+field48: typing.Union[typing.Optional[typing.Union[complex, complex]], complex]
+field49: typing.Optional[complex | complex] | complex

crates/ruff_linter/resources/test/fixtures/flake8_pyi/PYI016.pyi

@@ -111,3 +111,25 @@ field33: typing.Union[typing.Union[int | int] | typing.Union[int | int]] # Error
 
 # Test case for mixed union type
 field34: typing.Union[list[int], str] | typing.Union[bytes, list[int]]  # Error
+
+# https://github.com/astral-sh/ruff/issues/18546
+# Expand Optional[T] to Union[T, None]
+# OK
+field37: typing.Optional[int]
+field38: typing.Union[int, None]
+# equivalent to None
+field39: typing.Optional[None]
+# equivalent to int | None
+field40: typing.Union[typing.Optional[int], None]
+field41: typing.Optional[typing.Union[int, None]]
+field42: typing.Union[typing.Optional[int], typing.Optional[int]]
+field43: typing.Optional[int] | None
+field44: typing.Optional[int | None]
+field45: typing.Optional[int] | typing.Optional[int]
+# equivalent to int | dict | None
+field46: typing.Union[typing.Optional[int], typing.Optional[dict]]
+field47: typing.Optional[int] | typing.Optional[dict]
+
+# avoid reporting twice
+field48: typing.Union[typing.Optional[typing.Union[complex, complex]], complex]
+field49: typing.Optional[complex | complex] | complex

crates/ruff_linter/resources/test/fixtures/perflint/PERF403.py

@@ -170,3 +170,25 @@ def foo():
     v = {}
     for o,(x,)in():
         v[x,]=o
+
+
+# https://github.com/astral-sh/ruff/issues/19005
+def issue_19005_1():
+    c = {}
+    a = object()
+    for a.b in ():
+        c[a.b] = a.b
+
+
+def issue_19005_2():
+    a = object()
+    c = {}
+    for a.k, a.v in ():
+        c[a.k] = a.v
+
+
+def issue_19005_3():
+    a = [None, None]
+    c = {}
+    for a[0], a[1] in ():
+        c[a[0]] = a[1]

crates/ruff_linter/resources/test/fixtures/pydocstyle/D413.py

@@ -69,3 +69,11 @@ def func():
     Returns:
         the value
         """
+
+
+def func():
+    ("""Docstring.
+
+    Raises:
+        ValueError: An error.
+    """)

crates/ruff_linter/resources/test/fixtures/pylint/unnecessary_lambda.py

@@ -57,3 +57,7 @@ _ = lambda x: z(lambda y: x + y)(x)
 # lambda uses an additional keyword
 _ = lambda *args: f(*args, y=1)
 _ = lambda *args: f(*args, y=x)
+
+# https://github.com/astral-sh/ruff/issues/18675
+_ = lambda x: (string := str)(x)
+_ = lambda x: ((x := 1) and str)(x)

crates/ruff_linter/resources/test/fixtures/pyupgrade/UP007.py

@@ -90,3 +90,52 @@ class AClass:
 
 def myfunc(param: "tuple[Union[int, 'AClass', None], str]"):
     print(param)
+
+
+from typing import NamedTuple, Union
+
+import typing_extensions
+from typing_extensions import (
+    NamedTuple as NamedTupleTE,
+    Union as UnionTE,
+)
+
+# Regression test for https://github.com/astral-sh/ruff/issues/18619
+# Don't emit lint for `NamedTuple`
+a_plain_1: Union[NamedTuple, int] = None
+a_plain_2: Union[int, NamedTuple] = None
+a_plain_3: Union[NamedTuple, None] = None
+a_plain_4: Union[None, NamedTuple] = None
+a_plain_te_1: UnionTE[NamedTupleTE, int] = None
+a_plain_te_2: UnionTE[int, NamedTupleTE] = None
+a_plain_te_3: UnionTE[NamedTupleTE, None] = None
+a_plain_te_4: UnionTE[None, NamedTupleTE] = None
+a_plain_typing_1: UnionTE[typing.NamedTuple, int] = None
+a_plain_typing_2: UnionTE[int, typing.NamedTuple] = None
+a_plain_typing_3: UnionTE[typing.NamedTuple, None] = None
+a_plain_typing_4: UnionTE[None, typing.NamedTuple] = None
+a_string_1: "Union[NamedTuple, int]" = None
+a_string_2: "Union[int, NamedTuple]" = None
+a_string_3: "Union[NamedTuple, None]" = None
+a_string_4: "Union[None, NamedTuple]" = None
+a_string_te_1: "UnionTE[NamedTupleTE, int]" = None
+a_string_te_2: "UnionTE[int, NamedTupleTE]" = None
+a_string_te_3: "UnionTE[NamedTupleTE, None]" = None
+a_string_te_4: "UnionTE[None, NamedTupleTE]" = None
+a_string_typing_1: "typing.Union[typing.NamedTuple, int]" = None
+a_string_typing_2: "typing.Union[int, typing.NamedTuple]" = None
+a_string_typing_3: "typing.Union[typing.NamedTuple, None]" = None
+a_string_typing_4: "typing.Union[None, typing.NamedTuple]" = None
+
+b_plain_1: Union[NamedTuple] = None
+b_plain_2: Union[NamedTuple, None] = None
+b_plain_te_1: UnionTE[NamedTupleTE] = None
+b_plain_te_2: UnionTE[NamedTupleTE, None] = None
+b_plain_typing_1: UnionTE[typing.NamedTuple] = None
+b_plain_typing_2: UnionTE[typing.NamedTuple, None] = None
+b_string_1: "Union[NamedTuple]" = None
+b_string_2: "Union[NamedTuple, None]" = None
+b_string_te_1: "UnionTE[NamedTupleTE]" = None
+b_string_te_2: "UnionTE[NamedTupleTE, None]" = None
+b_string_typing_1: "typing.Union[typing.NamedTuple]" = None
+b_string_typing_2: "typing.Union[typing.NamedTuple, None]" = None

crates/ruff_linter/resources/test/fixtures/pyupgrade/UP008.py

@@ -105,3 +105,23 @@ import builtins
 class C:
     def f(self):
         builtins.super(C, self)
+
+
+# see: https://github.com/astral-sh/ruff/issues/18533
+class ClassForCommentEnthusiasts(BaseClass):
+    def with_comments(self):
+        super(
+            # super helpful comment
+            ClassForCommentEnthusiasts,
+            self
+        ).f()
+        super(
+            ClassForCommentEnthusiasts,
+            # even more helpful comment
+            self
+        ).f()
+        super(
+            ClassForCommentEnthusiasts,
+            self
+            # also a comment
+        ).f()

crates/ruff_linter/resources/test/fixtures/pyupgrade/UP025.py

@@ -26,3 +26,9 @@ def hello():
 
 f"foo"u"bar"  # OK
 f"foo" u"bar"  # OK
+
+# https://github.com/astral-sh/ruff/issues/18895
+""u""
+""u"hi"
+""""""""""""""""""""u"hi"
+""U"helloooo"

crates/ruff_linter/resources/test/fixtures/pyupgrade/UP045.py

@@ -47,3 +47,25 @@ class ServiceRefOrValue:
 # Test for: https://github.com/astral-sh/ruff/issues/18508
 # Optional[None] should not be offered a fix
 foo: Optional[None] = None
+
+
+from typing import NamedTuple, Optional
+
+import typing_extensions
+from typing_extensions import (
+    NamedTuple as NamedTupleTE,
+    Optional as OptionalTE,
+)
+
+# Regression test for https://github.com/astral-sh/ruff/issues/18619
+# Don't emit lint for `NamedTuple`
+a1: Optional[NamedTuple] = None
+a2: typing.Optional[NamedTuple] = None
+a3: OptionalTE[NamedTuple] = None
+a4: typing_extensions.Optional[NamedTuple] = None
+a5: Optional[typing.NamedTuple] = None
+a6: typing.Optional[typing.NamedTuple] = None
+a7: OptionalTE[typing.NamedTuple] = None
+a8: typing_extensions.Optional[typing.NamedTuple] = None
+a9: "Optional[NamedTuple]" = None
+a10: Optional[NamedTupleTE] = None

crates/ruff_linter/resources/test/fixtures/refurb/FURB168.py

@@ -85,3 +85,10 @@ def _():
 
     if isinstance(foo, type(None)):
         ...
+
+# https://github.com/astral-sh/ruff/issues/19047
+if isinstance(foo, ()):
+    pass
+
+if isinstance(foo, Union[()]):
+    pass

crates/ruff_linter/src/checkers/ast/analyze/expression.rs

@@ -7,6 +7,7 @@ use ruff_python_semantic::analyze::typing;
 use ruff_text_size::Ranged;
 
 use crate::checkers::ast::Checker;
+use crate::preview::is_optional_as_none_in_union_enabled;
 use crate::registry::Rule;
 use crate::rules::{
     airflow, flake8_2020, flake8_async, flake8_bandit, flake8_boolean_trap, flake8_bugbear,
@@ -90,7 +91,13 @@ pub(crate) fn expression(expr: &Expr, checker: &Checker) {
                     if checker.is_rule_enabled(Rule::UnnecessaryLiteralUnion) {
                         flake8_pyi::rules::unnecessary_literal_union(checker, expr);
                     }
-                    if checker.is_rule_enabled(Rule::DuplicateUnionMember) {
+                    if checker.is_rule_enabled(Rule::DuplicateUnionMember)
+                        // Avoid duplicate checks inside `Optional`
+                        && !(
+                            is_optional_as_none_in_union_enabled(checker.settings())
+                            && checker.semantic.inside_optional()
+                        )
+                    {
                         flake8_pyi::rules::duplicate_union_member(checker, expr);
                     }
                     if checker.is_rule_enabled(Rule::RedundantLiteralUnion) {
@@ -1430,6 +1437,11 @@ pub(crate) fn expression(expr: &Expr, checker: &Checker) {
             if !checker.semantic.in_nested_union() {
                 if checker.is_rule_enabled(Rule::DuplicateUnionMember)
                     && checker.semantic.in_type_definition()
+                    // Avoid duplicate checks inside `Optional`
+                    && !(
+                        is_optional_as_none_in_union_enabled(checker.settings())
+                        && checker.semantic.inside_optional()
+                    )
                 {
                     flake8_pyi::rules::duplicate_union_member(checker, expr);
                 }

crates/ruff_linter/src/checkers/ast/mod.rs

@@ -2765,9 +2765,7 @@ impl<'a> Checker<'a> {
 
                         self.semantic.restore(snapshot);
 
