Bump version to 0.0.108

.cargo/config.toml

@@ -0,0 +1,2 @@
+[alias]
+dev = "run --package ruff_dev --bin ruff_dev"

.github/workflows/ci.yaml

@@ -14,7 +14,7 @@ jobs:
       - uses: actions/checkout@v3
       - uses: actions-rs/toolchain@v1
         with:
-          toolchain: stable
+          profile: minimal
       - uses: actions/cache@v3
         env:
           cache-name: cache-cargo
@@ -27,7 +27,7 @@ jobs:
             ${{ runner.os }}-build-${{ env.cache-name }}-
             ${{ runner.os }}-build-
             ${{ runner.os }}-
-      - run: cargo build --release
+      - run: cargo build --all --release
 
   cargo_fmt:
     name: "cargo fmt"
@@ -36,7 +36,10 @@ jobs:
       - uses: actions/checkout@v3
       - uses: actions-rs/toolchain@v1
         with:
-          toolchain: stable
+          profile: minimal
+          toolchain: nightly-2022-11-01
+          override: true
+          components: rustfmt
       - uses: actions/cache@v3
         env:
           cache-name: cache-cargo
@@ -49,7 +52,7 @@ jobs:
             ${{ runner.os }}-build-${{ env.cache-name }}-
             ${{ runner.os }}-build-
             ${{ runner.os }}-
-      - run: cargo fmt --check
+      - run: cargo fmt --all --check
 
   cargo_clippy:
     name: "cargo clippy"
@@ -58,7 +61,10 @@ jobs:
       - uses: actions/checkout@v3
       - uses: actions-rs/toolchain@v1
         with:
-          toolchain: stable
+          profile: minimal
+          toolchain: nightly-2022-11-01
+          override: true
+          components: clippy
       - uses: actions/cache@v3
         env:
           cache-name: cache-cargo
@@ -71,7 +77,7 @@ jobs:
             ${{ runner.os }}-build-${{ env.cache-name }}-
             ${{ runner.os }}-build-
             ${{ runner.os }}-
-      - run: cargo clippy -- -D warnings
+      - run: cargo clippy --all -- -D warnings
 
   cargo_test:
     name: "cargo test"
@@ -80,7 +86,9 @@ jobs:
       - uses: actions/checkout@v3
       - uses: actions-rs/toolchain@v1
         with:
-          toolchain: stable
+          profile: minimal
+          toolchain: nightly-2022-11-01
+          override: true
       - uses: actions/cache@v3
         env:
           cache-name: cache-cargo
@@ -93,7 +101,7 @@ jobs:
             ${{ runner.os }}-build-${{ env.cache-name }}-
             ${{ runner.os }}-build-
             ${{ runner.os }}-
-      - run: cargo test
+      - run: cargo test --all
 
   maturin_build:
     name: "maturin build"
@@ -102,7 +110,9 @@ jobs:
       - uses: actions/checkout@v3
       - uses: actions-rs/toolchain@v1
         with:
-          toolchain: stable
+          profile: minimal
+          toolchain: nightly-2022-11-01
+          override: true
       - uses: actions/setup-python@v4
         with:
           python-version: "3.10"

.github/workflows/flake8-to-ruff.yaml

@@ -0,0 +1,298 @@
+name: "[flake8-to-ruff] Release"
+
+on: workflow_dispatch
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
+env:
+  PACKAGE_NAME: flake8-to-ruff
+  CRATE_NAME: flake8_to_ruff
+  PYTHON_VERSION: "3.7" # to build abi3 wheels
+
+jobs:
+  macos-x86_64:
+    runs-on: macos-latest
+    steps:
+      - uses: actions/checkout@v3
+      - uses: actions/setup-python@v4
+        with:
+          python-version: ${{ env.PYTHON_VERSION }}
+          architecture: x64
+      - name: Install Rust toolchain
+        uses: actions-rs/toolchain@v1
+        with:
+          toolchain: stable
+          profile: minimal
+          default: true
+      - name: Build wheels - x86_64
+        uses: messense/maturin-action@v1
+        with:
+          target: x86_64
+          args: --release --out dist --sdist -m ./${{ env.CRATE_NAME }}/Cargo.toml
+          maturin-version: "v0.13.0"
+      - name: Install built wheel - x86_64
+        run: |
+          pip install dist/${{ env.CRATE_NAME }}-*.whl --force-reinstall
+      - name: Upload wheels
+        uses: actions/upload-artifact@v2
+        with:
+          name: wheels
+          path: dist
+  macos-universal:
+    runs-on: macos-latest
+    steps:
+      - uses: actions/checkout@v3
+      - uses: actions/setup-python@v4
+        with:
+          python-version: ${{ env.PYTHON_VERSION }}
+          architecture: x64
+      - name: Install Rust toolchain
+        uses: actions-rs/toolchain@v1
+        with:
+          toolchain: stable
+          profile: minimal
+          default: true
+      - name: Build wheels - universal2
+        uses: messense/maturin-action@v1
+        with:
+          args: --release --universal2 --out dist -m ./${{ env.CRATE_NAME }}/Cargo.toml
+          maturin-version: "v0.13.0"
+      - name: Install built wheel - universal2
+        run: |
+          pip install dist/${{ env.CRATE_NAME }}-*universal2.whl --force-reinstall
+      - name: Upload wheels
+        uses: actions/upload-artifact@v2
+        with:
+          name: wheels
+          path: dist
+
+  windows:
+    runs-on: windows-latest
+    strategy:
+      matrix:
+        target: [x64, x86]
+    steps:
+      - uses: actions/checkout@v3
+      - uses: actions/setup-python@v4
+        with:
+          python-version: ${{ env.PYTHON_VERSION }}
+          architecture: ${{ matrix.target }}
+      - name: Install Rust toolchain
+        uses: actions-rs/toolchain@v1
+        with:
+          toolchain: stable
+          profile: minimal
+          default: true
+      - name: Build wheels
+        uses: messense/maturin-action@v1
+        with:
+          target: ${{ matrix.target }}
+          args: --release --out dist -m ./${{ env.CRATE_NAME }}/Cargo.toml
+          maturin-version: "v0.13.0"
+      - name: Install built wheel
+        shell: bash
+        run: |
+          python -m pip install dist/${{ env.CRATE_NAME }}-*.whl --force-reinstall
+      - name: Upload wheels
+        uses: actions/upload-artifact@v2
+        with:
+          name: wheels
+          path: dist
+
+  linux:
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        target: [x86_64, i686]
+    steps:
+      - uses: actions/checkout@v3
+      - uses: actions/setup-python@v4
+        with:
+          python-version: ${{ env.PYTHON_VERSION }}
+          architecture: x64
+      - name: Build wheels
+        uses: messense/maturin-action@v1
+        with:
+          target: ${{ matrix.target }}
+          manylinux: auto
+          args: --release --out dist -m ./${{ env.CRATE_NAME }}/Cargo.toml
+          maturin-version: "v0.13.0"
+      - name: Install built wheel
+        if: matrix.target == 'x86_64'
+        run: |
+          pip install dist/${{ env.CRATE_NAME }}-*.whl --force-reinstall
+      - name: Upload wheels
+        uses: actions/upload-artifact@v2
+        with:
+          name: wheels
+          path: dist
+
+  linux-cross:
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        target: [aarch64, armv7, s390x, ppc64le, ppc64]
+    steps:
+      - uses: actions/checkout@v3
+      - uses: actions/setup-python@v4
+        with:
+          python-version: ${{ env.PYTHON_VERSION }}
+      - name: Build wheels
+        uses: messense/maturin-action@v1
+        with:
+          target: ${{ matrix.target }}
+          manylinux: auto
+          args: --no-default-features --release --out dist -m ./${{ env.CRATE_NAME }}/Cargo.toml
+          maturin-version: "v0.13.0"
+      - uses: uraimo/run-on-arch-action@v2.0.5
+        if: matrix.target != 'ppc64'
+        name: Install built wheel
+        with:
+          arch: ${{ matrix.target }}
+          distro: ubuntu20.04
+          githubToken: ${{ github.token }}
+          install: |
+            apt-get update
+            apt-get install -y --no-install-recommends python3 python3-pip
+            pip3 install -U pip
+          run: |
+            pip3 install ${{ env.PACKAGE_NAME }} --no-index --find-links dist/ --force-reinstall
+      - name: Upload wheels
+        uses: actions/upload-artifact@v2
+        with:
+          name: wheels
+          path: dist
+
+  musllinux:
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        target:
+          - x86_64-unknown-linux-musl
+          - i686-unknown-linux-musl
+    steps:
+      - uses: actions/checkout@v3
+      - uses: actions/setup-python@v4
+        with:
+          python-version: ${{ env.PYTHON_VERSION }}
+          architecture: x64
+      - name: Build wheels
+        uses: messense/maturin-action@v1
+        with:
+          target: ${{ matrix.target }}
+          manylinux: musllinux_1_2
+          args: --release --out dist -m ./${{ env.CRATE_NAME }}/Cargo.toml
+          maturin-version: "v0.13.0"
+      - name: Install built wheel
+        if: matrix.target == 'x86_64-unknown-linux-musl'
+        uses: addnab/docker-run-action@v3
+        with:
+          image: alpine:latest
+          options: -v ${{ github.workspace }}:/io -w /io
+          run: |
+            apk add py3-pip
+            pip3 install ${{ env.PACKAGE_NAME }} --no-index --find-links /io/dist/ --force-reinstall
+      - name: Upload wheels
+        uses: actions/upload-artifact@v2
+        with:
+          name: wheels
+          path: dist
+
+  musllinux-cross:
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        platform:
+          - target: aarch64-unknown-linux-musl
+            arch: aarch64
+          - target: armv7-unknown-linux-musleabihf
+            arch: armv7
+    steps:
+      - uses: actions/checkout@v3
+      - uses: actions/setup-python@v4
+        with:
+          python-version: ${{ env.PYTHON_VERSION }}
+      - name: Build wheels
+        uses: messense/maturin-action@v1
+        with:
+          target: ${{ matrix.platform.target }}
+          manylinux: musllinux_1_2
+          args: --release --out dist -m ./${{ env.CRATE_NAME }}/Cargo.toml
+          maturin-version: "v0.13.0"
+      - uses: uraimo/run-on-arch-action@master
+        name: Install built wheel
+        with:
+          arch: ${{ matrix.platform.arch }}
+          distro: alpine_latest
+          githubToken: ${{ github.token }}
+          install: |
+            apk add py3-pip
+          run: |
+            pip3 install ${{ env.PACKAGE_NAME }} --no-index --find-links dist/ --force-reinstall
+      - name: Upload wheels
+        uses: actions/upload-artifact@v2
+        with:
+          name: wheels
+          path: dist
+
+  pypy:
+    runs-on: ${{ matrix.os }}
+    strategy:
+      matrix:
+        os: [ubuntu-latest, macos-latest]
+        target: [x86_64, aarch64]
+        python-version:
+          - "3.7"
+          - "3.8"
+          - "3.9"
+        exclude:
+          - os: macos-latest
+            target: aarch64
+    steps:
+      - uses: actions/checkout@v3
+      - uses: actions/setup-python@v4
+        with:
+          python-version: pypy${{ matrix.python-version }}
+      - name: Build wheels
+        uses: messense/maturin-action@v1
+        with:
+          maturin-version: "v0.13.0"
+          target: ${{ matrix.target }}
+          manylinux: auto
+          args: --release --out dist -i pypy${{ matrix.python-version }} -m ./${{ env.CRATE_NAME }}/Cargo.toml
+      - name: Install built wheel
+        if: matrix.target == 'x86_64'
+        run: |
+          pip install dist/${{ env.CRATE_NAME }}-*.whl --force-reinstall
+      - name: Upload wheels
+        uses: actions/upload-artifact@v2
+        with:
+          name: wheels
+          path: dist
+
+  release:
+    name: Release
+    runs-on: ubuntu-latest
+    needs:
+      - macos-universal
+      - macos-x86_64
+      - windows
+      - linux
+      - linux-cross
+      - musllinux
+      - musllinux-cross
+      - pypy
+    steps:
+      - uses: actions/download-artifact@v2
+        with:
+          name: wheels
+      - uses: actions/setup-python@v4
+      - name: Publish to PyPi
+        env:
+          TWINE_USERNAME: __token__
+          TWINE_PASSWORD: ${{ secrets.FLAKE8_TO_RUFF_TOKEN }}
+        run: |
+          pip install --upgrade twine
+          twine upload --skip-existing *

.github/workflows/ruff.yaml

@@ -1,8 +1,6 @@
-name: Release
+name: "[ruff] Release"
 
 on:
-  pull_request:
-    branches: [main]
   create:
     tags:
       - v*
@@ -297,7 +295,7 @@ jobs:
       - name: Publish to PyPi
         env:
           TWINE_USERNAME: __token__
-          TWINE_PASSWORD: ${{ secrets.PYPI_TOKEN }}
+          TWINE_PASSWORD: ${{ secrets.RUFF_TOKEN }}
         run: |
           pip install --upgrade twine
           twine upload --skip-existing *

.pre-commit-config.yaml

@@ -1,6 +1,6 @@
 repos:
   - repo: https://github.com/charliermarsh/ruff-pre-commit
-    rev: v0.0.89
+    rev: v0.0.108
     hooks:
       - id: ruff
 

CONTRIBUTING.md

@@ -1,17 +1,17 @@
-# Contributing to ruff
+# Contributing to Ruff
 
-Welcome! We're happy to have you here. Thank you in advance for your contribution to ruff.
+Welcome! We're happy to have you here. Thank you in advance for your contribution to Ruff.
 
 ## The basics
 
-ruff welcomes contributions in the form of Pull Requests. For small changes (e.g., bug fixes), feel
+Ruff welcomes contributions in the form of Pull Requests. For small changes (e.g., bug fixes), feel
 free to submit a PR. For larger changes (e.g., new lint rules, new functionality, new configuration
 options), consider submitting an [Issue](https://github.com/charliermarsh/ruff/issues) outlining
 your proposed change.
 
 ### Prerequisites
 
-ruff is written in Rust (1.63.0). You'll need to install the
+Ruff is written in Rust. You'll need to install the
 [Rust toolchain](https://www.rust-lang.org/tools/install) for development.
 
 You'll also need [Insta](https://insta.rs/docs/) to update snapshot tests:
@@ -22,7 +22,7 @@ cargo install cargo-insta
 
 ### Development
 
-After cloning the repository, run ruff locally with:
+After cloning the repository, run Ruff locally with:
 
 ```shell
 cargo run resources/test/fixtures --no-cache
@@ -32,9 +32,9 @@ Prior to opening a pull request, ensure that your code has been auto-formatted,
 both the lint and test validation checks:
 
 ```shell
-cargo fmt     # Auto-formatting...
-cargo clippy  # Linting...
-cargo test    # Testing...
+cargo +nightly fmt --all     # Auto-formatting...
+cargo +nightly clippy --all  # Linting...
+cargo +nightly test --all    # Testing...
 ```
 
 These checks will run on GitHub Actions when you open your Pull Request, but running them locally
@@ -45,12 +45,13 @@ prior to merging.
 
 ### Example: Adding a new lint rule
 
-There are three phases to adding a new lint rule:
+There are four phases to adding a new lint rule:
 
 1. Define the rule in `src/checks.rs`.
-2. Define the _logic_ for triggering the rule in `src/check_ast.rs` (for AST-based checks)
-   or `src/check_lines.rs` (for text-based checks).
+2. Define the _logic_ for triggering the rule in `src/check_ast.rs` (for AST-based checks),
+   `src/check_tokens.rs` (for token-based checks), or `src/check_lines.rs` (for text-based checks).
 3. Add a test fixture.
+4. Update the generated files (documentation and generated code).
 
 To define the rule, open up `src/checks.rs`. You'll need to define both a `CheckCode` and
 `CheckKind`. As an example, you can grep for `E402` and `ModuleImportNotAtTopOfFile`, and follow the
@@ -58,37 +59,33 @@ pattern implemented therein.
 
 To trigger the rule, you'll likely want to augment the logic in `src/check_ast.rs`, which defines
 the Python AST visitor, responsible for iterating over the abstract syntax tree and collecting
-lint-rule violations as it goes. Grep for the `Check::new` invocations to understand how other,
-similar rules are implemented.
+lint-rule violations as it goes. If you need to inspect the AST, you can run `cargo dev print-ast`
+with a Python file. Grep for the `Check::new` invocations to understand how other, similar rules
+are implemented.
 
 To add a test fixture, create a file under `resources/test/fixtures`, named to match the `CheckCode`
 you defined earlier (e.g., `E402.py`). This file should contain a variety of violations and
-non-violations designed to evaluate and demonstrate the behavior of your lint rule. Run ruff locally
-with (e.g.) `cargo run resources/test/fixtures/E402.py`. Once you're satisfied with the output,
-codify the behavior as a snapshot test by adding a new function to the `mod tests` section of
-`src/linter.rs`, like so:
+non-violations designed to evaluate and demonstrate the behavior of your lint rule. Run Ruff locally
+with (e.g.) `cargo run resources/test/fixtures/E402.py --no-cache`. Once you're satisfied with the
+output, codify the behavior as a snapshot test by adding a new `testcase` macro to the `mod tests`
+section of `src/linter.rs`, like so:
 
 ```rust
-#[test]
-fn e402() -> Result<()> {
-    let mut checks = check_path(
-        Path::new("./resources/test/fixtures/E402.py"),
-        &settings::Settings::for_rule(CheckCode::E402),
-        &fixer::Mode::Generate,
-    )?;
-    checks.sort_by_key(|check| check.location);
-    insta::assert_yaml_snapshot!(checks);
-    Ok(())
-}
+#[test_case(CheckCode::A001, Path::new("A001.py"); "A001")]
+...
 ```
 
 Then, run `cargo test`. Your test will fail, but you'll be prompted to follow-up with
 `cargo insta review`. Accept the generated snapshot, then commit the snapshot file alongside the
 rest of your changes.
 
+Finally, to update the documentation, run `cargo dev generate-rules-table` from the repo root. To
+update the generated prefix map, run `cargo dev generate-check-code-prefix`. Both of these commands
+should be run whenever a new check is added to the codebase.
+
 ### Example: Adding a new configuration option
 
-ruff's user-facing settings live in two places: first, the command-line options defined with
+Ruff's user-facing settings live in two places: first, the command-line options defined with
 [clap](https://docs.rs/clap/latest/clap/) via the `Cli` struct in `src/main.rs`; and second, the
 `Config` struct defined `src/pyproject.rs`, which is responsible for extracting user-defined
 settings from a `pyproject.toml` file.
@@ -103,9 +100,9 @@ acceptable unused variables (e.g., `_`).
 
 ## Release process
 
-As of now, ruff has an ad hoc release process: releases are cut with high frequency via GitHub
+As of now, Ruff has an ad hoc release process: releases are cut with high frequency via GitHub
 Actions, which automatically generates the appropriate wheels across architectures and publishes
 them to [PyPI](https://pypi.org/project/ruff/).
 
-ruff follows the [semver](https://semver.org/) versioning standard. However, as pre-1.0 software,
+Ruff follows the [semver](https://semver.org/) versioning standard. However, as pre-1.0 software,
 even patch releases may contain [non-backwards-compatible changes](https://semver.org/#spec-item-4).

Cargo.lock

@@ -37,6 +37,12 @@ dependencies = [
  "libc",
 ]
 
+[[package]]
+name = "anes"
+version = "0.1.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4b46cbb362ab8752921c97e041f5e366ee6297bd428a31275b9fcf1e380f7299"
+
 [[package]]
 name = "annotate-snippets"
 version = "0.6.1"
@@ -368,6 +374,12 @@ version = "1.2.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "c1db59621ec70f09c5e9b597b220c7a2b43611f4710dc03ceb8748637775692c"
 
+[[package]]
+name = "cast"
+version = "0.3.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "37b2a672a2cb129a2e41c10b1224bb368f9f37a2b16b612598138befd7b37eb5"
+
 [[package]]
 name = "cc"
 version = "1.0.73"
@@ -416,6 +428,45 @@ version = "1.4.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "fff857943da45f546682664a79488be82e69e43c1a7a2307679ab9afb3a66d2e"
 
+[[package]]
+name = "ciborium"
+version = "0.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b0c137568cc60b904a7724001b35ce2630fd00d5d84805fbb608ab89509d788f"
+dependencies = [
+ "ciborium-io",
+ "ciborium-ll",
+ "serde",
+]
+
+[[package]]
+name = "ciborium-io"
+version = "0.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "346de753af073cc87b52b2083a506b38ac176a44cfb05497b622e27be899b369"
+
+[[package]]
+name = "ciborium-ll"
+version = "0.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "213030a2b5a4e0c0892b6652260cf6ccac84827b83a85a534e178e3906c4cf1b"
+dependencies = [
+ "ciborium-io",
+ "half",
+]
+
+[[package]]
+name = "clap"
+version = "3.2.23"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "71655c45cb9845d3270c9d6df84ebe72b4dad3c2ba3f7023ad47c144e4e473a5"
+dependencies = [
+ "bitflags",
+ "clap_lex 0.2.4",
+ "indexmap",
+ "textwrap 0.16.0",
+]
+
 [[package]]
 name = "clap"
 version = "4.0.15"
@@ -425,7 +476,7 @@ dependencies = [
  "atty",
  "bitflags",
  "clap_derive",
- "clap_lex",
+ "clap_lex 0.3.0",
  "once_cell",
  "strsim",
  "termcolor",
@@ -444,6 +495,15 @@ dependencies = [
  "syn",
 ]
 
+[[package]]
+name = "clap_lex"
+version = "0.2.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2850f2f5a82cbf437dd5af4d49848fbdfc27c157c3d010345776f952765261c5"
+dependencies = [
+ "os_str_bytes",
+]
+
 [[package]]
 name = "clap_lex"
 version = "0.3.0"
@@ -511,6 +571,12 @@ dependencies = [
  "cache-padded",
 ]
 
+[[package]]
+name = "configparser"
+version = "3.0.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5458d9d1a587efaf5091602c59d299696a3877a439c8f6d461a2d3cce11df87a"
+
 [[package]]
 name = "console"
 version = "0.15.2"
@@ -548,6 +614,42 @@ dependencies = [
  "cfg-if 1.0.0",
 ]
 
+[[package]]
+name = "criterion"
+version = "0.4.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e7c76e09c1aae2bc52b3d2f29e13c6572553b30c4aa1b8a49fd70de6412654cb"
+dependencies = [
+ "anes",
+ "atty",
+ "cast",
+ "ciborium",
+ "clap 3.2.23",
+ "criterion-plot",
+ "itertools",
+ "lazy_static",
+ "num-traits",
+ "oorandom",
+ "plotters",
+ "rayon",
+ "regex",
+ "serde",
+ "serde_derive",
+ "serde_json",
+ "tinytemplate",
+ "walkdir",
+]
+
+[[package]]
+name = "criterion-plot"
+version = "0.5.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6b50826342786a51a89e2da3a28f1c32b06e387201bc2d19791f622c673706b1"
+dependencies = [
+ "cast",
+ "itertools",
+]
+
 [[package]]
 name = "crossbeam-channel"
 version = "0.5.6"
@@ -816,6 +918,21 @@ version = "0.4.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "0ce7134b9999ecaf8bcd65542e436736ef32ddca1b3e06094cb6ec5755203b80"
 
+[[package]]
+name = "flake8-to-ruff"
+version = "0.0.108-dev.0"
+dependencies = [
+ "anyhow",
+ "clap 4.0.15",
+ "configparser",
+ "once_cell",
+ "regex",
+ "ruff",
+ "serde",
+ "serde_json",
+ "toml",
+]
+
 [[package]]
 name = "flate2"
 version = "1.0.24"
@@ -1041,6 +1158,12 @@ dependencies = [
  "wasm-bindgen",
 ]
 
+[[package]]
+name = "half"
+version = "1.8.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "eabb4a44450da02c90444cf74558da904edde8fb4e9035a9a6a4e15445af0bd7"
+
 [[package]]
 name = "hashbrown"
 version = "0.12.3"
@@ -1571,6 +1694,12 @@ version = "1.15.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "e82dad04139b71a90c080c8463fe0dc7902db5192d939bd0950f074d014339e1"
 
+[[package]]
+name = "oorandom"
+version = "11.1.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0ab1bc2a289d34bd04a330323ac98a1b4bc82c9d9fcb1e66b63caa84da26b575"
+
 [[package]]
 name = "opaque-debug"
 version = "0.2.3"
@@ -1779,6 +1908,34 @@ version = "0.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "8b870d8c151b6f2fb93e84a13146138f05d02ed11c7e7c54f8826aaaf7c9f184"
 
+[[package]]
+name = "plotters"
+version = "0.3.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2538b639e642295546c50fcd545198c9d64ee2a38620a628724a3b266d5fbf97"
+dependencies = [
+ "num-traits",
+ "plotters-backend",
+ "plotters-svg",
+ "wasm-bindgen",
+ "web-sys",
+]
+
+[[package]]
+name = "plotters-backend"
+version = "0.3.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "193228616381fecdc1224c62e96946dfbc73ff4384fba576e052ff8c1bea8142"
+
+[[package]]
+name = "plotters-svg"
+version = "0.3.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f9a81d2759aae1dae668f783c308bc5c8ebd191ff4184aaa1b37f65a6ae5a56f"
+dependencies = [
+ "plotters-backend",
+]
+
 [[package]]
 name = "polling"
 version = "2.3.0"
@@ -2052,20 +2209,30 @@ dependencies = [
  "winapi 0.3.9",
 ]
 
+[[package]]
+name = "ropey"
+version = "1.5.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "bbd22239fafefc42138ca5da064f3c17726a80d2379d817a3521240e78dd0064"
+dependencies = [
+ "smallvec",
+ "str_indices",
+]
+
 [[package]]
 name = "ruff"
-version = "0.0.89"
+version = "0.0.108"
 dependencies = [
  "anyhow",
  "assert_cmd",
  "bincode",
  "cacache",
  "chrono",
- "clap",
+ "clap 4.0.15",
  "clearscreen",
- "codegen",
  "colored",
  "common-path",
+ "criterion",
  "dirs 4.0.0",
  "fern",
  "filetime",
@@ -2081,6 +2248,7 @@ dependencies = [
  "path-absolutize",
  "rayon",
  "regex",
+ "ropey",
  "rustpython-ast",
  "rustpython-common",
  "rustpython-parser",
@@ -2089,13 +2257,29 @@ dependencies = [
  "strum",
  "strum_macros",
  "test-case",
- "textwrap",
+ "textwrap 0.15.1",
  "titlecase",
  "toml",
  "update-informer",
  "walkdir",
 ]
 
+[[package]]
+name = "ruff_dev"
+version = "0.0.108"
+dependencies = [
+ "anyhow",
+ "clap 4.0.15",
+ "codegen",
+ "itertools",
+ "ruff",
+ "rustpython-ast",
+ "rustpython-common",
+ "rustpython-parser",
+ "strum",
+ "strum_macros",
+]
+
 [[package]]
 name = "rustls"
 version = "0.20.6"
@@ -2111,7 +2295,7 @@ dependencies = [
 [[package]]
 name = "rustpython-ast"
 version = "0.1.0"
-source = "git+https://github.com/charliermarsh/RustPython.git?rev=1b253a12705f84972cd76e8dc1cdaaccb233e5a5#1b253a12705f84972cd76e8dc1cdaaccb233e5a5"
+source = "git+https://github.com/RustPython/RustPython.git?rev=27bf82a2251d7e6ac6cd75e6ad51be12a53d84bb#27bf82a2251d7e6ac6cd75e6ad51be12a53d84bb"
 dependencies = [
  "num-bigint",
  "rustpython-common",
@@ -2121,7 +2305,7 @@ dependencies = [
 [[package]]
 name = "rustpython-common"
 version = "0.0.0"
-source = "git+https://github.com/charliermarsh/RustPython.git?rev=1b253a12705f84972cd76e8dc1cdaaccb233e5a5#1b253a12705f84972cd76e8dc1cdaaccb233e5a5"
+source = "git+https://github.com/RustPython/RustPython.git?rev=27bf82a2251d7e6ac6cd75e6ad51be12a53d84bb#27bf82a2251d7e6ac6cd75e6ad51be12a53d84bb"
 dependencies = [
  "ascii",
  "cfg-if 1.0.0",
@@ -2144,7 +2328,7 @@ dependencies = [
 [[package]]
 name = "rustpython-compiler-core"
 version = "0.1.2"
-source = "git+https://github.com/charliermarsh/RustPython.git?rev=1b253a12705f84972cd76e8dc1cdaaccb233e5a5#1b253a12705f84972cd76e8dc1cdaaccb233e5a5"
+source = "git+https://github.com/RustPython/RustPython.git?rev=27bf82a2251d7e6ac6cd75e6ad51be12a53d84bb#27bf82a2251d7e6ac6cd75e6ad51be12a53d84bb"
 dependencies = [
  "bincode",
  "bitflags",
@@ -2161,7 +2345,7 @@ dependencies = [
 [[package]]
 name = "rustpython-parser"
 version = "0.1.2"
-source = "git+https://github.com/charliermarsh/RustPython.git?rev=1b253a12705f84972cd76e8dc1cdaaccb233e5a5#1b253a12705f84972cd76e8dc1cdaaccb233e5a5"
+source = "git+https://github.com/RustPython/RustPython.git?rev=27bf82a2251d7e6ac6cd75e6ad51be12a53d84bb#27bf82a2251d7e6ac6cd75e6ad51be12a53d84bb"
 dependencies = [
  "ahash",
  "anyhow",
@@ -2401,6 +2585,12 @@ version = "1.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "a2eb9349b6444b326872e140eb1cf5e7c522154d69e7a0ffb0fb81c06b37543f"
 
+[[package]]
+name = "str_indices"
+version = "0.4.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9d9199fa80c817e074620be84374a520062ebac833f358d74b37060ce4a0f2c0"
+
 [[package]]
 name = "string_cache"
 version = "0.8.4"
@@ -2549,6 +2739,12 @@ dependencies = [
  "unicode-width",
 ]
 
+[[package]]
+name = "textwrap"
+version = "0.16.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "222a222a5bfe1bba4a77b45ec488a741b3cb8872e5e499451fd7d0129c9c7c3d"
+
 [[package]]
 name = "thiserror"
 version = "1.0.37"
@@ -2589,6 +2785,16 @@ dependencies = [
  "crunchy",
 ]
 
+[[package]]
+name = "tinytemplate"
+version = "1.2.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "be4d6b5f19ff7664e8c98d03e2139cb510db9b0a60b55f8e8709b689d939b6bc"
+dependencies = [
+ "serde",
+ "serde_json",
+]
+
 [[package]]
 name = "tinyvec"
 version = "1.6.0"

Cargo.toml

@@ -1,6 +1,12 @@
+[workspace]
+members = [
+  "flake8_to_ruff",
+  "ruff_dev",
+]
+
 [package]
 name = "ruff"
-version = "0.0.89"
+version = "0.0.108"
 edition = "2021"
 
 [lib]
@@ -26,9 +32,10 @@ once_cell = { version = "1.13.1" }
 path-absolutize = { version = "3.0.14", features = ["once_cell_cache", "use_unix_paths_on_wasm"] }
 rayon = { version = "1.5.3" }
 regex = { version = "1.6.0" }
-rustpython-ast = { features = ["unparse"], git = "https://github.com/charliermarsh/RustPython.git", rev = "1b253a12705f84972cd76e8dc1cdaaccb233e5a5" }
-rustpython-common = { git = "https://github.com/charliermarsh/RustPython.git", rev = "1b253a12705f84972cd76e8dc1cdaaccb233e5a5" }
-rustpython-parser = { features = ["lalrpop"], git = "https://github.com/charliermarsh/RustPython.git", rev = "1b253a12705f84972cd76e8dc1cdaaccb233e5a5" }
+ropey = { version = "1.5.0" }
+rustpython-ast = { features = ["unparse"], git = "https://github.com/RustPython/RustPython.git", rev = "27bf82a2251d7e6ac6cd75e6ad51be12a53d84bb" }
+rustpython-common = { git = "https://github.com/RustPython/RustPython.git", rev = "27bf82a2251d7e6ac6cd75e6ad51be12a53d84bb" }
+rustpython-parser = { features = ["lalrpop"], git = "https://github.com/RustPython/RustPython.git", rev = "27bf82a2251d7e6ac6cd75e6ad51be12a53d84bb" }
 serde = { version = "1.0.143", features = ["derive"] }
 serde_json = { version = "1.0.83" }
 strum = { version = "0.24.1", features = ["strum_macros"] }
@@ -50,7 +57,7 @@ getrandom = { version = "0.2.7", features = ["js"] }
 
 [dev-dependencies]
 assert_cmd = { version = "2.0.4" }
-codegen = { version = "0.2.0" }
+criterion = { version = "0.4.0" }
 insta = { version = "1.19.1", features = ["yaml"] }
 test-case = { version = "2.2.2" }
 
@@ -69,3 +76,7 @@ opt-level = 3
 
 [profile.dev.package.similar]
 opt-level = 3
+
+[[bench]]
+name = "source_code_locator"
+harness = false

README.md

@@ -15,15 +15,15 @@ An extremely fast Python linter, written in Rust.
   <i>Linting the CPython codebase from scratch.</i>
 </p>
 
-- ⚡️ 10-100x faster than existing linters
-- 🐍 Installable via `pip`
-- 🤝 Python 3.10 compatibility
-- 🛠️ `pyproject.toml` support
-- 📦 [ESLint](https://eslint.org/docs/latest/user-guide/command-line-interface#caching)-inspired cache support
-- 🔧 [ESLint](https://eslint.org/docs/latest/user-guide/command-line-interface#--fix)-inspired autofix support (e.g., automatically remove unused imports)
-- 👀 [TypeScript](https://www.typescriptlang.org/docs/handbook/configuring-watch.html)-inspired `--watch` support, for continuous file monitoring
-- ⚖️ [Near-parity](#how-does-ruff-compare-to-flake8) with the built-in Flake8 rule set
-- 🔌 Native re-implementations of popular Flake8 plugins, like [`flake8-docstrings`](https://pypi.org/project/flake8-docstrings/) ([`pydocstyle`](https://pypi.org/project/pydocstyle/))
+- ⚡️  10-100x faster than existing linters
+- 🐍  Installable via `pip`
+- 🤝  Python 3.10 compatibility
+- 🛠️  `pyproject.toml` support
+- 📦  Built-in caching, to avoid re-analyzing unchanged files
+- 🔧  `--fix` support, for automatic error correction (e.g., automatically remove unused imports)
+- 👀  `--watch` support, for continuous file monitoring
+- ⚖️  [Near-parity](#how-does-ruff-compare-to-flake8) with the built-in Flake8 rule set
+- 🔌  Native re-implementations of popular Flake8 plugins, like [`flake8-docstrings`](https://pypi.org/project/flake8-docstrings/) ([`pydocstyle`](https://pypi.org/project/pydocstyle/))
 
 Ruff aims to be orders of magnitude faster than alternative tools while integrating more
 functionality behind a single, common interface. Ruff can be used to replace Flake8 (plus a variety
@@ -31,6 +31,13 @@ of plugins), [`pydocstyle`](https://pypi.org/project/pydocstyle/), [`yesqa`](htt
 and even a subset of [`pyupgrade`](https://pypi.org/project/pyupgrade/) and [`autoflake`](https://pypi.org/project/autoflake/)
 all while executing tens or hundreds of times faster than any individual tool.
 
+(Coming from Flake8? Try [`flake8-to-ruff`](https://pypi.org/project/flake8-to-ruff/) to
+automatically convert your existing configuration.)
+
+Ruff is actively developed and used in major open-source projects
+like [Zulip](https://github.com/zulip/zulip), [pydantic](https://github.com/pydantic/pydantic),
+and [Saleor](https://github.com/saleor/saleor).
+
 Read the [launch blog post](https://notes.crmarsh.com/python-tooling-could-be-much-much-faster).
 
 ## Table of Contents
@@ -38,13 +45,26 @@ Read the [launch blog post](https://notes.crmarsh.com/python-tooling-could-be-mu
 1. [Installation and Usage](#installation-and-usage)
 2. [Configuration](#configuration)
 3. [Supported Rules](#supported-rules)
-4. [Editor Integrations](#editor-integrations)
-5. [FAQ](#faq)
-6. [Development](#development)
-7. [Releases](#releases)
-8. [Benchmarks](#benchmarks)
-9. [License](#license)
-10. [Contributing](#contributing)
+   1. [Pyflakes](#pyflakes)
+   2. [pycodestyle](#pycodestyle)
+   3. [pydocstyle](#pydocstyle)
+   4. [pyupgrade](#pyupgrade)
+   5. [pep8-naming](#pep8-naming)
+   6. [flake8-comprehensions](#flake8-comprehensions)
+   7. [flake8-bugbear](#flake8-bugbear)
+   8. [flake8-builtins](#flake8-builtins)
+   9. [flake8-print](#flake8-print)
+   10. [flake8-quotes](#flake8-quotes)
+   11. [flake8-annotations](#flake8-annotations)
+   12. [Ruff-specific rules](#ruff-specific-rules)
+   13. [Meta rules](#meta-rules)
+5. [Editor Integrations](#editor-integrations)
+6. [FAQ](#faq)
+7. [Development](#development)
+8. [Releases](#releases)
+9. [Benchmarks](#benchmarks)
+10. [License](#license)
+11. [Contributing](#contributing)
 
 ## Installation and Usage
 
@@ -77,7 +97,7 @@ Ruff also works with [pre-commit](https://pre-commit.com):
 ```yaml
 repos:
   - repo: https://github.com/charliermarsh/ruff-pre-commit
-    rev: v0.0.89
+    rev: v0.0.108
     hooks:
       - id: ruff
 ```
@@ -87,26 +107,68 @@ _Note: prior to `v0.0.86`, `ruff-pre-commit` used `lint` (rather than `ruff`) as
 
 ## Configuration
 
-Ruff is configurable both via `pyproject.toml` and the command line.
-
-For example, you could configure Ruff to only enforce a subset of rules with:
+Ruff is configurable both via `pyproject.toml` and the command line. If left unspecified, the
+default configuration is equivalent to:
 
