Bump 0.12.5 (#19528)

This PR adds support for "go to references" in the ty playground.

<img width="393" height="168" alt="image"
src="https://github.com/user-attachments/assets/ce3ae1bf-c17c-4510-9f77-20b10f6170c4"
/>

---------

Co-authored-by: UnboundVariable <unbound@gmail.com>

.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@c99cc51b309eee71a866715cfa08c922f11cf898 # v2.56.19
         with:
           tool: cargo-nextest
       - name: "Install cargo insta"
-        uses: taiki-e/install-action@c07504cae06f832dc8de08911c9a9c5cddb0d2d3 # v2.56.13
+        uses: taiki-e/install-action@c99cc51b309eee71a866715cfa08c922f11cf898 # v2.56.19
         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@c99cc51b309eee71a866715cfa08c922f11cf898 # v2.56.19
         with:
           tool: cargo-nextest
       - name: "Install cargo insta"
-        uses: taiki-e/install-action@c07504cae06f832dc8de08911c9a9c5cddb0d2d3 # v2.56.13
+        uses: taiki-e/install-action@c99cc51b309eee71a866715cfa08c922f11cf898 # v2.56.19
         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@c99cc51b309eee71a866715cfa08c922f11cf898 # v2.56.19
         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:
@@ -903,7 +903,7 @@ jobs:
         run: rustup show
 
       - name: "Install codspeed"
-        uses: taiki-e/install-action@c07504cae06f832dc8de08911c9a9c5cddb0d2d3 # v2.56.13
+        uses: taiki-e/install-action@c99cc51b309eee71a866715cfa08c922f11cf898 # v2.56.19
         with:
           tool: cargo-codspeed
 
@@ -936,7 +936,7 @@ jobs:
         run: rustup show
 
       - name: "Install codspeed"
-        uses: taiki-e/install-action@c07504cae06f832dc8de08911c9a9c5cddb0d2d3 # v2.56.13
+        uses: taiki-e/install-action@c99cc51b309eee71a866715cfa08c922f11cf898 # v2.56.19
         with:
           tool: cargo-codspeed
 

.github/workflows/daily_fuzz.yaml

@@ -38,7 +38,7 @@ jobs:
       - 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/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.
@@ -64,20 +68,20 @@ jobs:
       - uses: astral-sh/setup-uv@bd01e18f51369d5a26f1651c3cb451d3417e3bba # v6.3.1
       - 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/$(git -C ../typeshed rev-parse HEAD)" --allow-empty
       - name: Sync Linux docstrings
@@ -167,17 +171,17 @@ jobs:
           # consistent with the other typeshed stubs around them.
           # Typeshed formats code using black in their CI, so we just invoke
           # black on the stubs the same way that typeshed does.
-          uvx black crates/ty_vendored/vendor/typeshed/stdlib --config crates/ty_vendored/vendor/typeshed/pyproject.toml || true
+          uvx black "${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

@@ -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

@@ -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 \

.pre-commit-config.yaml

@@ -81,7 +81,7 @@ repos:
         pass_filenames: false # This makes it a lot faster
 
   - repo: https://github.com/astral-sh/ruff-pre-commit
-    rev: v0.12.3
+    rev: v0.12.4
     hooks:
       - id: ruff-format
       - id: ruff

CHANGELOG.md

@@ -1,5 +1,54 @@
 # Changelog
 
+## 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

CONTRIBUTING.md

@@ -266,6 +266,13 @@ Finally, regenerate the documentation and generated code with `cargo dev generat
 
 ## MkDocs
 
+> [!NOTE]
+>
+> The documentation uses Material for MkDocs Insiders, which is closed-source software.
+> This means only members of the Astral organization can preview the documentation exactly as it
+> will appear in production.
+> Outside contributors can still preview the documentation, but there will be some differences. Consult [the Material for MkDocs documentation](https://squidfunk.github.io/mkdocs-material/insiders/benefits/#features) for which features are exclusively available in the insiders version.
+
 To preview any changes to the documentation locally:
 
 1. Install the [Rust toolchain](https://www.rust-lang.org/tools/install).

Cargo.lock

@@ -261,6 +261,18 @@ version = "2.9.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "1b8e56985ec62d17e9c1001dc89c88ecd7dc08e47eba5ec7c29c7b5eeecde967"
 
+[[package]]
+name = "bitvec"
+version = "1.0.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1bc2832c24239b0141d5674bb9174f9d68a8b5b3f2753311927c172ca46f7e9c"
+dependencies = [
+ "funty",
+ "radium",
+ "tap",
+ "wyz",
+]
+
 [[package]]
 name = "block-buffer"
 version = "0.10.4"
@@ -1121,6 +1133,12 @@ dependencies = [
  "libc",
 ]
 
+[[package]]
+name = "funty"
+version = "2.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e6d5a32815ae3f33302d95fdcb2ce17862f8c65363dcfd29360480ba1001fc9c"
+
 [[package]]
 name = "generic-array"
 version = "0.14.7"
@@ -1557,6 +1575,15 @@ dependencies = [
  "memoffset",
 ]
 
+[[package]]
+name = "inventory"
+version = "0.3.20"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ab08d7cd2c5897f2c949e5383ea7c7db03fb19130ffcfbf7eda795137ae3cb83"
+dependencies = [
+ "rustversion",
+]
+
 [[package]]
 name = "is-docker"
 version = "0.2.0"
@@ -2123,16 +2150,6 @@ version = "0.1.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "b15813163c1d831bf4a13c3610c05c0d03b39feb07f7e09fa234dac9b15aaf39"
 
-[[package]]
-name = "papaya"
-version = "0.2.3"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f92dd0b07c53a0a0c764db2ace8c541dc47320dad97c2200c2a637ab9dd2328f"
-dependencies = [
- "equivalent",
- "seize",
-]
-
 [[package]]
 name = "parking_lot"
 version = "0.12.3"
@@ -2549,6 +2566,12 @@ version = "5.2.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "74765f6d916ee2faa39bc8e68e4f3ed8949b48cccdac59983d287a7cb71ce9c5"
 
+[[package]]
+name = "radium"
+version = "0.7.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "dc33ff2d4973d518d823d61aa239014831e521c75da58e3df4840d3f47749d09"
+
 [[package]]
 name = "rand"
 version = "0.8.5"
@@ -2562,9 +2585,9 @@ dependencies = [
 
 [[package]]
 name = "rand"
-version = "0.9.1"
+version = "0.9.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9fbfd9d094a40bf3ae768db9361049ace4c0e04a4fd6b359518bd7b73a73dd97"
+checksum = "6db2770f06117d490610c7488547d543617b21bfa07796d7a12f6f1bd53850d1"
 dependencies = [
  "rand_chacha 0.9.0",
  "rand_core 0.9.3",
@@ -2711,7 +2734,7 @@ dependencies = [
 
 [[package]]
 name = "ruff"
-version = "0.12.3"
+version = "0.12.5"
 dependencies = [
  "anyhow",
  "argfile",
@@ -2828,7 +2851,6 @@ dependencies = [
  "anstyle",
  "arc-swap",
  "camino",
- "countme",
  "dashmap",
  "dunce",
  "etcetera",
@@ -2839,6 +2861,7 @@ dependencies = [
  "insta",
  "matchit",
  "path-slash",
+ "quick-junit",
  "ruff_annotate_snippets",
  "ruff_cache",
  "ruff_diagnostics",
@@ -2962,7 +2985,7 @@ dependencies = [
 
 [[package]]
 name = "ruff_linter"
-version = "0.12.3"
+version = "0.12.5"
 dependencies = [
  "aho-corasick",
  "anyhow",
@@ -2987,7 +3010,6 @@ dependencies = [
  "pathdiff",
  "pep440_rs",
  "pyproject-toml",
- "quick-junit",
  "regex",
  "ruff_annotate_snippets",
  "ruff_cache",
@@ -3042,7 +3064,7 @@ version = "0.0.0"
 dependencies = [
  "anyhow",
  "itertools 0.14.0",
- "rand 0.9.1",
+ "rand 0.9.2",
  "ruff_diagnostics",
  "ruff_source_file",
  "ruff_text_size",
@@ -3295,7 +3317,7 @@ dependencies = [
 
 [[package]]
 name = "ruff_wasm"
-version = "0.12.3"
+version = "0.12.5"
 dependencies = [
  "console_error_panic_hook",
  "console_log",
@@ -3409,7 +3431,7 @@ checksum = "28d3b2b1366ec20994f1fd18c3c594f05c5dd4bc44d8bb0c1c632c8d6829481f"
 [[package]]
 name = "salsa"
 version = "0.23.0"
-source = "git+https://github.com/salsa-rs/salsa?rev=fc00eba89e5dcaa5edba51c41aa5f309b5cb126b#fc00eba89e5dcaa5edba51c41aa5f309b5cb126b"
+source = "git+https://github.com/salsa-rs/salsa?rev=dba66f1a37acca014c2402f231ed5b361bd7d8fe#dba66f1a37acca014c2402f231ed5b361bd7d8fe"
 dependencies = [
  "boxcar",
  "compact_str",
@@ -3419,7 +3441,7 @@ dependencies = [
  "hashlink",
  "indexmap",
  "intrusive-collections",
- "papaya",
+ "inventory",
  "parking_lot",
  "portable-atomic",
  "rayon",
@@ -3434,12 +3456,12 @@ dependencies = [
 [[package]]
 name = "salsa-macro-rules"
 version = "0.23.0"
-source = "git+https://github.com/salsa-rs/salsa?rev=fc00eba89e5dcaa5edba51c41aa5f309b5cb126b#fc00eba89e5dcaa5edba51c41aa5f309b5cb126b"
+source = "git+https://github.com/salsa-rs/salsa?rev=dba66f1a37acca014c2402f231ed5b361bd7d8fe#dba66f1a37acca014c2402f231ed5b361bd7d8fe"
 
 [[package]]
 name = "salsa-macros"
 version = "0.23.0"
-source = "git+https://github.com/salsa-rs/salsa?rev=fc00eba89e5dcaa5edba51c41aa5f309b5cb126b#fc00eba89e5dcaa5edba51c41aa5f309b5cb126b"
+source = "git+https://github.com/salsa-rs/salsa?rev=dba66f1a37acca014c2402f231ed5b361bd7d8fe#dba66f1a37acca014c2402f231ed5b361bd7d8fe"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -3492,16 +3514,6 @@ version = "4.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "1c107b6f4780854c8b126e228ea8869f4d7b71260f962fefb57b996b8959ba6b"
 
-[[package]]
-name = "seize"
-version = "0.5.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e4b8d813387d566f627f3ea1b914c068aac94c40ae27ec43f5f33bde65abefe7"
-dependencies = [
- "libc",
- "windows-sys 0.52.0",
-]
-
 [[package]]
 name = "serde"
 version = "1.0.219"
@@ -3546,9 +3558,9 @@ dependencies = [
 
 [[package]]
 name = "serde_json"
-version = "1.0.140"
+version = "1.0.141"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "20068b6e96dc6c9bd23e01df8827e6c7e1f2fddd43c21810382803c136b99373"
+checksum = "30b9eff21ebe718216c6ec64e1d9ac57087aad11efc64e32002bce4a0d4c03d3"
 dependencies = [
  "itoa",
  "memchr",
@@ -3738,23 +3750,22 @@ checksum = "7da8b5736845d9f2fcb837ea5d9e2628564b3b043a70948a3f0b778838c5fb4f"
 
 [[package]]
 name = "strum"
-version = "0.27.1"
+version = "0.27.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f64def088c51c9510a8579e3c5d67c65349dcf755e5479ad3d010aa6454e2c32"
+checksum = "af23d6f6c1a224baef9d3f61e287d2761385a5b88fdab4eb4c6f11aeb54c4bcf"
 dependencies = [
  "strum_macros",
 ]
 
 [[package]]
 name = "strum_macros"
-version = "0.27.1"
+version = "0.27.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c77a8c5abcaf0f9ce05d62342b7d298c346515365c36b673df4ebe3ced01fde8"
+checksum = "7695ce3845ea4b33927c055a39dc438a45b059f7c1b3d91d38d10355fb8cbca7"
 dependencies = [
  "heck",
  "proc-macro2",
  "quote",
- "rustversion",
  "syn",
 ]
 
@@ -3780,6 +3791,12 @@ dependencies = [
  "syn",
 ]
 
+[[package]]
+name = "tap"
+version = "1.0.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "55937e1799185b12863d447f42597ed69d9928686b8d88a1df17376a097d8369"
+
 [[package]]
 name = "tempfile"
 version = "3.20.0"
@@ -4194,6 +4211,7 @@ version = "0.0.0"
 dependencies = [
  "bitflags 2.9.1",
  "insta",
+ "itertools 0.14.0",
  "regex",
  "ruff_db",
  "ruff_python_ast",
@@ -4202,11 +4220,10 @@ dependencies = [
  "ruff_source_file",
  "ruff_text_size",
  "rustc-hash",
- "salsa",
  "smallvec",
  "tracing",
+ "ty_project",
  "ty_python_semantic",
- "ty_vendored",
 ]
 
 [[package]]
@@ -4240,7 +4257,6 @@ dependencies = [
  "thiserror 2.0.12",
  "toml 0.9.2",
  "tracing",
- "ty_ide",
  "ty_python_semantic",
  "ty_vendored",
 ]
@@ -4251,6 +4267,7 @@ version = "0.0.0"
 dependencies = [
  "anyhow",
  "bitflags 2.9.1",
+ "bitvec",
  "camino",
  "colored 3.0.0",
  "compact_str",
@@ -4287,6 +4304,7 @@ dependencies = [
  "strum_macros",
  "tempfile",
  "test-case",
+ "thin-vec",
  "thiserror 2.0.12",
  "tracing",
  "ty_python_semantic",
@@ -4300,11 +4318,15 @@ name = "ty_server"
 version = "0.0.0"
 dependencies = [
  "anyhow",
+ "bitflags 2.9.1",
  "crossbeam",
+ "dunce",
+ "insta",
  "jod-thread",
  "libc",
  "lsp-server",
  "lsp-types",
+ "regex",
  "ruff_db",
  "ruff_notebook",
  "ruff_python_ast",
@@ -4315,6 +4337,7 @@ dependencies = [
  "serde",
  "serde_json",
  "shellexpand",
+ "tempfile",
  "thiserror 2.0.12",
  "tracing",
  "tracing-subscriber",
@@ -4574,7 +4597,7 @@ checksum = "3cf4199d1e5d15ddd86a694e4d0dffa9c323ce759fea589f00fef9d81cc1931d"
 dependencies = [
  "getrandom 0.3.3",
  "js-sys",
- "rand 0.9.1",
+ "rand 0.9.2",
  "uuid-macro-internal",
  "wasm-bindgen",
 ]
@@ -5103,6 +5126,15 @@ version = "0.6.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "ea2f10b9bb0928dfb1b42b65e1f9e36f7f54dbdf08457afefb38afcdec4fa2bb"
 
+[[package]]
+name = "wyz"
+version = "0.5.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "05f360fc0b24296329c78fda852a1e9ae82de9cf7b27dae4b7f62f118f77b9ed"
+dependencies = [
+ "tap",
+]
+
 [[package]]
 name = "yansi"
 version = "1.0.1"

Cargo.toml

@@ -57,6 +57,9 @@ 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" }
@@ -138,7 +141,7 @@ regex-automata = { version = "0.4.9" }
 rustc-hash = { version = "2.0.0" }
 rustc-stable-hash = { version = "0.1.2" }
 # When updating salsa, make sure to also update the revision in `fuzz/Cargo.toml`
-salsa = { git = "https://github.com/salsa-rs/salsa", rev = "fc00eba89e5dcaa5edba51c41aa5f309b5cb126b" }
+salsa = { git = "https://github.com/salsa-rs/salsa", rev = "dba66f1a37acca014c2402f231ed5b361bd7d8fe" }
 schemars = { version = "0.8.16" }
 seahash = { version = "4.1.0" }
 serde = { version = "1.0.197", features = ["derive"] }
@@ -150,7 +153,7 @@ 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",
@@ -163,6 +166,7 @@ strum_macros = { version = "0.27.0" }
 syn = { version = "2.0.55" }
 tempfile = { version = "3.9.0" }
 test-case = { version = "3.3.1" }
+thin-vec = { version = "0.2.14" }
 thiserror = { version = "2.0.0" }
 tikv-jemallocator = { version = "0.6.0" }
 toml = { version = "0.9.0" }

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/0.12.5/install.sh | sh
+powershell -c "irm https://astral.sh/ruff/0.12.5/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: v0.12.5
   hooks:
     # Run the linter.
     - id: ruff-check

crates/ruff/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "ruff"
-version = "0.12.3"
+version = "0.12.5"
 publish = true
 authors = { workspace = true }
 edition = { workspace = true }

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/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/lint.rs

@@ -993,6 +993,7 @@ fn value_given_to_table_key_is_not_inline_table_2() {
     - `lint.exclude`
     - `lint.preview`
     - `lint.typing-extensions`
+    - `lint.future-annotations`
 
     For more information, try '--help'.
     ");
@@ -5717,8 +5718,11 @@ 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]"),
@@ -5744,3 +5748,25 @@ match 42:  # invalid-syntax
 
     Ok(())
 }
+
+#[test]
+fn future_annotations_preview_warning() {
+    assert_cmd_snapshot!(
+        Command::new(get_cargo_bin(BIN_NAME))
+            .args(STDIN_BASE_OPTIONS)
+            .args(["--config", "lint.future-annotations = true"])
+            .args(["--select", "F"])
+            .arg("--no-preview")
+            .arg("-")
+            .pass_stdin("1"),
+        @r"
+    success: true
+    exit_code: 0
+    ----- stdout -----
+    All checks passed!
+
+    ----- stderr -----
+    warning: The `lint.future-annotations` setting will have no effect because `preview` is disabled
+    ",
+    );
+}

crates/ruff/tests/snapshots/lint__output_format_junit.snap

@@ -25,7 +25,7 @@ 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">
+        <testcase name="org.ruff.invalid-syntax" 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>
     </testsuite>

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]));
 
@@ -525,14 +527,21 @@ 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 +551,7 @@ 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 +619,7 @@ fn datetype(criterion: &mut Criterion) {
             max_dep_date: "2025-07-04",
             python_version: PythonVersion::PY313,
         },
-        0,
+        2,
     );
 
     bench_project(&benchmark, criterion);

crates/ruff_db/Cargo.toml

@@ -25,7 +25,6 @@ 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 +33,7 @@ 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 +56,13 @@ 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

@@ -1,6 +1,6 @@
 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;
@@ -122,7 +122,14 @@ 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.
@@ -377,9 +384,15 @@ 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.
@@ -565,7 +578,10 @@ 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(),
@@ -643,7 +659,7 @@ impl SubDiagnostic {
 
 #[derive(Debug, Clone, Eq, PartialEq, get_size2::GetSize)]
 struct SubDiagnosticInner {
-    severity: Severity,
+    severity: SubDiagnosticSeverity,
     message: DiagnosticMessage,
     annotations: Vec<Annotation>,
 }
@@ -1170,6 +1186,32 @@ 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, 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 +1238,15 @@ 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 +1275,35 @@ 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 +1313,9 @@ impl Default for DisplayDiagnosticConfig {
             color: false,
             context: 2,
             preview: false,
+            hide_severity: false,
+            show_fix_status: false,
+            fix_applicability: Applicability::Safe,
         }
     }
 }
@@ -1282,6 +1365,9 @@ 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.

crates/ruff_db/src/diagnostic/render.rs

@@ -9,7 +9,7 @@ use ruff_notebook::{Notebook, NotebookIndex};
 use ruff_source_file::{LineIndex, OneIndexed, SourceCode};
 use ruff_text_size::{TextRange, TextSize};
 
-use crate::diagnostic::stylesheet::{DiagnosticStylesheet, fmt_styled};
+use crate::diagnostic::stylesheet::DiagnosticStylesheet;
 use crate::{
     Db,
     files::File,
@@ -18,18 +18,23 @@ 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 +107,7 @@ 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 +120,8 @@ impl std::fmt::Display for DisplayDiagnostics<'_> {
                     AnnotateRenderer::styled()
                 } else {
                     AnnotateRenderer::plain()
-                };
+                }
+                .cut_indicator("…");
 
                 renderer = renderer
                     .error(stylesheet.error)
@@ -196,6 +161,10 @@ 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(())
@@ -249,7 +218,7 @@ impl<'a> Resolved<'a> {
 /// both.)
 #[derive(Debug)]
 struct ResolvedDiagnostic<'a> {
-    severity: Severity,
+    level: AnnotateLevel,
     id: Option<String>,
     message: String,
     annotations: Vec<ResolvedAnnotation<'a>>,
@@ -274,7 +243,7 @@ impl<'a> ResolvedDiagnostic<'a> {
         let id = Some(diag.inner.id.to_string());
         let message = diag.inner.message.as_str().to_string();
         ResolvedDiagnostic {
-            severity: diag.inner.severity,
+            level: diag.inner.severity.to_annotate(),
             id,
             message,
             annotations,
@@ -297,7 +266,7 @@ impl<'a> ResolvedDiagnostic<'a> {
             })
             .collect();
         ResolvedDiagnostic {
-            severity: diag.inner.severity,
+            level: diag.inner.severity.to_annotate(),
             id: None,
             message: diag.inner.message.as_str().to_string(),
             annotations,
@@ -364,7 +333,7 @@ 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,
@@ -452,7 +421,7 @@ 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.
     ///
@@ -471,7 +440,6 @@ struct RenderableDiagnostic<'r> {
 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 +447,7 @@ impl RenderableDiagnostic<'_> {
                 .iter()
                 .map(|snippet| snippet.to_annotate(path))
         });
-        let mut message = level.title(self.message);
+        let mut message = self.level.title(self.message);
         if let Some(id) = self.id {
             message = message.id(id);
         }
@@ -855,9 +823,12 @@ fn relativize_path<'p>(cwd: &SystemPath, path: &'p str) -> &'p str {
 #[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 +1512,7 @@ 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 +1541,15 @@ 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 +2271,27 @@ 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);
@@ -2363,7 +2355,7 @@ 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.
@@ -2384,7 +2376,11 @@ 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 }
         }
@@ -2487,6 +2483,12 @@ watermelon
             self.diag.set_noqa_offset(noqa_offset);
             self
         }
+
+        /// Adds a "help" sub-diagnostic with the given message.
+        fn help(mut self, message: impl IntoDiagnosticMessage) -> DiagnosticBuilder<'e> {
+            self.diag.help(message);
+            self
+        }
     }
 