-                        if self.semantic.in_annotation()
-                            && self.semantic.in_typing_only_annotation()
-                        {
+                        if self.semantic.in_typing_only_annotation() {
                             if self.is_rule_enabled(Rule::QuotedAnnotation) {
                                 pyupgrade::rules::quoted_annotation(self, annotation, range);
                             }

crates/ruff_linter/src/checkers/noqa.rs

@@ -35,39 +35,34 @@ pub(crate) fn check_noqa(
     // Identify any codes that are globally exempted (within the current file).
     let file_noqa_directives =
         FileNoqaDirectives::extract(locator, comment_ranges, &settings.external, path);
-    let exemption = FileExemption::from(&file_noqa_directives);
 
     // Extract all `noqa` directives.
     let mut noqa_directives =
         NoqaDirectives::from_commented_ranges(comment_ranges, &settings.external, path, locator);
 
+    if file_noqa_directives.is_empty() && noqa_directives.is_empty() {
+        return Vec::new();
+    }
+
+    let exemption = FileExemption::from(&file_noqa_directives);
+
     // Indices of diagnostics that were ignored by a `noqa` directive.
     let mut ignored_diagnostics = vec![];
 
     // Remove any ignored diagnostics.
     'outer: for (index, diagnostic) in context.iter().enumerate() {
         // Can't ignore syntax errors.
-        let Some(code) = diagnostic.noqa_code() else {
+        let Some(code) = diagnostic.secondary_code() else {
             continue;
         };
 
-        if code == Rule::BlanketNOQA.noqa_code() {
+        if *code == Rule::BlanketNOQA.noqa_code() {
             continue;
         }
 
-        match &exemption {
-            FileExemption::All(_) => {
-                // If the file is exempted, ignore all diagnostics.
-                ignored_diagnostics.push(index);
-                continue;
-            }
-            FileExemption::Codes(codes) => {
-                // If the diagnostic is ignored by a global exemption, ignore it.
-                if codes.contains(&&code) {
-                    ignored_diagnostics.push(index);
-                    continue;
-                }
-            }
+        if exemption.contains_secondary_code(code) {
+            ignored_diagnostics.push(index);
+            continue;
         }
 
         let noqa_offsets = diagnostic
@@ -82,13 +77,21 @@ pub(crate) fn check_noqa(
             {
                 let suppressed = match &directive_line.directive {
                     Directive::All(_) => {
-                        directive_line.matches.push(code);
+                        let Ok(rule) = Rule::from_code(code) else {
+                            debug_assert!(false, "Invalid secondary code `{code}`");
+                            continue;
+                        };
+                        directive_line.matches.push(rule);
                         ignored_diagnostics.push(index);
                         true
                     }
                     Directive::Codes(directive) => {
                         if directive.includes(code) {
-                            directive_line.matches.push(code);
+                            let Ok(rule) = Rule::from_code(code) else {
+                                debug_assert!(false, "Invalid secondary code `{code}`");
+                                continue;
+                            };
+                            directive_line.matches.push(rule);
                             ignored_diagnostics.push(index);
                             true
                         } else {
@@ -147,11 +150,11 @@ pub(crate) fn check_noqa(
 
                         if seen_codes.insert(original_code) {
                             let is_code_used = if is_file_level {
-                                context
-                                    .iter()
-                                    .any(|diag| diag.noqa_code().is_some_and(|noqa| noqa == code))
+                                context.iter().any(|diag| {
+                                    diag.secondary_code().is_some_and(|noqa| *noqa == code)
+                                })
                             } else {
-                                matches.iter().any(|match_| *match_ == code)
+                                matches.iter().any(|match_| match_.noqa_code() == code)
                             } || settings
                                 .external
                                 .iter()

crates/ruff_linter/src/codes.rs

@@ -46,6 +46,12 @@ impl PartialEq<&str> for NoqaCode {
     }
 }
 
+impl PartialEq<NoqaCode> for &str {
+    fn eq(&self, other: &NoqaCode) -> bool {
+        other.eq(self)
+    }
+}
+
 impl serde::Serialize for NoqaCode {
     fn serialize<S>(&self, serializer: S) -> std::result::Result<S::Ok, S::Error>
     where

crates/ruff_linter/src/fix/mod.rs

@@ -63,7 +63,7 @@ fn apply_fixes<'a>(
     let mut source_map = SourceMap::default();
 
     for (code, name, fix) in diagnostics
-        .filter_map(|msg| msg.noqa_code().map(|code| (code, msg.name(), msg)))
+        .filter_map(|msg| msg.secondary_code().map(|code| (code, msg.name(), msg)))
         .filter_map(|(code, name, diagnostic)| diagnostic.fix().map(|fix| (code, name, fix)))
         .sorted_by(|(_, name1, fix1), (_, name2, fix2)| cmp_fix(name1, name2, fix1, fix2))
     {

crates/ruff_linter/src/linter.rs

@@ -1,12 +1,11 @@
 use std::borrow::Cow;
-use std::collections::hash_map::Entry;
 use std::path::Path;
 
 use anyhow::{Result, anyhow};
 use colored::Colorize;
 use itertools::Itertools;
 use ruff_python_parser::semantic_errors::SemanticSyntaxError;
-use rustc_hash::FxHashMap;
+use rustc_hash::FxBuildHasher;
 
 use ruff_notebook::Notebook;
 use ruff_python_ast::{ModModule, PySourceType, PythonVersion};
@@ -23,10 +22,10 @@ use crate::checkers::imports::check_imports;
 use crate::checkers::noqa::check_noqa;
 use crate::checkers::physical_lines::check_physical_lines;
 use crate::checkers::tokens::check_tokens;
-use crate::codes::NoqaCode;
 use crate::directives::Directives;
 use crate::doc_lines::{doc_lines_from_ast, doc_lines_from_tokens};
 use crate::fix::{FixResult, fix_file};
+use crate::message::SecondaryCode;
 use crate::noqa::add_noqa;
 use crate::package::PackageRoot;
 use crate::preview::is_py314_support_enabled;
@@ -95,25 +94,25 @@ struct FixCount {
 
 /// A mapping from a noqa code to the corresponding lint name and a count of applied fixes.
 #[derive(Debug, Default, PartialEq)]
-pub struct FixTable(FxHashMap<NoqaCode, FixCount>);
+pub struct FixTable(hashbrown::HashMap<SecondaryCode, FixCount, rustc_hash::FxBuildHasher>);
 
 impl FixTable {
     pub fn counts(&self) -> impl Iterator<Item = usize> {
         self.0.values().map(|fc| fc.count)
     }
 
-    pub fn entry(&mut self, code: NoqaCode) -> FixTableEntry {
-        FixTableEntry(self.0.entry(code))
+    pub fn entry<'a>(&'a mut self, code: &'a SecondaryCode) -> FixTableEntry<'a> {
+        FixTableEntry(self.0.entry_ref(code))
     }
 
-    pub fn iter(&self) -> impl Iterator<Item = (NoqaCode, &'static str, usize)> {
+    pub fn iter(&self) -> impl Iterator<Item = (&SecondaryCode, &'static str, usize)> {
         self.0
             .iter()
-            .map(|(code, FixCount { rule_name, count })| (*code, *rule_name, *count))
+            .map(|(code, FixCount { rule_name, count })| (code, *rule_name, *count))
     }
 
-    pub fn keys(&self) -> impl Iterator<Item = NoqaCode> {
-        self.0.keys().copied()
+    pub fn keys(&self) -> impl Iterator<Item = &SecondaryCode> {
+        self.0.keys()
     }
 
     pub fn is_empty(&self) -> bool {
@@ -121,7 +120,9 @@ impl FixTable {
     }
 }
 
-pub struct FixTableEntry<'a>(Entry<'a, NoqaCode, FixCount>);
+pub struct FixTableEntry<'a>(
+    hashbrown::hash_map::EntryRef<'a, 'a, SecondaryCode, SecondaryCode, FixCount, FxBuildHasher>,
+);
 
 impl<'a> FixTableEntry<'a> {
     pub fn or_default(self, rule_name: &'static str) -> &'a mut usize {
@@ -678,18 +679,16 @@ pub fn lint_fix<'a>(
     }
 }
 
-fn collect_rule_codes(rules: impl IntoIterator<Item = NoqaCode>) -> String {
-    rules
-        .into_iter()
-        .map(|rule| rule.to_string())
-        .sorted_unstable()
-        .dedup()
-        .join(", ")
+fn collect_rule_codes<T>(rules: impl IntoIterator<Item = T>) -> String
+where
+    T: Ord + PartialEq + std::fmt::Display,
+{
+    rules.into_iter().sorted_unstable().dedup().join(", ")
 }
 