 ```toml
 [tool.ruff]
 line-length = 88
+
+# Enable Flake's "E" and "F" codes by default.
 select = ["E", "F"]
-ignore = ["E501"]
-per-file-ignores = [
-    "__init__.py:F401",
-    "path/to/file.py:F401"
+ignore = []
+
+# Exclude a variety of commonly ignored directories.
+exclude = [
+    ".bzr",
+    ".direnv",
+    ".eggs",
+    ".git",
+    ".hg",
+    ".mypy_cache",
+    ".nox",
+    ".pants.d",
+    ".ruff_cache",
+    ".svn",
+    ".tox",
+    ".venv",
+    "__pypackages__",
+    "_build",
+    "buck-out",
+    "build",
+    "dist",
+    "node_modules",
+    "venv",
 ]
+per-file-ignores = {}
+
+# Allow unused variables when underscore-prefixed.
+dummy-variable-rgx = "^(_+|(_+[a-zA-Z0-9_]*[a-zA-Z0-9]+?))$"
+
+# Assume Python 3.10.
+target-version = "py310"
+```
+
+As an example, the following would configure Ruff to (1) avoid checking for line-length
+violations (`E501`) and (2) ignore unused import rules in `__init__.py` files:
+
+```toml
+[tool.ruff]
+select = ["E", "F"]
+
+# Never enforce `E501`.
+ignore = ["E501"]
+
+# Ignore `F401` violations in any `__init__.py` file, and in `path/to/file.py`.
+per-file-ignores = {"__init__.py" = ["F401"], "path/to/file.py" = ["F401"]}
 ```
 
 Plugin configurations should be expressed as subsections, e.g.:
 
 ```toml
 [tool.ruff]
-line-length = 88
+# Add "Q" to the list of enabled codes.
+select = ["E", "F", "Q"]
 
 [tool.ruff.flake8-quotes]
 docstring-quotes = "double"
@@ -134,12 +196,14 @@ Options:
   -v, --verbose
           Enable verbose logging
   -q, --quiet
+          Only log errors
+  -s, --silent
           Disable all logging (but still exit with status code "1" upon detecting errors)
   -e, --exit-zero
           Exit with status code "0", even upon detecting errors
   -w, --watch
           Run in watch mode by re-running whenever files change
-  -f, --fix
+      --fix
           Attempt to automatically fix lint errors
   -n, --no-cache
           Disable cache reads
@@ -234,12 +298,19 @@ add `noqa` directives to all failing lines, with the appropriate error codes.**
 
 ## Supported Rules
 
+Regardless of the rule's origin, Ruff re-implements every rule in Rust as a first-party feature.
+
 By default, Ruff enables all `E` and `F` error codes, which correspond to those built-in to Flake8.
 
 The 🛠 emoji indicates that a rule is automatically fixable by the `--fix` command-line option.
 
+<!-- Sections automatically generated by `cargo dev generate-rules-table`. -->
+<!-- Begin auto-generated sections. -->
+
 ### Pyflakes
 
+For more, see [Pyflakes](https://pypi.org/project/pyflakes/2.5.0/) on PyPI.
+
 | Code | Name | Message | Fix |
 | ---- | ---- | ------- | --- |
 | F401 | UnusedImport | `...` imported but unused | 🛠 |
@@ -255,12 +326,12 @@ The 🛠 emoji indicates that a rule is automatically fixable by the `--fix` com
 | F621 | ExpressionsInStarAssignment | Too many expressions in star-unpacking assignment |  |
 | F622 | TwoStarredExpressions | Two starred expressions in assignment |  |
 | F631 | AssertTuple | Assert test is a non-empty tuple, which is always `True` |  |
-| F632 | IsLiteral | Use `==` and `!=` to compare constant literals |  |
+| F632 | IsLiteral | Use `==` and `!=` to compare constant literals | 🛠 |
 | F633 | InvalidPrintSyntax | Use of `>>` is invalid with `print` function |  |
 | F634 | IfTuple | If test is a tuple, which is always `True` |  |
 | F701 | BreakOutsideLoop | `break` outside loop |  |
 | F702 | ContinueOutsideLoop | `continue` not properly in loop |  |
-| F704 | YieldOutsideFunction | `yield` or `yield from` statement outside of a function/method |  |
+| F704 | YieldOutsideFunction | `yield` or `yield from` statement outside of a function |  |
 | F706 | ReturnOutsideFunction | `return` statement outside of a function/method |  |
 | F707 | DefaultExceptNotLast | An `except:` block as not the last exception handler |  |
 | F722 | ForwardAnnotationSyntaxError | Syntax error in forward annotation: `...` |  |
@@ -269,9 +340,11 @@ The 🛠 emoji indicates that a rule is automatically fixable by the `--fix` com
 | F823 | UndefinedLocal | Local variable `...` referenced before assignment |  |
 | F831 | DuplicateArgumentName | Duplicate argument name in function definition |  |
 | F841 | UnusedVariable | Local variable `...` is assigned to but never used |  |
-| F901 | RaiseNotImplemented | `raise NotImplemented` should be `raise NotImplementedError` |  |
+| F901 | RaiseNotImplemented | `raise NotImplemented` should be `raise NotImplementedError` | 🛠 |
 
-### pycodestyle (error)
+### pycodestyle
+
+For more, see [pycodestyle](https://pypi.org/project/pycodestyle/2.9.1/) on PyPI.
 
 | Code | Name | Message | Fix |
 | ---- | ---- | ------- | --- |
@@ -289,16 +362,13 @@ The 🛠 emoji indicates that a rule is automatically fixable by the `--fix` com
 | E743 | AmbiguousFunctionName | Ambiguous function name: `...` |  |
 | E902 | IOError | IOError: `...` |  |
 | E999 | SyntaxError | SyntaxError: `...` |  |
-
-### pycodestyle (warning)
-
-| Code | Name | Message | Fix |
-| ---- | ---- | ------- | --- |
 | W292 | NoNewLineAtEndOfFile | No newline at end of file |  |
 | W605 | InvalidEscapeSequence | Invalid escape sequence: '\c' |  |
 
 ### pydocstyle
 
+For more, see [pydocstyle](https://pypi.org/project/pydocstyle/6.1.1/) on PyPI.
+
 | Code | Name | Message | Fix |
 | ---- | ---- | ------- | --- |
 | D100 | PublicModule | Missing docstring in public module |  |
@@ -329,7 +399,7 @@ The 🛠 emoji indicates that a rule is automatically fixable by the `--fix` com
 | D400 | EndsInPeriod | First line should end with a period |  |
 | D402 | NoSignature | First line should not be the function's signature |  |
 | D403 | FirstLineCapitalized | First word of the first line should be properly capitalized |  |
-| D404 | NoThisPrefix | First word of the docstring should not be `This` |  |
+| D404 | NoThisPrefix | First word of the docstring should not be 'This' |  |
 | D405 | CapitalizeSectionName | Section name should be properly capitalized ("returns") | 🛠 |
 | D406 | NewLineAfterSectionName | Section name should end with a newline ("Returns") | 🛠 |
 | D407 | DashedUnderlineAfterSection | Missing dashed underline after section ("Returns") | 🛠 |
@@ -343,11 +413,13 @@ The 🛠 emoji indicates that a rule is automatically fixable by the `--fix` com
 | D415 | EndsInPunctuation | First line should end with a period, question mark, or exclamation point |  |
 | D416 | SectionNameEndsInColon | Section name should end with a colon ("Returns") | 🛠 |
 | D417 | DocumentAllArguments | Missing argument descriptions in the docstring: `x`, `y` |  |
-| D418 | SkipDocstring | Function decorated with @overload shouldn't contain a docstring |  |
+| D418 | SkipDocstring | Function decorated with `@overload` shouldn't contain a docstring |  |
 | D419 | NonEmpty | Docstring is empty |  |
 
 ### pyupgrade
 
+For more, see [pyupgrade](https://pypi.org/project/pyupgrade/3.2.0/) on PyPI.
+
 | Code | Name | Message | Fix |
 | ---- | ---- | ------- | --- |
 | U001 | UselessMetaclassType | `__metaclass__ = type` is implied | 🛠 |
@@ -358,9 +430,13 @@ The 🛠 emoji indicates that a rule is automatically fixable by the `--fix` com
 | U006 | UsePEP585Annotation | Use `list` instead of `List` for type annotations | 🛠 |
 | U007 | UsePEP604Annotation | Use `X \| Y` for type annotations | 🛠 |
 | U008 | SuperCallWithParameters | Use `super()` instead of `super(__class__, self)` | 🛠 |
+| U009 | PEP3120UnnecessaryCodingComment | utf-8 encoding declaration is unnecessary | 🛠 |
+| U010 | UnnecessaryFutureImport | Unnessary __future__ import `...` for target Python version |  |
 
 ### pep8-naming
 
+For more, see [pep8-naming](https://pypi.org/project/pep8-naming/0.13.2/) on PyPI.
+
 | Code | Name | Message | Fix |
 | ---- | ---- | ------- | --- |
 | N801 | InvalidClassName | Class name `...` should use CapWords convention  |  |
@@ -381,39 +457,53 @@ The 🛠 emoji indicates that a rule is automatically fixable by the `--fix` com
 
 ### flake8-comprehensions
 
+For more, see [flake8-comprehensions](https://pypi.org/project/flake8-comprehensions/3.10.1/) on PyPI.
+
 | Code | Name | Message | Fix |
 | ---- | ---- | ------- | --- |
-| C400 | UnnecessaryGeneratorList | Unnecessary generator (rewrite as a `list` comprehension) |  |
-| C401 | UnnecessaryGeneratorSet | Unnecessary generator (rewrite as a `set` comprehension) |  |
-| C402 | UnnecessaryGeneratorDict | Unnecessary generator (rewrite as a `dict` comprehension) |  |
-| C403 | UnnecessaryListComprehensionSet | Unnecessary `list` comprehension (rewrite as a `set` comprehension) |  |
-| C404 | UnnecessaryListComprehensionDict | Unnecessary `list` comprehension (rewrite as a `dict` comprehension) |  |
-| C405 | UnnecessaryLiteralSet | Unnecessary `(list\|tuple)` literal (rewrite as a `set` literal) |  |
-| C406 | UnnecessaryLiteralDict | Unnecessary `(list\|tuple)` literal (rewrite as a `dict` literal) |  |
-| C408 | UnnecessaryCollectionCall | Unnecessary `(dict\|list\|tuple)` call (rewrite as a literal) |  |
-| C409 | UnnecessaryLiteralWithinTupleCall | Unnecessary `(list\|tuple)` literal passed to `tuple()` (remove the outer call to `tuple()`) |  |
-| C410 | UnnecessaryLiteralWithinListCall | Unnecessary `(list\|tuple)` literal passed to `list()` (rewrite as a `list` literal) |  |
-| C411 | UnnecessaryListCall | Unnecessary `list` call (remove the outer call to `list()`) |  |
+| C400 | UnnecessaryGeneratorList | Unnecessary generator (rewrite as a `list` comprehension) | 🛠 |
+| C401 | UnnecessaryGeneratorSet | Unnecessary generator (rewrite as a `set` comprehension) | 🛠 |
+| C402 | UnnecessaryGeneratorDict | Unnecessary generator (rewrite as a `dict` comprehension) | 🛠 |
+| C403 | UnnecessaryListComprehensionSet | Unnecessary `list` comprehension (rewrite as a `set` comprehension) | 🛠 |
+| C404 | UnnecessaryListComprehensionDict | Unnecessary `list` comprehension (rewrite as a `dict` comprehension) | 🛠 |
+| C405 | UnnecessaryLiteralSet | Unnecessary `(list\|tuple)` literal (rewrite as a `set` literal) | 🛠 |
+| C406 | UnnecessaryLiteralDict | Unnecessary `(list\|tuple)` literal (rewrite as a `dict` literal) | 🛠 |
+| C408 | UnnecessaryCollectionCall | Unnecessary `(dict\|list\|tuple)` call (rewrite as a literal) | 🛠 |
+| C409 | UnnecessaryLiteralWithinTupleCall | Unnecessary `(list\|tuple)` literal passed to `tuple()` (remove the outer call to `tuple()`) | 🛠 |
+| C410 | UnnecessaryLiteralWithinListCall | Unnecessary `(list\|tuple)` literal passed to `list()` (rewrite as a `list` literal) | 🛠 |
+| C411 | UnnecessaryListCall | Unnecessary `list` call (remove the outer call to `list()`) | 🛠 |
 | C413 | UnnecessaryCallAroundSorted | Unnecessary `(list\|reversed)` call around `sorted()` |  |
 | C414 | UnnecessaryDoubleCastOrProcess | Unnecessary `(list\|reversed\|set\|sorted\|tuple)` call within `(list\|set\|sorted\|tuple)()` |  |
 | C415 | UnnecessarySubscriptReversal | Unnecessary subscript reversal of iterable within `(reversed\|set\|sorted)()` |  |
-| C416 | UnnecessaryComprehension |  Unnecessary `(list\|set)` comprehension (rewrite using `(list\|set)()`) |  |
+| C416 | UnnecessaryComprehension | Unnecessary `(list\|set)` comprehension (rewrite using `(list\|set)()`) | 🛠 |
 | C417 | UnnecessaryMap | Unnecessary `map` usage (rewrite using a `(list\|set\|dict)` comprehension) |  |
 
 ### flake8-bugbear
 
+For more, see [flake8-bugbear](https://pypi.org/project/flake8-bugbear/22.10.27/) on PyPI.
+
 | Code | Name | Message | Fix |
 | ---- | ---- | ------- | --- |
 | B002 | UnaryPrefixIncrement | Python does not support the unary prefix increment. |  |
+| B003 | AssignmentToOsEnviron | Assigning to `os.environ` doesn't clear the environment. |  |
+| B004 | UnreliableCallableCheck |  Using `hasattr(x, '__call__')` to test if x is callable is unreliable. Use `callable(x)` for consistent results. |  |
+| B005 | StripWithMultiCharacters | Using `.strip()` with multi-character strings is misleading the reader. |  |
+| B006 | MutableArgumentDefault | Do not use mutable data structures for argument defaults. |  |
 | B007 | UnusedLoopControlVariable | Loop control variable `i` not used within the loop body. | 🛠 |
+| B008 | FunctionCallArgumentDefault | Do not perform function calls in argument defaults. |  |
 | B011 | DoNotAssertFalse | Do not `assert False` (`python -O` removes these calls), raise `AssertionError()` | 🛠 |
 | B013 | RedundantTupleInExceptionHandler | A length-one tuple literal is redundant. Write `except ValueError:` instead of `except (ValueError,):`. |  |
 | B014 | DuplicateHandlerException | Exception handler with duplicate exception: `ValueError` | 🛠 |
+| B015 | UselessComparison | Pointless comparison. This comparison does nothing but waste CPU instructions. Either prepend `assert` or remove it. |  |
+| B016 | CannotRaiseLiteral | Cannot raise a literal. Did you intend to return it or raise an Exception? |  |
 | B017 | NoAssertRaisesException | `assertRaises(Exception):` should be considered evil. |  |
+| B018 | UselessExpression | Found useless expression. Either assign it to a variable or remove it. |  |
 | B025 | DuplicateTryBlockException | try-except block with duplicate exception `Exception` |  |
 
 ### flake8-builtins
 
+For more, see [flake8-builtins](https://pypi.org/project/flake8-builtins/2.0.1/) on PyPI.
+
 | Code | Name | Message | Fix |
 | ---- | ---- | ------- | --- |
 | A001 | BuiltinVariableShadowing | Variable `...` is shadowing a python builtin |  |
@@ -422,6 +512,8 @@ The 🛠 emoji indicates that a rule is automatically fixable by the `--fix` com
 
 ### flake8-print
 
+For more, see [flake8-print](https://pypi.org/project/flake8-print/5.0.0/) on PyPI.
+
 | Code | Name | Message | Fix |
 | ---- | ---- | ------- | --- |
 | T201 | PrintFound | `print` found | 🛠 |
@@ -429,6 +521,8 @@ The 🛠 emoji indicates that a rule is automatically fixable by the `--fix` com
 
 ### flake8-quotes
 
+For more, see [flake8-quotes](https://pypi.org/project/flake8-quotes/3.3.1/) on PyPI.
+
 | Code | Name | Message | Fix |
 | ---- | ---- | ------- | --- |
 | Q000 | BadQuotesInlineString | Single quotes found but double quotes preferred |  |
@@ -436,12 +530,40 @@ The 🛠 emoji indicates that a rule is automatically fixable by the `--fix` com
 | Q002 | BadQuotesDocstring | Single quote docstring found but double quotes preferred |  |
 | Q003 | AvoidQuoteEscape | Change outer quotes to avoid escaping inner quotes |  |
 
+### flake8-annotations
+
+For more, see [flake8-annotations](https://pypi.org/project/flake8-annotations/2.9.1/) on PyPI.
+
+| Code | Name | Message | Fix |
+| ---- | ---- | ------- | --- |
+| ANN001 | MissingTypeFunctionArgument | Missing type annotation for function argument `...` |  |
+| ANN002 | MissingTypeArgs | Missing type annotation for `*...` |  |
+| ANN003 | MissingTypeKwargs | Missing type annotation for `**...` |  |
+| ANN101 | MissingTypeSelf | Missing type annotation for `...` in method |  |
+| ANN102 | MissingTypeCls | Missing type annotation for `...` in classmethod |  |
+| ANN201 | MissingReturnTypePublicFunction | Missing return type annotation for public function `...` |  |
+| ANN202 | MissingReturnTypePrivateFunction | Missing return type annotation for private function `...` |  |
+| ANN204 | MissingReturnTypeMagicMethod | Missing return type annotation for magic method `...` |  |
+| ANN205 | MissingReturnTypeStaticMethod | Missing return type annotation for staticmethod `...` |  |
+| ANN206 | MissingReturnTypeClassMethod | Missing return type annotation for classmethod `...` |  |
+| ANN401 | DynamicallyTypedExpression | Dynamically typed expressions (typing.Any) are disallowed in `...` |  |
+
+### Ruff-specific rules
+
+| Code | Name | Message | Fix |
+| ---- | ---- | ------- | --- |
+| RUF001 | AmbiguousUnicodeCharacterString | String contains ambiguous unicode character '𝐁' (did you mean 'B'?) | 🛠 |
+| RUF002 | AmbiguousUnicodeCharacterDocstring | Docstring contains ambiguous unicode character '𝐁' (did you mean 'B'?) | 🛠 |
+| RUF003 | AmbiguousUnicodeCharacterComment | Comment contains ambiguous unicode character '𝐁' (did you mean 'B'?) |  |
+
 ### Meta rules
 
 | Code | Name | Message | Fix |
 | ---- | ---- | ------- | --- |
 | M001 | UnusedNOQA | Unused `noqa` directive | 🛠 |
 
+<!-- End auto-generated sections. -->
+
 ## Editor Integrations
 
 ### PyCharm
@@ -492,6 +614,9 @@ stylistic lint rules that are obviated by autoformatting.
 
 ### How does Ruff compare to Flake8?
 
+(Coming from Flake8? Try [`flake8-to-ruff`](https://pypi.org/project/flake8-to-ruff/) to
+automatically convert your existing configuration.)
+
 Ruff can be used as a (near) drop-in replacement for Flake8 when used (1) without or with a small
 number of plugins, (2) alongside Black, and (3) on Python 3 code.
 
