don't do nested bindings inference if we have a declared type

## Summary

Reported in:
https://github.com/astral-sh/ruff/pull/19795#issuecomment-3161981945

If a root expression is reassigned, narrowing on the member should be
invalidated, but there was an oversight in the current implementation.

This PR fixes that, and also removes some unnecessary handling.

## Test Plan

New tests cases in `narrow/conditionals/nested.md`.

.github/CODEOWNERS

@@ -19,6 +19,10 @@
 
 # ty
 /crates/ty* @carljm @MichaReiser @AlexWaygood @sharkdp @dcreager
-/crates/ruff_db/ @carljm @MichaReiser @AlexWaygood @sharkdp @dcreager
+/crates/ruff_db/ @carljm @MichaReiser @sharkdp @dcreager
+/crates/ty_project/ @carljm @MichaReiser @sharkdp @dcreager
+/crates/ty_server/ @carljm @MichaReiser @sharkdp @dcreager
+/crates/ty/ @carljm @MichaReiser @sharkdp @dcreager
+/crates/ty_wasm/ @carljm @MichaReiser @sharkdp @dcreager
 /scripts/ty_benchmark/ @carljm @MichaReiser @AlexWaygood @sharkdp @dcreager
 /crates/ty_python_semantic @carljm @AlexWaygood @sharkdp @dcreager

.github/workflows/build-docker.yml

@@ -63,7 +63,7 @@ jobs:
 
       - name: Extract metadata (tags, labels) for Docker
         id: meta
-        uses: docker/metadata-action@902fa8ec7d6ecbf8d84d538b9b233a880e428804 # v5.7.0
+        uses: docker/metadata-action@c1e51972afc2121e065aed6d45c65596fe445f3f # v5.8.0
         with:
           images: ${{ env.RUFF_BASE_IMG }}
           # Defining this makes sure the org.opencontainers.image.version OCI label becomes the actual release version and not the branch name
@@ -123,7 +123,7 @@ jobs:
 
       - name: Extract metadata (tags, labels) for Docker
         id: meta
-        uses: docker/metadata-action@902fa8ec7d6ecbf8d84d538b9b233a880e428804 # v5.7.0
+        uses: docker/metadata-action@c1e51972afc2121e065aed6d45c65596fe445f3f # v5.8.0
         with:
           images: ${{ env.RUFF_BASE_IMG }}
           # Order is on purpose such that the label org.opencontainers.image.version has the first pattern with the full version
@@ -219,7 +219,7 @@ jobs:
 
       - name: Extract metadata (tags, labels) for Docker
         id: meta
-        uses: docker/metadata-action@902fa8ec7d6ecbf8d84d538b9b233a880e428804 # v5.7.0
+        uses: docker/metadata-action@c1e51972afc2121e065aed6d45c65596fe445f3f # v5.8.0
         # ghcr.io prefers index level annotations
         env:
           DOCKER_METADATA_ANNOTATIONS_LEVELS: index
@@ -266,7 +266,7 @@ jobs:
 
       - name: Extract metadata (tags, labels) for Docker
         id: meta
-        uses: docker/metadata-action@902fa8ec7d6ecbf8d84d538b9b233a880e428804 # v5.7.0
+        uses: docker/metadata-action@c1e51972afc2121e065aed6d45c65596fe445f3f # v5.8.0
         env:
           DOCKER_METADATA_ANNOTATIONS_LEVELS: index
         with:

.github/workflows/ci.yaml

@@ -143,12 +143,12 @@ jobs:
         env:
           MERGE_BASE: ${{ steps.merge_base.outputs.sha }}
         run: |
-          if git diff --quiet "${MERGE_BASE}...HEAD" -- ':**' \
-            ':!**/*.md' \
-            ':crates/ty_python_semantic/resources/mdtest/**/*.md' \
+          # NOTE: Do not exclude all Markdown files here, but rather use
+          # specific exclude patterns like 'docs/**'), because tests for
+          # 'ty' are written in Markdown.
+          if git diff --quiet "${MERGE_BASE}...HEAD" -- \
             ':!docs/**' \
             ':!assets/**' \
-            ':.github/workflows/ci.yaml' \
           ; then
               echo "changed=false" >> "$GITHUB_OUTPUT"
           else
@@ -238,13 +238,13 @@ jobs:
       - name: "Install Rust toolchain"
         run: rustup show
       - name: "Install mold"
-        uses: rui314/setup-mold@85c79d00377f0d32cdbae595a46de6f7c2fa6599 # v1
+        uses: rui314/setup-mold@702b1908b5edf30d71a8d1666b724e0f0c6fa035 # v1
       - name: "Install cargo nextest"
-        uses: taiki-e/install-action@c07504cae06f832dc8de08911c9a9c5cddb0d2d3 # v2.56.13
+        uses: taiki-e/install-action@6064345e6658255e90e9500fdf9a06ab77e6909c # v2.57.6
         with:
           tool: cargo-nextest
       - name: "Install cargo insta"
-        uses: taiki-e/install-action@c07504cae06f832dc8de08911c9a9c5cddb0d2d3 # v2.56.13
+        uses: taiki-e/install-action@6064345e6658255e90e9500fdf9a06ab77e6909c # v2.57.6
         with:
           tool: cargo-insta
       - name: ty mdtests (GitHub annotations)
@@ -296,13 +296,13 @@ jobs:
       - name: "Install Rust toolchain"
         run: rustup show
       - name: "Install mold"
-        uses: rui314/setup-mold@85c79d00377f0d32cdbae595a46de6f7c2fa6599 # v1
+        uses: rui314/setup-mold@702b1908b5edf30d71a8d1666b724e0f0c6fa035 # v1
       - name: "Install cargo nextest"
-        uses: taiki-e/install-action@c07504cae06f832dc8de08911c9a9c5cddb0d2d3 # v2.56.13
+        uses: taiki-e/install-action@6064345e6658255e90e9500fdf9a06ab77e6909c # v2.57.6
         with:
           tool: cargo-nextest
       - name: "Install cargo insta"
-        uses: taiki-e/install-action@c07504cae06f832dc8de08911c9a9c5cddb0d2d3 # v2.56.13
+        uses: taiki-e/install-action@6064345e6658255e90e9500fdf9a06ab77e6909c # v2.57.6
         with:
           tool: cargo-insta
       - name: "Run tests"
@@ -325,7 +325,7 @@ jobs:
       - name: "Install Rust toolchain"
         run: rustup show
       - name: "Install cargo nextest"
-        uses: taiki-e/install-action@c07504cae06f832dc8de08911c9a9c5cddb0d2d3 # v2.56.13
+        uses: taiki-e/install-action@6064345e6658255e90e9500fdf9a06ab77e6909c # v2.57.6
         with:
           tool: cargo-nextest
       - name: "Run tests"
@@ -381,7 +381,7 @@ jobs:
       - name: "Install Rust toolchain"
         run: rustup show
       - name: "Install mold"
-        uses: rui314/setup-mold@85c79d00377f0d32cdbae595a46de6f7c2fa6599 # v1
+        uses: rui314/setup-mold@702b1908b5edf30d71a8d1666b724e0f0c6fa035 # v1
       - name: "Build"
         run: cargo build --release --locked
 
@@ -406,7 +406,7 @@ jobs:
           MSRV: ${{ steps.msrv.outputs.value }}
         run: rustup default "${MSRV}"
       - name: "Install mold"
-        uses: rui314/setup-mold@85c79d00377f0d32cdbae595a46de6f7c2fa6599 # v1
+        uses: rui314/setup-mold@702b1908b5edf30d71a8d1666b724e0f0c6fa035 # v1
       - name: "Build tests"
         shell: bash
         env:
@@ -429,7 +429,7 @@ jobs:
       - name: "Install Rust toolchain"
         run: rustup show
       - name: "Install cargo-binstall"
-        uses: cargo-bins/cargo-binstall@8aac5aa2bf0dfaa2863eccad9f43c68fe40e5ec8 # v1.14.1
+        uses: cargo-bins/cargo-binstall@dd6a0ac24caa1243d18df0f770b941e990e8facc # v1.14.3
         with:
           tool: cargo-fuzz@0.11.2
       - name: "Install cargo-fuzz"
@@ -451,7 +451,7 @@ jobs:
       - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
         with:
           persist-credentials: false
-      - uses: astral-sh/setup-uv@bd01e18f51369d5a26f1651c3cb451d3417e3bba # v6.3.1
+      - uses: astral-sh/setup-uv@e92bafb6253dcd438e0484186d7669ea7a8ca1cc # v6.4.3
       - uses: actions/download-artifact@d3f86a106a0bac45b974a628896c90dbdf5c8093 # v4.3.0
         name: Download Ruff binary to test
         id: download-cached-binary
@@ -652,7 +652,7 @@ jobs:
           branch: ${{ github.event.pull_request.base.ref }}
           workflow: "ci.yaml"
           check_artifacts: true
-      - uses: astral-sh/setup-uv@bd01e18f51369d5a26f1651c3cb451d3417e3bba # v6.3.1
+      - uses: astral-sh/setup-uv@e92bafb6253dcd438e0484186d7669ea7a8ca1cc # v6.4.3
       - name: Fuzz
         env:
           FORCE_COLOR: 1
@@ -682,7 +682,7 @@ jobs:
       - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
         with:
           persist-credentials: false
-      - uses: cargo-bins/cargo-binstall@8aac5aa2bf0dfaa2863eccad9f43c68fe40e5ec8 # v1.14.1
+      - uses: cargo-bins/cargo-binstall@dd6a0ac24caa1243d18df0f770b941e990e8facc # v1.14.3
       - run: cargo binstall --no-confirm cargo-shear
       - run: cargo shear
 
@@ -722,7 +722,7 @@ jobs:
       - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
         with:
           persist-credentials: false
-      - uses: astral-sh/setup-uv@bd01e18f51369d5a26f1651c3cb451d3417e3bba # v6.3.1
+      - uses: astral-sh/setup-uv@e92bafb6253dcd438e0484186d7669ea7a8ca1cc # v6.4.3
       - uses: Swatinem/rust-cache@98c8021b550208e191a6a3145459bfc9fb29c4c0 # v2.8.0
       - uses: actions/setup-node@49933ea5288caeca8642d1e84afbd3f7d6820020 # v4.4.0
         with:
@@ -765,7 +765,7 @@ jobs:
       - name: "Install Rust toolchain"
         run: rustup show
       - name: Install uv
-        uses: astral-sh/setup-uv@bd01e18f51369d5a26f1651c3cb451d3417e3bba # v6.3.1
+        uses: astral-sh/setup-uv@e92bafb6253dcd438e0484186d7669ea7a8ca1cc # v6.4.3
       - name: "Install Insiders dependencies"
         if: ${{ env.MKDOCS_INSIDERS_SSH_KEY_EXISTS == 'true' }}
         run: uv pip install -r docs/requirements-insiders.txt --system
@@ -897,13 +897,13 @@ jobs:
           persist-credentials: false
 
       - uses: Swatinem/rust-cache@98c8021b550208e191a6a3145459bfc9fb29c4c0 # v2.8.0
-      - uses: astral-sh/setup-uv@bd01e18f51369d5a26f1651c3cb451d3417e3bba # v6.3.1
+      - uses: astral-sh/setup-uv@e92bafb6253dcd438e0484186d7669ea7a8ca1cc # v6.4.3
 
       - name: "Install Rust toolchain"
         run: rustup show
 
       - name: "Install codspeed"
-        uses: taiki-e/install-action@c07504cae06f832dc8de08911c9a9c5cddb0d2d3 # v2.56.13
+        uses: taiki-e/install-action@6064345e6658255e90e9500fdf9a06ab77e6909c # v2.57.6
         with:
           tool: cargo-codspeed
 
@@ -911,7 +911,7 @@ jobs:
         run: cargo codspeed build --features "codspeed,instrumented" --no-default-features -p ruff_benchmark
 
       - name: "Run benchmarks"
-        uses: CodSpeedHQ/action@c28fe9fbe7d57a3da1b7834ae3761c1d8217612d # v3.7.0
+        uses: CodSpeedHQ/action@0b6e7a3d96c9d2a6057e7bcea6b45aaf2f7ce60b # v3.8.0
         with:
           run: cargo codspeed run
           token: ${{ secrets.CODSPEED_TOKEN }}
@@ -930,13 +930,13 @@ jobs:
           persist-credentials: false
 
       - uses: Swatinem/rust-cache@98c8021b550208e191a6a3145459bfc9fb29c4c0 # v2.8.0
-      - uses: astral-sh/setup-uv@bd01e18f51369d5a26f1651c3cb451d3417e3bba # v6.3.1
+      - uses: astral-sh/setup-uv@e92bafb6253dcd438e0484186d7669ea7a8ca1cc # v6.4.3
 
       - name: "Install Rust toolchain"
         run: rustup show
 
       - name: "Install codspeed"
-        uses: taiki-e/install-action@c07504cae06f832dc8de08911c9a9c5cddb0d2d3 # v2.56.13
+        uses: taiki-e/install-action@6064345e6658255e90e9500fdf9a06ab77e6909c # v2.57.6
         with:
           tool: cargo-codspeed
 
@@ -944,7 +944,7 @@ jobs:
         run: cargo codspeed build --features "codspeed,walltime" --no-default-features -p ruff_benchmark
 
       - name: "Run benchmarks"
-        uses: CodSpeedHQ/action@c28fe9fbe7d57a3da1b7834ae3761c1d8217612d # v3.7.0
+        uses: CodSpeedHQ/action@0b6e7a3d96c9d2a6057e7bcea6b45aaf2f7ce60b # v3.8.0
         with:
           run: cargo codspeed run
           token: ${{ secrets.CODSPEED_TOKEN }}

.github/workflows/daily_fuzz.yaml

@@ -34,11 +34,11 @@ jobs:
       - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
         with:
           persist-credentials: false
-      - uses: astral-sh/setup-uv@bd01e18f51369d5a26f1651c3cb451d3417e3bba # v6.3.1
+      - uses: astral-sh/setup-uv@e92bafb6253dcd438e0484186d7669ea7a8ca1cc # v6.4.3
       - name: "Install Rust toolchain"
         run: rustup show
       - name: "Install mold"
-        uses: rui314/setup-mold@85c79d00377f0d32cdbae595a46de6f7c2fa6599 # v1
+        uses: rui314/setup-mold@702b1908b5edf30d71a8d1666b724e0f0c6fa035 # v1
       - uses: Swatinem/rust-cache@98c8021b550208e191a6a3145459bfc9fb29c4c0 # v2.8.0
       - name: Build ruff
         # A debug build means the script runs slower once it gets started,

.github/workflows/mypy_primer.yaml

@@ -38,7 +38,7 @@ jobs:
           persist-credentials: false
 
       - name: Install the latest version of uv
-        uses: astral-sh/setup-uv@bd01e18f51369d5a26f1651c3cb451d3417e3bba # v6.3.1
+        uses: astral-sh/setup-uv@e92bafb6253dcd438e0484186d7669ea7a8ca1cc # v6.4.3
 
       - uses: Swatinem/rust-cache@98c8021b550208e191a6a3145459bfc9fb29c4c0 # v2.8.0
         with:
@@ -81,9 +81,9 @@ jobs:
           persist-credentials: false
 
       - name: Install the latest version of uv
-        uses: astral-sh/setup-uv@bd01e18f51369d5a26f1651c3cb451d3417e3bba # v6.3.1
+        uses: astral-sh/setup-uv@e92bafb6253dcd438e0484186d7669ea7a8ca1cc # v6.4.3
 
-      - uses: Swatinem/rust-cache@9d47c6ad4b02e050fd481d890b2ea34778fd09d6 # v2.7.8
+      - uses: Swatinem/rust-cache@98c8021b550208e191a6a3145459bfc9fb29c4c0 # v2.8.0
         with:
           workspaces: "ruff"
 

.github/workflows/publish-pypi.yml

@@ -22,7 +22,7 @@ jobs:
       id-token: write
     steps:
       - name: "Install uv"
-        uses: astral-sh/setup-uv@bd01e18f51369d5a26f1651c3cb451d3417e3bba # v6.3.1
+        uses: astral-sh/setup-uv@e92bafb6253dcd438e0484186d7669ea7a8ca1cc # v6.4.3
       - uses: actions/download-artifact@d3f86a106a0bac45b974a628896c90dbdf5c8093 # v4.3.0
         with:
           pattern: wheels-*

.github/workflows/sync_typeshed.yaml

@@ -34,6 +34,10 @@ env:
   # and which all three workers push to.
   UPSTREAM_BRANCH: typeshedbot/sync-typeshed
 
+  # The path to the directory that contains the vendored typeshed stubs,
+  # relative to the root of the Ruff repository.
+  VENDORED_TYPESHED: crates/ty_vendored/vendor/typeshed
+
 jobs:
   # Sync typeshed stubs, and sync all docstrings available on Linux.
   # Push the changes to a new branch on the upstream repository.
@@ -61,23 +65,23 @@ jobs:
         run: |
           git config --global user.name typeshedbot
           git config --global user.email '<>'
-      - uses: astral-sh/setup-uv@bd01e18f51369d5a26f1651c3cb451d3417e3bba # v6.3.1
+      - uses: astral-sh/setup-uv@e92bafb6253dcd438e0484186d7669ea7a8ca1cc # v6.4.3
       - name: Sync typeshed stubs
         run: |
-          rm -rf ruff/crates/ty_vendored/vendor/typeshed
-          mkdir ruff/crates/ty_vendored/vendor/typeshed
-          cp typeshed/README.md ruff/crates/ty_vendored/vendor/typeshed
-          cp typeshed/LICENSE ruff/crates/ty_vendored/vendor/typeshed
+          rm -rf "ruff/${VENDORED_TYPESHED}"
+          mkdir "ruff/${VENDORED_TYPESHED}"
+          cp typeshed/README.md "ruff/${VENDORED_TYPESHED}"
+          cp typeshed/LICENSE "ruff/${VENDORED_TYPESHED}"
 
           # The pyproject.toml file is needed by a later job for the black configuration.
           # It's deleted before creating the PR.
-          cp typeshed/pyproject.toml ruff/crates/ty_vendored/vendor/typeshed
+          cp typeshed/pyproject.toml "ruff/${VENDORED_TYPESHED}"
 
-          cp -r typeshed/stdlib ruff/crates/ty_vendored/vendor/typeshed/stdlib
-          rm -rf ruff/crates/ty_vendored/vendor/typeshed/stdlib/@tests
-          git -C typeshed rev-parse HEAD > ruff/crates/ty_vendored/vendor/typeshed/source_commit.txt
+          cp -r typeshed/stdlib "ruff/${VENDORED_TYPESHED}/stdlib"
+          rm -rf "ruff/${VENDORED_TYPESHED}/stdlib/@tests"
+          git -C typeshed rev-parse HEAD > "ruff/${VENDORED_TYPESHED}/source_commit.txt"
           cd ruff
-          git checkout -b typeshedbot/sync-typeshed
+          git checkout -b "${UPSTREAM_BRANCH}"
           git add .
           git commit -m "Sync typeshed. Source commit: https://github.com/python/typeshed/commit/$(git -C ../typeshed rev-parse HEAD)" --allow-empty
       - name: Sync Linux docstrings
@@ -113,7 +117,7 @@ jobs:
         with:
           persist-credentials: true
           ref: ${{ env.UPSTREAM_BRANCH}}
-      - uses: astral-sh/setup-uv@bd01e18f51369d5a26f1651c3cb451d3417e3bba # v6.3.1
+      - uses: astral-sh/setup-uv@e92bafb6253dcd438e0484186d7669ea7a8ca1cc # v6.4.3
       - name: Setup git
         run: |
           git config --global user.name typeshedbot
@@ -151,7 +155,7 @@ jobs:
         with:
           persist-credentials: true
           ref: ${{ env.UPSTREAM_BRANCH}}
-      - uses: astral-sh/setup-uv@bd01e18f51369d5a26f1651c3cb451d3417e3bba # v6.3.1
+      - uses: astral-sh/setup-uv@e92bafb6253dcd438e0484186d7669ea7a8ca1cc # v6.4.3
       - name: Setup git
         run: |
           git config --global user.name typeshedbot
@@ -167,17 +171,17 @@ jobs:
           # consistent with the other typeshed stubs around them.
           # Typeshed formats code using black in their CI, so we just invoke
           # black on the stubs the same way that typeshed does.
-          uvx black crates/ty_vendored/vendor/typeshed/stdlib --config crates/ty_vendored/vendor/typeshed/pyproject.toml || true
+          uvx black "${VENDORED_TYPESHED}/stdlib" --config "${VENDORED_TYPESHED}/pyproject.toml" || true
           git commit -am "Format codemodded docstrings" --allow-empty
 
-          rm crates/ty_vendored/vendor/typeshed/pyproject.toml
+          rm "${VENDORED_TYPESHED}/pyproject.toml"
           git commit -am "Remove pyproject.toml file"
 
           git push
       - name: Create a PR
         if: ${{ success() }}
         run: |
-          gh pr list --repo "$GITHUB_REPOSITORY" --head typeshedbot/sync-typeshed --json id --jq length | grep 1 && exit 0 # exit if there is existing pr
+          gh pr list --repo "${GITHUB_REPOSITORY}" --head "${UPSTREAM_BRANCH}" --json id --jq length | grep 1 && exit 0 # exit if there is existing pr
           gh pr create --title "[ty] Sync vendored typeshed stubs" --body "Close and reopen this PR to trigger CI" --label "ty"
 
   create-issue-on-failure:

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

@@ -33,7 +33,7 @@ jobs:
           persist-credentials: false
 
       - name: Install the latest version of uv
-        uses: astral-sh/setup-uv@bd01e18f51369d5a26f1651c3cb451d3417e3bba # v6.3.1
+        uses: astral-sh/setup-uv@e92bafb6253dcd438e0484186d7669ea7a8ca1cc # v6.4.3
 
       - uses: Swatinem/rust-cache@98c8021b550208e191a6a3145459bfc9fb29c4c0 # v2.8.0
         with:
@@ -64,7 +64,7 @@ jobs:
 
           cd ..
 
-          uv tool install "git+https://github.com/astral-sh/ecosystem-analyzer@f0eec0e549684d8e1d7b8bc3e351202124b63bda"
+          uv tool install "git+https://github.com/astral-sh/ecosystem-analyzer@27dd66d9e397d986ef9c631119ee09556eab8af9"
 
           ecosystem-analyzer \
             --repository ruff \

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

@@ -29,7 +29,7 @@ jobs:
           persist-credentials: false
 
       - name: Install the latest version of uv
-        uses: astral-sh/setup-uv@bd01e18f51369d5a26f1651c3cb451d3417e3bba # v6.3.1
+        uses: astral-sh/setup-uv@e92bafb6253dcd438e0484186d7669ea7a8ca1cc # v6.4.3
 
       - uses: Swatinem/rust-cache@98c8021b550208e191a6a3145459bfc9fb29c4c0 # v2.8.0
         with:
@@ -49,7 +49,7 @@ jobs:
 
           cd ..
 
-          uv tool install "git+https://github.com/astral-sh/ecosystem-analyzer@f0eec0e549684d8e1d7b8bc3e351202124b63bda"
+          uv tool install "git+https://github.com/astral-sh/ecosystem-analyzer@27dd66d9e397d986ef9c631119ee09556eab8af9"
 
           ecosystem-analyzer \
             --verbose \

.github/workflows/typing_conformance.yaml

@@ -0,0 +1,113 @@
+name: Run typing conformance
+
+permissions: {}
+
+on:
+  pull_request:
+    paths:
+      - "crates/ty*/**"
+      - "crates/ruff_db"
+      - "crates/ruff_python_ast"
+      - "crates/ruff_python_parser"
+      - ".github/workflows/typing_conformance.yaml"
+      - ".github/workflows/typing_conformance_comment.yaml"
+      - "Cargo.lock"
+      - "!**.md"
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref_name }}-${{ github.event.pull_request.number || github.sha }}
+  cancel-in-progress: true
+
+env:
+  CARGO_INCREMENTAL: 0
+  CARGO_NET_RETRY: 10
+  CARGO_TERM_COLOR: always
+  RUSTUP_MAX_RETRIES: 10
+  RUST_BACKTRACE: 1
+  CONFORMANCE_SUITE_COMMIT: d4f39b27a4a47aac8b6d4019e1b0b5b3156fabdc
+
+jobs:
+  typing_conformance:
+    name: Compute diagnostic diff
+    runs-on: depot-ubuntu-22.04-32
+    timeout-minutes: 10
+    steps:
+      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+        with:
+          path: ruff
+          fetch-depth: 0
+          persist-credentials: false
+
+      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+        with:
+          repository: python/typing
+          ref: ${{ env.CONFORMANCE_SUITE_COMMIT }}
+          path: typing
+          persist-credentials: false
+
+      - uses: Swatinem/rust-cache@98c8021b550208e191a6a3145459bfc9fb29c4c0 # v2.8.0
+        with:
+          workspaces: "ruff"
+
+      - name: Install Rust toolchain
+        run: rustup show
+
+      - name: Compute diagnostic diff
+        shell: bash
+        run: |
+          RUFF_DIR="$GITHUB_WORKSPACE/ruff"
+
+          # Build the executable for the old and new commit
+          (
+            cd ruff
+
+            echo "new commit"
+            git rev-list --format=%s --max-count=1 "$GITHUB_SHA"
+            cargo build --release --bin ty
+            mv target/release/ty ty-new
+
+            MERGE_BASE="$(git merge-base "$GITHUB_SHA" "origin/$GITHUB_BASE_REF")"
+            git checkout -b old_commit "$MERGE_BASE"
+            echo "old commit (merge base)"
+            git rev-list --format=%s --max-count=1 old_commit
+            cargo build --release --bin ty
+            mv target/release/ty ty-old
+          )
+
+          (
+            cd typing/conformance/tests
+
+            echo "Running ty on old commit (merge base)"
+            "$RUFF_DIR/ty-old" check --color=never --output-format=concise . > "$GITHUB_WORKSPACE/old-output.txt" 2>&1 || true
+
+            echo "Running ty on new commit"
+            "$RUFF_DIR/ty-new" check --color=never --output-format=concise . > "$GITHUB_WORKSPACE/new-output.txt" 2>&1 || true
+          )
+
+          if ! diff -u old-output.txt new-output.txt > typing_conformance_diagnostics.diff; then
+            echo "Differences found between base and PR"
+          else
+            echo "No differences found"
+            touch typing_conformance_diagnostics.diff
+          fi
+
+          echo ${{ github.event.number }} > pr-number
+          echo "${CONFORMANCE_SUITE_COMMIT}" > conformance-suite-commit
+
+      - name: Upload diff
+        uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02 # v4.6.2
+        with:
+          name: typing_conformance_diagnostics_diff
+          path: typing_conformance_diagnostics.diff
+
+      - name: Upload pr-number
+        uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02 # v4.6.2
+        with:
+          name: pr-number
+          path: pr-number
+
+      - name: Upload conformance suite commit
+        uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02 # v4.6.2
+        with:
+          name: conformance-suite-commit
+          path: conformance-suite-commit