 #[expect(clippy::print_stderr)]
 fn report_failed_to_converge_error(path: &Path, transformed: &str, diagnostics: &[OldDiagnostic]) {
-    let codes = collect_rule_codes(diagnostics.iter().filter_map(OldDiagnostic::noqa_code));
+    let codes = collect_rule_codes(diagnostics.iter().filter_map(OldDiagnostic::secondary_code));
     if cfg!(debug_assertions) {
         eprintln!(
             "{}{} Failed to converge after {} iterations in `{}` with rule codes {}:---\n{}\n---",
@@ -721,11 +720,11 @@ This indicates a bug in Ruff. If you could open an issue at:
 }
 
 #[expect(clippy::print_stderr)]
-fn report_fix_syntax_error(
+fn report_fix_syntax_error<'a>(
     path: &Path,
     transformed: &str,
     error: &ParseError,
-    rules: impl IntoIterator<Item = NoqaCode>,
+    rules: impl IntoIterator<Item = &'a SecondaryCode>,
 ) {
     let codes = collect_rule_codes(rules);
     if cfg!(debug_assertions) {

crates/ruff_linter/src/message/azure.rs

@@ -33,7 +33,7 @@ impl Emitter for AzureEmitter {
                 line = location.line,
                 col = location.column,
                 code = diagnostic
-                    .noqa_code()
+                    .secondary_code()
                     .map_or_else(String::new, |code| format!("code={code};")),
                 body = diagnostic.body(),
             )?;

crates/ruff_linter/src/message/github.rs

@@ -33,7 +33,7 @@ impl Emitter for GithubEmitter {
                 writer,
                 "::error title=Ruff{code},file={file},line={row},col={column},endLine={end_row},endColumn={end_column}::",
                 code = diagnostic
-                    .noqa_code()
+                    .secondary_code()
                     .map_or_else(String::new, |code| format!(" ({code})")),
                 file = diagnostic.filename(),
                 row = source_location.line,
@@ -50,7 +50,7 @@ impl Emitter for GithubEmitter {
                 column = location.column,
             )?;
 
-            if let Some(code) = diagnostic.noqa_code() {
+            if let Some(code) = diagnostic.secondary_code() {
                 write!(writer, " {code}")?;
             }
 

crates/ruff_linter/src/message/gitlab.rs

@@ -90,18 +90,15 @@ impl Serialize for SerializedMessages<'_> {
             }
             fingerprints.insert(message_fingerprint);
 
-            let (description, check_name) = if let Some(code) = diagnostic.noqa_code() {
-                (diagnostic.body().to_string(), code.to_string())
+            let (description, check_name) = if let Some(code) = diagnostic.secondary_code() {
+                (diagnostic.body().to_string(), code.as_str())
             } else {
                 let description = diagnostic.body();
                 let description_without_prefix = description
                     .strip_prefix("SyntaxError: ")
                     .unwrap_or(description);
 
-                (
-                    description_without_prefix.to_string(),
-                    "syntax-error".to_string(),
-                )
+                (description_without_prefix.to_string(), "syntax-error")
             };
 
             let value = json!({

crates/ruff_linter/src/message/json.rs

@@ -87,7 +87,7 @@ pub(crate) fn message_to_json_value(message: &OldDiagnostic, context: &EmitterCo
     }
 
     json!({
-        "code": message.noqa_code().map(|code| code.to_string()),
+        "code": message.secondary_code(),
         "url": message.to_url(),
         "message": message.body(),
         "fix": fix,

crates/ruff_linter/src/message/junit.rs

@@ -59,7 +59,7 @@ impl Emitter for JunitEmitter {
                         body = message.body()
                     ));
                     let mut case = TestCase::new(
-                        if let Some(code) = message.noqa_code() {
+                        if let Some(code) = message.secondary_code() {
                             format!("org.ruff.{code}")
                         } else {
                             "org.ruff".to_string()

crates/ruff_linter/src/message/mod.rs

@@ -62,7 +62,7 @@ pub struct OldDiagnostic {
     pub fix: Option<Fix>,
     pub parent: Option<TextSize>,
     pub(crate) noqa_offset: Option<TextSize>,
-    pub(crate) noqa_code: Option<NoqaCode>,
+    pub(crate) secondary_code: Option<SecondaryCode>,
 }
 
 impl OldDiagnostic {
@@ -79,7 +79,7 @@ impl OldDiagnostic {
             fix: None,
             parent: None,
             noqa_offset: None,
-            noqa_code: None,
+            secondary_code: None,
         }
     }
 
@@ -115,7 +115,7 @@ impl OldDiagnostic {
             fix,
             parent,
             noqa_offset,
-            noqa_code: Some(rule.noqa_code()),
+            secondary_code: Some(SecondaryCode(rule.noqa_code().to_string())),
         }
     }
 
@@ -247,9 +247,9 @@ impl OldDiagnostic {
         self.fix().is_some()
     }
 
-    /// Returns the [`NoqaCode`] corresponding to the diagnostic message.
-    pub fn noqa_code(&self) -> Option<NoqaCode> {
-        self.noqa_code
+    /// Returns the noqa code for the diagnostic message as a string.
+    pub fn secondary_code(&self) -> Option<&SecondaryCode> {
+        self.secondary_code.as_ref()
     }
 
     /// Returns the URL for the rule documentation, if it exists.
@@ -384,6 +384,68 @@ impl<'a> EmitterContext<'a> {
     }
 }
 
+/// A secondary identifier for a lint diagnostic.
+///
+/// For Ruff rules this means the noqa code.
+#[derive(Clone, Debug, PartialEq, Eq, PartialOrd, Ord, Default, Hash, serde::Serialize)]
+#[serde(transparent)]
+pub struct SecondaryCode(String);
+
+impl SecondaryCode {
+    pub fn new(code: String) -> Self {
+        Self(code)
+    }
+
+    pub fn as_str(&self) -> &str {
+        &self.0
+    }
+}
+
+impl Display for SecondaryCode {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        f.write_str(&self.0)
+    }
+}
+
+impl std::ops::Deref for SecondaryCode {
+    type Target = str;
+
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
+
+impl PartialEq<&str> for SecondaryCode {
+    fn eq(&self, other: &&str) -> bool {
+        self.0 == *other
+    }
+}
+
+impl PartialEq<SecondaryCode> for &str {
+    fn eq(&self, other: &SecondaryCode) -> bool {
+        other.eq(self)
+    }
+}
+
+impl PartialEq<NoqaCode> for SecondaryCode {
+    fn eq(&self, other: &NoqaCode) -> bool {
+        &self.as_str() == other
+    }
+}
+
+impl PartialEq<SecondaryCode> for NoqaCode {
+    fn eq(&self, other: &SecondaryCode) -> bool {
+        other.eq(self)
+    }
+}
+
+// for `hashbrown::EntryRef`
+impl From<&SecondaryCode> for SecondaryCode {
+    fn from(value: &SecondaryCode) -> Self {
+        value.clone()
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use rustc_hash::FxHashMap;

crates/ruff_linter/src/message/pylint.rs

@@ -26,7 +26,7 @@ impl Emitter for PylintEmitter {
                 diagnostic.compute_start_location().line
             };
 
-            let body = if let Some(code) = diagnostic.noqa_code() {
+            let body = if let Some(code) = diagnostic.secondary_code() {
                 format!("[{code}] {body}", body = diagnostic.body())
             } else {
                 diagnostic.body().to_string()

crates/ruff_linter/src/message/rdjson.rs

@@ -71,7 +71,7 @@ fn message_to_rdjson_value(message: &OldDiagnostic) -> Value {
                 "range": rdjson_range(start_location, end_location),
             },
             "code": {
-                "value": message.noqa_code().map(|code| code.to_string()),
+                "value": message.secondary_code(),
                 "url": message.to_url(),
             },
             "suggestions": rdjson_suggestions(fix.edits(), &source_code),
@@ -84,7 +84,7 @@ fn message_to_rdjson_value(message: &OldDiagnostic) -> Value {
                 "range": rdjson_range(start_location, end_location),
             },
             "code": {
-                "value": message.noqa_code().map(|code| code.to_string()),
+                "value": message.secondary_code(),
                 "url": message.to_url(),
             },
         })

crates/ruff_linter/src/message/sarif.rs

@@ -8,9 +8,8 @@ use serde_json::json;
 use ruff_source_file::OneIndexed;
 
 use crate::VERSION;
-use crate::codes::NoqaCode;
 use crate::fs::normalize_path;
-use crate::message::{Emitter, EmitterContext, OldDiagnostic};
+use crate::message::{Emitter, EmitterContext, OldDiagnostic, SecondaryCode};
 use crate::registry::{Linter, RuleNamespace};
 
 pub struct SarifEmitter;
@@ -29,7 +28,7 @@ impl Emitter for SarifEmitter {
 
         let unique_rules: HashSet<_> = results.iter().filter_map(|result| result.code).collect();
         let mut rules: Vec<SarifRule> = unique_rules.into_iter().map(SarifRule::from).collect();
-        rules.sort_by(|a, b| a.code.cmp(&b.code));
+        rules.sort_by(|a, b| a.code.cmp(b.code));
 
         let output = json!({
             "$schema": "https://json.schemastore.org/sarif-2.1.0.json",
@@ -54,26 +53,25 @@ impl Emitter for SarifEmitter {
 #[derive(Debug, Clone)]
 struct SarifRule<'a> {
     name: &'a str,
-    code: String,
+    code: &'a SecondaryCode,
     linter: &'a str,
     summary: &'a str,
     explanation: Option<&'a str>,
     url: Option<String>,
 }
 