     /// A helper builder for tersely populating a `SubDiagnostic`.
@@ -2593,7 +2595,8 @@ 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 +2609,8 @@ 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),
@@ -2658,6 +2657,25 @@ if call(foo
     }
 
     /// Create Ruff-style diagnostics for testing the various output formats for a notebook.
+    ///
+    /// 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`.
     #[allow(
         dead_code,
         reason = "This is currently only used for JSON but will be needed soon for other formats"
@@ -2713,7 +2731,8 @@ if call(foo
 
         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 +2745,8 @@ 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 +2759,8 @@ 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/concise.rs

@@ -0,0 +1,195 @@
+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)
+                    )?;
+                }
+                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: SyntaxError: Expected one or more symbol names after import
+        syntax_errors.py:3:12: SyntaxError: 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] SyntaxError: Expected one or more symbol names after import
+        syntax_errors.py:3:12: error[invalid-syntax] SyntaxError: 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 +1,66 @@
+#[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::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]: SyntaxError: 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]: SyntaxError: Expected ')', found newline
+         --> syntax_errors.py:3:12
+          |
+        1 | from os import
+        2 |
+        3 | if call(foo
+          |            ^
+        4 |     def bar():
+        5 |         pass
+          |
+        ");
+    }
+}

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

@@ -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,

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__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

@@ -1,15 +1,14 @@
 ---
-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="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" classname="syntax_errors" line="1" column="15">
+        <testcase name="org.ruff.invalid-syntax" classname="syntax_errors" line="1" column="15">
             <failure message="SyntaxError: Expected one or more symbol names after import">line 1, col 15, SyntaxError: Expected one or more symbol names after import</failure>
         </testcase>
-        <testcase name="org.ruff" classname="syntax_errors" line="3" column="12">
+        <testcase name="org.ruff.invalid-syntax" classname="syntax_errors" line="3" column="12">
             <failure message="SyntaxError: Expected &apos;)&apos;, found newline">line 3, col 12, SyntaxError: Expected &apos;)&apos;, found newline</failure>
         </testcase>
     </testsuite>

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/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;
@@ -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 }),
     }
 }
 
@@ -125,8 +119,6 @@ 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>,
 }

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/resolver.rs

@@ -20,7 +20,7 @@ impl<'a> Resolver<'a> {
         match import {
             CollectedImport::Import(import) => {
                 let module = resolve_module(self.db, &import)?;
-                Some(module.file()?.path(self.db))
+                Some(module.file(self.db)?.path(self.db))
             }
             CollectedImport::ImportFrom(import) => {
                 // Attempt to resolve the member (e.g., given `from foo import bar`, look for `foo.bar`).
@@ -32,7 +32,7 @@ impl<'a> Resolver<'a> {
                     resolve_module(self.db, &parent?)
                 })?;
 
-                Some(module.file()?.path(self.db))
+                Some(module.file(self.db)?.path(self.db))
             }
         }
     }

crates/ruff_linter/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "ruff_linter"
-version = "0.12.3"
+version = "0.12.5"
 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/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_type_checking/TC001-3_future.py

@@ -0,0 +1,10 @@
+from collections import Counter
+
+from elsewhere import third_party
+
+from . import first_party
+
+
+def f(x: first_party.foo): ...
+def g(x: third_party.bar): ...
+def h(x: Counter): ...

crates/ruff_linter/resources/test/fixtures/flake8_type_checking/TC001_future.py

@@ -0,0 +1,68 @@
+def f():
+    from . import first_party
+
+    def f(x: first_party.foo): ...
+
+
+# Type parameter bounds
+def g():
+    from . import foo
+
+    class C[T: foo.Ty]: ...
+
+
+def h():
+    from . import foo
+
+    def f[T: foo.Ty](x: T): ...
+
+
+def i():
+    from . import foo
+
+    type Alias[T: foo.Ty] = list[T]
+
+
+# Type parameter defaults
+def j():
+    from . import foo
+
+    class C[T = foo.Ty]: ...
+
+
+def k():
+    from . import foo
+
+    def f[T = foo.Ty](x: T): ...
+
+
+def l():
+    from . import foo
+
+    type Alias[T = foo.Ty] = list[T]
+
+
+# non-generic type alias
+def m():
+    from . import foo
+
+    type Alias = foo.Ty
+
+
+# unions
+from typing import Union
+
+
+def n():
+    from . import foo
+
+    def f(x: Union[foo.Ty, int]): ...
+    def g(x: foo.Ty | int): ...
+
+
+# runtime and typing usage
+def o():
+    from . import foo
+
+    def f(x: foo.Ty):
+        return foo.Ty()

crates/ruff_linter/resources/test/fixtures/flake8_type_checking/TC001_future_present.py

@@ -0,0 +1,6 @@
+from __future__ import annotations
+
+from . import first_party
+
+
+def f(x: first_party.foo): ...

crates/ruff_linter/resources/test/fixtures/flake8_use_pathlib/PTH210.py

@@ -54,6 +54,13 @@ windows_path.with_suffix(r"s")
 windows_path.with_suffix(u'' "json")
 windows_path.with_suffix(suffix="js")
 
+Path().with_suffix(".")
+Path().with_suffix("py")
+PosixPath().with_suffix("py")
+PurePath().with_suffix("py")
+PurePosixPath().with_suffix("py")
+PureWindowsPath().with_suffix("py")
+WindowsPath().with_suffix("py")
 
 ### No errors
 path.with_suffix()

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/whitespace.py

@@ -0,0 +1,5 @@
+# This is a regression test for https://github.com/astral-sh/ruff/issues/19310
+# there is a (potentially invisible) unicode formfeed character (000C) between "docstring" and the semicolon
+"docstring"; print(
+    f"{__doc__=}",
+)

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 +278,15 @@ 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]))

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/unspecified_encoding.py

@@ -91,9 +91,16 @@ Path("foo.txt").write_text(text, encoding="utf-8")
 Path("foo.txt").write_text(text, *args)
 Path("foo.txt").write_text(text, **kwargs)
 
-# Violation but not detectable
+# https://github.com/astral-sh/ruff/issues/19294
 x = Path("foo.txt")
 x.open()
 
 # https://github.com/astral-sh/ruff/issues/18107
 codecs.open("plw1514.py", "r", "utf-8").close() # this is fine
+
+# function argument annotated as Path
+from pathlib import Path
+
+def format_file(file: Path):
+    with file.open() as f:
+        contents = f.read()

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

@@ -27,7 +27,24 @@ _ = Decimal.from_float(float("   -inF\n \t"))
 _ = Decimal.from_float(float("  InfinIty \n\t "))
 _ = Decimal.from_float(float("   -InfinIty\n \t"))
 
-# OK
+# Cases with keyword arguments - should produce unsafe fixes
+_ = Fraction.from_decimal(dec=Decimal("4.2"))
+_ = Decimal.from_float(f=4.2)
+
+# Cases with invalid argument counts - should not get fixes
+_ = Fraction.from_decimal(Decimal("4.2"), 1)
+_ = Decimal.from_float(4.2, None)
+
+# Cases with wrong keyword arguments - should not get fixes  
+_ = Fraction.from_decimal(numerator=Decimal("4.2"))
+_ = Decimal.from_float(value=4.2)
+
+# Cases with type validation issues - should produce unsafe fixes
+_ = Decimal.from_float("4.2")  # Invalid type for from_float
+_ = Fraction.from_decimal(4.2)  # Invalid type for from_decimal
+_ = Fraction.from_float("4.2")  # Invalid type for from_float
+
+# OK - should not trigger the rule
 _ = Fraction(0.1)
 _ = Fraction(-0.5)
 _ = Fraction(5.0)

crates/ruff_linter/resources/test/fixtures/ruff/RUF027_0.py

@@ -79,3 +79,8 @@ def in_type_def():
     from typing import cast
     a = 'int'
     cast('f"{a}"','11')
+
+# Regression test for parser bug
+# https://github.com/astral-sh/ruff/issues/18860
+def fuzz_bug():
+    c('{\t"i}')

crates/ruff_linter/resources/test/fixtures/ruff/RUF055_3.py

@@ -0,0 +1,24 @@
+import re
+
+b_src = b"abc"
+
+# Should be replaced with `b_src.replace(rb"x", b"y")`
+re.sub(rb"x", b"y", b_src)
+
+# Should be replaced with `b_src.startswith(rb"abc")`
+if re.match(rb"abc", b_src):
+    pass
+
+# Should be replaced with `rb"x" in b_src`
+if re.search(rb"x", b_src):
+    pass
+
+# Should be replaced with `b_src.split(rb"abc")`
+re.split(rb"abc", b_src)
+
+# Patterns containing metacharacters should NOT be replaced
+re.sub(rb"ab[c]", b"", b_src)
+re.match(rb"ab[c]", b_src)
+re.search(rb"ab[c]", b_src)
+re.fullmatch(rb"ab[c]", b_src)
+re.split(rb"ab[c]", b_src) 

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

@@ -71,7 +71,7 @@ pub(crate) fn deferred_scopes(checker: &Checker) {
                         flake8_type_checking::helpers::is_valid_runtime_import(
                             binding,
                             &checker.semantic,
-                            &checker.settings().flake8_type_checking,
+                            checker.settings(),
                         )
                     })
                     .collect()

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

@@ -1039,15 +1039,10 @@ pub(crate) fn expression(expr: &Expr, checker: &Checker) {
                 flake8_simplify::rules::zip_dict_keys_and_values(checker, call);
             }
             if checker.any_rule_enabled(&[
-                Rule::OsChmod,
                 Rule::OsMkdir,
                 Rule::OsMakedirs,
-                Rule::OsRename,
-                Rule::OsReplace,
-                Rule::OsGetcwd,
                 Rule::OsStat,
                 Rule::OsPathJoin,
-                Rule::OsPathSamefile,
                 Rule::OsPathSplitext,
                 Rule::BuiltinOpen,
                 Rule::PyPath,
@@ -1110,6 +1105,21 @@ pub(crate) fn expression(expr: &Expr, checker: &Checker) {
                 if checker.is_rule_enabled(Rule::OsReadlink) {
                     flake8_use_pathlib::rules::os_readlink(checker, call, segments);
                 }
+                if checker.is_rule_enabled(Rule::OsGetcwd) {
+                    flake8_use_pathlib::rules::os_getcwd(checker, call, segments);
+                }
+                if checker.is_rule_enabled(Rule::OsChmod) {
+                    flake8_use_pathlib::rules::os_chmod(checker, call, segments);
+                }
+                if checker.is_rule_enabled(Rule::OsRename) {
+                    flake8_use_pathlib::rules::os_rename(checker, call, segments);
+                }
+                if checker.is_rule_enabled(Rule::OsReplace) {
+                    flake8_use_pathlib::rules::os_replace(checker, call, segments);
+                }
+                if checker.is_rule_enabled(Rule::OsPathSamefile) {
+                    flake8_use_pathlib::rules::os_path_samefile(checker, call, segments);
+                }
                 if checker.is_rule_enabled(Rule::PathConstructorCurrentDirectory) {
                     flake8_use_pathlib::rules::path_constructor_current_directory(
                         checker, call, segments,

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

@@ -2770,11 +2770,10 @@ impl<'a> Checker<'a> {
 
                         self.semantic.restore(snapshot);
 
-                        if self.semantic.in_typing_only_annotation() {
-                            if self.is_rule_enabled(Rule::QuotedAnnotation) {
-                                pyupgrade::rules::quoted_annotation(self, annotation, range);
-                            }
+                        if self.is_rule_enabled(Rule::QuotedAnnotation) {
+                            pyupgrade::rules::quoted_annotation(self, annotation, range);
                         }
+
                         if self.source_type.is_stub() {
                             if self.is_rule_enabled(Rule::QuotedAnnotationInStub) {
                                 flake8_pyi::rules::quoted_annotation_in_stub(

crates/ruff_linter/src/checkers/tokens.rs

@@ -58,7 +58,7 @@ pub(crate) fn check_tokens(
     }
 
     if context.is_rule_enabled(Rule::EmptyComment) {
-        pylint::rules::empty_comments(context, comment_ranges, locator);
+        pylint::rules::empty_comments(context, comment_ranges, locator, indexer);
     }
 
     if context.is_rule_enabled(Rule::AmbiguousUnicodeCharacterComment) {

crates/ruff_linter/src/codes.rs

@@ -920,15 +920,15 @@ pub fn code_to_rule(linter: Linter, code: &str) -> Option<(RuleGroup, Rule)> {
 
         // flake8-use-pathlib
         (Flake8UsePathlib, "100") => (RuleGroup::Stable, rules::flake8_use_pathlib::rules::OsPathAbspath),
-        (Flake8UsePathlib, "101") => (RuleGroup::Stable, rules::flake8_use_pathlib::violations::OsChmod),
+        (Flake8UsePathlib, "101") => (RuleGroup::Stable, rules::flake8_use_pathlib::rules::OsChmod),
         (Flake8UsePathlib, "102") => (RuleGroup::Stable, rules::flake8_use_pathlib::violations::OsMkdir),
         (Flake8UsePathlib, "103") => (RuleGroup::Stable, rules::flake8_use_pathlib::violations::OsMakedirs),
-        (Flake8UsePathlib, "104") => (RuleGroup::Stable, rules::flake8_use_pathlib::violations::OsRename),
-        (Flake8UsePathlib, "105") => (RuleGroup::Stable, rules::flake8_use_pathlib::violations::OsReplace),
+        (Flake8UsePathlib, "104") => (RuleGroup::Stable, rules::flake8_use_pathlib::rules::OsRename),
+        (Flake8UsePathlib, "105") => (RuleGroup::Stable, rules::flake8_use_pathlib::rules::OsReplace),
         (Flake8UsePathlib, "106") => (RuleGroup::Stable, rules::flake8_use_pathlib::rules::OsRmdir),
         (Flake8UsePathlib, "107") => (RuleGroup::Stable, rules::flake8_use_pathlib::rules::OsRemove),
         (Flake8UsePathlib, "108") => (RuleGroup::Stable, rules::flake8_use_pathlib::rules::OsUnlink),
-        (Flake8UsePathlib, "109") => (RuleGroup::Stable, rules::flake8_use_pathlib::violations::OsGetcwd),
+        (Flake8UsePathlib, "109") => (RuleGroup::Stable, rules::flake8_use_pathlib::rules::OsGetcwd),
         (Flake8UsePathlib, "110") => (RuleGroup::Stable, rules::flake8_use_pathlib::rules::OsPathExists),
         (Flake8UsePathlib, "111") => (RuleGroup::Stable, rules::flake8_use_pathlib::rules::OsPathExpanduser),
         (Flake8UsePathlib, "112") => (RuleGroup::Stable, rules::flake8_use_pathlib::rules::OsPathIsdir),
@@ -940,7 +940,7 @@ pub fn code_to_rule(linter: Linter, code: &str) -> Option<(RuleGroup, Rule)> {
         (Flake8UsePathlib, "118") => (RuleGroup::Stable, rules::flake8_use_pathlib::violations::OsPathJoin),
         (Flake8UsePathlib, "119") => (RuleGroup::Stable, rules::flake8_use_pathlib::rules::OsPathBasename),
         (Flake8UsePathlib, "120") => (RuleGroup::Stable, rules::flake8_use_pathlib::rules::OsPathDirname),
-        (Flake8UsePathlib, "121") => (RuleGroup::Stable, rules::flake8_use_pathlib::violations::OsPathSamefile),
+        (Flake8UsePathlib, "121") => (RuleGroup::Stable, rules::flake8_use_pathlib::rules::OsPathSamefile),
         (Flake8UsePathlib, "122") => (RuleGroup::Stable, rules::flake8_use_pathlib::violations::OsPathSplitext),
         (Flake8UsePathlib, "123") => (RuleGroup::Stable, rules::flake8_use_pathlib::violations::BuiltinOpen),
         (Flake8UsePathlib, "124") => (RuleGroup::Stable, rules::flake8_use_pathlib::violations::PyPath),

crates/ruff_linter/src/importer/insertion.rs

@@ -288,7 +288,7 @@ fn match_docstring_end(body: &[Stmt]) -> Option<TextSize> {
 fn match_semicolon(s: &str) -> Option<TextSize> {
     for (offset, c) in s.char_indices() {
         match c {
-            ' ' | '\t' => continue,
+            _ if is_python_whitespace(c) => continue,
             ';' => return Some(TextSize::try_from(offset).unwrap()),
             _ => break,
         }

crates/ruff_linter/src/importer/mod.rs

@@ -527,6 +527,17 @@ impl<'a> Importer<'a> {
             None
         }
     }
+
+    /// Add a `from __future__ import annotations` import.
+    pub(crate) fn add_future_import(&self) -> Edit {
+        let import = &NameImport::ImportFrom(MemberNameImport::member(
+            "__future__".to_string(),
+            "annotations".to_string(),
+        ));
+        // Note that `TextSize::default` should ensure that the import is added at the very
+        // beginning of the file via `Insertion::start_of_file`.
+        self.add_import(import, TextSize::default())
+    }
 }
 
 /// An edit to the top-level of a module, making it available at runtime.

crates/ruff_linter/src/message/junit.rs

@@ -1,117 +0,0 @@
-use std::io::Write;
-use std::path::Path;
-
-use quick_junit::{NonSuccessKind, Report, TestCase, TestCaseStatus, TestSuite, XmlString};
-
-use ruff_db::diagnostic::Diagnostic;
-use ruff_source_file::LineColumn;
-
-use crate::message::{Emitter, EmitterContext, MessageWithLocation, group_diagnostics_by_filename};
-
-#[derive(Default)]
-pub struct JunitEmitter;
-
-impl Emitter for JunitEmitter {
-    fn emit(
-        &mut self,
-        writer: &mut dyn Write,
-        diagnostics: &[Diagnostic],
-        context: &EmitterContext,
-    ) -> anyhow::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, messages) in group_diagnostics_by_filename(diagnostics) {
-                let mut test_suite = TestSuite::new(&filename);
-                test_suite
-                    .extra
-                    .insert(XmlString::new("package"), XmlString::new("org.ruff"));
-
-                for message in messages {
-                    let MessageWithLocation {
-                        message,
-                        start_location,
-                    } = message;
-                    let mut status = TestCaseStatus::non_success(NonSuccessKind::Failure);
-                    status.set_message(message.body());
-                    let location = if context.is_notebook(&message.expect_ruff_filename()) {
-                        // We can't give a reasonable location for the structured formats,
-                        // so we show one that's clearly a fallback
-                        LineColumn::default()
-                    } else {
-                        start_location
-                    };
-
-                    status.set_description(format!(
-                        "line {row}, col {col}, {body}",
-                        row = location.line,
-                        col = location.column,
-                        body = message.body()
-                    ));
-                    let mut case = TestCase::new(
-                        if let Some(code) = message.secondary_code() {
-                            format!("org.ruff.{code}")
-                        } else {
-                            "org.ruff".to_string()
-                        },
-                        status,
-                    );
-                    let file_path = Path::new(&*filename);
-                    let file_stem = file_path.file_stem().unwrap().to_str().unwrap();
-                    let classname = file_path.parent().unwrap().join(file_stem);
-                    case.set_classname(classname.to_str().unwrap());
-                    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);
-            }
-        }
-
-        report.serialize(writer)?;
-
-        Ok(())
-    }
-}
-
-#[cfg(test)]
-mod tests {
-    use insta::assert_snapshot;
-
-    use crate::message::JunitEmitter;
-    use crate::message::tests::{
-        capture_emitter_output, create_diagnostics, create_syntax_error_diagnostics,
-    };
-
-    #[test]
-    fn output() {
-        let mut emitter = JunitEmitter;
-        let content = capture_emitter_output(&mut emitter, &create_diagnostics());
-
-        assert_snapshot!(content);
-    }
-
-    #[test]
-    fn syntax_errors() {
-        let mut emitter = JunitEmitter;
-        let content = capture_emitter_output(&mut emitter, &create_syntax_error_diagnostics());
-
-        assert_snapshot!(content);
-    }
-}

crates/ruff_linter/src/message/mod.rs

@@ -14,7 +14,6 @@ use ruff_db::files::File;
 pub use github::GithubEmitter;
 pub use gitlab::GitlabEmitter;
 pub use grouped::GroupedEmitter;
-pub use junit::JunitEmitter;
 use ruff_notebook::NotebookIndex;
 use ruff_source_file::{LineColumn, SourceFile};
 use ruff_text_size::{Ranged, TextRange, TextSize};
@@ -28,7 +27,6 @@ mod diff;
 mod github;
 mod gitlab;
 mod grouped;
-mod junit;
 mod sarif;
 mod text;
 
@@ -77,12 +75,13 @@ where
     );
 
     let span = Span::from(file).with_range(range);
-    let mut annotation = Annotation::primary(span);
-    if let Some(suggestion) = suggestion {
-        annotation = annotation.message(suggestion);
-    }
+    let annotation = Annotation::primary(span);
     diagnostic.annotate(annotation);
 
+    if let Some(suggestion) = suggestion {
+        diagnostic.help(suggestion);
+    }
+
     if let Some(fix) = fix {
         diagnostic.set_fix(fix);
     }

crates/ruff_linter/src/message/text.rs

@@ -6,13 +6,12 @@ use bitflags::bitflags;
 use colored::Colorize;
 use ruff_annotate_snippets::{Level, Renderer, Snippet};
 