.github/workflows/typing_conformance_comment.yaml

@@ -0,0 +1,112 @@
+name: PR comment (typing_conformance)
+
+on: # zizmor: ignore[dangerous-triggers]
+  workflow_run:
+    workflows: [Run typing conformance]
+    types: [completed]
+  workflow_dispatch:
+    inputs:
+      workflow_run_id:
+        description: The typing_conformance workflow that triggers the workflow run
+        required: true
+
+jobs:
+  comment:
+    runs-on: ubuntu-24.04
+    permissions:
+      pull-requests: write
+    steps:
+      - uses: dawidd6/action-download-artifact@20319c5641d495c8a52e688b7dc5fada6c3a9fbc # v8
+        name: Download PR number
+        with:
+          name: pr-number
+          run_id: ${{ github.event.workflow_run.id ||  github.event.inputs.workflow_run_id }}
+          if_no_artifact_found: ignore
+          allow_forks: true
+
+      - name: Parse pull request number
+        id: pr-number
+        run: |
+          if [[ -f pr-number ]]
+          then
+            echo "pr-number=$(<pr-number)" >> "$GITHUB_OUTPUT"
+          fi
+
+      - uses: dawidd6/action-download-artifact@20319c5641d495c8a52e688b7dc5fada6c3a9fbc # v8
+        name: Download typing conformance suite commit
+        with:
+          name: conformance-suite-commit
+          run_id: ${{ github.event.workflow_run.id ||  github.event.inputs.workflow_run_id }}
+          if_no_artifact_found: ignore
+          allow_forks: true
+
+      - uses: dawidd6/action-download-artifact@20319c5641d495c8a52e688b7dc5fada6c3a9fbc # v8
+        name: "Download typing_conformance results"
+        id: download-typing_conformance_diff
+        if: steps.pr-number.outputs.pr-number
+        with:
+          name: typing_conformance_diagnostics_diff
+          workflow: typing_conformance.yaml
+          pr: ${{ steps.pr-number.outputs.pr-number }}
+          path: pr/typing_conformance_diagnostics_diff
+          workflow_conclusion: completed
+          if_no_artifact_found: ignore
+          allow_forks: true
+
+      - name: Generate comment content
+        id: generate-comment
+        if: ${{ steps.download-typing_conformance_diff.outputs.found_artifact == 'true' }}
+        run: |
+          # Guard against malicious typing_conformance results that symlink to a secret
+          # file on this runner
+          if [[ -L pr/typing_conformance_diagnostics_diff/typing_conformance_diagnostics.diff ]]
+          then
+              echo "Error: typing_conformance_diagnostics.diff cannot be a symlink"
+              exit 1
+          fi
+
+          # Note this identifier is used to find the comment to update on
+          # subsequent runs
+          echo '<!-- generated-comment typing_conformance_diagnostics_diff -->' >> comment.txt
+
+          if [[ -f conformance-suite-commit ]]
+          then
+            echo "## Diagnostic diff on [typing conformance tests](https://github.com/python/typing/tree/$(<conformance-suite-commit)/conformance)" >> comment.txt
+          else
+            echo "conformance-suite-commit file not found"
+            echo "## Diagnostic diff on typing conformance tests" >> comment.txt
+          fi
+
+          if [ -s "pr/typing_conformance_diagnostics_diff/typing_conformance_diagnostics.diff" ]; then
+            echo '<details>' >> comment.txt
+            echo '<summary>Changes were detected when running ty on typing conformance tests</summary>' >> comment.txt
+            echo '' >> comment.txt
+            echo '```diff' >> comment.txt
+            cat pr/typing_conformance_diagnostics_diff/typing_conformance_diagnostics.diff >> comment.txt
+            echo '```' >> comment.txt
+            echo '</details>' >> comment.txt
+          else
+            echo 'No changes detected when running ty on typing conformance tests ✅' >> comment.txt
+          fi
+
+          echo 'comment<<EOF' >> "$GITHUB_OUTPUT"
+          cat comment.txt >> "$GITHUB_OUTPUT"
+          echo 'EOF' >> "$GITHUB_OUTPUT"
+
+      - name: Find existing comment
+        uses: peter-evans/find-comment@3eae4d37986fb5a8592848f6a574fdf654e61f9e # v3.1.0
+        if: steps.generate-comment.outcome == 'success'
+        id: find-comment
+        with:
+          issue-number: ${{ steps.pr-number.outputs.pr-number }}
+          comment-author: "github-actions[bot]"
+          body-includes: "<!-- generated-comment typing_conformance_diagnostics_diff -->"
+
+      - name: Create or update comment
+        if: steps.find-comment.outcome == 'success'
+        uses: peter-evans/create-or-update-comment@71345be0265236311c031f5c7866368bd1eff043 # v4
+        with:
+          comment-id: ${{ steps.find-comment.outputs.comment-id }}
+          issue-number: ${{ steps.pr-number.outputs.pr-number }}
+          body-path: comment.txt
+          edit-mode: replace

.pre-commit-config.yaml

@@ -81,10 +81,10 @@ repos:
         pass_filenames: false # This makes it a lot faster
 
   - repo: https://github.com/astral-sh/ruff-pre-commit
-    rev: v0.12.3
+    rev: v0.12.7
     hooks:
       - id: ruff-format
-      - id: ruff
+      - id: ruff-check
         args: [--fix, --exit-non-zero-on-fix]
         types_or: [python, pyi]
         require_serial: true

CHANGELOG.md

@@ -1,5 +1,118 @@
 # Changelog
 
+## 0.12.8
+
+### Preview features
+
+- \[`flake8-use-pathlib`\] Expand `PTH201` to check all `PurePath` subclasses ([#19440](https://github.com/astral-sh/ruff/pull/19440))
+
+### Bug fixes
+
+- \[`flake8-blind-except`\] Change `BLE001` to correctly parse exception tuples ([#19747](https://github.com/astral-sh/ruff/pull/19747))
+- \[`flake8-errmsg`\] Exclude `typing.cast` from `EM101` ([#19656](https://github.com/astral-sh/ruff/pull/19656))
+- \[`flake8-simplify`\] Fix raw string handling in `SIM905` for embedded quotes ([#19591](https://github.com/astral-sh/ruff/pull/19591))
+- \[`flake8-import-conventions`\] Avoid false positives for NFKC-normalized `__debug__` import aliases in `ICN001` ([#19411](https://github.com/astral-sh/ruff/pull/19411))
+- \[`isort`\] Fix syntax error after docstring ending with backslash (`I002`) ([#19505](https://github.com/astral-sh/ruff/pull/19505))
+- \[`pylint`\] Mark `PLC0207` fixes as unsafe when `*args` unpacking is present ([#19679](https://github.com/astral-sh/ruff/pull/19679))
+- \[`pyupgrade`\] Prevent infinite loop with `I002` (`UP010`, `UP035`) ([#19413](https://github.com/astral-sh/ruff/pull/19413))
+- \[`ruff`\] Parenthesize generator expressions in f-strings (`RUF010`) ([#19434](https://github.com/astral-sh/ruff/pull/19434))
+
+### Rule changes
+
+- \[`eradicate`\] Don't flag `pyrefly` pragmas as unused code (`ERA001`) ([#19731](https://github.com/astral-sh/ruff/pull/19731))
+
+### Documentation
+
+- Replace "associative" with "commutative" in docs for `RUF036` ([#19706](https://github.com/astral-sh/ruff/pull/19706))
+- Fix copy and line separator colors in dark mode ([#19630](https://github.com/astral-sh/ruff/pull/19630))
+- Fix link to `typing` documentation ([#19648](https://github.com/astral-sh/ruff/pull/19648))
+- \[`refurb`\] Make more examples error out-of-the-box ([#19695](https://github.com/astral-sh/ruff/pull/19695),[#19673](https://github.com/astral-sh/ruff/pull/19673),[#19672](https://github.com/astral-sh/ruff/pull/19672))
+
+### Other changes
+
+- Include column numbers in GitLab output format ([#19708](https://github.com/astral-sh/ruff/pull/19708))
+- Always expand tabs to four spaces in diagnostics ([#19618](https://github.com/astral-sh/ruff/pull/19618))
+- Update pre-commit's `ruff` id ([#19654](https://github.com/astral-sh/ruff/pull/19654))
+
+## 0.12.7
+
+This is a follow-up release to 0.12.6. Because of an issue in the package metadata, 0.12.6 failed to publish fully to PyPI and has been yanked. Similarly, there is no GitHub release or Git tag for 0.12.6. The contents of the 0.12.7 release are identical to 0.12.6, except for the updated metadata.
+
+## 0.12.6
+
+### Preview features
+
+- \[`flake8-commas`\] Add support for trailing comma checks in type parameter lists (`COM812`, `COM819`) ([#19390](https://github.com/astral-sh/ruff/pull/19390))
+- \[`pylint`\] Implement auto-fix for `missing-maxsplit-arg` (`PLC0207`) ([#19387](https://github.com/astral-sh/ruff/pull/19387))
+- \[`ruff`\] Offer fixes for `RUF039` in more cases ([#19065](https://github.com/astral-sh/ruff/pull/19065))
+
+### Bug fixes
+
+- Support `.pyi` files in ruff analyze graph ([#19611](https://github.com/astral-sh/ruff/pull/19611))
+- \[`flake8-pyi`\] Preserve inline comment in ellipsis removal (`PYI013`) ([#19399](https://github.com/astral-sh/ruff/pull/19399))
+- \[`perflint`\] Ignore rule if target is `global` or `nonlocal` (`PERF401`) ([#19539](https://github.com/astral-sh/ruff/pull/19539))
+- \[`pyupgrade`\] Fix `UP030` to avoid modifying double curly braces in format strings ([#19378](https://github.com/astral-sh/ruff/pull/19378))
+- \[`refurb`\] Ignore decorated functions for `FURB118` ([#19339](https://github.com/astral-sh/ruff/pull/19339))
+- \[`refurb`\] Mark `int` and `bool` cases for `Decimal.from_float` as safe fixes (`FURB164`) ([#19468](https://github.com/astral-sh/ruff/pull/19468))
+- \[`ruff`\] Fix `RUF033` for named default expressions ([#19115](https://github.com/astral-sh/ruff/pull/19115))
+
+### Rule changes
+
+- \[`flake8-blind-except`\] Change `BLE001` to permit `logging.critical(..., exc_info=True)` ([#19520](https://github.com/astral-sh/ruff/pull/19520))
+
+### Performance
+
+- Add support for specifying minimum dots in detected string imports ([#19538](https://github.com/astral-sh/ruff/pull/19538))
+
+## 0.12.5
+
+### Preview features
+
+- \[`flake8-use-pathlib`\] Add autofix for `PTH101`, `PTH104`, `PTH105`, `PTH121` ([#19404](https://github.com/astral-sh/ruff/pull/19404))
+- \[`ruff`\] Support byte strings (`RUF055`) ([#18926](https://github.com/astral-sh/ruff/pull/18926))
+
+### Bug fixes
+
+- Fix `unreachable` panic in parser ([#19183](https://github.com/astral-sh/ruff/pull/19183))
+- \[`flake8-pyi`\] Skip fix if all `Union` members are `None` (`PYI016`) ([#19416](https://github.com/astral-sh/ruff/pull/19416))
+- \[`perflint`\] Parenthesize generator expressions (`PERF401`) ([#19325](https://github.com/astral-sh/ruff/pull/19325))
+- \[`pylint`\] Handle empty comments after line continuation (`PLR2044`) ([#19405](https://github.com/astral-sh/ruff/pull/19405))
+
+### Rule changes
+
+- \[`pep8-naming`\] Fix `N802` false positives for `CGIHTTPRequestHandler` and `SimpleHTTPRequestHandler` ([#19432](https://github.com/astral-sh/ruff/pull/19432))
+
+## 0.12.4
+
+### Preview features
+
+- \[`flake8-type-checking`, `pyupgrade`, `ruff`\] Add `from __future__ import annotations` when it would allow new fixes (`TC001`, `TC002`, `TC003`, `UP037`, `RUF013`) ([#19100](https://github.com/astral-sh/ruff/pull/19100))
+- \[`flake8-use-pathlib`\] Add autofix for `PTH109` ([#19245](https://github.com/astral-sh/ruff/pull/19245))
+- \[`pylint`\] Detect indirect `pathlib.Path` usages for `unspecified-encoding` (`PLW1514`) ([#19304](https://github.com/astral-sh/ruff/pull/19304))
+
+### Bug fixes
+
+- \[`flake8-bugbear`\] Fix `B017` false negatives for keyword exception arguments ([#19217](https://github.com/astral-sh/ruff/pull/19217))
+- \[`flake8-use-pathlib`\] Fix false negative on direct `Path()` instantiation (`PTH210`) ([#19388](https://github.com/astral-sh/ruff/pull/19388))
+- \[`flake8-django`\] Fix `DJ008` false positive for abstract models with type-annotated `abstract` field ([#19221](https://github.com/astral-sh/ruff/pull/19221))
+- \[`isort`\] Fix `I002` import insertion after docstring with multiple string statements ([#19222](https://github.com/astral-sh/ruff/pull/19222))
+- \[`isort`\] Treat form feed as valid whitespace before a semicolon ([#19343](https://github.com/astral-sh/ruff/pull/19343))
+- \[`pydoclint`\] Fix `SyntaxError` from fixes with line continuations (`D201`, `D202`) ([#19246](https://github.com/astral-sh/ruff/pull/19246))
+- \[`refurb`\] `FURB164` fix should validate arguments and should usually be marked unsafe ([#19136](https://github.com/astral-sh/ruff/pull/19136))
+
+### Rule changes
+
+- \[`flake8-use-pathlib`\] Skip single dots for `invalid-pathlib-with-suffix` (`PTH210`) on versions >= 3.14 ([#19331](https://github.com/astral-sh/ruff/pull/19331))
+- \[`pep8_naming`\] Avoid false positives on standard library functions with uppercase names (`N802`) ([#18907](https://github.com/astral-sh/ruff/pull/18907))
+- \[`pycodestyle`\] Handle brace escapes for t-strings in logical lines ([#19358](https://github.com/astral-sh/ruff/pull/19358))
+- \[`pylint`\] Extend invalid string character rules to include t-strings ([#19355](https://github.com/astral-sh/ruff/pull/19355))
+- \[`ruff`\] Allow `strict` kwarg when checking for `starmap-zip` (`RUF058`) in Python 3.14+ ([#19333](https://github.com/astral-sh/ruff/pull/19333))
+
+### Documentation
+
+- \[`flake8-type-checking`\] Make `TC010` docs example more realistic ([#19356](https://github.com/astral-sh/ruff/pull/19356))
+- Make more documentation examples error out-of-the-box ([#19288](https://github.com/astral-sh/ruff/pull/19288),[#19272](https://github.com/astral-sh/ruff/pull/19272),[#19291](https://github.com/astral-sh/ruff/pull/19291),[#19296](https://github.com/astral-sh/ruff/pull/19296),[#19292](https://github.com/astral-sh/ruff/pull/19292),[#19295](https://github.com/astral-sh/ruff/pull/19295),[#19297](https://github.com/astral-sh/ruff/pull/19297),[#19309](https://github.com/astral-sh/ruff/pull/19309))
+
 ## 0.12.3
 
 ### Preview features

Cargo.toml

@@ -23,6 +23,7 @@ ruff_graph = { path = "crates/ruff_graph" }
 ruff_index = { path = "crates/ruff_index" }
 ruff_linter = { path = "crates/ruff_linter" }
 ruff_macros = { path = "crates/ruff_macros" }
+ruff_memory_usage = { path = "crates/ruff_memory_usage" }
 ruff_notebook = { path = "crates/ruff_notebook" }
 ruff_options_metadata = { path = "crates/ruff_options_metadata" }
 ruff_python_ast = { path = "crates/ruff_python_ast" }
@@ -40,6 +41,7 @@ ruff_text_size = { path = "crates/ruff_text_size" }
 ruff_workspace = { path = "crates/ruff_workspace" }
 
 ty = { path = "crates/ty" }
+ty_combine = { path = "crates/ty_combine" }
 ty_ide = { path = "crates/ty_ide" }
 ty_project = { path = "crates/ty_project", default-features = false }
 ty_python_semantic = { path = "crates/ty_python_semantic" }
@@ -57,6 +59,9 @@ assert_fs = { version = "1.1.0" }
 argfile = { version = "0.2.0" }
 bincode = { version = "2.0.0" }
 bitflags = { version = "2.5.0" }
+bitvec = { version = "1.0.1", default-features = false, features = [
+    "alloc",
+] }
 bstr = { version = "1.9.1" }
 cachedir = { version = "0.3.1" }
 camino = { version = "1.1.7" }
@@ -70,7 +75,7 @@ console_error_panic_hook = { version = "0.1.7" }
 console_log = { version = "1.0.0" }
 countme = { version = "3.0.1" }
 compact_str = "0.9.0"
-criterion = { version = "0.6.0", default-features = false }
+criterion = { version = "0.7.0", default-features = false }
 crossbeam = { version = "0.8.4" }
 dashmap = { version = "6.0.1" }
 dir-test = { version = "0.4.0" }
@@ -80,7 +85,7 @@ 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 = [
+get-size2 = { version = "0.6.2", features = [
     "derive",
     "smallvec",
     "hashbrown",
@@ -138,7 +143,12 @@ 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", rev = "fc00eba89e5dcaa5edba51c41aa5f309b5cb126b" }
+salsa = { git = "https://github.com/salsa-rs/salsa.git", rev = "b121ee46c4483ba74c19e933a3522bd548eb7343", default-features = false, features = [
+    "compact_str",
+    "macros",
+    "salsa_unstable",
+    "inventory",
+] }
 schemars = { version = "0.8.16" }
 seahash = { version = "4.1.0" }
 serde = { version = "1.0.197", features = ["derive"] }
@@ -150,7 +160,7 @@ serde_with = { version = "3.6.0", default-features = false, features = [
 ] }
 shellexpand = { version = "3.0.0" }
 similar = { version = "2.4.0", features = ["inline"] }
-smallvec = { version = "1.13.2" }
+smallvec = { version = "1.13.2", features = ["union", "const_generics", "const_new"] }
 snapbox = { version = "0.6.0", features = [
     "diff",
     "term-svg",

README.md

@@ -148,8 +148,8 @@ curl -LsSf https://astral.sh/ruff/install.sh | sh
 powershell -c "irm https://astral.sh/ruff/install.ps1 | iex"
 
 # For a specific version.
-curl -LsSf https://astral.sh/ruff/0.12.3/install.sh | sh
-powershell -c "irm https://astral.sh/ruff/0.12.3/install.ps1 | iex"
+curl -LsSf https://astral.sh/ruff/0.12.8/install.sh | sh
+powershell -c "irm https://astral.sh/ruff/0.12.8/install.ps1 | iex"
 ```
 
 You can also install Ruff via [Homebrew](https://formulae.brew.sh/formula/ruff), [Conda](https://anaconda.org/conda-forge/ruff),
@@ -182,7 +182,7 @@ Ruff can also be used as a [pre-commit](https://pre-commit.com/) hook via [`ruff
 ```yaml
 - repo: https://github.com/astral-sh/ruff-pre-commit
   # Ruff version.
-  rev: v0.12.3
+  rev: v0.12.8
   hooks:
     # Run the linter.
     - id: ruff-check

crates/ruff/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "ruff"
-version = "0.12.3"
+version = "0.12.8"
 publish = true
 authors = { workspace = true }
 edition = { workspace = true }

crates/ruff/src/args.rs

@@ -169,6 +169,9 @@ pub struct AnalyzeGraphCommand {
     /// Attempt to detect imports from string literals.
     #[clap(long)]
     detect_string_imports: bool,
+    /// The minimum number of dots in a string import to consider it a valid import.
+    #[clap(long)]
+    min_dots: Option<usize>,
     /// Enable preview mode. Use `--no-preview` to disable.
     #[arg(long, overrides_with("no_preview"))]
     preview: bool,
@@ -808,6 +811,7 @@ impl AnalyzeGraphCommand {
             } else {
                 None
             },
+            string_imports_min_dots: self.min_dots,
             preview: resolve_bool_arg(self.preview, self.no_preview).map(PreviewMode::from),
             target_version: self.target_version.map(ast::PythonVersion::from),
             ..ExplicitConfigOverrides::default()
@@ -1305,6 +1309,7 @@ struct ExplicitConfigOverrides {
     show_fixes: Option<bool>,
     extension: Option<Vec<ExtensionPair>>,
     detect_string_imports: Option<bool>,
+    string_imports_min_dots: Option<usize>,
 }
 
 impl ConfigurationTransformer for ExplicitConfigOverrides {
@@ -1392,6 +1397,9 @@ impl ConfigurationTransformer for ExplicitConfigOverrides {
         if let Some(detect_string_imports) = &self.detect_string_imports {
             config.analyze.detect_string_imports = Some(*detect_string_imports);
         }
+        if let Some(string_imports_min_dots) = &self.string_imports_min_dots {
+            config.analyze.string_imports_min_dots = Some(*string_imports_min_dots);
+        }
 
         config
     }

crates/ruff/src/cache.rs

@@ -454,7 +454,7 @@ impl LintCacheData {
                 CacheMessage {
                     rule,
                     body: msg.body().to_string(),
-                    suggestion: msg.suggestion().map(ToString::to_string),
+                    suggestion: msg.first_help_text().map(ToString::to_string),
                     range: msg.expect_range(),
                     parent: msg.parent(),
                     fix: msg.fix().cloned(),

crates/ruff/src/commands/analyze_graph.rs

@@ -102,7 +102,7 @@ pub(crate) fn analyze_graph(
 
                 // Resolve the per-file settings.
                 let settings = resolver.resolve(path);
-                let string_imports = settings.analyze.detect_string_imports;
+                let string_imports = settings.analyze.string_imports;
                 let include_dependencies = settings.analyze.include_dependencies.get(path).cloned();
 
                 // Skip excluded files.

crates/ruff/src/commands/check.rs

@@ -279,6 +279,7 @@ mod test {
 
         TextEmitter::default()
             .with_show_fix_status(true)
+            .with_color(false)
             .emit(
                 &mut output,
                 &diagnostics.inner,

crates/ruff/src/printer.rs

@@ -15,8 +15,8 @@ use ruff_db::diagnostic::{
 use ruff_linter::fs::relativize_path;
 use ruff_linter::logging::LogLevel;
 use ruff_linter::message::{
-    Emitter, EmitterContext, GithubEmitter, GitlabEmitter, GroupedEmitter, JunitEmitter,
-    SarifEmitter, TextEmitter,
+    Emitter, EmitterContext, GithubEmitter, GitlabEmitter, GroupedEmitter, SarifEmitter,
+    TextEmitter,
 };
 use ruff_linter::notify_user;
 use ruff_linter::settings::flags::{self};
@@ -252,7 +252,11 @@ impl Printer {
                 write!(writer, "{value}")?;
             }
             OutputFormat::Junit => {
-                JunitEmitter.emit(writer, &diagnostics.inner, &context)?;
+                let config = DisplayDiagnosticConfig::default()
+                    .format(DiagnosticFormat::Junit)
+                    .preview(preview);
+                let value = DisplayDiagnostics::new(&context, &config, &diagnostics.inner);
+                write!(writer, "{value}")?;
             }
             OutputFormat::Concise | OutputFormat::Full => {
                 TextEmitter::default()
@@ -260,6 +264,7 @@ impl Printer {
                     .with_show_fix_diff(self.flags.intersects(Flags::SHOW_FIX_DIFF))
                     .with_show_source(self.format == OutputFormat::Full)
                     .with_unsafe_fixes(self.unsafe_fixes)
+                    .with_preview(preview)
                     .emit(writer, &diagnostics.inner, &context)?;
 
                 if self.flags.intersects(Flags::SHOW_FIX_SUMMARY) {

crates/ruff/tests/analyze_graph.rs

@@ -57,33 +57,40 @@ fn dependencies() -> Result<()> {
         .write_str(indoc::indoc! {r#"
         def f(): pass
     "#})?;
+    root.child("ruff")
+        .child("e.pyi")
+        .write_str(indoc::indoc! {r#"
+        def f() -> None: ...
+    "#})?;
 
     insta::with_settings!({
         filters => INSTA_FILTERS.to_vec(),
     }, {
-        assert_cmd_snapshot!(command().current_dir(&root), @r###"
-            success: true
-            exit_code: 0
-            ----- stdout -----
-            {
-              "ruff/__init__.py": [],
-              "ruff/a.py": [
-                "ruff/b.py"
-              ],
-              "ruff/b.py": [
-                "ruff/c.py"
-              ],
-              "ruff/c.py": [
-                "ruff/d.py"
-              ],
-              "ruff/d.py": [
-                "ruff/e.py"
-              ],
-              "ruff/e.py": []
-            }
+        assert_cmd_snapshot!(command().current_dir(&root), @r#"
+        success: true
+        exit_code: 0
+        ----- stdout -----
+        {
+          "ruff/__init__.py": [],
+          "ruff/a.py": [
+            "ruff/b.py"
+          ],
+          "ruff/b.py": [
+            "ruff/c.py"
+          ],
+          "ruff/c.py": [
+            "ruff/d.py"
+          ],
+          "ruff/d.py": [
+            "ruff/e.py",
+            "ruff/e.pyi"
+          ],
+          "ruff/e.py": [],
+          "ruff/e.pyi": []
+        }
 
-            ----- stderr -----
-            "###);
+        ----- stderr -----
+        "#);
     });
 
     Ok(())
@@ -197,23 +204,43 @@ fn string_detection() -> Result<()> {
     insta::with_settings!({
         filters => INSTA_FILTERS.to_vec(),
     }, {
-        assert_cmd_snapshot!(command().arg("--detect-string-imports").current_dir(&root), @r###"
-            success: true
-            exit_code: 0
-            ----- stdout -----
-            {
-              "ruff/__init__.py": [],
-              "ruff/a.py": [
-                "ruff/b.py"
-              ],
-              "ruff/b.py": [
-                "ruff/c.py"
-              ],
-              "ruff/c.py": []
-            }
+        assert_cmd_snapshot!(command().arg("--detect-string-imports").current_dir(&root), @r#"
+        success: true
+        exit_code: 0
+        ----- stdout -----
+        {
+          "ruff/__init__.py": [],
+          "ruff/a.py": [
+            "ruff/b.py"
+          ],
+          "ruff/b.py": [],
+          "ruff/c.py": []
+        }
 
-            ----- stderr -----
-            "###);
+        ----- stderr -----
+        "#);
+    });
+
+    insta::with_settings!({
+        filters => INSTA_FILTERS.to_vec(),
+    }, {
+        assert_cmd_snapshot!(command().arg("--detect-string-imports").arg("--min-dots").arg("1").current_dir(&root), @r#"
+        success: true
+        exit_code: 0
+        ----- stdout -----
+        {
+          "ruff/__init__.py": [],
+          "ruff/a.py": [
+            "ruff/b.py"
+          ],
+          "ruff/b.py": [
+            "ruff/c.py"
+          ],
+          "ruff/c.py": []
+        }
+
+        ----- stderr -----
+        "#);
     });
 
     Ok(())

crates/ruff/tests/integration_test.rs

@@ -798,7 +798,7 @@ fn stdin_parse_error() {
     success: false
     exit_code: 1
     ----- stdout -----
-    -:1:16: SyntaxError: Expected one or more symbol names after import
+    -:1:16: invalid-syntax: Expected one or more symbol names after import
       |
     1 | from foo import
       |                ^
@@ -818,14 +818,14 @@ fn stdin_multiple_parse_error() {
     success: false
     exit_code: 1
     ----- stdout -----
-    -:1:16: SyntaxError: Expected one or more symbol names after import
+    -:1:16: invalid-syntax: Expected one or more symbol names after import
       |
     1 | from foo import
       |                ^
     2 | bar =
       |
 
-    -:2:6: SyntaxError: Expected an expression
+    -:2:6: invalid-syntax: Expected an expression
       |
     1 | from foo import
     2 | bar =
@@ -847,7 +847,7 @@ fn parse_error_not_included() {
     success: false
     exit_code: 1
     ----- stdout -----
-    -:1:6: SyntaxError: Expected an expression
+    -:1:6: invalid-syntax: Expected an expression
       |
     1 | foo =
       |      ^

crates/ruff/tests/lint.rs

@@ -2422,7 +2422,7 @@ requires-python = ">= 3.11"
         analyze.exclude = []
         analyze.preview = disabled
         analyze.target_version = 3.11
-        analyze.detect_string_imports = false
+        analyze.string_imports = disabled
         analyze.extension = ExtensionMapping({})
         analyze.include_dependencies = {}
 
@@ -2734,7 +2734,7 @@ requires-python = ">= 3.11"
         analyze.exclude = []
         analyze.preview = disabled
         analyze.target_version = 3.10
-        analyze.detect_string_imports = false
+        analyze.string_imports = disabled
         analyze.extension = ExtensionMapping({})
         analyze.include_dependencies = {}
 
@@ -3098,7 +3098,7 @@ from typing import Union;foo: Union[int, str] = 1
         analyze.exclude = []
         analyze.preview = disabled
         analyze.target_version = 3.11
-        analyze.detect_string_imports = false
+        analyze.string_imports = disabled
         analyze.extension = ExtensionMapping({})
         analyze.include_dependencies = {}
 
@@ -3478,7 +3478,7 @@ from typing import Union;foo: Union[int, str] = 1
         analyze.exclude = []
         analyze.preview = disabled
         analyze.target_version = 3.11
-        analyze.detect_string_imports = false
+        analyze.string_imports = disabled
         analyze.extension = ExtensionMapping({})
         analyze.include_dependencies = {}
 
@@ -3806,7 +3806,7 @@ from typing import Union;foo: Union[int, str] = 1
         analyze.exclude = []
         analyze.preview = disabled
         analyze.target_version = 3.10
-        analyze.detect_string_imports = false
+        analyze.string_imports = disabled
         analyze.extension = ExtensionMapping({})
         analyze.include_dependencies = {}
 
@@ -4134,7 +4134,7 @@ from typing import Union;foo: Union[int, str] = 1
         analyze.exclude = []
         analyze.preview = disabled
         analyze.target_version = 3.9
-        analyze.detect_string_imports = false
+        analyze.string_imports = disabled
         analyze.extension = ExtensionMapping({})
         analyze.include_dependencies = {}
 
@@ -4419,7 +4419,7 @@ from typing import Union;foo: Union[int, str] = 1
         analyze.exclude = []
         analyze.preview = disabled
         analyze.target_version = 3.9
-        analyze.detect_string_imports = false
+        analyze.string_imports = disabled
         analyze.extension = ExtensionMapping({})
         analyze.include_dependencies = {}
 
@@ -4757,7 +4757,7 @@ from typing import Union;foo: Union[int, str] = 1
         analyze.exclude = []
         analyze.preview = disabled
         analyze.target_version = 3.10
-        analyze.detect_string_imports = false
+        analyze.string_imports = disabled
         analyze.extension = ExtensionMapping({})
         analyze.include_dependencies = {}
 
@@ -4996,6 +4996,37 @@ fn flake8_import_convention_invalid_aliases_config_module_name() -> Result<()> {
     Ok(())
 }
 
+#[test]
+fn flake8_import_convention_nfkc_normalization() -> Result<()> {
+    let tempdir = TempDir::new()?;
+    let ruff_toml = tempdir.path().join("ruff.toml");
+    fs::write(
+        &ruff_toml,
+        r#"
+[lint.flake8-import-conventions.aliases]
+"test.module" = "_﹏𝘥𝘦𝘣𝘶𝘨﹏﹏"
+"#,
+    )?;
+
+    insta::with_settings!({
+        filters => vec![(tempdir_filter(&tempdir).as_str(), "[TMP]/")]
+    }, {
+        assert_cmd_snapshot!(Command::new(get_cargo_bin(BIN_NAME))
+            .args(STDIN_BASE_OPTIONS)
+            .arg("--config")
+            .arg(&ruff_toml)
+    , @r"
+        success: false
+        exit_code: 2
+        ----- stdout -----
+
+        ----- stderr -----
+        ruff failed
+          Cause: Invalid alias for module 'test.module': alias normalizes to '__debug__', which is not allowed.
+        ");});
+    Ok(())
+}
+
 #[test]
 fn flake8_import_convention_unused_aliased_import() {
     assert_cmd_snapshot!(
@@ -5389,7 +5420,7 @@ fn walrus_before_py38() {
     success: false
     exit_code: 1
     ----- stdout -----
-    test.py:1:2: SyntaxError: Cannot use named assignment expression (`:=`) on Python 3.7 (syntax was added in Python 3.8)
+    test.py:1:2: invalid-syntax: Cannot use named assignment expression (`:=`) on Python 3.7 (syntax was added in Python 3.8)
     Found 1 error.
 