-impl From<NoqaCode> for SarifRule<'_> {
-    fn from(code: NoqaCode) -> Self {
-        let code_str = code.to_string();
+impl<'a> From<&'a SecondaryCode> for SarifRule<'a> {
+    fn from(code: &'a SecondaryCode) -> Self {
         // This is a manual re-implementation of Rule::from_code, but we also want the Linter. This
         // avoids calling Linter::parse_code twice.
-        let (linter, suffix) = Linter::parse_code(&code_str).unwrap();
+        let (linter, suffix) = Linter::parse_code(code).unwrap();
         let rule = linter
             .all_rules()
             .find(|rule| rule.noqa_code().suffix() == suffix)
             .expect("Expected a valid noqa code corresponding to a rule");
         Self {
             name: rule.into(),
-            code: code_str,
+            code,
             linter: linter.name(),
             summary: rule.message_formats()[0],
             explanation: rule.explanation(),
@@ -111,8 +109,8 @@ impl Serialize for SarifRule<'_> {
 }
 
 #[derive(Debug)]
-struct SarifResult {
-    code: Option<NoqaCode>,
+struct SarifResult<'a> {
+    code: Option<&'a SecondaryCode>,
     level: String,
     message: String,
     uri: String,
@@ -122,14 +120,14 @@ struct SarifResult {
     end_column: OneIndexed,
 }
 
-impl SarifResult {
+impl<'a> SarifResult<'a> {
     #[cfg(not(target_arch = "wasm32"))]
-    fn from_message(message: &OldDiagnostic) -> Result<Self> {
+    fn from_message(message: &'a OldDiagnostic) -> Result<Self> {
         let start_location = message.compute_start_location();
         let end_location = message.compute_end_location();
         let path = normalize_path(&*message.filename());
         Ok(Self {
-            code: message.noqa_code(),
+            code: message.secondary_code(),
             level: "error".to_string(),
             message: message.body().to_string(),
             uri: url::Url::from_file_path(&path)
@@ -144,12 +142,12 @@ impl SarifResult {
 
     #[cfg(target_arch = "wasm32")]
     #[expect(clippy::unnecessary_wraps)]
-    fn from_message(message: &OldDiagnostic) -> Result<Self> {
+    fn from_message(message: &'a OldDiagnostic) -> Result<Self> {
         let start_location = message.compute_start_location();
         let end_location = message.compute_end_location();
         let path = normalize_path(&*message.filename());
         Ok(Self {
-            code: message.noqa_code(),
+            code: message.secondary_code(),
             level: "error".to_string(),
             message: message.body().to_string(),
             uri: path.display().to_string(),
@@ -161,7 +159,7 @@ impl SarifResult {
     }
 }
 
-impl Serialize for SarifResult {
+impl Serialize for SarifResult<'_> {
     fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
     where
         S: Serializer,
@@ -184,7 +182,7 @@ impl Serialize for SarifResult {
                     }
                 }
             }],
-            "ruleId": self.code.map(|code| code.to_string()),
+            "ruleId": self.code,
         })
         .serialize(serializer)
     }

crates/ruff_linter/src/message/text.rs

@@ -14,7 +14,7 @@ use crate::Locator;
 use crate::fs::relativize_path;
 use crate::line_width::{IndentWidth, LineWidthBuilder};
 use crate::message::diff::Diff;
-use crate::message::{Emitter, EmitterContext, OldDiagnostic};
+use crate::message::{Emitter, EmitterContext, OldDiagnostic, SecondaryCode};
 use crate::settings::types::UnsafeFixes;
 
 bitflags! {
@@ -151,8 +151,8 @@ impl Display for RuleCodeAndBody<'_> {
             if let Some(fix) = self.message.fix() {
                 // Do not display an indicator for inapplicable fixes
                 if fix.applies(self.unsafe_fixes.required_applicability()) {
-                    if let Some(code) = self.message.noqa_code() {
-                        write!(f, "{} ", code.to_string().red().bold())?;
+                    if let Some(code) = self.message.secondary_code() {
+                        write!(f, "{} ", code.red().bold())?;
                     }
                     return write!(
                         f,
@@ -164,11 +164,11 @@ impl Display for RuleCodeAndBody<'_> {
             }
         }
 
-        if let Some(code) = self.message.noqa_code() {
+        if let Some(code) = self.message.secondary_code() {
             write!(
                 f,
                 "{code} {body}",
-                code = code.to_string().red().bold(),
+                code = code.red().bold(),
                 body = self.message.body(),
             )
         } else {
@@ -254,8 +254,9 @@ impl Display for MessageCodeFrame<'_> {
 
         let label = self
             .message
-            .noqa_code()
-            .map_or_else(String::new, |code| code.to_string());
+            .secondary_code()
+            .map(SecondaryCode::as_str)
+            .unwrap_or_default();
 
         let line_start = self.notebook_index.map_or_else(
             || start_index.get(),
@@ -269,7 +270,7 @@ impl Display for MessageCodeFrame<'_> {
 
         let span = usize::from(source.annotation_range.start())
             ..usize::from(source.annotation_range.end());
-        let annotation = Level::Error.span(span).label(&label);
+        let annotation = Level::Error.span(span).label(label);
         let snippet = Snippet::source(&source.text)
             .line_start(line_start)
             .annotation(annotation)

crates/ruff_linter/src/noqa.rs

@@ -16,9 +16,8 @@ use rustc_hash::FxHashSet;
 
 use crate::Edit;
 use crate::Locator;
-use crate::codes::NoqaCode;
 use crate::fs::relativize_path;
-use crate::message::OldDiagnostic;
+use crate::message::{OldDiagnostic, SecondaryCode};
 use crate::registry::Rule;
 use crate::rule_redirects::get_redirect_target;
 
@@ -106,9 +105,9 @@ impl Codes<'_> {
 
     /// Returns `true` if the string list of `codes` includes `code` (or an alias
     /// thereof).
-    pub(crate) fn includes(&self, needle: NoqaCode) -> bool {
+    pub(crate) fn includes<T: for<'a> PartialEq<&'a str>>(&self, needle: &T) -> bool {
         self.iter()
-            .any(|code| needle == get_redirect_target(code.as_str()).unwrap_or(code.as_str()))
+            .any(|code| *needle == get_redirect_target(code.as_str()).unwrap_or(code.as_str()))
     }
 }
 
@@ -140,48 +139,55 @@ pub(crate) fn rule_is_ignored(
         Ok(Some(NoqaLexerOutput {
             directive: Directive::Codes(codes),
             ..
-        })) => codes.includes(code.noqa_code()),
+        })) => codes.includes(&code.noqa_code()),
         _ => false,
     }
 }
 
 /// A summary of the file-level exemption as extracted from [`FileNoqaDirectives`].
 #[derive(Debug)]
-pub(crate) enum FileExemption<'a> {
+pub(crate) enum FileExemption {
     /// The file is exempt from all rules.
-    All(Vec<&'a NoqaCode>),
+    All(Vec<Rule>),
     /// The file is exempt from the given rules.
-    Codes(Vec<&'a NoqaCode>),
+    Codes(Vec<Rule>),
 }
 
-impl FileExemption<'_> {
-    /// Returns `true` if the file is exempt from the given rule.
-    pub(crate) fn includes(&self, needle: Rule) -> bool {
-        let needle = needle.noqa_code();
+impl FileExemption {
+    /// Returns `true` if the file is exempt from the given rule, as identified by its noqa code.
+    pub(crate) fn contains_secondary_code(&self, needle: &SecondaryCode) -> bool {
         match self {
             FileExemption::All(_) => true,
-            FileExemption::Codes(codes) => codes.iter().any(|code| needle == **code),
+            FileExemption::Codes(codes) => codes.iter().any(|code| *needle == code.noqa_code()),
+        }
+    }
+
+    /// Returns `true` if the file is exempt from the given rule.
+    pub(crate) fn includes(&self, needle: Rule) -> bool {
+        match self {
+            FileExemption::All(_) => true,
+            FileExemption::Codes(codes) => codes.contains(&needle),
         }
     }
 
     /// Returns `true` if the file exemption lists the rule directly, rather than via a blanket
     /// exemption.
     pub(crate) fn enumerates(&self, needle: Rule) -> bool {
-        let needle = needle.noqa_code();
         let codes = match self {
             FileExemption::All(codes) => codes,
             FileExemption::Codes(codes) => codes,
         };
-        codes.iter().any(|code| needle == **code)
+        codes.contains(&needle)
     }
 }
 
-impl<'a> From<&'a FileNoqaDirectives<'a>> for FileExemption<'a> {
+impl<'a> From<&'a FileNoqaDirectives<'a>> for FileExemption {
     fn from(directives: &'a FileNoqaDirectives) -> Self {
         let codes = directives
             .lines()
             .iter()
             .flat_map(|line| &line.matches)
+            .copied()
             .collect();
         if directives
             .lines()
@@ -203,7 +209,7 @@ pub(crate) struct FileNoqaDirectiveLine<'a> {
     /// The blanket noqa directive.
     pub(crate) parsed_file_exemption: Directive<'a>,
     /// The codes that are ignored by the parsed exemptions.
-    pub(crate) matches: Vec<NoqaCode>,
+    pub(crate) matches: Vec<Rule>,
 }
 
 impl Ranged for FileNoqaDirectiveLine<'_> {
@@ -270,7 +276,7 @@ impl<'a> FileNoqaDirectives<'a> {
 