-use ruff_db::diagnostic::{Diagnostic, SecondaryCode};
+use ruff_db::diagnostic::{Diagnostic, DiagnosticFormat, DisplayDiagnosticConfig, SecondaryCode};
 use ruff_notebook::NotebookIndex;
-use ruff_source_file::{LineColumn, OneIndexed};
+use ruff_source_file::OneIndexed;
 use ruff_text_size::{TextLen, TextRange, TextSize};
 
 use crate::Locator;
-use crate::fs::relativize_path;
 use crate::line_width::{IndentWidth, LineWidthBuilder};
 use crate::message::diff::Diff;
 use crate::message::{Emitter, EmitterContext};
@@ -21,8 +20,6 @@ use crate::settings::types::UnsafeFixes;
 bitflags! {
     #[derive(Default)]
     struct EmitterFlags: u8 {
-        /// Whether to show the fix status of a diagnostic.
-        const SHOW_FIX_STATUS   = 1 << 0;
         /// Whether to show the diff of a fix, for diagnostics that have a fix.
         const SHOW_FIX_DIFF     = 1 << 1;
         /// Whether to show the source code of a diagnostic.
@@ -30,17 +27,27 @@ bitflags! {
     }
 }
 
-#[derive(Default)]
 pub struct TextEmitter {
     flags: EmitterFlags,
-    unsafe_fixes: UnsafeFixes,
+    config: DisplayDiagnosticConfig,
+}
+
+impl Default for TextEmitter {
+    fn default() -> Self {
+        Self {
+            flags: EmitterFlags::default(),
+            config: DisplayDiagnosticConfig::default()
+                .format(DiagnosticFormat::Concise)
+                .hide_severity(true)
+                .color(!cfg!(test) && colored::control::SHOULD_COLORIZE.should_colorize()),
+        }
+    }
 }
 
 impl TextEmitter {
     #[must_use]
     pub fn with_show_fix_status(mut self, show_fix_status: bool) -> Self {
-        self.flags
-            .set(EmitterFlags::SHOW_FIX_STATUS, show_fix_status);
+        self.config = self.config.show_fix_status(show_fix_status);
         self
     }
 
@@ -58,7 +65,15 @@ impl TextEmitter {
 
     #[must_use]
     pub fn with_unsafe_fixes(mut self, unsafe_fixes: UnsafeFixes) -> Self {
-        self.unsafe_fixes = unsafe_fixes;
+        self.config = self
+            .config
+            .fix_applicability(unsafe_fixes.required_applicability());
+        self
+    }
+
+    #[must_use]
+    pub fn with_preview(mut self, preview: bool) -> Self {
+        self.config = self.config.preview(preview);
         self
     }
 }
@@ -71,51 +86,10 @@ impl Emitter for TextEmitter {
         context: &EmitterContext,
     ) -> anyhow::Result<()> {
         for message in diagnostics {
+            write!(writer, "{}", message.display(context, &self.config))?;
+
             let filename = message.expect_ruff_filename();
-            write!(
-                writer,
-                "{path}{sep}",
-                path = relativize_path(&filename).bold(),
-                sep = ":".cyan(),
-            )?;
-
-            let start_location = message.expect_ruff_start_location();
             let notebook_index = context.notebook_index(&filename);
-
-            // Check if we're working on a jupyter notebook and translate positions with cell accordingly
-            let diagnostic_location = if let Some(notebook_index) = notebook_index {
-                write!(
-                    writer,
-                    "cell {cell}{sep}",
-                    cell = notebook_index
-                        .cell(start_location.line)
-                        .unwrap_or(OneIndexed::MIN),
-                    sep = ":".cyan(),
-                )?;
-
-                LineColumn {
-                    line: notebook_index
-                        .cell_row(start_location.line)
-                        .unwrap_or(OneIndexed::MIN),
-                    column: start_location.column,
-                }
-            } else {
-                start_location
-            };
-
-            writeln!(
-                writer,
-                "{row}{sep}{col}{sep} {code_and_body}",
-                row = diagnostic_location.line,
-                col = diagnostic_location.column,
-                sep = ":".cyan(),
-                code_and_body = RuleCodeAndBody {
-                    message,
-                    show_fix_status: self.flags.intersects(EmitterFlags::SHOW_FIX_STATUS),
-                    unsafe_fixes: self.unsafe_fixes,
-                }
-            )?;
-
             if self.flags.intersects(EmitterFlags::SHOW_SOURCE) {
                 // The `0..0` range is used to highlight file-level diagnostics.
                 if message.expect_range() != TextRange::default() {
@@ -186,7 +160,7 @@ pub(super) struct MessageCodeFrame<'a> {
 
 impl Display for MessageCodeFrame<'_> {
     fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
-        let suggestion = self.message.suggestion();
+        let suggestion = self.message.first_help_text();
         let footers = if let Some(suggestion) = suggestion {
             vec![Level::Help.title(suggestion)]
         } else {

crates/ruff_linter/src/preview.rs

@@ -134,6 +134,31 @@ pub(crate) const fn is_fix_os_path_dirname_enabled(settings: &LinterSettings) ->
     settings.preview.is_enabled()
 }
 
+// https://github.com/astral-sh/ruff/pull/19404
+pub(crate) const fn is_fix_os_chmod_enabled(settings: &LinterSettings) -> bool {
+    settings.preview.is_enabled()
+}
+
+// https://github.com/astral-sh/ruff/pull/19404
+pub(crate) const fn is_fix_os_rename_enabled(settings: &LinterSettings) -> bool {
+    settings.preview.is_enabled()
+}
+
+// https://github.com/astral-sh/ruff/pull/19404
+pub(crate) const fn is_fix_os_replace_enabled(settings: &LinterSettings) -> bool {
+    settings.preview.is_enabled()
+}
+
+// https://github.com/astral-sh/ruff/pull/19404
+pub(crate) const fn is_fix_os_path_samefile_enabled(settings: &LinterSettings) -> bool {
+    settings.preview.is_enabled()
+}
+
+// https://github.com/astral-sh/ruff/pull/19245
+pub(crate) const fn is_fix_os_getcwd_enabled(settings: &LinterSettings) -> bool {
+    settings.preview.is_enabled()
+}
+
 // https://github.com/astral-sh/ruff/pull/11436
 // https://github.com/astral-sh/ruff/pull/11168
 pub(crate) const fn is_dunder_init_fix_unused_import_enabled(settings: &LinterSettings) -> bool {
@@ -195,3 +220,8 @@ pub(crate) const fn is_safe_super_call_with_parameters_fix_enabled(
 pub(crate) const fn is_assert_raises_exception_call_enabled(settings: &LinterSettings) -> bool {
     settings.preview.is_enabled()
 }
+
+// https://github.com/astral-sh/ruff/pull/19100
+pub(crate) const fn is_add_future_annotations_imports_enabled(settings: &LinterSettings) -> bool {
+    settings.preview.is_enabled()
+}

crates/ruff_linter/src/rules/flake8_future_annotations/rules/future_required_type_annotation.rs

@@ -2,8 +2,7 @@ use std::fmt;
 
 use ruff_macros::{ViolationMetadata, derive_message_formats};
 use ruff_python_ast::Expr;
-use ruff_python_semantic::{MemberNameImport, NameImport};
-use ruff_text_size::{Ranged, TextSize};
+use ruff_text_size::Ranged;
 
 use crate::checkers::ast::Checker;
 use crate::{AlwaysFixableViolation, Fix};
@@ -85,15 +84,7 @@ impl AlwaysFixableViolation for FutureRequiredTypeAnnotation {
 
 /// FA102
 pub(crate) fn future_required_type_annotation(checker: &Checker, expr: &Expr, reason: Reason) {
-    let mut diagnostic =
-        checker.report_diagnostic(FutureRequiredTypeAnnotation { reason }, expr.range());
-    let required_import = NameImport::ImportFrom(MemberNameImport::member(
-        "__future__".to_string(),
-        "annotations".to_string(),
-    ));
-    diagnostic.set_fix(Fix::unsafe_edit(
-        checker
-            .importer()
-            .add_import(&required_import, TextSize::default()),
-    ));
+    checker
+        .report_diagnostic(FutureRequiredTypeAnnotation { reason }, expr.range())
+        .set_fix(Fix::unsafe_edit(checker.importer().add_future_import()));
 }

crates/ruff_linter/src/rules/flake8_future_annotations/rules/future_rewritable_type_annotation.rs

@@ -1,12 +1,10 @@
-use ruff_diagnostics::Fix;
 use ruff_python_ast::Expr;
 
 use ruff_macros::{ViolationMetadata, derive_message_formats};
-use ruff_python_semantic::{MemberNameImport, NameImport};
 use ruff_text_size::Ranged;
 
-use crate::AlwaysFixableViolation;
 use crate::checkers::ast::Checker;
+use crate::{AlwaysFixableViolation, Fix};
 
 /// ## What it does
 /// Checks for missing `from __future__ import annotations` imports upon
@@ -95,15 +93,7 @@ pub(crate) fn future_rewritable_type_annotation(checker: &Checker, expr: &Expr)
 
     let Some(name) = name else { return };
 
-    let import = &NameImport::ImportFrom(MemberNameImport::member(
-        "__future__".to_string(),
-        "annotations".to_string(),
-    ));
     checker
         .report_diagnostic(FutureRewritableTypeAnnotation { name }, expr.range())
-        .set_fix(Fix::unsafe_edit(
-            checker
-                .importer()
-                .add_import(import, ruff_text_size::TextSize::default()),
-        ));
+        .set_fix(Fix::unsafe_edit(checker.importer().add_future_import()));
 }

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

@@ -64,6 +64,7 @@ pub(crate) fn duplicate_union_member<'a>(checker: &Checker, expr: &'a Expr) {
     let mut diagnostics = Vec::new();
 
     let mut union_type = UnionKind::TypingUnion;
+    let mut optional_present = false;
     // Adds a member to `literal_exprs` if it is a `Literal` annotation
     let mut check_for_duplicate_members = |expr: &'a Expr, parent: &'a Expr| {
         if matches!(parent, Expr::BinOp(_)) {
@@ -74,6 +75,7 @@ pub(crate) fn duplicate_union_member<'a>(checker: &Checker, expr: &'a Expr) {
             && is_optional_type(checker, expr)
         {
             // If the union member is an `Optional`, add a virtual `None` literal.
+            optional_present = true;
             &VIRTUAL_NONE_LITERAL
         } else {
             expr
@@ -87,7 +89,7 @@ pub(crate) fn duplicate_union_member<'a>(checker: &Checker, expr: &'a Expr) {
                 DuplicateUnionMember {
                     duplicate_name: checker.generator().expr(virtual_expr),
                 },
-                // Use the real expression's range for diagnostics,
+                // Use the real expression's range for diagnostics.
                 expr.range(),
             ));
         }
@@ -104,6 +106,13 @@ pub(crate) fn duplicate_union_member<'a>(checker: &Checker, expr: &'a Expr) {
         return;
     }
 
+    // Do not reduce `Union[None, ... None]` to avoid introducing a `TypeError` unintentionally
+    // e.g. `isinstance(None, Union[None, None])`, if reduced to `isinstance(None, None)`, causes
+    // `TypeError: isinstance() arg 2 must be a type, a tuple of types, or a union` to throw.
+    if unique_nodes.iter().all(|expr| expr.is_none_literal_expr()) && !optional_present {
+        return;
+    }
+
     // Mark [`Fix`] as unsafe when comments are in range.
     let applicability = if checker.comment_ranges().intersects(expr.range()) {
         Applicability::Unsafe

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

@@ -974,6 +974,8 @@ PYI016.py:143:61: PYI016 [*] Duplicate union member `complex`
 143     |-field48: typing.Union[typing.Optional[typing.Union[complex, complex]], complex]
     143 |+field48: typing.Union[typing.Optional[complex], complex]
 144 144 | field49: typing.Optional[complex | complex] | complex
+145 145 | 
+146 146 | # Regression test for https://github.com/astral-sh/ruff/issues/19403
 
 PYI016.py:144:36: PYI016 [*] Duplicate union member `complex`
     |
@@ -981,6 +983,8 @@ PYI016.py:144:36: PYI016 [*] Duplicate union member `complex`
 143 | field48: typing.Union[typing.Optional[typing.Union[complex, complex]], complex]
 144 | field49: typing.Optional[complex | complex] | complex
     |                                    ^^^^^^^ PYI016
+145 |
+146 | # Regression test for https://github.com/astral-sh/ruff/issues/19403
     |
     = help: Remove duplicate union member `complex`
 
@@ -990,3 +994,15 @@ PYI016.py:144:36: PYI016 [*] Duplicate union member `complex`
 143 143 | field48: typing.Union[typing.Optional[typing.Union[complex, complex]], complex]
 144     |-field49: typing.Optional[complex | complex] | complex
     144 |+field49: typing.Optional[complex] | complex
+145 145 | 
+146 146 | # Regression test for https://github.com/astral-sh/ruff/issues/19403
+147 147 | # Should throw duplicate union member but not fix
+
+PYI016.py:148:37: PYI016 Duplicate union member `None`
+    |
+146 | # Regression test for https://github.com/astral-sh/ruff/issues/19403
+147 | # Should throw duplicate union member but not fix
+148 | isinstance(None, typing.Union[None, None])
+    |                                     ^^^^ PYI016
+    |
+    = help: Remove duplicate union member `None`

crates/ruff_linter/src/rules/flake8_pyi/snapshots/ruff_linter__rules__flake8_pyi__tests__preview__PYI016_PYI016.py.snap

@@ -1162,6 +1162,8 @@ PYI016.py:143:61: PYI016 [*] Duplicate union member `complex`
 143     |-field48: typing.Union[typing.Optional[typing.Union[complex, complex]], complex]
     143 |+field48: typing.Union[None, complex]
 144 144 | field49: typing.Optional[complex | complex] | complex
+145 145 | 
+146 146 | # Regression test for https://github.com/astral-sh/ruff/issues/19403
 
 PYI016.py:143:72: PYI016 [*] Duplicate union member `complex`
     |
@@ -1179,6 +1181,8 @@ PYI016.py:143:72: PYI016 [*] Duplicate union member `complex`
 143     |-field48: typing.Union[typing.Optional[typing.Union[complex, complex]], complex]
     143 |+field48: typing.Union[None, complex]
 144 144 | field49: typing.Optional[complex | complex] | complex
+145 145 | 
+146 146 | # Regression test for https://github.com/astral-sh/ruff/issues/19403
 
 PYI016.py:144:36: PYI016 [*] Duplicate union member `complex`
     |
@@ -1186,6 +1190,8 @@ PYI016.py:144:36: PYI016 [*] Duplicate union member `complex`
 143 | field48: typing.Union[typing.Optional[typing.Union[complex, complex]], complex]
 144 | field49: typing.Optional[complex | complex] | complex
     |                                    ^^^^^^^ PYI016
+145 |
+146 | # Regression test for https://github.com/astral-sh/ruff/issues/19403
     |
     = help: Remove duplicate union member `complex`
 
@@ -1195,6 +1201,9 @@ PYI016.py:144:36: PYI016 [*] Duplicate union member `complex`
 143 143 | field48: typing.Union[typing.Optional[typing.Union[complex, complex]], complex]
 144     |-field49: typing.Optional[complex | complex] | complex
     144 |+field49: None | complex
+145 145 | 
+146 146 | # Regression test for https://github.com/astral-sh/ruff/issues/19403
+147 147 | # Should throw duplicate union member but not fix
 
 PYI016.py:144:47: PYI016 [*] Duplicate union member `complex`
     |
@@ -1202,6 +1211,8 @@ PYI016.py:144:47: PYI016 [*] Duplicate union member `complex`
 143 | field48: typing.Union[typing.Optional[typing.Union[complex, complex]], complex]
 144 | field49: typing.Optional[complex | complex] | complex
     |                                               ^^^^^^^ PYI016
+145 |
+146 | # Regression test for https://github.com/astral-sh/ruff/issues/19403
     |
     = help: Remove duplicate union member `complex`
 
@@ -1211,3 +1222,15 @@ PYI016.py:144:47: PYI016 [*] Duplicate union member `complex`
 143 143 | field48: typing.Union[typing.Optional[typing.Union[complex, complex]], complex]
 144     |-field49: typing.Optional[complex | complex] | complex
     144 |+field49: None | complex
+145 145 | 
+146 146 | # Regression test for https://github.com/astral-sh/ruff/issues/19403
+147 147 | # Should throw duplicate union member but not fix
+
+PYI016.py:148:37: PYI016 Duplicate union member `None`
+    |
+146 | # Regression test for https://github.com/astral-sh/ruff/issues/19403
+147 | # Should throw duplicate union member but not fix
+148 | isinstance(None, typing.Union[None, None])
+    |                                     ^^^^ PYI016
+    |
+    = help: Remove duplicate union member `None`

crates/ruff_linter/src/rules/flake8_type_checking/helpers.rs

@@ -8,41 +8,110 @@ use ruff_python_ast::{self as ast, Decorator, Expr, StringLiteralFlags};
 use ruff_python_codegen::{Generator, Stylist};
 use ruff_python_parser::typing::parse_type_annotation;
 use ruff_python_semantic::{
-    Binding, BindingKind, Modules, NodeId, ResolvedReference, ScopeKind, SemanticModel, analyze,
+    Binding, BindingKind, Modules, NodeId, ScopeKind, SemanticModel, analyze,
 };
 use ruff_text_size::{Ranged, TextRange};
 
 use crate::Edit;
 use crate::Locator;
-use crate::rules::flake8_type_checking::settings::Settings;
+use crate::settings::LinterSettings;
 
-/// Returns `true` if the [`ResolvedReference`] is in a typing-only context _or_ a runtime-evaluated
-/// context (with quoting enabled).
-pub(crate) fn is_typing_reference(reference: &ResolvedReference, settings: &Settings) -> bool {
-    reference.in_type_checking_block()
-        // if we're not in a type checking block, we necessarily need to be within a
-        // type definition to be considered a typing reference
-        || (reference.in_type_definition()
-            && (reference.in_typing_only_annotation()
-                || reference.in_string_type_definition()
-                || (settings.quote_annotations && reference.in_runtime_evaluated_annotation())))
+/// Represents the kind of an existing or potential typing-only annotation.
+///
+/// Note that the order of variants is important here. `Runtime` has the highest precedence when
+/// calling [`TypingReference::combine`] on two references, followed by `Future`, `Quote`, and
+/// `TypingOnly` with the lowest precedence.
+#[derive(Clone, Copy, Debug, PartialEq, Eq, PartialOrd, Ord)]
+pub(crate) enum TypingReference {
+    /// The reference is in a runtime-evaluated context.
+    Runtime,
+    /// The reference is in a runtime-evaluated context, but the
+    /// `lint.future-annotations` setting is enabled.
+    ///
+    /// This takes precedence if both quoting and future imports are enabled.
+    Future,
+    /// The reference is in a runtime-evaluated context, but the
+    /// `lint.flake8-type-checking.quote-annotations` setting is enabled.
+    Quote,
+    /// The reference is in a typing-only context.
+    TypingOnly,
+}
+
+impl TypingReference {
+    /// Determine the kind of [`TypingReference`] for all references to a binding.
+    pub(crate) fn from_references(
+        binding: &Binding,
+        semantic: &SemanticModel,
+        settings: &LinterSettings,
+    ) -> Self {
+        let references = binding
+            .references()
+            .map(|reference_id| semantic.reference(reference_id));
+        let mut kind = Self::TypingOnly;
+        for reference in references {
+            if reference.in_type_checking_block() {
+                kind = kind.combine(Self::TypingOnly);
+                continue;
+            }
+
+            // if we're not in a type checking block, we necessarily need to be within a
+            // type definition to be considered a typing reference
+            if !reference.in_type_definition() {
+                return Self::Runtime;
+            }
+
+            if reference.in_typing_only_annotation() || reference.in_string_type_definition() {
+                kind = kind.combine(Self::TypingOnly);
+                continue;
+            }
+
+            // prefer `from __future__ import annotations` to quoting
+            if settings.future_annotations()
+                && !reference.in_typing_only_annotation()
+                && reference.in_runtime_evaluated_annotation()
+            {
+                kind = kind.combine(Self::Future);
+                continue;
+            }
+
+            if settings.flake8_type_checking.quote_annotations
+                && reference.in_runtime_evaluated_annotation()
+            {
+                kind = kind.combine(Self::Quote);
+                continue;
+            }
+
+            return Self::Runtime;
+        }
+
+        kind
+    }
+
+    /// Logically combine two `TypingReference`s into one.
+    ///
+    /// `TypingReference::Runtime` has the highest precedence, followed by
+    /// `TypingReference::Future`, `TypingReference::Quote`, and then `TypingReference::TypingOnly`.
+    fn combine(self, other: TypingReference) -> TypingReference {
+        self.min(other)
+    }
+
+    fn is_runtime(self) -> bool {
+        matches!(self, Self::Runtime)
+    }
 }
 