     ----- stderr -----
@@ -5435,15 +5466,15 @@ match 2:
         print("it's one")
 "#
         ),
-        @r###"
+        @r"
     success: false
     exit_code: 1
     ----- stdout -----
-    test.py:2:1: SyntaxError: Cannot use `match` statement on Python 3.9 (syntax was added in Python 3.10)
+    test.py:2:1: invalid-syntax: Cannot use `match` statement on Python 3.9 (syntax was added in Python 3.10)
     Found 1 error.
 
     ----- stderr -----
-    "###
+    "
     );
 
     // syntax error on 3.9 with preview
@@ -5464,7 +5495,7 @@ match 2:
     success: false
     exit_code: 1
     ----- stdout -----
-    test.py:2:1: SyntaxError: Cannot use `match` statement on Python 3.9 (syntax was added in Python 3.10)
+    test.py:2:1: invalid-syntax: Cannot use `match` statement on Python 3.9 (syntax was added in Python 3.10)
     Found 1 error.
 
     ----- stderr -----
@@ -5492,7 +5523,7 @@ fn cache_syntax_errors() -> Result<()> {
     success: false
     exit_code: 1
     ----- stdout -----
-    main.py:1:1: SyntaxError: Cannot use `match` statement on Python 3.9 (syntax was added in Python 3.10)
+    main.py:1:1: invalid-syntax: Cannot use `match` statement on Python 3.9 (syntax was added in Python 3.10)
 
     ----- stderr -----
     "
@@ -5505,7 +5536,7 @@ fn cache_syntax_errors() -> Result<()> {
     success: false
     exit_code: 1
     ----- stdout -----
-    main.py:1:1: SyntaxError: Cannot use `match` statement on Python 3.9 (syntax was added in Python 3.10)
+    main.py:1:1: invalid-syntax: Cannot use `match` statement on Python 3.9 (syntax was added in Python 3.10)
 
     ----- stderr -----
     "
@@ -5618,7 +5649,7 @@ fn semantic_syntax_errors() -> Result<()> {
     success: false
     exit_code: 1
     ----- stdout -----
-    main.py:1:3: SyntaxError: assignment expression cannot rebind comprehension variable
+    main.py:1:3: invalid-syntax: assignment expression cannot rebind comprehension variable
     main.py:1:20: F821 Undefined name `foo`
 
     ----- stderr -----
@@ -5632,7 +5663,7 @@ fn semantic_syntax_errors() -> Result<()> {
     success: false
     exit_code: 1
     ----- stdout -----
-    main.py:1:3: SyntaxError: assignment expression cannot rebind comprehension variable
+    main.py:1:3: invalid-syntax: assignment expression cannot rebind comprehension variable
     main.py:1:20: F821 Undefined name `foo`
 
     ----- stderr -----
@@ -5651,7 +5682,7 @@ fn semantic_syntax_errors() -> Result<()> {
     success: false
     exit_code: 1
     ----- stdout -----
-    -:1:3: SyntaxError: assignment expression cannot rebind comprehension variable
+    -:1:3: invalid-syntax: assignment expression cannot rebind comprehension variable
     Found 1 error.
 
     ----- stderr -----
@@ -5718,8 +5749,11 @@ match 42:  # invalid-syntax
 
     let snapshot = format!("output_format_{output_format}");
 
+    let project_dir = dunce::canonicalize(tempdir.path())?;
+
     insta::with_settings!({
         filters => vec![
+            (tempdir_filter(&project_dir).as_str(), "[TMP]/"),
             (tempdir_filter(&tempdir).as_str(), "[TMP]/"),
             (r#""[^"]+\\?/?input.py"#, r#""[TMP]/input.py"#),
             (ruff_linter::VERSION, "[VERSION]"),

crates/ruff/tests/snapshots/integration_test__rule_f401.snap

@@ -95,6 +95,6 @@ is stricter, which could affect the suggested fix. See [this FAQ section](https:
 ## References
 - [Python documentation: `import`](https://docs.python.org/3/reference/simple_stmts.html#the-import-statement)
 - [Python documentation: `importlib.util.find_spec`](https://docs.python.org/3/library/importlib.html#importlib.util.find_spec)
-- [Typing documentation: interface conventions](https://typing.python.org/en/latest/source/libraries.html#library-interface-public-and-private-symbols)
+- [Typing documentation: interface conventions](https://typing.python.org/en/latest/spec/distributing.html#library-interface-public-and-private-symbols)
 
 ----- stderr -----

crates/ruff/tests/snapshots/lint__output_format_azure.snap

@@ -18,6 +18,6 @@ exit_code: 1
 ----- stdout -----
 ##vso[task.logissue type=error;sourcepath=[TMP]/input.py;linenumber=1;columnnumber=8;code=F401;]`os` imported but unused
 ##vso[task.logissue type=error;sourcepath=[TMP]/input.py;linenumber=2;columnnumber=5;code=F821;]Undefined name `y`
-##vso[task.logissue type=error;sourcepath=[TMP]/input.py;linenumber=3;columnnumber=1;]SyntaxError: Cannot use `match` statement on Python 3.9 (syntax was added in Python 3.10)
+##vso[task.logissue type=error;sourcepath=[TMP]/input.py;linenumber=3;columnnumber=1;code=invalid-syntax;]Cannot use `match` statement on Python 3.9 (syntax was added in Python 3.10)
 
 ----- stderr -----

crates/ruff/tests/snapshots/lint__output_format_concise.snap

@@ -18,7 +18,7 @@ exit_code: 1
 ----- stdout -----
 input.py:1:8: F401 [*] `os` imported but unused
 input.py:2:5: F821 Undefined name `y`
-input.py:3:1: SyntaxError: Cannot use `match` statement on Python 3.9 (syntax was added in Python 3.10)
+input.py:3:1: invalid-syntax: Cannot use `match` statement on Python 3.9 (syntax was added in Python 3.10)
 Found 3 errors.
 [*] 1 fixable with the `--fix` option.
 

crates/ruff/tests/snapshots/lint__output_format_full.snap

@@ -34,7 +34,7 @@ input.py:2:5: F821 Undefined name `y`
 4 |     case _: ...
   |
 
-input.py:3:1: SyntaxError: Cannot use `match` statement on Python 3.9 (syntax was added in Python 3.10)
+input.py:3:1: invalid-syntax: Cannot use `match` statement on Python 3.9 (syntax was added in Python 3.10)
   |
 1 | import os  # F401
 2 | x = y      # F821

crates/ruff/tests/snapshots/lint__output_format_github.snap

@@ -18,6 +18,6 @@ exit_code: 1
 ----- stdout -----
 ::error title=Ruff (F401),file=[TMP]/input.py,line=1,col=8,endLine=1,endColumn=10::input.py:1:8: F401 `os` imported but unused
 ::error title=Ruff (F821),file=[TMP]/input.py,line=2,col=5,endLine=2,endColumn=6::input.py:2:5: F821 Undefined name `y`
-::error title=Ruff,file=[TMP]/input.py,line=3,col=1,endLine=3,endColumn=6::input.py:3:1: SyntaxError: Cannot use `match` statement on Python 3.9 (syntax was added in Python 3.10)
+::error title=Ruff (invalid-syntax),file=[TMP]/input.py,line=3,col=1,endLine=3,endColumn=6::input.py:3:1: invalid-syntax: Cannot use `match` statement on Python 3.9 (syntax was added in Python 3.10)
 
 ----- stderr -----

crates/ruff/tests/snapshots/lint__output_format_gitlab.snap

@@ -22,11 +22,17 @@ exit_code: 1
     "description": "`os` imported but unused",
     "fingerprint": "4dbad37161e65c72",
     "location": {
-      "lines": {
-        "begin": 1,
-        "end": 1
-      },
-      "path": "input.py"
+      "path": "input.py",
+      "positions": {
+        "begin": {
+          "column": 8,
+          "line": 1
+        },
+        "end": {
+          "column": 10,
+          "line": 1
+        }
+      }
     },
     "severity": "major"
   },
@@ -35,11 +41,17 @@ exit_code: 1
     "description": "Undefined name `y`",
     "fingerprint": "7af59862a085230",
     "location": {
-      "lines": {
-        "begin": 2,
-        "end": 2
-      },
-      "path": "input.py"
+      "path": "input.py",
+      "positions": {
+        "begin": {
+          "column": 5,
+          "line": 2
+        },
+        "end": {
+          "column": 6,
+          "line": 2
+        }
+      }
     },
     "severity": "major"
   },
@@ -48,11 +60,17 @@ exit_code: 1
     "description": "Cannot use `match` statement on Python 3.9 (syntax was added in Python 3.10)",
     "fingerprint": "e558cec859bb66e8",
     "location": {
-      "lines": {
-        "begin": 3,
-        "end": 3
-      },
-      "path": "input.py"
+      "path": "input.py",
+      "positions": {
+        "begin": {
+          "column": 1,
+          "line": 3
+        },
+        "end": {
+          "column": 6,
+          "line": 3
+        }
+      }
     },
     "severity": "major"
   }

crates/ruff/tests/snapshots/lint__output_format_grouped.snap

@@ -19,7 +19,7 @@ exit_code: 1
 input.py:
   1:8 F401 [*] `os` imported but unused
   2:5 F821 Undefined name `y`
-  3:1 SyntaxError: Cannot use `match` statement on Python 3.9 (syntax was added in Python 3.10)
+  3:1 invalid-syntax: Cannot use `match` statement on Python 3.9 (syntax was added in Python 3.10)
 
 Found 3 errors.
 [*] 1 fixable with the `--fix` option.

crates/ruff/tests/snapshots/lint__output_format_json-lines.snap

@@ -18,6 +18,6 @@ exit_code: 1
 ----- stdout -----
 {"cell":null,"code":"F401","end_location":{"column":10,"row":1},"filename":"[TMP]/input.py","fix":{"applicability":"safe","edits":[{"content":"","end_location":{"column":1,"row":2},"location":{"column":1,"row":1}}],"message":"Remove unused import: `os`"},"location":{"column":8,"row":1},"message":"`os` imported but unused","noqa_row":1,"url":"https://docs.astral.sh/ruff/rules/unused-import"}
 {"cell":null,"code":"F821","end_location":{"column":6,"row":2},"filename":"[TMP]/input.py","fix":null,"location":{"column":5,"row":2},"message":"Undefined name `y`","noqa_row":2,"url":"https://docs.astral.sh/ruff/rules/undefined-name"}
-{"cell":null,"code":null,"end_location":{"column":6,"row":3},"filename":"[TMP]/input.py","fix":null,"location":{"column":1,"row":3},"message":"SyntaxError: Cannot use `match` statement on Python 3.9 (syntax was added in Python 3.10)","noqa_row":null,"url":null}
+{"cell":null,"code":"invalid-syntax","end_location":{"column":6,"row":3},"filename":"[TMP]/input.py","fix":null,"location":{"column":1,"row":3},"message":"Cannot use `match` statement on Python 3.9 (syntax was added in Python 3.10)","noqa_row":null,"url":null}
 
 ----- stderr -----

crates/ruff/tests/snapshots/lint__output_format_json.snap

@@ -69,7 +69,7 @@ exit_code: 1
   },
   {
     "cell": null,
-    "code": null,
+    "code": "invalid-syntax",
     "end_location": {
       "column": 6,
       "row": 3
@@ -80,7 +80,7 @@ exit_code: 1
       "column": 1,
       "row": 3
     },
-    "message": "SyntaxError: Cannot use `match` statement on Python 3.9 (syntax was added in Python 3.10)",
+    "message": "Cannot use `match` statement on Python 3.9 (syntax was added in Python 3.10)",
     "noqa_row": null,
     "url": null
   }

crates/ruff/tests/snapshots/lint__output_format_junit.snap

@@ -25,8 +25,8 @@ exit_code: 1
         <testcase name="org.ruff.F821" classname="[TMP]/input" line="2" column="5">
             <failure message="Undefined name `y`">line 2, col 5, Undefined name `y`</failure>
         </testcase>
-        <testcase name="org.ruff" classname="[TMP]/input" line="3" column="1">
-            <failure message="SyntaxError: Cannot use `match` statement on Python 3.9 (syntax was added in Python 3.10)">line 3, col 1, SyntaxError: Cannot use `match` statement on Python 3.9 (syntax was added in Python 3.10)</failure>
+        <testcase name="org.ruff.invalid-syntax" classname="[TMP]/input" line="3" column="1">
+            <failure message="Cannot use `match` statement on Python 3.9 (syntax was added in Python 3.10)">line 3, col 1, Cannot use `match` statement on Python 3.9 (syntax was added in Python 3.10)</failure>
         </testcase>
     </testsuite>
 </testsuites>

crates/ruff/tests/snapshots/lint__output_format_pylint.snap

@@ -18,6 +18,6 @@ exit_code: 1
 ----- stdout -----
 input.py:1: [F401] `os` imported but unused
 input.py:2: [F821] Undefined name `y`
-input.py:3: [invalid-syntax] SyntaxError: Cannot use `match` statement on Python 3.9 (syntax was added in Python 3.10)
+input.py:3: [invalid-syntax] Cannot use `match` statement on Python 3.9 (syntax was added in Python 3.10)
 
 ----- stderr -----

crates/ruff/tests/snapshots/lint__output_format_rdjson.snap

@@ -90,7 +90,7 @@ exit_code: 1
           }
         }
       },
-      "message": "SyntaxError: Cannot use `match` statement on Python 3.9 (syntax was added in Python 3.10)"
+      "message": "Cannot use `match` statement on Python 3.9 (syntax was added in Python 3.10)"
     }
   ],
   "severity": "WARNING",

crates/ruff/tests/snapshots/lint__output_format_sarif.snap

@@ -83,9 +83,9 @@ exit_code: 1
             }
           ],
           "message": {
-            "text": "SyntaxError: Cannot use `match` statement on Python 3.9 (syntax was added in Python 3.10)"
+            "text": "Cannot use `match` statement on Python 3.9 (syntax was added in Python 3.10)"
           },
-          "ruleId": null
+          "ruleId": "invalid-syntax"
         }
       ],
       "tool": {
@@ -95,7 +95,7 @@ exit_code: 1
           "rules": [
             {
               "fullDescription": {
-                "text": "## What it does\nChecks for unused imports.\n\n## Why is this bad?\nUnused imports add a performance overhead at runtime, and risk creating\nimport cycles. They also increase the cognitive load of reading the code.\n\nIf an import statement is used to check for the availability or existence\nof a module, consider using `importlib.util.find_spec` instead.\n\nIf an import statement is used to re-export a symbol as part of a module's\npublic interface, consider using a \"redundant\" import alias, which\ninstructs Ruff (and other tools) to respect the re-export, and avoid\nmarking it as unused, as in:\n\n```python\nfrom module import member as member\n```\n\nAlternatively, you can use `__all__` to declare a symbol as part of the module's\ninterface, as in:\n\n```python\n# __init__.py\nimport some_module\n\n__all__ = [\"some_module\"]\n```\n\n## Fix safety\n\nFixes to remove unused imports are safe, except in `__init__.py` files.\n\nApplying fixes to `__init__.py` files is currently in preview. The fix offered depends on the\ntype of the unused import. Ruff will suggest a safe fix to export first-party imports with\neither a redundant alias or, if already present in the file, an `__all__` entry. If multiple\n`__all__` declarations are present, Ruff will not offer a fix. Ruff will suggest an unsafe fix\nto remove third-party and standard library imports -- the fix is unsafe because the module's\ninterface changes.\n\n## Example\n\n```python\nimport numpy as np  # unused import\n\n\ndef area(radius):\n    return 3.14 * radius**2\n```\n\nUse instead:\n\n```python\ndef area(radius):\n    return 3.14 * radius**2\n```\n\nTo check the availability of a module, use `importlib.util.find_spec`:\n\n```python\nfrom importlib.util import find_spec\n\nif find_spec(\"numpy\") is not None:\n    print(\"numpy is installed\")\nelse:\n    print(\"numpy is not installed\")\n```\n\n## Preview\nWhen [preview](https://docs.astral.sh/ruff/preview/) is enabled,\nthe criterion for determining whether an import is first-party\nis stricter, which could affect the suggested fix. See [this FAQ section](https://docs.astral.sh/ruff/faq/#how-does-ruff-determine-which-of-my-imports-are-first-party-third-party-etc) for more details.\n\n## Options\n- `lint.ignore-init-module-imports`\n- `lint.pyflakes.allowed-unused-imports`\n\n## References\n- [Python documentation: `import`](https://docs.python.org/3/reference/simple_stmts.html#the-import-statement)\n- [Python documentation: `importlib.util.find_spec`](https://docs.python.org/3/library/importlib.html#importlib.util.find_spec)\n- [Typing documentation: interface conventions](https://typing.python.org/en/latest/source/libraries.html#library-interface-public-and-private-symbols)\n"
+                "text": "## What it does\nChecks for unused imports.\n\n## Why is this bad?\nUnused imports add a performance overhead at runtime, and risk creating\nimport cycles. They also increase the cognitive load of reading the code.\n\nIf an import statement is used to check for the availability or existence\nof a module, consider using `importlib.util.find_spec` instead.\n\nIf an import statement is used to re-export a symbol as part of a module's\npublic interface, consider using a \"redundant\" import alias, which\ninstructs Ruff (and other tools) to respect the re-export, and avoid\nmarking it as unused, as in:\n\n```python\nfrom module import member as member\n```\n\nAlternatively, you can use `__all__` to declare a symbol as part of the module's\ninterface, as in:\n\n```python\n# __init__.py\nimport some_module\n\n__all__ = [\"some_module\"]\n```\n\n## Fix safety\n\nFixes to remove unused imports are safe, except in `__init__.py` files.\n\nApplying fixes to `__init__.py` files is currently in preview. The fix offered depends on the\ntype of the unused import. Ruff will suggest a safe fix to export first-party imports with\neither a redundant alias or, if already present in the file, an `__all__` entry. If multiple\n`__all__` declarations are present, Ruff will not offer a fix. Ruff will suggest an unsafe fix\nto remove third-party and standard library imports -- the fix is unsafe because the module's\ninterface changes.\n\n## Example\n\n```python\nimport numpy as np  # unused import\n\n\ndef area(radius):\n    return 3.14 * radius**2\n```\n\nUse instead:\n\n```python\ndef area(radius):\n    return 3.14 * radius**2\n```\n\nTo check the availability of a module, use `importlib.util.find_spec`:\n\n```python\nfrom importlib.util import find_spec\n\nif find_spec(\"numpy\") is not None:\n    print(\"numpy is installed\")\nelse:\n    print(\"numpy is not installed\")\n```\n\n## Preview\nWhen [preview](https://docs.astral.sh/ruff/preview/) is enabled,\nthe criterion for determining whether an import is first-party\nis stricter, which could affect the suggested fix. See [this FAQ section](https://docs.astral.sh/ruff/faq/#how-does-ruff-determine-which-of-my-imports-are-first-party-third-party-etc) for more details.\n\n## Options\n- `lint.ignore-init-module-imports`\n- `lint.pyflakes.allowed-unused-imports`\n\n## References\n- [Python documentation: `import`](https://docs.python.org/3/reference/simple_stmts.html#the-import-statement)\n- [Python documentation: `importlib.util.find_spec`](https://docs.python.org/3/library/importlib.html#importlib.util.find_spec)\n- [Typing documentation: interface conventions](https://typing.python.org/en/latest/spec/distributing.html#library-interface-public-and-private-symbols)\n"
               },
               "help": {
                 "text": "`{name}` imported but unused; consider using `importlib.util.find_spec` to test for availability"

crates/ruff/tests/snapshots/show_settings__display_default_settings.snap

@@ -392,7 +392,7 @@ formatter.docstring_code_line_width = dynamic
 analyze.exclude = []
 analyze.preview = disabled
 analyze.target_version = 3.7
-analyze.detect_string_imports = false
+analyze.string_imports = disabled
 analyze.extension = ExtensionMapping({})
 analyze.include_dependencies = {}
 

crates/ruff_annotate_snippets/src/lib.rs

@@ -1,3 +1,5 @@
+#![expect(clippy::needless_doctest_main)]
+
 //! A library for formatting of text or programming code snippets.
 //!
 //! It's primary purpose is to build an ASCII-graphical representation of the snippet

crates/ruff_annotate_snippets/src/renderer/display_list.rs

@@ -193,9 +193,14 @@ impl DisplaySet<'_> {
         stylesheet: &Stylesheet,
         buffer: &mut StyledBuffer,
     ) -> fmt::Result {
+        let hide_severity = annotation.annotation_type.is_none();
         let color = get_annotation_style(&annotation.annotation_type, stylesheet);
         let formatted_len = if let Some(id) = &annotation.id {
-            2 + id.len() + annotation_type_len(&annotation.annotation_type)
+            if hide_severity {
+                id.len()
+            } else {
+                2 + id.len() + annotation_type_len(&annotation.annotation_type)
+            }
         } else {
             annotation_type_len(&annotation.annotation_type)
         };
@@ -209,18 +214,66 @@ impl DisplaySet<'_> {
         if formatted_len == 0 {
             self.format_label(line_offset, &annotation.label, stylesheet, buffer)
         } else {
-            let id = match &annotation.id {
-                Some(id) => format!("[{id}]"),
-                None => String::new(),
-            };
-            buffer.append(
-                line_offset,
-                &format!("{}{}", annotation_type_str(&annotation.annotation_type), id),
-                *color,
-            );
+            // TODO(brent) All of this complicated checking of `hide_severity` should be reverted
+            // once we have real severities in Ruff. This code is trying to account for two
+            // different cases:
+            //
+            // - main diagnostic message
+            // - subdiagnostic message
+            //
+            // In the first case, signaled by `hide_severity = true`, we want to print the ID (the
+            // noqa code for a ruff lint diagnostic, e.g. `F401`, or `invalid-syntax` for a syntax
+            // error) without brackets. Instead, for subdiagnostics, we actually want to print the
+            // severity (usually `help`) regardless of the `hide_severity` setting. This is signaled
+            // by an ID of `None`.
+            //
+            // With real severities these should be reported more like in ty:
+            //
+            // ```
+            // error[F401]: `math` imported but unused
+            // error[invalid-syntax]: Cannot use `match` statement on Python 3.9...
+            // ```
+            //
+            // instead of the current versions intended to mimic the old Ruff output format:
+            //
+            // ```
+            // F401 `math` imported but unused
+            // invalid-syntax: Cannot use `match` statement on Python 3.9...
+            // ```
+            //
+            // Note that the `invalid-syntax` colon is added manually in `ruff_db`, not here. We
+            // could eventually add a colon to Ruff lint diagnostics (`F401:`) and then make the
+            // colon below unconditional again.
+            //
+            // This also applies to the hard-coded `stylesheet.error()` styling of the
+            // hidden-severity `id`. This should just be `*color` again later, but for now we don't
+            // want an unformatted `id`, which is what `get_annotation_style` returns for
+            // `DisplayAnnotationType::None`.
+            let annotation_type = annotation_type_str(&annotation.annotation_type);
+            if let Some(id) = annotation.id {
+                if hide_severity {
+                    buffer.append(line_offset, &format!("{id} "), *stylesheet.error());
+                } else {
+                    buffer.append(line_offset, &format!("{annotation_type}[{id}]"), *color);
+                }
+            } else {
+                buffer.append(line_offset, annotation_type, *color);
+            }
+
+            if annotation.is_fixable {
+                buffer.append(line_offset, "[", stylesheet.none);
+                buffer.append(line_offset, "*", stylesheet.help);
+                buffer.append(line_offset, "]", stylesheet.none);
+                // In the hide-severity case, we need a space instead of the colon and space below.
+                if hide_severity {
+                    buffer.append(line_offset, " ", stylesheet.none);
+                }
+            }
 
             if !is_annotation_empty(annotation) {
-                buffer.append(line_offset, ": ", stylesheet.none);
+                if annotation.id.is_none() || !hide_severity {
+                    buffer.append(line_offset, ": ", stylesheet.none);
+                }
                 self.format_label(line_offset, &annotation.label, stylesheet, buffer)?;
             }
             Ok(())
@@ -249,11 +302,15 @@ impl DisplaySet<'_> {
                 let lineno_color = stylesheet.line_no();
                 buffer.puts(line_offset, lineno_width, header_sigil, *lineno_color);
                 buffer.puts(line_offset, lineno_width + 4, path, stylesheet.none);
-                if let Some((col, row)) = pos {
-                    buffer.append(line_offset, ":", stylesheet.none);
-                    buffer.append(line_offset, col.to_string().as_str(), stylesheet.none);
+                if let Some(Position { row, col, cell }) = pos {
+                    if let Some(cell) = cell {
+                        buffer.append(line_offset, ":", stylesheet.none);
+                        buffer.append(line_offset, &format!("cell {cell}"), stylesheet.none);
+                    }
                     buffer.append(line_offset, ":", stylesheet.none);
                     buffer.append(line_offset, row.to_string().as_str(), stylesheet.none);
+                    buffer.append(line_offset, ":", stylesheet.none);
+                    buffer.append(line_offset, col.to_string().as_str(), stylesheet.none);
                 }
                 Ok(())
             }
@@ -768,6 +825,7 @@ pub(crate) struct Annotation<'a> {
     pub(crate) annotation_type: DisplayAnnotationType,
     pub(crate) id: Option<&'a str>,
     pub(crate) label: Vec<DisplayTextFragment<'a>>,
+    pub(crate) is_fixable: bool,
 }
 
 /// A single line used in `DisplayList`.
@@ -833,6 +891,13 @@ impl DisplaySourceAnnotation<'_> {
     }
 }
 
+#[derive(Debug, PartialEq)]
+pub(crate) struct Position {
+    row: usize,
+    col: usize,
+    cell: Option<usize>,
+}
+
 /// Raw line - a line which does not have the `lineno` part and is not considered
 /// a part of the snippet.
 #[derive(Debug, PartialEq)]
@@ -841,7 +906,7 @@ pub(crate) enum DisplayRawLine<'a> {
     /// slice in the project structure.
     Origin {
         path: &'a str,
-        pos: Option<(usize, usize)>,
+        pos: Option<Position>,
         header_type: DisplayHeaderType,
     },
 
@@ -920,6 +985,13 @@ pub(crate) enum DisplayAnnotationType {
     Help,
 }
 
+impl DisplayAnnotationType {
+    #[inline]
+    const fn is_none(&self) -> bool {
+        matches!(self, Self::None)
+    }
+}
+
 impl From<snippet::Level> for DisplayAnnotationType {
     fn from(at: snippet::Level) -> Self {
         match at {
@@ -1015,11 +1087,12 @@ fn format_message<'m>(
         title,
         footer,
         snippets,
+        is_fixable,
     } = message;
 
     let mut sets = vec![];
     let body = if !snippets.is_empty() || primary {
-        vec![format_title(level, id, title)]
+        vec![format_title(level, id, title, is_fixable)]
     } else {
         format_footer(level, id, title)
     };
@@ -1060,12 +1133,18 @@ fn format_message<'m>(
     sets
 }
 