                                 if let Ok(rule) = Rule::from_code(get_redirect_target(code).unwrap_or(code))
                                 {
-                                    Some(rule.noqa_code())
+                                    Some(rule)
                                 } else {
                                     #[expect(deprecated)]
                                     let line = locator.compute_line_index(range.start());
@@ -303,6 +309,10 @@ impl<'a> FileNoqaDirectives<'a> {
     pub(crate) fn lines(&self) -> &[FileNoqaDirectiveLine] {
         &self.0
     }
+
+    pub(crate) fn is_empty(&self) -> bool {
+        self.0.is_empty()
+    }
 }
 
 /// Output of lexing a `noqa` directive.
@@ -830,7 +840,7 @@ fn build_noqa_edits_by_line<'a>(
 
 struct NoqaComment<'a> {
     line: TextSize,
-    code: NoqaCode,
+    code: &'a SecondaryCode,
     directive: Option<&'a Directive<'a>>,
 }
 
@@ -846,24 +856,14 @@ fn find_noqa_comments<'a>(
 
     // Mark any non-ignored diagnostics.
     for message in diagnostics {
-        let Some(code) = message.noqa_code() else {
+        let Some(code) = message.secondary_code() else {
             comments_by_line.push(None);
             continue;
         };
 
-        match &exemption {
-            FileExemption::All(_) => {
-                // If the file is exempted, don't add any noqa directives.
-                comments_by_line.push(None);
-                continue;
-            }
-            FileExemption::Codes(codes) => {
-                // If the diagnostic is ignored by a global exemption, don't add a noqa directive.
-                if codes.contains(&&code) {
-                    comments_by_line.push(None);
-                    continue;
-                }
-            }
+        if exemption.contains_secondary_code(code) {
+            comments_by_line.push(None);
+            continue;
         }
 
         // Is the violation ignored by a `noqa` directive on the parent line?
@@ -921,7 +921,7 @@ fn find_noqa_comments<'a>(
 
 struct NoqaEdit<'a> {
     edit_range: TextRange,
-    noqa_codes: FxHashSet<NoqaCode>,
+    noqa_codes: FxHashSet<&'a SecondaryCode>,
     codes: Option<&'a Codes<'a>>,
     line_ending: LineEnding,
 }
@@ -942,13 +942,13 @@ impl NoqaEdit<'_> {
                     writer,
                     self.noqa_codes
                         .iter()
-                        .map(ToString::to_string)
-                        .chain(codes.iter().map(ToString::to_string))
+                        .map(|code| code.as_str())
+                        .chain(codes.iter().map(Code::as_str))
                         .sorted_unstable(),
                 );
             }
             None => {
-                push_codes(writer, self.noqa_codes.iter().map(ToString::to_string));
+                push_codes(writer, self.noqa_codes.iter().sorted_unstable());
             }
         }
         write!(writer, "{}", self.line_ending.as_str()).unwrap();
@@ -964,7 +964,7 @@ impl Ranged for NoqaEdit<'_> {
 fn generate_noqa_edit<'a>(
     directive: Option<&'a Directive>,
     offset: TextSize,
-    noqa_codes: FxHashSet<NoqaCode>,
+    noqa_codes: FxHashSet<&'a SecondaryCode>,
     locator: &Locator,
     line_ending: LineEnding,
 ) -> Option<NoqaEdit<'a>> {
@@ -1017,7 +1017,7 @@ pub(crate) struct NoqaDirectiveLine<'a> {
     /// The noqa directive.
     pub(crate) directive: Directive<'a>,
     /// The codes that are ignored by the directive.
-    pub(crate) matches: Vec<NoqaCode>,
+    pub(crate) matches: Vec<Rule>,
     /// Whether the directive applies to `range.end`.
     pub(crate) includes_end: bool,
 }
@@ -1142,6 +1142,10 @@ impl<'a> NoqaDirectives<'a> {
     pub(crate) fn lines(&self) -> &[NoqaDirectiveLine] {
         &self.inner
     }
+
+    pub(crate) fn is_empty(&self) -> bool {
+        self.inner.is_empty()
+    }
 }
 
 /// Remaps offsets falling into one of the ranges to instead check for a noqa comment on the

crates/ruff_linter/src/preview.rs

@@ -90,6 +90,11 @@ pub(crate) const fn is_ignore_init_files_in_useless_alias_enabled(
     settings.preview.is_enabled()
 }
 
+// https://github.com/astral-sh/ruff/pull/18572
+pub(crate) const fn is_optional_as_none_in_union_enabled(settings: &LinterSettings) -> bool {
+    settings.preview.is_enabled()
+}
+
 // https://github.com/astral-sh/ruff/pull/18547
 pub(crate) const fn is_invalid_async_mock_access_check_enabled(settings: &LinterSettings) -> bool {
     settings.preview.is_enabled()
@@ -99,3 +104,10 @@ pub(crate) const fn is_invalid_async_mock_access_check_enabled(settings: &Linter
 pub(crate) const fn is_raise_exception_byte_string_enabled(settings: &LinterSettings) -> bool {
     settings.preview.is_enabled()
 }
+
+// https://github.com/astral-sh/ruff/pull/18683
+pub(crate) const fn is_safe_super_call_with_parameters_fix_enabled(
+    settings: &LinterSettings,
+) -> bool {
+    settings.preview.is_enabled()
+}

crates/ruff_linter/src/rules/airflow/rules/moved_to_provider_in_3.rs

@@ -23,12 +23,16 @@ use crate::{FixAvailability, Violation};
 ///
 /// ## Example
 /// ```python
-/// from airflow.auth.managers.fab.fab_auth_manage import FabAuthManager
+/// from airflow.auth.managers.fab.fab_auth_manager import FabAuthManager
+///
+/// fab_auth_manager_app = FabAuthManager().get_fastapi_app()
 /// ```
 ///
 /// Use instead:
 /// ```python
-/// from airflow.providers.fab.auth_manager.fab_auth_manage import FabAuthManager
+/// from airflow.providers.fab.auth_manager.fab_auth_manager import FabAuthManager
+///
+/// fab_auth_manager_app = FabAuthManager().get_fastapi_app()
 /// ```
 #[derive(ViolationMetadata)]
 pub(crate) struct Airflow3MovedToProvider<'a> {

crates/ruff_linter/src/rules/airflow/rules/suggested_to_move_to_provider_in_3.rs

@@ -24,11 +24,31 @@ use ruff_text_size::TextRange;
 /// ## Example
 /// ```python
 /// from airflow.operators.python import PythonOperator
+///
+///
+/// def print_context(ds=None, **kwargs):
+///     print(kwargs)
+///     print(ds)
+///
+///
+/// print_the_context = PythonOperator(
+///     task_id="print_the_context", python_callable=print_context
+/// )
 /// ```
 ///
 /// Use instead:
 /// ```python
 /// from airflow.providers.standard.operators.python import PythonOperator
+///
+///
+/// def print_context(ds=None, **kwargs):
+///     print(kwargs)
+///     print(ds)
+///
+///
+/// print_the_context = PythonOperator(
+///     task_id="print_the_context", python_callable=print_context
+/// )
 /// ```
 #[derive(ViolationMetadata)]
 pub(crate) struct Airflow3SuggestedToMoveToProvider<'a> {

crates/ruff_linter/src/rules/flake8_annotations/rules/definition.rs

@@ -476,12 +476,18 @@ impl Violation for MissingReturnTypeClassMethod {
 /// ## Example
 ///
 /// ```python
+/// from typing import Any
+///
+///
 /// def foo(x: Any): ...
 /// ```
 ///
 /// Use instead:
 ///
 /// ```python
+/// from typing import Any
+///
+///
 /// def foo(x: int): ...
 /// ```
 ///

crates/ruff_linter/src/rules/flake8_async/rules/async_busy_wait.rs

@@ -16,6 +16,8 @@ use crate::rules::flake8_async::helpers::AsyncModule;
 ///
 /// ## Example
 /// ```python
+/// import asyncio
+///
 /// DONE = False
 ///
 ///
@@ -26,6 +28,8 @@ use crate::rules::flake8_async::helpers::AsyncModule;
 ///
 /// Use instead:
 /// ```python
+/// import asyncio
+///
 /// DONE = asyncio.Event()
 ///
 ///

crates/ruff_linter/src/rules/flake8_async/rules/blocking_http_call.rs

@@ -20,12 +20,18 @@ use crate::checkers::ast::Checker;
 ///
 /// ## Example
 /// ```python
+/// import urllib
+///
+///
 /// async def fetch():
 ///     urllib.request.urlopen("https://example.com/foo/bar").read()
 /// ```
 ///
 /// Use instead:
 /// ```python
+/// import aiohttp
+///
+///
 /// async def fetch():
 ///     async with aiohttp.ClientSession() as session:
 ///         async with session.get("https://example.com/foo/bar") as resp:

crates/ruff_linter/src/rules/flake8_async/rules/blocking_process_invocation.rs

@@ -21,12 +21,18 @@ use crate::checkers::ast::Checker;
 ///
 /// ## Example
 /// ```python
+/// import os
+///
+///
 /// async def foo():
 ///     os.popen(cmd)
 /// ```
 ///
 /// Use instead:
 /// ```python
+/// import asyncio
+///
+///
 /// async def foo():
 ///     asyncio.create_subprocess_shell(cmd)
 /// ```
@@ -54,12 +60,18 @@ impl Violation for CreateSubprocessInAsyncFunction {
 ///
 /// ## Example
 /// ```python
+/// import subprocess
+///
+///
 /// async def foo():
 ///     subprocess.run(cmd)
 /// ```
 ///
 /// Use instead:
 /// ```python
+/// import asyncio
+///
+///
 /// async def foo():
 ///     asyncio.create_subprocess_shell(cmd)
 /// ```
@@ -87,12 +99,19 @@ impl Violation for RunProcessInAsyncFunction {
 ///
 /// ## Example
 /// ```python
+/// import os
+///
+///
 /// async def foo():
 ///     os.waitpid(0)
 /// ```
 ///
 /// Use instead:
 /// ```python
+/// import asyncio
+/// import os
+///
+///
 /// def wait_for_process():
 ///     os.waitpid(0)
 ///