@@ -509,9 +634,10 @@ including:
 - [`flake8-super`](https://pypi.org/project/flake8-super/)
 - [`flake8-print`](https://pypi.org/project/flake8-print/)
 - [`flake8-quotes`](https://pypi.org/project/flake8-quotes/)
+- [`flake8-annotations`](https://pypi.org/project/flake8-annotations/)
 - [`flake8-comprehensions`](https://pypi.org/project/flake8-comprehensions/)
-- [`flake8-bugbear`](https://pypi.org/project/flake8-bugbear/) (10/32)
-- [`pyupgrade`](https://pypi.org/project/pyupgrade/) (8/34)
+- [`flake8-bugbear`](https://pypi.org/project/flake8-bugbear/) (17/32)
+- [`pyupgrade`](https://pypi.org/project/pyupgrade/) (12/34)
 - [`autoflake`](https://pypi.org/project/autoflake/) (1/7)
 
 Beyond rule-set parity, Ruff suffers from the following limitations vis-à-vis Flake8:
@@ -531,11 +657,12 @@ Today, Ruff can be used to replace Flake8 when used with any of the following pl
 - [`flake8-super`](https://pypi.org/project/flake8-super/)
 - [`flake8-print`](https://pypi.org/project/flake8-print/)
 - [`flake8-quotes`](https://pypi.org/project/flake8-quotes/)
+- [`flake8-annotations`](https://pypi.org/project/flake8-annotations/)
 - [`flake8-comprehensions`](https://pypi.org/project/flake8-comprehensions/)
-- [`flake8-bugbear`](https://pypi.org/project/flake8-bugbear/) (9/32)
+- [`flake8-bugbear`](https://pypi.org/project/flake8-bugbear/) (17/32)
 
 Ruff also implements the functionality that you get from [`yesqa`](https://github.com/asottile/yesqa),
-and a subset of the rules implemented in [`pyupgrade`](https://pypi.org/project/pyupgrade/) (8/34).
+and a subset of the rules implemented in [`pyupgrade`](https://pypi.org/project/pyupgrade/) (12/34).
 
 If you're looking to use Ruff, but rely on an unsupported Flake8 plugin, free to file an Issue.
 
@@ -627,16 +754,21 @@ extend-ignore = [
 
 ## Development
 
-Ruff is written in Rust (1.63.0). You'll need to install the [Rust toolchain](https://www.rust-lang.org/tools/install)
+Ruff is written in Rust (1.65.0). You'll need to install the [Rust toolchain](https://www.rust-lang.org/tools/install)
 for development.
 
 Assuming you have `cargo` installed, you can run:
 
 ```shell
 cargo run resources/test/fixtures
-cargo fmt
-cargo clippy
-cargo test
+```
+
+For development, we use [nightly Rust](https://rust-lang.github.io/rustup/concepts/channels.html#working-with-nightly-rust):
+
+```shell
+cargo +nightly fmt
+cargo +nightly clippy
+cargo +nightly test
 ```
 
 ## Releases

benches/source_code_locator.rs

@@ -0,0 +1,18 @@
+use std::path::Path;
+
+use criterion::{black_box, criterion_group, criterion_main, Criterion};
+use ropey::Rope;
+use ruff::fs;
+
+fn criterion_benchmark(c: &mut Criterion) {
+    let contents = fs::read_file(Path::new("resources/test/fixtures/D.py")).unwrap();
+    c.bench_function("rope", |b| {
+        b.iter(|| {
+            let rope = Rope::from_str(black_box(&contents));
+            rope.line_to_char(black_box(4));
+        })
+    });
+}
+
+criterion_group!(benches, criterion_benchmark);
+criterion_main!(benches);

examples/generate_rules_table.rs

@@ -1,29 +0,0 @@
-//! Generate a Markdown-compatible table of supported lint rules.
-
-use strum::IntoEnumIterator;
-
-use ruff::checks::{CheckCategory, CheckCode};
-
-fn main() {
-    for check_category in CheckCategory::iter() {
-        println!("### {}", check_category.title());
-        println!();
-
-        println!("| Code | Name | Message | Fix |");
-        println!("| ---- | ---- | ------- | --- |");
-        for check_code in CheckCode::iter() {
-            if check_code.category() == check_category {
-                let check_kind = check_code.kind();
-                let fix_token = if check_kind.fixable() { "🛠" } else { "" };
-                println!(
-                    "| {} | {} | {} | {} |",
-                    check_kind.code().as_ref(),
-                    check_kind.as_ref(),
-                    check_kind.summary().replace("|", r"\|"),
-                    fix_token
-                );
-            }
-        }
-        println!();
-    }
-}

flake8_to_ruff/Cargo.toml

@@ -0,0 +1,22 @@
+[package]
+name = "flake8-to-ruff"
+version = "0.0.108-dev.0"
+edition = "2021"
+
+[lib]
+name = "flake8_to_ruff"
+
+[dependencies]
+anyhow = { version = "1.0.60" }
+clap = { version = "4.0.1", features = ["derive"] }
+configparser = { version = "3.0.2" }
+once_cell = { version = "1.13.1" }
+regex = { version = "1.6.0" }
+ruff = { path = "..", default-features = false }
+serde = { version = "1.0.143", features = ["derive"] }
+serde_json = { version = "1.0.83" }
+toml = { version = "0.5.9" }
+
+[dev-dependencies]
+
+[features]

flake8_to_ruff/README.md

@@ -0,0 +1,98 @@
+# flake8-to-ruff
+
+Convert existing Flake8 configuration files (`setup.cfg`, `tox.ini`, or `.flake8`) for use with
+[Ruff](https://github.com/charliermarsh/ruff).
+
+Generates a Ruff-compatible `pyproject.toml` section.
+
+## Installation and Usage
+
+### Installation
+
+Available as [`flake8-to-ruff`](https://pypi.org/project/flake8-to-ruff/) on PyPI:
+
+```shell
+pip install flake8-to-ruff
+```
+
+### Usage
+
+To run `flake8-to-ruff`:
+
+```shell
+flake8-to-ruff path/to/setup.cfg
+flake8-to-ruff path/to/tox.ini
+flake8-to-ruff path/to/.flake8
+```
+
+`flake8-to-ruff` will print the relevant `pyproject.toml` sections to standard output, like so:
+
+```toml
+[tool.ruff]
+exclude = [
+    '.svn',
+    'CVS',
+    '.bzr',
+    '.hg',
+    '.git',
+    '__pycache__',
+    '.tox',
+    '.idea',
+    '.mypy_cache',
+    '.venv',
+    'node_modules',
+    '_state_machine.py',
+    'test_fstring.py',
+    'bad_coding2.py',
+    'badsyntax_*.py',
+]
+select = [
+    'A',
+    'E',
+    'F',
+    'Q',
+]
+ignore = []
+
+[tool.ruff.flake8-quotes]
+inline-quotes = 'single'
+
+[tool.ruff.pep8-naming]
+ignore-names = [
+    'foo',
+    'bar',
+]
+```
+
+### Plugins
+
+`flake8-to-ruff` will attempt to infer any activated plugins based on the settings provided in your
+configuration file.
+
+For example, if your `.flake8` file includes a `docstring-convention` property, `flake8-to-ruff`
+will enable the appropriate [`flake8-docstrings`](https://pypi.org/project/flake8-docstrings/)
+checks.
+
+Alternatively, you can manually specify plugins on the command-line:
+
+```shell
+flake8-to-ruff path/to/.flake8 --plugin flake8-builtins --plugin flake8-quotes
+```
+
+## Limitations
+
+1. Ruff only supports a subset of the Flake configuration options. `flake8-to-ruff` will warn on and
+   ignore unsupported options in the `.flake8` file (or equivalent). (Similarly, Ruff has a few
+   configuration options that don't exist in Flake8.)
+2. Ruff will omit any error codes that are unimplemented or unsupported by Ruff, including error
+   codes from unsupported plugins. (See the [Ruff README](https://github.com/charliermarsh/ruff#user-content-how-does-ruff-compare-to-flake8)
+   for the complete list of supported plugins.)
+
+## License
+
+MIT
+
+## Contributing
+
+Contributions are welcome and hugely appreciated. To get started, check out the
+[contributing guidelines](https://github.com/charliermarsh/ruff/blob/main/CONTRIBUTING.md).

flake8_to_ruff/examples/poetry.ini

@@ -0,0 +1,36 @@
+[flake8]
+min_python_version = 3.7.0
+max-line-length = 88
+ban-relative-imports = true
+# flake8-use-fstring: https://github.com/MichaelKim0407/flake8-use-fstring#--percent-greedy-and---format-greedy
+format-greedy = 1
+inline-quotes = double
+enable-extensions = TC, TC1
+type-checking-strict = true
+eradicate-whitelist-extend = ^-.*;
+extend-ignore =
+    # E203: Whitespace before ':' (pycqa/pycodestyle#373)
+    E203,
+    # SIM106: Handle error-cases first
+    SIM106,
+    # ANN101: Missing type annotation for self in method
+    ANN101,
+    # ANN102: Missing type annotation for cls in classmethod
+    ANN102,
+    # PIE781: assign-and-return
+    PIE781,
+    # PIE798 no-unnecessary-class: Consider using a module for namespacing instead
+    PIE798,
+per-file-ignores =
+    # TC002: Move third-party import '...' into a type-checking block
+    __init__.py:TC002,
+    # ANN201: Missing return type annotation for public function
+    tests/test_*:ANN201
+    tests/**/test_*:ANN201
+extend-exclude =
+    # Frozen and not subject to change in this repo:
+    get-poetry.py,
+    install-poetry.py,
+    # External to the project's coding standards:
+    tests/fixtures/*,
+    tests/**/fixtures/*,

flake8_to_ruff/examples/python-discord.ini

@@ -0,0 +1,19 @@
+[flake8]
+max-line-length=120
+docstring-convention=all
+import-order-style=pycharm
+application_import_names=bot,tests
+exclude=.cache,.venv,.git,constants.py
+extend-ignore=
+    B311,W503,E226,S311,T000,E731
+    # Missing Docstrings
+    D100,D104,D105,D107,
+    # Docstring Whitespace
+    D203,D212,D214,D215,
+    # Docstring Quotes
+    D301,D302,
+    # Docstring Content
+    D400,D401,D402,D404,D405,D406,D407,D408,D409,D410,D411,D412,D413,D414,D416,D417
+    # Type Annotations
+    ANN002,ANN003,ANN101,ANN102,ANN204,ANN206,ANN401
+per-file-ignores=tests/*:D,ANN

flake8_to_ruff/examples/requests.ini

@@ -0,0 +1,6 @@
+[flake8]
+ignore = E203, E501, W503
+per-file-ignores =
+    requests/__init__.py:E402, F401
+    requests/compat.py:E402, F401
+    tests/compat.py:F401

flake8_to_ruff/pyproject.toml

@@ -0,0 +1,33 @@
+[project]
+name = "flake8-to-ruff"
+keywords = ["automation", "flake8", "pycodestyle", "pyflakes", "pylint", "clippy"]
+classifiers = [
+    "Development Status :: 3 - Alpha",
+    "Environment :: Console",
+    "Intended Audience :: Developers",
+    "License :: OSI Approved :: MIT License",
+    "Operating System :: OS Independent",
+    "Programming Language :: Python",
+    "Programming Language :: Python :: 3.7",
+    "Programming Language :: Python :: 3.8",
+    "Programming Language :: Python :: 3.9",
+    "Programming Language :: Python :: 3.10",
+    "Programming Language :: Python :: 3 :: Only",
+    "Topic :: Software Development :: Libraries :: Python Modules",
+    "Topic :: Software Development :: Quality Assurance",
+]
+author = "Charlie Marsh"
+author_email = "charlie.r.marsh@gmail.com"
+description = "Convert existing Flake8 configuration to Ruff."
+requires-python = ">=3.7"
+
+[project.urls]
+repository = "https://github.com/charliermarsh/ruff#subdirectory=crates/flake8_to_ruff"
+
+[build-system]
+requires = ["maturin>=0.13,<0.14"]
+build-backend = "maturin"
+
+[tool.maturin]
+bindings = "bin"
+strip = true

flake8_to_ruff/src/converter.rs

@@ -0,0 +1,468 @@
+use std::collections::{BTreeSet, HashMap};
+
+use anyhow::Result;
+use ruff::checks_gen::CheckCodePrefix;
+use ruff::flake8_quotes::settings::Quote;
+use ruff::settings::options::Options;
+use ruff::settings::pyproject::Pyproject;
+use ruff::{flake8_annotations, flake8_quotes, pep8_naming};
+
+use crate::plugin::Plugin;
+use crate::{parser, plugin};
+
+pub fn convert(
+    flake8: &HashMap<String, Option<String>>,
+    plugins: Option<Vec<Plugin>>,
+) -> Result<Pyproject> {
+    // Extract all referenced check code prefixes, to power plugin inference.
+    let mut referenced_codes: BTreeSet<CheckCodePrefix> = Default::default();
+    for (key, value) in flake8 {
+        if let Some(value) = value {
+            match key.as_str() {
+                "select" | "ignore" | "extend-select" | "extend_select" | "extend-ignore"
+                | "extend_ignore" => {
+                    referenced_codes.extend(parser::parse_prefix_codes(value.as_ref()));
+                }
+                "per-file-ignores" | "per_file_ignores" => {
+                    if let Ok(per_file_ignores) =
+                        parser::parse_files_to_codes_mapping(value.as_ref())
+                    {
+                        for (_, codes) in parser::collect_per_file_ignores(per_file_ignores) {
+                            referenced_codes.extend(codes);
+                        }
+                    }
+                }
+                _ => {}
+            }
+        }
+    }
+
+    // Check if the user has specified a `select`. If not, we'll add our own
+    // default `select`, and populate it based on user plugins.
+    let mut select = flake8
+        .get("select")
+        .and_then(|value| {
+            value
+                .as_ref()
+                .map(|value| BTreeSet::from_iter(parser::parse_prefix_codes(value)))
+        })
+        .unwrap_or_else(|| {
+            plugin::resolve_select(
+                flake8,
+                &plugins.unwrap_or_else(|| {
+                    plugin::infer_plugins_from_options(flake8)
+                        .into_iter()
+                        .chain(plugin::infer_plugins_from_codes(&referenced_codes))
+                        .collect()
+                }),
+            )
+        });
+    let mut ignore = flake8
+        .get("ignore")
+        .and_then(|value| {
+            value
+                .as_ref()
+                .map(|value| BTreeSet::from_iter(parser::parse_prefix_codes(value)))
+        })
+        .unwrap_or_default();
+
+    // Parse each supported option.
+    let mut options: Options = Default::default();
+    let mut flake8_annotations: flake8_annotations::settings::Options = Default::default();
+    let mut flake8_quotes: flake8_quotes::settings::Options = Default::default();
+    let mut pep8_naming: pep8_naming::settings::Options = Default::default();
+    for (key, value) in flake8 {
+        if let Some(value) = value {
+            match key.as_str() {
+                // flake8
+                "max-line-length" | "max_line_length" => match value.clone().parse::<usize>() {
+                    Ok(line_length) => options.line_length = Some(line_length),
+                    Err(e) => eprintln!("Unable to parse '{key}' property: {e}"),
+                },
+                "select" => {
+                    // No-op (handled above).
+                    select.extend(parser::parse_prefix_codes(value.as_ref()));
+                }
+                "ignore" => {
+                    // No-op (handled above).
+                }
+                "extend-select" | "extend_select" => {
+                    // Unlike Flake8, use a single explicit `select`.
+                    select.extend(parser::parse_prefix_codes(value.as_ref()));
+                }
+                "extend-ignore" | "extend_ignore" => {
+                    // Unlike Flake8, use a single explicit `ignore`.
+                    ignore.extend(parser::parse_prefix_codes(value.as_ref()));
+                }
+                "exclude" => {
+                    options.exclude = Some(parser::parse_strings(value.as_ref()));
+                }
+                "extend-exclude" | "extend_exclude" => {
+                    options.extend_exclude = Some(parser::parse_strings(value.as_ref()));
+                }
+                "per-file-ignores" | "per_file_ignores" => {
+                    match parser::parse_files_to_codes_mapping(value.as_ref()) {
+                        Ok(per_file_ignores) => {
+                            options.per_file_ignores =
+                                Some(parser::collect_per_file_ignores(per_file_ignores))
+                        }
+                        Err(e) => eprintln!("Unable to parse '{key}' property: {e}"),
+                    }
+                }
+                // flake8-annotations
+                "suppress-none-returning" | "suppress_none_returning" => {
+                    match parser::parse_bool(value.as_ref()) {
+                        Ok(bool) => flake8_annotations.suppress_none_returning = Some(bool),
+                        Err(e) => eprintln!("Unable to parse '{key}' property: {e}"),
+                    }
+                }
+                "suppress-dummy-args" | "suppress_dummy_args" => {
+                    match parser::parse_bool(value.as_ref()) {
+                        Ok(bool) => flake8_annotations.suppress_dummy_args = Some(bool),
+                        Err(e) => eprintln!("Unable to parse '{key}' property: {e}"),
+                    }
+                }
+                "mypy-init-return" | "mypy_init_return" => {
+                    match parser::parse_bool(value.as_ref()) {
+                        Ok(bool) => flake8_annotations.mypy_init_return = Some(bool),
+                        Err(e) => eprintln!("Unable to parse '{key}' property: {e}"),
+                    }
+                }
+                "allow-star-arg-any" | "allow_star_arg_any" => {
+                    match parser::parse_bool(value.as_ref()) {
+                        Ok(bool) => flake8_annotations.allow_star_arg_any = Some(bool),
+                        Err(e) => eprintln!("Unable to parse '{key}' property: {e}"),
+                    }
+                }
+                // flake8-quotes
+                "quotes" | "inline-quotes" | "inline_quotes" => match value.trim() {
+                    "'" | "single" => flake8_quotes.inline_quotes = Some(Quote::Single),
+                    "\"" | "double" => flake8_quotes.inline_quotes = Some(Quote::Single),
+                    _ => eprintln!("Unexpected '{key}' value: {value}"),
+                },
+                "multiline-quotes" | "multiline_quotes" => match value.trim() {
+                    "'" | "single" => flake8_quotes.multiline_quotes = Some(Quote::Single),
+                    "\"" | "double" => flake8_quotes.multiline_quotes = Some(Quote::Single),
+                    _ => eprintln!("Unexpected '{key}' value: {value}"),
+                },
+                "docstring-quotes" | "docstring_quotes" => match value.trim() {
+                    "'" | "single" => flake8_quotes.docstring_quotes = Some(Quote::Single),
+                    "\"" | "double" => flake8_quotes.docstring_quotes = Some(Quote::Single),
+                    _ => eprintln!("Unexpected '{key}' value: {value}"),
+                },
+                "avoid-escape" | "avoid_escape" => match parser::parse_bool(value.as_ref()) {
+                    Ok(bool) => flake8_quotes.avoid_escape = Some(bool),
+                    Err(e) => eprintln!("Unable to parse '{key}' property: {e}"),
+                },
+                // pep8-naming
+                "ignore-names" | "ignore_names" => {
+                    pep8_naming.ignore_names = Some(parser::parse_strings(value.as_ref()));
+                }
+                "classmethod-decorators" | "classmethod_decorators" => {
+                    pep8_naming.classmethod_decorators =
+                        Some(parser::parse_strings(value.as_ref()));
+                }
+                "staticmethod-decorators" | "staticmethod_decorators" => {
+                    pep8_naming.staticmethod_decorators =
+                        Some(parser::parse_strings(value.as_ref()));
+                }
+                // flake8-docstrings
+                "docstring-convention" => {
+                    // No-op (handled above).
+                }
+                // Unknown
+                _ => eprintln!("Skipping unsupported property: {key}"),
+            }
+        }
+    }
+
+    // Deduplicate and sort.
+    options.select = Some(Vec::from_iter(select));
+    options.ignore = Some(Vec::from_iter(ignore));
+    if flake8_quotes != Default::default() {
+        options.flake8_quotes = Some(flake8_quotes);
+    }
+    if pep8_naming != Default::default() {
+        options.pep8_naming = Some(pep8_naming);
+    }
+
+    // Create the pyproject.toml.
+    Ok(Pyproject::new(options))
+}
+
+#[cfg(test)]
+mod tests {
+    use std::collections::HashMap;
+
+    use anyhow::Result;
+    use ruff::checks_gen::CheckCodePrefix;
+    use ruff::flake8_quotes;
+    use ruff::settings::options::Options;
+    use ruff::settings::pyproject::Pyproject;
+
+    use crate::converter::convert;
+    use crate::plugin::Plugin;
+
+    #[test]
+    fn it_converts_empty() -> Result<()> {
+        let actual = convert(&HashMap::from([]), None)?;
+        let expected = Pyproject::new(Options {
+            line_length: None,
+            fix: None,
+            exclude: None,
+            extend_exclude: None,
+            select: Some(vec![
+                CheckCodePrefix::E,
+                CheckCodePrefix::F,
+                CheckCodePrefix::W,
+            ]),
+            extend_select: None,
+            ignore: Some(vec![]),
+            extend_ignore: None,
+            per_file_ignores: None,
+            dummy_variable_rgx: None,
+            target_version: None,
+            flake8_annotations: None,
+            flake8_quotes: None,
+            pep8_naming: None,
+        });
+        assert_eq!(actual, expected);
+
+        Ok(())
+    }
+
+    #[test]
+    fn it_converts_dashes() -> Result<()> {
+        let actual = convert(
+            &HashMap::from([("max-line-length".to_string(), Some("100".to_string()))]),
+            Some(vec![]),
+        )?;
+        let expected = Pyproject::new(Options {
+            line_length: Some(100),
+            fix: None,
+            exclude: None,
+            extend_exclude: None,
+            select: Some(vec![
+                CheckCodePrefix::E,
+                CheckCodePrefix::F,
+                CheckCodePrefix::W,
+            ]),
+            extend_select: None,
+            ignore: Some(vec![]),
+            extend_ignore: None,
+            per_file_ignores: None,
+            dummy_variable_rgx: None,
+            target_version: None,
+            flake8_annotations: None,
+            flake8_quotes: None,
+            pep8_naming: None,
+        });
+        assert_eq!(actual, expected);
+
+        Ok(())
+    }
+
+    #[test]
+    fn it_converts_underscores() -> Result<()> {
+        let actual = convert(
+            &HashMap::from([("max_line_length".to_string(), Some("100".to_string()))]),
+            Some(vec![]),
+        )?;
+        let expected = Pyproject::new(Options {
+            line_length: Some(100),
+            fix: None,
+            exclude: None,
+            extend_exclude: None,
+            select: Some(vec![
+                CheckCodePrefix::E,
+                CheckCodePrefix::F,
+                CheckCodePrefix::W,
+            ]),
+            extend_select: None,
+            ignore: Some(vec![]),
+            extend_ignore: None,
+            per_file_ignores: None,
+            dummy_variable_rgx: None,
+            target_version: None,
+            flake8_annotations: None,
+            flake8_quotes: None,
+            pep8_naming: None,
+        });
+        assert_eq!(actual, expected);
+
+        Ok(())
+    }
+
+    #[test]
+    fn it_ignores_parse_errors() -> Result<()> {
+        let actual = convert(
+            &HashMap::from([("max_line_length".to_string(), Some("abc".to_string()))]),
+            Some(vec![]),
+        )?;
+        let expected = Pyproject::new(Options {
+            line_length: None,
+            fix: None,
+            exclude: None,
+            extend_exclude: None,
+            select: Some(vec![
+                CheckCodePrefix::E,
+                CheckCodePrefix::F,
+                CheckCodePrefix::W,
+            ]),
+            extend_select: None,
+            ignore: Some(vec![]),
+            extend_ignore: None,
+            per_file_ignores: None,
+            dummy_variable_rgx: None,
+            target_version: None,
+            flake8_annotations: None,
+            flake8_quotes: None,
+            pep8_naming: None,
+        });
+        assert_eq!(actual, expected);
+
+        Ok(())
+    }
+
+    #[test]
+    fn it_converts_plugin_options() -> Result<()> {
+        let actual = convert(
+            &HashMap::from([("inline-quotes".to_string(), Some("single".to_string()))]),
+            Some(vec![]),
+        )?;
+        let expected = Pyproject::new(Options {
+            line_length: None,
+            fix: None,
+            exclude: None,
+            extend_exclude: None,
+            select: Some(vec![
+                CheckCodePrefix::E,
+                CheckCodePrefix::F,
+                CheckCodePrefix::W,
+            ]),
+            extend_select: None,
+            ignore: Some(vec![]),
+            extend_ignore: None,
+            per_file_ignores: None,
+            dummy_variable_rgx: None,
+            target_version: None,
+            flake8_annotations: None,
+            flake8_quotes: Some(flake8_quotes::settings::Options {
+                inline_quotes: Some(flake8_quotes::settings::Quote::Single),
+                multiline_quotes: None,
+                docstring_quotes: None,
+                avoid_escape: None,
+            }),
+            pep8_naming: None,
+        });
+        assert_eq!(actual, expected);
+
+        Ok(())
+    }
+
+    #[test]
+    fn it_converts_docstring_conventions() -> Result<()> {
+        let actual = convert(
+            &HashMap::from([(
+                "docstring-convention".to_string(),
+                Some("numpy".to_string()),
+            )]),
+            Some(vec![Plugin::Flake8Docstrings]),
+        )?;
+        let expected = Pyproject::new(Options {
+            line_length: None,
+            fix: None,
+            exclude: None,
+            extend_exclude: None,
+            select: Some(vec![
+                CheckCodePrefix::D100,
+                CheckCodePrefix::D101,
+                CheckCodePrefix::D102,
+                CheckCodePrefix::D103,
+                CheckCodePrefix::D104,
+                CheckCodePrefix::D105,
+                CheckCodePrefix::D106,
+                CheckCodePrefix::D200,
+                CheckCodePrefix::D201,
+                CheckCodePrefix::D202,
+                CheckCodePrefix::D204,
+                CheckCodePrefix::D205,
+                CheckCodePrefix::D206,
+                CheckCodePrefix::D207,
+                CheckCodePrefix::D208,
+                CheckCodePrefix::D209,
+                CheckCodePrefix::D210,
+                CheckCodePrefix::D211,
+                CheckCodePrefix::D214,
+                CheckCodePrefix::D215,
+                CheckCodePrefix::D300,
+                CheckCodePrefix::D400,
+                CheckCodePrefix::D403,
+                CheckCodePrefix::D404,
+                CheckCodePrefix::D405,
+                CheckCodePrefix::D406,
+                CheckCodePrefix::D407,
+                CheckCodePrefix::D408,
+                CheckCodePrefix::D409,
+                CheckCodePrefix::D410,
+                CheckCodePrefix::D411,
+                CheckCodePrefix::D412,
+                CheckCodePrefix::D414,
+                CheckCodePrefix::D418,
+                CheckCodePrefix::D419,
+                CheckCodePrefix::E,
+                CheckCodePrefix::F,
+                CheckCodePrefix::W,
+            ]),
+            extend_select: None,
+            ignore: Some(vec![]),
+            extend_ignore: None,
+            per_file_ignores: None,
+            dummy_variable_rgx: None,
+            target_version: None,
+            flake8_annotations: None,
+            flake8_quotes: None,
+            pep8_naming: None,
+        });
+        assert_eq!(actual, expected);
+
+        Ok(())
+    }
+
+    #[test]
+    fn it_infers_plugins_if_omitted() -> Result<()> {
+        let actual = convert(
+            &HashMap::from([("inline-quotes".to_string(), Some("single".to_string()))]),
+            None,
+        )?;
+        let expected = Pyproject::new(Options {
+            line_length: None,
+            fix: None,
+            exclude: None,
+            extend_exclude: None,
+            select: Some(vec![
+                CheckCodePrefix::E,
+                CheckCodePrefix::F,
+                CheckCodePrefix::Q,
+                CheckCodePrefix::W,
+            ]),
+            extend_select: None,
+            ignore: Some(vec![]),
+            extend_ignore: None,
+            per_file_ignores: None,
+            dummy_variable_rgx: None,
+            target_version: None,
+            flake8_annotations: None,
+            flake8_quotes: Some(flake8_quotes::settings::Options {
+                inline_quotes: Some(flake8_quotes::settings::Quote::Single),
+                multiline_quotes: None,
+                docstring_quotes: None,
+                avoid_escape: None,
+            }),
+            pep8_naming: None,
+        });
+        assert_eq!(actual, expected);
+
+        Ok(())
+    }
+}