 /// Returns `true` if the [`Binding`] represents a runtime-required import.
 pub(crate) fn is_valid_runtime_import(
     binding: &Binding,
     semantic: &SemanticModel,
-    settings: &Settings,
+    settings: &LinterSettings,
 ) -> bool {
     if matches!(
         binding.kind,
         BindingKind::Import(..) | BindingKind::FromImport(..) | BindingKind::SubmoduleImport(..)
     ) {
         binding.context.is_runtime()
-            && binding
-                .references()
-                .map(|reference_id| semantic.reference(reference_id))
-                .any(|reference| !is_typing_reference(reference, settings))
+            && TypingReference::from_references(binding, semantic, settings).is_runtime()
     } else {
         false
     }

crates/ruff_linter/src/rules/flake8_type_checking/imports.rs

@@ -13,6 +13,8 @@ pub(crate) struct ImportBinding<'a> {
     pub(crate) range: TextRange,
     /// The range of the import's parent statement.
     pub(crate) parent_range: Option<TextRange>,
+    /// Whether the binding needs `from __future__ import annotations` to be imported.
+    pub(crate) needs_future_import: bool,
 }
 
 impl Ranged for ImportBinding<'_> {

crates/ruff_linter/src/rules/flake8_type_checking/mod.rs

@@ -9,10 +9,12 @@ mod tests {
     use std::path::Path;
 
     use anyhow::Result;
+    use itertools::Itertools;
     use ruff_python_ast::PythonVersion;
     use test_case::test_case;
 
     use crate::registry::{Linter, Rule};
+    use crate::settings::types::PreviewMode;
     use crate::test::{test_path, test_snippet};
     use crate::{assert_diagnostics, settings};
 
@@ -64,6 +66,40 @@ mod tests {
         Ok(())
     }
 
+    #[test_case(&[Rule::TypingOnlyFirstPartyImport], Path::new("TC001.py"))]
+    #[test_case(&[Rule::TypingOnlyThirdPartyImport], Path::new("TC002.py"))]
+    #[test_case(&[Rule::TypingOnlyStandardLibraryImport], Path::new("TC003.py"))]
+    #[test_case(
+        &[
+            Rule::TypingOnlyFirstPartyImport,
+            Rule::TypingOnlyThirdPartyImport,
+            Rule::TypingOnlyStandardLibraryImport,
+        ],
+        Path::new("TC001-3_future.py")
+    )]
+    #[test_case(&[Rule::TypingOnlyFirstPartyImport], Path::new("TC001_future.py"))]
+    #[test_case(&[Rule::TypingOnlyFirstPartyImport], Path::new("TC001_future_present.py"))]
+    fn add_future_import(rules: &[Rule], path: &Path) -> Result<()> {
+        let name = rules.iter().map(Rule::noqa_code).join("-");
+        let snapshot = format!("add_future_import__{}_{}", name, path.to_string_lossy());
+        let diagnostics = test_path(
+            Path::new("flake8_type_checking").join(path).as_path(),
+            &settings::LinterSettings {
+                future_annotations: true,
+                preview: PreviewMode::Enabled,
+                // also enable quoting annotations to check the interaction. the future import
+                // should take precedence.
+                flake8_type_checking: super::settings::Settings {
+                    quote_annotations: true,
+                    ..Default::default()
+                },
+                ..settings::LinterSettings::for_rules(rules.iter().copied())
+            },
+        )?;
+        assert_diagnostics!(snapshot, diagnostics);
+        Ok(())
+    }
+
     // we test these rules as a pair, since they're opposites of one another
     // so we want to make sure their fixes are not going around in circles.
     #[test_case(Rule::UnquotedTypeAlias, Path::new("TC007.py"))]

crates/ruff_linter/src/rules/flake8_type_checking/rules/runtime_import_in_type_checking_block.rs

@@ -139,6 +139,7 @@ pub(crate) fn runtime_import_in_type_checking_block(checker: &Checker, scope: &S
                 binding,
                 range: binding.range(),
                 parent_range: binding.parent_range(checker.semantic()),
+                needs_future_import: false, // TODO(brent) See #19359.
             };
 
             if checker.rule_is_ignored(Rule::RuntimeImportInTypeCheckingBlock, import.start())

crates/ruff_linter/src/rules/flake8_type_checking/rules/typing_only_runtime_import.rs

@@ -13,7 +13,7 @@ use crate::fix;
 use crate::importer::ImportedMembers;
 use crate::preview::is_full_path_match_source_strategy_enabled;
 use crate::rules::flake8_type_checking::helpers::{
-    filter_contained, is_typing_reference, quote_annotation,
+    TypingReference, filter_contained, quote_annotation,
 };
 use crate::rules::flake8_type_checking::imports::ImportBinding;
 use crate::rules::isort::categorize::MatchSourceStrategy;
@@ -71,12 +71,19 @@ use crate::{Fix, FixAvailability, Violation};
 /// the criterion for determining whether an import is first-party
 /// is stricter, which could affect whether this lint is triggered vs [`TC001`](https://docs.astral.sh/ruff/rules/typing-only-third-party-import/). 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.
 ///
+/// If [`lint.future-annotations`] is set to `true`, `from __future__ import
+/// annotations` will be added if doing so would enable an import to be moved into an `if
+/// TYPE_CHECKING:` block. This takes precedence over the
+/// [`lint.flake8-type-checking.quote-annotations`] setting described above if both settings are
+/// enabled.
+///
 /// ## Options
 /// - `lint.flake8-type-checking.quote-annotations`
 /// - `lint.flake8-type-checking.runtime-evaluated-base-classes`
 /// - `lint.flake8-type-checking.runtime-evaluated-decorators`
 /// - `lint.flake8-type-checking.strict`
 /// - `lint.typing-modules`
+/// - `lint.future-annotations`
 ///
 /// ## References
 /// - [PEP 563: Runtime annotation resolution and `TYPE_CHECKING`](https://peps.python.org/pep-0563/#runtime-annotation-resolution-and-type-checking)
@@ -151,12 +158,19 @@ impl Violation for TypingOnlyFirstPartyImport {
 /// the criterion for determining whether an import is first-party
 /// is stricter, which could affect whether this lint is triggered vs [`TC001`](https://docs.astral.sh/ruff/rules/typing-only-first-party-import/). 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.
 ///
+/// If [`lint.future-annotations`] is set to `true`, `from __future__ import
+/// annotations` will be added if doing so would enable an import to be moved into an `if
+/// TYPE_CHECKING:` block. This takes precedence over the
+/// [`lint.flake8-type-checking.quote-annotations`] setting described above if both settings are
+/// enabled.
+///
 /// ## Options
 /// - `lint.flake8-type-checking.quote-annotations`
 /// - `lint.flake8-type-checking.runtime-evaluated-base-classes`
 /// - `lint.flake8-type-checking.runtime-evaluated-decorators`
 /// - `lint.flake8-type-checking.strict`
 /// - `lint.typing-modules`
+/// - `lint.future-annotations`
 ///
 /// ## References
 /// - [PEP 563: Runtime annotation resolution and `TYPE_CHECKING`](https://peps.python.org/pep-0563/#runtime-annotation-resolution-and-type-checking)
@@ -226,12 +240,22 @@ impl Violation for TypingOnlyThirdPartyImport {
 ///     return str(path)
 /// ```
 ///
+/// ## Preview
+///
+/// When [preview](https://docs.astral.sh/ruff/preview/) is enabled, if
+/// [`lint.future-annotations`] is set to `true`, `from __future__ import
+/// annotations` will be added if doing so would enable an import to be moved into an `if
+/// TYPE_CHECKING:` block. This takes precedence over the
+/// [`lint.flake8-type-checking.quote-annotations`] setting described above if both settings are
+/// enabled.
+///
 /// ## Options
 /// - `lint.flake8-type-checking.quote-annotations`
 /// - `lint.flake8-type-checking.runtime-evaluated-base-classes`
 /// - `lint.flake8-type-checking.runtime-evaluated-decorators`
 /// - `lint.flake8-type-checking.strict`
 /// - `lint.typing-modules`
+/// - `lint.future-annotations`
 ///
 /// ## References
 /// - [PEP 563: Runtime annotation resolution and `TYPE_CHECKING`](https://peps.python.org/pep-0563/#runtime-annotation-resolution-and-type-checking)
@@ -271,9 +295,10 @@ pub(crate) fn typing_only_runtime_import(
     for binding_id in scope.binding_ids() {
         let binding = checker.semantic().binding(binding_id);
 
-        // If we're in un-strict mode, don't flag typing-only imports that are
-        // implicitly loaded by way of a valid runtime import.
-        if !checker.settings().flake8_type_checking.strict
+        // If we can't add a `__future__` import and in un-strict mode, don't flag typing-only
+        // imports that are implicitly loaded by way of a valid runtime import.
+        if !checker.settings().future_annotations()
+            && !checker.settings().flake8_type_checking.strict
             && runtime_imports
                 .iter()
                 .any(|import| is_implicit_import(binding, import))
@@ -289,95 +314,102 @@ pub(crate) fn typing_only_runtime_import(
             continue;
         };
 
-        if binding.context.is_runtime()
-            && binding
-                .references()
-                .map(|reference_id| checker.semantic().reference(reference_id))
-                .all(|reference| {
-                    is_typing_reference(reference, &checker.settings().flake8_type_checking)
-                })
-        {
-            let qualified_name = import.qualified_name();
+        if !binding.context.is_runtime() {
+            continue;
+        }
 
-            if is_exempt(
-                &qualified_name.to_string(),
-                &checker
-                    .settings()
-                    .flake8_type_checking
-                    .exempt_modules
-                    .iter()
-                    .map(String::as_str)
-                    .collect::<Vec<_>>(),
-            ) {
-                continue;
-            }
+        let typing_reference =
+            TypingReference::from_references(binding, checker.semantic(), checker.settings());
 
-            let source_name = import.source_name().join(".");
+        let needs_future_import = match typing_reference {
+            TypingReference::Runtime => continue,
+            // We can only get the `Future` variant if `future_annotations` is
+            // enabled, so we can unconditionally set this here.
+            TypingReference::Future => true,
+            TypingReference::TypingOnly | TypingReference::Quote => false,
+        };
 
-            // Categorize the import, using coarse-grained categorization.
-            let match_source_strategy =
-                if is_full_path_match_source_strategy_enabled(checker.settings()) {
-                    MatchSourceStrategy::FullPath
-                } else {
-                    MatchSourceStrategy::Root
-                };
+        let qualified_name = import.qualified_name();
 
-            let import_type = match categorize(
-                &source_name,
-                qualified_name.is_unresolved_import(),
-                &checker.settings().src,
-                checker.package(),
-                checker.settings().isort.detect_same_package,
-                &checker.settings().isort.known_modules,
-                checker.target_version(),
-                checker.settings().isort.no_sections,
-                &checker.settings().isort.section_order,
-                &checker.settings().isort.default_section,
-                match_source_strategy,
-            ) {
-                ImportSection::Known(ImportType::LocalFolder | ImportType::FirstParty) => {
-                    ImportType::FirstParty
-                }
-                ImportSection::Known(ImportType::ThirdParty) | ImportSection::UserDefined(_) => {
-                    ImportType::ThirdParty
-                }
-                ImportSection::Known(ImportType::StandardLibrary) => ImportType::StandardLibrary,
-                ImportSection::Known(ImportType::Future) => {
-                    continue;
-                }
-            };
+        if is_exempt(
+            &qualified_name.to_string(),
+            &checker
+                .settings()
+                .flake8_type_checking
+                .exempt_modules
+                .iter()
+                .map(String::as_str)
+                .collect::<Vec<_>>(),
+        ) {
+            continue;
+        }
 
-            if !checker.is_rule_enabled(rule_for(import_type)) {
-                continue;
-            }
+        let source_name = import.source_name().join(".");
 
-            let Some(node_id) = binding.source else {
-                continue;
-            };
-
-            let import = ImportBinding {
-                import,
-                reference_id,
-                binding,
-                range: binding.range(),
-                parent_range: binding.parent_range(checker.semantic()),
-            };
-
-            if checker.rule_is_ignored(rule_for(import_type), import.start())
-                || import.parent_range.is_some_and(|parent_range| {
-                    checker.rule_is_ignored(rule_for(import_type), parent_range.start())
-                })
-            {
-                ignores_by_statement
-                    .entry((node_id, import_type))
-                    .or_default()
-                    .push(import);
+        // Categorize the import, using coarse-grained categorization.
+        let match_source_strategy =
+            if is_full_path_match_source_strategy_enabled(checker.settings()) {
+                MatchSourceStrategy::FullPath
             } else {
-                errors_by_statement
-                    .entry((node_id, import_type))
-                    .or_default()
-                    .push(import);
+                MatchSourceStrategy::Root
+            };
+
+        let import_type = match categorize(
+            &source_name,
+            qualified_name.is_unresolved_import(),
+            &checker.settings().src,
+            checker.package(),
+            checker.settings().isort.detect_same_package,
+            &checker.settings().isort.known_modules,
+            checker.target_version(),
+            checker.settings().isort.no_sections,
+            &checker.settings().isort.section_order,
+            &checker.settings().isort.default_section,
+            match_source_strategy,
+        ) {
+            ImportSection::Known(ImportType::LocalFolder | ImportType::FirstParty) => {
+                ImportType::FirstParty
             }
+            ImportSection::Known(ImportType::ThirdParty) | ImportSection::UserDefined(_) => {
+                ImportType::ThirdParty
+            }
+            ImportSection::Known(ImportType::StandardLibrary) => ImportType::StandardLibrary,
+            ImportSection::Known(ImportType::Future) => {
+                continue;
+            }
+        };
+
+        if !checker.is_rule_enabled(rule_for(import_type)) {
+            continue;
+        }
+
+        let Some(node_id) = binding.source else {
+            continue;
+        };
+
+        let import = ImportBinding {
+            import,
+            reference_id,
+            binding,
+            range: binding.range(),
+            parent_range: binding.parent_range(checker.semantic()),
+            needs_future_import,
+        };
+
+        if checker.rule_is_ignored(rule_for(import_type), import.start())
+            || import.parent_range.is_some_and(|parent_range| {
+                checker.rule_is_ignored(rule_for(import_type), parent_range.start())
+            })
+        {
+            ignores_by_statement
+                .entry((node_id, import_type))
+                .or_default()
+                .push(import);
+        } else {
+            errors_by_statement
+                .entry((node_id, import_type))
+                .or_default()
+                .push(import);
         }
     }
 
@@ -509,6 +541,8 @@ fn fix_imports(checker: &Checker, node_id: NodeId, imports: &[ImportBinding]) ->
         .min()
         .expect("Expected at least one import");
 
+    let add_future_import = imports.iter().any(|binding| binding.needs_future_import);
+
     // Step 1) Remove the import.
     let remove_import_edit = fix::edits::remove_unused_imports(
         member_names.iter().map(AsRef::as_ref),
@@ -532,37 +566,52 @@ fn fix_imports(checker: &Checker, node_id: NodeId, imports: &[ImportBinding]) ->
         )?
         .into_edits();
 
-    // Step 3) Quote any runtime usages of the referenced symbol.
-    let quote_reference_edits = filter_contained(
-        imports
-            .iter()
-            .flat_map(|ImportBinding { binding, .. }| {
-                binding.references.iter().filter_map(|reference_id| {
-                    let reference = checker.semantic().reference(*reference_id);
-                    if reference.in_runtime_context() {
-                        Some(quote_annotation(
-                            reference.expression_id()?,
-                            checker.semantic(),
-                            checker.stylist(),
-                            checker.locator(),
-                            checker.default_string_flags(),
-                        ))
-                    } else {
-                        None
-                    }
-                })
-            })
-            .collect::<Vec<_>>(),
-    );
+    // Step 3) Either add a `__future__` import or quote any runtime usages of the referenced
+    // symbol.
+    let fix = if add_future_import {
+        let future_import = checker.importer().add_future_import();
 
-    Ok(Fix::unsafe_edits(
-        type_checking_edit,
-        add_import_edit
-            .into_iter()
-            .chain(std::iter::once(remove_import_edit))
-            .chain(quote_reference_edits),
-    )
-    .isolate(Checker::isolation(
+        // The order here is very important. We first need to add the `__future__` import, if
+        // needed, since it's a syntax error to come later. Then `type_checking_edit` imports
+        // `TYPE_CHECKING`, if available. Then we can add and/or remove existing imports.
+        Fix::unsafe_edits(
+            future_import,
+            std::iter::once(type_checking_edit)
+                .chain(add_import_edit)
+                .chain(std::iter::once(remove_import_edit)),
+        )
+    } else {
+        let quote_reference_edits = filter_contained(
+            imports
+                .iter()
+                .flat_map(|ImportBinding { binding, .. }| {
+                    binding.references.iter().filter_map(|reference_id| {
+                        let reference = checker.semantic().reference(*reference_id);
+                        if reference.in_runtime_context() {
+                            Some(quote_annotation(
+                                reference.expression_id()?,
+                                checker.semantic(),
+                                checker.stylist(),
+                                checker.locator(),
+                                checker.default_string_flags(),
+                            ))
+                        } else {
+                            None
+                        }
+                    })
+                })
+                .collect::<Vec<_>>(),
+        );
+        Fix::unsafe_edits(
+            type_checking_edit,
+            add_import_edit
+                .into_iter()
+                .chain(std::iter::once(remove_import_edit))
+                .chain(quote_reference_edits),
+        )
+    };
+
+    Ok(fix.isolate(Checker::isolation(
         checker.semantic().parent_statement_id(node_id),
     )))
 }

crates/ruff_linter/src/rules/flake8_type_checking/snapshots/ruff_linter__rules__flake8_type_checking__tests__add_future_import__TC001-TC002-TC003_TC001-3_future.py.snap

@@ -0,0 +1,76 @@
+---
+source: crates/ruff_linter/src/rules/flake8_type_checking/mod.rs
+---
+TC001-3_future.py:1:25: TC003 [*] Move standard library import `collections.Counter` into a type-checking block
+  |
+1 | from collections import Counter
+  |                         ^^^^^^^ TC003
+2 |
+3 | from elsewhere import third_party
+  |
+  = help: Move into type-checking block
+
+ℹ Unsafe fix
+1     |-from collections import Counter
+   1  |+from __future__ import annotations
+2  2  | 
+3  3  | from elsewhere import third_party
+4  4  | 
+5  5  | from . import first_party
+   6  |+from typing import TYPE_CHECKING
+   7  |+
+   8  |+if TYPE_CHECKING:
+   9  |+    from collections import Counter
+6  10 | 
+7  11 | 
+8  12 | def f(x: first_party.foo): ...
+
+TC001-3_future.py:3:23: TC002 [*] Move third-party import `elsewhere.third_party` into a type-checking block
+  |
+1 | from collections import Counter
+2 |
+3 | from elsewhere import third_party
+  |                       ^^^^^^^^^^^ TC002
+4 |
+5 | from . import first_party
+  |
+  = help: Move into type-checking block
+
+ℹ Unsafe fix
+   1  |+from __future__ import annotations
+1  2  | from collections import Counter
+2  3  | 
+3     |-from elsewhere import third_party
+4  4  | 
+5  5  | from . import first_party
+   6  |+from typing import TYPE_CHECKING
+   7  |+
+   8  |+if TYPE_CHECKING:
+   9  |+    from elsewhere import third_party
+6  10 | 
+7  11 | 
+8  12 | def f(x: first_party.foo): ...
+
+TC001-3_future.py:5:15: TC001 [*] Move application import `.first_party` into a type-checking block
+  |
+3 | from elsewhere import third_party
+4 |
+5 | from . import first_party
+  |               ^^^^^^^^^^^ TC001
+  |
+  = help: Move into type-checking block
+
+ℹ Unsafe fix
+   1  |+from __future__ import annotations
+1  2  | from collections import Counter
+2  3  | 
+3  4  | from elsewhere import third_party
+4  5  | 
+5     |-from . import first_party
+   6  |+from typing import TYPE_CHECKING
+   7  |+
+   8  |+if TYPE_CHECKING:
+   9  |+    from . import first_party
+6  10 | 
+7  11 | 
+8  12 | def f(x: first_party.foo): ...

crates/ruff_linter/src/rules/flake8_type_checking/snapshots/ruff_linter__rules__flake8_type_checking__tests__add_future_import__TC001_TC001.py.snap

@@ -0,0 +1,32 @@
+---
+source: crates/ruff_linter/src/rules/flake8_type_checking/mod.rs
+---
+TC001.py:20:19: TC001 [*] Move application import `.TYP001` into a type-checking block
+   |
+19 | def f():
+20 |     from . import TYP001
+   |                   ^^^^^^ TC001
+21 |
+22 |     x: TYP001
+   |
+   = help: Move into type-checking block
+
+ℹ Unsafe fix
+2  2  | 
+3  3  | For typing-only import detection tests, see `TC002.py`.
+4  4  | """
+   5  |+from typing import TYPE_CHECKING
+   6  |+
+   7  |+if TYPE_CHECKING:
+   8  |+    from . import TYP001
+5  9  | 
+6  10 | 
+7  11 | def f():
+--------------------------------------------------------------------------------
+17 21 | 
+18 22 | 
+19 23 | def f():
+20    |-    from . import TYP001
+21 24 | 
+22 25 |     x: TYP001
+23 26 |

crates/ruff_linter/src/rules/flake8_type_checking/snapshots/ruff_linter__rules__flake8_type_checking__tests__add_future_import__TC001_TC001_future.py.snap

@@ -0,0 +1,56 @@
+---
+source: crates/ruff_linter/src/rules/flake8_type_checking/mod.rs
+---
+TC001_future.py:2:19: TC001 [*] Move application import `.first_party` into a type-checking block
+  |
+1 | def f():
+2 |     from . import first_party
+  |                   ^^^^^^^^^^^ TC001
+3 |
+4 |     def f(x: first_party.foo): ...
+  |
+  = help: Move into type-checking block
+
+ℹ Unsafe fix
+1   |-def f():
+  1 |+from __future__ import annotations
+  2 |+from typing import TYPE_CHECKING
+  3 |+
+  4 |+if TYPE_CHECKING:
+2 5 |     from . import first_party
+  6 |+def f():
+3 7 | 
+4 8 |     def f(x: first_party.foo): ...
+5 9 | 
+
+TC001_future.py:57:19: TC001 [*] Move application import `.foo` into a type-checking block
+   |
+56 | def n():
+57 |     from . import foo
+   |                   ^^^ TC001
+58 |
+59 |     def f(x: Union[foo.Ty, int]): ...
+   |
+   = help: Move into type-checking block
+
+ℹ Unsafe fix
+   1  |+from __future__ import annotations
+1  2  | def f():
+2  3  |     from . import first_party
+3  4  | 
+--------------------------------------------------------------------------------
+50 51 | 
+51 52 | 
+52 53 | # unions
+53    |-from typing import Union
+   54 |+from typing import Union, TYPE_CHECKING
+54 55 | 
+   56 |+if TYPE_CHECKING:
+   57 |+    from . import foo
+   58 |+
+55 59 | 
+56 60 | def n():
+57    |-    from . import foo
+58 61 | 
+59 62 |     def f(x: Union[foo.Ty, int]): ...
+60 63 |     def g(x: foo.Ty | int): ...