crates/ruff_linter/src/rules/flake8_async/rules/blocking_sleep.rs

@@ -19,12 +19,18 @@ use crate::checkers::ast::Checker;
 ///
 /// ## Example
 /// ```python
+/// import time
+///
+///
 /// async def fetch():
 ///     time.sleep(1)
 /// ```
 ///
 /// Use instead:
 /// ```python
+/// import asyncio
+///
+///
 /// async def fetch():
 ///     await asyncio.sleep(1)
 /// ```

crates/ruff_linter/src/rules/flake8_async/rules/cancel_scope_no_checkpoint.rs

@@ -21,6 +21,9 @@ use crate::rules::flake8_async::helpers::MethodName;
 ///
 /// ## Example
 /// ```python
+/// import asyncio
+///
+///
 /// async def func():
 ///     async with asyncio.timeout(2):
 ///         do_something()
@@ -28,6 +31,9 @@ use crate::rules::flake8_async::helpers::MethodName;
 ///
 /// Use instead:
 /// ```python
+/// import asyncio
+///
+///
 /// async def func():
 ///     async with asyncio.timeout(2):
 ///         do_something()

crates/ruff_linter/src/rules/flake8_async/rules/sync_call.rs

@@ -18,12 +18,18 @@ use crate::{Edit, Fix, FixAvailability, Violation};
 ///
 /// ## Example
 /// ```python
+/// import trio
+///
+///
 /// async def double_sleep(x):
 ///     trio.sleep(2 * x)
 /// ```
 ///
 /// Use instead:
 /// ```python
+/// import trio
+///
+///
 /// async def double_sleep(x):
 ///     await trio.sleep(2 * x)
 /// ```

crates/ruff_linter/src/rules/flake8_bandit/rules/flask_debug_true.rs

@@ -18,7 +18,7 @@ use crate::checkers::ast::Checker;
 ///
 /// ## Example
 /// ```python
-/// import flask
+/// from flask import Flask
 ///
 /// app = Flask()
 ///
@@ -27,7 +27,9 @@ use crate::checkers::ast::Checker;
 ///
 /// Use instead:
 /// ```python
-/// import flask
+/// import os
+///
+/// from flask import Flask
 ///
 /// app = Flask()
 ///

crates/ruff_linter/src/rules/flake8_bandit/rules/shell_injection.rs

@@ -108,10 +108,10 @@ impl Violation for SubprocessWithoutShellEqualsTrue {
 ///
 /// ## Example
 /// ```python
-/// import subprocess
+/// import my_custom_subprocess
 ///
 /// user_input = input("Enter a command: ")
-/// subprocess.run(user_input, shell=True)
+/// my_custom_subprocess.run(user_input, shell=True)
 /// ```
 ///
 /// ## References
@@ -265,14 +265,14 @@ impl Violation for StartProcessWithPartialPath {
 /// ```python
 /// import subprocess
 ///
-/// subprocess.Popen(["chmod", "777", "*.py"])
+/// subprocess.Popen(["chmod", "777", "*.py"], shell=True)
 /// ```
 ///
 /// Use instead:
 /// ```python
 /// import subprocess
 ///
-/// subprocess.Popen(["chmod", "777", "main.py"])
+/// subprocess.Popen(["chmod", "777", "main.py"], shell=True)
 /// ```
 ///
 /// ## References

crates/ruff_linter/src/rules/flake8_bugbear/rules/batched_without_explicit_strict.rs

@@ -20,16 +20,22 @@ use crate::{FixAvailability, Violation};
 ///
 /// ## Example
 /// ```python
+/// import itertools
+///
 /// itertools.batched(iterable, n)
 /// ```
 ///
 /// Use instead if the batches must be of uniform length:
 /// ```python
+/// import itertools
+///
 /// itertools.batched(iterable, n, strict=True)
 /// ```
 ///
 /// Or if the batches can be of non-uniform length:
 /// ```python
+/// import itertools
+///
 /// itertools.batched(iterable, n, strict=False)
 /// ```
 ///

crates/ruff_linter/src/rules/flake8_bugbear/rules/no_explicit_stacklevel.rs

@@ -20,11 +20,15 @@ use crate::{checkers::ast::Checker, fix::edits::add_argument};
 ///
 /// ## Example
 /// ```python
+/// import warnings
+///
 /// warnings.warn("This is a warning")
 /// ```
 ///
 /// Use instead:
 /// ```python
+/// import warnings
+///
 /// warnings.warn("This is a warning", stacklevel=2)
 /// ```
 ///

crates/ruff_linter/src/rules/flake8_comprehensions/mod.rs

@@ -24,6 +24,7 @@ mod tests {
     #[test_case(Rule::UnnecessaryComprehensionInCall, Path::new("C419_2.py"))]
     #[test_case(Rule::UnnecessaryDictComprehensionForIterable, Path::new("C420.py"))]
     #[test_case(Rule::UnnecessaryDictComprehensionForIterable, Path::new("C420_1.py"))]
+    #[test_case(Rule::UnnecessaryDictComprehensionForIterable, Path::new("C420_2.py"))]
     #[test_case(Rule::UnnecessaryDoubleCastOrProcess, Path::new("C414.py"))]
     #[test_case(Rule::UnnecessaryGeneratorDict, Path::new("C402.py"))]
     #[test_case(Rule::UnnecessaryGeneratorList, Path::new("C400.py"))]

crates/ruff_linter/src/rules/flake8_comprehensions/rules/unnecessary_dict_comprehension_for_iterable.rs

@@ -7,6 +7,7 @@ use ruff_python_ast::{self as ast, Arguments, Comprehension, Expr, ExprCall, Exp
 use ruff_text_size::{Ranged, TextRange};
 
 use crate::checkers::ast::Checker;
+use crate::fix::edits::pad_start;
 use crate::{Edit, Fix, FixAvailability, Violation};
 
 /// ## What it does
@@ -136,12 +137,16 @@ pub(crate) fn unnecessary_dict_comprehension_for_iterable(
 
     if checker.semantic().has_builtin_binding("dict") {
         let edit = Edit::range_replacement(
-            checker
-                .generator()
-                .expr(&fix_unnecessary_dict_comprehension(
-                    dict_comp.value.as_ref(),
-                    generator,
-                )),
+            pad_start(
+                checker
+                    .generator()
+                    .expr(&fix_unnecessary_dict_comprehension(
+                        dict_comp.value.as_ref(),
+                        generator,
+                    )),
+                dict_comp.start(),
+                checker.locator(),
+            ),
             dict_comp.range(),
         );
         diagnostic.set_fix(Fix::applicable_edit(

crates/ruff_linter/src/rules/flake8_comprehensions/snapshots/ruff_linter__rules__flake8_comprehensions__tests__C420_C420_2.py.snap

@@ -0,0 +1,16 @@
+---
+source: crates/ruff_linter/src/rules/flake8_comprehensions/mod.rs
+---
+C420_2.py:1:7: C420 [*] Unnecessary dict comprehension for iterable; use `dict.fromkeys` instead
+  |
+1 | foo or{x: None for x in bar}
+  |       ^^^^^^^^^^^^^^^^^^^^^^ C420
+  |
+  = help: Replace with `dict.fromkeys(iterable, value)`)
+
+ℹ Safe fix
+1   |-foo or{x: None for x in bar}
+  1 |+foo or dict.fromkeys(bar)
+2 2 | 
+3 3 | 
+4 4 | # C420 fix must make sure to insert a leading space if needed,

crates/ruff_linter/src/rules/flake8_datetimez/rules/call_date_today.rs

@@ -24,7 +24,7 @@ use crate::checkers::ast::Checker;
 /// ```python
 /// import datetime
 ///
-/// datetime.datetime.today()
+/// datetime.date.today()
 /// ```
 ///
 /// Use instead:

crates/ruff_linter/src/rules/flake8_datetimez/rules/datetime_min_max.rs

@@ -18,19 +18,25 @@ use crate::checkers::ast::Checker;
 /// unexpectedly, as in:
 ///
 /// ```python
+/// import datetime
+///
 /// # Timezone: UTC-14
-/// datetime.min.timestamp()  # ValueError: year 0 is out of range
-/// datetime.max.timestamp()  # ValueError: year 10000 is out of range
+/// datetime.datetime.min.timestamp()  # ValueError: year 0 is out of range
+/// datetime.datetime.max.timestamp()  # ValueError: year 10000 is out of range
 /// ```
 ///
 /// ## Example
 /// ```python
-/// datetime.max
+/// import datetime
+///
+/// datetime.datetime.max
 /// ```
 ///
 /// Use instead:
 /// ```python
-/// datetime.max.replace(tzinfo=datetime.UTC)
+/// import datetime
+///
+/// datetime.datetime.max.replace(tzinfo=datetime.UTC)
 /// ```
 #[derive(ViolationMetadata)]
 pub(crate) struct DatetimeMinMax {

crates/ruff_linter/src/rules/flake8_executable/mod.rs

@@ -22,6 +22,8 @@ mod tests {
     #[test_case(Path::new("EXE002_3.py"))]
     #[test_case(Path::new("EXE003.py"))]
     #[test_case(Path::new("EXE003_uv.py"))]
+    #[test_case(Path::new("EXE003_uv_tool.py"))]
+    #[test_case(Path::new("EXE003_uvx.py"))]
     #[test_case(Path::new("EXE004_1.py"))]
     #[test_case(Path::new("EXE004_2.py"))]
     #[test_case(Path::new("EXE004_3.py"))]

crates/ruff_linter/src/rules/flake8_executable/rules/shebang_missing_python.rs

@@ -47,7 +47,12 @@ pub(crate) fn shebang_missing_python(
     shebang: &ShebangDirective,
     context: &LintContext,
 ) {
-    if shebang.contains("python") || shebang.contains("pytest") || shebang.contains("uv run") {
+    if shebang.contains("python")
+        || shebang.contains("pytest")
+        || shebang.contains("uv run")
+        || shebang.contains("uvx")
+        || shebang.contains("uv tool run")
+    {
         return;
     }
 

crates/ruff_linter/src/rules/flake8_executable/snapshots/ruff_linter__rules__flake8_executable__tests__EXE003_uv_tool.py.snap