flake8_to_ruff/src/lib.rs

@@ -0,0 +1,5 @@
+#![allow(clippy::collapsible_if, clippy::collapsible_else_if)]
+
+pub mod converter;
+mod parser;
+pub mod plugin;

flake8_to_ruff/src/main.rs

@@ -0,0 +1,44 @@
+//! Utility to generate Ruff's pyproject.toml section from a Flake8 INI file.
+
+use std::path::PathBuf;
+
+use anyhow::Result;
+use clap::Parser;
+use configparser::ini::Ini;
+use flake8_to_ruff::converter;
+use flake8_to_ruff::plugin::Plugin;
+
+#[derive(Parser)]
+#[command(
+    about = "Convert existing Flake8 configuration to Ruff.",
+    long_about = None
+)]
+struct Cli {
+    /// Path to the Flake8 configuration file (e.g., 'setup.cfg', 'tox.ini', or
+    /// '.flake8').
+    #[arg(required = true)]
+    file: PathBuf,
+    /// List of plugins to enable.
+    #[arg(long, value_delimiter = ',')]
+    plugin: Option<Vec<Plugin>>,
+}
+
+fn main() -> Result<()> {
+    let cli = Cli::parse();
+
+    // Read the INI file.
+    let mut ini = Ini::new_cs();
+    ini.set_multiline(true);
+    let config = ini.load(cli.file).map_err(|msg| anyhow::anyhow!(msg))?;
+
+    // Extract the Flake8 section.
+    let flake8 = config
+        .get("flake8")
+        .expect("Unable to find flake8 section in INI file.");
+
+    // Create the pyproject.toml.
+    let pyproject = converter::convert(flake8, cli.plugin)?;
+    println!("{}", toml::to_string_pretty(&pyproject)?);
+
+    Ok(())
+}

flake8_to_ruff/src/parser.rs

@@ -0,0 +1,382 @@
+use std::collections::BTreeMap;
+use std::str::FromStr;
+
+use anyhow::Result;
+use once_cell::sync::Lazy;
+use regex::Regex;
+use ruff::checks_gen::CheckCodePrefix;
+use ruff::settings::types::PatternPrefixPair;
+
+static COMMA_SEPARATED_LIST_RE: Lazy<Regex> = Lazy::new(|| Regex::new(r"[,\s]").unwrap());
+
+/// Parse a comma-separated list of `CheckCodePrefix` values (e.g.,
+/// "F401,E501").
+pub fn parse_prefix_codes(value: &str) -> Vec<CheckCodePrefix> {
+    let mut codes: Vec<CheckCodePrefix> = vec![];
+    for code in COMMA_SEPARATED_LIST_RE.split(value) {
+        let code = code.trim();
+        if code.is_empty() {
+            continue;
+        }
+        if let Ok(code) = CheckCodePrefix::from_str(code) {
+            codes.push(code);
+        } else {
+            eprintln!("Unsupported prefix code: {code}");
+        }
+    }
+    codes
+}
+
+/// Parse a comma-separated list of strings (e.g., "__init__.py,__main__.py").
+pub fn parse_strings(value: &str) -> Vec<String> {
+    COMMA_SEPARATED_LIST_RE
+        .split(value)
+        .map(|part| part.trim())
+        .filter(|part| !part.is_empty())
+        .map(String::from)
+        .collect()
+}
+
+/// Parse a boolean.
+pub fn parse_bool(value: &str) -> Result<bool> {
+    match value.trim() {
+        "true" => Ok(true),
+        "false" => Ok(false),
+        _ => Err(anyhow::anyhow!("Unexpected boolean value: {value}")),
+    }
+}
+
+#[derive(Debug)]
+struct Token {
+    token_name: TokenType,
+    src: String,
+}
+
+#[derive(Debug)]
+enum TokenType {
+    Code,
+    File,
+    Colon,
+    Comma,
+    Ws,
+    Eof,
+}
+
+struct State {
+    seen_sep: bool,
+    seen_colon: bool,
+    filenames: Vec<String>,
+    codes: Vec<String>,
+}
+
+impl State {
+    fn new() -> Self {
+        Self {
+            seen_sep: true,
+            seen_colon: false,
+            filenames: vec![],
+            codes: vec![],
+        }
+    }
+
+    /// Generate the list of `StrCheckCodePair` pairs for the current state.
+    fn parse(&self) -> Vec<PatternPrefixPair> {
+        let mut codes: Vec<PatternPrefixPair> = vec![];
+        for code in &self.codes {
+            match CheckCodePrefix::from_str(code) {
+                Ok(code) => {
+                    for filename in &self.filenames {
+                        codes.push(PatternPrefixPair {
+                            pattern: filename.clone(),
+                            prefix: code.clone(),
+                        });
+                    }
+                }
+                Err(_) => eprintln!("Skipping unrecognized prefix: {}", code),
+            }
+        }
+        codes
+    }
+}
+
+/// Tokenize the raw 'files-to-codes' mapping.
+fn tokenize_files_to_codes_mapping(value: &str) -> Vec<Token> {
+    let mut tokens = vec![];
+    let mut i = 0;
+    while i < value.len() {
+        for (token_re, token_name) in [
+            (
+                Regex::new(r"([A-Z]+[0-9]*)(?:$|\s|,)").unwrap(),
+                TokenType::Code,
+            ),
+            (Regex::new(r"([^\s:,]+)").unwrap(), TokenType::File),
+            (Regex::new(r"(\s*:\s*)").unwrap(), TokenType::Colon),
+            (Regex::new(r"(\s*,\s*)").unwrap(), TokenType::Comma),
+            (Regex::new(r"(\s+)").unwrap(), TokenType::Ws),
+        ] {
+            if let Some(cap) = token_re.captures(&value[i..]) {
+                let mat = cap.get(1).unwrap();
+                if mat.start() == 0 {
+                    tokens.push(Token {
+                        token_name,
+                        src: mat.as_str().to_string().trim().to_string(),
+                    });
+                    i += mat.end();
+                    break;
+                }
+            }
+        }
+    }
+    tokens.push(Token {
+        token_name: TokenType::Eof,
+        src: "".to_string(),
+    });
+    tokens
+}
+
+/// Parse a 'files-to-codes' mapping, mimicking Flake8's internal logic.
+///
+/// See: https://github.com/PyCQA/flake8/blob/7dfe99616fc2f07c0017df2ba5fa884158f3ea8a/src/flake8/utils.py#L45
+pub fn parse_files_to_codes_mapping(value: &str) -> Result<Vec<PatternPrefixPair>> {
+    if value.trim().is_empty() {
+        return Ok(vec![]);
+    }
+    let mut codes: Vec<PatternPrefixPair> = vec![];
+    let mut state = State::new();
+    for token in tokenize_files_to_codes_mapping(value) {
+        if matches!(token.token_name, TokenType::Comma | TokenType::Ws) {
+            state.seen_sep = true;
+        } else if !state.seen_colon {
+            if matches!(token.token_name, TokenType::Colon) {
+                state.seen_colon = true;
+                state.seen_sep = true;
+            } else if state.seen_sep && matches!(token.token_name, TokenType::File) {
+                state.filenames.push(token.src);
+                state.seen_sep = false;
+            } else {
+                return Err(anyhow::anyhow!("Unexpected token: {:?}", token.token_name));
+            }
+        } else {
+            if matches!(token.token_name, TokenType::Eof) {
+                codes.extend(state.parse());
+                state = State::new();
+            } else if state.seen_sep && matches!(token.token_name, TokenType::Code) {
+                state.codes.push(token.src);
+                state.seen_sep = false;
+            } else if state.seen_sep && matches!(token.token_name, TokenType::File) {
+                codes.extend(state.parse());
+                state = State::new();
+                state.filenames.push(token.src);
+                state.seen_sep = false;
+            } else {
+                return Err(anyhow::anyhow!("Unexpected token: {:?}", token.token_name));
+            }
+        }
+    }
+    Ok(codes)
+}
+
+/// Collect a list of `PatternPrefixPair` structs as a `BTreeMap`.
+pub fn collect_per_file_ignores(
+    pairs: Vec<PatternPrefixPair>,
+) -> BTreeMap<String, Vec<CheckCodePrefix>> {
+    let mut per_file_ignores: BTreeMap<String, Vec<CheckCodePrefix>> = BTreeMap::new();
+    for pair in pairs {
+        per_file_ignores
+            .entry(pair.pattern)
+            .or_insert_with(Vec::new)
+            .push(pair.prefix);
+    }
+    per_file_ignores
+}
+
+#[cfg(test)]
+mod tests {
+    use anyhow::Result;
+    use ruff::checks_gen::CheckCodePrefix;
+    use ruff::settings::types::PatternPrefixPair;
+
+    use crate::parser::{parse_files_to_codes_mapping, parse_prefix_codes, parse_strings};
+
+    #[test]
+    fn it_parses_prefix_codes() {
+        let actual = parse_prefix_codes("");
+        let expected: Vec<CheckCodePrefix> = vec![];
+        assert_eq!(actual, expected);
+
+        let actual = parse_prefix_codes(" ");
+        let expected: Vec<CheckCodePrefix> = vec![];
+        assert_eq!(actual, expected);
+
+        let actual = parse_prefix_codes("F401");
+        let expected = vec![CheckCodePrefix::F401];
+        assert_eq!(actual, expected);
+
+        let actual = parse_prefix_codes("F401,");
+        let expected = vec![CheckCodePrefix::F401];
+        assert_eq!(actual, expected);
+
+        let actual = parse_prefix_codes("F401,E501");
+        let expected = vec![CheckCodePrefix::F401, CheckCodePrefix::E501];
+        assert_eq!(actual, expected);
+
+        let actual = parse_prefix_codes("F401, E501");
+        let expected = vec![CheckCodePrefix::F401, CheckCodePrefix::E501];
+        assert_eq!(actual, expected);
+    }
+
+    #[test]
+    fn it_parses_strings() {
+        let actual = parse_strings("");
+        let expected: Vec<String> = vec![];
+        assert_eq!(actual, expected);
+
+        let actual = parse_strings(" ");
+        let expected: Vec<String> = vec![];
+        assert_eq!(actual, expected);
+
+        let actual = parse_strings("__init__.py");
+        let expected = vec!["__init__.py".to_string()];
+        assert_eq!(actual, expected);
+
+        let actual = parse_strings("__init__.py,");
+        let expected = vec!["__init__.py".to_string()];
+        assert_eq!(actual, expected);
+
+        let actual = parse_strings("__init__.py,__main__.py");
+        let expected = vec!["__init__.py".to_string(), "__main__.py".to_string()];
+        assert_eq!(actual, expected);
+
+        let actual = parse_strings("__init__.py, __main__.py");
+        let expected = vec!["__init__.py".to_string(), "__main__.py".to_string()];
+        assert_eq!(actual, expected);
+    }
+
+    #[test]
+    fn it_parse_files_to_codes_mapping() -> Result<()> {
+        let actual = parse_files_to_codes_mapping("")?;
+        let expected: Vec<PatternPrefixPair> = vec![];
+        assert_eq!(actual, expected);
+
+        let actual = parse_files_to_codes_mapping(" ")?;
+        let expected: Vec<PatternPrefixPair> = vec![];
+        assert_eq!(actual, expected);
+
+        // Ex) locust
+        let actual = parse_files_to_codes_mapping(
+            "per-file-ignores =
+    locust/test/*: F841
+    examples/*: F841
+    *.pyi: E302,E704"
+                .strip_prefix("per-file-ignores =")
+                .unwrap(),
+        )?;
+        let expected: Vec<PatternPrefixPair> = vec![
+            PatternPrefixPair {
+                pattern: "locust/test/*".to_string(),
+                prefix: CheckCodePrefix::F841,
+            },
+            PatternPrefixPair {
+                pattern: "examples/*".to_string(),
+                prefix: CheckCodePrefix::F841,
+            },
+        ];
+        assert_eq!(actual, expected);
+
+        // Ex) celery
+        let actual = parse_files_to_codes_mapping(
+            "per-file-ignores =
+   t/*,setup.py,examples/*,docs/*,extra/*:
+       D,"
+            .strip_prefix("per-file-ignores =")
+            .unwrap(),
+        )?;
+        let expected: Vec<PatternPrefixPair> = vec![
+            PatternPrefixPair {
+                pattern: "t/*".to_string(),
+                prefix: CheckCodePrefix::D,
+            },
+            PatternPrefixPair {
+                pattern: "setup.py".to_string(),
+                prefix: CheckCodePrefix::D,
+            },
+            PatternPrefixPair {
+                pattern: "examples/*".to_string(),
+                prefix: CheckCodePrefix::D,
+            },
+            PatternPrefixPair {
+                pattern: "docs/*".to_string(),
+                prefix: CheckCodePrefix::D,
+            },
+            PatternPrefixPair {
+                pattern: "extra/*".to_string(),
+                prefix: CheckCodePrefix::D,
+            },
+        ];
+        assert_eq!(actual, expected);
+
+        // Ex) scrapy
+        let actual = parse_files_to_codes_mapping(
+            "per-file-ignores =
+    scrapy/__init__.py:E402
+    scrapy/core/downloader/handlers/http.py:F401
+    scrapy/http/__init__.py:F401
+    scrapy/linkextractors/__init__.py:E402,F401
+    scrapy/selector/__init__.py:F401
+    scrapy/spiders/__init__.py:E402,F401
+    scrapy/utils/url.py:F403,F405
+    tests/test_loader.py:E741"
+                .strip_prefix("per-file-ignores =")
+                .unwrap(),
+        )?;
+        let expected: Vec<PatternPrefixPair> = vec![
+            PatternPrefixPair {
+                pattern: "scrapy/__init__.py".to_string(),
+                prefix: CheckCodePrefix::E402,
+            },
+            PatternPrefixPair {
+                pattern: "scrapy/core/downloader/handlers/http.py".to_string(),
+                prefix: CheckCodePrefix::F401,
+            },
+            PatternPrefixPair {
+                pattern: "scrapy/http/__init__.py".to_string(),
+                prefix: CheckCodePrefix::F401,
+            },
+            PatternPrefixPair {
+                pattern: "scrapy/linkextractors/__init__.py".to_string(),
+                prefix: CheckCodePrefix::E402,
+            },
+            PatternPrefixPair {
+                pattern: "scrapy/linkextractors/__init__.py".to_string(),
+                prefix: CheckCodePrefix::F401,
+            },
+            PatternPrefixPair {
+                pattern: "scrapy/selector/__init__.py".to_string(),
+                prefix: CheckCodePrefix::F401,
+            },
+            PatternPrefixPair {
+                pattern: "scrapy/spiders/__init__.py".to_string(),
+                prefix: CheckCodePrefix::E402,
+            },
+            PatternPrefixPair {
+                pattern: "scrapy/spiders/__init__.py".to_string(),
+                prefix: CheckCodePrefix::F401,
+            },
+            PatternPrefixPair {
+                pattern: "scrapy/utils/url.py".to_string(),
+                prefix: CheckCodePrefix::F403,
+            },
+            PatternPrefixPair {
+                pattern: "scrapy/utils/url.py".to_string(),
+                prefix: CheckCodePrefix::F405,
+            },
+            PatternPrefixPair {
+                pattern: "tests/test_loader.py".to_string(),
+                prefix: CheckCodePrefix::E741,
+            },
+        ];
+        assert_eq!(actual, expected);
+
+        Ok(())
+    }
+}

flake8_to_ruff/src/plugin.rs

@@ -0,0 +1,396 @@
+use std::collections::{BTreeSet, HashMap};
+use std::str::FromStr;
+
+use anyhow::anyhow;
+use ruff::checks_gen::CheckCodePrefix;
+
+#[derive(Debug, Clone, Ord, PartialOrd, Eq, PartialEq)]
+pub enum Plugin {
+    Flake8Bugbear,
+    Flake8Builtins,
+    Flake8Comprehensions,
+    Flake8Docstrings,
+    Flake8Print,
+    Flake8Quotes,
+    Flake8Annotations,
+    PEP8Naming,
+    Pyupgrade,
+}
+
+impl FromStr for Plugin {
+    type Err = anyhow::Error;
+
+    fn from_str(string: &str) -> Result<Self, Self::Err> {
+        match string {
+            "flake8-bugbear" => Ok(Plugin::Flake8Bugbear),
+            "flake8-builtins" => Ok(Plugin::Flake8Builtins),
+            "flake8-comprehensions" => Ok(Plugin::Flake8Comprehensions),
+            "flake8-docstrings" => Ok(Plugin::Flake8Docstrings),
+            "flake8-print" => Ok(Plugin::Flake8Print),
+            "flake8-quotes" => Ok(Plugin::Flake8Quotes),
+            "flake8-annotations" => Ok(Plugin::Flake8Annotations),
+            "pep8-naming" => Ok(Plugin::PEP8Naming),
+            "pyupgrade" => Ok(Plugin::Pyupgrade),
+            _ => Err(anyhow!("Unknown plugin: {}", string)),
+        }
+    }
+}
+
+impl Plugin {
+    pub fn default(&self) -> CheckCodePrefix {
+        match self {
+            Plugin::Flake8Bugbear => CheckCodePrefix::B,
+            Plugin::Flake8Builtins => CheckCodePrefix::A,
+            Plugin::Flake8Comprehensions => CheckCodePrefix::C,
+            Plugin::Flake8Docstrings => CheckCodePrefix::D,
+            Plugin::Flake8Print => CheckCodePrefix::T,
+            Plugin::Flake8Quotes => CheckCodePrefix::Q,
+            Plugin::Flake8Annotations => CheckCodePrefix::ANN,
+            Plugin::PEP8Naming => CheckCodePrefix::N,
+            Plugin::Pyupgrade => CheckCodePrefix::U,
+        }
+    }
+
+    pub fn select(&self, flake8: &HashMap<String, Option<String>>) -> Vec<CheckCodePrefix> {
+        match self {
+            Plugin::Flake8Bugbear => vec![CheckCodePrefix::B],
+            Plugin::Flake8Builtins => vec![CheckCodePrefix::A],
+            Plugin::Flake8Comprehensions => vec![CheckCodePrefix::C],
+            Plugin::Flake8Docstrings => {
+                // Use the user-provided docstring.
+                for key in ["docstring-convention", "docstring_convention"] {
+                    if let Some(Some(value)) = flake8.get(key) {
+                        match DocstringConvention::from_str(value) {
+                            Ok(convention) => return convention.select(),
+                            Err(e) => {
+                                eprintln!("Unexpected '{key}' value: {value} ({e}");
+                                return vec![];
+                            }
+                        }
+                    }
+                }
+                // Default to PEP8.
+                DocstringConvention::PEP8.select()
+            }
+            Plugin::Flake8Print => vec![CheckCodePrefix::T],
+            Plugin::Flake8Quotes => vec![CheckCodePrefix::Q],
+            Plugin::Flake8Annotations => vec![CheckCodePrefix::ANN],
+            Plugin::PEP8Naming => vec![CheckCodePrefix::N],
+            Plugin::Pyupgrade => vec![CheckCodePrefix::U],
+        }
+    }
+}
+
+pub enum DocstringConvention {
+    All,
+    PEP8,
+    NumPy,
+    Google,
+}
+
+impl FromStr for DocstringConvention {
+    type Err = anyhow::Error;
+
+    fn from_str(string: &str) -> Result<Self, Self::Err> {
+        match string {
+            "all" => Ok(DocstringConvention::All),
+            "pep8" => Ok(DocstringConvention::PEP8),
+            "numpy" => Ok(DocstringConvention::NumPy),
+            "google" => Ok(DocstringConvention::Google),
+            _ => Err(anyhow!("Unknown docstring convention: {}", string)),
+        }
+    }
+}
+
+impl DocstringConvention {
+    fn select(&self) -> Vec<CheckCodePrefix> {
+        match self {
+            DocstringConvention::All => vec![CheckCodePrefix::D],
+            DocstringConvention::PEP8 => vec![
+                // All errors except D203, D212, D213, D214, D215, D404, D405, D406, D407, D408,
+                // D409, D410, D411, D413, D415, D416 and D417.
+                CheckCodePrefix::D100,
+                CheckCodePrefix::D101,
+                CheckCodePrefix::D102,
+                CheckCodePrefix::D103,
+                CheckCodePrefix::D104,
+                CheckCodePrefix::D105,
+                CheckCodePrefix::D106,
+                CheckCodePrefix::D107,
+                CheckCodePrefix::D200,
+                CheckCodePrefix::D201,
+                CheckCodePrefix::D202,
+                // CheckCodePrefix::D203,
+                CheckCodePrefix::D204,
+                CheckCodePrefix::D205,
+                CheckCodePrefix::D206,
+                CheckCodePrefix::D207,
+                CheckCodePrefix::D208,
+                CheckCodePrefix::D209,
+                CheckCodePrefix::D210,
+                CheckCodePrefix::D211,
+                // CheckCodePrefix::D212,
+                // CheckCodePrefix::D213,
+                // CheckCodePrefix::D214,
+                // CheckCodePrefix::D215,
+                CheckCodePrefix::D300,
+                CheckCodePrefix::D400,
+                CheckCodePrefix::D402,
+                CheckCodePrefix::D403,
+                // CheckCodePrefix::D404,
+                // CheckCodePrefix::D405,
+                // CheckCodePrefix::D406,
+                // CheckCodePrefix::D407,
+                // CheckCodePrefix::D408,
+                // CheckCodePrefix::D409,
+                // CheckCodePrefix::D410,
+                // CheckCodePrefix::D411,
+                CheckCodePrefix::D412,
+                // CheckCodePrefix::D413,
+                CheckCodePrefix::D414,
+                // CheckCodePrefix::D415,
+                // CheckCodePrefix::D416,
+                // CheckCodePrefix::D417,
+                CheckCodePrefix::D418,
+                CheckCodePrefix::D419,
+            ],
+            DocstringConvention::NumPy => vec![
+                // All errors except D107, D203, D212, D213, D402, D413, D415, D416, and D417.
+                CheckCodePrefix::D100,
+                CheckCodePrefix::D101,
+                CheckCodePrefix::D102,
+                CheckCodePrefix::D103,
+                CheckCodePrefix::D104,
+                CheckCodePrefix::D105,
+                CheckCodePrefix::D106,
+                // CheckCodePrefix::D107,
+                CheckCodePrefix::D200,
+                CheckCodePrefix::D201,
+                CheckCodePrefix::D202,
+                // CheckCodePrefix::D203,
+                CheckCodePrefix::D204,
+                CheckCodePrefix::D205,
+                CheckCodePrefix::D206,
+                CheckCodePrefix::D207,
+                CheckCodePrefix::D208,
+                CheckCodePrefix::D209,
+                CheckCodePrefix::D210,
+                CheckCodePrefix::D211,
+                // CheckCodePrefix::D212,
+                // CheckCodePrefix::D213,
+                CheckCodePrefix::D214,
+                CheckCodePrefix::D215,
+                CheckCodePrefix::D300,
+                CheckCodePrefix::D400,
+                // CheckCodePrefix::D402,
+                CheckCodePrefix::D403,
+                CheckCodePrefix::D404,
+                CheckCodePrefix::D405,
+                CheckCodePrefix::D406,
+                CheckCodePrefix::D407,
+                CheckCodePrefix::D408,
+                CheckCodePrefix::D409,
+                CheckCodePrefix::D410,
+                CheckCodePrefix::D411,
+                CheckCodePrefix::D412,
+                // CheckCodePrefix::D413,
+                CheckCodePrefix::D414,
+                // CheckCodePrefix::D415,
+                // CheckCodePrefix::D416,
+                // CheckCodePrefix::D417,
+                CheckCodePrefix::D418,
+                CheckCodePrefix::D419,
+            ],
+            DocstringConvention::Google => vec![
+                // All errors except D203, D204, D213, D215, D400, D401, D404, D406, D407, D408,
+                // D409 and D413.
+                CheckCodePrefix::D100,
+                CheckCodePrefix::D101,
+                CheckCodePrefix::D102,
+                CheckCodePrefix::D103,
+                CheckCodePrefix::D104,
+                CheckCodePrefix::D105,
+                CheckCodePrefix::D106,
+                CheckCodePrefix::D107,
+                CheckCodePrefix::D200,
+                CheckCodePrefix::D201,
+                CheckCodePrefix::D202,
+                // CheckCodePrefix::D203,
+                // CheckCodePrefix::D204,
+                CheckCodePrefix::D205,
+                CheckCodePrefix::D206,
+                CheckCodePrefix::D207,
+                CheckCodePrefix::D208,
+                CheckCodePrefix::D209,
+                CheckCodePrefix::D210,
+                CheckCodePrefix::D211,
+                CheckCodePrefix::D212,
+                // CheckCodePrefix::D213,
+                CheckCodePrefix::D214,
+                // CheckCodePrefix::D215,
+                CheckCodePrefix::D300,
+                // CheckCodePrefix::D400,
+                CheckCodePrefix::D402,
+                CheckCodePrefix::D403,
+                // CheckCodePrefix::D404,
+                CheckCodePrefix::D405,
+                // CheckCodePrefix::D406,
+                // CheckCodePrefix::D407,
+                // CheckCodePrefix::D408,
+                // CheckCodePrefix::D409,
+                CheckCodePrefix::D410,
+                CheckCodePrefix::D411,
+                CheckCodePrefix::D412,
+                // CheckCodePrefix::D413,
+                CheckCodePrefix::D414,
+                CheckCodePrefix::D415,
+                CheckCodePrefix::D416,
+                CheckCodePrefix::D417,
+                CheckCodePrefix::D418,
+                CheckCodePrefix::D419,
+            ],
+        }
+    }
+}
+
+/// Infer the enabled plugins based on user-provided options.
+///
+/// For example, if the user specified a `mypy-init-return` setting, we should
+/// infer that `flake8-annotations` is active.
+pub fn infer_plugins_from_options(flake8: &HashMap<String, Option<String>>) -> Vec<Plugin> {
+    let mut plugins = BTreeSet::new();
+    for key in flake8.keys() {
+        match key.as_str() {
+            // flake8-docstrings
+            "docstring-convention" | "docstring_convention" => {
+                plugins.insert(Plugin::Flake8Docstrings);
+            }
+            // flake8-builtins
+            "builtins-ignorelist" | "builtins_ignorelist" => {
+                plugins.insert(Plugin::Flake8Builtins);
+            }
+            // flake8-quotes
+            "quotes" | "inline-quotes" | "inline_quotes" => {
+                plugins.insert(Plugin::Flake8Quotes);
+            }
+            "multiline-quotes" | "multiline_quotes" => {
+                plugins.insert(Plugin::Flake8Quotes);
+            }
+            "docstring-quotes" | "docstring_quotes" => {
+                plugins.insert(Plugin::Flake8Quotes);
+            }
+            "avoid-escape" | "avoid_escape" => {
+                plugins.insert(Plugin::Flake8Quotes);
+            }
+            // flake8-annotations
+            "suppress-none-returning" | "suppress_none_returning" => {
+                plugins.insert(Plugin::Flake8Annotations);
+            }
+            "suppress-dummy-args" | "suppress_dummy_args" => {
+                plugins.insert(Plugin::Flake8Annotations);
+            }
+            "allow-untyped-defs" | "allow_untyped_defs" => {
+                plugins.insert(Plugin::Flake8Annotations);
+            }
+            "allow-untyped-nested" | "allow_untyped_nested" => {
+                plugins.insert(Plugin::Flake8Annotations);
+            }
+            "mypy-init-return" | "mypy_init_return" => {
+                plugins.insert(Plugin::Flake8Annotations);
+            }
+            "dispatch-decorators" | "dispatch_decorators" => {
+                plugins.insert(Plugin::Flake8Annotations);
+            }
+            "overload-decorators" | "overload_decorators" => {
+                plugins.insert(Plugin::Flake8Annotations);
+            }
+            "allow-star-arg-any" | "allow_star_arg_any" => {
+                plugins.insert(Plugin::Flake8Annotations);
+            }
+            // pep8-naming
+            "ignore-names" | "ignore_names" => {
+                plugins.insert(Plugin::PEP8Naming);
+            }
+            "classmethod-decorators" | "classmethod_decorators" => {
+                plugins.insert(Plugin::PEP8Naming);
+            }
+            "staticmethod-decorators" | "staticmethod_decorators" => {
+                plugins.insert(Plugin::PEP8Naming);
+            }
+            _ => {}
+        }
+    }
+    Vec::from_iter(plugins)
+}
+
+/// Infer the enabled plugins based on the referenced prefixes.
+///
+/// For example, if the user ignores `ANN101`, we should infer that
+/// `flake8-annotations` is active.
+pub fn infer_plugins_from_codes(codes: &BTreeSet<CheckCodePrefix>) -> Vec<Plugin> {
+    [
+        Plugin::Flake8Bugbear,
+        Plugin::Flake8Builtins,
+        Plugin::Flake8Comprehensions,
+        Plugin::Flake8Docstrings,
+        Plugin::Flake8Print,
+        Plugin::Flake8Quotes,
+        Plugin::Flake8Annotations,
+        Plugin::PEP8Naming,
+        Plugin::Pyupgrade,
+    ]
+    .into_iter()
+    .filter(|plugin| {
+        for prefix in codes {
+            if prefix
+                .codes()
+                .iter()
+                .any(|code| plugin.default().codes().contains(code))
+            {
+                return true;
+            }
+        }
+        false
+    })
+    .collect()
+}
+
+/// Resolve the set of enabled `CheckCodePrefix` values for the given plugins.
+pub fn resolve_select(
+    flake8: &HashMap<String, Option<String>>,
+    plugins: &[Plugin],
+) -> BTreeSet<CheckCodePrefix> {
+    // Include default Pyflakes and pycodestyle checks.
+    let mut select = BTreeSet::from([CheckCodePrefix::E, CheckCodePrefix::F, CheckCodePrefix::W]);
+
+    // Add prefix codes for every plugin.
+    for plugin in plugins {
+        select.extend(plugin.select(flake8));
+    }
+
+    select
+}
+
+#[cfg(test)]
+mod tests {
+    use std::collections::HashMap;
+
+    use crate::plugin::{infer_plugins_from_options, Plugin};
+
+    #[test]
+    fn it_infers_plugins() {
+        let actual = infer_plugins_from_options(&HashMap::from([(
+            "inline-quotes".to_string(),
+            Some("single".to_string()),
+        )]));
+        let expected = vec![Plugin::Flake8Quotes];
+        assert_eq!(actual, expected);
+
+        let actual = infer_plugins_from_options(&HashMap::from([(
+            "staticmethod-decorators".to_string(),
+            Some("[]".to_string()),
+        )]));
+        let expected = vec![Plugin::PEP8Naming];
+        assert_eq!(actual, expected);
+    }
+}