-fn format_title<'a>(level: crate::Level, id: Option<&'a str>, label: &'a str) -> DisplayLine<'a> {
+fn format_title<'a>(
+    level: crate::Level,
+    id: Option<&'a str>,
+    label: &'a str,
+    is_fixable: bool,
+) -> DisplayLine<'a> {
     DisplayLine::Raw(DisplayRawLine::Annotation {
         annotation: Annotation {
             annotation_type: DisplayAnnotationType::from(level),
             id,
             label: format_label(Some(label), Some(DisplayTextStyle::Emphasis)),
+            is_fixable,
         },
         source_aligned: false,
         continuation: false,
@@ -1084,6 +1163,7 @@ fn format_footer<'a>(
                 annotation_type: DisplayAnnotationType::from(level),
                 id,
                 label: format_label(Some(line), None),
+                is_fixable: false,
             },
             source_aligned: true,
             continuation: i != 0,
@@ -1118,6 +1198,23 @@ fn format_snippet<'m>(
     let main_range = snippet.annotations.first().map(|x| x.range.start);
     let origin = snippet.origin;
     let need_empty_header = origin.is_some() || is_first;
+
+    let is_file_level = snippet.annotations.iter().any(|ann| ann.is_file_level);
+    if is_file_level {
+        assert!(
+            snippet.source.is_empty(),
+            "Non-empty file-level snippet that won't be rendered: {:?}",
+            snippet.source
+        );
+        let header = format_header(origin, main_range, &[], is_first, snippet.cell_index);
+        return DisplaySet {
+            display_lines: header.map_or_else(Vec::new, |header| vec![header]),
+            margin: Margin::new(0, 0, 0, 0, term_width, 0),
+        };
+    }
+
+    let cell_index = snippet.cell_index;
+
     let mut body = format_body(
         snippet,
         need_empty_header,
@@ -1126,7 +1223,13 @@ fn format_snippet<'m>(
         anonymized_line_numbers,
         cut_indicator,
     );
-    let header = format_header(origin, main_range, &body.display_lines, is_first);
+    let header = format_header(
+        origin,
+        main_range,
+        &body.display_lines,
+        is_first,
+        cell_index,
+    );
 
     if let Some(header) = header {
         body.display_lines.insert(0, header);
@@ -1146,6 +1249,7 @@ fn format_header<'a>(
     main_range: Option<usize>,
     body: &[DisplayLine<'_>],
     is_first: bool,
+    cell_index: Option<usize>,
 ) -> Option<DisplayLine<'a>> {
     let display_header = if is_first {
         DisplayHeaderType::Initial
@@ -1182,7 +1286,11 @@ fn format_header<'a>(
 
         return Some(DisplayLine::Raw(DisplayRawLine::Origin {
             path,
-            pos: Some((line_offset, col)),
+            pos: Some(Position {
+                row: line_offset,
+                col,
+                cell: cell_index,
+            }),
             header_type: display_header,
         }));
     }
@@ -1472,6 +1580,7 @@ fn format_body<'m>(
                                 annotation_type,
                                 id: None,
                                 label: format_label(annotation.label, None),
+                                is_fixable: false,
                             },
                             range,
                             annotation_type: DisplayAnnotationType::from(annotation.level),
@@ -1511,6 +1620,7 @@ fn format_body<'m>(
                                 annotation_type,
                                 id: None,
                                 label: vec![],
+                                is_fixable: false,
                             },
                             range,
                             annotation_type: DisplayAnnotationType::from(annotation.level),
@@ -1580,6 +1690,7 @@ fn format_body<'m>(
                                 annotation_type,
                                 id: None,
                                 label: format_label(annotation.label, None),
+                                is_fixable: false,
                             },
                             range,
                             annotation_type: DisplayAnnotationType::from(annotation.level),

crates/ruff_annotate_snippets/src/snippet.rs

@@ -22,6 +22,7 @@ pub struct Message<'a> {
     pub(crate) title: &'a str,
     pub(crate) snippets: Vec<Snippet<'a>>,
     pub(crate) footer: Vec<Message<'a>>,
+    pub(crate) is_fixable: bool,
 }
 
 impl<'a> Message<'a> {
@@ -49,6 +50,15 @@ impl<'a> Message<'a> {
         self.footer.extend(footer);
         self
     }
+
+    /// Whether or not the diagnostic for this message is fixable.
+    ///
+    /// This is rendered as a `[*]` indicator after the `id` in an annotation header, if the
+    /// annotation also has `Level::None`.
+    pub fn is_fixable(mut self, yes: bool) -> Self {
+        self.is_fixable = yes;
+        self
+    }
 }
 
 /// Structure containing the slice of text to be annotated and
@@ -65,6 +75,10 @@ pub struct Snippet<'a> {
     pub(crate) annotations: Vec<Annotation<'a>>,
 
     pub(crate) fold: bool,
+
+    /// The optional cell index in a Jupyter notebook, used for reporting source locations along
+    /// with the ranges on `annotations`.
+    pub(crate) cell_index: Option<usize>,
 }
 
 impl<'a> Snippet<'a> {
@@ -75,6 +89,7 @@ impl<'a> Snippet<'a> {
             source,
             annotations: vec![],
             fold: false,
+            cell_index: None,
         }
     }
 
@@ -103,6 +118,12 @@ impl<'a> Snippet<'a> {
         self.fold = fold;
         self
     }
+
+    /// Attach a Jupyter notebook cell index.
+    pub fn cell_index(mut self, index: Option<usize>) -> Self {
+        self.cell_index = index;
+        self
+    }
 }
 
 /// An annotation for a [`Snippet`].
@@ -114,6 +135,7 @@ pub struct Annotation<'a> {
     pub(crate) range: Range<usize>,
     pub(crate) label: Option<&'a str>,
     pub(crate) level: Level,
+    pub(crate) is_file_level: bool,
 }
 
 impl<'a> Annotation<'a> {
@@ -121,6 +143,11 @@ impl<'a> Annotation<'a> {
         self.label = Some(label);
         self
     }
+
+    pub fn is_file_level(mut self, yes: bool) -> Self {
+        self.is_file_level = yes;
+        self
+    }
 }
 
 /// Types of annotations.
@@ -145,6 +172,7 @@ impl Level {
             title,
             snippets: vec![],
             footer: vec![],
+            is_fixable: false,
         }
     }
 
@@ -154,6 +182,7 @@ impl Level {
             range: span,
             label: None,
             level: self,
+            is_file_level: false,
         }
     }
 }

crates/ruff_benchmark/benches/ty.rs

@@ -18,7 +18,7 @@ use ruff_python_ast::PythonVersion;
 use ty_project::metadata::options::{EnvironmentOptions, Options};
 use ty_project::metadata::value::{RangedValue, RelativePathBuf};
 use ty_project::watch::{ChangeEvent, ChangedKind};
-use ty_project::{Db, ProjectDatabase, ProjectMetadata};
+use ty_project::{CheckMode, Db, ProjectDatabase, ProjectMetadata};
 
 struct Case {
     db: ProjectDatabase,
@@ -102,6 +102,7 @@ fn setup_tomllib_case() -> Case {
 
     let re = re.unwrap();
 
+    db.set_check_mode(CheckMode::OpenFiles);
     db.project().set_open_files(&mut db, tomllib_files);
 
     let re_path = re.path(&db).as_system_path().unwrap().to_owned();
@@ -237,6 +238,7 @@ fn setup_micro_case(code: &str) -> Case {
     let mut db = ProjectDatabase::new(metadata, system).unwrap();
     let file = system_path_to_file(&db, SystemPathBuf::from(file_path)).unwrap();
 
+    db.set_check_mode(CheckMode::OpenFiles);
     db.project()
         .set_open_files(&mut db, FxHashSet::from_iter([file]));
 
@@ -349,6 +351,41 @@ fn benchmark_many_tuple_assignments(criterion: &mut Criterion) {
     });
 }
 
+fn benchmark_tuple_implicit_instance_attributes(criterion: &mut Criterion) {
+    setup_rayon();
+
+    criterion.bench_function("ty_micro[many_tuple_assignments]", |b| {
+        b.iter_batched_ref(
+            || {
+                // This is a regression benchmark for a case that used to hang:
+                // https://github.com/astral-sh/ty/issues/765
+                setup_micro_case(
+                    r#"
+                    from typing import Any
+
+                    class A:
+                        foo: tuple[Any, ...]
+
+                    class B(A):
+                        def __init__(self, parent: "C", x: tuple[Any]):
+                            self.foo = parent.foo + x
+
+                    class C(A):
+                        def __init__(self, parent: B, x: tuple[Any]):
+                            self.foo = parent.foo + x
+                    "#,
+                )
+            },
+            |case| {
+                let Case { db, .. } = case;
+                let result = db.check();
+                assert_eq!(result.len(), 0);
+            },
+            BatchSize::SmallInput,
+        );
+    });
+}
+
 fn benchmark_complex_constrained_attributes_1(criterion: &mut Criterion) {
     setup_rayon();
 
@@ -525,14 +562,21 @@ impl<'a> ProjectBenchmark<'a> {
 
 #[track_caller]
 fn bench_project(benchmark: &ProjectBenchmark, criterion: &mut Criterion) {
-    fn check_project(db: &mut ProjectDatabase, max_diagnostics: usize) {
+    fn check_project(db: &mut ProjectDatabase, project_name: &str, max_diagnostics: usize) {
         let result = db.check();
         let diagnostics = result.len();
 
-        assert!(
-            diagnostics <= max_diagnostics,
-            "Expected <={max_diagnostics} diagnostics but got {diagnostics}"
-        );
+        if diagnostics > max_diagnostics {
+            let details = result
+                .into_iter()
+                .map(|diagnostic| diagnostic.concise_message().to_string())
+                .collect::<Vec<_>>()
+                .join("\n  ");
+            assert!(
+                diagnostics <= max_diagnostics,
+                "{project_name}: Expected <={max_diagnostics} diagnostics but got {diagnostics}:\n  {details}",
+            );
+        }
     }
 
     setup_rayon();
@@ -542,7 +586,7 @@ fn bench_project(benchmark: &ProjectBenchmark, criterion: &mut Criterion) {
     group.bench_function(benchmark.project.config.name, |b| {
         b.iter_batched_ref(
             || benchmark.setup_iteration(),
-            |db| check_project(db, benchmark.max_diagnostics),
+            |db| check_project(db, benchmark.project.config.name, benchmark.max_diagnostics),
             BatchSize::SmallInput,
         );
     });
@@ -610,7 +654,7 @@ fn datetype(criterion: &mut Criterion) {
             max_dep_date: "2025-07-04",
             python_version: PythonVersion::PY313,
         },
-        0,
+        2,
     );
 
     bench_project(&benchmark, criterion);
@@ -621,6 +665,7 @@ criterion_group!(
     micro,
     benchmark_many_string_assignments,
     benchmark_many_tuple_assignments,
+    benchmark_tuple_implicit_instance_attributes,
     benchmark_complex_constrained_attributes_1,
     benchmark_complex_constrained_attributes_2,
     benchmark_many_enum_members,

crates/ruff_db/Cargo.toml

@@ -14,6 +14,7 @@ license = { workspace = true }
 ruff_annotate_snippets = { workspace = true }
 ruff_cache = { workspace = true, optional = true }
 ruff_diagnostics = { workspace = true }
+ruff_memory_usage = { workspace = true }
 ruff_notebook = { workspace = true }
 ruff_python_ast = { workspace = true, features = ["get-size"] }
 ruff_python_parser = { workspace = true }
@@ -25,7 +26,6 @@ ty_static = { workspace = true }
 anstyle = { workspace = true }
 arc-swap = { workspace = true }
 camino = { workspace = true }
-countme = { workspace = true }
 dashmap = { workspace = true }
 dunce = { workspace = true }
 filetime = { workspace = true }
@@ -34,6 +34,7 @@ glob = { workspace = true }
 ignore = { workspace = true, optional = true }
 matchit = { workspace = true }
 path-slash = { workspace = true }
+quick-junit = { workspace = true, optional = true }
 rustc-hash = { workspace = true }
 salsa = { workspace = true }
 schemars = { workspace = true, optional = true }
@@ -56,7 +57,13 @@ tempfile = { workspace = true }
 
 [features]
 cache = ["ruff_cache"]
+junit = ["dep:quick-junit"]
 os = ["ignore", "dep:etcetera"]
-serde = ["camino/serde1", "dep:serde", "dep:serde_json", "ruff_diagnostics/serde"]
+serde = [
+    "camino/serde1",
+    "dep:serde",
+    "dep:serde_json",
+    "ruff_diagnostics/serde",
+]
 # Exposes testing utilities.
 testing = ["tracing-subscriber"]

crates/ruff_db/src/diagnostic/mod.rs

@@ -1,12 +1,14 @@
 use std::{fmt::Formatter, path::Path, sync::Arc};
 
-use ruff_diagnostics::Fix;
+use ruff_diagnostics::{Applicability, Fix};
 use ruff_source_file::{LineColumn, SourceCode, SourceFile};
 
 use ruff_annotate_snippets::Level as AnnotateLevel;
 use ruff_text_size::{Ranged, TextRange, TextSize};
 
-pub use self::render::{DisplayDiagnostic, DisplayDiagnostics, FileResolver, Input};
+pub use self::render::{
+    DisplayDiagnostic, DisplayDiagnostics, FileResolver, Input, ceil_char_boundary,
+};
 use crate::{Db, files::File};
 
 mod render;
@@ -19,7 +21,7 @@ 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, get_size2::GetSize)]
+#[derive(Debug, Clone, Eq, PartialEq, Hash, get_size2::GetSize)]
 pub struct Diagnostic {
     /// The actual diagnostic.
     ///
@@ -122,7 +124,14 @@ impl Diagnostic {
     /// directly. If callers want or need to avoid cloning the diagnostic
     /// message, then they can also pass a `DiagnosticMessage` directly.
     pub fn info<'a>(&mut self, message: impl IntoDiagnosticMessage + 'a) {
-        self.sub(SubDiagnostic::new(Severity::Info, message));
+        self.sub(SubDiagnostic::new(SubDiagnosticSeverity::Info, message));
+    }
+
+    /// Adds a "help" sub-diagnostic with the given message.
+    ///
+    /// See the closely related [`Diagnostic::info`] method for more details.
+    pub fn help<'a>(&mut self, message: impl IntoDiagnosticMessage + 'a) {
+        self.sub(SubDiagnostic::new(SubDiagnosticSeverity::Help, message));
     }
 
     /// Adds a "sub" diagnostic to this diagnostic.
@@ -203,7 +212,7 @@ impl Diagnostic {
     /// The type returned implements the `std::fmt::Display` trait. In most
     /// cases, just converting it to a string (or printing it) will do what
     /// you want.
-    pub fn concise_message(&self) -> ConciseMessage {
+    pub fn concise_message(&self) -> ConciseMessage<'_> {
         let main = self.inner.message.as_str();
         let annotation = self
             .primary_annotation()
@@ -357,6 +366,16 @@ impl Diagnostic {
         self.inner.secondary_code.as_ref()
     }
 
+    /// Returns the secondary code for the diagnostic if it exists, or the lint name otherwise.
+    ///
+    /// This is a common pattern for Ruff diagnostics, which want to use the noqa code in general,
+    /// but fall back on the `invalid-syntax` identifier for syntax errors, which don't have
+    /// secondary codes.
+    pub fn secondary_code_or_id(&self) -> &str {
+        self.secondary_code()
+            .map_or_else(|| self.inner.id.as_str(), SecondaryCode::as_str)
+    }
+
     /// Set the secondary code for this diagnostic.
     pub fn set_secondary_code(&mut self, code: SecondaryCode) {
         Arc::make_mut(&mut self.inner).secondary_code = Some(code);
@@ -377,9 +396,15 @@ impl Diagnostic {
         self.primary_message()
     }
 
-    /// Returns the fix suggestion for the violation.
-    pub fn suggestion(&self) -> Option<&str> {
-        self.primary_annotation()?.get_message()
+    /// Returns the message of the first sub-diagnostic with a `Help` severity.
+    ///
+    /// Note that this is used as the fix title/suggestion for some of Ruff's output formats, but in
+    /// general this is not the guaranteed meaning of such a message.
+    pub fn first_help_text(&self) -> Option<&str> {
+        self.sub_diagnostics()
+            .iter()
+            .find(|sub| matches!(sub.inner.severity, SubDiagnosticSeverity::Help))
+            .map(|sub| sub.inner.message.as_str())
     }
 
     /// Returns the URL for the rule documentation, if it exists.
@@ -464,7 +489,7 @@ impl Diagnostic {
     }
 }
 
-#[derive(Debug, Clone, Eq, PartialEq, get_size2::GetSize)]
+#[derive(Debug, Clone, Eq, PartialEq, Hash, get_size2::GetSize)]
 struct DiagnosticInner {
     id: DiagnosticId,
     severity: Severity,
@@ -540,7 +565,7 @@ 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, get_size2::GetSize)]
+#[derive(Debug, Clone, Eq, PartialEq, Hash, get_size2::GetSize)]
 pub struct SubDiagnostic {
     /// Like with `Diagnostic`, we box the `SubDiagnostic` to make it
     /// pointer-sized.
@@ -565,7 +590,10 @@ impl SubDiagnostic {
     /// Callers can pass anything that implements `std::fmt::Display`
     /// directly. If callers want or need to avoid cloning the diagnostic
     /// message, then they can also pass a `DiagnosticMessage` directly.
-    pub fn new<'a>(severity: Severity, message: impl IntoDiagnosticMessage + 'a) -> SubDiagnostic {
+    pub fn new<'a>(
+        severity: SubDiagnosticSeverity,
+        message: impl IntoDiagnosticMessage + 'a,
+    ) -> SubDiagnostic {
         let inner = Box::new(SubDiagnosticInner {
             severity,
             message: message.into_diagnostic_message(),
@@ -626,7 +654,7 @@ impl SubDiagnostic {
     /// The type returned implements the `std::fmt::Display` trait. In most
     /// cases, just converting it to a string (or printing it) will do what
     /// you want.
-    pub fn concise_message(&self) -> ConciseMessage {
+    pub fn concise_message(&self) -> ConciseMessage<'_> {
         let main = self.inner.message.as_str();
         let annotation = self
             .primary_annotation()
@@ -641,9 +669,9 @@ impl SubDiagnostic {
     }
 }
 
-#[derive(Debug, Clone, Eq, PartialEq, get_size2::GetSize)]
+#[derive(Debug, Clone, Eq, PartialEq, Hash, get_size2::GetSize)]
 struct SubDiagnosticInner {
-    severity: Severity,
+    severity: SubDiagnosticSeverity,
     message: DiagnosticMessage,
     annotations: Vec<Annotation>,
 }
@@ -669,7 +697,7 @@ 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, get_size2::GetSize)]
+#[derive(Debug, Clone, Eq, PartialEq, Hash, 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.
@@ -684,6 +712,11 @@ pub struct Annotation {
     is_primary: bool,
     /// The diagnostic tags associated with this annotation.
     tags: Vec<DiagnosticTag>,
+    /// Whether this annotation is a file-level or full-file annotation.
+    ///
+    /// When set, rendering will only include the file's name and (optional) range. Everything else
+    /// is omitted, including any file snippet or message.
+    is_file_level: bool,
 }
 
 impl Annotation {
@@ -702,6 +735,7 @@ impl Annotation {
             message: None,
             is_primary: true,
             tags: Vec::new(),
+            is_file_level: false,
         }
     }
 
@@ -718,6 +752,7 @@ impl Annotation {
             message: None,
             is_primary: false,
             tags: Vec::new(),
+            is_file_level: false,
         }
     }
 
@@ -783,13 +818,28 @@ impl Annotation {
     pub fn push_tag(&mut self, tag: DiagnosticTag) {
         self.tags.push(tag);
     }
+
+    /// Set whether or not this annotation is file-level.
+    ///
+    /// File-level annotations are only rendered with their file name and range, if available. This
+    /// is intended for backwards compatibility with Ruff diagnostics, which historically used
+    /// `TextRange::default` to indicate a file-level diagnostic. In the new diagnostic model, a
+    /// [`Span`] with a range of `None` should be used instead, as mentioned in the `Span`
+    /// documentation.
+    ///
+    /// TODO(brent) update this usage in Ruff and remove `is_file_level` entirely. See
+    /// <https://github.com/astral-sh/ruff/issues/19688>, especially my first comment, for more
+    /// details.
+    pub fn set_file_level(&mut self, yes: bool) {
+        self.is_file_level = yes;
+    }
 }
 
 /// Tags that can be associated with an annotation.
 ///
 /// These tags are used to provide additional information about the annotation.
 /// and are passed through to the language server protocol.
-#[derive(Debug, Clone, Eq, PartialEq, get_size2::GetSize)]
+#[derive(Debug, Clone, Eq, PartialEq, Hash, get_size2::GetSize)]
 pub enum DiagnosticTag {
     /// Unused or unnecessary code. Used for unused parameters, unreachable code, etc.
     Unnecessary,
@@ -998,7 +1048,7 @@ 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, get_size2::GetSize)]
+#[derive(Debug, Clone, PartialEq, Eq, Hash, get_size2::GetSize)]
 pub enum UnifiedFile {
     Ty(File),
     Ruff(SourceFile),
@@ -1049,7 +1099,7 @@ enum DiagnosticSource {
 
 impl DiagnosticSource {
     /// Returns this input as a `SourceCode` for convenient querying.
-    fn as_source_code(&self) -> SourceCode {
+    fn as_source_code(&self) -> SourceCode<'_, '_> {
         match self {
             DiagnosticSource::Ty(input) => SourceCode::new(input.text.as_str(), &input.line_index),
             DiagnosticSource::Ruff(source) => SourceCode::new(source.source_text(), source.index()),
@@ -1062,7 +1112,7 @@ 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, get_size2::GetSize)]
+#[derive(Debug, Clone, PartialEq, Eq, Hash, get_size2::GetSize)]
 pub struct Span {
     file: UnifiedFile,
     range: Option<TextRange>,
@@ -1140,7 +1190,7 @@ impl From<crate::files::FileRange> for Span {
     }
 }
 
-#[derive(Debug, Clone, Copy, PartialEq, Eq, Ord, PartialOrd, get_size2::GetSize)]
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Ord, PartialOrd, Hash, get_size2::GetSize)]
 pub enum Severity {
     Info,
     Warning,
@@ -1170,6 +1220,32 @@ impl Severity {
     }
 }
 
+/// Like [`Severity`] but exclusively for sub-diagnostics.
+///
+/// This type only exists to add an additional `Help` severity that isn't present in `Severity` or
+/// used for main diagnostics. If we want to add `Severity::Help` in the future, this type could be
+/// deleted and the two combined again.
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Ord, PartialOrd, Hash, get_size2::GetSize)]
+pub enum SubDiagnosticSeverity {
+    Help,
+    Info,
+    Warning,
+    Error,
+    Fatal,
+}
+
+impl SubDiagnosticSeverity {
+    fn to_annotate(self) -> AnnotateLevel {
+        match self {
+            SubDiagnosticSeverity::Help => AnnotateLevel::Help,
+            SubDiagnosticSeverity::Info => AnnotateLevel::Info,
+            SubDiagnosticSeverity::Warning => AnnotateLevel::Warning,
+            SubDiagnosticSeverity::Error => AnnotateLevel::Error,
+            SubDiagnosticSeverity::Fatal => AnnotateLevel::Error,
+        }
+    }
+}
+
 /// Configuration for rendering diagnostics.
 #[derive(Clone, Debug)]
 pub struct DisplayDiagnosticConfig {
@@ -1196,6 +1272,15 @@ pub struct DisplayDiagnosticConfig {
         reason = "This is currently only used for JSON but will be needed soon for other formats"
     )]
     preview: bool,
+    /// Whether to hide the real `Severity` of diagnostics.
+    ///
+    /// This is intended for temporary use by Ruff, which only has a single `error` severity at the
+    /// moment. We should be able to remove this option when Ruff gets more severities.
+    hide_severity: bool,
+    /// Whether to show the availability of a fix in a diagnostic.
+    show_fix_status: bool,
+    /// The lowest applicability that should be shown when reporting diagnostics.
+    fix_applicability: Applicability,
 }
 
 impl DisplayDiagnosticConfig {
@@ -1224,6 +1309,35 @@ impl DisplayDiagnosticConfig {
             ..self
         }
     }
+
+    /// Whether to hide a diagnostic's severity or not.
+    pub fn hide_severity(self, yes: bool) -> DisplayDiagnosticConfig {
+        DisplayDiagnosticConfig {
+            hide_severity: yes,
+            ..self
+        }
+    }
+
+    /// Whether to show a fix's availability or not.
+    pub fn show_fix_status(self, yes: bool) -> DisplayDiagnosticConfig {
+        DisplayDiagnosticConfig {
+            show_fix_status: yes,
+            ..self
+        }
+    }
+
+    /// Set the lowest fix applicability that should be shown.
+    ///
+    /// In other words, an applicability of `Safe` (the default) would suppress showing fixes or fix
+    /// availability for unsafe or display-only fixes.
+    ///
+    /// Note that this option is currently ignored when `hide_severity` is false.
+    pub fn fix_applicability(self, applicability: Applicability) -> DisplayDiagnosticConfig {
+        DisplayDiagnosticConfig {
+            fix_applicability: applicability,
+            ..self
+        }
+    }
 }
 
 impl Default for DisplayDiagnosticConfig {
@@ -1233,6 +1347,9 @@ impl Default for DisplayDiagnosticConfig {
             color: false,
             context: 2,
             preview: false,
+            hide_severity: false,
+            show_fix_status: false,
+            fix_applicability: Applicability::Safe,
         }
     }
 }
@@ -1282,6 +1399,9 @@ pub enum DiagnosticFormat {
     Rdjson,
     /// Print diagnostics in the format emitted by Pylint.
     Pylint,
+    /// Print diagnostics in the format expected by JUnit.
+    #[cfg(feature = "junit")]
+    Junit,
 }
 
 /// A representation of the kinds of messages inside a diagnostic.
@@ -1340,7 +1460,7 @@ 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, get_size2::GetSize)]
+#[derive(Clone, Debug, Eq, PartialEq, Hash, get_size2::GetSize)]
 pub struct DiagnosticMessage(Box<str>);
 
 impl DiagnosticMessage {

crates/ruff_db/src/diagnostic/render.rs

@@ -1,3 +1,4 @@
+use std::borrow::Cow;
 use std::collections::BTreeMap;
 use std::path::Path;
 
@@ -7,9 +8,9 @@ use ruff_annotate_snippets::{
 };
 use ruff_notebook::{Notebook, NotebookIndex};
 use ruff_source_file::{LineIndex, OneIndexed, SourceCode};
-use ruff_text_size::{TextRange, TextSize};
+use ruff_text_size::{TextLen, TextRange, TextSize};
 