@@ -0,0 +1,4 @@
+---
+source: crates/ruff_linter/src/rules/flake8_executable/mod.rs
+---
+

crates/ruff_linter/src/rules/flake8_executable/snapshots/ruff_linter__rules__flake8_executable__tests__EXE003_uvx.py.snap

@@ -0,0 +1,4 @@
+---
+source: crates/ruff_linter/src/rules/flake8_executable/mod.rs
+---
+

crates/ruff_linter/src/rules/flake8_pyi/mod.rs

@@ -11,6 +11,7 @@ mod tests {
 
     use crate::registry::Rule;
     use crate::rules::pep8_naming;
+    use crate::settings::types::PreviewMode;
     use crate::test::test_path;
     use crate::{assert_diagnostics, settings};
 
@@ -172,4 +173,23 @@ mod tests {
         assert_diagnostics!(snapshot, diagnostics);
         Ok(())
     }
+
+    #[test_case(Rule::DuplicateUnionMember, Path::new("PYI016.py"))]
+    #[test_case(Rule::DuplicateUnionMember, Path::new("PYI016.pyi"))]
+    fn preview_rules(rule_code: Rule, path: &Path) -> Result<()> {
+        let snapshot = format!(
+            "preview__{}_{}",
+            rule_code.noqa_code(),
+            path.to_string_lossy()
+        );
+        let diagnostics = test_path(
+            Path::new("flake8_pyi").join(path).as_path(),
+            &settings::LinterSettings {
+                preview: PreviewMode::Enabled,
+                ..settings::LinterSettings::for_rule(rule_code)
+            },
+        )?;
+        assert_diagnostics!(snapshot, diagnostics);
+        Ok(())
+    }
 }

crates/ruff_linter/src/rules/flake8_pyi/rules/any_eq_ne_annotation.rs

@@ -28,8 +28,10 @@ use crate::{AlwaysFixableViolation, Edit, Fix};
 /// ## Example
 ///
 /// ```pyi
+/// from typing import Any
+///
 /// class Foo:
-///     def __eq__(self, obj: typing.Any) -> bool: ...
+///     def __eq__(self, obj: Any) -> bool: ...
 /// ```
 ///
 /// Use instead:

crates/ruff_linter/src/rules/flake8_pyi/rules/duplicate_literal_member.rs

@@ -19,11 +19,15 @@ use crate::{AlwaysFixableViolation, Applicability, Edit, Fix};
 ///
 /// ## Example
 /// ```python
+/// from typing import Literal
+///
 /// foo: Literal["a", "b", "a"]
 /// ```
 ///
 /// Use instead:
 /// ```python
+/// from typing import Literal
+///
 /// foo: Literal["a", "b"]
 /// ```
 ///

crates/ruff_linter/src/rules/flake8_pyi/rules/duplicate_union_member.rs

@@ -1,17 +1,16 @@
-use std::collections::HashSet;
-
 use rustc_hash::FxHashSet;
+use std::collections::HashSet;
 
 use ruff_macros::{ViolationMetadata, derive_message_formats};
 use ruff_python_ast::comparable::ComparableExpr;
-use ruff_python_ast::{Expr, ExprBinOp, Operator, PythonVersion};
-use ruff_python_semantic::analyze::typing::traverse_union;
-use ruff_text_size::{Ranged, TextRange};
-
-use crate::checkers::ast::Checker;
-use crate::{Applicability, Edit, Fix, FixAvailability, Violation};
+use ruff_python_ast::{AtomicNodeIndex, Expr, ExprBinOp, ExprNoneLiteral, Operator, PythonVersion};
+use ruff_python_semantic::analyze::typing::{traverse_union, traverse_union_and_optional};
+use ruff_text_size::{Ranged, TextRange, TextSize};
 
 use super::generate_union_fix;
+use crate::checkers::ast::Checker;
+use crate::preview::is_optional_as_none_in_union_enabled;
+use crate::{Applicability, Edit, Fix, FixAvailability, Violation};
 
 /// ## What it does
 /// Checks for duplicate union members.
@@ -71,21 +70,35 @@ pub(crate) fn duplicate_union_member<'a>(checker: &Checker, expr: &'a Expr) {
             union_type = UnionKind::PEP604;
         }
 
+        let virtual_expr = if is_optional_as_none_in_union_enabled(checker.settings())
+            && is_optional_type(checker, expr)
+        {
+            // If the union member is an `Optional`, add a virtual `None` literal.
+            &VIRTUAL_NONE_LITERAL
+        } else {
+            expr
+        };
+
         // If we've already seen this union member, raise a violation.
-        if seen_nodes.insert(expr.into()) {
-            unique_nodes.push(expr);
+        if seen_nodes.insert(virtual_expr.into()) {
+            unique_nodes.push(virtual_expr);
         } else {
             diagnostics.push(checker.report_diagnostic(
                 DuplicateUnionMember {
-                    duplicate_name: checker.generator().expr(expr),
+                    duplicate_name: checker.generator().expr(virtual_expr),
                 },
+                // Use the real expression's range for diagnostics,
                 expr.range(),
             ));
         }
     };
 
     // Traverse the union, collect all diagnostic members
-    traverse_union(&mut check_for_duplicate_members, checker.semantic(), expr);
+    if is_optional_as_none_in_union_enabled(checker.settings()) {
+        traverse_union_and_optional(&mut check_for_duplicate_members, checker.semantic(), expr);
+    } else {
+        traverse_union(&mut check_for_duplicate_members, checker.semantic(), expr);
+    }
 
     if diagnostics.is_empty() {
         return;
@@ -178,3 +191,12 @@ fn generate_pep604_fix(
         applicability,
     )
 }
+
+static VIRTUAL_NONE_LITERAL: Expr = Expr::NoneLiteral(ExprNoneLiteral {
+    node_index: AtomicNodeIndex::dummy(),
+    range: TextRange::new(TextSize::new(0), TextSize::new(0)),
+});
+
+fn is_optional_type(checker: &Checker, expr: &Expr) -> bool {
+    checker.semantic().match_typing_expr(expr, "Optional")
+}

crates/ruff_linter/src/rules/flake8_pyi/rules/generic_not_last_base_class.rs

@@ -21,27 +21,47 @@ use crate::{Fix, FixAvailability, Violation};
 ///
 /// For example:
 /// ```python
+/// from collections.abc import Container, Iterable, Sized
+/// from typing import Generic, TypeVar
+///
+///
+/// T = TypeVar("T")
+/// K = TypeVar("K")
+/// V = TypeVar("V")
+///
+///
 /// class LinkedList(Generic[T], Sized):
 ///     def push(self, item: T) -> None:
 ///         self._items.append(item)
 ///
+///
 /// class MyMapping(
 ///     Generic[K, V],
-///     Iterable[Tuple[K, V]],
-///     Container[Tuple[K, V]],
+///     Iterable[tuple[K, V]],
+///     Container[tuple[K, V]],
 /// ):
 ///     ...
 /// ```
 ///
 /// Use instead:
 /// ```python
+/// from collections.abc import Container, Iterable, Sized
+/// from typing import Generic, TypeVar
+///
+///
+/// T = TypeVar("T")
+/// K = TypeVar("K")
+/// V = TypeVar("V")
+///
+///
 /// class LinkedList(Sized, Generic[T]):
 ///     def push(self, item: T) -> None:
 ///         self._items.append(item)
 ///
+///
 /// class MyMapping(
-///     Iterable[Tuple[K, V]],
-///     Container[Tuple[K, V]],
+///     Iterable[tuple[K, V]],
+///     Container[tuple[K, V]],
 ///     Generic[K, V],
 /// ):
 ///     ...

crates/ruff_linter/src/rules/flake8_pyi/rules/simple_defaults.rs

@@ -75,7 +75,7 @@ impl AlwaysFixableViolation for TypedArgumentDefaultInStub {
 /// ## Example
 ///
 /// ```pyi
-/// def foo(arg=[]) -> None: ...
+/// def foo(arg=bar()) -> None: ...
 /// ```
 ///
 /// Use instead:
@@ -120,7 +120,7 @@ impl AlwaysFixableViolation for ArgumentDefaultInStub {
 ///
 /// ## Example
 /// ```pyi
-/// foo: str = "..."
+/// foo: str = bar()
 /// ```
 ///
 /// Use instead:

crates/ruff_linter/src/rules/flake8_pyi/rules/type_alias_naming.rs

@@ -14,11 +14,15 @@ use crate::checkers::ast::Checker;
 ///
 /// ## Example
 /// ```pyi
+/// from typing import TypeAlias
+///
 /// type_alias_name: TypeAlias = int
 /// ```
 ///
 /// Use instead:
 /// ```pyi
+/// from typing import TypeAlias
+///
 /// TypeAliasName: TypeAlias = int
 /// ```
 #[derive(ViolationMetadata)]

crates/ruff_linter/src/rules/flake8_pyi/snapshots/ruff_linter__rules__flake8_pyi__tests__PYI016_PYI016.py.snap