crates/ruff_linter/src/rules/flake8_type_checking/snapshots/ruff_linter__rules__flake8_type_checking__tests__add_future_import__TC001_TC001_future_present.py.snap

@@ -0,0 +1,23 @@
+---
+source: crates/ruff_linter/src/rules/flake8_type_checking/mod.rs
+---
+TC001_future_present.py:3:15: TC001 [*] Move application import `.first_party` into a type-checking block
+  |
+1 | from __future__ import annotations
+2 |
+3 | from . import first_party
+  |               ^^^^^^^^^^^ TC001
+  |
+  = help: Move into type-checking block
+
+ℹ Unsafe fix
+1 1 | from __future__ import annotations
+2 2 | 
+3   |-from . import first_party
+  3 |+from typing import TYPE_CHECKING
+  4 |+
+  5 |+if TYPE_CHECKING:
+  6 |+    from . import first_party
+4 7 | 
+5 8 | 
+6 9 | def f(x: first_party.foo): ...

crates/ruff_linter/src/rules/flake8_type_checking/snapshots/ruff_linter__rules__flake8_type_checking__tests__add_future_import__TC002_TC002.py.snap

@@ -0,0 +1,251 @@
+---
+source: crates/ruff_linter/src/rules/flake8_type_checking/mod.rs
+---
+TC002.py:5:22: TC002 [*] Move third-party import `pandas` into a type-checking block
+  |
+4 | def f():
+5 |     import pandas as pd  # TC002
+  |                      ^^ TC002
+6 |
+7 |     x: pd.DataFrame
+  |
+  = help: Move into type-checking block
+
+ℹ Unsafe fix
+1 1 | """Tests to determine accurate detection of typing-only imports."""
+  2 |+from typing import TYPE_CHECKING
+  3 |+
+  4 |+if TYPE_CHECKING:
+  5 |+    import pandas as pd
+2 6 | 
+3 7 | 
+4 8 | def f():
+5   |-    import pandas as pd  # TC002
+6 9 | 
+7 10 |     x: pd.DataFrame
+8 11 | 
+
+TC002.py:11:24: TC002 [*] Move third-party import `pandas.DataFrame` into a type-checking block
+   |
+10 | def f():
+11 |     from pandas import DataFrame  # TC002
+   |                        ^^^^^^^^^ TC002
+12 |
+13 |     x: DataFrame
+   |
+   = help: Move into type-checking block
+
+ℹ Unsafe fix
+1  1  | """Tests to determine accurate detection of typing-only imports."""
+   2  |+from typing import TYPE_CHECKING
+   3  |+
+   4  |+if TYPE_CHECKING:
+   5  |+    from pandas import DataFrame
+2  6  | 
+3  7  | 
+4  8  | def f():
+--------------------------------------------------------------------------------
+8  12 | 
+9  13 | 
+10 14 | def f():
+11    |-    from pandas import DataFrame  # TC002
+12 15 | 
+13 16 |     x: DataFrame
+14 17 | 
+
+TC002.py:17:37: TC002 [*] Move third-party import `pandas.DataFrame` into a type-checking block
+   |
+16 | def f():
+17 |     from pandas import DataFrame as df  # TC002
+   |                                     ^^ TC002
+18 |
+19 |     x: df
+   |
+   = help: Move into type-checking block
+
+ℹ Unsafe fix
+1  1  | """Tests to determine accurate detection of typing-only imports."""
+   2  |+from typing import TYPE_CHECKING
+   3  |+
+   4  |+if TYPE_CHECKING:
+   5  |+    from pandas import DataFrame as df
+2  6  | 
+3  7  | 
+4  8  | def f():
+--------------------------------------------------------------------------------
+14 18 | 
+15 19 | 
+16 20 | def f():
+17    |-    from pandas import DataFrame as df  # TC002
+18 21 | 
+19 22 |     x: df
+20 23 | 
+
+TC002.py:23:22: TC002 [*] Move third-party import `pandas` into a type-checking block
+   |
+22 | def f():
+23 |     import pandas as pd  # TC002
+   |                      ^^ TC002
+24 |
+25 |     x: pd.DataFrame = 1
+   |
+   = help: Move into type-checking block
+
+ℹ Unsafe fix
+1  1  | """Tests to determine accurate detection of typing-only imports."""
+   2  |+from typing import TYPE_CHECKING
+   3  |+
+   4  |+if TYPE_CHECKING:
+   5  |+    import pandas as pd
+2  6  | 
+3  7  | 
+4  8  | def f():
+--------------------------------------------------------------------------------
+20 24 | 
+21 25 | 
+22 26 | def f():
+23    |-    import pandas as pd  # TC002
+24 27 | 
+25 28 |     x: pd.DataFrame = 1
+26 29 | 
+
+TC002.py:29:24: TC002 [*] Move third-party import `pandas.DataFrame` into a type-checking block
+   |
+28 | def f():
+29 |     from pandas import DataFrame  # TC002
+   |                        ^^^^^^^^^ TC002
+30 |
+31 |     x: DataFrame = 2
+   |
+   = help: Move into type-checking block
+
+ℹ Unsafe fix
+1  1  | """Tests to determine accurate detection of typing-only imports."""
+   2  |+from typing import TYPE_CHECKING
+   3  |+
+   4  |+if TYPE_CHECKING:
+   5  |+    from pandas import DataFrame
+2  6  | 
+3  7  | 
+4  8  | def f():
+--------------------------------------------------------------------------------
+26 30 | 
+27 31 | 
+28 32 | def f():
+29    |-    from pandas import DataFrame  # TC002
+30 33 | 
+31 34 |     x: DataFrame = 2
+32 35 | 
+
+TC002.py:35:37: TC002 [*] Move third-party import `pandas.DataFrame` into a type-checking block
+   |
+34 | def f():
+35 |     from pandas import DataFrame as df  # TC002
+   |                                     ^^ TC002
+36 |
+37 |     x: df = 3
+   |
+   = help: Move into type-checking block
+
+ℹ Unsafe fix
+1  1  | """Tests to determine accurate detection of typing-only imports."""
+   2  |+from typing import TYPE_CHECKING
+   3  |+
+   4  |+if TYPE_CHECKING:
+   5  |+    from pandas import DataFrame as df
+2  6  | 
+3  7  | 
+4  8  | def f():
+--------------------------------------------------------------------------------
+32 36 | 
+33 37 | 
+34 38 | def f():
+35    |-    from pandas import DataFrame as df  # TC002
+36 39 | 
+37 40 |     x: df = 3
+38 41 | 
+
+TC002.py:41:22: TC002 [*] Move third-party import `pandas` into a type-checking block
+   |
+40 | def f():
+41 |     import pandas as pd  # TC002
+   |                      ^^ TC002
+42 |
+43 |     x: "pd.DataFrame" = 1
+   |
+   = help: Move into type-checking block
+
+ℹ Unsafe fix
+1  1  | """Tests to determine accurate detection of typing-only imports."""
+   2  |+from typing import TYPE_CHECKING
+   3  |+
+   4  |+if TYPE_CHECKING:
+   5  |+    import pandas as pd
+2  6  | 
+3  7  | 
+4  8  | def f():
+--------------------------------------------------------------------------------
+38 42 | 
+39 43 | 
+40 44 | def f():
+41    |-    import pandas as pd  # TC002
+42 45 | 
+43 46 |     x: "pd.DataFrame" = 1
+44 47 | 
+
+TC002.py:47:22: TC002 [*] Move third-party import `pandas` into a type-checking block
+   |
+46 | def f():
+47 |     import pandas as pd  # TC002
+   |                      ^^ TC002
+48 |
+49 |     x = dict["pd.DataFrame", "pd.DataFrame"]
+   |
+   = help: Move into type-checking block
+
+ℹ Unsafe fix
+1  1  | """Tests to determine accurate detection of typing-only imports."""
+   2  |+from typing import TYPE_CHECKING
+   3  |+
+   4  |+if TYPE_CHECKING:
+   5  |+    import pandas as pd
+2  6  | 
+3  7  | 
+4  8  | def f():
+--------------------------------------------------------------------------------
+44 48 | 
+45 49 | 
+46 50 | def f():
+47    |-    import pandas as pd  # TC002
+48 51 | 
+49 52 |     x = dict["pd.DataFrame", "pd.DataFrame"]
+50 53 | 
+
+TC002.py:172:24: TC002 [*] Move third-party import `module.Member` into a type-checking block
+    |
+170 |     global Member
+171 |
+172 |     from module import Member
+    |                        ^^^^^^ TC002
+173 |
+174 |     x: Member = 1
+    |
+    = help: Move into type-checking block
+
+ℹ Unsafe fix
+1   1   | """Tests to determine accurate detection of typing-only imports."""
+    2   |+from typing import TYPE_CHECKING
+    3   |+
+    4   |+if TYPE_CHECKING:
+    5   |+    from module import Member
+2   6   | 
+3   7   | 
+4   8   | def f():
+--------------------------------------------------------------------------------
+169 173 | def f():
+170 174 |     global Member
+171 175 | 
+172     |-    from module import Member
+173 176 | 
+174 177 |     x: Member = 1
+175 178 |

crates/ruff_linter/src/rules/flake8_type_checking/snapshots/ruff_linter__rules__flake8_type_checking__tests__add_future_import__TC003_TC003.py.snap

@@ -0,0 +1,28 @@
+---
+source: crates/ruff_linter/src/rules/flake8_type_checking/mod.rs
+---
+TC003.py:8:12: TC003 [*] Move standard library import `os` into a type-checking block
+   |
+ 7 | def f():
+ 8 |     import os
+   |            ^^ TC003
+ 9 |
+10 |     x: os
+   |
+   = help: Move into type-checking block
+
+ℹ Unsafe fix
+2  2  | 
+3  3  | For typing-only import detection tests, see `TC002.py`.
+4  4  | """
+   5  |+from typing import TYPE_CHECKING
+   6  |+
+   7  |+if TYPE_CHECKING:
+   8  |+    import os
+5  9  | 
+6  10 | 
+7  11 | def f():
+8     |-    import os
+9  12 | 
+10 13 |     x: os
+11 14 |

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

@@ -1,8 +1,8 @@
 use crate::checkers::ast::Checker;
 use crate::importer::ImportRequest;
 use crate::{Applicability, Edit, Fix, Violation};
-use ruff_python_ast::{self as ast};
-use ruff_python_ast::{Expr, ExprCall};
+use ruff_python_ast::{self as ast, Expr, ExprCall};
+use ruff_python_semantic::{SemanticModel, analyze::typing};
 use ruff_text_size::Ranged;
 
 pub(crate) fn is_keyword_only_argument_non_default(arguments: &ast::Arguments, name: &str) -> bool {
@@ -72,3 +72,85 @@ pub(crate) fn check_os_pathlib_single_arg_calls(
         });
     }
 }
+
+pub(crate) fn get_name_expr(expr: &Expr) -> Option<&ast::ExprName> {
+    match expr {
+        Expr::Name(name) => Some(name),
+        Expr::Call(ExprCall { func, .. }) => get_name_expr(func),
+        _ => None,
+    }
+}
+
+/// Returns `true` if the given expression looks like a file descriptor, i.e., if it is an integer.
+pub(crate) fn is_file_descriptor(expr: &Expr, semantic: &SemanticModel) -> bool {
+    if matches!(
+        expr,
+        Expr::NumberLiteral(ast::ExprNumberLiteral {
+            value: ast::Number::Int(_),
+            ..
+        })
+    ) {
+        return true;
+    }
+
+    let Some(name) = get_name_expr(expr) else {
+        return false;
+    };
+
+    let Some(binding) = semantic.only_binding(name).map(|id| semantic.binding(id)) else {
+        return false;
+    };
+
+    typing::is_int(binding, semantic)
+}
+
+pub(crate) fn check_os_pathlib_two_arg_calls(
+    checker: &Checker,
+    call: &ExprCall,
+    attr: &str,
+    path_arg: &str,
+    second_arg: &str,
+    fix_enabled: bool,
+    violation: impl Violation,
+) {
+    let range = call.range();
+    let mut diagnostic = checker.report_diagnostic(violation, call.func.range());
+
+    let (Some(path_expr), Some(second_expr)) = (
+        call.arguments.find_argument_value(path_arg, 0),
+        call.arguments.find_argument_value(second_arg, 1),
+    ) else {
+        return;
+    };
+
+    let path_code = checker.locator().slice(path_expr.range());
+    let second_code = checker.locator().slice(second_expr.range());
+
+    if fix_enabled {
+        diagnostic.try_set_fix(|| {
+            let (import_edit, binding) = checker.importer().get_or_import_symbol(
+                &ImportRequest::import("pathlib", "Path"),
+                call.start(),
+                checker.semantic(),
+            )?;
+
+            let replacement = if is_pathlib_path_call(checker, path_expr) {
+                format!("{path_code}.{attr}({second_code})")
+            } else {
+                format!("{binding}({path_code}).{attr}({second_code})")
+            };
+
+            let applicability = if checker.comment_ranges().intersects(range) {
+                Applicability::Unsafe
+            } else {
+                Applicability::Safe
+            };
+
+            Ok(Fix::applicable_edits(
+                Edit::range_replacement(replacement, range),
+                [import_edit],
+                applicability,
+            ))
+        });
+    }
+}

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

@@ -3,7 +3,7 @@ use crate::{Edit, Fix, FixAvailability, Violation};
 use ruff_macros::{ViolationMetadata, derive_message_formats};
 use ruff_python_ast::{self as ast, PythonVersion, StringFlags};
 use ruff_python_semantic::SemanticModel;
-use ruff_python_semantic::analyze::typing;
+use ruff_python_semantic::analyze::typing::{self, PathlibPathChecker, TypeChecker};
 use ruff_text_size::Ranged;
 
 /// ## What it does
@@ -141,12 +141,13 @@ fn is_path_with_suffix_call(semantic: &SemanticModel, func: &ast::Expr) -> bool
         return false;
     }
 
-    let ast::Expr::Name(name) = &**value else {
-        return false;
-    };
-    let Some(binding) = semantic.only_binding(name).map(|id| semantic.binding(id)) else {
-        return false;
-    };
-
-    typing::is_pathlib_path(binding, semantic)
+    match &**value {
+        ast::Expr::Name(name) => {
+            let Some(binding) = semantic.only_binding(name).map(|id| semantic.binding(id)) else {
+                return false;
+            };
+            typing::is_pathlib_path(binding, semantic)
+        }
+        expr => PathlibPathChecker::match_initializer(expr, semantic),
+    }
 }

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

@@ -1,5 +1,7 @@
 pub(crate) use glob_rule::*;
 pub(crate) use invalid_pathlib_with_suffix::*;
+pub(crate) use os_chmod::*;
+pub(crate) use os_getcwd::*;
 pub(crate) use os_path_abspath::*;
 pub(crate) use os_path_basename::*;
 pub(crate) use os_path_dirname::*;
@@ -13,8 +15,11 @@ pub(crate) use os_path_isabs::*;
 pub(crate) use os_path_isdir::*;
 pub(crate) use os_path_isfile::*;
 pub(crate) use os_path_islink::*;
+pub(crate) use os_path_samefile::*;
 pub(crate) use os_readlink::*;
 pub(crate) use os_remove::*;
+pub(crate) use os_rename::*;
+pub(crate) use os_replace::*;
 pub(crate) use os_rmdir::*;
 pub(crate) use os_sep_split::*;
 pub(crate) use os_unlink::*;
@@ -23,6 +28,8 @@ pub(crate) use replaceable_by_pathlib::*;
 
 mod glob_rule;
 mod invalid_pathlib_with_suffix;
+mod os_chmod;
+mod os_getcwd;
 mod os_path_abspath;
 mod os_path_basename;
 mod os_path_dirname;
@@ -36,8 +43,11 @@ mod os_path_isabs;
 mod os_path_isdir;
 mod os_path_isfile;
 mod os_path_islink;
+mod os_path_samefile;
 mod os_readlink;
 mod os_remove;
+mod os_rename;
+mod os_replace;
 mod os_rmdir;
 mod os_sep_split;
 mod os_unlink;

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

@@ -0,0 +1,94 @@
+use crate::checkers::ast::Checker;
+use crate::preview::is_fix_os_chmod_enabled;
+use crate::rules::flake8_use_pathlib::helpers::{
+    check_os_pathlib_two_arg_calls, is_file_descriptor, is_keyword_only_argument_non_default,
+};
+use crate::{FixAvailability, Violation};
+use ruff_macros::{ViolationMetadata, derive_message_formats};
+use ruff_python_ast::ExprCall;
+
+/// ## What it does
+/// Checks for uses of `os.chmod`.
+///
+/// ## Why is this bad?
+/// `pathlib` offers a high-level API for path manipulation, as compared to
+/// the lower-level API offered by `os`. When possible, using `Path` object
+/// methods such as `Path.chmod()` can improve readability over the `os`
+/// module's counterparts (e.g., `os.chmod()`).
+///
+/// ## Examples
+/// ```python
+/// import os
+///
+/// os.chmod("file.py", 0o444)
+/// ```
+///
+/// Use instead:
+/// ```python
+/// from pathlib import Path
+///
+/// Path("file.py").chmod(0o444)
+/// ```
+///
+/// ## Known issues
+/// While using `pathlib` can improve the readability and type safety of your code,
+/// it can be less performant than the lower-level alternatives that work directly with strings,
+/// especially on older versions of Python.
+///
+/// ## Fix Safety
+/// This rule's fix is marked as unsafe if the replacement would remove comments attached to the original expression.
+///
+/// ## References
+/// - [Python documentation: `Path.chmod`](https://docs.python.org/3/library/pathlib.html#pathlib.Path.chmod)
+/// - [Python documentation: `os.chmod`](https://docs.python.org/3/library/os.html#os.chmod)
+/// - [PEP 428 – The pathlib module – object-oriented filesystem paths](https://peps.python.org/pep-0428/)
+/// - [Correspondence between `os` and `pathlib`](https://docs.python.org/3/library/pathlib.html#correspondence-to-tools-in-the-os-module)
+/// - [Why you should be using pathlib](https://treyhunner.com/2018/12/why-you-should-be-using-pathlib/)
+/// - [No really, pathlib is great](https://treyhunner.com/2019/01/no-really-pathlib-is-great/)
+#[derive(ViolationMetadata)]
+pub(crate) struct OsChmod;
+
+impl Violation for OsChmod {
+    const FIX_AVAILABILITY: FixAvailability = FixAvailability::Sometimes;
+
+    #[derive_message_formats]
+    fn message(&self) -> String {
+        "`os.chmod()` should be replaced by `Path.chmod()`".to_string()
+    }
+
+    fn fix_title(&self) -> Option<String> {
+        Some("Replace with `Path(...).chmod(...)`".to_string())
+    }
+}
+
+/// PTH101
+pub(crate) fn os_chmod(checker: &Checker, call: &ExprCall, segments: &[&str]) {
+    if segments != ["os", "chmod"] {
+        return;
+    }
+
+    // `dir_fd` is not supported by pathlib, so check if it's set to non-default values.
+    // Signature as of Python 3.13 (https://docs.python.org/3/library/os.html#os.chmod)
+    // ```text
+    //           0     1          2               3
+    // os.chmod(path, mode, *, dir_fd=None, follow_symlinks=True)
+    // ```
+    if call
+        .arguments
+        .find_argument_value("path", 0)
+        .is_some_and(|expr| is_file_descriptor(expr, checker.semantic()))
+        || is_keyword_only_argument_non_default(&call.arguments, "dir_fd")
+    {
+        return;
+    }
+
+    check_os_pathlib_two_arg_calls(
+        checker,
+        call,
+        "chmod",
+        "path",
+        "mode",
+        is_fix_os_chmod_enabled(checker.settings()),
+        OsChmod,
+    );
+}