-use crate::diagnostic::stylesheet::{DiagnosticStylesheet, fmt_styled};
+use crate::diagnostic::stylesheet::DiagnosticStylesheet;
 use crate::{
     Db,
     files::File,
@@ -18,18 +19,23 @@ use crate::{
 };
 
 use super::{
-    Annotation, Diagnostic, DiagnosticFormat, DiagnosticSource, DisplayDiagnosticConfig, Severity,
+    Annotation, Diagnostic, DiagnosticFormat, DiagnosticSource, DisplayDiagnosticConfig,
     SubDiagnostic, UnifiedFile,
 };
 
 use azure::AzureRenderer;
+use concise::ConciseRenderer;
 use pylint::PylintRenderer;
 
 mod azure;
+mod concise;
+mod full;
 #[cfg(feature = "serde")]
 mod json;
 #[cfg(feature = "serde")]
 mod json_lines;
+#[cfg(feature = "junit")]
+mod junit;
 mod pylint;
 #[cfg(feature = "serde")]
 mod rdjson;
@@ -102,48 +108,7 @@ impl std::fmt::Display for DisplayDiagnostics<'_> {
     fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
         match self.config.format {
             DiagnosticFormat::Concise => {
-                let stylesheet = if self.config.color {
-                    DiagnosticStylesheet::styled()
-                } else {
-                    DiagnosticStylesheet::plain()
-                };
-
-                for diag in self.diagnostics {
-                    let (severity, severity_style) = match diag.severity() {
-                        Severity::Info => ("info", stylesheet.info),
-                        Severity::Warning => ("warning", stylesheet.warning),
-                        Severity::Error => ("error", stylesheet.error),
-                        Severity::Fatal => ("fatal", stylesheet.error),
-                    };
-                    write!(
-                        f,
-                        "{severity}[{id}]",
-                        severity = fmt_styled(severity, severity_style),
-                        id = fmt_styled(diag.id(), stylesheet.emphasis)
-                    )?;
-                    if let Some(span) = diag.primary_span() {
-                        write!(
-                            f,
-                            " {path}",
-                            path = fmt_styled(span.file().path(self.resolver), stylesheet.emphasis)
-                        )?;
-                        if let Some(range) = span.range() {
-                            let diagnostic_source = span.file().diagnostic_source(self.resolver);
-                            let start = diagnostic_source
-                                .as_source_code()
-                                .line_column(range.start());
-
-                            write!(
-                                f,
-                                ":{line}:{col}",
-                                line = fmt_styled(start.line, stylesheet.emphasis),
-                                col = fmt_styled(start.column, stylesheet.emphasis),
-                            )?;
-                        }
-                        write!(f, ":")?;
-                    }
-                    writeln!(f, " {message}", message = diag.concise_message())?;
-                }
+                ConciseRenderer::new(self.resolver, self.config).render(f, self.diagnostics)?;
             }
             DiagnosticFormat::Full => {
                 let stylesheet = if self.config.color {
@@ -156,7 +121,8 @@ impl std::fmt::Display for DisplayDiagnostics<'_> {
                     AnnotateRenderer::styled()
                 } else {
                     AnnotateRenderer::plain()
-                };
+                }
+                .cut_indicator("…");
 
                 renderer = renderer
                     .error(stylesheet.error)
@@ -169,7 +135,7 @@ impl std::fmt::Display for DisplayDiagnostics<'_> {
                     .none(stylesheet.none);
 
                 for diag in self.diagnostics {
-                    let resolved = Resolved::new(self.resolver, diag);
+                    let resolved = Resolved::new(self.resolver, diag, self.config);
                     let renderable = resolved.to_renderable(self.config.context);
                     for diag in renderable.diagnostics.iter() {
                         writeln!(f, "{}", renderer.render(diag.to_annotate()))?;
@@ -196,6 +162,10 @@ impl std::fmt::Display for DisplayDiagnostics<'_> {
             DiagnosticFormat::Pylint => {
                 PylintRenderer::new(self.resolver).render(f, self.diagnostics)?;
             }
+            #[cfg(feature = "junit")]
+            DiagnosticFormat::Junit => {
+                junit::JunitRenderer::new(self.resolver).render(f, self.diagnostics)?;
+            }
         }
 
         Ok(())
@@ -221,9 +191,13 @@ struct Resolved<'a> {
 
 impl<'a> Resolved<'a> {
     /// Creates a new resolved set of diagnostics.
-    fn new(resolver: &'a dyn FileResolver, diag: &'a Diagnostic) -> Resolved<'a> {
+    fn new(
+        resolver: &'a dyn FileResolver,
+        diag: &'a Diagnostic,
+        config: &DisplayDiagnosticConfig,
+    ) -> Resolved<'a> {
         let mut diagnostics = vec![];
-        diagnostics.push(ResolvedDiagnostic::from_diagnostic(resolver, diag));
+        diagnostics.push(ResolvedDiagnostic::from_diagnostic(resolver, config, diag));
         for sub in &diag.inner.subs {
             diagnostics.push(ResolvedDiagnostic::from_sub_diagnostic(resolver, sub));
         }
@@ -249,16 +223,18 @@ impl<'a> Resolved<'a> {
 /// both.)
 #[derive(Debug)]
 struct ResolvedDiagnostic<'a> {
-    severity: Severity,
+    level: AnnotateLevel,
     id: Option<String>,
     message: String,
     annotations: Vec<ResolvedAnnotation<'a>>,
+    is_fixable: bool,
 }
 
 impl<'a> ResolvedDiagnostic<'a> {
     /// Resolve a single diagnostic.
     fn from_diagnostic(
         resolver: &'a dyn FileResolver,
+        config: &DisplayDiagnosticConfig,
         diag: &'a Diagnostic,
     ) -> ResolvedDiagnostic<'a> {
         let annotations: Vec<_> = diag
@@ -268,16 +244,38 @@ impl<'a> ResolvedDiagnostic<'a> {
             .filter_map(|ann| {
                 let path = ann.span.file.path(resolver);
                 let diagnostic_source = ann.span.file.diagnostic_source(resolver);
-                ResolvedAnnotation::new(path, &diagnostic_source, ann)
+                ResolvedAnnotation::new(path, &diagnostic_source, ann, resolver)
             })
             .collect();
-        let id = Some(diag.inner.id.to_string());
-        let message = diag.inner.message.as_str().to_string();
+
+        let id = if config.hide_severity {
+            // Either the rule code alone (e.g. `F401`), or the lint id with a colon (e.g.
+            // `invalid-syntax:`). When Ruff gets real severities, we should put the colon back in
+            // `DisplaySet::format_annotation` for both cases, but this is a small hack to improve
+            // the formatting of syntax errors for now. This should also be kept consistent with the
+            // concise formatting.
+            Some(diag.secondary_code().map_or_else(
+                || format!("{id}:", id = diag.inner.id),
+                |code| code.to_string(),
+            ))
+        } else {
+            Some(diag.inner.id.to_string())
+        };
+
+        let level = if config.hide_severity {
+            AnnotateLevel::None
+        } else {
+            diag.inner.severity.to_annotate()
+        };
+
         ResolvedDiagnostic {
-            severity: diag.inner.severity,
+            level,
             id,
-            message,
+            message: diag.inner.message.as_str().to_string(),
             annotations,
+            is_fixable: diag
+                .fix()
+                .is_some_and(|fix| fix.applies(config.fix_applicability)),
         }
     }
 
@@ -293,14 +291,15 @@ impl<'a> ResolvedDiagnostic<'a> {
             .filter_map(|ann| {
                 let path = ann.span.file.path(resolver);
                 let diagnostic_source = ann.span.file.diagnostic_source(resolver);
-                ResolvedAnnotation::new(path, &diagnostic_source, ann)
+                ResolvedAnnotation::new(path, &diagnostic_source, ann, resolver)
             })
             .collect();
         ResolvedDiagnostic {
-            severity: diag.inner.severity,
+            level: diag.inner.severity.to_annotate(),
             id: None,
             message: diag.inner.message.as_str().to_string(),
             annotations,
+            is_fixable: false,
         }
     }
 
@@ -331,20 +330,49 @@ impl<'a> ResolvedDiagnostic<'a> {
                     &prev.diagnostic_source.as_source_code(),
                     context,
                     prev.line_end,
+                    prev.notebook_index.as_ref(),
                 )
                 .get();
                 let this_context_begins = context_before(
                     &ann.diagnostic_source.as_source_code(),
                     context,
                     ann.line_start,
+                    ann.notebook_index.as_ref(),
                 )
                 .get();
+
+                // For notebooks, check whether the end of the
+                // previous annotation and the start of the current
+                // annotation are in different cells.
+                let prev_cell_index = prev.notebook_index.as_ref().map(|notebook_index| {
+                    let prev_end = prev
+                        .diagnostic_source
+                        .as_source_code()
+                        .line_column(prev.range.end());
+                    notebook_index.cell(prev_end.line).unwrap_or_default().get()
+                });
+                let this_cell_index = ann.notebook_index.as_ref().map(|notebook_index| {
+                    let this_start = ann
+                        .diagnostic_source
+                        .as_source_code()
+                        .line_column(ann.range.start());
+                    notebook_index
+                        .cell(this_start.line)
+                        .unwrap_or_default()
+                        .get()
+                });
+                let in_different_cells = prev_cell_index != this_cell_index;
+
                 // The boundary case here is when `prev_context_ends`
                 // is exactly one less than `this_context_begins`. In
                 // that case, the context windows are adjacent and we
                 // should fall through below to add this annotation to
                 // the existing snippet.
-                if this_context_begins.saturating_sub(prev_context_ends) > 1 {
+                //
+                // For notebooks, also check that the context windows
+                // are in the same cell. Windows from different cells
+                // should never be considered adjacent.
+                if in_different_cells || this_context_begins.saturating_sub(prev_context_ends) > 1 {
                     snippet_by_path
                         .entry(path)
                         .or_default()
@@ -364,10 +392,11 @@ impl<'a> ResolvedDiagnostic<'a> {
         snippets_by_input
             .sort_by(|snips1, snips2| snips1.has_primary.cmp(&snips2.has_primary).reverse());
         RenderableDiagnostic {
-            severity: self.severity,
+            level: self.level,
             id: self.id.as_deref(),
             message: &self.message,
             snippets_by_input,
+            is_fixable: self.is_fixable,
         }
     }
 }
@@ -387,6 +416,8 @@ struct ResolvedAnnotation<'a> {
     line_end: OneIndexed,
     message: Option<&'a str>,
     is_primary: bool,
+    is_file_level: bool,
+    notebook_index: Option<NotebookIndex>,
 }
 
 impl<'a> ResolvedAnnotation<'a> {
@@ -399,6 +430,7 @@ impl<'a> ResolvedAnnotation<'a> {
         path: &'a str,
         diagnostic_source: &DiagnosticSource,
         ann: &'a Annotation,
+        resolver: &'a dyn FileResolver,
     ) -> Option<ResolvedAnnotation<'a>> {
         let source = diagnostic_source.as_source_code();
         let (range, line_start, line_end) = match (ann.span.range(), ann.message.is_some()) {
@@ -432,6 +464,8 @@ impl<'a> ResolvedAnnotation<'a> {
             line_end,
             message: ann.get_message(),
             is_primary: ann.is_primary,
+            is_file_level: ann.is_file_level,
+            notebook_index: resolver.notebook_index(&ann.span.file),
         })
     }
 }
@@ -452,7 +486,7 @@ struct Renderable<'r> {
 #[derive(Debug)]
 struct RenderableDiagnostic<'r> {
     /// The severity of the diagnostic.
-    severity: Severity,
+    level: AnnotateLevel,
     /// The ID of the diagnostic. The ID can usually be used on the CLI or in a
     /// config file to change the severity of a lint.
     ///
@@ -466,12 +500,15 @@ struct RenderableDiagnostic<'r> {
     /// should be from the same file, and none of the snippets inside of a
     /// collection should overlap with one another or be directly adjacent.
     snippets_by_input: Vec<RenderableSnippets<'r>>,
+    /// Whether or not the diagnostic is fixable.
+    ///
+    /// This is rendered as a `[*]` indicator after the diagnostic ID.
+    is_fixable: bool,
 }
 
 impl RenderableDiagnostic<'_> {
     /// Convert this to an "annotate" snippet.
     fn to_annotate(&self) -> AnnotateMessage<'_> {
-        let level = self.severity.to_annotate();
         let snippets = self.snippets_by_input.iter().flat_map(|snippets| {
             let path = snippets.path;
             snippets
@@ -479,7 +516,7 @@ impl RenderableDiagnostic<'_> {
                 .iter()
                 .map(|snippet| snippet.to_annotate(path))
         });
-        let mut message = level.title(self.message);
+        let mut message = self.level.title(self.message).is_fixable(self.is_fixable);
         if let Some(id) = self.id {
             message = message.id(id);
         }
@@ -552,7 +589,7 @@ impl<'r> RenderableSnippets<'r> {
 #[derive(Debug)]
 struct RenderableSnippet<'r> {
     /// The actual snippet text.
-    snippet: &'r str,
+    snippet: Cow<'r, str>,
     /// The absolute line number corresponding to where this
     /// snippet begins.
     line_start: OneIndexed,
@@ -561,17 +598,27 @@ struct RenderableSnippet<'r> {
     /// Whether this snippet contains at least one primary
     /// annotation.
     has_primary: bool,
+    /// The cell index in a Jupyter notebook, if this snippet refers to a notebook.
+    ///
+    /// This is used for rendering annotations with offsets like `cell 1:2:3` instead of simple row
+    /// and column numbers.
+    cell_index: Option<usize>,
 }
 
 impl<'r> RenderableSnippet<'r> {
     /// Creates a new snippet with one or more annotations that is ready to be
-    /// renderer.
+    /// rendered.
     ///
     /// The first line of the snippet is the smallest line number on which one
     /// of the annotations begins, minus the context window size. The last line
     /// is the largest line number on which one of the annotations ends, plus
     /// the context window size.
     ///
+    /// For Jupyter notebooks, the context window may also be truncated at cell
+    /// boundaries. If multiple annotations are present, and they point to
+    /// different cells, these will have already been split into separate
+    /// snippets by `ResolvedDiagnostic::to_renderable`.
+    ///
     /// Callers should guarantee that the `input` on every `ResolvedAnnotation`
     /// given is identical.
     ///
@@ -588,19 +635,19 @@ impl<'r> RenderableSnippet<'r> {
             "creating a renderable snippet requires a non-zero number of annotations",
         );
         let diagnostic_source = &anns[0].diagnostic_source;
+        let notebook_index = anns[0].notebook_index.as_ref();
         let source = diagnostic_source.as_source_code();
         let has_primary = anns.iter().any(|ann| ann.is_primary);
 
-        let line_start = context_before(
-            &source,
-            context,
-            anns.iter().map(|ann| ann.line_start).min().unwrap(),
-        );
-        let line_end = context_after(
-            &source,
-            context,
-            anns.iter().map(|ann| ann.line_end).max().unwrap(),
-        );
+        let content_start_index = anns.iter().map(|ann| ann.line_start).min().unwrap();
+        let line_start = context_before(&source, context, content_start_index, notebook_index);
+
+        let start = source.line_column(anns[0].range.start());
+        let cell_index = notebook_index
+            .map(|notebook_index| notebook_index.cell(start.line).unwrap_or_default().get());
+
+        let content_end_index = anns.iter().map(|ann| ann.line_end).max().unwrap();
+        let line_end = context_after(&source, context, content_end_index, notebook_index);
 
         let snippet_start = source.line_start(line_start);
         let snippet_end = source.line_end(line_end);
@@ -612,17 +659,30 @@ impl<'r> RenderableSnippet<'r> {
             .iter()
             .map(|ann| RenderableAnnotation::new(snippet_start, ann))
             .collect();
+
+        let EscapedSourceCode {
+            text: snippet,
+            annotations,
+        } = replace_unprintable(snippet, annotations).fix_up_empty_spans_after_line_terminator();
+
+        let line_start = notebook_index.map_or(line_start, |notebook_index| {
+            notebook_index
+                .cell_row(line_start)
+                .unwrap_or(OneIndexed::MIN)
+        });
+
         RenderableSnippet {
             snippet,
             line_start,
             annotations,
             has_primary,
+            cell_index,
         }
     }
 
     /// Convert this to an "annotate" snippet.
     fn to_annotate<'a>(&'a self, path: &'a str) -> AnnotateSnippet<'a> {
-        AnnotateSnippet::source(self.snippet)
+        AnnotateSnippet::source(&self.snippet)
             .origin(path)
             .line_start(self.line_start.get())
             .annotations(
@@ -630,6 +690,7 @@ impl<'r> RenderableSnippet<'r> {
                     .iter()
                     .map(RenderableAnnotation::to_annotate),
             )
+            .cell_index(self.cell_index)
     }
 }
 
@@ -644,6 +705,8 @@ struct RenderableAnnotation<'r> {
     message: Option<&'r str>,
     /// Whether this annotation is considered "primary" or not.
     is_primary: bool,
+    /// Whether this annotation applies to an entire file, rather than a snippet within it.
+    is_file_level: bool,
 }
 
 impl<'r> RenderableAnnotation<'r> {
@@ -661,6 +724,7 @@ impl<'r> RenderableAnnotation<'r> {
             range,
             message: ann.message,
             is_primary: ann.is_primary,
+            is_file_level: ann.is_file_level,
         }
     }
 
@@ -686,7 +750,7 @@ impl<'r> RenderableAnnotation<'r> {
         if let Some(message) = self.message {
             ann = ann.label(message);
         }
-        ann
+        ann.is_file_level(self.is_file_level)
     }
 }
 
@@ -813,7 +877,15 @@ pub struct Input {
 ///
 /// The line number returned is guaranteed to be less than
 /// or equal to `start`.
-fn context_before(source: &SourceCode<'_, '_>, len: usize, start: OneIndexed) -> OneIndexed {
+///
+/// In Jupyter notebooks, lines outside the cell containing
+/// `start` will be omitted.
+fn context_before(
+    source: &SourceCode<'_, '_>,
+    len: usize,
+    start: OneIndexed,
+    notebook_index: Option<&NotebookIndex>,
+) -> OneIndexed {
     let mut line = start.saturating_sub(len);
     // Trim leading empty lines.
     while line < start {
@@ -822,6 +894,17 @@ fn context_before(source: &SourceCode<'_, '_>, len: usize, start: OneIndexed) ->
         }
         line = line.saturating_add(1);
     }
+
+    if let Some(index) = notebook_index {
+        let content_start_cell = index.cell(start).unwrap_or(OneIndexed::MIN);
+        while line < start {
+            if index.cell(line).unwrap_or(OneIndexed::MIN) == content_start_cell {
+                break;
+            }
+            line = line.saturating_add(1);
+        }
+    }
+
     line
 }
 
@@ -831,7 +914,15 @@ fn context_before(source: &SourceCode<'_, '_>, len: usize, start: OneIndexed) ->
 /// The line number returned is guaranteed to be greater
 /// than or equal to `start` and no greater than the
 /// number of lines in `source`.
-fn context_after(source: &SourceCode<'_, '_>, len: usize, start: OneIndexed) -> OneIndexed {
+///
+/// In Jupyter notebooks, lines outside the cell containing
+/// `start` will be omitted.
+fn context_after(
+    source: &SourceCode<'_, '_>,
+    len: usize,
+    start: OneIndexed,
+    notebook_index: Option<&NotebookIndex>,
+) -> OneIndexed {
     let max_lines = OneIndexed::from_zero_indexed(source.line_count());
     let mut line = start.saturating_add(len).min(max_lines);
     // Trim trailing empty lines.
@@ -841,6 +932,17 @@ fn context_after(source: &SourceCode<'_, '_>, len: usize, start: OneIndexed) ->
         }
         line = line.saturating_sub(1);
     }
+
+    if let Some(index) = notebook_index {
+        let content_end_cell = index.cell(start).unwrap_or(OneIndexed::MIN);
+        while line > start {
+            if index.cell(line).unwrap_or(OneIndexed::MIN) == content_end_cell {
+                break;
+            }
+            line = line.saturating_sub(1);
+        }
+    }
+
     line
 }
 
@@ -852,12 +954,213 @@ fn relativize_path<'p>(cwd: &SystemPath, path: &'p str) -> &'p str {
     path
 }
 
+/// Given some source code and annotation ranges, this routine replaces
+/// unprintable characters with printable representations of them.
+///
+/// The source code and annotations returned are updated to reflect changes made
+/// to the source code (if any).
+///
+/// We don't need to normalize whitespace, such as converting tabs to spaces,
+/// because `annotate-snippets` handles that internally. Similarly, it's safe to
+/// modify the annotation ranges by inserting 3-byte Unicode replacements
+/// because `annotate-snippets` will account for their actual width when
+/// rendering and displaying the column to the user.
+fn replace_unprintable<'r>(
+    source: &'r str,
+    mut annotations: Vec<RenderableAnnotation<'r>>,
+) -> EscapedSourceCode<'r> {
+    // Updates the annotation ranges given by the caller whenever a single byte (at `index` in
+    // `source`) is replaced with `len` bytes.
+    //
+    // When the index occurs before the start of the range, the range is
+    // offset by `len`. When the range occurs after or at the start but before
+    // the end, then the end of the range only is offset by `len`.
+    let mut update_ranges = |index: usize, len: u32| {
+        for ann in &mut annotations {
+            if index < usize::from(ann.range.start()) {
+                ann.range += TextSize::new(len - 1);
+            } else if index < usize::from(ann.range.end()) {
+                ann.range = ann.range.add_end(TextSize::new(len - 1));
+            }
+        }
+    };
+
+    // If `c` is an unprintable character, then this returns a printable
+    // representation of it (using a fancier Unicode codepoint).
+    let unprintable_replacement = |c: char| -> Option<char> {
+        match c {
+            '\x07' => Some('␇'),
+            '\x08' => Some('␈'),
+            '\x1b' => Some('␛'),
+            '\x7f' => Some('␡'),
+            _ => None,
+        }
+    };
+
+    let mut last_end = 0;
+    let mut result = String::new();
+    for (index, c) in source.char_indices() {
+        if let Some(printable) = unprintable_replacement(c) {
+            result.push_str(&source[last_end..index]);
+
+            let len = printable.text_len().to_u32();
+            update_ranges(result.text_len().to_usize(), len);
+
+            result.push(printable);
+            last_end = index + 1;
+        }
+    }
+
+    // No tabs or unprintable chars
+    if result.is_empty() {
+        EscapedSourceCode {
+            annotations,
+            text: Cow::Borrowed(source),
+        }
+    } else {
+        result.push_str(&source[last_end..]);
+        EscapedSourceCode {
+            annotations,
+            text: Cow::Owned(result),
+        }
+    }
+}
+
+struct EscapedSourceCode<'r> {
+    text: Cow<'r, str>,
+    annotations: Vec<RenderableAnnotation<'r>>,
+}
+
+impl<'r> EscapedSourceCode<'r> {
+    // This attempts to "fix up" the spans on each annotation  in the case where
+    // it's an empty span immediately following a line terminator.
+    //
+    // At present, `annotate-snippets` (both upstream and our vendored copy)
+    // will render annotations of such spans to point to the space immediately
+    // following the previous line. But ideally, this should point to the space
+    // immediately preceding the next line.
+    //
+    // After attempting to fix `annotate-snippets` and giving up after a couple
+    // hours, this routine takes a different tact: it adjusts the span to be
+    // non-empty and it will cover the first codepoint of the following line.
+    // This forces `annotate-snippets` to point to the right place.
+    //
+    // See also: <https://github.com/astral-sh/ruff/issues/15509> and
+    // `ruff_linter::message::text::SourceCode::fix_up_empty_spans_after_line_terminator`,
+    // from which this was adapted.
+    fn fix_up_empty_spans_after_line_terminator(mut self) -> EscapedSourceCode<'r> {
+        for ann in &mut self.annotations {
+            let range = ann.range;
+            if !range.is_empty()
+                || range.start() == TextSize::from(0)
+                || range.start() >= self.text.text_len()
+            {
+                continue;
+            }
+            if !matches!(
+                self.text.as_bytes()[range.start().to_usize() - 1],
+                b'\n' | b'\r'
+            ) {
+                continue;
+            }
+            let start = range.start();
+            let end = ceil_char_boundary(&self.text, start + TextSize::from(1));
+            ann.range = TextRange::new(start, end);
+        }
+
+        self
+    }
+}
+
+/// Finds the closest [`TextSize`] not less than the offset given for which
+/// `is_char_boundary` is `true`. Unless the offset given is greater than
+/// the length of the underlying contents, in which case, the length of the
+/// contents is returned.
+///
+/// Can be replaced with `str::ceil_char_boundary` once it's stable.
+///
+/// # Examples
+///
+/// From `std`:
+///
+/// ```
+/// use ruff_db::diagnostic::ceil_char_boundary;
+/// use ruff_text_size::{Ranged, TextLen, TextSize};
+///
+/// let source = "❤️🧡💛💚💙💜";
+/// assert_eq!(source.text_len(), TextSize::from(26));
+/// assert!(!source.is_char_boundary(13));
+///
+/// let closest = ceil_char_boundary(source, TextSize::from(13));
+/// assert_eq!(closest, TextSize::from(14));
+/// assert_eq!(&source[..closest.to_usize()], "❤️🧡💛");
+/// ```
+///
+/// Additional examples:
+///
+/// ```
+/// use ruff_db::diagnostic::ceil_char_boundary;
+/// use ruff_text_size::{Ranged, TextRange, TextSize};
+///
+/// let source = "Hello";
+///
+/// assert_eq!(
+///     ceil_char_boundary(source, TextSize::from(0)),
+///     TextSize::from(0)
+/// );
+///
+/// assert_eq!(
+///     ceil_char_boundary(source, TextSize::from(5)),
+///     TextSize::from(5)
+/// );
+///
+/// assert_eq!(
+///     ceil_char_boundary(source, TextSize::from(6)),
+///     TextSize::from(5)
+/// );
+///
+/// let source = "α";
+///
+/// assert_eq!(
+///     ceil_char_boundary(source, TextSize::from(0)),
+///     TextSize::from(0)
+/// );
+///
+/// assert_eq!(
+///     ceil_char_boundary(source, TextSize::from(1)),
+///     TextSize::from(2)
+/// );
+///
+/// assert_eq!(
+///     ceil_char_boundary(source, TextSize::from(2)),
+///     TextSize::from(2)
+/// );
+///
+/// assert_eq!(
+///     ceil_char_boundary(source, TextSize::from(3)),
+///     TextSize::from(2)
+/// );
+/// ```
+pub fn ceil_char_boundary(text: &str, offset: TextSize) -> TextSize {
+    let upper_bound = offset
+        .to_u32()
+        .saturating_add(4)
+        .min(text.text_len().to_u32());
+    (offset.to_u32()..upper_bound)
+        .map(TextSize::from)
+        .find(|offset| text.is_char_boundary(offset.to_usize()))
+        .unwrap_or_else(|| TextSize::from(upper_bound))
+}
+
 #[cfg(test)]
 mod tests {
 
-    use ruff_diagnostics::{Edit, Fix};
+    use ruff_diagnostics::{Applicability, Edit, Fix};
 
-    use crate::diagnostic::{Annotation, DiagnosticId, SecondaryCode, Severity, Span};
+    use crate::diagnostic::{
+        Annotation, DiagnosticId, IntoDiagnosticMessage, SecondaryCode, Severity, Span,
+        SubDiagnosticSeverity,
+    };
     use crate::files::system_path_to_file;
     use crate::system::{DbWithWritableSystem, SystemPath};
     use crate::tests::TestDb;
@@ -1541,7 +1844,7 @@ watermelon
 
         let mut diag = env.err().primary("animals", "3", "3", "").build();
         diag.sub(
-            env.sub_builder(Severity::Info, "this is a helpful note")
+            env.sub_builder(SubDiagnosticSeverity::Info, "this is a helpful note")
                 .build(),
         );
         insta::assert_snapshot!(
@@ -1570,15 +1873,15 @@ watermelon
 
         let mut diag = env.err().primary("animals", "3", "3", "").build();
         diag.sub(
-            env.sub_builder(Severity::Info, "this is a helpful note")
+            env.sub_builder(SubDiagnosticSeverity::Info, "this is a helpful note")
                 .build(),
         );
         diag.sub(
-            env.sub_builder(Severity::Info, "another helpful note")
+            env.sub_builder(SubDiagnosticSeverity::Info, "another helpful note")
                 .build(),
         );
         diag.sub(
-            env.sub_builder(Severity::Info, "and another helpful note")
+            env.sub_builder(SubDiagnosticSeverity::Info, "and another helpful note")
                 .build(),
         );
         insta::assert_snapshot!(
@@ -2300,6 +2603,27 @@ watermelon
             self.config = config;
         }
 
+        /// Hide diagnostic severity when rendering.
+        pub(super) fn hide_severity(&mut self, yes: bool) {
+            let mut config = std::mem::take(&mut self.config);
+            config = config.hide_severity(yes);
+            self.config = config;
+        }
+
+        /// Show fix availability when rendering.
+        pub(super) fn show_fix_status(&mut self, yes: bool) {
+            let mut config = std::mem::take(&mut self.config);
+            config = config.show_fix_status(yes);
+            self.config = config;
+        }
+
+        /// The lowest fix applicability to show when rendering.
+        pub(super) fn fix_applicability(&mut self, applicability: Applicability) {
+            let mut config = std::mem::take(&mut self.config);
+            config = config.fix_applicability(applicability);
+            self.config = config;
+        }
+
         /// Add a file with the given path and contents to this environment.
         pub(super) fn add(&mut self, path: &str, contents: &str) {
             let path = SystemPath::new(path);
@@ -2320,7 +2644,12 @@ watermelon
         /// of the corresponding line minus one. (The "minus one" is because
         /// otherwise, the span will end where the next line begins, and this
         /// confuses `ruff_annotate_snippets` as of 2025-03-13.)
-        fn span(&self, path: &str, line_offset_start: &str, line_offset_end: &str) -> Span {
+        pub(super) fn span(
+            &self,
+            path: &str,
+            line_offset_start: &str,
+            line_offset_end: &str,
+        ) -> Span {
             let span = self.path(path);
 
             let file = span.expect_ty_file();
@@ -2343,7 +2672,7 @@ watermelon
         }
 
         /// Like `span`, but only attaches a file path.
-        fn path(&self, path: &str) -> Span {
+        pub(super) fn path(&self, path: &str) -> Span {
             let file = system_path_to_file(&self.db, path).unwrap();
             Span::from(file)
         }
@@ -2363,11 +2692,11 @@ watermelon
         /// sub-diagnostic with "error" severity and canned values for
         /// its identifier and message.
         fn sub_warn(&mut self) -> SubDiagnosticBuilder<'_> {
-            self.sub_builder(Severity::Warning, "sub-diagnostic message")
+            self.sub_builder(SubDiagnosticSeverity::Warning, "sub-diagnostic message")
         }
 