resources/test/fixtures/B003.py

@@ -0,0 +1,18 @@
+"""
+Should emit:
+B003 - on line 9
+"""
+
+import os
+from os import environ
+
+os.environ = {}
+environ = {}  # that's fine, assigning a new meaning to the module-level name
+
+
+class Object:
+    os = None
+
+
+o = Object()
+o.os.environ = {}

resources/test/fixtures/B004.py

@@ -0,0 +1,12 @@
+def this_is_a_bug():
+    o = object()
+    if hasattr(o, "__call__"):
+        print("Ooh, callable! Or is it?")
+    if getattr(o, "__call__", False):
+        print("Ooh, callable! Or is it?")
+
+
+def this_is_fine():
+    o = object()
+    if callable(o):
+        print("Ooh, this is actually callable.")

resources/test/fixtures/B005.py

@@ -0,0 +1,26 @@
+s = "qwe"
+s.strip(s)  # no warning
+s.strip("we")  # no warning
+s.strip(".facebook.com")  # warning
+s.strip("e")  # no warning
+s.strip("\n\t ")  # no warning
+s.strip(r"\n\t ")  # warning
+s.lstrip(s)  # no warning
+s.lstrip("we")  # no warning
+s.lstrip(".facebook.com")  # warning
+s.lstrip("e")  # no warning
+s.lstrip("\n\t ")  # no warning
+s.lstrip(r"\n\t ")  # warning
+s.rstrip(s)  # no warning
+s.rstrip("we")  # warning
+s.rstrip(".facebook.com")  # warning
+s.rstrip("e")  # no warning
+s.rstrip("\n\t ")  # no warning
+s.rstrip(r"\n\t ")  # warning
+
+from somewhere import other_type, strip
+
+strip("we")  # no warning
+other_type().lstrip()  # no warning
+other_type().rstrip(["a", "b", "c"])  # no warning
+other_type().strip("a", "b")  # no warning

resources/test/fixtures/B006_B008.py

@@ -0,0 +1,187 @@
+import collections
+import datetime as dt
+import logging
+import operator
+import random
+import re
+import time
+import types
+from operator import attrgetter, itemgetter, methodcaller
+from types import MappingProxyType
+
+
+# B006
+# Allow immutable literals/calls/comprehensions
+def this_is_okay(value=(1, 2, 3)):
+    ...
+
+
+async def and_this_also(value=tuple()):
+    pass
+
+
+def frozenset_also_okay(value=frozenset()):
+    pass
+
+
+def mappingproxytype_okay(
+    value=MappingProxyType({}), value2=types.MappingProxyType({})
+):
+    pass
+
+
+def re_compile_ok(value=re.compile("foo")):
+    pass
+
+
+def operators_ok(
+    v=operator.attrgetter("foo"),
+    v2=operator.itemgetter("foo"),
+    v3=operator.methodcaller("foo"),
+):
+    pass
+
+
+def operators_ok_unqualified(
+    v=attrgetter("foo"),
+    v2=itemgetter("foo"),
+    v3=methodcaller("foo"),
+):
+    pass
+
+
+def kwonlyargs_immutable(*, value=()):
+    ...
+
+
+# Flag mutable literals/comprehensions
+
+
+def this_is_wrong(value=[1, 2, 3]):
+    ...
+
+
+def this_is_also_wrong(value={}):
+    ...
+
+
+def and_this(value=set()):
+    ...
+
+
+def this_too(value=collections.OrderedDict()):
+    ...
+
+
+async def async_this_too(value=collections.defaultdict()):
+    ...
+
+
+def dont_forget_me(value=collections.deque()):
+    ...
+
+
+# N.B. we're also flagging the function call in the comprehension
+def list_comprehension_also_not_okay(default=[i**2 for i in range(3)]):
+    pass
+
+
+def dict_comprehension_also_not_okay(default={i: i**2 for i in range(3)}):
+    pass
+
+
+def set_comprehension_also_not_okay(default={i**2 for i in range(3)}):
+    pass
+
+
+def kwonlyargs_mutable(*, value=[]):
+    ...
+
+
+# Recommended approach for mutable defaults
+def do_this_instead(value=None):
+    if value is None:
+        value = set()
+
+
+# B008
+# Flag function calls as default args (including if they are part of a sub-expression)
+def in_fact_all_calls_are_wrong(value=time.time()):
+    ...
+
+
+def f(when=dt.datetime.now() + dt.timedelta(days=7)):
+    pass
+
+
+def can_even_catch_lambdas(a=(lambda x: x)()):
+    ...
+
+
+# Recommended approach for function calls as default args
+LOGGER = logging.getLogger(__name__)
+
+
+def do_this_instead_of_calls_in_defaults(logger=LOGGER):
+    # That makes it more obvious that this one value is reused.
+    ...
+
+
+# Handle inf/infinity/nan special case
+def float_inf_okay(value=float("inf")):
+    pass
+
+
+def float_infinity_okay(value=float("infinity")):
+    pass
+
+
+def float_plus_infinity_okay(value=float("+infinity")):
+    pass
+
+
+def float_minus_inf_okay(value=float("-inf")):
+    pass
+
+
+def float_nan_okay(value=float("nan")):
+    pass
+
+
+def float_minus_NaN_okay(value=float("-NaN")):
+    pass
+
+
+def float_infinity_literal(value=float("1e999")):
+    pass
+
+
+# But don't allow standard floats
+def float_int_is_wrong(value=float(3)):
+    pass
+
+
+def float_str_not_inf_or_nan_is_wrong(value=float("3.14")):
+    pass
+
+
+# B006 and B008
+# We should handle arbitrary nesting of these B008.
+def nested_combo(a=[float(3), dt.datetime.now()]):
+    pass
+
+
+# Don't flag nested B006 since we can't guarantee that
+# it isn't made mutable by the outer operation.
+def no_nested_b006(a=map(lambda s: s.upper(), ["a", "b", "c"])):
+    pass
+
+
+# B008-ception.
+def nested_b008(a=random.randint(0, dt.datetime.now().year)):
+    pass
+
+
+# Ignore lambda contents since they are evaluated at call time.
+def foo(f=lambda x: print(x)):
+    f(1)

resources/test/fixtures/B015.py

@@ -0,0 +1,27 @@
+assert 1 == 1
+
+1 == 1
+
+assert 1 in (1, 2)
+
+1 in (1, 2)
+
+
+if 1 == 2:
+    pass
+
+
+def test():
+    assert 1 in (1, 2)
+
+    1 in (1, 2)
+
+
+data = [x for x in [1, 2, 3] if x in (1, 2)]
+
+
+class TestClass:
+    1 == 1
+
+
+print(1 == 1)

resources/test/fixtures/B016.py

@@ -0,0 +1,11 @@
+"""
+Should emit:
+B016 - on lines 6, 7, and 8
+"""
+
+raise False
+raise 1
+raise "string"
+raise Exception(False)
+raise Exception(1)
+raise Exception("string")

resources/test/fixtures/B018.py

@@ -0,0 +1,59 @@
+class Foo1:
+    """abc"""
+
+
+class Foo2:
+    """abc"""
+
+    a = 2
+    "str"  # Str (no raise)
+    f"{int}"  # JoinedStr (no raise)
+    1j  # Number (complex)
+    1  # Number (int)
+    1.0  # Number (float)
+    b"foo"  # Binary
+    True  # NameConstant (True)
+    False  # NameConstant (False)
+    None  # NameConstant (None)
+    [1, 2]  # list
+    {1, 2}  # set
+    {"foo": "bar"}  # dict
+
+
+class Foo3:
+    123
+    a = 2
+    "str"
+    1
+
+
+def foo1():
+    """my docstring"""
+
+
+def foo2():
+    """my docstring"""
+    a = 2
+    "str"  # Str (no raise)
+    f"{int}"  # JoinedStr (no raise)
+    1j  # Number (complex)
+    1  # Number (int)
+    1.0  # Number (float)
+    b"foo"  # Binary
+    True  # NameConstant (True)
+    False  # NameConstant (False)
+    None  # NameConstant (None)
+    [1, 2]  # list
+    {1, 2}  # set
+    {"foo": "bar"}  # dict
+
+
+def foo3():
+    123
+    a = 2
+    "str"
+    3
+
+
+def foo4():
+    ...

resources/test/fixtures/C400.py

@@ -1 +1,4 @@
 x = list(x for x in range(3))
+x = list(
+    x for x in range(3)
+)

resources/test/fixtures/C401.py

@@ -1 +1,4 @@
 x = set(x for x in range(3))
+x = set(
+    x for x in range(3)
+)

resources/test/fixtures/C402.py

@@ -1 +1,5 @@
-d = dict((x, x) for x in range(3))
+dict((x, x) for x in range(3))
+dict(
+    (x, x) for x in range(3)
+)
+dict(((x, x) for x in range(3)), z=3)

resources/test/fixtures/C403.py

@@ -1 +1,4 @@
 s = set([x for x in range(3)])
+s = set(
+    [x for x in range(3)]
+)

resources/test/fixtures/C404.py

@@ -1 +1,2 @@
-d = dict([(i, i) for i in range(3)])
+dict([(i, i) for i in range(3)])
+dict([(i, i) for i in range(3)], z=4)

resources/test/fixtures/C409.py

@@ -1,3 +1,10 @@
-t1 = tuple([1, 2])
-t2 = tuple((1, 2))
-t3 = tuple([])
+t1 = tuple([])
+t2 = tuple([1, 2])
+t3 = tuple((1, 2))
+t4 = tuple([
+    1,
+    2
+])
+t5 = tuple(
+    (1, 2)
+)

resources/test/fixtures/E501.py

@@ -14,3 +14,38 @@ Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor i
 
 _ = "---------------------------------------------------------------------------AAAAAAA"
 _ = "---------------------------------------------------------------------------亜亜亜亜亜亜亜"
+
+
+def caller(string: str) -> None:
+    assert string is not None
+
+
+caller(
+    """
+    Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.
+    """,
+)
+
+
+caller(
+    """
+    Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.
+    """,  # noqa: E501
+)
+
+multiple_strings_per_line = {
+    # OK
+    "Lorem ipsum dolor": "sit amet",
+    # E501 Line too long
+    "Lorem ipsum dolor": "sit amet consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.",
+    # E501 Line too long
+    "Lorem ipsum dolor": """
+sit amet  consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.
+""",
+    # OK
+    "Lorem ipsum dolor": "sit amet consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.",  # noqa: E501
+    # OK
+    "Lorem ipsum dolor": """
+sit amet  consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.
+""",  # noqa: E501
+}

resources/test/fixtures/F632.py

@@ -3,3 +3,6 @@ if x is "abc":
 
 if 123 is not y:
     pass
+
+if "123" is x < 3:
+    pass

resources/test/fixtures/F821_1.py

@@ -0,0 +1,30 @@
+"""Test: typing module imports."""
+from foo import cast
+
+# OK
+x = cast("Model")
+
+from typing import cast
+
+
+# F821 Undefined name `Model`
+x = cast("Model", x)
+
+
+import typing
+
+
+# F821 Undefined name `Model`
+x = typing.cast("Model", x)
+
+
+from typing import Pattern
+
+# F821 Undefined name `Model`
+x = Pattern["Model"]
+
+
+from typing.re import Match
+
+# F821 Undefined name `Model`
+x = Match["Model"]

resources/test/fixtures/F821_2.py

@@ -0,0 +1,18 @@
+"""Test: typing_extensions module imports."""
+from foo import Literal
+
+# F821 Undefined name `Model`
+x: Literal["Model"]
+
+from typing_extensions import Literal
+
+
+# OK
+x: Literal["Model"]
+
+
+import typing_extensions
+
+
+# OK
+x: typing_extensions.Literal["Model"]

resources/test/fixtures/F821_3.py

@@ -0,0 +1,14 @@
+"""Test (edge case): accesses of object named `dict`."""
+
+# OK
+dict = {"parameters": {}}
+dict["parameters"]["userId"] = "userId"
+dict["parameters"]["itemId"] = "itemId"
+del dict["parameters"]["itemId"]
+
+# F821 Undefined name `key`
+# F821 Undefined name `value`
+x: dict["key", "value"]
+
+# OK
+x: dict[str, str]

resources/test/fixtures/N803.py

@@ -1,7 +1,7 @@
-def func(a, A):
-    return a, A
+def func(_, a, A):
+    return _, a, A
 
 
 class Class:
-    def method(self, a, A):
-        return a, A
+    def method(self, _, a, A):
+        return _, a, A

resources/test/fixtures/N804.py

@@ -1,19 +1,43 @@
+from abc import ABCMeta
+
+
 class Class:
-    @classmethod
-    def bad_class_method(this):
+    def bad_method(this):
+        pass
+
+    if False:
+
+        def extra_bad_method(this):
+            pass
+
+    def good_method(self):
         pass
 
     @classmethod
-    def good_class_method(cls):
-        pass
-
-    def method(self):
+    def class_method(cls):
         pass
 
     @staticmethod
     def static_method(x):
         return x
 
+    def __init__(self):
+        ...
+
+    def __new__(cls, *args, **kwargs):
+        ...
+
+    def __init_subclass__(self, default_name, **kwargs):
+        ...
+
+
+class MetaClass(ABCMeta):
+    def bad_method(self):
+        pass
+
+    def good_method(cls):
+        pass
+
 
 def func(x):
     return x

resources/test/fixtures/N805.py

@@ -1,11 +1,11 @@
-import random
+from abc import ABCMeta
 
 
 class Class:
     def bad_method(this):
         pass
 
-    if random.random(0, 2) == 0:
+    if False:
 
         def extra_bad_method(this):
             pass
@@ -21,6 +21,23 @@ class Class:
     def static_method(x):
         return x
 
+    def __init__(self):
+        ...
+
+    def __new__(cls, *args, **kwargs):
+        ...
+
+    def __init_subclass__(self, default_name, **kwargs):
+        ...
+
+
+class MetaClass(ABCMeta):
+    def bad_method(self):
+        pass
+
+    def good_method(cls):
+        pass
+
 
 def func(x):
     return x

resources/test/fixtures/N806.py

@@ -2,3 +2,4 @@ def f():
     lower = 0
     Camel = 0
     CONSTANT = 0
+    _ = 0

resources/test/fixtures/RUF001.py

@@ -0,0 +1,7 @@
+x = "𝐁ad string"
+
+
+def f():
+    """Here's a docstring with an unusual parenthesis: ）"""
+    # And here's a comment with an unusual punctuation mark: ᜵
+    ...

resources/test/fixtures/RUF002.py

@@ -0,0 +1,7 @@
+x = "𝐁ad string"
+
+
+def f():
+    """Here's a docstring with an unusual parenthesis: ）"""
+    # And here's a comment with an unusual punctuation mark: ᜵
+    ...

resources/test/fixtures/RUF003.py

@@ -0,0 +1,7 @@
+x = "𝐁ad string"
+
+
+def f():
+    """Here's a docstring with an unusual parenthesis: ）"""
+    # And here's a comment with an unusual punctuation mark: ᜵
+    ...

resources/test/fixtures/U009_0.py

@@ -0,0 +1,3 @@
+# coding=utf8
+
+print('Hello world')

resources/test/fixtures/U009_1.py

@@ -0,0 +1,4 @@
+#!/usr/bin/python
+# -*- coding: utf-8 -*-
+
+print('Hello world')

resources/test/fixtures/U009_2.py

@@ -0,0 +1,5 @@
+#!/usr/bin/python
+# A coding comment is only valid in the first two lines, so this one is not checked.
+# -*- coding: utf-8 -*-
+
+print('Hello world')

resources/test/fixtures/U009_3.py

@@ -0,0 +1,4 @@
+#!/usr/bin/python
+# -*- coding: something-else -*-
+
+print('Hello world')

resources/test/fixtures/U010.py

@@ -0,0 +1,5 @@
+from __future__ import annotations, nested_scopes, generators
+
+from __future__ import absolute_import, division
+
+from __future__ import generator_stop

resources/test/fixtures/W605_1.py

@@ -0,0 +1,35 @@
+#: W605:1:10
+regex = '\.png$'
+
+#: W605:2:1
+regex = '''
+\.png$
+'''
+
+#: W605:2:6
+f(
+    '\_'
+)
+
+#: W605:4:6
+"""
+multi-line
+literal
+with \_ somewhere
+in the middle
+"""
+
+#: Okay
+regex = r'\.png$'
+regex = '\\.png$'
+regex = r'''
+\.png$
+'''
+regex = r'''
+\\.png$
+'''
+s = '\\'
+regex = '\w'  # noqa
+regex = '''
+\w
+'''  # noqa

resources/test/fixtures/flake8_annotations/allow_star_arg_any.py

@@ -0,0 +1,57 @@
+from typing import Any
+
+
+# OK
+def foo(a: int, *args: str, **kwargs: str) -> int:
+    pass
+
+
+# ANN401
+def foo(a: Any, *args: str, **kwargs: str) -> int:
+    pass
+
+
+# ANN401
+def foo(a: int, *args: str, **kwargs: str) -> Any:
+    pass
+
+
+# OK
+def foo(a: int, *args: Any, **kwargs: Any) -> int:
+    pass
+
+
+# OK
+def foo(a: int, *args: Any, **kwargs: str) -> int:
+    pass
+
+
+# ANN401
+def foo(a: int, *args: str, **kwargs: Any) -> int:
+    pass
+
+
+class Bar:
+    # OK
+    def foo_method(self, a: int, *params: str, **options: str) -> int:
+        pass
+
+    # ANN401
+    def foo_method(self, a: Any, *params: str, **options: str) -> int:
+        pass
+
+    # ANN401
+    def foo_method(self, a: int, *params: str, **options: str) -> Any:
+        pass
+
+    # OK
+    def foo_method(self, a: int, *params: Any, **options: Any) -> int:
+        pass
+
+    # OK
+    def foo_method(self, a: int, *params: Any, **options: str) -> int:
+        pass
+
+    # OK
+    def foo_method(self, a: int, *params: str, **options: Any) -> int:
+        pass

resources/test/fixtures/flake8_annotations/annotation_presence.py

@@ -0,0 +1,105 @@
+from typing import Any, Type
+
+# Error
+def foo(a, b):
+    pass
+
+
+# Error
+def foo(a: int, b):
+    pass
+
+
+# Error
+def foo(a: int, b) -> int:
+    pass
+
+
+# Error
+def foo(a: int, b: int):
+    pass
+
+
+# Error
+def foo():
+    pass
+
+
+# OK
+def foo(a: int, b: int) -> int:
+    pass
+
+
+# OK
+def foo() -> int:
+    pass
+
+
+# OK
+def foo(a: int, *args: str, **kwargs: str) -> int:
+    pass
+
+
+# ANN401
+def foo(a: Any, *args: str, **kwargs: str) -> int:
+    pass
+
+
+# ANN401
+def foo(a: int, *args: str, **kwargs: str) -> Any:
+    pass
+
+
+# ANN401
+def foo(a: int, *args: Any, **kwargs: Any) -> int:
+    pass
+
+
+# ANN401
+def foo(a: int, *args: Any, **kwargs: str) -> int:
+    pass
+
+
+# ANN401
+def foo(a: int, *args: str, **kwargs: Any) -> int:
+    pass
+
+
+class Foo:
+    # OK
+    def foo(self: "Foo", a: int, b: int) -> int:
+        pass
+
+    # ANN101
+    def foo(self, a: int, b: int) -> int:
+        pass
+
+    # ANN401
+    def foo(self: "Foo", a: Any, *params: str, **options: str) -> int:
+        pass
+
+    # ANN401
+    def foo(self: "Foo", a: int, *params: str, **options: str) -> Any:
+        pass
+
+    # ANN401
+    def foo(self: "Foo", a: int, *params: Any, **options: Any) -> int:
+        pass
+
+    # ANN401
+    def foo(self: "Foo", a: int, *params: Any, **options: str) -> int:
+        pass
+
+    # ANN401
+    def foo(self: "Foo", a: int, *params: str, **options: Any) -> int:
+        pass
+
+    # OK
+    @classmethod
+    def foo(cls: Type["Foo"], a: int, b: int) -> int:
+        pass
+
+    # ANN102
+    @classmethod
+    def foo(cls, a: int, b: int) -> int:
+        pass

resources/test/fixtures/flake8_annotations/mypy_init_return.py

@@ -0,0 +1,41 @@
+"""Test case expected to be run with `mypy_init_return = True`."""
+
+# Error
+class Foo:
+    def __init__(self):
+        ...
+
+
+# Error
+class Foo:
+    def __init__(self, foo):
+        ...
+
+
+# OK
+class Foo:
+    def __init__(self, foo) -> None:
+        ...
+
+
+# OK
+class Foo:
+    def __init__(self) -> None:
+        ...
+
+
+# OK
+class Foo:
+    def __init__(self, foo: int):
+        ...
+
+
+# OK
+class Foo:
+    def __init__(self, foo: int) -> None:
+        ...
+
+
+# Error
+def __init__(self, foo: int):
+    ...

resources/test/fixtures/flake8_annotations/suppress_dummy_args.py

@@ -0,0 +1,26 @@
+"""Test case expected to be run with `suppress_dummy_args = True`."""
+
+# OK
+def foo(_) -> None:
+    ...
+
+
+# OK
+def foo(*_) -> None:
+    ...
+
+
+# OK
+def foo(**_) -> None:
+    ...
+
+
+# OK
+def foo(a: int, _) -> None:
+    ...
+
+
+# OK
+def foo() -> None:
+    def bar(_) -> None:
+        ...

resources/test/fixtures/flake8_annotations/suppress_none_returning.py

@@ -0,0 +1,55 @@
+"""Test case expected to be run with `suppress_none_returning = True`."""
+
+# OK
+def foo():
+    a = 2 + 2
+
+
+# OK
+def foo():
+    return
+
+
+# OK
+def foo():
+    return None
+
+
+# OK
+def foo():
+    a = 2 + 2
+    if a == 4:
+        return
+    else:
+        return
+
+
+# OK
+def foo():
+    a = 2 + 2
+    if a == 4:
+        return None
+    else:
+        return
+
+
+# OK
+def foo():
+    def bar() -> bool:
+        return True
+
+    bar()
+
+
+# Error
+def foo():
+    return True
+
+
+# Error
+def foo():
+    a = 2 + 2
+    if a == 4:
+        return True
+    else:
+        return

resources/test/fixtures/pyproject.toml

@@ -1,16 +1,36 @@
 [tool.ruff]
 line-length = 88
 extend-exclude = [
-    "excluded.py",
-    "migrations",
-    "directory/also_excluded.py",
-]
-per-file-ignores = [
-    "__init__.py:F401",
+  "excluded.py",
+  "migrations",
+  "directory/also_excluded.py",
 ]
+per-file-ignores = { "__init__.py" = ["F401"] }
 