@@ -914,4 +914,79 @@ PYI016.py:115:23: PYI016 [*] Duplicate union member `int`
     115 |+field35: "int | str"  # Error
 116 116 | 
 117 117 | 
-118 118 |
+118 118 | 
+
+PYI016.py:134:45: PYI016 [*] Duplicate union member `typing.Optional[int]`
+    |
+132 | field40: typing.Union[typing.Optional[int], None]
+133 | field41: typing.Optional[typing.Union[int, None]]
+134 | field42: typing.Union[typing.Optional[int], typing.Optional[int]]
+    |                                             ^^^^^^^^^^^^^^^^^^^^ PYI016
+135 | field43: typing.Optional[int] | None
+136 | field44: typing.Optional[int | None]
+    |
+    = help: Remove duplicate union member `typing.Optional[int]`
+
+ℹ Safe fix
+131 131 | # equivalent to int | None
+132 132 | field40: typing.Union[typing.Optional[int], None]
+133 133 | field41: typing.Optional[typing.Union[int, None]]
+134     |-field42: typing.Union[typing.Optional[int], typing.Optional[int]]
+    134 |+field42: typing.Optional[int]
+135 135 | field43: typing.Optional[int] | None
+136 136 | field44: typing.Optional[int | None]
+137 137 | field45: typing.Optional[int] | typing.Optional[int]
+
+PYI016.py:137:33: PYI016 [*] Duplicate union member `typing.Optional[int]`
+    |
+135 | field43: typing.Optional[int] | None
+136 | field44: typing.Optional[int | None]
+137 | field45: typing.Optional[int] | typing.Optional[int]
+    |                                 ^^^^^^^^^^^^^^^^^^^^ PYI016
+138 | # equivalent to int | dict | None
+139 | field46: typing.Union[typing.Optional[int], typing.Optional[dict]]
+    |
+    = help: Remove duplicate union member `typing.Optional[int]`
+
+ℹ Safe fix
+134 134 | field42: typing.Union[typing.Optional[int], typing.Optional[int]]
+135 135 | field43: typing.Optional[int] | None
+136 136 | field44: typing.Optional[int | None]
+137     |-field45: typing.Optional[int] | typing.Optional[int]
+    137 |+field45: typing.Optional[int]
+138 138 | # equivalent to int | dict | None
+139 139 | field46: typing.Union[typing.Optional[int], typing.Optional[dict]]
+140 140 | field47: typing.Optional[int] | typing.Optional[dict]
+
+PYI016.py:143:61: PYI016 [*] Duplicate union member `complex`
+    |
+142 | # avoid reporting twice
+143 | field48: typing.Union[typing.Optional[typing.Union[complex, complex]], complex]
+    |                                                             ^^^^^^^ PYI016
+144 | field49: typing.Optional[complex | complex] | complex
+    |
+    = help: Remove duplicate union member `complex`
+
+ℹ Safe fix
+140 140 | field47: typing.Optional[int] | typing.Optional[dict]
+141 141 | 
+142 142 | # avoid reporting twice
+143     |-field48: typing.Union[typing.Optional[typing.Union[complex, complex]], complex]
+    143 |+field48: typing.Union[typing.Optional[complex], complex]
+144 144 | field49: typing.Optional[complex | complex] | complex
+
+PYI016.py:144:36: PYI016 [*] Duplicate union member `complex`
+    |
+142 | # avoid reporting twice
+143 | field48: typing.Union[typing.Optional[typing.Union[complex, complex]], complex]
+144 | field49: typing.Optional[complex | complex] | complex
+    |                                    ^^^^^^^ PYI016
+    |
+    = help: Remove duplicate union member `complex`
+
+ℹ Safe fix
+141 141 | 
+142 142 | # avoid reporting twice
+143 143 | field48: typing.Union[typing.Optional[typing.Union[complex, complex]], complex]
+144     |-field49: typing.Optional[complex | complex] | complex
+    144 |+field49: typing.Optional[complex] | complex

crates/ruff_linter/src/rules/flake8_pyi/snapshots/ruff_linter__rules__flake8_pyi__tests__PYI016_PYI016.pyi.snap

@@ -1,6 +1,5 @@
 ---
 source: crates/ruff_linter/src/rules/flake8_pyi/mod.rs
-snapshot_kind: text
 ---
 PYI016.pyi:7:15: PYI016 [*] Duplicate union member `str`
   |
@@ -883,6 +882,8 @@ PYI016.pyi:113:61: PYI016 [*] Duplicate union member `list[int]`
 112 | # Test case for mixed union type
 113 | field34: typing.Union[list[int], str] | typing.Union[bytes, list[int]]  # Error
     |                                                             ^^^^^^^^^ PYI016
+114 |
+115 | # https://github.com/astral-sh/ruff/issues/18546
     |
     = help: Remove duplicate union member `list[int]`
 
@@ -892,3 +893,81 @@ PYI016.pyi:113:61: PYI016 [*] Duplicate union member `list[int]`
 112 112 | # Test case for mixed union type
 113     |-field34: typing.Union[list[int], str] | typing.Union[bytes, list[int]]  # Error
     113 |+field34: typing.Union[list[int], str, bytes]  # Error
+114 114 | 
+115 115 | # https://github.com/astral-sh/ruff/issues/18546
+116 116 | # Expand Optional[T] to Union[T, None]
+
+PYI016.pyi:125:45: PYI016 [*] Duplicate union member `typing.Optional[int]`
+    |
+123 | field40: typing.Union[typing.Optional[int], None]
+124 | field41: typing.Optional[typing.Union[int, None]]
+125 | field42: typing.Union[typing.Optional[int], typing.Optional[int]]
+    |                                             ^^^^^^^^^^^^^^^^^^^^ PYI016
+126 | field43: typing.Optional[int] | None
+127 | field44: typing.Optional[int | None]
+    |
+    = help: Remove duplicate union member `typing.Optional[int]`
+
+ℹ Safe fix
+122 122 | # equivalent to int | None
+123 123 | field40: typing.Union[typing.Optional[int], None]
+124 124 | field41: typing.Optional[typing.Union[int, None]]
+125     |-field42: typing.Union[typing.Optional[int], typing.Optional[int]]
+    125 |+field42: typing.Optional[int]
+126 126 | field43: typing.Optional[int] | None
+127 127 | field44: typing.Optional[int | None]
+128 128 | field45: typing.Optional[int] | typing.Optional[int]
+
+PYI016.pyi:128:33: PYI016 [*] Duplicate union member `typing.Optional[int]`
+    |
+126 | field43: typing.Optional[int] | None
+127 | field44: typing.Optional[int | None]
+128 | field45: typing.Optional[int] | typing.Optional[int]
+    |                                 ^^^^^^^^^^^^^^^^^^^^ PYI016
+129 | # equivalent to int | dict | None
+130 | field46: typing.Union[typing.Optional[int], typing.Optional[dict]]
+    |
+    = help: Remove duplicate union member `typing.Optional[int]`
+
+ℹ Safe fix
+125 125 | field42: typing.Union[typing.Optional[int], typing.Optional[int]]
+126 126 | field43: typing.Optional[int] | None
+127 127 | field44: typing.Optional[int | None]
+128     |-field45: typing.Optional[int] | typing.Optional[int]
+    128 |+field45: typing.Optional[int]
+129 129 | # equivalent to int | dict | None
+130 130 | field46: typing.Union[typing.Optional[int], typing.Optional[dict]]
+131 131 | field47: typing.Optional[int] | typing.Optional[dict]
+
+PYI016.pyi:134:61: PYI016 [*] Duplicate union member `complex`
+    |
+133 | # avoid reporting twice
+134 | field48: typing.Union[typing.Optional[typing.Union[complex, complex]], complex]
+    |                                                             ^^^^^^^ PYI016
+135 | field49: typing.Optional[complex | complex] | complex
+    |
+    = help: Remove duplicate union member `complex`
+
+ℹ Safe fix
+131 131 | field47: typing.Optional[int] | typing.Optional[dict]
+132 132 | 
+133 133 | # avoid reporting twice
+134     |-field48: typing.Union[typing.Optional[typing.Union[complex, complex]], complex]
+    134 |+field48: typing.Union[typing.Optional[complex], complex]
+135 135 | field49: typing.Optional[complex | complex] | complex
+
+PYI016.pyi:135:36: PYI016 [*] Duplicate union member `complex`
+    |
+133 | # avoid reporting twice
+134 | field48: typing.Union[typing.Optional[typing.Union[complex, complex]], complex]
+135 | field49: typing.Optional[complex | complex] | complex
+    |                                    ^^^^^^^ PYI016
+    |
+    = help: Remove duplicate union member `complex`
+
+ℹ Safe fix
+132 132 | 
+133 133 | # avoid reporting twice
+134 134 | field48: typing.Union[typing.Optional[typing.Union[complex, complex]], complex]
+135     |-field49: typing.Optional[complex | complex] | complex
+    135 |+field49: typing.Optional[complex] | complex