         /// Returns a builder for tersely constructing diagnostics.
-        fn builder(
+        pub(super) fn builder(
             &mut self,
             identifier: &'static str,
             severity: Severity,
@@ -2384,7 +2713,11 @@ watermelon
         }
 
         /// Returns a builder for tersely constructing sub-diagnostics.
-        fn sub_builder(&mut self, severity: Severity, message: &str) -> SubDiagnosticBuilder<'_> {
+        fn sub_builder(
+            &mut self,
+            severity: SubDiagnosticSeverity,
+            message: &str,
+        ) -> SubDiagnosticBuilder<'_> {
             let subdiag = SubDiagnostic::new(severity, message);
             SubDiagnosticBuilder { env: self, subdiag }
         }
@@ -2430,7 +2763,7 @@ watermelon
         ///
         /// See the docs on `TestEnvironment::span` for the meaning of
         /// `path`, `line_offset_start` and `line_offset_end`.
-        fn primary(
+        pub(super) fn primary(
             mut self,
             path: &str,
             line_offset_start: &str,
@@ -2453,7 +2786,7 @@ watermelon
         ///
         /// See the docs on `TestEnvironment::span` for the meaning of
         /// `path`, `line_offset_start` and `line_offset_end`.
-        fn secondary(
+        pub(super) fn secondary(
             mut self,
             path: &str,
             line_offset_start: &str,
@@ -2487,6 +2820,12 @@ watermelon
             self.diag.set_noqa_offset(noqa_offset);
             self
         }
+
+        /// Adds a "help" sub-diagnostic with the given message.
+        pub(super) fn help(mut self, message: impl IntoDiagnosticMessage) -> DiagnosticBuilder<'e> {
+            self.diag.help(message);
+            self
+        }
     }
 
     /// A helper builder for tersely populating a `SubDiagnostic`.
@@ -2593,7 +2932,8 @@ def fibonacci(n):
 
         let diagnostics = vec![
             env.builder("unused-import", Severity::Error, "`os` imported but unused")
-                .primary("fib.py", "1:7", "1:9", "Remove unused import: `os`")
+                .primary("fib.py", "1:7", "1:9", "")
+                .help("Remove unused import: `os`")
                 .secondary_code("F401")
                 .fix(Fix::unsafe_edit(Edit::range_deletion(TextRange::new(
                     TextSize::from(0),
@@ -2606,12 +2946,8 @@ def fibonacci(n):
                 Severity::Error,
                 "Local variable `x` is assigned to but never used",
             )
-            .primary(
-                "fib.py",
-                "6:4",
-                "6:5",
-                "Remove assignment to unused variable `x`",
-            )
+            .primary("fib.py", "6:4", "6:5", "")
+            .help("Remove assignment to unused variable `x`")
             .secondary_code("F841")
             .fix(Fix::unsafe_edit(Edit::deletion(
                 TextSize::from(94),
@@ -2646,10 +2982,10 @@ if call(foo
         env.format(format);
 
         let diagnostics = vec![
-            env.invalid_syntax("SyntaxError: Expected one or more symbol names after import")
+            env.invalid_syntax("Expected one or more symbol names after import")
                 .primary("syntax_errors.py", "1:14", "1:15", "")
                 .build(),
-            env.invalid_syntax("SyntaxError: Expected ')', found newline")
+            env.invalid_syntax("Expected ')', found newline")
                 .primary("syntax_errors.py", "3:11", "3:12", "")
                 .build(),
         ];
@@ -2657,18 +2993,28 @@ if call(foo
         (env, diagnostics)
     }
 
-    /// Create Ruff-style diagnostics for testing the various output formats for a notebook.
-    #[allow(
-        dead_code,
-        reason = "This is currently only used for JSON but will be needed soon for other formats"
-    )]
-    pub(crate) fn create_notebook_diagnostics(
-        format: DiagnosticFormat,
-    ) -> (TestEnvironment, Vec<Diagnostic>) {
-        let mut env = TestEnvironment::new();
-        env.add(
-            "notebook.ipynb",
-            r##"
+    /// A Jupyter notebook for testing diagnostics.
+    ///
+    ///
+    /// The concatenated cells look like this:
+    ///
+    /// ```python
+    /// # cell 1
+    /// import os
+    /// # cell 2
+    /// import math
+    ///
+    /// print('hello world')
+    /// # cell 3
+    /// def foo():
+    ///     print()
+    ///     x = 1
+    /// ```
+    ///
+    /// The first diagnostic is on the unused `os` import with location cell 1, row 2, column 8
+    /// (`cell 1:2:8`). The second diagnostic is the unused `math` import at `cell 2:2:8`, and the
+    /// third diagnostic is an unfixable unused variable at `cell 3:4:5`.
+    pub(super) static NOTEBOOK: &str = r##"
         {
  "cells": [
   {
@@ -2707,13 +3053,20 @@ if call(foo
  "nbformat": 4,
  "nbformat_minor": 5
 }
-"##,
-        );
+"##;
+
+    /// Create Ruff-style diagnostics for testing the various output formats for a notebook.
+    pub(crate) fn create_notebook_diagnostics(
+        format: DiagnosticFormat,
+    ) -> (TestEnvironment, Vec<Diagnostic>) {
+        let mut env = TestEnvironment::new();
+        env.add("notebook.ipynb", NOTEBOOK);
         env.format(format);
 
         let diagnostics = vec![
             env.builder("unused-import", Severity::Error, "`os` imported but unused")
-                .primary("notebook.ipynb", "2:7", "2:9", "Remove unused import: `os`")
+                .primary("notebook.ipynb", "2:7", "2:9", "")
+                .help("Remove unused import: `os`")
                 .secondary_code("F401")
                 .fix(Fix::safe_edit(Edit::range_deletion(TextRange::new(
                     TextSize::from(9),
@@ -2726,12 +3079,8 @@ if call(foo
                 Severity::Error,
                 "`math` imported but unused",
             )
-            .primary(
-                "notebook.ipynb",
-                "4:7",
-                "4:11",
-                "Remove unused import: `math`",
-            )
+            .primary("notebook.ipynb", "4:7", "4:11", "")
+            .help("Remove unused import: `math`")
             .secondary_code("F401")
             .fix(Fix::safe_edit(Edit::range_deletion(TextRange::new(
                 TextSize::from(28),
@@ -2744,12 +3093,8 @@ if call(foo
                 Severity::Error,
                 "Local variable `x` is assigned to but never used",
             )
-            .primary(
-                "notebook.ipynb",
-                "10:4",
-                "10:5",
-                "Remove assignment to unused variable `x`",
-            )
+            .primary("notebook.ipynb", "10:4", "10:5", "")
+            .help("Remove assignment to unused variable `x`")
             .secondary_code("F841")
             .fix(Fix::unsafe_edit(Edit::range_deletion(TextRange::new(
                 TextSize::from(94),

crates/ruff_db/src/diagnostic/render/azure.rs

@@ -50,10 +50,8 @@ impl AzureRenderer<'_> {
             }
             writeln!(
                 f,
-                "{code}]{body}",
-                code = diag
-                    .secondary_code()
-                    .map_or_else(String::new, |code| format!("code={code};")),
+                "code={code};]{body}",
+                code = diag.secondary_code_or_id(),
                 body = diag.body(),
             )?;
         }

crates/ruff_db/src/diagnostic/render/concise.rs

@@ -0,0 +1,201 @@
+use crate::diagnostic::{
+    Diagnostic, DisplayDiagnosticConfig, Severity,
+    stylesheet::{DiagnosticStylesheet, fmt_styled},
+};
+
+use super::FileResolver;
+
+pub(super) struct ConciseRenderer<'a> {
+    resolver: &'a dyn FileResolver,
+    config: &'a DisplayDiagnosticConfig,
+}
+
+impl<'a> ConciseRenderer<'a> {
+    pub(super) fn new(resolver: &'a dyn FileResolver, config: &'a DisplayDiagnosticConfig) -> Self {
+        Self { resolver, config }
+    }
+
+    pub(super) fn render(
+        &self,
+        f: &mut std::fmt::Formatter,
+        diagnostics: &[Diagnostic],
+    ) -> std::fmt::Result {
+        let stylesheet = if self.config.color {
+            DiagnosticStylesheet::styled()
+        } else {
+            DiagnosticStylesheet::plain()
+        };
+
+        let sep = fmt_styled(":", stylesheet.separator);
+        for diag in diagnostics {
+            if let Some(span) = diag.primary_span() {
+                write!(
+                    f,
+                    "{path}",
+                    path = fmt_styled(
+                        span.file().relative_path(self.resolver).to_string_lossy(),
+                        stylesheet.emphasis
+                    )
+                )?;
+                if let Some(range) = span.range() {
+                    let diagnostic_source = span.file().diagnostic_source(self.resolver);
+                    let start = diagnostic_source
+                        .as_source_code()
+                        .line_column(range.start());
+
+                    if let Some(notebook_index) = self.resolver.notebook_index(span.file()) {
+                        write!(
+                            f,
+                            "{sep}cell {cell}{sep}{line}{sep}{col}",
+                            cell = notebook_index.cell(start.line).unwrap_or_default(),
+                            line = notebook_index.cell_row(start.line).unwrap_or_default(),
+                            col = start.column,
+                        )?;
+                    } else {
+                        write!(
+                            f,
+                            "{sep}{line}{sep}{col}",
+                            line = start.line,
+                            col = start.column,
+                        )?;
+                    }
+                }
+                write!(f, "{sep} ")?;
+            }
+            if self.config.hide_severity {
+                if let Some(code) = diag.secondary_code() {
+                    write!(
+                        f,
+                        "{code} ",
+                        code = fmt_styled(code, stylesheet.secondary_code)
+                    )?;
+                } else {
+                    write!(
+                        f,
+                        "{id}: ",
+                        id = fmt_styled(diag.inner.id.as_str(), stylesheet.secondary_code)
+                    )?;
+                }
+                if self.config.show_fix_status {
+                    if let Some(fix) = diag.fix() {
+                        // Do not display an indicator for inapplicable fixes
+                        if fix.applies(self.config.fix_applicability) {
+                            write!(f, "[{fix}] ", fix = fmt_styled("*", stylesheet.separator))?;
+                        }
+                    }
+                }
+            } else {
+                let (severity, severity_style) = match diag.severity() {
+                    Severity::Info => ("info", stylesheet.info),
+                    Severity::Warning => ("warning", stylesheet.warning),
+                    Severity::Error => ("error", stylesheet.error),
+                    Severity::Fatal => ("fatal", stylesheet.error),
+                };
+                write!(
+                    f,
+                    "{severity}[{id}] ",
+                    severity = fmt_styled(severity, severity_style),
+                    id = fmt_styled(diag.id(), stylesheet.emphasis)
+                )?;
+            }
+
+            writeln!(f, "{message}", message = diag.concise_message())?;
+        }
+
+        Ok(())
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use ruff_diagnostics::Applicability;
+
+    use crate::diagnostic::{
+        DiagnosticFormat,
+        render::tests::{
+            TestEnvironment, create_diagnostics, create_notebook_diagnostics,
+            create_syntax_error_diagnostics,
+        },
+    };
+
+    #[test]
+    fn output() {
+        let (env, diagnostics) = create_diagnostics(DiagnosticFormat::Concise);
+        insta::assert_snapshot!(env.render_diagnostics(&diagnostics), @r"
+        fib.py:1:8: error[unused-import] `os` imported but unused
+        fib.py:6:5: error[unused-variable] Local variable `x` is assigned to but never used
+        undef.py:1:4: error[undefined-name] Undefined name `a`
+        ");
+    }
+
+    #[test]
+    fn show_fixes() {
+        let (mut env, diagnostics) = create_diagnostics(DiagnosticFormat::Concise);
+        env.hide_severity(true);
+        env.show_fix_status(true);
+        env.fix_applicability(Applicability::DisplayOnly);
+        insta::assert_snapshot!(env.render_diagnostics(&diagnostics), @r"
+        fib.py:1:8: F401 [*] `os` imported but unused
+        fib.py:6:5: F841 [*] Local variable `x` is assigned to but never used
+        undef.py:1:4: F821 Undefined name `a`
+        ");
+    }
+
+    #[test]
+    fn show_fixes_preview() {
+        let (mut env, diagnostics) = create_diagnostics(DiagnosticFormat::Concise);
+        env.hide_severity(true);
+        env.show_fix_status(true);
+        env.fix_applicability(Applicability::DisplayOnly);
+        env.preview(true);
+        insta::assert_snapshot!(env.render_diagnostics(&diagnostics), @r"
+        fib.py:1:8: F401 [*] `os` imported but unused
+        fib.py:6:5: F841 [*] Local variable `x` is assigned to but never used
+        undef.py:1:4: F821 Undefined name `a`
+        ");
+    }
+
+    #[test]
+    fn show_fixes_syntax_errors() {
+        let (mut env, diagnostics) = create_syntax_error_diagnostics(DiagnosticFormat::Concise);
+        env.hide_severity(true);
+        env.show_fix_status(true);
+        env.fix_applicability(Applicability::DisplayOnly);
+        insta::assert_snapshot!(env.render_diagnostics(&diagnostics), @r"
+        syntax_errors.py:1:15: invalid-syntax: Expected one or more symbol names after import
+        syntax_errors.py:3:12: invalid-syntax: Expected ')', found newline
+        ");
+    }
+
+    #[test]
+    fn syntax_errors() {
+        let (env, diagnostics) = create_syntax_error_diagnostics(DiagnosticFormat::Concise);
+        insta::assert_snapshot!(env.render_diagnostics(&diagnostics), @r"
+        syntax_errors.py:1:15: error[invalid-syntax] Expected one or more symbol names after import
+        syntax_errors.py:3:12: error[invalid-syntax] Expected ')', found newline
+        ");
+    }
+
+    #[test]
+    fn notebook_output() {
+        let (env, diagnostics) = create_notebook_diagnostics(DiagnosticFormat::Concise);
+        insta::assert_snapshot!(env.render_diagnostics(&diagnostics), @r"
+        notebook.ipynb:cell 1:2:8: error[unused-import] `os` imported but unused
+        notebook.ipynb:cell 2:2:8: error[unused-import] `math` imported but unused
+        notebook.ipynb:cell 3:4:5: error[unused-variable] Local variable `x` is assigned to but never used
+        ");
+    }
+
+    #[test]
+    fn missing_file() {
+        let mut env = TestEnvironment::new();
+        env.format(DiagnosticFormat::Concise);
+
+        let diag = env.err().build();
+
+        insta::assert_snapshot!(
+            env.render(&diag),
+            @"error[test-diagnostic] main diagnostic message",
+        );
+    }
+}

crates/ruff_db/src/diagnostic/render/full.rs

@@ -0,0 +1,403 @@
+#[cfg(test)]
+mod tests {
+    use ruff_diagnostics::Applicability;
+    use ruff_text_size::TextRange;
+
+    use crate::diagnostic::{
+        Annotation, DiagnosticFormat, Severity,
+        render::tests::{
+            NOTEBOOK, TestEnvironment, create_diagnostics, create_notebook_diagnostics,
+            create_syntax_error_diagnostics,
+        },
+    };
+
+    #[test]
+    fn output() {
+        let (env, diagnostics) = create_diagnostics(DiagnosticFormat::Full);
+        insta::assert_snapshot!(env.render_diagnostics(&diagnostics), @r#"
+        error[unused-import]: `os` imported but unused
+         --> fib.py:1:8
+          |
+        1 | import os
+          |        ^^
+          |
+        help: Remove unused import: `os`
+
+        error[unused-variable]: Local variable `x` is assigned to but never used
+         --> fib.py:6:5
+          |
+        4 | def fibonacci(n):
+        5 |     """Compute the nth number in the Fibonacci sequence."""
+        6 |     x = 1
+          |     ^
+        7 |     if n == 0:
+        8 |         return 0
+          |
+        help: Remove assignment to unused variable `x`
+
+        error[undefined-name]: Undefined name `a`
+         --> undef.py:1:4
+          |
+        1 | if a == 1: pass
+          |    ^
+          |
+        "#);
+    }
+
+    #[test]
+    fn syntax_errors() {
+        let (env, diagnostics) = create_syntax_error_diagnostics(DiagnosticFormat::Full);
+        insta::assert_snapshot!(env.render_diagnostics(&diagnostics), @r"
+        error[invalid-syntax]: Expected one or more symbol names after import
+         --> syntax_errors.py:1:15
+          |
+        1 | from os import
+          |               ^
+        2 |
+        3 | if call(foo
+          |
+
+        error[invalid-syntax]: Expected ')', found newline
+         --> syntax_errors.py:3:12
+          |
+        1 | from os import
+        2 |
+        3 | if call(foo
+          |            ^
+        4 |     def bar():
+        5 |         pass
+          |
+        ");
+    }
+
+    #[test]
+    fn hide_severity_output() {
+        let (mut env, diagnostics) = create_diagnostics(DiagnosticFormat::Full);
+        env.hide_severity(true);
+        env.fix_applicability(Applicability::DisplayOnly);
+
+        insta::assert_snapshot!(env.render_diagnostics(&diagnostics), @r#"
+        F401 [*] `os` imported but unused
+         --> fib.py:1:8
+          |
+        1 | import os
+          |        ^^
+          |
+        help: Remove unused import: `os`
+
+        F841 [*] Local variable `x` is assigned to but never used
+         --> fib.py:6:5
+          |
+        4 | def fibonacci(n):
+        5 |     """Compute the nth number in the Fibonacci sequence."""
+        6 |     x = 1
+          |     ^
+        7 |     if n == 0:
+        8 |         return 0
+          |
+        help: Remove assignment to unused variable `x`
+
+        F821 Undefined name `a`
+         --> undef.py:1:4
+          |
+        1 | if a == 1: pass
+          |    ^
+          |
+        "#);
+    }
+
+    #[test]
+    fn hide_severity_syntax_errors() {
+        let (mut env, diagnostics) = create_syntax_error_diagnostics(DiagnosticFormat::Full);
+        env.hide_severity(true);
+
+        insta::assert_snapshot!(env.render_diagnostics(&diagnostics), @r"
+        invalid-syntax: Expected one or more symbol names after import
+         --> syntax_errors.py:1:15
+          |
+        1 | from os import
+          |               ^
+        2 |
+        3 | if call(foo
+          |
+
+        invalid-syntax: Expected ')', found newline
+         --> syntax_errors.py:3:12
+          |
+        1 | from os import
+        2 |
+        3 | if call(foo
+          |            ^
+        4 |     def bar():
+        5 |         pass
+          |
+        ");
+    }
+
+    /// Check that the new `full` rendering code in `ruff_db` handles cases fixed by commit c9b99e4.
+    ///
+    /// For example, without the fix, we get diagnostics like this:
+    ///
+    /// ```
+    /// error[no-indented-block]: Expected an indented block
+    ///  --> example.py:3:1
+    ///   |
+    /// 2 | if False:
+    ///   |          ^
+    /// 3 | print()
+    ///   |
+    ///  ```
+    ///
+    /// where the caret points to the end of the previous line instead of the start of the next.
+    #[test]
+    fn empty_span_after_line_terminator() {
+        let mut env = TestEnvironment::new();
+        env.add(
+            "example.py",
+            r#"
+if False:
+print()
+"#,
+        );
+        env.format(DiagnosticFormat::Full);
+
+        let diagnostic = env
+            .builder(
+                "no-indented-block",
+                Severity::Error,
+                "Expected an indented block",
+            )
+            .primary("example.py", "3:0", "3:0", "")
+            .build();
+
+        insta::assert_snapshot!(env.render(&diagnostic), @r"
+        error[no-indented-block]: Expected an indented block
+         --> example.py:3:1
+          |
+        2 | if False:
+        3 | print()
+          | ^
+          |
+        ");
+    }
+
+    /// Check that the new `full` rendering code in `ruff_db` handles cases fixed by commit 2922490.
+    ///
+    /// For example, without the fix, we get diagnostics like this:
+    ///
+    /// ```
+    /// error[invalid-character-sub]: Invalid unescaped character SUB, use "\x1A" instead
+    ///  --> example.py:1:25
+    ///   |
+    /// 1 | nested_fstrings = f'␈{f'{f'␛'}'}'
+    ///   |                       ^
+    ///   |
+    ///  ```
+    ///
+    /// where the caret points to the `f` in the f-string instead of the start of the invalid
+    /// character (`^Z`).
+    #[test]
+    fn unprintable_characters() {
+        let mut env = TestEnvironment::new();
+        env.add("example.py", "nested_fstrings = f'{f'{f''}'}'");
+        env.format(DiagnosticFormat::Full);
+
+        let diagnostic = env
+            .builder(
+                "invalid-character-sub",
+                Severity::Error,
+                r#"Invalid unescaped character SUB, use "\x1A" instead"#,
+            )
+            .primary("example.py", "1:24", "1:24", "")
+            .build();
+
+        insta::assert_snapshot!(env.render(&diagnostic), @r#"
+        error[invalid-character-sub]: Invalid unescaped character SUB, use "\x1A" instead
+         --> example.py:1:25
+          |
+        1 | nested_fstrings = f'␈{f'{f'␛'}'}'
+          |                         ^
+          |
+        "#);
+    }
+
+    #[test]
+    fn multiple_unprintable_characters() -> std::io::Result<()> {
+        let mut env = TestEnvironment::new();
+        env.add("example.py", "");
+        env.format(DiagnosticFormat::Full);
+
+        let diagnostic = env
+            .builder(
+                "invalid-character-sub",
+                Severity::Error,
+                r#"Invalid unescaped character SUB, use "\x1A" instead"#,
+            )
+            .primary("example.py", "1:1", "1:1", "")
+            .build();
+
+        insta::assert_snapshot!(env.render(&diagnostic), @r#"
+        error[invalid-character-sub]: Invalid unescaped character SUB, use "\x1A" instead
+         --> example.py:1:2
+          |
+        1 | ␈␛
+          |  ^
+          |
+        "#);
+
+        Ok(())
+    }
+
+    /// Ensure that the header column matches the column in the user's input, even if we've replaced
+    /// tabs with spaces for rendering purposes.
+    #[test]
+    fn tab_replacement() {
+        let mut env = TestEnvironment::new();
+        env.add("example.py", "def foo():\n\treturn 1");
+        env.format(DiagnosticFormat::Full);
+
+        let diagnostic = env.err().primary("example.py", "2:1", "2:9", "").build();
+
+        insta::assert_snapshot!(env.render(&diagnostic), @r"
+        error[test-diagnostic]: main diagnostic message
+         --> example.py:2:2
+          |
+        1 | def foo():
+        2 |     return 1
+          |     ^^^^^^^^
+          |
+        ");
+    }
+
+    /// For file-level diagnostics, we expect to see the header line with the diagnostic information
+    /// and the `-->` line with the file information but no lines of source code.
+    #[test]
+    fn file_level() {
+        let mut env = TestEnvironment::new();
+        env.add("example.py", "");
+        env.format(DiagnosticFormat::Full);
+
+        let mut diagnostic = env.err().build();
+        let span = env.path("example.py").with_range(TextRange::default());
+        let mut annotation = Annotation::primary(span);
+        annotation.set_file_level(true);
+        diagnostic.annotate(annotation);
+
+        insta::assert_snapshot!(env.render(&diagnostic), @r"
+        error[test-diagnostic]: main diagnostic message
+        --> example.py:1:1
+        ");
+    }
+
+    /// Check that ranges in notebooks are remapped relative to the cells.
+    #[test]
+    fn notebook_output() {
+        let (env, diagnostics) = create_notebook_diagnostics(DiagnosticFormat::Full);
+        insta::assert_snapshot!(env.render_diagnostics(&diagnostics), @r"
+        error[unused-import][*]: `os` imported but unused
+         --> notebook.ipynb:cell 1:2:8
+          |
+        1 | # cell 1
+        2 | import os
+          |        ^^
+          |
+        help: Remove unused import: `os`
+
+        error[unused-import][*]: `math` imported but unused
+         --> notebook.ipynb:cell 2:2:8
+          |
+        1 | # cell 2
+        2 | import math
+          |        ^^^^
+        3 |
+        4 | print('hello world')
+          |
+        help: Remove unused import: `math`
+
+        error[unused-variable]: Local variable `x` is assigned to but never used
+         --> notebook.ipynb:cell 3:4:5
+          |
+        2 | def foo():
+        3 |     print()
+        4 |     x = 1
+          |     ^
+          |
+        help: Remove assignment to unused variable `x`
+        ");
+    }
+
+    /// Check notebook handling for multiple annotations in a single diagnostic that span cells.
+    #[test]
+    fn notebook_output_multiple_annotations() {
+        let mut env = TestEnvironment::new();
+        env.add("notebook.ipynb", NOTEBOOK);
+
+        let diagnostics = vec![
+            // adjacent context windows
+            env.builder("unused-import", Severity::Error, "`os` imported but unused")
+                .primary("notebook.ipynb", "2:7", "2:9", "")
+                .secondary("notebook.ipynb", "4:7", "4:11", "second cell")
+                .help("Remove unused import: `os`")
+                .build(),
+            // non-adjacent context windows
+            env.builder("unused-import", Severity::Error, "`os` imported but unused")
+                .primary("notebook.ipynb", "2:7", "2:9", "")
+                .secondary("notebook.ipynb", "10:4", "10:5", "second cell")
+                .help("Remove unused import: `os`")
+                .build(),
+            // adjacent context windows in the same cell
+            env.err()
+                .primary("notebook.ipynb", "4:7", "4:11", "second cell")
+                .secondary("notebook.ipynb", "6:0", "6:5", "print statement")
+                .help("Remove `print` statement")
+                .build(),
+        ];
+
+        insta::assert_snapshot!(env.render_diagnostics(&diagnostics), @r"
+        error[unused-import]: `os` imported but unused
+         --> notebook.ipynb:cell 1:2:8
+          |
+        1 | # cell 1
+        2 | import os
+          |        ^^
+          |
+         ::: notebook.ipynb:cell 2:2:8
+          |
+        1 | # cell 2
+        2 | import math
+          |        ---- second cell
+        3 |
+        4 | print('hello world')
+          |
+        help: Remove unused import: `os`
+
+        error[unused-import]: `os` imported but unused
+         --> notebook.ipynb:cell 1:2:8
+          |
+        1 | # cell 1
+        2 | import os
+          |        ^^
+          |
+         ::: notebook.ipynb:cell 3:4:5
+          |
+        2 | def foo():
+        3 |     print()
+        4 |     x = 1
+          |     - second cell
+          |
+        help: Remove unused import: `os`
+
+        error[test-diagnostic]: main diagnostic message
+         --> notebook.ipynb:cell 2:2:8
+          |
+        1 | # cell 2
+        2 | import math
+          |        ^^^^ second cell
+        3 |
+        4 | print('hello world')
+          | ----- print statement
+          |
+        help: Remove `print` statement
+        ");
+    }
+}

crates/ruff_db/src/diagnostic/render/json.rs

@@ -6,7 +6,7 @@ use ruff_notebook::NotebookIndex;
 use ruff_source_file::{LineColumn, OneIndexed};
 use ruff_text_size::Ranged;
 
-use crate::diagnostic::{Diagnostic, DiagnosticSource, DisplayDiagnosticConfig, SecondaryCode};
+use crate::diagnostic::{Diagnostic, DiagnosticSource, DisplayDiagnosticConfig};
 
 use super::FileResolver;
 