 [tool.ruff.flake8-quotes]
 inline-quotes = "single"
 multiline-quotes = "double"
 docstring-quotes = "double"
 avoid-escape = true
+
+[tool.ruff.pep8-naming]
+ignore-names = [
+  "setUp",
+  "tearDown",
+  "setUpClass",
+  "tearDownClass",
+  "setUpModule",
+  "tearDownModule",
+  "asyncSetUp",
+  "asyncTearDown",
+  "setUpTestData",
+  "failureException",
+  "longMessage",
+  "maxDiff",
+]
+classmethod-decorators = [
+  "classmethod",
+]
+staticmethod-decorators = [
+  "staticmethod",
+]

ruff_dev/Cargo.toml

@@ -0,0 +1,16 @@
+[package]
+name = "ruff_dev"
+version = "0.0.108"
+edition = "2021"
+
+[dependencies]
+anyhow = { version = "1.0.60" }
+clap = { version = "4.0.1", features = ["derive"] }
+codegen = { version = "0.2.0" }
+itertools = { version = "0.10.5" }
+ruff = { path = ".." }
+rustpython-ast = { features = ["unparse"], git = "https://github.com/RustPython/RustPython.git", rev = "27bf82a2251d7e6ac6cd75e6ad51be12a53d84bb" }
+rustpython-common = { git = "https://github.com/RustPython/RustPython.git", rev = "27bf82a2251d7e6ac6cd75e6ad51be12a53d84bb" }
+rustpython-parser = { features = ["lalrpop"], git = "https://github.com/RustPython/RustPython.git", rev = "27bf82a2251d7e6ac6cd75e6ad51be12a53d84bb" }
+strum = { version = "0.24.1", features = ["strum_macros"] }
+strum_macros = { version = "0.24.3" }

ruff_dev/src/generate_check_code_prefix.rs

@@ -1,23 +1,39 @@
-//! Generate the CheckCodePrefix enum.
+//! Generate the `CheckCodePrefix` enum.
 
 use std::collections::{BTreeMap, BTreeSet};
+use std::fs::OpenOptions;
+use std::io::Write;
 
+use anyhow::Result;
+use clap::Parser;
 use codegen::{Scope, Type, Variant};
 use itertools::Itertools;
+use ruff::checks::CheckCode;
 use strum::IntoEnumIterator;
 
-use ruff::checks::CheckCode;
+const FILE: &str = "src/checks_gen.rs";
 
-fn main() {
+#[derive(Parser)]
+#[command(author, version, about, long_about = None)]
+pub struct Cli {
+    /// Write the generated source code to stdout (rather than to
+    /// `src/checks_gen.rs`).
+    #[arg(long)]
+    dry_run: bool,
+}
+
+pub fn main(cli: &Cli) -> Result<()> {
     // Build up a map from prefix to matching CheckCodes.
     let mut prefix_to_codes: BTreeMap<String, BTreeSet<CheckCode>> = Default::default();
     for check_code in CheckCode::iter() {
-        let as_ref = check_code.as_ref().to_string();
-        for i in 1..=as_ref.len() {
+        let as_ref: String = check_code.as_ref().to_string();
+        let prefix_len = as_ref
+            .chars()
+            .take_while(|char| char.is_alphabetic())
+            .count();
+        for i in prefix_len..=as_ref.len() {
             let prefix = as_ref[..i].to_string();
-            let entry = prefix_to_codes
-                .entry(prefix)
-                .or_insert_with(|| Default::default());
+            let entry = prefix_to_codes.entry(prefix).or_default();
             entry.insert(check_code.clone());
         }
     }
@@ -32,10 +48,12 @@ fn main() {
         .derive("Debug")
         .derive("PartialEq")
         .derive("Eq")
+        .derive("PartialOrd")
+        .derive("Ord")
         .derive("Clone")
         .derive("Serialize")
         .derive("Deserialize");
-    for (prefix, _) in &prefix_to_codes {
+    for prefix in prefix_to_codes.keys() {
         gen = gen.push_variant(Variant::new(prefix.to_string()));
     }
 
@@ -79,12 +97,13 @@ fn main() {
         .ret(Type::new("PrefixSpecificity"))
         .vis("pub")
         .line("match self {");
-    for (prefix, _) in &prefix_to_codes {
-        let specificity = match prefix.len() {
-            4 => "Explicit",
-            3 => "Tens",
-            2 => "Hundreds",
-            1 => "Category",
+    for prefix in prefix_to_codes.keys() {
+        let num_numeric = prefix.chars().filter(|char| char.is_numeric()).count();
+        let specificity = match num_numeric {
+            3 => "Explicit",
+            2 => "Tens",
+            1 => "Hundreds",
+            0 => "Category",
             _ => panic!("Invalid prefix: {}", prefix),
         };
         gen = gen.line(format!(
@@ -94,12 +113,28 @@ fn main() {
     }
     gen.line("}");
 
-    println!("//! File automatically generated by examples/generate_check_code_prefix.rs.");
-    println!();
-    println!("use serde::{{Deserialize, Serialize}};");
-    println!("use strum_macros::EnumString;");
-    println!();
-    println!("use crate::checks::CheckCode;");
-    println!();
-    println!("{}", scope.to_string());
+    // Construct the output contents.
+    let mut output = String::new();
+    output.push_str("//! File automatically generated by examples/generate_check_code_prefix.rs.");
+    output.push('\n');
+    output.push('\n');
+    output.push_str("use serde::{{Serialize, Deserialize}};");
+    output.push('\n');
+    output.push_str("use strum_macros::EnumString;");
+    output.push('\n');
+    output.push('\n');
+    output.push_str("use crate::checks::CheckCode;");
+    output.push('\n');
+    output.push('\n');
+    output.push_str(&scope.to_string());
+
+    // Write the output to `src/checks_gen.rs` (or stdout).
+    if cli.dry_run {
+        println!("{}", output);
+    } else {
+        let mut f = OpenOptions::new().write(true).truncate(true).open(FILE)?;
+        write!(f, "{}", output)?;
+    }
+
+    Ok(())
 }

ruff_dev/src/generate_rules_table.rs

@@ -0,0 +1,93 @@
+//! Generate a Markdown-compatible table of supported lint rules.
+
+use std::fs;
+use std::fs::OpenOptions;
+use std::io::Write;
+use std::path::PathBuf;
+
+use anyhow::Result;
+use clap::Args;
+use ruff::checks::{CheckCategory, CheckCode};
+use strum::IntoEnumIterator;
+
+const BEGIN_PRAGMA: &str = "<!-- Begin auto-generated sections. -->";
+const END_PRAGMA: &str = "<!-- End auto-generated sections. -->";
+
+#[derive(Args)]
+pub struct Cli {
+    /// Write the generated table to stdout (rather than to `README.md`).
+    #[arg(long)]
+    dry_run: bool,
+}
+
+pub fn main(cli: &Cli) -> Result<()> {
+    // Generate the table string.
+    let mut output = String::new();
+    for check_category in CheckCategory::iter() {
+        output.push_str(&format!("### {}", check_category.title()));
+        output.push('\n');
+        output.push('\n');
+
+        if let Some(url) = check_category.url() {
+            output.push_str(&format!(
+                "For more, see [{}]({}) on PyPI.",
+                check_category.title(),
+                url
+            ));
+            output.push('\n');
+            output.push('\n');
+        }
+
+        output.push_str("| Code | Name | Message | Fix |");
+        output.push('\n');
+        output.push_str("| ---- | ---- | ------- | --- |");
+        output.push('\n');
+
+        for check_code in CheckCode::iter() {
+            if check_code.category() == check_category {
+                let check_kind = check_code.kind();
+                let fix_token = if check_kind.fixable() { "🛠" } else { "" };
+                output.push_str(&format!(
+                    "| {} | {} | {} | {} |",
+                    check_kind.code().as_ref(),
+                    check_kind.as_ref(),
+                    check_kind.summary().replace('|', r"\|"),
+                    fix_token
+                ));
+                output.push('\n');
+            }
+        }
+        output.push('\n');
+    }
+
+    if cli.dry_run {
+        print!("{}", output);
+    } else {
+        // Read the existing file.
+        let file = PathBuf::from(env!("CARGO_MANIFEST_DIR"))
+            .parent()
+            .expect("Failed to find root directory")
+            .join("README.md");
+        let existing = fs::read_to_string(&file)?;
+
+        // Extract the prefix.
+        let index = existing
+            .find(BEGIN_PRAGMA)
+            .expect("Unable to find begin pragma.");
+        let prefix = &existing[..index + BEGIN_PRAGMA.len()];
+
+        // Extract the suffix.
+        let index = existing
+            .find(END_PRAGMA)
+            .expect("Unable to find end pragma.");
+        let suffix = &existing[index..];
+
+        // Write the prefix, new contents, and suffix.
+        let mut f = OpenOptions::new().write(true).truncate(true).open(&file)?;
+        write!(f, "{}\n\n", prefix)?;
+        write!(f, "{}", output)?;
+        write!(f, "{}", suffix)?;
+    }
+
+    Ok(())
+}

ruff_dev/src/generate_source_code.rs

@@ -1,26 +1,25 @@
+//! Run round-trip source code generation on a given Python file.
+
+use std::fs;
 use std::path::PathBuf;
 
 use anyhow::Result;
-use clap::Parser;
+use clap::Args;
+use ruff::code_gen::SourceGenerator;
 use rustpython_parser::parser;
 
-use ruff::code_gen::SourceGenerator;
-use ruff::fs;
-
-#[derive(Debug, Parser)]
-struct Cli {
+#[derive(Args)]
+pub struct Cli {
+    /// Python file to round-trip.
     #[arg(required = true)]
     file: PathBuf,
 }
 
-fn main() -> Result<()> {
-    let cli = Cli::parse();
-
-    let contents = fs::read_file(&cli.file)?;
+pub fn main(cli: &Cli) -> Result<()> {
+    let contents = fs::read_to_string(&cli.file)?;
     let python_ast = parser::parse_program(&contents, &cli.file.to_string_lossy())?;
     let mut generator = SourceGenerator::new();
     generator.unparse_suite(&python_ast)?;
     println!("{}", generator.generate()?);
-
     Ok(())
 }

ruff_dev/src/lib.rs

@@ -0,0 +1,5 @@
+pub mod generate_check_code_prefix;
+pub mod generate_rules_table;
+pub mod generate_source_code;
+pub mod print_ast;
+pub mod print_tokens;

ruff_dev/src/main.rs

@@ -0,0 +1,39 @@
+use anyhow::Result;
+use clap::{Parser, Subcommand};
+use ruff_dev::{
+    generate_check_code_prefix, generate_rules_table, generate_source_code, print_ast, print_tokens,
+};
+
+#[derive(Parser)]
+#[command(author, version, about, long_about = None)]
+#[command(propagate_version = true)]
+struct Cli {
+    #[command(subcommand)]
+    command: Commands,
+}
+
+#[derive(Subcommand)]
+enum Commands {
+    /// Generate the `CheckCodePrefix` enum.
+    GenerateCheckCodePrefix(generate_check_code_prefix::Cli),
+    /// Generate a Markdown-compatible table of supported lint rules.
+    GenerateRulesTable(generate_rules_table::Cli),
+    /// Run round-trip source code generation on a given Python file.
+    GenerateSourceCode(generate_source_code::Cli),
+    /// Print the AST for a given Python file.
+    PrintAST(print_ast::Cli),
+    /// Print the token stream for a given Python file.
+    PrintTokens(print_tokens::Cli),
+}
+
+fn main() -> Result<()> {
+    let cli = Cli::parse();
+    match &cli.command {
+        Commands::GenerateCheckCodePrefix(args) => generate_check_code_prefix::main(args)?,
+        Commands::GenerateRulesTable(args) => generate_rules_table::main(args)?,
+        Commands::GenerateSourceCode(args) => generate_source_code::main(args)?,
+        Commands::PrintAST(args) => print_ast::main(args)?,
+        Commands::PrintTokens(args) => print_tokens::main(args)?,
+    }
+    Ok(())
+}

ruff_dev/src/print_ast.rs

@@ -1,26 +1,22 @@
 //! Print the AST for a given Python file.
 
+use std::fs;
 use std::path::PathBuf;
 
 use anyhow::Result;
-use clap::Parser;
+use clap::Args;
 use rustpython_parser::parser;
 
-use ruff::fs;
-
-#[derive(Debug, Parser)]
-struct Cli {
+#[derive(Args)]
+pub struct Cli {
+    /// Python file for which to generate the AST.
     #[arg(required = true)]
     file: PathBuf,
 }
 
-fn main() -> Result<()> {
-    let cli = Cli::parse();
-
-    let contents = fs::read_file(&cli.file)?;
+pub fn main(cli: &Cli) -> Result<()> {
+    let contents = fs::read_to_string(&cli.file)?;
     let python_ast = parser::parse_program(&contents, &cli.file.to_string_lossy())?;
-
     println!("{:#?}", python_ast);
-
     Ok(())
 }

ruff_dev/src/print_tokens.rs

@@ -1,26 +1,23 @@
 //! Print the token stream for a given Python file.
 
+use std::fs;
 use std::path::PathBuf;
 
 use anyhow::Result;
-use clap::Parser;
+use clap::Args;
 use rustpython_parser::lexer;
 
-use ruff::fs;
-
-#[derive(Debug, Parser)]
-struct Cli {
+#[derive(Args)]
+pub struct Cli {
+    /// Python file for which to generate the AST.
     #[arg(required = true)]
     file: PathBuf,
 }
 
-fn main() -> Result<()> {
-    let cli = Cli::parse();
-
-    let contents = fs::read_file(&cli.file)?;
+pub fn main(cli: &Cli) -> Result<()> {
+    let contents = fs::read_to_string(&cli.file)?;
     for (_, tok, _) in lexer::make_tokenizer(&contents).flatten() {
         println!("{:#?}", tok);
     }
-
     Ok(())
 }

rust-toolchain

@@ -0,0 +1 @@
+1.65.0

rustfmt.toml

@@ -0,0 +1,15 @@
+condense_wildcard_suffixes = true
+edition = "2021"
+format_strings = true
+group_imports = "StdExternalCrate"
+hex_literal_case = "Lower"
+imports_granularity = "Module"
+max_width = 100
+normalize_comments = true
+normalize_doc_attributes = true
+reorder_impl_items = true
+reorder_imports = true
+reorder_modules = true
+unstable_features = true
+use_field_init_shorthand = true
+wrap_comments = true

scripts/.flake8

@@ -17,3 +17,5 @@ exclude =
     test_fstring.py,
     bad_coding2.py,
     badsyntax_*.py
+ignore_names = foo, bar
+quotes = double

src/ast/helpers.rs

@@ -1,9 +1,9 @@
+use std::collections::BTreeSet;
+
 use once_cell::sync::Lazy;
 use regex::Regex;
 use rustpython_ast::{Excepthandler, ExcepthandlerKind, Expr, ExprKind, Location, StmtKind};
 
-use crate::python::typing;
-
 fn compose_call_path_inner<'a>(expr: &'a Expr, parts: &mut Vec<&'a str>) {
     match &expr.node {
         ExprKind::Call { func, .. } => {
@@ -30,6 +30,7 @@ pub fn compose_call_path(expr: &Expr) -> Option<String> {
     }
 }
 
+/// Return `true` if the `Expr` is a name or attribute reference to `${target}`.
 pub fn match_name_or_attr(expr: &Expr, target: &str) -> bool {
     match &expr.node {
         ExprKind::Attribute { attr, .. } => target == attr,
@@ -38,40 +39,36 @@ pub fn match_name_or_attr(expr: &Expr, target: &str) -> bool {
     }
 }
 
-pub enum SubscriptKind {
-    AnnotatedSubscript,
-    PEP593AnnotatedSubscript,
-}
-
-pub fn match_annotated_subscript(expr: &Expr) -> Option<SubscriptKind> {
+/// Return `true` if the `Expr` is a reference to `${module}.${target}`.
+///
+/// Useful for, e.g., ensuring that a `Union` reference represents
+/// `typing.Union`.
+pub fn match_name_or_attr_from_module(
+    expr: &Expr,
+    target: &str,
+    module: &str,
+    imports: Option<&BTreeSet<&str>>,
+) -> bool {
     match &expr.node {
-        ExprKind::Attribute { attr, .. } => {
-            if typing::is_annotated_subscript(attr) {
-                Some(SubscriptKind::AnnotatedSubscript)
-            } else if typing::is_pep593_annotated_subscript(attr) {
-                Some(SubscriptKind::PEP593AnnotatedSubscript)
-            } else {
-                None
-            }
-        }
+        ExprKind::Attribute { value, attr, .. } => match &value.node {
+            ExprKind::Name { id, .. } => id == module && target == attr,
+            _ => false,
+        },
         ExprKind::Name { id, .. } => {
-            if typing::is_annotated_subscript(id) {
-                Some(SubscriptKind::AnnotatedSubscript)
-            } else if typing::is_pep593_annotated_subscript(id) {
-                Some(SubscriptKind::PEP593AnnotatedSubscript)
-            } else {
-                None
-            }
+            target == id
+                && imports
+                    .map(|imports| imports.contains(&id.as_str()))
+                    .unwrap_or_default()
         }
-        _ => None,
+        _ => false,
     }
 }
 
 static DUNDER_REGEX: Lazy<Regex> = Lazy::new(|| Regex::new(r"__[^\s]+__").unwrap());
 
 pub fn is_assignment_to_a_dunder(node: &StmtKind) -> bool {
-    // Check whether it's an assignment to a dunder, with or without a type annotation.
-    // This is what pycodestyle (as of 2.9.1) does.
+    // Check whether it's an assignment to a dunder, with or without a type
+    // annotation. This is what pycodestyle (as of 2.9.1) does.
     match node {
         StmtKind::Assign {
             targets,
@@ -132,12 +129,13 @@ pub fn is_super_call_with_arguments(func: &Expr, args: &[Expr]) -> bool {
     }
 }
 
-/// Convert a location within a file (relative to `base`) to an absolute position.
+/// Convert a location within a file (relative to `base`) to an absolute
+/// position.
 pub fn to_absolute(relative: &Location, base: &Location) -> Location {
     if relative.row() == 1 {
         Location::new(
             relative.row() + base.row() - 1,
-            relative.column() + base.column() - 1,
+            relative.column() + base.column(),
         )
     } else {
         Location::new(relative.row() + base.row() - 1, relative.column())

src/ast/operations.rs

@@ -1,6 +1,6 @@
-use rustpython_parser::ast::{Constant, Expr, ExprKind, Location, Stmt, StmtKind};
+use rustpython_parser::ast::{Constant, Expr, ExprKind, Stmt, StmtKind};
 
-use crate::ast::types::{BindingKind, Range, Scope};
+use crate::ast::types::{BindingKind, Scope};
 
 /// Extract the names bound to a given __all__ assignment.
 pub fn extract_all_names(stmt: &Stmt, scope: &Scope) -> Vec<String> {
@@ -117,82 +117,3 @@ pub fn is_unpacking_assignment(stmt: &Stmt) -> bool {
     }
     false
 }
-
-/// Struct used to efficiently slice source code at (row, column) Locations.
-pub struct SourceCodeLocator<'a> {
-    content: &'a str,
-    offsets: Vec<Vec<usize>>,
-}
-
-impl<'a> SourceCodeLocator<'a> {
-    pub fn new(content: &'a str) -> Self {
-        SourceCodeLocator {
-            content,
-            offsets: Self::compute_offsets(content),
-        }
-    }
-
-    fn compute_offsets(content: &str) -> Vec<Vec<usize>> {
-        let mut offsets = vec![];
-        let mut offset = 0;
-        for line in content.lines() {
-            let mut newline = 0;
-            let mut line_offsets: Vec<usize> = vec![];
-            for (i, char) in line.char_indices() {
-                line_offsets.push(offset + i);
-                newline = i + char.len_utf8();
-            }
-            line_offsets.push(offset + newline);
-            offsets.push(line_offsets);
-            offset += newline + 1;
-        }
-        offsets.push(vec![offset]);
-        offsets
-    }
-
-    pub fn slice_source_code_at(&self, location: &Location) -> &'a str {
-        let offset = self.offsets[location.row() - 1][location.column() - 1];
-        &self.content[offset..]
-    }
-
-    pub fn slice_source_code_range(&self, range: &Range) -> &'a str {
-        let start = self.offsets[range.location.row() - 1][range.location.column() - 1];
-        let end = self.offsets[range.end_location.row() - 1][range.end_location.column() - 1];
-        &self.content[start..end]
-    }
-
-    pub fn partition_source_code_at(
-        &self,
-        outer: &Range,
-        inner: &Range,
-    ) -> (&'a str, &'a str, &'a str) {
-        let outer_start = self.offsets[outer.location.row() - 1][outer.location.column() - 1];
-        let outer_end = self.offsets[outer.end_location.row() - 1][outer.end_location.column() - 1];
-        let inner_start = self.offsets[inner.location.row() - 1][inner.location.column() - 1];
-        let inner_end = self.offsets[inner.end_location.row() - 1][inner.end_location.column() - 1];
-        (
-            &self.content[outer_start..inner_start],
-            &self.content[inner_start..inner_end],
-            &self.content[inner_end..outer_end],
-        )
-    }
-}
-
-#[cfg(test)]
-mod tests {
-    use super::SourceCodeLocator;
-
-    #[test]
-    fn source_code_locator_init() {
-        let content = "# \u{4e9c}\nclass Foo:\n    \"\"\".\"\"\"";
-        let locator = SourceCodeLocator::new(content);
-        assert_eq!(locator.offsets.len(), 4);
-        assert_eq!(locator.offsets[0], [0, 1, 2, 5]);
-        assert_eq!(locator.offsets[1], [6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16]);
-        assert_eq!(
-            locator.offsets[2],
-            [17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28]
-        );
-        assert_eq!(locator.offsets[3], [29]);
-    }
-}

src/ast/relocate.rs

@@ -8,7 +8,8 @@ fn relocate_keyword(keyword: &mut Keyword, location: Range) {
     relocate_expr(&mut keyword.node.value, location);
 }
 
-/// Change an expression's location (recursively) to match a desired, fixed location.
+/// Change an expression's location (recursively) to match a desired, fixed
+/// location.
 pub fn relocate_expr(expr: &mut Expr, location: Range) {
     expr.location = location.location;
     expr.end_location = Some(location.end_location);

src/ast/types.rs

@@ -1,6 +1,7 @@
 use std::collections::BTreeMap;
 use std::sync::atomic::{AtomicUsize, Ordering};
 
+use rustpython_ast::{Expr, Keyword};
 use rustpython_parser::ast::{Located, Location};
 
 fn id() -> usize {
@@ -30,24 +31,33 @@ pub struct FunctionScope {
     pub uses_locals: bool,
 }
 
-#[derive(Clone, Debug)]
-pub enum ScopeKind {
-    Class,
-    Function(FunctionScope),
-    Generator,
-    Module,
+#[derive(Clone, Debug, Default)]
+pub struct ClassScope<'a> {
+    pub name: &'a str,
+    pub bases: &'a [Expr],
+    pub keywords: &'a [Keyword],
+    pub decorator_list: &'a [Expr],
 }
 
 #[derive(Clone, Debug)]
-pub struct Scope {
+pub enum ScopeKind<'a> {
+    Class(ClassScope<'a>),
+    Function(FunctionScope),
+    Generator,
+    Module,
+    Arg,
+}
+
+#[derive(Clone, Debug)]
+pub struct Scope<'a> {
     pub id: usize,
-    pub kind: ScopeKind,
+    pub kind: ScopeKind<'a>,
     pub import_starred: bool,
     pub values: BTreeMap<String, Binding>,
 }
 
-impl Scope {
-    pub fn new(kind: ScopeKind) -> Self {
+impl<'a> Scope<'a> {
+    pub fn new(kind: ScopeKind<'a>) -> Self {
         Scope {
             id: id(),
             kind,
@@ -85,15 +95,11 @@ pub enum BindingKind {
 pub struct Binding {
     pub kind: BindingKind,
     pub range: Range,
-    /// Tuple of (scope index, range) indicating the scope and range at which the binding was
-    /// last used.
+    /// Tuple of (scope index, range) indicating the scope and range at which
+    /// the binding was last used.
     pub used: Option<(usize, Range)>,
 }
 
-pub trait CheckLocator {
-    fn locate_check(&self, default: Range) -> Range;
-}
-
 #[derive(Clone, Copy, Debug, PartialEq, Eq, PartialOrd, Ord)]
 pub enum ImportKind {
     Import,

src/autofix/fixer.rs

@@ -1,12 +1,17 @@
+use std::borrow::Cow;
 use std::collections::BTreeSet;
 
 use itertools::Itertools;
+use ropey::RopeBuilder;
 use rustpython_parser::ast::Location;
 
-use crate::autofix::Fix;
-use crate::autofix::Patch;
+use crate::ast::types::Range;
+use crate::autofix::{Fix, Patch};
 use crate::checks::Check;
+use crate::source_code_locator::SourceCodeLocator;
 
+// TODO(charlie): The model here is awkward because `Apply` is only relevant at
+// higher levels in the execution flow.
 #[derive(Hash)]
 pub enum Mode {
     Generate,
@@ -35,77 +40,64 @@ impl From<bool> for Mode {
 }
 
 /// Auto-fix errors in a file, and write the fixed source code to disk.
-pub fn fix_file(checks: &mut [Check], contents: &str) -> Option<String> {
+pub fn fix_file<'a>(
+    checks: &'a mut [Check],
+    locator: &'a SourceCodeLocator<'a>,
+) -> Option<Cow<'a, str>> {
     if checks.iter().all(|check| check.fix.is_none()) {
         return None;
     }
 
     Some(apply_fixes(
         checks.iter_mut().filter_map(|check| check.fix.as_mut()),
-        contents,
+        locator,
     ))
 }
 
 /// Apply a series of fixes.
-fn apply_fixes<'a>(fixes: impl Iterator<Item = &'a mut Fix>, contents: &str) -> String {
-    let lines: Vec<&str> = contents.lines().collect();
-
-    let mut output: String = Default::default();
-    let mut last_pos: Location = Default::default();
-    let mut applied: BTreeSet<&Patch> = Default::default();
+fn apply_fixes<'a>(
+    fixes: impl Iterator<Item = &'a mut Fix>,
+    locator: &'a SourceCodeLocator<'a>,
+) -> Cow<'a, str> {
+    let mut output = RopeBuilder::new();
+    let mut last_pos: Location = Location::new(1, 0);
+    let mut applied: BTreeSet<&Patch> = BTreeSet::new();
 
     for fix in fixes.sorted_by_key(|fix| fix.patch.location) {
-        // If we already applied an identical fix as part of another correction, skip any
-        // re-application.
+        // If we already applied an identical fix as part of another correction, skip
+        // any re-application.
         if applied.contains(&fix.patch) {
             fix.applied = true;
             continue;
         }
 
-        // Best-effort approach: if this fix overlaps with a fix we've already applied, skip it.
+        // Best-effort approach: if this fix overlaps with a fix we've already applied,
+        // skip it.
         if last_pos > fix.patch.location {
             continue;
         }
 