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

@@ -0,0 +1,100 @@
+use crate::checkers::ast::Checker;
+use crate::importer::ImportRequest;
+use crate::preview::is_fix_os_getcwd_enabled;
+use crate::{FixAvailability, Violation};
+use ruff_diagnostics::{Applicability, Edit, Fix};
+use ruff_macros::{ViolationMetadata, derive_message_formats};
+use ruff_python_ast::ExprCall;
+use ruff_text_size::Ranged;
+
+/// ## What it does
+/// Checks for uses of `os.getcwd` and `os.getcwdb`.
+///
+/// ## Why is this bad?
+/// `pathlib` offers a high-level API for path manipulation, as compared to
+/// the lower-level API offered by `os`. When possible, using `Path` object
+/// methods such as `Path.cwd()` can improve readability over the `os`
+/// module's counterparts (e.g., `os.getcwd()`).
+///
+/// ## Examples
+/// ```python
+/// import os
+///
+/// cwd = os.getcwd()
+/// ```
+///
+/// Use instead:
+/// ```python
+/// from pathlib import Path
+///
+/// cwd = Path.cwd()
+/// ```
+///
+/// ## Known issues
+/// While using `pathlib` can improve the readability and type safety of your code,
+/// it can be less performant than the lower-level alternatives that work directly with strings,
+/// especially on older versions of Python.
+///
+/// ## Fix Safety
+/// This rule's fix is marked as unsafe if the replacement would remove comments attached to the original expression.
+///
+/// ## References
+/// - [Python documentation: `Path.cwd`](https://docs.python.org/3/library/pathlib.html#pathlib.Path.cwd)
+/// - [Python documentation: `os.getcwd`](https://docs.python.org/3/library/os.html#os.getcwd)
+/// - [Python documentation: `os.getcwdb`](https://docs.python.org/3/library/os.html#os.getcwdb)
+/// - [PEP 428 – The pathlib module – object-oriented filesystem paths](https://peps.python.org/pep-0428/)
+/// - [Correspondence between `os` and `pathlib`](https://docs.python.org/3/library/pathlib.html#correspondence-to-tools-in-the-os-module)
+/// - [Why you should be using pathlib](https://treyhunner.com/2018/12/why-you-should-be-using-pathlib/)
+/// - [No really, pathlib is great](https://treyhunner.com/2019/01/no-really-pathlib-is-great/)
+#[derive(ViolationMetadata)]
+pub(crate) struct OsGetcwd;
+
+impl Violation for OsGetcwd {
+    const FIX_AVAILABILITY: FixAvailability = FixAvailability::Sometimes;
+    #[derive_message_formats]
+    fn message(&self) -> String {
+        "`os.getcwd()` should be replaced by `Path.cwd()`".to_string()
+    }
+
+    fn fix_title(&self) -> Option<String> {
+        Some("Replace with `Path.cwd()`".to_string())
+    }
+}
+
+/// PTH109
+pub(crate) fn os_getcwd(checker: &Checker, call: &ExprCall, segments: &[&str]) {
+    if !matches!(segments, ["os", "getcwd" | "getcwdb"]) {
+        return;
+    }
+
+    let range = call.range();
+    let mut diagnostic = checker.report_diagnostic(OsGetcwd, call.func.range());
+
+    if !call.arguments.is_empty() {
+        return;
+    }
+
+    if is_fix_os_getcwd_enabled(checker.settings()) {
+        diagnostic.try_set_fix(|| {
+            let (import_edit, binding) = checker.importer().get_or_import_symbol(
+                &ImportRequest::import("pathlib", "Path"),
+                call.start(),
+                checker.semantic(),
+            )?;
+
+            let applicability = if checker.comment_ranges().intersects(range) {
+                Applicability::Unsafe
+            } else {
+                Applicability::Safe
+            };
+
+            let replacement = format!("{binding}.cwd()");
+
+            Ok(Fix::applicable_edits(
+                Edit::range_replacement(replacement, range),
+                [import_edit],
+                applicability,
+            ))
+        });
+    }
+}

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

@@ -0,0 +1,77 @@
+use crate::checkers::ast::Checker;
+use crate::preview::is_fix_os_path_samefile_enabled;
+use crate::rules::flake8_use_pathlib::helpers::check_os_pathlib_two_arg_calls;
+use crate::{FixAvailability, Violation};
+use ruff_macros::{ViolationMetadata, derive_message_formats};
+use ruff_python_ast::ExprCall;
+
+/// ## What it does
+/// Checks for uses of `os.path.samefile`.
+///
+/// ## Why is this bad?
+/// `pathlib` offers a high-level API for path manipulation, as compared to
+/// the lower-level API offered by `os.path`. When possible, using `Path` object
+/// methods such as `Path.samefile()` can improve readability over the `os.path`
+/// module's counterparts (e.g., `os.path.samefile()`).
+///
+/// ## Examples
+/// ```python
+/// import os
+///
+/// os.path.samefile("f1.py", "f2.py")
+/// ```
+///
+/// Use instead:
+/// ```python
+/// from pathlib import Path
+///
+/// Path("f1.py").samefile("f2.py")
+/// ```
+///
+/// ## Known issues
+/// While using `pathlib` can improve the readability and type safety of your code,
+/// it can be less performant than the lower-level alternatives that work directly with strings,
+/// especially on older versions of Python.
+///
+/// ## Fix Safety
+/// This rule's fix is marked as unsafe if the replacement would remove comments attached to the original expression.
+///
+/// ## References
+/// - [Python documentation: `Path.samefile`](https://docs.python.org/3/library/pathlib.html#pathlib.Path.samefile)
+/// - [Python documentation: `os.path.samefile`](https://docs.python.org/3/library/os.path.html#os.path.samefile)
+/// - [PEP 428 – The pathlib module – object-oriented filesystem paths](https://peps.python.org/pep-0428/)
+/// - [Correspondence between `os` and `pathlib`](https://docs.python.org/3/library/pathlib.html#correspondence-to-tools-in-the-os-module)
+/// - [Why you should be using pathlib](https://treyhunner.com/2018/12/why-you-should-be-using-pathlib/)
+/// - [No really, pathlib is great](https://treyhunner.com/2019/01/no-really-pathlib-is-great/)
+#[derive(ViolationMetadata)]
+pub(crate) struct OsPathSamefile;
+
+impl Violation for OsPathSamefile {
+    const FIX_AVAILABILITY: FixAvailability = FixAvailability::Sometimes;
+
+    #[derive_message_formats]
+    fn message(&self) -> String {
+        "`os.path.samefile()` should be replaced by `Path.samefile()`".to_string()
+    }
+
+    fn fix_title(&self) -> Option<String> {
+        Some("Replace with `Path(...).samefile()`".to_string())
+    }
+}
+
+/// PTH121
+pub(crate) fn os_path_samefile(checker: &Checker, call: &ExprCall, segments: &[&str]) {
+    if segments != ["os", "path", "samefile"] {
+        return;
+    }
+
+    check_os_pathlib_two_arg_calls(
+        checker,
+        call,
+        "samefile",
+        "f1",
+        "f2",
+        is_fix_os_path_samefile_enabled(checker.settings()),
+        OsPathSamefile,
+    );
+}

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

@@ -0,0 +1,91 @@
+use crate::checkers::ast::Checker;
+use crate::preview::is_fix_os_rename_enabled;
+use crate::rules::flake8_use_pathlib::helpers::{
+    check_os_pathlib_two_arg_calls, is_keyword_only_argument_non_default,
+};
+use crate::{FixAvailability, Violation};
+use ruff_macros::{ViolationMetadata, derive_message_formats};
+use ruff_python_ast::ExprCall;
+
+/// ## What it does
+/// Checks for uses of `os.rename`.
+///
+/// ## Why is this bad?
+/// `pathlib` offers a high-level API for path manipulation, as compared to
+/// the lower-level API offered by `os`. When possible, using `Path` object
+/// methods such as `Path.rename()` can improve readability over the `os`
+/// module's counterparts (e.g., `os.rename()`).
+///
+/// ## Examples
+/// ```python
+/// import os
+///
+/// os.rename("old.py", "new.py")
+/// ```
+///
+/// Use instead:
+/// ```python
+/// from pathlib import Path
+///
+/// Path("old.py").rename("new.py")
+/// ```
+///
+/// ## Known issues
+/// While using `pathlib` can improve the readability and type safety of your code,
+/// it can be less performant than the lower-level alternatives that work directly with strings,
+/// especially on older versions of Python.
+///
+/// ## Fix Safety
+/// This rule's fix is marked as unsafe if the replacement would remove comments attached to the original expression.
+///
+/// ## References
+/// - [Python documentation: `Path.rename`](https://docs.python.org/3/library/pathlib.html#pathlib.Path.rename)
+/// - [Python documentation: `os.rename`](https://docs.python.org/3/library/os.html#os.rename)
+/// - [PEP 428 – The pathlib module – object-oriented filesystem paths](https://peps.python.org/pep-0428/)
+/// - [Correspondence between `os` and `pathlib`](https://docs.python.org/3/library/pathlib.html#correspondence-to-tools-in-the-os-module)
+/// - [Why you should be using pathlib](https://treyhunner.com/2018/12/why-you-should-be-using-pathlib/)
+/// - [No really, pathlib is great](https://treyhunner.com/2019/01/no-really-pathlib-is-great/)
+#[derive(ViolationMetadata)]
+pub(crate) struct OsRename;
+
+impl Violation for OsRename {
+    const FIX_AVAILABILITY: FixAvailability = FixAvailability::Sometimes;
+
+    #[derive_message_formats]
+    fn message(&self) -> String {
+        "`os.rename()` should be replaced by `Path.rename()`".to_string()
+    }
+
+    fn fix_title(&self) -> Option<String> {
+        Some("Replace with `Path(...).rename(...)`".to_string())
+    }
+}
+
+/// PTH104
+pub(crate) fn os_rename(checker: &Checker, call: &ExprCall, segments: &[&str]) {
+    if segments != ["os", "rename"] {
+        return;
+    }
+    // `src_dir_fd` and `dst_dir_fd` are not supported by pathlib, so check if they are
+    // set to non-default values.
+    // Signature as of Python 3.13 (https://docs.python.org/3/library/os.html#os.rename)
+    // ```text
+    //            0    1           2                  3
+    // os.rename(src, dst, *, src_dir_fd=None, dst_dir_fd=None)
+    // ```
+    if is_keyword_only_argument_non_default(&call.arguments, "src_dir_fd")
+        || is_keyword_only_argument_non_default(&call.arguments, "dst_dir_fd")
+    {
+        return;
+    }
+
+    check_os_pathlib_two_arg_calls(
+        checker,
+        call,
+        "rename",
+        "src",
+        "dst",
+        is_fix_os_rename_enabled(checker.settings()),
+        OsRename,
+    );
+}

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

@@ -0,0 +1,94 @@
+use crate::checkers::ast::Checker;
+use crate::preview::is_fix_os_replace_enabled;
+use crate::rules::flake8_use_pathlib::helpers::{
+    check_os_pathlib_two_arg_calls, is_keyword_only_argument_non_default,
+};
+use crate::{FixAvailability, Violation};
+use ruff_macros::{ViolationMetadata, derive_message_formats};
+use ruff_python_ast::ExprCall;
+
+/// ## What it does
+/// Checks for uses of `os.replace`.
+///
+/// ## Why is this bad?
+/// `pathlib` offers a high-level API for path manipulation, as compared to
+/// the lower-level API offered by `os`. When possible, using `Path` object
+/// methods such as `Path.replace()` can improve readability over the `os`
+/// module's counterparts (e.g., `os.replace()`).
+///
+/// Note that `os` functions may be preferable if performance is a concern,
+/// e.g., in hot loops.
+///
+/// ## Examples
+/// ```python
+/// import os
+///
+/// os.replace("old.py", "new.py")
+/// ```
+///
+/// Use instead:
+/// ```python
+/// from pathlib import Path
+///
+/// Path("old.py").replace("new.py")
+/// ```
+///
+/// ## Known issues
+/// While using `pathlib` can improve the readability and type safety of your code,
+/// it can be less performant than the lower-level alternatives that work directly with strings,
+/// especially on older versions of Python.
+///
+/// ## Fix Safety
+/// This rule's fix is marked as unsafe if the replacement would remove comments attached to the original expression.
+///
+/// ## References
+/// - [Python documentation: `Path.replace`](https://docs.python.org/3/library/pathlib.html#pathlib.Path.replace)
+/// - [Python documentation: `os.replace`](https://docs.python.org/3/library/os.html#os.replace)
+/// - [PEP 428 – The pathlib module – object-oriented filesystem paths](https://peps.python.org/pep-0428/)
+/// - [Correspondence between `os` and `pathlib`](https://docs.python.org/3/library/pathlib.html#correspondence-to-tools-in-the-os-module)
+/// - [Why you should be using pathlib](https://treyhunner.com/2018/12/why-you-should-be-using-pathlib/)
+/// - [No really, pathlib is great](https://treyhunner.com/2019/01/no-really-pathlib-is-great/)
+#[derive(ViolationMetadata)]
+pub(crate) struct OsReplace;
+
+impl Violation for OsReplace {
+    const FIX_AVAILABILITY: FixAvailability = FixAvailability::Sometimes;
+
+    #[derive_message_formats]
+    fn message(&self) -> String {
+        "`os.replace()` should be replaced by `Path.replace()`".to_string()
+    }
+
+    fn fix_title(&self) -> Option<String> {
+        Some("Replace with `Path(...).replace(...)`".to_string())
+    }
+}
+
+/// PTH105
+pub(crate) fn os_replace(checker: &Checker, call: &ExprCall, segments: &[&str]) {
+    if segments != ["os", "replace"] {
+        return;
+    }
+    // `src_dir_fd` and `dst_dir_fd` are not supported by pathlib, so check if they are
+    // set to non-default values.
+    // Signature as of Python 3.13 (https://docs.python.org/3/library/os.html#os.replace)
+    // ```text
+    //             0    1           2                3
+    // os.replace(src, dst, *, src_dir_fd=None, dst_dir_fd=None)
+    // ```
+    if is_keyword_only_argument_non_default(&call.arguments, "src_dir_fd")
+        || is_keyword_only_argument_non_default(&call.arguments, "dst_dir_fd")
+    {
+        return;
+    }
+
+    check_os_pathlib_two_arg_calls(
+        checker,
+        call,
+        "replace",
+        "src",
+        "dst",
+        is_fix_os_replace_enabled(checker.settings()),
+        OsReplace,
+    );
+}

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

@@ -1,14 +1,16 @@
 use ruff_python_ast::{self as ast, Expr, ExprBooleanLiteral, ExprCall};
-use ruff_python_semantic::SemanticModel;
-use ruff_python_semantic::analyze::typing;
 use ruff_text_size::Ranged;
 
 use crate::checkers::ast::Checker;
-use crate::rules::flake8_use_pathlib::helpers::is_keyword_only_argument_non_default;
-use crate::rules::flake8_use_pathlib::rules::Glob;
-use crate::rules::flake8_use_pathlib::violations::{
-    BuiltinOpen, Joiner, OsChmod, OsGetcwd, OsListdir, OsMakedirs, OsMkdir, OsPathJoin,
-    OsPathSamefile, OsPathSplitext, OsRename, OsReplace, OsStat, OsSymlink, PyPath,
+use crate::rules::flake8_use_pathlib::helpers::{
+    is_file_descriptor, is_keyword_only_argument_non_default,
+};
+use crate::rules::flake8_use_pathlib::{
+    rules::Glob,
+    violations::{
+        BuiltinOpen, Joiner, OsListdir, OsMakedirs, OsMkdir, OsPathJoin, OsPathSplitext, OsStat,
+        OsSymlink, PyPath,
+    },
 };
 
 pub(crate) fn replaceable_by_pathlib(checker: &Checker, call: &ExprCall) {
@@ -18,24 +20,6 @@ pub(crate) fn replaceable_by_pathlib(checker: &Checker, call: &ExprCall) {
 
     let range = call.func.range();
     match qualified_name.segments() {
-        // PTH101
-        ["os", "chmod"] => {
-            // `dir_fd` is not supported by pathlib, so check if it's set to non-default values.
-            // Signature as of Python 3.13 (https://docs.python.org/3/library/os.html#os.chmod)
-            // ```text
-            //           0     1          2               3
-            // os.chmod(path, mode, *, dir_fd=None, follow_symlinks=True)
-            // ```
-            if call
-                .arguments
-                .find_argument_value("path", 0)
-                .is_some_and(|expr| is_file_descriptor(expr, checker.semantic()))
-                || is_keyword_only_argument_non_default(&call.arguments, "dir_fd")
-            {
-                return;
-            }
-            checker.report_diagnostic_if_enabled(OsChmod, range)
-        }
         // PTH102
         ["os", "makedirs"] => checker.report_diagnostic_if_enabled(OsMakedirs, range),
         // PTH103
@@ -51,42 +35,6 @@ pub(crate) fn replaceable_by_pathlib(checker: &Checker, call: &ExprCall) {
             }
             checker.report_diagnostic_if_enabled(OsMkdir, range)
         }
-        // PTH104
-        ["os", "rename"] => {
-            // `src_dir_fd` and `dst_dir_fd` are not supported by pathlib, so check if they are
-            // set to non-default values.
-            // Signature as of Python 3.13 (https://docs.python.org/3/library/os.html#os.rename)
-            // ```text
-            //           0    1       2                3
-            // os.rename(src, dst, *, src_dir_fd=None, dst_dir_fd=None)
-            // ```
-            if is_keyword_only_argument_non_default(&call.arguments, "src_dir_fd")
-                || is_keyword_only_argument_non_default(&call.arguments, "dst_dir_fd")
-            {
-                return;
-            }
-            checker.report_diagnostic_if_enabled(OsRename, range)
-        }
-        // PTH105
-        ["os", "replace"] => {
-            // `src_dir_fd` and `dst_dir_fd` are not supported by pathlib, so check if they are
-            // set to non-default values.
-            // Signature as of Python 3.13 (https://docs.python.org/3/library/os.html#os.replace)
-            // ```text
-            //              0    1       2                3
-            // os.replace(src, dst, *, src_dir_fd=None, dst_dir_fd=None)
-            // ```
-            if is_keyword_only_argument_non_default(&call.arguments, "src_dir_fd")
-                || is_keyword_only_argument_non_default(&call.arguments, "dst_dir_fd")
-            {
-                return;
-            }
-            checker.report_diagnostic_if_enabled(OsReplace, range)
-        }
-        // PTH109
-        ["os", "getcwd"] => checker.report_diagnostic_if_enabled(OsGetcwd, range),
-        ["os", "getcwdb"] => checker.report_diagnostic_if_enabled(OsGetcwd, range),
-
         // PTH116
         ["os", "stat"] => {
             // `dir_fd` is not supported by pathlib, so check if it's set to non-default values.
@@ -128,8 +76,6 @@ pub(crate) fn replaceable_by_pathlib(checker: &Checker, call: &ExprCall) {
             },
             range,
         ),
-        // PTH121
-        ["os", "path", "samefile"] => checker.report_diagnostic_if_enabled(OsPathSamefile, range),
         // PTH122
         ["os", "path", "splitext"] => checker.report_diagnostic_if_enabled(OsPathSplitext, range),
         // PTH211
@@ -238,37 +184,6 @@ pub(crate) fn replaceable_by_pathlib(checker: &Checker, call: &ExprCall) {
     };
 }
 
-/// Returns `true` if the given expression looks like a file descriptor, i.e., if it is an integer.
-fn is_file_descriptor(expr: &Expr, semantic: &SemanticModel) -> bool {
-    if matches!(
-        expr,
-        Expr::NumberLiteral(ast::ExprNumberLiteral {
-            value: ast::Number::Int(_),
-            ..
-        })
-    ) {
-        return true;
-    }
-
-    let Some(name) = get_name_expr(expr) else {
-        return false;
-    };
-
-    let Some(binding) = semantic.only_binding(name).map(|id| semantic.binding(id)) else {
-        return false;
-    };
-
-    typing::is_int(binding, semantic)
-}
-
-fn get_name_expr(expr: &Expr) -> Option<&ast::ExprName> {
-    match expr {
-        Expr::Name(name) => Some(name),
-        Expr::Call(ExprCall { func, .. }) => get_name_expr(func),
-        _ => None,
-    }
-}
-
 /// Returns `true` if argument `name` is set to a non-default `None` value.
 fn is_argument_non_default(arguments: &ast::Arguments, name: &str, position: usize) -> bool {
     arguments

crates/ruff_linter/src/rules/flake8_use_pathlib/snapshots/ruff_linter__rules__flake8_use_pathlib__tests__PTH210_PTH210.py.snap

@@ -536,7 +536,7 @@ PTH210.py:54:1: PTH210 [*] Dotless suffix passed to `.with_suffix()`
    54 |+windows_path.with_suffix(u'.' "json")
 55 55 | windows_path.with_suffix(suffix="js")
 56 56 | 
-57 57 | 
+57 57 | Path().with_suffix(".")
 