@@ -87,7 +87,7 @@ pub(super) fn diagnostic_to_json<'a>(
 
     let fix = diagnostic.fix().map(|fix| JsonFix {
         applicability: fix.applicability(),
-        message: diagnostic.suggestion(),
+        message: diagnostic.first_help_text(),
         edits: ExpandedEdits {
             edits: fix.edits(),
             notebook_index,
@@ -99,7 +99,7 @@ pub(super) fn diagnostic_to_json<'a>(
     // In preview, the locations and filename can be optional.
     if config.preview {
         JsonDiagnostic {
-            code: diagnostic.secondary_code(),
+            code: diagnostic.secondary_code_or_id(),
             url: diagnostic.to_ruff_url(),
             message: diagnostic.body(),
             fix,
@@ -111,7 +111,7 @@ pub(super) fn diagnostic_to_json<'a>(
         }
     } else {
         JsonDiagnostic {
-            code: diagnostic.secondary_code(),
+            code: diagnostic.secondary_code_or_id(),
             url: diagnostic.to_ruff_url(),
             message: diagnostic.body(),
             fix,
@@ -221,7 +221,7 @@ impl Serialize for ExpandedEdits<'_> {
 #[derive(Serialize)]
 pub(crate) struct JsonDiagnostic<'a> {
     cell: Option<OneIndexed>,
-    code: Option<&'a SecondaryCode>,
+    code: &'a str,
     end_location: Option<JsonLocation>,
     filename: Option<&'a str>,
     fix: Option<JsonFix<'a>>,
@@ -302,7 +302,7 @@ mod tests {
         [
           {
             "cell": null,
-            "code": null,
+            "code": "test-diagnostic",
             "end_location": {
               "column": 1,
               "row": 1
@@ -336,7 +336,7 @@ mod tests {
         [
           {
             "cell": null,
-            "code": null,
+            "code": "test-diagnostic",
             "end_location": null,
             "filename": null,
             "fix": null,

crates/ruff_db/src/diagnostic/render/junit.rs

@@ -0,0 +1,195 @@
+use std::{collections::BTreeMap, ops::Deref, path::Path};
+
+use quick_junit::{NonSuccessKind, Report, TestCase, TestCaseStatus, TestSuite, XmlString};
+
+use ruff_source_file::LineColumn;
+
+use crate::diagnostic::{Diagnostic, SecondaryCode, render::FileResolver};
+
+/// A renderer for diagnostics in the [JUnit] format.
+///
+/// See [`junit.xsd`] for the specification in the JUnit repository and an annotated [version]
+/// linked from the [`quick_junit`] docs.
+///
+/// [JUnit]: https://junit.org/
+/// [`junit.xsd`]: https://github.com/junit-team/junit-framework/blob/2870b7d8fd5bf7c1efe489d3991d3ed3900e82bb/platform-tests/src/test/resources/jenkins-junit.xsd
+/// [version]: https://llg.cubic.org/docs/junit/
+/// [`quick_junit`]: https://docs.rs/quick-junit/latest/quick_junit/
+pub struct JunitRenderer<'a> {
+    resolver: &'a dyn FileResolver,
+}
+
+impl<'a> JunitRenderer<'a> {
+    pub fn new(resolver: &'a dyn FileResolver) -> Self {
+        Self { resolver }
+    }
+
+    pub(super) fn render(
+        &self,
+        f: &mut std::fmt::Formatter,
+        diagnostics: &[Diagnostic],
+    ) -> std::fmt::Result {
+        let mut report = Report::new("ruff");
+
+        if diagnostics.is_empty() {
+            let mut test_suite = TestSuite::new("ruff");
+            test_suite
+                .extra
+                .insert(XmlString::new("package"), XmlString::new("org.ruff"));
+            let mut case = TestCase::new("No errors found", TestCaseStatus::success());
+            case.set_classname("ruff");
+            test_suite.add_test_case(case);
+            report.add_test_suite(test_suite);
+        } else {
+            for (filename, diagnostics) in group_diagnostics_by_filename(diagnostics, self.resolver)
+            {
+                let mut test_suite = TestSuite::new(filename);
+                test_suite
+                    .extra
+                    .insert(XmlString::new("package"), XmlString::new("org.ruff"));
+
+                let classname = Path::new(filename).with_extension("");
+
+                for diagnostic in diagnostics {
+                    let DiagnosticWithLocation {
+                        diagnostic,
+                        start_location: location,
+                    } = diagnostic;
+                    let mut status = TestCaseStatus::non_success(NonSuccessKind::Failure);
+                    status.set_message(diagnostic.body());
+
+                    if let Some(location) = location {
+                        status.set_description(format!(
+                            "line {row}, col {col}, {body}",
+                            row = location.line,
+                            col = location.column,
+                            body = diagnostic.body()
+                        ));
+                    } else {
+                        status.set_description(diagnostic.body());
+                    }
+
+                    let code = diagnostic
+                        .secondary_code()
+                        .map_or_else(|| diagnostic.name(), SecondaryCode::as_str);
+                    let mut case = TestCase::new(format!("org.ruff.{code}"), status);
+                    case.set_classname(classname.to_str().unwrap());
+
+                    if let Some(location) = location {
+                        case.extra.insert(
+                            XmlString::new("line"),
+                            XmlString::new(location.line.to_string()),
+                        );
+                        case.extra.insert(
+                            XmlString::new("column"),
+                            XmlString::new(location.column.to_string()),
+                        );
+                    }
+
+                    test_suite.add_test_case(case);
+                }
+                report.add_test_suite(test_suite);
+            }
+        }
+
+        let adapter = FmtAdapter { fmt: f };
+        report.serialize(adapter).map_err(|_| std::fmt::Error)
+    }
+}
+
+// TODO(brent) this and `group_diagnostics_by_filename` are also used by the `grouped` output
+// format. I think they'd make more sense in that file, but I started here first. I'll move them to
+// that module when adding the `grouped` output format.
+struct DiagnosticWithLocation<'a> {
+    diagnostic: &'a Diagnostic,
+    start_location: Option<LineColumn>,
+}
+
+impl Deref for DiagnosticWithLocation<'_> {
+    type Target = Diagnostic;
+
+    fn deref(&self) -> &Self::Target {
+        self.diagnostic
+    }
+}
+
+fn group_diagnostics_by_filename<'a>(
+    diagnostics: &'a [Diagnostic],
+    resolver: &'a dyn FileResolver,
+) -> BTreeMap<&'a str, Vec<DiagnosticWithLocation<'a>>> {
+    let mut grouped_diagnostics = BTreeMap::default();
+    for diagnostic in diagnostics {
+        let (filename, start_location) = diagnostic
+            .primary_span_ref()
+            .map(|span| {
+                let file = span.file();
+                let start_location =
+                    span.range()
+                        .filter(|_| !resolver.is_notebook(file))
+                        .map(|range| {
+                            file.diagnostic_source(resolver)
+                                .as_source_code()
+                                .line_column(range.start())
+                        });
+
+                (span.file().path(resolver), start_location)
+            })
+            .unwrap_or_default();
+
+        grouped_diagnostics
+            .entry(filename)
+            .or_insert_with(Vec::new)
+            .push(DiagnosticWithLocation {
+                diagnostic,
+                start_location,
+            });
+    }
+    grouped_diagnostics
+}
+
+struct FmtAdapter<'a> {
+    fmt: &'a mut dyn std::fmt::Write,
+}
+
+impl std::io::Write for FmtAdapter<'_> {
+    fn write(&mut self, buf: &[u8]) -> std::io::Result<usize> {
+        self.fmt
+            .write_str(std::str::from_utf8(buf).map_err(|_| {
+                std::io::Error::new(
+                    std::io::ErrorKind::InvalidData,
+                    "Invalid UTF-8 in JUnit report",
+                )
+            })?)
+            .map_err(std::io::Error::other)?;
+
+        Ok(buf.len())
+    }
+
+    fn flush(&mut self) -> std::io::Result<()> {
+        Ok(())
+    }
+
+    fn write_fmt(&mut self, args: std::fmt::Arguments<'_>) -> std::io::Result<()> {
+        self.fmt.write_fmt(args).map_err(std::io::Error::other)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use crate::diagnostic::{
+        DiagnosticFormat,
+        render::tests::{create_diagnostics, create_syntax_error_diagnostics},
+    };
+
+    #[test]
+    fn output() {
+        let (env, diagnostics) = create_diagnostics(DiagnosticFormat::Junit);
+        insta::assert_snapshot!(env.render_diagnostics(&diagnostics));
+    }
+
+    #[test]
+    fn syntax_errors() {
+        let (env, diagnostics) = create_syntax_error_diagnostics(DiagnosticFormat::Junit);
+        insta::assert_snapshot!(env.render_diagnostics(&diagnostics));
+    }
+}

crates/ruff_db/src/diagnostic/render/snapshots/ruff_db__diagnostic__render__azure__tests__syntax_errors.snap

@@ -2,5 +2,5 @@
 source: crates/ruff_db/src/diagnostic/render/azure.rs
 expression: env.render_diagnostics(&diagnostics)
 ---
-##vso[task.logissue type=error;sourcepath=syntax_errors.py;linenumber=1;columnnumber=15;]SyntaxError: Expected one or more symbol names after import
-##vso[task.logissue type=error;sourcepath=syntax_errors.py;linenumber=3;columnnumber=12;]SyntaxError: Expected ')', found newline
+##vso[task.logissue type=error;sourcepath=syntax_errors.py;linenumber=1;columnnumber=15;code=invalid-syntax;]Expected one or more symbol names after import
+##vso[task.logissue type=error;sourcepath=syntax_errors.py;linenumber=3;columnnumber=12;code=invalid-syntax;]Expected ')', found newline

crates/ruff_db/src/diagnostic/render/snapshots/ruff_db__diagnostic__render__json__tests__syntax_errors.snap

@@ -5,7 +5,7 @@ expression: env.render_diagnostics(&diagnostics)
 [
   {
     "cell": null,
-    "code": null,
+    "code": "invalid-syntax",
     "end_location": {
       "column": 1,
       "row": 2
@@ -16,13 +16,13 @@ expression: env.render_diagnostics(&diagnostics)
       "column": 15,
       "row": 1
     },
-    "message": "SyntaxError: Expected one or more symbol names after import",
+    "message": "Expected one or more symbol names after import",
     "noqa_row": null,
     "url": null
   },
   {
     "cell": null,
-    "code": null,
+    "code": "invalid-syntax",
     "end_location": {
       "column": 1,
       "row": 4
@@ -33,7 +33,7 @@ expression: env.render_diagnostics(&diagnostics)
       "column": 12,
       "row": 3
     },
-    "message": "SyntaxError: Expected ')', found newline",
+    "message": "Expected ')', found newline",
     "noqa_row": null,
     "url": null
   }

crates/ruff_db/src/diagnostic/render/snapshots/ruff_db__diagnostic__render__json_lines__tests__syntax_errors.snap

@@ -2,5 +2,5 @@
 source: crates/ruff_db/src/diagnostic/render/json_lines.rs
 expression: env.render_diagnostics(&diagnostics)
 ---
-{"cell":null,"code":null,"end_location":{"column":1,"row":2},"filename":"syntax_errors.py","fix":null,"location":{"column":15,"row":1},"message":"SyntaxError: Expected one or more symbol names after import","noqa_row":null,"url":null}
-{"cell":null,"code":null,"end_location":{"column":1,"row":4},"filename":"syntax_errors.py","fix":null,"location":{"column":12,"row":3},"message":"SyntaxError: Expected ')', found newline","noqa_row":null,"url":null}
+{"cell":null,"code":"invalid-syntax","end_location":{"column":1,"row":2},"filename":"syntax_errors.py","fix":null,"location":{"column":15,"row":1},"message":"Expected one or more symbol names after import","noqa_row":null,"url":null}
+{"cell":null,"code":"invalid-syntax","end_location":{"column":1,"row":4},"filename":"syntax_errors.py","fix":null,"location":{"column":12,"row":3},"message":"Expected ')', found newline","noqa_row":null,"url":null}

crates/ruff_db/src/diagnostic/render/snapshots/ruff_db__diagnostic__render__junit__tests__output.snap

@@ -1,7 +1,6 @@
 ---
-source: crates/ruff_linter/src/message/junit.rs
-expression: content
-snapshot_kind: text
+source: crates/ruff_db/src/diagnostic/render/junit.rs
+expression: env.render_diagnostics(&diagnostics)
 ---
 <?xml version="1.0" encoding="UTF-8"?>
 <testsuites name="ruff" tests="3" failures="3" errors="0">

crates/ruff_db/src/diagnostic/render/snapshots/ruff_db__diagnostic__render__junit__tests__syntax_errors.snap

@@ -0,0 +1,15 @@
+---
+source: crates/ruff_db/src/diagnostic/render/junit.rs
+expression: env.render_diagnostics(&diagnostics)
+---
+<?xml version="1.0" encoding="UTF-8"?>
+<testsuites name="ruff" tests="2" failures="2" errors="0">
+    <testsuite name="syntax_errors.py" tests="2" disabled="0" errors="0" failures="2" package="org.ruff">
+        <testcase name="org.ruff.invalid-syntax" classname="syntax_errors" line="1" column="15">
+            <failure message="Expected one or more symbol names after import">line 1, col 15, Expected one or more symbol names after import</failure>
+        </testcase>
+        <testcase name="org.ruff.invalid-syntax" classname="syntax_errors" line="3" column="12">
+            <failure message="Expected &apos;)&apos;, found newline">line 3, col 12, Expected &apos;)&apos;, found newline</failure>
+        </testcase>
+    </testsuite>
+</testsuites>

crates/ruff_db/src/diagnostic/render/snapshots/ruff_db__diagnostic__render__pylint__tests__syntax_errors.snap

@@ -2,5 +2,5 @@
 source: crates/ruff_db/src/diagnostic/render/pylint.rs
 expression: env.render_diagnostics(&diagnostics)
 ---
-syntax_errors.py:1: [invalid-syntax] SyntaxError: Expected one or more symbol names after import
-syntax_errors.py:3: [invalid-syntax] SyntaxError: Expected ')', found newline
+syntax_errors.py:1: [invalid-syntax] Expected one or more symbol names after import
+syntax_errors.py:3: [invalid-syntax] Expected ')', found newline

crates/ruff_db/src/diagnostic/render/snapshots/ruff_db__diagnostic__render__rdjson__tests__syntax_errors.snap

@@ -21,7 +21,7 @@ expression: env.render_diagnostics(&diagnostics)
           }
         }
       },
-      "message": "SyntaxError: Expected one or more symbol names after import"
+      "message": "Expected one or more symbol names after import"
     },
     {
       "code": {
@@ -40,7 +40,7 @@ expression: env.render_diagnostics(&diagnostics)
           }
         }
       },
-      "message": "SyntaxError: Expected ')', found newline"
+      "message": "Expected ')', found newline"
     }
   ],
   "severity": "WARNING",

crates/ruff_db/src/diagnostic/stylesheet.rs

@@ -41,6 +41,8 @@ pub struct DiagnosticStylesheet {
     pub(crate) line_no: Style,
     pub(crate) emphasis: Style,
     pub(crate) none: Style,
+    pub(crate) separator: Style,
+    pub(crate) secondary_code: Style,
 }
 
 impl Default for DiagnosticStylesheet {
@@ -62,6 +64,8 @@ impl DiagnosticStylesheet {
             line_no: bright_blue.effects(Effects::BOLD),
             emphasis: Style::new().effects(Effects::BOLD),
             none: Style::new(),
+            separator: AnsiColor::Cyan.on_default(),
+            secondary_code: AnsiColor::Red.on_default().effects(Effects::BOLD),
         }
     }
 
@@ -75,6 +79,8 @@ impl DiagnosticStylesheet {
             line_no: Style::new(),
             emphasis: Style::new(),
             none: Style::new(),
+            separator: Style::new(),
+            secondary_code: Style::new(),
         }
     }
 }

crates/ruff_db/src/files.rs

@@ -1,7 +1,6 @@
 use std::fmt;
 use std::sync::Arc;
 
-use countme::Count;
 use dashmap::mapref::entry::Entry;
 pub use file_root::{FileRoot, FileRootKind};
 pub use path::FilePath;
@@ -232,7 +231,7 @@ impl Files {
         let roots = inner.roots.read().unwrap();
 
         for root in roots.all() {
-            if root.path(db).starts_with(&path) {
+            if path.starts_with(root.path(db)) {
                 root.set_revision(db).to(FileRevision::now());
             }
         }
@@ -312,11 +311,6 @@ pub struct File {
     /// the file has been deleted is to change the status to `Deleted`.
     #[default]
     status: FileStatus,
-
-    /// Counter that counts the number of created file instances and active file instances.
-    /// Only enabled in debug builds.
-    #[default]
-    count: Count<File>,
 }
 
 // The Salsa heap is tracked separately.
@@ -375,12 +369,25 @@ impl File {
     }
 
     /// Refreshes the file metadata by querying the file system if needed.
+    ///
+    /// This also "touches" the file root associated with the given path.
+    /// This means that any Salsa queries that depend on the corresponding
+    /// root's revision will become invalidated.
     pub fn sync_path(db: &mut dyn Db, path: &SystemPath) {
         let absolute = SystemPath::absolute(path, db.system().current_directory());
         Files::touch_root(db, &absolute);
         Self::sync_system_path(db, &absolute, None);
     }
 
+    /// Refreshes *only* the file metadata by querying the file system if needed.
+    ///
+    /// This specifically does not touch any file root associated with the
+    /// given file path.
+    pub fn sync_path_only(db: &mut dyn Db, path: &SystemPath) {
+        let absolute = SystemPath::absolute(path, db.system().current_directory());
+        Self::sync_system_path(db, &absolute, None);
+    }
+
     /// Increments the revision for the virtual file at `path`.
     pub fn sync_virtual_path(db: &mut dyn Db, path: &SystemVirtualPath) {
         if let Some(virtual_file) = db.files().try_virtual_file(path) {
@@ -486,7 +493,7 @@ impl fmt::Debug for File {
 ///
 /// This is a wrapper around a [`File`] that provides additional methods to interact with a virtual
 /// file.
-#[derive(Copy, Clone)]
+#[derive(Copy, Clone, Debug)]
 pub struct VirtualFile(File);
 
 impl VirtualFile {

crates/ruff_db/src/files/file_root.rs

@@ -23,7 +23,7 @@ pub struct FileRoot {
     pub path: SystemPathBuf,
 
     /// The kind of the root at the time of its creation.
-    kind_at_time_of_creation: FileRootKind,
+    pub kind_at_time_of_creation: FileRootKind,
 
     /// A revision that changes when the contents of the source root change.
     ///

crates/ruff_db/src/parsed.rs

@@ -21,7 +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, heap_size=get_size2::GetSize::get_heap_size)]
+#[salsa::tracked(returns(ref), no_eq, heap_size=ruff_memory_usage::heap_size)]
 pub fn parsed_module(db: &dyn Db, file: File) -> ParsedModule {
     let _span = tracing::trace_span!("parsed_module", ?file).entered();
 

crates/ruff_db/src/source.rs

@@ -1,8 +1,6 @@
 use std::ops::Deref;
 use std::sync::Arc;
 
-use countme::Count;
-
 use ruff_notebook::Notebook;
 use ruff_python_ast::PySourceType;
 use ruff_source_file::LineIndex;
@@ -11,7 +9,7 @@ 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(heap_size=get_size2::GetSize::get_heap_size)]
+#[salsa::tracked(heap_size=ruff_memory_usage::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();
@@ -38,11 +36,7 @@ pub fn source_text(db: &dyn Db, file: File) -> SourceText {
     };
 
     SourceText {
-        inner: Arc::new(SourceTextInner {
-            kind,
-            read_error,
-            count: Count::new(),
-        }),
+        inner: Arc::new(SourceTextInner { kind, read_error }),
     }
 }
 
@@ -75,21 +69,21 @@ impl SourceText {
     pub fn as_str(&self) -> &str {
         match &self.inner.kind {
             SourceTextKind::Text(source) => source,
-            SourceTextKind::Notebook(notebook) => notebook.source_code(),
+            SourceTextKind::Notebook { notebook } => notebook.source_code(),
         }
     }
 
     /// Returns the underlying notebook if this is a notebook file.
     pub fn as_notebook(&self) -> Option<&Notebook> {
         match &self.inner.kind {
-            SourceTextKind::Notebook(notebook) => Some(notebook),
+            SourceTextKind::Notebook { notebook } => Some(notebook),
             SourceTextKind::Text(_) => None,
         }
     }
 
     /// Returns `true` if this is a notebook source file.
     pub fn is_notebook(&self) -> bool {
-        matches!(&self.inner.kind, SourceTextKind::Notebook(_))
+        matches!(&self.inner.kind, SourceTextKind::Notebook { .. })
     }
 
     /// Returns `true` if there was an error when reading the content of the file.
@@ -114,7 +108,7 @@ impl std::fmt::Debug for SourceText {
             SourceTextKind::Text(text) => {
                 dbg.field(text);
             }
-            SourceTextKind::Notebook(notebook) => {
+            SourceTextKind::Notebook { notebook } => {
                 dbg.field(notebook);
             }
         }
@@ -125,29 +119,19 @@ impl std::fmt::Debug for SourceText {
 
 #[derive(Eq, PartialEq, get_size2::GetSize)]
 struct SourceTextInner {
-    #[get_size(ignore)]
-    count: Count<SourceText>,
     kind: SourceTextKind,
     read_error: Option<SourceTextError>,
 }
 
-#[derive(Eq, PartialEq)]
+#[derive(Eq, PartialEq, get_size2::GetSize)]
 enum SourceTextKind {
     Text(String),
-    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,
-        }
-    }
+    Notebook {
+        // Jupyter notebooks are not very relevant for memory profiling, and contain
+        // arbitrary JSON values that do not implement the `GetSize` trait.
+        #[get_size(ignore)]
+        notebook: Box<Notebook>,
+    },
 }
 
 impl From<String> for SourceTextKind {
@@ -158,7 +142,9 @@ impl From<String> for SourceTextKind {
 
 impl From<Notebook> for SourceTextKind {
     fn from(notebook: Notebook) -> Self {
-        SourceTextKind::Notebook(Box::new(notebook))
+        SourceTextKind::Notebook {
+            notebook: Box::new(notebook),
+        }
     }
 }
 
@@ -171,7 +157,7 @@ pub enum SourceTextError {
 }
 
 /// Computes the [`LineIndex`] for `file`.
-#[salsa::tracked(heap_size=get_size2::GetSize::get_heap_size)]
+#[salsa::tracked(heap_size=ruff_memory_usage::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/path.rs

@@ -236,7 +236,7 @@ impl SystemPath {
     ///
     /// [`CurDir`]: camino::Utf8Component::CurDir
     #[inline]
-    pub fn components(&self) -> camino::Utf8Components {
+    pub fn components(&self) -> camino::Utf8Components<'_> {
         self.0.components()
     }
 

crates/ruff_db/src/vendored.rs

@@ -195,7 +195,7 @@ impl VendoredFileSystem {
     ///
     /// ## Panics:
     /// If the current thread already holds the lock.
-    fn lock_archive(&self) -> LockedZipArchive {
+    fn lock_archive(&self) -> LockedZipArchive<'_> {
         self.inner.lock().unwrap()
     }
 }
@@ -360,7 +360,7 @@ impl VendoredZipArchive {
         Ok(Self(ZipArchive::new(io::Cursor::new(data))?))
     }
 
-    fn lookup_path(&mut self, path: &NormalizedVendoredPath) -> Result<ZipFile> {
+    fn lookup_path(&mut self, path: &NormalizedVendoredPath) -> Result<ZipFile<'_>> {
         Ok(self.0.by_name(path.as_str())?)
     }
 

crates/ruff_db/src/vendored/path.rs

@@ -37,7 +37,7 @@ impl VendoredPath {
         self.0.as_std_path()
     }
 
-    pub fn components(&self) -> Utf8Components {
+    pub fn components(&self) -> Utf8Components<'_> {
         self.0.components()
     }
 

crates/ruff_dev/src/format_dev.rs

@@ -348,7 +348,7 @@ fn format_dev_multi_project(
         debug!(parent: None, "Starting {}", project_path.display());
 
         match format_dev_project(
-            &[project_path.clone()],
+            std::slice::from_ref(&project_path),
             args.stability_check,
             args.write,
             args.preview,
@@ -628,7 +628,7 @@ struct CheckRepoResult {
 }
 
 impl CheckRepoResult {
-    fn display(&self, format: Format) -> DisplayCheckRepoResult {
+    fn display(&self, format: Format) -> DisplayCheckRepoResult<'_> {
         DisplayCheckRepoResult {
             result: self,
             format,
@@ -665,7 +665,7 @@ struct Diagnostic {
 }
 
 impl Diagnostic {
-    fn display(&self, format: Format) -> DisplayDiagnostic {
+    fn display(&self, format: Format) -> DisplayDiagnostic<'_> {
         DisplayDiagnostic {
             diagnostic: self,
             format,

crates/ruff_diagnostics/src/fix.rs

@@ -43,7 +43,7 @@ pub enum IsolationLevel {
 }
 
 /// A collection of [`Edit`] elements to be applied to a source file.
-#[derive(Debug, PartialEq, Eq, Clone, get_size2::GetSize)]
+#[derive(Debug, PartialEq, Eq, Clone, Hash, get_size2::GetSize)]
 #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
 pub struct Fix {
     /// The [`Edit`] elements to be applied, sorted by [`Edit::start`] in ascending order.

crates/ruff_formatter/src/buffer.rs

@@ -562,7 +562,7 @@ struct RemoveSoftLinebreaksSnapshot {
 pub trait BufferExtensions: Buffer + Sized {
     /// Returns a new buffer that calls the passed inspector for every element that gets written to the output
     #[must_use]
-    fn inspect<F>(&mut self, inspector: F) -> Inspect<Self::Context, F>
+    fn inspect<F>(&mut self, inspector: F) -> Inspect<'_, Self::Context, F>
     where
         F: FnMut(&FormatElement),
     {
@@ -607,7 +607,7 @@ pub trait BufferExtensions: Buffer + Sized {
     /// # }
     /// ```
     #[must_use]
-    fn start_recording(&mut self) -> Recording<Self> {
+    fn start_recording(&mut self) -> Recording<'_, Self> {
         Recording::new(self)
     }
 

crates/ruff_formatter/src/builders.rs

@@ -340,7 +340,7 @@ impl<Context> Format<Context> for SourcePosition {
 /// Creates a text from a dynamic string.
 ///
 /// This is done by allocating a new string internally.
-pub fn text(text: &str) -> Text {
+pub fn text(text: &str) -> Text<'_> {
     debug_assert_no_newlines(text);
 