-        if fix.patch.location.row() > last_pos.row() {
-            if last_pos.row() > 0 || last_pos.column() > 0 {
-                output.push_str(&lines[last_pos.row() - 1][last_pos.column() - 1..]);
-                output.push('\n');
-            }
-            for line in &lines[last_pos.row()..fix.patch.location.row() - 1] {
-                output.push_str(line);
-                output.push('\n');
-            }
-            output
-                .push_str(&lines[fix.patch.location.row() - 1][..fix.patch.location.column() - 1]);
-            output.push_str(&fix.patch.content);
-        } else {
-            output.push_str(
-                &lines[last_pos.row() - 1][last_pos.column() - 1..fix.patch.location.column() - 1],
-            );
-            output.push_str(&fix.patch.content);
-        }
-        last_pos = fix.patch.end_location;
+        // Add all contents from `last_pos` to `fix.patch.location`.
+        let slice = locator.slice_source_code_range(&Range {
+            location: last_pos,
+            end_location: fix.patch.location,
+        });
+        output.append(&slice);
 
+        // Add the patch itself.
+        output.append(&fix.patch.content);
+
+        // Track that the fix was applied.
+        last_pos = fix.patch.end_location;
         applied.insert(&fix.patch);
         fix.applied = true;
     }
 
-    if last_pos.row() > 0
-        && (last_pos.row() - 1) < lines.len()
-        && (last_pos.row() > 0 || last_pos.column() > 0)
-    {
-        output.push_str(&lines[last_pos.row() - 1][last_pos.column() - 1..]);
-        output.push('\n');
-    }
-    if last_pos.row() < lines.len() {
-        for line in &lines[last_pos.row()..] {
-            output.push_str(line);
-            output.push('\n');
-        }
-    }
+    // Add the remaining content.
+    let slice = locator.slice_source_code_at(&last_pos);
+    output.append(&slice);
 
-    output
+    Cow::from(output.finish())
 }
 
 #[cfg(test)]
@@ -114,13 +106,14 @@ mod tests {
     use rustpython_parser::ast::Location;
 
     use crate::autofix::fixer::apply_fixes;
-    use crate::autofix::Fix;
-    use crate::autofix::Patch;
+    use crate::autofix::{Fix, Patch};
+    use crate::SourceCodeLocator;
 
     #[test]
     fn empty_file() -> Result<()> {
         let mut fixes = vec![];
-        let actual = apply_fixes(fixes.iter_mut(), "");
+        let locator = SourceCodeLocator::new("");
+        let actual = apply_fixes(fixes.iter_mut(), &locator);
         let expected = "";
 
         assert_eq!(actual, expected);
@@ -133,17 +126,17 @@ mod tests {
         let mut fixes = vec![Fix {
             patch: Patch {
                 content: "Bar".to_string(),
-                location: Location::new(1, 9),
-                end_location: Location::new(1, 15),
+                location: Location::new(1, 8),
+                end_location: Location::new(1, 14),
             },
             applied: false,
         }];
-        let actual = apply_fixes(
-            fixes.iter_mut(),
+        let locator = SourceCodeLocator::new(
             "class A(object):
         ...
 ",
         );
+        let actual = apply_fixes(fixes.iter_mut(), &locator);
 
         let expected = "class A(Bar):
         ...
@@ -159,17 +152,17 @@ mod tests {
         let mut fixes = vec![Fix {
             patch: Patch {
                 content: "".to_string(),
-                location: Location::new(1, 8),
-                end_location: Location::new(1, 16),
+                location: Location::new(1, 7),
+                end_location: Location::new(1, 15),
             },
             applied: false,
         }];
-        let actual = apply_fixes(
-            fixes.iter_mut(),
+        let locator = SourceCodeLocator::new(
             "class A(object):
         ...
 ",
         );
+        let actual = apply_fixes(fixes.iter_mut(), &locator);
 
         let expected = "class A:
         ...
@@ -186,26 +179,26 @@ mod tests {
             Fix {
                 patch: Patch {
                     content: "".to_string(),
-                    location: Location::new(1, 8),
-                    end_location: Location::new(1, 17),
+                    location: Location::new(1, 7),
+                    end_location: Location::new(1, 16),
                 },
                 applied: false,
             },
             Fix {
                 patch: Patch {
                     content: "".to_string(),
-                    location: Location::new(1, 17),
-                    end_location: Location::new(1, 24),
+                    location: Location::new(1, 16),
+                    end_location: Location::new(1, 23),
                 },
                 applied: false,
             },
         ];
-        let actual = apply_fixes(
-            fixes.iter_mut(),
+        let locator = SourceCodeLocator::new(
             "class A(object, object):
         ...
 ",
         );
+        let actual = apply_fixes(fixes.iter_mut(), &locator);
 
         let expected = "class A:
         ...
@@ -222,26 +215,26 @@ mod tests {
             Fix {
                 patch: Patch {
                     content: "".to_string(),
-                    location: Location::new(1, 8),
-                    end_location: Location::new(1, 16),
+                    location: Location::new(1, 7),
+                    end_location: Location::new(1, 15),
                 },
                 applied: false,
             },
             Fix {
                 patch: Patch {
                     content: "ignored".to_string(),
-                    location: Location::new(1, 10),
-                    end_location: Location::new(1, 12),
+                    location: Location::new(1, 9),
+                    end_location: Location::new(1, 11),
                 },
                 applied: false,
             },
         ];
-        let actual = apply_fixes(
-            fixes.iter_mut(),
+        let locator = SourceCodeLocator::new(
             "class A(object):
     ...
 ",
         );
+        let actual = apply_fixes(fixes.iter_mut(), &locator);
 
         let expected = "class A:
     ...

src/autofix/helpers.rs

@@ -4,7 +4,8 @@ use rustpython_parser::ast::{ExcepthandlerKind, Location, Stmt, StmtKind};
 
 use crate::autofix::Fix;
 
-/// Determine if a body contains only a single statement, taking into account deleted.
+/// Determine if a body contains only a single statement, taking into account
+/// deleted.
 fn has_single_child(body: &[Stmt], deleted: &[&Stmt]) -> bool {
     body.iter().filter(|child| !deleted.contains(child)).count() == 1
 }
@@ -80,10 +81,11 @@ pub fn remove_stmt(stmt: &Stmt, parent: Option<&Stmt>, deleted: &[&Stmt]) -> Res
         ))
     } else {
         // Otherwise, nuke the entire line.
-        // TODO(charlie): This logic assumes that there are no multi-statement physical lines.
+        // TODO(charlie): This logic assumes that there are no multi-statement physical
+        // lines.
         Ok(Fix::deletion(
-            Location::new(stmt.location.row(), 1),
-            Location::new(stmt.end_location.unwrap().row() + 1, 1),
+            Location::new(stmt.location.row(), 0),
+            Location::new(stmt.end_location.unwrap().row() + 1, 0),
         ))
     }
 }

src/cache.rs

@@ -1,4 +1,5 @@
-// cacache uses asyncd-std which has no wasm support, so currently no caching support on wasm
+// cacache uses asyncd-std which has no wasm support, so currently no caching
+// support on wasm
 #![cfg_attr(
     target_family = "wasm",
     allow(unused_imports, unused_variables, dead_code)
@@ -127,7 +128,7 @@ pub fn get(
             }
             Err(e) => error!("Failed to deserialize encoded cache entry: {e:?}"),
         },
-        Err(EntryNotFound(_, _)) => {}
+        Err(EntryNotFound(..)) => {}
         Err(e) => error!("Failed to read from cache: {e:?}"),
     }
     None

src/check_lines.rs

@@ -2,16 +2,21 @@
 
 use std::collections::BTreeMap;
 
+use once_cell::sync::Lazy;
+use regex::Regex;
 use rustpython_parser::ast::Location;
 
 use crate::ast::types::Range;
-use crate::autofix::fixer;
-use crate::autofix::Fix;
+use crate::autofix::{fixer, Fix};
 use crate::checks::{Check, CheckCode, CheckKind};
 use crate::noqa;
 use crate::noqa::Directive;
 use crate::settings::Settings;
 
+// Regex from PEP263
+static CODING_COMMENT_REGEX: Lazy<Regex> =
+    Lazy::new(|| Regex::new(r"^[ \t\f]*#.*?coding[:=][ \t]*utf-?8").expect("Invalid regex"));
+
 /// Whether the given line is too long and should be reported.
 fn should_enforce_line_length(line: &str, length: usize, limit: usize) -> bool {
     if length > limit {
@@ -35,6 +40,7 @@ pub fn check_lines(
     settings: &Settings,
     autofix: &fixer::Mode,
 ) {
+    let enforce_unnecessary_coding_comment = settings.enabled.contains(&CheckCode::U009);
     let enforce_line_too_long = settings.enabled.contains(&CheckCode::E501);
     let enforce_noqa = settings.enabled.contains(&CheckCode::M001);
 
@@ -53,6 +59,30 @@ pub fn check_lines(
             .map(|lineno| lineno - 1)
             .unwrap_or(lineno);
 
+        // Enforce unnecessary coding comments (U009).
+        if enforce_unnecessary_coding_comment {
+            if lineno < 2 {
+                // PEP3120 makes utf-8 the default encoding.
+                if CODING_COMMENT_REGEX.is_match(line) {
+                    let line_length = line.len();
+                    let mut check = Check::new(
+                        CheckKind::PEP3120UnnecessaryCodingComment,
+                        Range {
+                            location: Location::new(lineno + 1, 0),
+                            end_location: Location::new(lineno + 1, line_length + 1),
+                        },
+                    );
+                    if autofix.patch() {
+                        check.amend(Fix::deletion(
+                            Location::new(lineno + 1, 0),
+                            Location::new(lineno + 1, line_length + 1),
+                        ));
+                    }
+                    line_checks.push(check);
+                }
+            }
+        }
+
         if enforce_noqa {
             noqa_directives
                 .entry(noqa_lineno)
@@ -68,7 +98,7 @@ pub fn check_lines(
                     .or_insert_with(|| (noqa::extract_noqa_directive(lines[noqa_lineno]), vec![]));
 
                 match noqa {
-                    (Directive::All(_, _), matches) => {
+                    (Directive::All(..), matches) => {
                         matches.push(check.kind.code().as_ref());
                         ignored.push(index)
                     }
@@ -83,7 +113,7 @@ pub fn check_lines(
             }
         }
 
-        // Enforce line length.
+        // Enforce line length violations (E501).
         if enforce_line_too_long {
             let line_length = line.chars().count();
             if should_enforce_line_length(line, line_length, settings.line_length) {
@@ -94,13 +124,13 @@ pub fn check_lines(
                 let check = Check::new(
                     CheckKind::LineTooLong(line_length, settings.line_length),
                     Range {
-                        location: Location::new(lineno + 1, 1),
-                        end_location: Location::new(lineno + 1, line_length + 1),
+                        location: Location::new(lineno + 1, 0),
+                        end_location: Location::new(lineno + 1, line_length),
                     },
                 );
 
                 match noqa {
-                    (Directive::All(_, _), matches) => {
+                    (Directive::All(..), matches) => {
                         matches.push(check.kind.code().as_ref());
                     }
                     (Directive::Codes(_, _, codes), matches) => {
@@ -118,8 +148,8 @@ pub fn check_lines(
 
     // Enforce newlines at end of files.
     if settings.enabled.contains(&CheckCode::W292) && !contents.ends_with('\n') {
-        // Note: if `lines.last()` is `None`, then `contents` is empty (and so we don't want to
-        // raise W292 anyway).
+        // Note: if `lines.last()` is `None`, then `contents` is empty (and so we don't
+        // want to raise W292 anyway).
         if let Some(line) = lines.last() {
             let lineno = lines.len() - 1;
             let noqa_lineno = noqa_line_for
@@ -140,7 +170,7 @@ pub fn check_lines(
             );
 
             match noqa {
-                (Directive::All(_, _), matches) => {
+                (Directive::All(..), matches) => {
                     matches.push(check.kind.code().as_ref());
                 }
                 (Directive::Codes(_, _, codes), matches) => {
@@ -164,14 +194,14 @@ pub fn check_lines(
                         let mut check = Check::new(
                             CheckKind::UnusedNOQA(None),
                             Range {
-                                location: Location::new(row + 1, start + 1),
-                                end_location: Location::new(row + 1, end + 1),
+                                location: Location::new(row + 1, start),
+                                end_location: Location::new(row + 1, end),
                             },
                         );
                         if autofix.patch() {
                             check.amend(Fix::deletion(
-                                Location::new(row + 1, start + 1),
-                                Location::new(row + 1, lines[row].chars().count() + 1),
+                                Location::new(row + 1, start),
+                                Location::new(row + 1, lines[row].chars().count()),
                             ));
                         }
                         line_checks.push(check);
@@ -192,21 +222,21 @@ pub fn check_lines(
                         let mut check = Check::new(
                             CheckKind::UnusedNOQA(Some(invalid_codes)),
                             Range {
-                                location: Location::new(row + 1, start + 1),
-                                end_location: Location::new(row + 1, end + 1),
+                                location: Location::new(row + 1, start),
+                                end_location: Location::new(row + 1, end),
                             },
                         );
                         if autofix.patch() {
                             if valid_codes.is_empty() {
                                 check.amend(Fix::deletion(
-                                    Location::new(row + 1, start + 1),
-                                    Location::new(row + 1, lines[row].chars().count() + 1),
+                                    Location::new(row + 1, start),
+                                    Location::new(row + 1, lines[row].chars().count()),
                                 ));
                             } else {
                                 check.amend(Fix::replacement(
                                     format!("  # noqa: {}", valid_codes.join(", ")),
-                                    Location::new(row + 1, start + 1),
-                                    Location::new(row + 1, lines[row].chars().count() + 1),
+                                    Location::new(row + 1, start),
+                                    Location::new(row + 1, lines[row].chars().count()),
                                 ));
                             }
                         }
@@ -227,12 +257,11 @@ pub fn check_lines(
 
 #[cfg(test)]
 mod tests {
+    use super::check_lines;
     use crate::autofix::fixer;
     use crate::checks::{Check, CheckCode};
     use crate::settings::Settings;
 
-    use super::check_lines;
-
     #[test]
     fn e501_non_ascii_char() {
         let line = "'\u{4e9c}' * 2"; // 7 in UTF-32, 9 in UTF-8.

src/check_tokens.rs

@@ -2,43 +2,67 @@
 
 use rustpython_parser::lexer::{LexResult, Tok};
 
-use crate::ast::operations::SourceCodeLocator;
+use crate::autofix::fixer;
 use crate::checks::{Check, CheckCode};
-use crate::flake8_quotes::docstring_detection::StateMachine;
-use crate::{flake8_quotes, pycodestyle, Settings};
+use crate::lex::docstring_detection::StateMachine;
+use crate::rules::checks::Context;
+use crate::source_code_locator::SourceCodeLocator;
+use crate::{flake8_quotes, pycodestyle, rules, Settings};
 
 pub fn check_tokens(
     checks: &mut Vec<Check>,
-    contents: &str,
+    locator: &SourceCodeLocator,
     tokens: &[LexResult],
     settings: &Settings,
+    autofix: &fixer::Mode,
 ) {
-    let enforce_invalid_escape_sequence = settings.enabled.contains(&CheckCode::W605);
+    let enforce_ambiguous_unicode_character = settings.enabled.contains(&CheckCode::RUF001)
+        || settings.enabled.contains(&CheckCode::RUF002)
+        || settings.enabled.contains(&CheckCode::RUF003);
     let enforce_quotes = settings.enabled.contains(&CheckCode::Q000)
-        | settings.enabled.contains(&CheckCode::Q001)
-        | settings.enabled.contains(&CheckCode::Q002)
-        | settings.enabled.contains(&CheckCode::Q003);
+        || settings.enabled.contains(&CheckCode::Q001)
+        || settings.enabled.contains(&CheckCode::Q002)
+        || settings.enabled.contains(&CheckCode::Q003);
+    let enforce_invalid_escape_sequence = settings.enabled.contains(&CheckCode::W605);
 
-    // TODO(charlie): Use a shared SourceCodeLocator between this site and the AST traversal.
-    let locator = SourceCodeLocator::new(contents);
-
-    let mut state_machine = StateMachine::new();
+    let mut state_machine: StateMachine = Default::default();
     for (start, tok, end) in tokens.iter().flatten() {
-        // W605
-        if enforce_invalid_escape_sequence {
-            if matches!(tok, Tok::String { .. }) {
-                checks.extend(pycodestyle::checks::invalid_escape_sequence(
-                    &locator, start, end,
-                ));
+        let is_docstring = if enforce_ambiguous_unicode_character || enforce_quotes {
+            state_machine.consume(tok)
+        } else {
+            false
+        };
+
+        // RUF001, RUF002, RUF003
+        if enforce_ambiguous_unicode_character {
+            if matches!(tok, Tok::String { .. } | Tok::Comment) {
+                for check in rules::checks::ambiguous_unicode_character(
+                    locator,
+                    start,
+                    end,
+                    if matches!(tok, Tok::String { .. }) {
+                        if is_docstring {
+                            Context::Docstring
+                        } else {
+                            Context::String
+                        }
+                    } else {
+                        Context::Comment
+                    },
+                    autofix.patch(),
+                ) {
+                    if settings.enabled.contains(check.kind.code()) {
+                        checks.push(check);
+                    }
+                }
             }
         }
 
         // flake8-quotes
         if enforce_quotes {
-            let is_docstring = state_machine.consume(tok);
             if matches!(tok, Tok::String { .. }) {
                 if let Some(check) = flake8_quotes::checks::quotes(
-                    &locator,
+                    locator,
                     start,
                     end,
                     is_docstring,
@@ -50,5 +74,14 @@ pub fn check_tokens(
                 }
             }
         }
+
+        // W605
+        if enforce_invalid_escape_sequence {
+            if matches!(tok, Tok::String { .. }) {
+                checks.extend(pycodestyle::checks::invalid_escape_sequence(
+                    locator, start, end,
+                ));
+            }
+        }
     }
 }

src/checks.rs

@@ -78,11 +78,19 @@ pub enum CheckCode {
     A003,
     // flake8-bugbear
     B002,
+    B003,
+    B004,
+    B005,
+    B006,
     B007,
+    B008,
     B011,
     B013,
     B014,
+    B015,
+    B016,
     B017,
+    B018,
     B025,
     // flake8-comprehensions
     C400,
@@ -109,6 +117,18 @@ pub enum CheckCode {
     Q001,
     Q002,
     Q003,
+    // flake8-annotations
+    ANN001,
+    ANN002,
+    ANN003,
+    ANN101,
+    ANN102,
+    ANN201,
+    ANN202,
+    ANN204,
+    ANN205,
+    ANN206,
+    ANN401,
     // pyupgrade
     U001,
     U002,
@@ -118,6 +138,8 @@ pub enum CheckCode {
     U006,
     U007,
     U008,
+    U009,
+    U010,
     // pydocstyle
     D100,
     D101,
@@ -179,6 +201,10 @@ pub enum CheckCode {
     N816,
     N817,
     N818,
+    // Ruff
+    RUF001,
+    RUF002,
+    RUF003,
     // Meta
     M001,
 }
@@ -186,8 +212,7 @@ pub enum CheckCode {
 #[derive(EnumIter, Debug, PartialEq, Eq)]
 pub enum CheckCategory {
     Pyflakes,
-    PycodestyleError,
-    PycodestyleWarning,
+    Pycodestyle,
     Pydocstyle,
     Pyupgrade,
     PEP8Naming,
@@ -196,26 +221,55 @@ pub enum CheckCategory {
     Flake8Builtins,
     Flake8Print,
     Flake8Quotes,
+    Flake8Annotations,
+    Ruff,
     Meta,
 }
 
 impl CheckCategory {
     pub fn title(&self) -> &'static str {
         match self {
-            CheckCategory::PycodestyleError => "pycodestyle (error)",
-            CheckCategory::PycodestyleWarning => "pycodestyle (warning)",
+            CheckCategory::Pycodestyle => "pycodestyle",
             CheckCategory::Pyflakes => "Pyflakes",
             CheckCategory::Flake8Builtins => "flake8-builtins",
             CheckCategory::Flake8Bugbear => "flake8-bugbear",
             CheckCategory::Flake8Comprehensions => "flake8-comprehensions",
             CheckCategory::Flake8Print => "flake8-print",
             CheckCategory::Flake8Quotes => "flake8-quotes",
+            CheckCategory::Flake8Annotations => "flake8-annotations",
             CheckCategory::Pyupgrade => "pyupgrade",
             CheckCategory::Pydocstyle => "pydocstyle",
             CheckCategory::PEP8Naming => "pep8-naming",
+            CheckCategory::Ruff => "Ruff-specific rules",
             CheckCategory::Meta => "Meta rules",
         }
     }
+
+    pub fn url(&self) -> Option<&'static str> {
+        match self {
+            CheckCategory::Pycodestyle => Some("https://pypi.org/project/pycodestyle/2.9.1/"),
+            CheckCategory::Pyflakes => Some("https://pypi.org/project/pyflakes/2.5.0/"),
+            CheckCategory::Flake8Builtins => {
+                Some("https://pypi.org/project/flake8-builtins/2.0.1/")
+            }
+            CheckCategory::Flake8Bugbear => {
+                Some("https://pypi.org/project/flake8-bugbear/22.10.27/")
+            }
+            CheckCategory::Flake8Comprehensions => {
+                Some("https://pypi.org/project/flake8-comprehensions/3.10.1/")
+            }
+            CheckCategory::Flake8Print => Some("https://pypi.org/project/flake8-print/5.0.0/"),
+            CheckCategory::Flake8Quotes => Some("https://pypi.org/project/flake8-quotes/3.3.1/"),
+            CheckCategory::Flake8Annotations => {
+                Some("https://pypi.org/project/flake8-annotations/2.9.1/")
+            }
+            CheckCategory::Pyupgrade => Some("https://pypi.org/project/pyupgrade/3.2.0/"),
+            CheckCategory::Pydocstyle => Some("https://pypi.org/project/pydocstyle/6.1.1/"),
+            CheckCategory::PEP8Naming => Some("https://pypi.org/project/pep8-naming/0.13.2/"),
+            CheckCategory::Ruff => None,
+            CheckCategory::Meta => None,
+        }
+    }
 }
 
 #[allow(clippy::upper_case_acronyms)]
@@ -287,11 +341,19 @@ pub enum CheckKind {
     BuiltinAttributeShadowing(String),
     // flake8-bugbear
     UnaryPrefixIncrement,
+    AssignmentToOsEnviron,
+    UnreliableCallableCheck,
+    StripWithMultiCharacters,
+    MutableArgumentDefault,
     UnusedLoopControlVariable(String),
+    FunctionCallArgumentDefault,
     DoNotAssertFalse,
     RedundantTupleInExceptionHandler(String),
     DuplicateHandlerException(Vec<String>),
+    UselessComparison,
+    CannotRaiseLiteral,
     NoAssertRaisesException,
+    UselessExpression,
     DuplicateTryBlockException(String),
     // flake8-comprehensions
     UnnecessaryGeneratorList,
@@ -318,6 +380,18 @@ pub enum CheckKind {
     BadQuotesMultilineString(Quote),
     BadQuotesDocstring(Quote),
     AvoidQuoteEscape,
+    // flake8-annotations
+    MissingTypeFunctionArgument(String),
+    MissingTypeArgs(String),
+    MissingTypeKwargs(String),
+    MissingTypeSelf(String),
+    MissingTypeCls(String),
+    MissingReturnTypePublicFunction(String),
+    MissingReturnTypePrivateFunction(String),
+    MissingReturnTypeMagicMethod(String),
+    MissingReturnTypeStaticMethod(String),
+    MissingReturnTypeClassMethod(String),
+    DynamicallyTypedExpression(String),
     // pyupgrade
     TypeOfPrimitive(Primitive),
     UnnecessaryAbspath,
@@ -327,6 +401,8 @@ pub enum CheckKind {
     UsePEP585Annotation(String),
     UsePEP604Annotation,
     SuperCallWithParameters,
+    PEP3120UnnecessaryCodingComment,
+    UnnecessaryFutureImport(String),
     // pydocstyle
     BlankLineAfterLastSection(String),
     BlankLineAfterSection(String),
@@ -388,20 +464,30 @@ pub enum CheckKind {
     MixedCaseVariableInGlobalScope(String),
     CamelcaseImportedAsAcronym(String, String),
     ErrorSuffixOnExceptionName(String),
+    // Ruff
+    AmbiguousUnicodeCharacterString(char, char),
+    AmbiguousUnicodeCharacterDocstring(char, char),
+    AmbiguousUnicodeCharacterComment(char, char),
     // Meta
     UnusedNOQA(Option<Vec<String>>),
 }
 
 impl CheckCode {
-    /// The source for the check (either the AST, the filesystem, or the physical lines).
+    /// The source for the check (either the AST, the filesystem, or the
+    /// physical lines).
     pub fn lint_source(&self) -> &'static LintSource {
         match self {
-            CheckCode::E501 | CheckCode::W292 | CheckCode::M001 => &LintSource::Lines,
-            CheckCode::W605
-            | CheckCode::Q000
+            CheckCode::E501 | CheckCode::W292 | CheckCode::M001 | CheckCode::U009 => {
+                &LintSource::Lines
+            }
+            CheckCode::Q000
             | CheckCode::Q001
             | CheckCode::Q002
-            | CheckCode::Q003 => &LintSource::Tokens,
+            | CheckCode::Q003
+            | CheckCode::W605
+            | CheckCode::RUF001
+            | CheckCode::RUF002
+            | CheckCode::RUF003 => &LintSource::Tokens,
             CheckCode::E902 => &LintSource::FileSystem,
             _ => &LintSource::AST,
         }
@@ -465,13 +551,21 @@ impl CheckCode {
             CheckCode::A003 => CheckKind::BuiltinAttributeShadowing("...".to_string()),
             // flake8-bugbear
             CheckCode::B002 => CheckKind::UnaryPrefixIncrement,
+            CheckCode::B003 => CheckKind::AssignmentToOsEnviron,
+            CheckCode::B004 => CheckKind::UnreliableCallableCheck,
+            CheckCode::B005 => CheckKind::StripWithMultiCharacters,
+            CheckCode::B006 => CheckKind::MutableArgumentDefault,
             CheckCode::B007 => CheckKind::UnusedLoopControlVariable("i".to_string()),
+            CheckCode::B008 => CheckKind::FunctionCallArgumentDefault,
             CheckCode::B011 => CheckKind::DoNotAssertFalse,
             CheckCode::B013 => {
                 CheckKind::RedundantTupleInExceptionHandler("ValueError".to_string())
             }
             CheckCode::B014 => CheckKind::DuplicateHandlerException(vec!["ValueError".to_string()]),
+            CheckCode::B015 => CheckKind::UselessComparison,
+            CheckCode::B016 => CheckKind::CannotRaiseLiteral,
             CheckCode::B017 => CheckKind::NoAssertRaisesException,
+            CheckCode::B018 => CheckKind::UselessExpression,
             CheckCode::B025 => CheckKind::DuplicateTryBlockException("Exception".to_string()),
             // flake8-comprehensions
             CheckCode::C400 => CheckKind::UnnecessaryGeneratorList,
@@ -511,6 +605,18 @@ impl CheckCode {
             CheckCode::Q001 => CheckKind::BadQuotesMultilineString(Quote::Double),
             CheckCode::Q002 => CheckKind::BadQuotesDocstring(Quote::Double),
             CheckCode::Q003 => CheckKind::AvoidQuoteEscape,
+            // flake8-annotations
+            CheckCode::ANN001 => CheckKind::MissingTypeFunctionArgument("...".to_string()),
+            CheckCode::ANN002 => CheckKind::MissingTypeArgs("...".to_string()),
+            CheckCode::ANN003 => CheckKind::MissingTypeKwargs("...".to_string()),
+            CheckCode::ANN101 => CheckKind::MissingTypeSelf("...".to_string()),
+            CheckCode::ANN102 => CheckKind::MissingTypeCls("...".to_string()),
+            CheckCode::ANN201 => CheckKind::MissingReturnTypePublicFunction("...".to_string()),
+            CheckCode::ANN202 => CheckKind::MissingReturnTypePrivateFunction("...".to_string()),
+            CheckCode::ANN204 => CheckKind::MissingReturnTypeMagicMethod("...".to_string()),
+            CheckCode::ANN205 => CheckKind::MissingReturnTypeStaticMethod("...".to_string()),
+            CheckCode::ANN206 => CheckKind::MissingReturnTypeClassMethod("...".to_string()),
+            CheckCode::ANN401 => CheckKind::DynamicallyTypedExpression("...".to_string()),
             // pyupgrade
             CheckCode::U001 => CheckKind::UselessMetaclassType,
             CheckCode::U002 => CheckKind::UnnecessaryAbspath,
@@ -523,6 +629,8 @@ impl CheckCode {
             CheckCode::U006 => CheckKind::UsePEP585Annotation("List".to_string()),
             CheckCode::U007 => CheckKind::UsePEP604Annotation,
             CheckCode::U008 => CheckKind::SuperCallWithParameters,
+            CheckCode::U009 => CheckKind::PEP3120UnnecessaryCodingComment,
+            CheckCode::U010 => CheckKind::UnnecessaryFutureImport("...".to_string()),
             // pydocstyle
             CheckCode::D100 => CheckKind::PublicModule,
             CheckCode::D101 => CheckKind::PublicClass,
@@ -600,6 +708,10 @@ impl CheckCode {
                 CheckKind::CamelcaseImportedAsAcronym("...".to_string(), "...".to_string())
             }
             CheckCode::N818 => CheckKind::ErrorSuffixOnExceptionName("...".to_string()),
+            // Ruff
+            CheckCode::RUF001 => CheckKind::AmbiguousUnicodeCharacterString('𝐁', 'B'),
+            CheckCode::RUF002 => CheckKind::AmbiguousUnicodeCharacterDocstring('𝐁', 'B'),
+            CheckCode::RUF003 => CheckKind::AmbiguousUnicodeCharacterComment('𝐁', 'B'),
             // Meta
             CheckCode::M001 => CheckKind::UnusedNOQA(None),
         }
@@ -607,22 +719,22 @@ impl CheckCode {
 