 PTH210.py:55:1: PTH210 [*] Dotless suffix passed to `.with_suffix()`
    |
@@ -544,6 +544,8 @@ PTH210.py:55:1: PTH210 [*] Dotless suffix passed to `.with_suffix()`
 54 | windows_path.with_suffix(u'' "json")
 55 | windows_path.with_suffix(suffix="js")
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ PTH210
+56 |
+57 | Path().with_suffix(".")
    |
    = help: Add a leading dot
 
@@ -554,5 +556,140 @@ PTH210.py:55:1: PTH210 [*] Dotless suffix passed to `.with_suffix()`
 55    |-windows_path.with_suffix(suffix="js")
    55 |+windows_path.with_suffix(suffix=".js")
 56 56 | 
-57 57 | 
-58 58 | ### No errors
+57 57 | Path().with_suffix(".")
+58 58 | Path().with_suffix("py")
+
+PTH210.py:57:1: PTH210 Invalid suffix passed to `.with_suffix()`
+   |
+55 | windows_path.with_suffix(suffix="js")
+56 |
+57 | Path().with_suffix(".")
+   | ^^^^^^^^^^^^^^^^^^^^^^^ PTH210
+58 | Path().with_suffix("py")
+59 | PosixPath().with_suffix("py")
+   |
+   = help: Remove "." or extend to valid suffix
+
+PTH210.py:58:1: PTH210 [*] Dotless suffix passed to `.with_suffix()`
+   |
+57 | Path().with_suffix(".")
+58 | Path().with_suffix("py")
+   | ^^^^^^^^^^^^^^^^^^^^^^^^ PTH210
+59 | PosixPath().with_suffix("py")
+60 | PurePath().with_suffix("py")
+   |
+   = help: Add a leading dot
+
+ℹ Unsafe fix
+55 55 | windows_path.with_suffix(suffix="js")
+56 56 | 
+57 57 | Path().with_suffix(".")
+58    |-Path().with_suffix("py")
+   58 |+Path().with_suffix(".py")
+59 59 | PosixPath().with_suffix("py")
+60 60 | PurePath().with_suffix("py")
+61 61 | PurePosixPath().with_suffix("py")
+
+PTH210.py:59:1: PTH210 [*] Dotless suffix passed to `.with_suffix()`
+   |
+57 | Path().with_suffix(".")
+58 | Path().with_suffix("py")
+59 | PosixPath().with_suffix("py")
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ PTH210
+60 | PurePath().with_suffix("py")
+61 | PurePosixPath().with_suffix("py")
+   |
+   = help: Add a leading dot
+
+ℹ Unsafe fix
+56 56 | 
+57 57 | Path().with_suffix(".")
+58 58 | Path().with_suffix("py")
+59    |-PosixPath().with_suffix("py")
+   59 |+PosixPath().with_suffix(".py")
+60 60 | PurePath().with_suffix("py")
+61 61 | PurePosixPath().with_suffix("py")
+62 62 | PureWindowsPath().with_suffix("py")
+
+PTH210.py:60:1: PTH210 [*] Dotless suffix passed to `.with_suffix()`
+   |
+58 | Path().with_suffix("py")
+59 | PosixPath().with_suffix("py")
+60 | PurePath().with_suffix("py")
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ PTH210
+61 | PurePosixPath().with_suffix("py")
+62 | PureWindowsPath().with_suffix("py")
+   |
+   = help: Add a leading dot
+
+ℹ Unsafe fix
+57 57 | Path().with_suffix(".")
+58 58 | Path().with_suffix("py")
+59 59 | PosixPath().with_suffix("py")
+60    |-PurePath().with_suffix("py")
+   60 |+PurePath().with_suffix(".py")
+61 61 | PurePosixPath().with_suffix("py")
+62 62 | PureWindowsPath().with_suffix("py")
+63 63 | WindowsPath().with_suffix("py")
+
+PTH210.py:61:1: PTH210 [*] Dotless suffix passed to `.with_suffix()`
+   |
+59 | PosixPath().with_suffix("py")
+60 | PurePath().with_suffix("py")
+61 | PurePosixPath().with_suffix("py")
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ PTH210
+62 | PureWindowsPath().with_suffix("py")
+63 | WindowsPath().with_suffix("py")
+   |
+   = help: Add a leading dot
+
+ℹ Unsafe fix
+58 58 | Path().with_suffix("py")
+59 59 | PosixPath().with_suffix("py")
+60 60 | PurePath().with_suffix("py")
+61    |-PurePosixPath().with_suffix("py")
+   61 |+PurePosixPath().with_suffix(".py")
+62 62 | PureWindowsPath().with_suffix("py")
+63 63 | WindowsPath().with_suffix("py")
+64 64 | 
+
+PTH210.py:62:1: PTH210 [*] Dotless suffix passed to `.with_suffix()`
+   |
+60 | PurePath().with_suffix("py")
+61 | PurePosixPath().with_suffix("py")
+62 | PureWindowsPath().with_suffix("py")
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ PTH210
+63 | WindowsPath().with_suffix("py")
+   |
+   = help: Add a leading dot
+
+ℹ Unsafe fix
+59 59 | PosixPath().with_suffix("py")
+60 60 | PurePath().with_suffix("py")
+61 61 | PurePosixPath().with_suffix("py")
+62    |-PureWindowsPath().with_suffix("py")
+   62 |+PureWindowsPath().with_suffix(".py")
+63 63 | WindowsPath().with_suffix("py")
+64 64 | 
+65 65 | ### No errors
+
+PTH210.py:63:1: PTH210 [*] Dotless suffix passed to `.with_suffix()`
+   |
+61 | PurePosixPath().with_suffix("py")
+62 | PureWindowsPath().with_suffix("py")
+63 | WindowsPath().with_suffix("py")
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ PTH210
+64 |
+65 | ### No errors
+   |
+   = help: Add a leading dot
+
+ℹ Unsafe fix
+60 60 | PurePath().with_suffix("py")
+61 61 | PurePosixPath().with_suffix("py")
+62 62 | PureWindowsPath().with_suffix("py")
+63    |-WindowsPath().with_suffix("py")
+   63 |+WindowsPath().with_suffix(".py")
+64 64 | 
+65 65 | ### No errors
+66 66 | path.with_suffix()

crates/ruff_linter/src/rules/flake8_use_pathlib/snapshots/ruff_linter__rules__flake8_use_pathlib__tests__full_name.py.snap

@@ -20,6 +20,7 @@ full_name.py:8:6: PTH101 `os.chmod()` should be replaced by `Path.chmod()`
  9 | aaa = os.mkdir(p)
 10 | os.makedirs(p)
    |
+   = help: Replace with `Path(...).chmod(...)`
 
 full_name.py:9:7: PTH102 `os.mkdir()` should be replaced by `Path.mkdir()`
    |
@@ -50,6 +51,7 @@ full_name.py:11:1: PTH104 `os.rename()` should be replaced by `Path.rename()`
 12 | os.replace(p)
 13 | os.rmdir(p)
    |
+   = help: Replace with `Path(...).rename(...)`
 
 full_name.py:12:1: PTH105 `os.replace()` should be replaced by `Path.replace()`
    |
@@ -60,6 +62,7 @@ full_name.py:12:1: PTH105 `os.replace()` should be replaced by `Path.replace()`
 13 | os.rmdir(p)
 14 | os.remove(p)
    |
+   = help: Replace with `Path(...).replace(...)`
 
 full_name.py:13:1: PTH106 `os.rmdir()` should be replaced by `Path.rmdir()`
    |
@@ -103,6 +106,7 @@ full_name.py:16:1: PTH109 `os.getcwd()` should be replaced by `Path.cwd()`
 17 | b = os.path.exists(p)
 18 | bb = os.path.expanduser(p)
    |
+   = help: Replace with `Path.cwd()`
 
 full_name.py:17:5: PTH110 `os.path.exists()` should be replaced by `Path.exists()`
    |
@@ -252,6 +256,7 @@ full_name.py:30:1: PTH121 `os.path.samefile()` should be replaced by `Path.samef
 31 | os.path.splitext(p)
 32 | with open(p) as fp:
    |
+   = help: Replace with `Path(...).samefile()`
 
 full_name.py:31:1: PTH122 `os.path.splitext()` should be replaced by `Path.suffix`, `Path.stem`, and `Path.parent`
    |
@@ -292,6 +297,7 @@ full_name.py:35:1: PTH109 `os.getcwd()` should be replaced by `Path.cwd()`
 36 | os.path.join(p, *q)
 37 | os.sep.join(p, *q)
    |
+   = help: Replace with `Path.cwd()`
 
 full_name.py:36:1: PTH118 `os.path.join()` should be replaced by `Path.joinpath()`
    |
@@ -360,3 +366,21 @@ full_name.py:71:1: PTH123 `open()` should be replaced by `Path.open()`
 72 |
 73 | # https://github.com/astral-sh/ruff/issues/17693
    |
+
+full_name.py:108:1: PTH109 `os.getcwd()` should be replaced by `Path.cwd()`
+    |
+106 | os.replace("src", "dst", dst_dir_fd=2)
+107 |
+108 | os.getcwd()
+    | ^^^^^^^^^ PTH109
+109 | os.getcwdb()
+    |
+    = help: Replace with `Path.cwd()`
+
+full_name.py:109:1: PTH109 `os.getcwd()` should be replaced by `Path.cwd()`
+    |
+108 | os.getcwd()
+109 | os.getcwdb()
+    | ^^^^^^^^^^ PTH109
+    |
+    = help: Replace with `Path.cwd()`

crates/ruff_linter/src/rules/flake8_use_pathlib/snapshots/ruff_linter__rules__flake8_use_pathlib__tests__import_as.py.snap

@@ -20,6 +20,7 @@ import_as.py:8:6: PTH101 `os.chmod()` should be replaced by `Path.chmod()`
  9 | aaa = foo.mkdir(p)
 10 | foo.makedirs(p)
    |
+   = help: Replace with `Path(...).chmod(...)`
 
 import_as.py:9:7: PTH102 `os.mkdir()` should be replaced by `Path.mkdir()`
    |
@@ -50,6 +51,7 @@ import_as.py:11:1: PTH104 `os.rename()` should be replaced by `Path.rename()`
 12 | foo.replace(p)
 13 | foo.rmdir(p)
    |
+   = help: Replace with `Path(...).rename(...)`
 
 import_as.py:12:1: PTH105 `os.replace()` should be replaced by `Path.replace()`
    |
@@ -60,6 +62,7 @@ import_as.py:12:1: PTH105 `os.replace()` should be replaced by `Path.replace()`
 13 | foo.rmdir(p)
 14 | foo.remove(p)
    |
+   = help: Replace with `Path(...).replace(...)`
 
 import_as.py:13:1: PTH106 `os.rmdir()` should be replaced by `Path.rmdir()`
    |
@@ -103,6 +106,7 @@ import_as.py:16:1: PTH109 `os.getcwd()` should be replaced by `Path.cwd()`
 17 | b = foo_p.exists(p)
 18 | bb = foo_p.expanduser(p)
    |
+   = help: Replace with `Path.cwd()`
 
 import_as.py:17:5: PTH110 `os.path.exists()` should be replaced by `Path.exists()`
    |
@@ -251,6 +255,7 @@ import_as.py:30:1: PTH121 `os.path.samefile()` should be replaced by `Path.samef
    | ^^^^^^^^^^^^^^ PTH121
 31 | foo_p.splitext(p)
    |
+   = help: Replace with `Path(...).samefile()`
 
 import_as.py:31:1: PTH122 `os.path.splitext()` should be replaced by `Path.suffix`, `Path.stem`, and `Path.parent`
    |

crates/ruff_linter/src/rules/flake8_use_pathlib/snapshots/ruff_linter__rules__flake8_use_pathlib__tests__import_from.py.snap

@@ -20,6 +20,7 @@ import_from.py:10:6: PTH101 `os.chmod()` should be replaced by `Path.chmod()`
 11 | aaa = mkdir(p)
 12 | makedirs(p)
    |
+   = help: Replace with `Path(...).chmod(...)`
 
 import_from.py:11:7: PTH102 `os.mkdir()` should be replaced by `Path.mkdir()`
    |
@@ -50,6 +51,7 @@ import_from.py:13:1: PTH104 `os.rename()` should be replaced by `Path.rename()`
 14 | replace(p)
 15 | rmdir(p)
    |
+   = help: Replace with `Path(...).rename(...)`
 
 import_from.py:14:1: PTH105 `os.replace()` should be replaced by `Path.replace()`
    |
@@ -60,6 +62,7 @@ import_from.py:14:1: PTH105 `os.replace()` should be replaced by `Path.replace()
 15 | rmdir(p)
 16 | remove(p)
    |
+   = help: Replace with `Path(...).replace(...)`
 
 import_from.py:15:1: PTH106 `os.rmdir()` should be replaced by `Path.rmdir()`
    |
@@ -103,6 +106,7 @@ import_from.py:18:1: PTH109 `os.getcwd()` should be replaced by `Path.cwd()`
 19 | b = exists(p)
 20 | bb = expanduser(p)
    |
+   = help: Replace with `Path.cwd()`
 
 import_from.py:19:5: PTH110 `os.path.exists()` should be replaced by `Path.exists()`
    |
@@ -252,6 +256,7 @@ import_from.py:32:1: PTH121 `os.path.samefile()` should be replaced by `Path.sam
 33 | splitext(p)
 34 | with open(p) as fp:
    |
+   = help: Replace with `Path(...).samefile()`
 
 import_from.py:33:1: PTH122 `os.path.splitext()` should be replaced by `Path.suffix`, `Path.stem`, and `Path.parent`
    |
@@ -288,3 +293,36 @@ import_from.py:43:10: PTH123 `open()` should be replaced by `Path.open()`
 43 |     with open(p) as _: ...  # Error
    |          ^^^^ PTH123
    |
+
+import_from.py:53:1: PTH104 `os.rename()` should be replaced by `Path.rename()`
+   |
+51 | file = "file_1.py"
+52 |
+53 | rename(file, "file_2.py")
+   | ^^^^^^ PTH104
+54 |
+55 | rename(
+   |
+   = help: Replace with `Path(...).rename(...)`
+
+import_from.py:55:1: PTH104 `os.rename()` should be replaced by `Path.rename()`
+   |
+53 | rename(file, "file_2.py")
+54 |
+55 | rename(
+   | ^^^^^^ PTH104
+56 |     # commment 1
+57 |     file, # comment 2
+   |
+   = help: Replace with `Path(...).rename(...)`
+
+import_from.py:63:1: PTH104 `os.rename()` should be replaced by `Path.rename()`
+   |
+61 | )
+62 |
+63 | rename(file, "file_2.py", src_dir_fd=None, dst_dir_fd=None)
+   | ^^^^^^ PTH104
+64 |
+65 | rename(file, "file_2.py", src_dir_fd=1)
+   |
+   = help: Replace with `Path(...).rename(...)`

crates/ruff_linter/src/rules/flake8_use_pathlib/snapshots/ruff_linter__rules__flake8_use_pathlib__tests__import_from_as.py.snap

@@ -20,6 +20,7 @@ import_from_as.py:15:6: PTH101 `os.chmod()` should be replaced by `Path.chmod()`
 16 | aaa = xmkdir(p)
 17 | xmakedirs(p)
    |
+   = help: Replace with `Path(...).chmod(...)`
 
 import_from_as.py:16:7: PTH102 `os.mkdir()` should be replaced by `Path.mkdir()`
    |
@@ -50,6 +51,7 @@ import_from_as.py:18:1: PTH104 `os.rename()` should be replaced by `Path.rename(
 19 | xreplace(p)
 20 | xrmdir(p)
    |
+   = help: Replace with `Path(...).rename(...)`
 
 import_from_as.py:19:1: PTH105 `os.replace()` should be replaced by `Path.replace()`
    |
@@ -60,6 +62,7 @@ import_from_as.py:19:1: PTH105 `os.replace()` should be replaced by `Path.replac
 20 | xrmdir(p)
 21 | xremove(p)
    |
+   = help: Replace with `Path(...).replace(...)`
 
 import_from_as.py:20:1: PTH106 `os.rmdir()` should be replaced by `Path.rmdir()`
    |
@@ -103,6 +106,7 @@ import_from_as.py:23:1: PTH109 `os.getcwd()` should be replaced by `Path.cwd()`
 24 | b = xexists(p)
 25 | bb = xexpanduser(p)
    |
+   = help: Replace with `Path.cwd()`
 
 import_from_as.py:24:5: PTH110 `os.path.exists()` should be replaced by `Path.exists()`
    |
@@ -251,6 +255,7 @@ import_from_as.py:37:1: PTH121 `os.path.samefile()` should be replaced by `Path.
    | ^^^^^^^^^ PTH121
 38 | xsplitext(p)
    |
+   = help: Replace with `Path(...).samefile()`
 
 import_from_as.py:38:1: PTH122 `os.path.splitext()` should be replaced by `Path.suffix`, `Path.stem`, and `Path.parent`
    |

crates/ruff_linter/src/rules/flake8_use_pathlib/snapshots/ruff_linter__rules__flake8_use_pathlib__tests__preview_full_name.py.snap

@@ -34,6 +34,7 @@ full_name.py:8:6: PTH101 `os.chmod()` should be replaced by `Path.chmod()`
  9 | aaa = os.mkdir(p)
 10 | os.makedirs(p)
    |
+   = help: Replace with `Path(...).chmod(...)`
 
 full_name.py:9:7: PTH102 `os.mkdir()` should be replaced by `Path.mkdir()`
    |
@@ -64,6 +65,7 @@ full_name.py:11:1: PTH104 `os.rename()` should be replaced by `Path.rename()`
 12 | os.replace(p)
 13 | os.rmdir(p)
    |
+   = help: Replace with `Path(...).rename(...)`
 
 full_name.py:12:1: PTH105 `os.replace()` should be replaced by `Path.replace()`
    |
@@ -74,6 +76,7 @@ full_name.py:12:1: PTH105 `os.replace()` should be replaced by `Path.replace()`
 13 | os.rmdir(p)
 14 | os.remove(p)
    |
+   = help: Replace with `Path(...).replace(...)`
 
 full_name.py:13:1: PTH106 [*] `os.rmdir()` should be replaced by `Path.rmdir()`
    |
@@ -168,6 +171,7 @@ full_name.py:16:1: PTH109 `os.getcwd()` should be replaced by `Path.cwd()`
 17 | b = os.path.exists(p)
 18 | bb = os.path.expanduser(p)
    |
+   = help: Replace with `Path.cwd()`
 
 full_name.py:17:5: PTH110 [*] `os.path.exists()` should be replaced by `Path.exists()`
    |
@@ -470,6 +474,7 @@ full_name.py:30:1: PTH121 `os.path.samefile()` should be replaced by `Path.samef
 31 | os.path.splitext(p)
 32 | with open(p) as fp:
    |
+   = help: Replace with `Path(...).samefile()`
 
 full_name.py:31:1: PTH122 `os.path.splitext()` should be replaced by `Path.suffix`, `Path.stem`, and `Path.parent`
    |
@@ -510,6 +515,7 @@ full_name.py:35:1: PTH109 `os.getcwd()` should be replaced by `Path.cwd()`
 36 | os.path.join(p, *q)
 37 | os.sep.join(p, *q)
    |
+   = help: Replace with `Path.cwd()`
 
 full_name.py:36:1: PTH118 `os.path.join()` should be replaced by `Path.joinpath()`
    |
@@ -578,3 +584,50 @@ full_name.py:71:1: PTH123 `open()` should be replaced by `Path.open()`
 72 |
 73 | # https://github.com/astral-sh/ruff/issues/17693
    |
+
+full_name.py:108:1: PTH109 [*] `os.getcwd()` should be replaced by `Path.cwd()`
+    |
+106 | os.replace("src", "dst", dst_dir_fd=2)
+107 |
+108 | os.getcwd()
+    | ^^^^^^^^^ PTH109
+109 | os.getcwdb()
+    |
+    = help: Replace with `Path.cwd()`
+
+ℹ Safe fix
+1   1   | import os
+2   2   | import os.path
+    3   |+import pathlib
+3   4   | 
+4   5   | p = "/foo"
+5   6   | q = "bar"
+--------------------------------------------------------------------------------
+105 106 | os.replace("src", "dst", src_dir_fd=1)
+106 107 | os.replace("src", "dst", dst_dir_fd=2)
+107 108 | 
+108     |-os.getcwd()
+    109 |+pathlib.Path.cwd()
+109 110 | os.getcwdb()
+
+full_name.py:109:1: PTH109 [*] `os.getcwd()` should be replaced by `Path.cwd()`
+    |
+108 | os.getcwd()
+109 | os.getcwdb()
+    | ^^^^^^^^^^ PTH109
+    |
+    = help: Replace with `Path.cwd()`
+
+ℹ Safe fix
+1   1   | import os
+2   2   | import os.path
+    3   |+import pathlib
+3   4   | 
+4   5   | p = "/foo"
+5   6   | q = "bar"
+--------------------------------------------------------------------------------
+106 107 | os.replace("src", "dst", dst_dir_fd=2)
+107 108 | 
+108 109 | os.getcwd()
+109     |-os.getcwdb()
+    110 |+pathlib.Path.cwd()

crates/ruff_linter/src/rules/flake8_use_pathlib/snapshots/ruff_linter__rules__flake8_use_pathlib__tests__preview_import_as.py.snap

@@ -34,6 +34,7 @@ import_as.py:8:6: PTH101 `os.chmod()` should be replaced by `Path.chmod()`
  9 | aaa = foo.mkdir(p)
 10 | foo.makedirs(p)
    |
+   = help: Replace with `Path(...).chmod(...)`
 
 import_as.py:9:7: PTH102 `os.mkdir()` should be replaced by `Path.mkdir()`
    |
@@ -64,6 +65,7 @@ import_as.py:11:1: PTH104 `os.rename()` should be replaced by `Path.rename()`
 12 | foo.replace(p)
 13 | foo.rmdir(p)
    |
+   = help: Replace with `Path(...).rename(...)`
 
 import_as.py:12:1: PTH105 `os.replace()` should be replaced by `Path.replace()`
    |
@@ -74,6 +76,7 @@ import_as.py:12:1: PTH105 `os.replace()` should be replaced by `Path.replace()`
 13 | foo.rmdir(p)
 14 | foo.remove(p)
    |
+   = help: Replace with `Path(...).replace(...)`
 
 import_as.py:13:1: PTH106 [*] `os.rmdir()` should be replaced by `Path.rmdir()`
    |
@@ -168,6 +171,7 @@ import_as.py:16:1: PTH109 `os.getcwd()` should be replaced by `Path.cwd()`
 17 | b = foo_p.exists(p)
 18 | bb = foo_p.expanduser(p)
    |
+   = help: Replace with `Path.cwd()`
 
 import_as.py:17:5: PTH110 [*] `os.path.exists()` should be replaced by `Path.exists()`
    |
@@ -468,6 +472,7 @@ import_as.py:30:1: PTH121 `os.path.samefile()` should be replaced by `Path.samef
    | ^^^^^^^^^^^^^^ PTH121
 31 | foo_p.splitext(p)
    |
+   = help: Replace with `Path(...).samefile()`
 
 import_as.py:31:1: PTH122 `os.path.splitext()` should be replaced by `Path.suffix`, `Path.stem`, and `Path.parent`
    |

crates/ruff_linter/src/rules/flake8_use_pathlib/snapshots/ruff_linter__rules__flake8_use_pathlib__tests__preview_import_from.py.snap