     Text { text }
@@ -459,7 +459,10 @@ fn debug_assert_no_newlines(text: &str) {
 /// # }
 /// ```
 #[inline]
-pub fn line_suffix<Content, Context>(inner: &Content, reserved_width: u32) -> LineSuffix<Context>
+pub fn line_suffix<Content, Context>(
+    inner: &Content,
+    reserved_width: u32,
+) -> LineSuffix<'_, Context>
 where
     Content: Format<Context>,
 {
@@ -597,7 +600,10 @@ impl<Context> Format<Context> for LineSuffixBoundary {
 /// Use `Memoized.inspect(f)?.has_label(LabelId::of::<SomeLabelId>()` if you need to know if some content breaks that should
 /// only be written later.
 #[inline]
-pub fn labelled<Content, Context>(label_id: LabelId, content: &Content) -> FormatLabelled<Context>
+pub fn labelled<Content, Context>(
+    label_id: LabelId,
+    content: &Content,
+) -> FormatLabelled<'_, Context>
 where
     Content: Format<Context>,
 {
@@ -700,7 +706,7 @@ impl<Context> Format<Context> for Space {
 /// # }
 /// ```
 #[inline]
-pub fn indent<Content, Context>(content: &Content) -> Indent<Context>
+pub fn indent<Content, Context>(content: &Content) -> Indent<'_, Context>
 where
     Content: Format<Context>,
 {
@@ -771,7 +777,7 @@ impl<Context> std::fmt::Debug for Indent<'_, Context> {
 /// # }
 /// ```
 #[inline]
-pub fn dedent<Content, Context>(content: &Content) -> Dedent<Context>
+pub fn dedent<Content, Context>(content: &Content) -> Dedent<'_, Context>
 where
     Content: Format<Context>,
 {
@@ -846,7 +852,7 @@ impl<Context> std::fmt::Debug for Dedent<'_, Context> {
 ///
 /// This resembles the behaviour of Prettier's `align(Number.NEGATIVE_INFINITY, content)` IR element.
 #[inline]
-pub fn dedent_to_root<Content, Context>(content: &Content) -> Dedent<Context>
+pub fn dedent_to_root<Content, Context>(content: &Content) -> Dedent<'_, Context>
 where
     Content: Format<Context>,
 {
@@ -960,7 +966,7 @@ where
 ///
 /// - tab indentation: Printer indents the expression with two tabs because the `align` increases the indentation level.
 /// - space indentation: Printer indents the expression by 4 spaces (one indentation level) **and** 2 spaces for the align.
-pub fn align<Content, Context>(count: u8, content: &Content) -> Align<Context>
+pub fn align<Content, Context>(count: u8, content: &Content) -> Align<'_, Context>
 where
     Content: Format<Context>,
 {
@@ -1030,7 +1036,7 @@ impl<Context> std::fmt::Debug for Align<'_, Context> {
 /// # }
 /// ```
 #[inline]
-pub fn block_indent<Context>(content: &impl Format<Context>) -> BlockIndent<Context> {
+pub fn block_indent<Context>(content: &impl Format<Context>) -> BlockIndent<'_, Context> {
     BlockIndent {
         content: Argument::new(content),
         mode: IndentMode::Block,
@@ -1101,7 +1107,7 @@ pub fn block_indent<Context>(content: &impl Format<Context>) -> BlockIndent<Cont
 /// # }
 /// ```
 #[inline]
-pub fn soft_block_indent<Context>(content: &impl Format<Context>) -> BlockIndent<Context> {
+pub fn soft_block_indent<Context>(content: &impl Format<Context>) -> BlockIndent<'_, Context> {
     BlockIndent {
         content: Argument::new(content),
         mode: IndentMode::Soft,
@@ -1175,7 +1181,9 @@ pub fn soft_block_indent<Context>(content: &impl Format<Context>) -> BlockIndent
 /// # }
 /// ```
 #[inline]
-pub fn soft_line_indent_or_space<Context>(content: &impl Format<Context>) -> BlockIndent<Context> {
+pub fn soft_line_indent_or_space<Context>(
+    content: &impl Format<Context>,
+) -> BlockIndent<'_, Context> {
     BlockIndent {
         content: Argument::new(content),
         mode: IndentMode::SoftLineOrSpace,
@@ -1308,7 +1316,9 @@ impl<Context> std::fmt::Debug for BlockIndent<'_, Context> {
 /// # Ok(())
 /// # }
 /// ```
-pub fn soft_space_or_block_indent<Context>(content: &impl Format<Context>) -> BlockIndent<Context> {
+pub fn soft_space_or_block_indent<Context>(
+    content: &impl Format<Context>,
+) -> BlockIndent<'_, Context> {
     BlockIndent {
         content: Argument::new(content),
         mode: IndentMode::SoftSpace,
@@ -1388,7 +1398,7 @@ pub fn soft_space_or_block_indent<Context>(content: &impl Format<Context>) -> Bl
 /// # }
 /// ```
 #[inline]
-pub fn group<Context>(content: &impl Format<Context>) -> Group<Context> {
+pub fn group<Context>(content: &impl Format<Context>) -> Group<'_, Context> {
     Group {
         content: Argument::new(content),
         id: None,
@@ -1551,7 +1561,7 @@ impl<Context> std::fmt::Debug for Group<'_, Context> {
 #[inline]
 pub fn best_fit_parenthesize<Context>(
     content: &impl Format<Context>,
-) -> BestFitParenthesize<Context> {
+) -> BestFitParenthesize<'_, Context> {
     BestFitParenthesize {
         content: Argument::new(content),
         group_id: None,
@@ -1691,7 +1701,7 @@ impl<Context> std::fmt::Debug for BestFitParenthesize<'_, Context> {
 pub fn conditional_group<Content, Context>(
     content: &Content,
     condition: Condition,
-) -> ConditionalGroup<Context>
+) -> ConditionalGroup<'_, Context>
 where
     Content: Format<Context>,
 {
@@ -1852,7 +1862,7 @@ impl<Context> Format<Context> for ExpandParent {
 /// # }
 /// ```
 #[inline]
-pub fn if_group_breaks<Content, Context>(content: &Content) -> IfGroupBreaks<Context>
+pub fn if_group_breaks<Content, Context>(content: &Content) -> IfGroupBreaks<'_, Context>
 where
     Content: Format<Context>,
 {
@@ -1933,7 +1943,7 @@ where
 /// # }
 /// ```
 #[inline]
-pub fn if_group_fits_on_line<Content, Context>(flat_content: &Content) -> IfGroupBreaks<Context>
+pub fn if_group_fits_on_line<Content, Context>(flat_content: &Content) -> IfGroupBreaks<'_, Context>
 where
     Content: Format<Context>,
 {
@@ -2122,7 +2132,7 @@ impl<Context> std::fmt::Debug for IfGroupBreaks<'_, Context> {
 pub fn indent_if_group_breaks<Content, Context>(
     content: &Content,
     group_id: GroupId,
-) -> IndentIfGroupBreaks<Context>
+) -> IndentIfGroupBreaks<'_, Context>
 where
     Content: Format<Context>,
 {
@@ -2205,7 +2215,7 @@ impl<Context> std::fmt::Debug for IndentIfGroupBreaks<'_, Context> {
 /// # Ok(())
 /// # }
 /// ```
-pub fn fits_expanded<Content, Context>(content: &Content) -> FitsExpanded<Context>
+pub fn fits_expanded<Content, Context>(content: &Content) -> FitsExpanded<'_, Context>
 where
     Content: Format<Context>,
 {

crates/ruff_formatter/src/format_element.rs

@@ -197,7 +197,7 @@ pub const LINE_TERMINATORS: [char; 3] = ['\r', LINE_SEPARATOR, PARAGRAPH_SEPARAT
 
 /// Replace the line terminators matching the provided list with "\n"
 /// since its the only line break type supported by the printer
-pub fn normalize_newlines<const N: usize>(text: &str, terminators: [char; N]) -> Cow<str> {
+pub fn normalize_newlines<const N: usize>(text: &str, terminators: [char; N]) -> Cow<'_, str> {
     let mut result = String::new();
     let mut last_end = 0;
 

crates/ruff_formatter/src/format_element/document.rs

@@ -222,7 +222,7 @@ impl FormatContext for IrFormatContext<'_> {
         &IrFormatOptions
     }
 
-    fn source_code(&self) -> SourceCode {
+    fn source_code(&self) -> SourceCode<'_> {
         self.source_code
     }
 }

crates/ruff_formatter/src/lib.rs

@@ -193,7 +193,7 @@ pub trait FormatContext {
     fn options(&self) -> &Self::Options;
 
     /// Returns the source code from the document that gets formatted.
-    fn source_code(&self) -> SourceCode;
+    fn source_code(&self) -> SourceCode<'_>;
 }
 
 /// Options customizing how the source code should be formatted.
@@ -239,7 +239,7 @@ impl FormatContext for SimpleFormatContext {
         &self.options
     }
 
-    fn source_code(&self) -> SourceCode {
+    fn source_code(&self) -> SourceCode<'_> {
         SourceCode::new(&self.source_code)
     }
 }
@@ -326,7 +326,7 @@ where
         printer.print_with_indent(&self.document, indent)
     }
 
-    fn create_printer(&self) -> Printer {
+    fn create_printer(&self) -> Printer<'_> {
         let source_code = self.context.source_code();
         let print_options = self.context.options().as_print_options();
 

crates/ruff_graph/Cargo.toml

@@ -20,6 +20,7 @@ ty_python_semantic = { workspace = true }
 
 anyhow = { workspace = true }
 clap = { workspace = true, optional = true }
+memchr = { workspace = true }
 salsa = { workspace = true }
 schemars = { workspace = true, optional = true }
 serde = { workspace = true, optional = true }

crates/ruff_graph/src/collector.rs

@@ -1,3 +1,4 @@
+use crate::StringImports;
 use ruff_python_ast::visitor::source_order::{
     SourceOrderVisitor, walk_expr, walk_module, walk_stmt,
 };
@@ -10,13 +11,13 @@ pub(crate) struct Collector<'a> {
     /// The path to the current module.
     module_path: Option<&'a [String]>,
     /// Whether to detect imports from string literals.
-    string_imports: bool,
+    string_imports: StringImports,
     /// The collected imports from the Python AST.
     imports: Vec<CollectedImport>,
 }
 
 impl<'a> Collector<'a> {
-    pub(crate) fn new(module_path: Option<&'a [String]>, string_imports: bool) -> Self {
+    pub(crate) fn new(module_path: Option<&'a [String]>, string_imports: StringImports) -> Self {
         Self {
             module_path,
             string_imports,
@@ -118,7 +119,7 @@ impl<'ast> SourceOrderVisitor<'ast> for Collector<'_> {
             | Stmt::Continue(_)
             | Stmt::IpyEscapeCommand(_) => {
                 // Only traverse simple statements when string imports is enabled.
-                if self.string_imports {
+                if self.string_imports.enabled {
                     walk_stmt(self, stmt);
                 }
             }
@@ -126,20 +127,26 @@ impl<'ast> SourceOrderVisitor<'ast> for Collector<'_> {
     }
 
     fn visit_expr(&mut self, expr: &'ast Expr) {
-        if self.string_imports {
+        if self.string_imports.enabled {
             if let Expr::StringLiteral(ast::ExprStringLiteral {
                 value,
                 range: _,
                 node_index: _,
             }) = expr
             {
-                // Determine whether the string literal "looks like" an import statement: contains
-                // a dot, and consists solely of valid Python identifiers.
                 let value = value.to_str();
-                if let Some(module_name) = ModuleName::new(value) {
-                    self.imports.push(CollectedImport::Import(module_name));
+                // Determine whether the string literal "looks like" an import statement: contains
+                // the requisite number of dots, and consists solely of valid Python identifiers.
+                if self.string_imports.min_dots == 0
+                    || memchr::memchr_iter(b'.', value.as_bytes()).count()
+                        >= self.string_imports.min_dots
+                {
+                    if let Some(module_name) = ModuleName::new(value) {
+                        self.imports.push(CollectedImport::Import(module_name));
+                    }
                 }
             }
+
             walk_expr(self, expr);
         }
     }

crates/ruff_graph/src/db.rs

@@ -87,7 +87,7 @@ impl SourceDb for ModuleDb {
 
 #[salsa::db]
 impl Db for ModuleDb {
-    fn is_file_open(&self, file: File) -> bool {
+    fn should_check_file(&self, file: File) -> bool {
         !file.path(self).is_vendored_path()
     }
 

crates/ruff_graph/src/lib.rs

@@ -9,7 +9,7 @@ use ruff_python_parser::{Mode, ParseOptions, parse};
 use crate::collector::Collector;
 pub use crate::db::ModuleDb;
 use crate::resolver::Resolver;
-pub use crate::settings::{AnalyzeSettings, Direction};
+pub use crate::settings::{AnalyzeSettings, Direction, StringImports};
 
 mod collector;
 mod db;
@@ -26,7 +26,7 @@ impl ModuleImports {
         db: &ModuleDb,
         path: &SystemPath,
         package: Option<&SystemPath>,
-        string_imports: bool,
+        string_imports: StringImports,
     ) -> Result<Self> {
         // Read and parse the source code.
         let source = std::fs::read_to_string(path)?;
@@ -42,13 +42,11 @@ impl ModuleImports {
         // Resolve the imports.
         let mut resolved_imports = ModuleImports::default();
         for import in imports {
-            let Some(resolved) = Resolver::new(db).resolve(import) else {
-                continue;
-            };
-            let Some(path) = resolved.as_system_path() else {
-                continue;
-            };
-            resolved_imports.insert(path.to_path_buf());
+            for resolved in Resolver::new(db).resolve(import) {
+                if let Some(path) = resolved.as_system_path() {
+                    resolved_imports.insert(path.to_path_buf());
+                }
+            }
         }
 
         Ok(resolved_imports)

crates/ruff_graph/src/resolver.rs

@@ -1,5 +1,5 @@
 use ruff_db::files::FilePath;
-use ty_python_semantic::resolve_module;
+use ty_python_semantic::{ModuleName, resolve_module, resolve_real_module};
 
 use crate::ModuleDb;
 use crate::collector::CollectedImport;
@@ -16,24 +16,67 @@ impl<'a> Resolver<'a> {
     }
 
     /// Resolve the [`CollectedImport`] into a [`FilePath`].
-    pub(crate) fn resolve(&self, import: CollectedImport) -> Option<&'a FilePath> {
+    pub(crate) fn resolve(&self, import: CollectedImport) -> impl Iterator<Item = &'a FilePath> {
         match import {
             CollectedImport::Import(import) => {
-                let module = resolve_module(self.db, &import)?;
-                Some(module.file()?.path(self.db))
+                // Attempt to resolve the module (e.g., given `import foo`, look for `foo`).
+                let file = self.resolve_module(&import);
+
+                // If the file is a stub, look for the corresponding source file.
+                let source_file = file
+                    .is_some_and(|file| file.extension() == Some("pyi"))
+                    .then(|| self.resolve_real_module(&import))
+                    .flatten();
+
+                std::iter::once(file)
+                    .chain(std::iter::once(source_file))
+                    .flatten()
             }
             CollectedImport::ImportFrom(import) => {
                 // Attempt to resolve the member (e.g., given `from foo import bar`, look for `foo.bar`).
+                if let Some(file) = self.resolve_module(&import) {
+                    // If the file is a stub, look for the corresponding source file.
+                    let source_file = (file.extension() == Some("pyi"))
+                        .then(|| self.resolve_real_module(&import))
+                        .flatten();
+
+                    return std::iter::once(Some(file))
+                        .chain(std::iter::once(source_file))
+                        .flatten();
+                }
+
+                // Attempt to resolve the module (e.g., given `from foo import bar`, look for `foo`).
                 let parent = import.parent();
+                let file = parent
+                    .as_ref()
+                    .and_then(|parent| self.resolve_module(parent));
 
-                let module = resolve_module(self.db, &import).or_else(|| {
-                    // Attempt to resolve the module (e.g., given `from foo import bar`, look for `foo`).
+                // If the file is a stub, look for the corresponding source file.
+                let source_file = file
+                    .is_some_and(|file| file.extension() == Some("pyi"))
+                    .then(|| {
+                        parent
+                            .as_ref()
+                            .and_then(|parent| self.resolve_real_module(parent))
+                    })
+                    .flatten();
 
-                    resolve_module(self.db, &parent?)
-                })?;
-
-                Some(module.file()?.path(self.db))
+                std::iter::once(file)
+                    .chain(std::iter::once(source_file))
+                    .flatten()
             }
         }
     }
+
+    /// Resolves a module name to a module.
+    pub(crate) fn resolve_module(&self, module_name: &ModuleName) -> Option<&'a FilePath> {
+        let module = resolve_module(self.db, module_name)?;
+        Some(module.file(self.db)?.path(self.db))
+    }
+
+    /// Resolves a module name to a module (stubs not allowed).
+    fn resolve_real_module(&self, module_name: &ModuleName) -> Option<&'a FilePath> {
+        let module = resolve_real_module(self.db, module_name)?;
+        Some(module.file(self.db)?.path(self.db))
+    }
 }

crates/ruff_graph/src/settings.rs

@@ -11,7 +11,7 @@ pub struct AnalyzeSettings {
     pub exclude: FilePatternSet,
     pub preview: PreviewMode,
     pub target_version: PythonVersion,
-    pub detect_string_imports: bool,
+    pub string_imports: StringImports,
     pub include_dependencies: BTreeMap<PathBuf, (PathBuf, Vec<String>)>,
     pub extension: ExtensionMapping,
 }
@@ -26,7 +26,7 @@ impl fmt::Display for AnalyzeSettings {
                 self.exclude,
                 self.preview,
                 self.target_version,
-                self.detect_string_imports,
+                self.string_imports,
                 self.extension | debug,
                 self.include_dependencies | debug,
             ]
@@ -35,6 +35,31 @@ impl fmt::Display for AnalyzeSettings {
     }
 }
 
+#[derive(Debug, Copy, Clone, CacheKey)]
+pub struct StringImports {
+    pub enabled: bool,
+    pub min_dots: usize,
+}
+
+impl Default for StringImports {
+    fn default() -> Self {
+        Self {
+            enabled: false,
+            min_dots: 2,
+        }
+    }
+}
+
+impl fmt::Display for StringImports {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        if self.enabled {
+            write!(f, "enabled (min_dots: {})", self.min_dots)
+        } else {
+            write!(f, "disabled")
+        }
+    }
+}
+
 #[derive(Default, Debug, Copy, Clone, PartialEq, Eq, CacheKey)]
 #[cfg_attr(
     feature = "serde",

crates/ruff_linter/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "ruff_linter"
-version = "0.12.3"
+version = "0.12.8"
 publish = false
 authors = { workspace = true }
 edition = { workspace = true }
@@ -15,7 +15,7 @@ license = { workspace = true }
 [dependencies]
 ruff_annotate_snippets = { workspace = true }
 ruff_cache = { workspace = true }
-ruff_db = { workspace = true, features = ["serde"] }
+ruff_db = { workspace = true, features = ["junit", "serde"] }
 ruff_diagnostics = { workspace = true, features = ["serde"] }
 ruff_notebook = { workspace = true }
 ruff_macros = { workspace = true }
@@ -55,7 +55,6 @@ path-absolutize = { workspace = true, features = [
 pathdiff = { workspace = true }
 pep440_rs = { workspace = true }
 pyproject-toml = { workspace = true }
-quick-junit = { workspace = true }
 regex = { workspace = true }
 rustc-hash = { workspace = true }
 schemars = { workspace = true, optional = true }

crates/ruff_linter/resources/test/fixtures/eradicate/ERA001.py

@@ -89,3 +89,14 @@ print(1)
 # ///
 #
 # Foobar
+
+
+# Regression tests for https://github.com/astral-sh/ruff/issues/19713
+
+# mypy: ignore-errors
+# pyright: ignore-errors
+# pyrefly: ignore-errors
+# ty: ignore[unresolved-import]
+# pyrefly: ignore[unused-import]
+
+print(1)

crates/ruff_linter/resources/test/fixtures/flake8_bandit/S104.py

@@ -25,5 +25,5 @@ def my_func():
 
 # t-strings - all ok
 t"0.0.0.0"
-"0.0.0.0" t"0.0.0.0{expr}0.0.0.0"
-"0.0.0.0" f"0.0.0.0{expr}0.0.0.0" t"0.0.0.0{expr}0.0.0.0"
+t"0.0.0.0" t"0.0.0.0{expr}0.0.0.0"
+t"0.0.0.0" t"0.0.0.0{expr}0.0.0.0" t"0.0.0.0{expr}0.0.0.0"

crates/ruff_linter/resources/test/fixtures/flake8_blind_except/BLE.py

@@ -94,7 +94,7 @@ except Exception:
     logging.error("...", exc_info=True)
 
 
-from logging import error, exception
+from logging import critical, error, exception
 
 try:
     pass
@@ -114,6 +114,23 @@ except Exception:
     error("...", exc_info=None)
 
 
+try:
+    pass
+except Exception:
+    critical("...")
+
+
+try:
+    pass
+except Exception:
+    critical("...", exc_info=False)
+
+
+try:
+    pass
+except Exception:
+    critical("...", exc_info=None)
+
 try:
     pass
 except Exception:
@@ -125,6 +142,13 @@ try:
 except Exception:
     error("...", exc_info=True)
 
+
+try:
+    pass
+except Exception:
+    critical("...", exc_info=True)
+
+
 try:
     ...
 except Exception as e:
@@ -138,3 +162,86 @@ except Exception:
         exception("An error occurred")
     else:
         exception("An error occurred")
+
+# Test tuple exceptions
+try:
+    pass
+except (Exception,):
+    pass
+
+try:
+    pass
+except (Exception, ValueError):
+    pass
+
+try:
+    pass
+except (ValueError, Exception):
+    pass
+
+try:
+    pass
+except (ValueError, Exception) as e:
+    print(e)
+
+try:
+    pass
+except (BaseException, TypeError):
+    pass
+
+try:
+    pass
+except (TypeError, BaseException):
+    pass
+
+try:
+    pass
+except (Exception, BaseException):
+    pass
+
+try:
+    pass
+except (BaseException, Exception):
+    pass
+
+# Test nested tuples
+try:
+    pass
+except ((Exception, ValueError), TypeError):
+    pass
+
+try:
+    pass
+except (ValueError, (BaseException, TypeError)):
+    pass
+
+# Test valid tuple exceptions (should not trigger)
+try:
+    pass
+except (ValueError, TypeError):
+    pass
+
+try:
+    pass
+except (OSError, FileNotFoundError):
+    pass
+
+try:
+    pass
+except (OSError, FileNotFoundError) as e:
+    print(e)
+
+try:
+    pass
+except (Exception, ValueError):
+    critical("...", exc_info=True)
+
+try:
+    pass
+except (Exception, ValueError):
+    raise
+
+try:
+    pass
+except (Exception, ValueError) as e:
+    raise e

crates/ruff_linter/resources/test/fixtures/flake8_commas/COM81.py

@@ -650,3 +650,17 @@ f"""This is a test. {
     if True else
     "Don't add a trailing comma here ->"
 }"""
+
+type X[
+    T
+] = T
+def f[
+    T
+](): pass
+class C[
+    T
+]: pass
+
+type X[T,] = T
+def f[T,](): pass
+class C[T,]: pass

crates/ruff_linter/resources/test/fixtures/flake8_errmsg/EM.py

@@ -88,3 +88,25 @@ def f_multi_line_string2():
             example="example"
         )
     )
+
+
+def raise_typing_cast_exception():
+    import typing
+    raise typing.cast("Exception", None)
+
+
+def f_typing_cast_excluded():
+    from typing import cast
+    raise cast(RuntimeError, "This should not trigger EM101")
+
+
+def f_typing_cast_excluded_import():
+    import typing
+    raise typing.cast(RuntimeError, "This should not trigger EM101")
+
+
+def f_typing_cast_excluded_aliased():
+    from typing import cast as my_cast
+    raise my_cast(RuntimeError, "This should not trigger EM101")
+
+

crates/ruff_linter/resources/test/fixtures/flake8_pyi/PYI013.py

@@ -39,6 +39,11 @@ class NonEmptyWithInit:
         pass
 
 
+class NonEmptyChildWithInlineComment:
+    value: int
+    ... # preserve me
+
+
 class EmptyClass:
     ...
 

crates/ruff_linter/resources/test/fixtures/flake8_pyi/PYI013.pyi

@@ -38,6 +38,10 @@ class NonEmptyWithInit:
     def __init__():
         pass
 
+class NonEmptyChildWithInlineComment:
+    value: int
+    ... # preserve me
+
 # Not violations
 
 class EmptyClass: ...

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

@@ -142,3 +142,7 @@ 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
+
+# Regression test for https://github.com/astral-sh/ruff/issues/19403
+# Should throw duplicate union member but not fix
+isinstance(None, typing.Union[None, None])

crates/ruff_linter/resources/test/fixtures/flake8_simplify/SIM905.py

@@ -129,4 +129,35 @@ print(" x ".rsplit(maxsplit=0))
 print(" x ".rsplit(maxsplit=0))
 print(" x ".rsplit(sep=None, maxsplit=0))
 print("  x  ".rsplit(maxsplit=0))
-print("  x  ".rsplit(sep=None, maxsplit=0))
+print("  x  ".rsplit(sep=None, maxsplit=0))
+
+# https://github.com/astral-sh/ruff/issues/19581 - embedded quotes in raw strings
+r"""simple@example.com
+very.common@example.com
+FirstName.LastName@EasierReading.org
+x@example.com
+long.email-address-with-hyphens@and.subdomains.example.com
+user.name+tag+sorting@example.com
+name/surname@example.com
+xample@s.example
+" "@example.org
+"john..doe"@example.org
+mailhost!username@example.org
+"very.(),:;<>[]\".VERY.\"very@\\ \"very\".unusual"@strange.example.com
+user%example.com@example.org
+user-@example.org
+I❤️CHOCOLATE@example.com
+this\ still\"not\\allowed@example.com
+stellyamburrr985@example.com
+Abc.123@example.com
+user+mailbox/department=shipping@example.com
+!#$%&'*+-/=?^_`.{|}~@example.com
+"Abc@def"@example.com
+"Fred\ Bloggs"@example.com
+"Joe.\\Blow"@example.com""".split("\n")
+
+
+r"""first
+'no need' to escape
+"swap" quote style
+"use' ugly triple quotes""".split("\n")

crates/ruff_linter/resources/test/fixtures/flake8_use_pathlib/PTH201.py

@@ -1,4 +1,4 @@
-from pathlib import Path, PurePath
+from pathlib import Path, PurePath, PosixPath, PurePosixPath, WindowsPath, PureWindowsPath
 from pathlib import Path as pth
 
 
@@ -68,3 +68,11 @@ Path(".", "folder")
 PurePath(".", "folder")
 
 Path()
+
+from importlib.metadata import PackagePath
+
+_ = PosixPath(".")
+_ = PurePosixPath(".")
+_ = WindowsPath(".")
+_ = PureWindowsPath(".")
+_ = PackagePath(".")

crates/ruff_linter/resources/test/fixtures/flake8_use_pathlib/full_name.py

@@ -104,3 +104,6 @@ os.chmod(x)
 os.replace("src", "dst", src_dir_fd=1, dst_dir_fd=2)
 os.replace("src", "dst", src_dir_fd=1)
 os.replace("src", "dst", dst_dir_fd=2)
+
+os.getcwd()
+os.getcwdb()

crates/ruff_linter/resources/test/fixtures/flake8_use_pathlib/import_from.py

@@ -47,3 +47,19 @@ def _():
     from builtin import open
 
     with open(p) as _: ...  # No error
+
+file = "file_1.py"
+
+rename(file, "file_2.py")
+
+rename(
+    # commment 1
+    file, # comment 2
+    "file_2.py"
+    ,
+    # comment 3
+)
+
+rename(file, "file_2.py", src_dir_fd=None, dst_dir_fd=None)
+
+rename(file, "file_2.py", src_dir_fd=1)

crates/ruff_linter/resources/test/fixtures/isort/required_imports/docstring_followed_by_continuation.py

@@ -0,0 +1,3 @@
+"""Hello, world!"""\
+
+x = 1; y = 2

crates/ruff_linter/resources/test/fixtures/pep8_naming/N802.py

@@ -84,3 +84,25 @@ class MyRequestHandler(BaseHTTPRequestHandler):
     def dont_GET(self):
         pass
 
+
+from http.server import CGIHTTPRequestHandler
+
+
+class MyCGIRequestHandler(CGIHTTPRequestHandler):
+    def do_OPTIONS(self):
+        pass
+
+    def dont_OPTIONS(self):
+        pass
+
+
+from http.server import SimpleHTTPRequestHandler
+
+
+class MySimpleRequestHandler(SimpleHTTPRequestHandler):
+    def do_OPTIONS(self):
+        pass
+
+    def dont_OPTIONS(self):
+        pass
+

crates/ruff_linter/resources/test/fixtures/perflint/PERF401.py

@@ -278,3 +278,30 @@ def f():
     for i in src:
         if lambda: 0:
             dst.append(i)
+
+def f():
+    i = "xyz"
+    result = []
+    for i in range(3):
+        result.append(x for x in [i])
+
+def f():
+    i = "xyz"
+    result = []
+    for i in range(3):
+        result.append((x for x in [i]))
+
+G_INDEX = None
+def f():
+    global G_INDEX
+    result = []
+    for G_INDEX in range(3):
+        result.append(G_INDEX)
+
+def f():
+    NL_INDEX = None
+    def x():
+        nonlocal NL_INDEX
+        result = []
+        for NL_INDEX in range(3):
+            result.append(NL_INDEX)

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

@@ -0,0 +1,5 @@
+#
+x = 0 \
+#
++1
+print(x)

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

@@ -182,3 +182,13 @@ kwargs_with_maxsplit = {"maxsplit": 1}
 "1,2,3".split(",", **kwargs_with_maxsplit)[0]  # TODO: false positive
 kwargs_with_maxsplit = {"sep": ",", "maxsplit": 1}
 "1,2,3".split(**kwargs_with_maxsplit)[0]  # TODO: false positive
+
+
+## Test unpacked list literal args (starred expressions)
+# Errors
+"1,2,3".split(",", *[-1])[0]
+
+## Test unpacked list variable args
+# Errors
+args_list = [-1]
+"1,2,3".split(",", *args_list)[0]

crates/ruff_linter/resources/test/fixtures/pyupgrade/UP030_0.py

@@ -59,3 +59,7 @@ kwargs = {x: x for x in range(10)}
 "{1}_{0}".format(1, 2, *args)
 
 "{1}_{0}".format(1, 2)
+
+r"\d{{1,2}} {0}".format(42)
+
+"{{{0}}}".format(123)

crates/ruff_linter/resources/test/fixtures/refurb/FURB118.py

@@ -143,3 +143,23 @@ class NotAMethodButHardToDetect:
     # without risking false positives elsewhere or introducing complex heuristics
     # that users would find surprising and confusing
     FOO = sorted([x for x in BAR], key=lambda x: x.baz)
+
+# https://github.com/astral-sh/ruff/issues/19305
+import pytest
+
+@pytest.fixture
+def my_fixture_with_param(request):
+    return request.param
+
+@pytest.fixture()
+def my_fixture_with_param2(request):
+    return request.param
+
+
+# Decorated function (should be ignored)
+def custom_decorator(func):
+    return func
+
+@custom_decorator
+def add(x, y):
+    return x + y

crates/ruff_linter/resources/test/fixtures/refurb/FURB164.py

@@ -55,3 +55,12 @@ _ = Decimal(0.1)
 _ = Decimal(-0.5)
 _ = Decimal(5.0)
 _ = decimal.Decimal(4.2)
+
+# Cases with int and bool - should produce safe fixes
+_ = Decimal.from_float(1)
+_ = Decimal.from_float(True)
+
+# Cases with non-finite floats - should produce safe fixes
+_ = Decimal.from_float(float("-nan"))
+_ = Decimal.from_float(float("\x2dnan"))
+_ = Decimal.from_float(float("\N{HYPHEN-MINUS}nan"))