@@ -35,6 +35,7 @@ import_from.py:10:6: PTH101 `os.chmod()` should be replaced by `Path.chmod()`
 11 | aaa = mkdir(p)
 12 | makedirs(p)
    |
+   = help: Replace with `Path(...).chmod(...)`
 
 import_from.py:11:7: PTH102 `os.mkdir()` should be replaced by `Path.mkdir()`
    |
@@ -65,6 +66,7 @@ import_from.py:13:1: PTH104 `os.rename()` should be replaced by `Path.rename()`
 14 | replace(p)
 15 | rmdir(p)
    |
+   = help: Replace with `Path(...).rename(...)`
 
 import_from.py:14:1: PTH105 `os.replace()` should be replaced by `Path.replace()`
    |
@@ -75,6 +77,7 @@ import_from.py:14:1: PTH105 `os.replace()` should be replaced by `Path.replace()
 15 | rmdir(p)
 16 | remove(p)
    |
+   = help: Replace with `Path(...).replace(...)`
 
 import_from.py:15:1: PTH106 [*] `os.rmdir()` should be replaced by `Path.rmdir()`
    |
@@ -172,6 +175,7 @@ import_from.py:18:1: PTH109 `os.getcwd()` should be replaced by `Path.cwd()`
 19 | b = exists(p)
 20 | bb = expanduser(p)
    |
+   = help: Replace with `Path.cwd()`
 
 import_from.py:19:5: PTH110 [*] `os.path.exists()` should be replaced by `Path.exists()`
    |
@@ -483,6 +487,7 @@ import_from.py:32:1: PTH121 `os.path.samefile()` should be replaced by `Path.sam
 33 | splitext(p)
 34 | with open(p) as fp:
    |
+   = help: Replace with `Path(...).samefile()`
 
 import_from.py:33:1: PTH122 `os.path.splitext()` should be replaced by `Path.suffix`, `Path.stem`, and `Path.parent`
    |
@@ -519,3 +524,95 @@ import_from.py:43:10: PTH123 `open()` should be replaced by `Path.open()`
 43 |     with open(p) as _: ...  # Error
    |          ^^^^ PTH123
    |
+
+import_from.py:53:1: PTH104 [*] `os.rename()` should be replaced by `Path.rename()`
+   |
+51 | file = "file_1.py"
+52 |
+53 | rename(file, "file_2.py")
+   | ^^^^^^ PTH104
+54 |
+55 | rename(
+   |
+   = help: Replace with `Path(...).rename(...)`
+
+ℹ Safe fix
+2  2  | from os import remove, unlink, getcwd, readlink, stat
+3  3  | from os.path import abspath, exists, expanduser, isdir, isfile, islink
+4  4  | from os.path import isabs, join, basename, dirname, samefile, splitext
+   5  |+import pathlib
+5  6  | 
+6  7  | p = "/foo"
+7  8  | q = "bar"
+--------------------------------------------------------------------------------
+50 51 | 
+51 52 | file = "file_1.py"
+52 53 | 
+53    |-rename(file, "file_2.py")
+   54 |+pathlib.Path(file).rename("file_2.py")
+54 55 | 
+55 56 | rename(
+56 57 |     # commment 1
+
+import_from.py:55:1: PTH104 [*] `os.rename()` should be replaced by `Path.rename()`
+   |
+53 | rename(file, "file_2.py")
+54 |
+55 | rename(
+   | ^^^^^^ PTH104
+56 |     # commment 1
+57 |     file, # comment 2
+   |
+   = help: Replace with `Path(...).rename(...)`
+
+ℹ Unsafe fix
+2  2  | from os import remove, unlink, getcwd, readlink, stat
+3  3  | from os.path import abspath, exists, expanduser, isdir, isfile, islink
+4  4  | from os.path import isabs, join, basename, dirname, samefile, splitext
+   5  |+import pathlib
+5  6  | 
+6  7  | p = "/foo"
+7  8  | q = "bar"
+--------------------------------------------------------------------------------
+52 53 | 
+53 54 | rename(file, "file_2.py")
+54 55 | 
+55    |-rename(
+56    |-    # commment 1
+57    |-    file, # comment 2
+58    |-    "file_2.py"
+59    |-    ,
+60    |-    # comment 3
+61    |-)
+   56 |+pathlib.Path(file).rename("file_2.py")
+62 57 | 
+63 58 | rename(file, "file_2.py", src_dir_fd=None, dst_dir_fd=None)
+64 59 | 
+
+import_from.py:63:1: PTH104 [*] `os.rename()` should be replaced by `Path.rename()`
+   |
+61 | )
+62 |
+63 | rename(file, "file_2.py", src_dir_fd=None, dst_dir_fd=None)
+   | ^^^^^^ PTH104
+64 |
+65 | rename(file, "file_2.py", src_dir_fd=1)
+   |
+   = help: Replace with `Path(...).rename(...)`
+
+ℹ Safe fix
+2  2  | from os import remove, unlink, getcwd, readlink, stat
+3  3  | from os.path import abspath, exists, expanduser, isdir, isfile, islink
+4  4  | from os.path import isabs, join, basename, dirname, samefile, splitext
+   5  |+import pathlib
+5  6  | 
+6  7  | p = "/foo"
+7  8  | q = "bar"
+--------------------------------------------------------------------------------
+60 61 |     # comment 3
+61 62 | )
+62 63 | 
+63    |-rename(file, "file_2.py", src_dir_fd=None, dst_dir_fd=None)
+   64 |+pathlib.Path(file).rename("file_2.py")
+64 65 | 
+65 66 | rename(file, "file_2.py", src_dir_fd=1)

crates/ruff_linter/src/rules/flake8_use_pathlib/snapshots/ruff_linter__rules__flake8_use_pathlib__tests__preview_import_from_as.py.snap

@@ -35,6 +35,7 @@ import_from_as.py:15:6: PTH101 `os.chmod()` should be replaced by `Path.chmod()`
 16 | aaa = xmkdir(p)
 17 | xmakedirs(p)
    |
+   = help: Replace with `Path(...).chmod(...)`
 
 import_from_as.py:16:7: PTH102 `os.mkdir()` should be replaced by `Path.mkdir()`
    |
@@ -65,6 +66,7 @@ import_from_as.py:18:1: PTH104 `os.rename()` should be replaced by `Path.rename(
 19 | xreplace(p)
 20 | xrmdir(p)
    |
+   = help: Replace with `Path(...).rename(...)`
 
 import_from_as.py:19:1: PTH105 `os.replace()` should be replaced by `Path.replace()`
    |
@@ -75,6 +77,7 @@ import_from_as.py:19:1: PTH105 `os.replace()` should be replaced by `Path.replac
 20 | xrmdir(p)
 21 | xremove(p)
    |
+   = help: Replace with `Path(...).replace(...)`
 
 import_from_as.py:20:1: PTH106 [*] `os.rmdir()` should be replaced by `Path.rmdir()`
    |
@@ -172,6 +175,7 @@ import_from_as.py:23:1: PTH109 `os.getcwd()` should be replaced by `Path.cwd()`
 24 | b = xexists(p)
 25 | bb = xexpanduser(p)
    |
+   = help: Replace with `Path.cwd()`
 
 import_from_as.py:24:5: PTH110 [*] `os.path.exists()` should be replaced by `Path.exists()`
    |
@@ -481,6 +485,7 @@ import_from_as.py:37:1: PTH121 `os.path.samefile()` should be replaced by `Path.
    | ^^^^^^^^^ PTH121
 38 | xsplitext(p)
    |
+   = help: Replace with `Path(...).samefile()`
 
 import_from_as.py:38:1: PTH122 `os.path.splitext()` should be replaced by `Path.suffix`, `Path.stem`, and `Path.parent`
    |

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

@@ -2,51 +2,6 @@ use ruff_macros::{ViolationMetadata, derive_message_formats};
 
 use crate::Violation;
 
-/// ## What it does
-/// Checks for uses of `os.chmod`.
-///
-/// ## Why is this bad?
-/// `pathlib` offers a high-level API for path manipulation, as compared to
-/// the lower-level API offered by `os`. When possible, using `Path` object
-/// methods such as `Path.chmod()` can improve readability over the `os`
-/// module's counterparts (e.g., `os.chmod()`).
-///
-/// ## Examples
-/// ```python
-/// import os
-///
-/// os.chmod("file.py", 0o444)
-/// ```
-///
-/// Use instead:
-/// ```python
-/// from pathlib import Path
-///
-/// Path("file.py").chmod(0o444)
-/// ```
-///
-/// ## Known issues
-/// While using `pathlib` can improve the readability and type safety of your code,
-/// it can be less performant than the lower-level alternatives that work directly with strings,
-/// especially on older versions of Python.
-///
-/// ## References
-/// - [Python documentation: `Path.chmod`](https://docs.python.org/3/library/pathlib.html#pathlib.Path.chmod)
-/// - [Python documentation: `os.chmod`](https://docs.python.org/3/library/os.html#os.chmod)
-/// - [PEP 428 – The pathlib module – object-oriented filesystem paths](https://peps.python.org/pep-0428/)
-/// - [Correspondence between `os` and `pathlib`](https://docs.python.org/3/library/pathlib.html#correspondence-to-tools-in-the-os-module)
-/// - [Why you should be using pathlib](https://treyhunner.com/2018/12/why-you-should-be-using-pathlib/)
-/// - [No really, pathlib is great](https://treyhunner.com/2019/01/no-really-pathlib-is-great/)
-#[derive(ViolationMetadata)]
-pub(crate) struct OsChmod;
-
-impl Violation for OsChmod {
-    #[derive_message_formats]
-    fn message(&self) -> String {
-        "`os.chmod()` should be replaced by `Path.chmod()`".to_string()
-    }
-}
-
 /// ## What it does
 /// Checks for uses of `os.makedirs`.
 ///
@@ -137,145 +92,6 @@ impl Violation for OsMkdir {
     }
 }
 
-/// ## What it does
-/// Checks for uses of `os.rename`.
-///
-/// ## Why is this bad?
-/// `pathlib` offers a high-level API for path manipulation, as compared to
-/// the lower-level API offered by `os`. When possible, using `Path` object
-/// methods such as `Path.rename()` can improve readability over the `os`
-/// module's counterparts (e.g., `os.rename()`).
-///
-/// ## Examples
-/// ```python
-/// import os
-///
-/// os.rename("old.py", "new.py")
-/// ```
-///
-/// Use instead:
-/// ```python
-/// from pathlib import Path
-///
-/// Path("old.py").rename("new.py")
-/// ```
-///
-/// ## Known issues
-/// While using `pathlib` can improve the readability and type safety of your code,
-/// it can be less performant than the lower-level alternatives that work directly with strings,
-/// especially on older versions of Python.
-///
-/// ## References
-/// - [Python documentation: `Path.rename`](https://docs.python.org/3/library/pathlib.html#pathlib.Path.rename)
-/// - [Python documentation: `os.rename`](https://docs.python.org/3/library/os.html#os.rename)
-/// - [PEP 428 – The pathlib module – object-oriented filesystem paths](https://peps.python.org/pep-0428/)
-/// - [Correspondence between `os` and `pathlib`](https://docs.python.org/3/library/pathlib.html#correspondence-to-tools-in-the-os-module)
-/// - [Why you should be using pathlib](https://treyhunner.com/2018/12/why-you-should-be-using-pathlib/)
-/// - [No really, pathlib is great](https://treyhunner.com/2019/01/no-really-pathlib-is-great/)
-#[derive(ViolationMetadata)]
-pub(crate) struct OsRename;
-
-impl Violation for OsRename {
-    #[derive_message_formats]
-    fn message(&self) -> String {
-        "`os.rename()` should be replaced by `Path.rename()`".to_string()
-    }
-}
-
-/// ## What it does
-/// Checks for uses of `os.replace`.
-///
-/// ## Why is this bad?
-/// `pathlib` offers a high-level API for path manipulation, as compared to
-/// the lower-level API offered by `os`. When possible, using `Path` object
-/// methods such as `Path.replace()` can improve readability over the `os`
-/// module's counterparts (e.g., `os.replace()`).
-///
-/// Note that `os` functions may be preferable if performance is a concern,
-/// e.g., in hot loops.
-///
-/// ## Examples
-/// ```python
-/// import os
-///
-/// os.replace("old.py", "new.py")
-/// ```
-///
-/// Use instead:
-/// ```python
-/// from pathlib import Path
-///
-/// Path("old.py").replace("new.py")
-/// ```
-///
-/// ## Known issues
-/// While using `pathlib` can improve the readability and type safety of your code,
-/// it can be less performant than the lower-level alternatives that work directly with strings,
-/// especially on older versions of Python.
-///
-/// ## References
-/// - [Python documentation: `Path.replace`](https://docs.python.org/3/library/pathlib.html#pathlib.Path.replace)
-/// - [Python documentation: `os.replace`](https://docs.python.org/3/library/os.html#os.replace)
-/// - [PEP 428 – The pathlib module – object-oriented filesystem paths](https://peps.python.org/pep-0428/)
-/// - [Correspondence between `os` and `pathlib`](https://docs.python.org/3/library/pathlib.html#correspondence-to-tools-in-the-os-module)
-/// - [Why you should be using pathlib](https://treyhunner.com/2018/12/why-you-should-be-using-pathlib/)
-/// - [No really, pathlib is great](https://treyhunner.com/2019/01/no-really-pathlib-is-great/)
-#[derive(ViolationMetadata)]
-pub(crate) struct OsReplace;
-
-impl Violation for OsReplace {
-    #[derive_message_formats]
-    fn message(&self) -> String {
-        "`os.replace()` should be replaced by `Path.replace()`".to_string()
-    }
-}
-
-/// ## What it does
-/// Checks for uses of `os.getcwd` and `os.getcwdb`.
-///
-/// ## Why is this bad?
-/// `pathlib` offers a high-level API for path manipulation, as compared to
-/// the lower-level API offered by `os`. When possible, using `Path` object
-/// methods such as `Path.cwd()` can improve readability over the `os`
-/// module's counterparts (e.g., `os.getcwd()`).
-///
-/// ## Examples
-/// ```python
-/// import os
-///
-/// cwd = os.getcwd()
-/// ```
-///
-/// Use instead:
-/// ```python
-/// from pathlib import Path
-///
-/// cwd = Path.cwd()
-/// ```
-///
-/// ## Known issues
-/// While using `pathlib` can improve the readability and type safety of your code,
-/// it can be less performant than the lower-level alternatives that work directly with strings,
-/// especially on older versions of Python.
-///
-/// ## References
-/// - [Python documentation: `Path.cwd`](https://docs.python.org/3/library/pathlib.html#pathlib.Path.cwd)
-/// - [Python documentation: `os.getcwd`](https://docs.python.org/3/library/os.html#os.getcwd)
-/// - [Python documentation: `os.getcwdb`](https://docs.python.org/3/library/os.html#os.getcwdb)
-/// - [PEP 428 – The pathlib module – object-oriented filesystem paths](https://peps.python.org/pep-0428/)
-/// - [Correspondence between `os` and `pathlib`](https://docs.python.org/3/library/pathlib.html#correspondence-to-tools-in-the-os-module)
-/// - [Why you should be using pathlib](https://treyhunner.com/2018/12/why-you-should-be-using-pathlib/)
-/// - [No really, pathlib is great](https://treyhunner.com/2019/01/no-really-pathlib-is-great/)
-#[derive(ViolationMetadata)]
-pub(crate) struct OsGetcwd;
-
-impl Violation for OsGetcwd {
-    #[derive_message_formats]
-    fn message(&self) -> String {
-        "`os.getcwd()` should be replaced by `Path.cwd()`".to_string()
-    }
-}
-
 /// ## What it does
 /// Checks for uses of `os.stat`.
 ///
@@ -393,51 +209,6 @@ pub(crate) enum Joiner {
     Joinpath,
 }
 
-/// ## What it does
-/// Checks for uses of `os.path.samefile`.
-///
-/// ## Why is this bad?
-/// `pathlib` offers a high-level API for path manipulation, as compared to
-/// the lower-level API offered by `os.path`. When possible, using `Path` object
-/// methods such as `Path.samefile()` can improve readability over the `os.path`
-/// module's counterparts (e.g., `os.path.samefile()`).
-///
-/// ## Examples
-/// ```python
-/// import os
-///
-/// os.path.samefile("f1.py", "f2.py")
-/// ```
-///
-/// Use instead:
-/// ```python
-/// from pathlib import Path
-///
-/// Path("f1.py").samefile("f2.py")
-/// ```
-///
-/// ## Known issues
-/// While using `pathlib` can improve the readability and type safety of your code,
-/// it can be less performant than the lower-level alternatives that work directly with strings,
-/// especially on older versions of Python.
-///
-/// ## References
-/// - [Python documentation: `Path.samefile`](https://docs.python.org/3/library/pathlib.html#pathlib.Path.samefile)
-/// - [Python documentation: `os.path.samefile`](https://docs.python.org/3/library/os.path.html#os.path.samefile)
-/// - [PEP 428 – The pathlib module – object-oriented filesystem paths](https://peps.python.org/pep-0428/)
-/// - [Correspondence between `os` and `pathlib`](https://docs.python.org/3/library/pathlib.html#correspondence-to-tools-in-the-os-module)
-/// - [Why you should be using pathlib](https://treyhunner.com/2018/12/why-you-should-be-using-pathlib/)
-/// - [No really, pathlib is great](https://treyhunner.com/2019/01/no-really-pathlib-is-great/)
-#[derive(ViolationMetadata)]
-pub(crate) struct OsPathSamefile;
-
-impl Violation for OsPathSamefile {
-    #[derive_message_formats]
-    fn message(&self) -> String {
-        "`os.path.samefile()` should be replaced by `Path.samefile()`".to_string()
-    }
-}
-
 /// ## What it does
 /// Checks for uses of `os.path.splitext`.
 ///

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

@@ -801,6 +801,7 @@ mod tests {
     #[test_case(Path::new("existing_import.py"))]
     #[test_case(Path::new("multiline_docstring.py"))]
     #[test_case(Path::new("off.py"))]
+    #[test_case(Path::new("whitespace.py"))]
     fn required_import(path: &Path) -> Result<()> {
         let snapshot = format!("required_import_{}", path.to_string_lossy());
         let diagnostics = test_path(

crates/ruff_linter/src/rules/isort/snapshots/ruff_linter__rules__isort__tests__required_import_whitespace.py.snap

@@ -0,0 +1,11 @@
+---
+source: crates/ruff_linter/src/rules/isort/mod.rs
+---
+whitespace.py:1:1: I002 [*] Missing required import: `from __future__ import annotations`
+ℹ Safe fix
+1 1 | # This is a regression test for https://github.com/astral-sh/ruff/issues/19310
+2 2 | # there is a (potentially invisible) unicode formfeed character (000C) between "docstring" and the semicolon
+3   |-"docstring"; print(
+  3 |+"docstring"; from __future__ import annotations; print(
+4 4 |     f"{__doc__=}",
+5 5 | )

crates/ruff_linter/src/rules/pep8_naming/rules/invalid_function_name.rs

@@ -100,7 +100,7 @@ pub(crate) fn invalid_function_name(
         return;
     }
 
-    // Ignore the do_* methods of the http.server.BaseHTTPRequestHandler class
+    // Ignore the do_* methods of the http.server.BaseHTTPRequestHandler class and its subclasses
     if name.starts_with("do_")
         && parent_class.is_some_and(|class| {
             any_base_class(class, semantic, &mut |superclass| {
@@ -108,7 +108,13 @@ pub(crate) fn invalid_function_name(
                 qualified.is_some_and(|name| {
                     matches!(
                         name.segments(),
-                        ["http", "server", "BaseHTTPRequestHandler"]
+                        [
+                            "http",
+                            "server",
+                            "BaseHTTPRequestHandler"
+                                | "CGIHTTPRequestHandler"
+                                | "SimpleHTTPRequestHandler"
+                        ]
                     )
                 })
             })

crates/ruff_linter/src/rules/pep8_naming/snapshots/ruff_linter__rules__pep8_naming__tests__N802_N802.py.snap

@@ -55,3 +55,21 @@ N802.py:84:9: N802 Function name `dont_GET` should be lowercase
    |         ^^^^^^^^ N802
 85 |         pass
    |
+
+N802.py:95:9: N802 Function name `dont_OPTIONS` should be lowercase
+   |
+93 |         pass
+94 |
+95 |     def dont_OPTIONS(self):
+   |         ^^^^^^^^^^^^ N802
+96 |         pass
+   |
+
+N802.py:106:9: N802 Function name `dont_OPTIONS` should be lowercase
+    |
+104 |         pass
+105 |
+106 |     def dont_OPTIONS(self):
+    |         ^^^^^^^^^^^^ N802
+107 |         pass
+    |

crates/ruff_linter/src/rules/perflint/rules/manual_list_comprehension.rs

@@ -406,7 +406,14 @@ fn convert_to_list_extend(
     };
     let target_str = locator.slice(for_stmt.target.range());
     let elt_str = locator.slice(to_append);
-    let generator_str = format!("{elt_str} {for_type} {target_str} in {for_iter_str}{if_str}");
+    let generator_str = if to_append
+        .as_generator_expr()
+        .is_some_and(|generator| !generator.parenthesized)
+    {
+        format!("({elt_str}) {for_type} {target_str} in {for_iter_str}{if_str}")
+    } else {
+        format!("{elt_str} {for_type} {target_str} in {for_iter_str}{if_str}")
+    };
 
     let variable_name = locator.slice(binding);
     let for_loop_inline_comments = comment_strings_in_range(

crates/ruff_linter/src/rules/perflint/snapshots/ruff_linter__rules__perflint__tests__PERF401_PERF401.py.snap

@@ -241,5 +241,27 @@ PERF401.py:280:13: PERF401 Use `list.extend` to create a transformed list
 279 |         if lambda: 0:
 280 |             dst.append(i)
     |             ^^^^^^^^^^^^^ PERF401
+281 |
+282 | def f():
     |
     = help: Replace for loop with list.extend
+
+PERF401.py:286:9: PERF401 Use a list comprehension to create a transformed list
+    |
+284 |     result = []
+285 |     for i in range(3):
+286 |         result.append(x for x in [i])
+    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ PERF401
+287 |
+288 | def f():
+    |
+    = help: Replace for loop with list comprehension
+
+PERF401.py:292:9: PERF401 Use a list comprehension to create a transformed list
+    |
+290 |     result = []
+291 |     for i in range(3):
+292 |         result.append((x for x in [i]))
+    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ PERF401
+    |
+    = help: Replace for loop with list comprehension