     pub fn category(&self) -> CheckCategory {
         match self {
-            CheckCode::E402 => CheckCategory::PycodestyleError,
-            CheckCode::E501 => CheckCategory::PycodestyleError,
-            CheckCode::E711 => CheckCategory::PycodestyleError,
-            CheckCode::E712 => CheckCategory::PycodestyleError,
-            CheckCode::E713 => CheckCategory::PycodestyleError,
-            CheckCode::E714 => CheckCategory::PycodestyleError,
-            CheckCode::E721 => CheckCategory::PycodestyleError,
-            CheckCode::E722 => CheckCategory::PycodestyleError,
-            CheckCode::E731 => CheckCategory::PycodestyleError,
-            CheckCode::E741 => CheckCategory::PycodestyleError,
-            CheckCode::E742 => CheckCategory::PycodestyleError,
-            CheckCode::E743 => CheckCategory::PycodestyleError,
-            CheckCode::E902 => CheckCategory::PycodestyleError,
-            CheckCode::E999 => CheckCategory::PycodestyleError,
-            CheckCode::W292 => CheckCategory::PycodestyleWarning,
-            CheckCode::W605 => CheckCategory::PycodestyleWarning,
+            CheckCode::E402 => CheckCategory::Pycodestyle,
+            CheckCode::E501 => CheckCategory::Pycodestyle,
+            CheckCode::E711 => CheckCategory::Pycodestyle,
+            CheckCode::E712 => CheckCategory::Pycodestyle,
+            CheckCode::E713 => CheckCategory::Pycodestyle,
+            CheckCode::E714 => CheckCategory::Pycodestyle,
+            CheckCode::E721 => CheckCategory::Pycodestyle,
+            CheckCode::E722 => CheckCategory::Pycodestyle,
+            CheckCode::E731 => CheckCategory::Pycodestyle,
+            CheckCode::E741 => CheckCategory::Pycodestyle,
+            CheckCode::E742 => CheckCategory::Pycodestyle,
+            CheckCode::E743 => CheckCategory::Pycodestyle,
+            CheckCode::E902 => CheckCategory::Pycodestyle,
+            CheckCode::E999 => CheckCategory::Pycodestyle,
+            CheckCode::W292 => CheckCategory::Pycodestyle,
+            CheckCode::W605 => CheckCategory::Pycodestyle,
             CheckCode::F401 => CheckCategory::Pyflakes,
             CheckCode::F402 => CheckCategory::Pyflakes,
             CheckCode::F403 => CheckCategory::Pyflakes,
@@ -655,11 +767,19 @@ impl CheckCode {
             CheckCode::A002 => CheckCategory::Flake8Builtins,
             CheckCode::A003 => CheckCategory::Flake8Builtins,
             CheckCode::B002 => CheckCategory::Flake8Bugbear,
+            CheckCode::B003 => CheckCategory::Flake8Bugbear,
+            CheckCode::B004 => CheckCategory::Flake8Bugbear,
+            CheckCode::B005 => CheckCategory::Flake8Bugbear,
+            CheckCode::B006 => CheckCategory::Flake8Bugbear,
             CheckCode::B007 => CheckCategory::Flake8Bugbear,
+            CheckCode::B008 => CheckCategory::Flake8Bugbear,
             CheckCode::B011 => CheckCategory::Flake8Bugbear,
             CheckCode::B013 => CheckCategory::Flake8Bugbear,
             CheckCode::B014 => CheckCategory::Flake8Bugbear,
+            CheckCode::B015 => CheckCategory::Flake8Bugbear,
+            CheckCode::B016 => CheckCategory::Flake8Bugbear,
             CheckCode::B017 => CheckCategory::Flake8Bugbear,
+            CheckCode::B018 => CheckCategory::Flake8Bugbear,
             CheckCode::B025 => CheckCategory::Flake8Bugbear,
             CheckCode::C400 => CheckCategory::Flake8Comprehensions,
             CheckCode::C401 => CheckCategory::Flake8Comprehensions,
@@ -683,6 +803,17 @@ impl CheckCode {
             CheckCode::Q001 => CheckCategory::Flake8Quotes,
             CheckCode::Q002 => CheckCategory::Flake8Quotes,
             CheckCode::Q003 => CheckCategory::Flake8Quotes,
+            CheckCode::ANN001 => CheckCategory::Flake8Annotations,
+            CheckCode::ANN002 => CheckCategory::Flake8Annotations,
+            CheckCode::ANN003 => CheckCategory::Flake8Annotations,
+            CheckCode::ANN101 => CheckCategory::Flake8Annotations,
+            CheckCode::ANN102 => CheckCategory::Flake8Annotations,
+            CheckCode::ANN201 => CheckCategory::Flake8Annotations,
+            CheckCode::ANN202 => CheckCategory::Flake8Annotations,
+            CheckCode::ANN204 => CheckCategory::Flake8Annotations,
+            CheckCode::ANN205 => CheckCategory::Flake8Annotations,
+            CheckCode::ANN206 => CheckCategory::Flake8Annotations,
+            CheckCode::ANN401 => CheckCategory::Flake8Annotations,
             CheckCode::U001 => CheckCategory::Pyupgrade,
             CheckCode::U002 => CheckCategory::Pyupgrade,
             CheckCode::U003 => CheckCategory::Pyupgrade,
@@ -691,6 +822,8 @@ impl CheckCode {
             CheckCode::U006 => CheckCategory::Pyupgrade,
             CheckCode::U007 => CheckCategory::Pyupgrade,
             CheckCode::U008 => CheckCategory::Pyupgrade,
+            CheckCode::U009 => CheckCategory::Pyupgrade,
+            CheckCode::U010 => CheckCategory::Pyupgrade,
             CheckCode::D100 => CheckCategory::Pydocstyle,
             CheckCode::D101 => CheckCategory::Pydocstyle,
             CheckCode::D102 => CheckCategory::Pydocstyle,
@@ -750,6 +883,9 @@ impl CheckCode {
             CheckCode::N816 => CheckCategory::PEP8Naming,
             CheckCode::N817 => CheckCategory::PEP8Naming,
             CheckCode::N818 => CheckCategory::PEP8Naming,
+            CheckCode::RUF001 => CheckCategory::Ruff,
+            CheckCode::RUF002 => CheckCategory::Ruff,
+            CheckCode::RUF003 => CheckCategory::Ruff,
             CheckCode::M001 => CheckCategory::Meta,
         }
     }
@@ -775,14 +911,14 @@ impl CheckKind {
             CheckKind::FutureFeatureNotDefined(_) => &CheckCode::F407,
             CheckKind::IOError(_) => &CheckCode::E902,
             CheckKind::IfTuple => &CheckCode::F634,
-            CheckKind::ImportShadowedByLoopVar(_, _) => &CheckCode::F402,
+            CheckKind::ImportShadowedByLoopVar(..) => &CheckCode::F402,
             CheckKind::ImportStarNotPermitted(_) => &CheckCode::F406,
-            CheckKind::ImportStarUsage(_, _) => &CheckCode::F405,
+            CheckKind::ImportStarUsage(..) => &CheckCode::F405,
             CheckKind::ImportStarUsed(_) => &CheckCode::F403,
             CheckKind::InvalidPrintSyntax => &CheckCode::F633,
             CheckKind::IsLiteral => &CheckCode::F632,
             CheckKind::LateFutureImport => &CheckCode::F404,
-            CheckKind::LineTooLong(_, _) => &CheckCode::E501,
+            CheckKind::LineTooLong(..) => &CheckCode::E501,
             CheckKind::ModuleImportNotAtTopOfFile => &CheckCode::E402,
             CheckKind::MultiValueRepeatedKeyLiteral => &CheckCode::F601,
             CheckKind::MultiValueRepeatedKeyVariable(_) => &CheckCode::F602,
@@ -793,13 +929,13 @@ impl CheckKind {
             CheckKind::ReturnOutsideFunction => &CheckCode::F706,
             CheckKind::SyntaxError(_) => &CheckCode::E999,
             CheckKind::ExpressionsInStarAssignment => &CheckCode::F621,
-            CheckKind::TrueFalseComparison(_, _) => &CheckCode::E712,
+            CheckKind::TrueFalseComparison(..) => &CheckCode::E712,
             CheckKind::TwoStarredExpressions => &CheckCode::F622,
             CheckKind::TypeComparison => &CheckCode::E721,
             CheckKind::UndefinedExport(_) => &CheckCode::F822,
             CheckKind::UndefinedLocal(_) => &CheckCode::F823,
             CheckKind::UndefinedName(_) => &CheckCode::F821,
-            CheckKind::UnusedImport(_, _) => &CheckCode::F401,
+            CheckKind::UnusedImport(..) => &CheckCode::F401,
             CheckKind::UnusedVariable(_) => &CheckCode::F841,
             CheckKind::YieldOutsideFunction => &CheckCode::F704,
             // pycodestyle warnings
@@ -811,11 +947,19 @@ impl CheckKind {
             CheckKind::BuiltinAttributeShadowing(_) => &CheckCode::A003,
             // flake8-bugbear
             CheckKind::UnaryPrefixIncrement => &CheckCode::B002,
+            CheckKind::AssignmentToOsEnviron => &CheckCode::B003,
+            CheckKind::UnreliableCallableCheck => &CheckCode::B004,
+            CheckKind::StripWithMultiCharacters => &CheckCode::B005,
+            CheckKind::MutableArgumentDefault => &CheckCode::B006,
             CheckKind::UnusedLoopControlVariable(_) => &CheckCode::B007,
+            CheckKind::FunctionCallArgumentDefault => &CheckCode::B008,
             CheckKind::DoNotAssertFalse => &CheckCode::B011,
             CheckKind::RedundantTupleInExceptionHandler(_) => &CheckCode::B013,
             CheckKind::DuplicateHandlerException(_) => &CheckCode::B014,
+            CheckKind::UselessComparison => &CheckCode::B015,
+            CheckKind::CannotRaiseLiteral => &CheckCode::B016,
             CheckKind::NoAssertRaisesException => &CheckCode::B017,
+            CheckKind::UselessExpression => &CheckCode::B018,
             CheckKind::DuplicateTryBlockException(_) => &CheckCode::B025,
             // flake8-comprehensions
             CheckKind::UnnecessaryGeneratorList => &CheckCode::C400,
@@ -842,15 +986,29 @@ impl CheckKind {
             CheckKind::BadQuotesMultilineString(_) => &CheckCode::Q001,
             CheckKind::BadQuotesDocstring(_) => &CheckCode::Q002,
             CheckKind::AvoidQuoteEscape => &CheckCode::Q003,
+            // flake8-annotations
+            CheckKind::MissingTypeFunctionArgument(_) => &CheckCode::ANN001,
+            CheckKind::MissingTypeArgs(_) => &CheckCode::ANN002,
+            CheckKind::MissingTypeKwargs(_) => &CheckCode::ANN003,
+            CheckKind::MissingTypeSelf(_) => &CheckCode::ANN101,
+            CheckKind::MissingTypeCls(_) => &CheckCode::ANN102,
+            CheckKind::MissingReturnTypePublicFunction(_) => &CheckCode::ANN201,
+            CheckKind::MissingReturnTypePrivateFunction(_) => &CheckCode::ANN202,
+            CheckKind::MissingReturnTypeMagicMethod(_) => &CheckCode::ANN204,
+            CheckKind::MissingReturnTypeStaticMethod(_) => &CheckCode::ANN205,
+            CheckKind::MissingReturnTypeClassMethod(_) => &CheckCode::ANN206,
+            CheckKind::DynamicallyTypedExpression(_) => &CheckCode::ANN401,
             // pyupgrade
             CheckKind::TypeOfPrimitive(_) => &CheckCode::U003,
             CheckKind::UnnecessaryAbspath => &CheckCode::U002,
             CheckKind::UselessMetaclassType => &CheckCode::U001,
-            CheckKind::DeprecatedUnittestAlias(_, _) => &CheckCode::U005,
+            CheckKind::DeprecatedUnittestAlias(..) => &CheckCode::U005,
             CheckKind::UsePEP585Annotation(_) => &CheckCode::U006,
             CheckKind::UsePEP604Annotation => &CheckCode::U007,
             CheckKind::UselessObjectInheritance(_) => &CheckCode::U004,
             CheckKind::SuperCallWithParameters => &CheckCode::U008,
+            CheckKind::PEP3120UnnecessaryCodingComment => &CheckCode::U009,
+            CheckKind::UnnecessaryFutureImport(_) => &CheckCode::U010,
             // pydocstyle
             CheckKind::BlankLineAfterLastSection(_) => &CheckCode::D413,
             CheckKind::BlankLineAfterSection(_) => &CheckCode::D410,
@@ -912,6 +1070,10 @@ impl CheckKind {
             CheckKind::MixedCaseVariableInGlobalScope(..) => &CheckCode::N816,
             CheckKind::CamelcaseImportedAsAcronym(..) => &CheckCode::N817,
             CheckKind::ErrorSuffixOnExceptionName(..) => &CheckCode::N818,
+            // Ruff
+            CheckKind::AmbiguousUnicodeCharacterString(..) => &CheckCode::RUF001,
+            CheckKind::AmbiguousUnicodeCharacterDocstring(..) => &CheckCode::RUF002,
+            CheckKind::AmbiguousUnicodeCharacterComment(..) => &CheckCode::RUF003,
             // Meta
             CheckKind::UnusedNOQA(_) => &CheckCode::M001,
         }
@@ -1050,11 +1212,13 @@ impl CheckKind {
                 format!("Local variable `{name}` is assigned to but never used")
             }
             CheckKind::YieldOutsideFunction => {
-                "`yield` or `yield from` statement outside of a function/method".to_string()
+                "`yield` or `yield from` statement outside of a function".to_string()
             }
             // pycodestyle warnings
             CheckKind::NoNewLineAtEndOfFile => "No newline at end of file".to_string(),
-            CheckKind::InvalidEscapeSequence(char) => format!("Invalid escape sequence: '\\{char}'"),
+            CheckKind::InvalidEscapeSequence(char) => {
+                format!("Invalid escape sequence: '\\{char}'")
+            }
             // flake8-builtins
             CheckKind::BuiltinVariableShadowing(name) => {
                 format!("Variable `{name}` is shadowing a python builtin")
@@ -1066,15 +1230,46 @@ impl CheckKind {
                 format!("Class attribute `{name}` is shadowing a python builtin")
             }
             // flake8-bugbear
-            CheckKind::UnaryPrefixIncrement => "Python does not support the unary prefix increment. Writing `++n` is equivalent to `+(+(n))`, which equals `n`. You meant `n += 1`.".to_string(),
-            CheckKind::UnusedLoopControlVariable(name) => format!("Loop control variable `{name}` not used within the loop body. If this is intended, start the name with an underscore."),
-            CheckKind::DoNotAssertFalse => {
-                "Do not `assert False` (`python -O` removes these calls), raise `AssertionError()`"
-                    .to_string()
+            CheckKind::UnaryPrefixIncrement => "Python does not support the unary prefix \
+                                                increment. Writing `++n` is equivalent to \
+                                                `+(+(n))`, which equals `n`. You meant `n += 1`."
+                .to_string(),
+            CheckKind::AssignmentToOsEnviron => {
+                "Assigning to `os.environ` doesn't clear the environment.".to_string()
             }
+            CheckKind::UnreliableCallableCheck => " Using `hasattr(x, '__call__')` to test if x \
+                                                   is callable is unreliable. Use `callable(x)` \
+                                                   for consistent results."
+                .to_string(),
+            CheckKind::StripWithMultiCharacters => "Using `.strip()` with multi-character strings \
+                                                    is misleading the reader."
+                .to_string(),
+            CheckKind::MutableArgumentDefault => {
+                "Do not use mutable data structures for argument defaults.".to_string()
+            }
+            CheckKind::UnusedLoopControlVariable(name) => format!(
+                "Loop control variable `{name}` not used within the loop body. If this is \
+                 intended, start the name with an underscore."
+            ),
+            CheckKind::FunctionCallArgumentDefault => {
+                "Do not perform function calls in argument defaults.".to_string()
+            }
+            CheckKind::DoNotAssertFalse => "Do not `assert False` (`python -O` removes these \
+                                            calls), raise `AssertionError()`"
+                .to_string(),
             CheckKind::RedundantTupleInExceptionHandler(name) => {
-                format!("A length-one tuple literal is redundant. Write `except {name}:` instead of `except ({name},):`.")
+                format!(
+                    "A length-one tuple literal is redundant. Write `except {name}:` instead of \
+                     `except ({name},):`."
+                )
             }
+            CheckKind::UselessComparison => "Pointless comparison. This comparison does nothing \
+                                             but waste CPU instructions. Either prepend `assert` \
+                                             or remove it."
+                .to_string(),
+            CheckKind::CannotRaiseLiteral => "Cannot raise a literal. Did you intend to return it \
+                                              or raise an Exception?"
+                .to_string(),
             CheckKind::DuplicateHandlerException(names) => {
                 if names.len() == 1 {
                     let name = &names[0];
@@ -1085,8 +1280,15 @@ impl CheckKind {
                 }
             }
             CheckKind::NoAssertRaisesException => {
-                "`assertRaises(Exception):` should be considered evil. It can lead to your test passing even if the code being tested is never executed due to a typo. Either assert for a more specific exception (builtin or custom), use `assertRaisesRegex`, or use the context manager form of `assertRaises`.".to_string()
-           }
+                "`assertRaises(Exception):` should be considered evil. It can lead to your test \
+                 passing even if the code being tested is never executed due to a typo. Either \
+                 assert for a more specific exception (builtin or custom), use \
+                 `assertRaisesRegex`, or use the context manager form of `assertRaises`."
+                    .to_string()
+            }
+            CheckKind::UselessExpression => {
+                "Found useless expression. Either assign it to a variable or remove it.".to_string()
+            }
             CheckKind::DuplicateTryBlockException(name) => {
                 format!("try-except block with duplicate exception `{name}`")
             }
@@ -1118,22 +1320,26 @@ impl CheckKind {
             CheckKind::UnnecessaryLiteralWithinTupleCall(literal) => {
                 if literal == "list" {
                     format!(
-                        "Unnecessary `{literal}` literal passed to `tuple()` (rewrite as a `tuple` literal)"
+                        "Unnecessary `{literal}` literal passed to `tuple()` (rewrite as a \
+                         `tuple` literal)"
                     )
                 } else {
                     format!(
-                        "Unnecessary `{literal}` literal passed to `tuple()` (remove the outer call to `tuple()`)"
+                        "Unnecessary `{literal}` literal passed to `tuple()` (remove the outer \
+                         call to `tuple()`)"
                     )
                 }
             }
             CheckKind::UnnecessaryLiteralWithinListCall(literal) => {
                 if literal == "list" {
                     format!(
-                        "Unnecessary `{literal}` literal passed to `list()` (remove the outer call to `list()`)"
+                        "Unnecessary `{literal}` literal passed to `list()` (remove the outer \
+                         call to `list()`)"
                     )
                 } else {
                     format!(
-                        "Unnecessary `{literal}` literal passed to `list()` (rewrite as a `list` literal)"
+                        "Unnecessary `{literal}` literal passed to `list()` (rewrite as a `list` \
+                         literal)"
                     )
                 }
             }
@@ -1150,7 +1356,7 @@ impl CheckKind {
                 format!("Unnecessary subscript reversal of iterable within `{func}()`")
             }
             CheckKind::UnnecessaryComprehension(obj_type) => {
-                format!(" Unnecessary `{obj_type}` comprehension (rewrite using `{obj_type}()`)")
+                format!("Unnecessary `{obj_type}` comprehension (rewrite using `{obj_type}()`)")
             }
             CheckKind::UnnecessaryMap(obj_type) => {
                 if obj_type == "generator" {
@@ -1163,25 +1369,61 @@ impl CheckKind {
             CheckKind::PrintFound => "`print` found".to_string(),
             CheckKind::PPrintFound => "`pprint` found".to_string(),
             // flake8-quotes
-            CheckKind::BadQuotesInlineString(quote) => {
-                match quote {
-                    Quote::Single => "Double quotes found but single quotes preferred".to_string(),
-                    Quote::Double => "Single quotes found but double quotes preferred".to_string(),
+            CheckKind::BadQuotesInlineString(quote) => match quote {
+                Quote::Single => "Double quotes found but single quotes preferred".to_string(),
+                Quote::Double => "Single quotes found but double quotes preferred".to_string(),
+            },
+            CheckKind::BadQuotesMultilineString(quote) => match quote {
+                Quote::Single => {
+                    "Double quote multiline found but single quotes preferred".to_string()
+                }
+                Quote::Double => {
+                    "Single quote multiline found but double quotes preferred".to_string()
                 }
             },
-            CheckKind::BadQuotesMultilineString(quote) => {
-                match quote {
-                    Quote::Single => "Double quote multiline found but single quotes preferred".to_string(),
-                    Quote::Double => "Single quote multiline found but double quotes preferred".to_string(),
+            CheckKind::BadQuotesDocstring(quote) => match quote {
+                Quote::Single => {
+                    "Double quote docstring found but single quotes preferred".to_string()
+                }
+                Quote::Double => {
+                    "Single quote docstring found but double quotes preferred".to_string()
                 }
             },
-            CheckKind::BadQuotesDocstring(quote) => {
-                match quote {
-                    Quote::Single => "Double quote docstring found but single quotes preferred".to_string(),
-                    Quote::Double => "Single quote docstring found but double quotes preferred".to_string(),
-                }
-            },
-            CheckKind::AvoidQuoteEscape => "Change outer quotes to avoid escaping inner quotes".to_string(),
+            CheckKind::AvoidQuoteEscape => {
+                "Change outer quotes to avoid escaping inner quotes".to_string()
+            }
+            // flake8-annotations
+            CheckKind::MissingTypeFunctionArgument(name) => {
+                format!("Missing type annotation for function argument `{name}`")
+            }
+            CheckKind::MissingTypeArgs(name) => format!("Missing type annotation for `*{name}`"),
+            CheckKind::MissingTypeKwargs(name) => {
+                format!("Missing type annotation for `**{name}`")
+            }
+            CheckKind::MissingTypeSelf(name) => {
+                format!("Missing type annotation for `{name}` in method")
+            }
+            CheckKind::MissingTypeCls(name) => {
+                format!("Missing type annotation for `{name}` in classmethod")
+            }
+            CheckKind::MissingReturnTypePublicFunction(name) => {
+                format!("Missing return type annotation for public function `{name}`")
+            }
+            CheckKind::MissingReturnTypePrivateFunction(name) => {
+                format!("Missing return type annotation for private function `{name}`")
+            }
+            CheckKind::MissingReturnTypeMagicMethod(name) => {
+                format!("Missing return type annotation for magic method `{name}`")
+            }
+            CheckKind::MissingReturnTypeStaticMethod(name) => {
+                format!("Missing return type annotation for staticmethod `{name}`")
+            }
+            CheckKind::MissingReturnTypeClassMethod(name) => {
+                format!("Missing return type annotation for classmethod `{name}`")
+            }
+            CheckKind::DynamicallyTypedExpression(name) => {
+                format!("Dynamically typed expressions (typing.Any) are disallowed in `{name}`")
+            }
             // pyupgrade
             CheckKind::TypeOfPrimitive(primitive) => {
                 format!("Use `{}` instead of `type(...)`", primitive.builtin())
@@ -1191,7 +1433,7 @@ impl CheckKind {
             }
             CheckKind::UselessMetaclassType => "`__metaclass__ = type` is implied".to_string(),
             CheckKind::DeprecatedUnittestAlias(alias, target) => {
-                format!("`{}` is deprecated, use `{}` instead", alias, target)
+                format!("`{alias}` is deprecated, use `{target}` instead")
             }
             CheckKind::UselessObjectInheritance(name) => {
                 format!("Class `{name}` inherits from object")
@@ -1207,6 +1449,9 @@ impl CheckKind {
             CheckKind::SuperCallWithParameters => {
                 "Use `super()` instead of `super(__class__, self)`".to_string()
             }
+            CheckKind::UnnecessaryFutureImport(name) => {
+                format!("Unnessary __future__ import `{name}` for target Python version")
+            }
             // pydocstyle
             CheckKind::FitsOnOneLine => "One-line docstring should fit on one line".to_string(),
             CheckKind::BlankLineAfterSummary => {
@@ -1220,10 +1465,9 @@ impl CheckKind {
             }
             CheckKind::EndsInPeriod => "First line should end with a period".to_string(),
             CheckKind::NonEmpty => "Docstring is empty".to_string(),
-            CheckKind::EndsInPunctuation => {
-                "First line should end with a period, question mark, or exclamation point"
-                    .to_string()
-            }
+            CheckKind::EndsInPunctuation => "First line should end with a period, question mark, \
+                                             or exclamation point"
+                .to_string(),
             CheckKind::FirstLineCapitalized => {
                 "First word of the first line should be properly capitalized".to_string()
             }
@@ -1261,10 +1505,10 @@ impl CheckKind {
             CheckKind::PublicNestedClass => "Missing docstring in public nested class".to_string(),
             CheckKind::PublicInit => "Missing docstring in `__init__`".to_string(),
             CheckKind::NoThisPrefix => {
-                "First word of the docstring should not be `This`".to_string()
+                "First word of the docstring should not be 'This'".to_string()
             }
             CheckKind::SkipDocstring => {
-                "Function decorated with @overload shouldn't contain a docstring".to_string()
+                "Function decorated with `@overload` shouldn't contain a docstring".to_string()
             }
             CheckKind::CapitalizeSectionName(name) => {
                 format!("Section name should be properly capitalized (\"{name}\")")
@@ -1285,7 +1529,10 @@ impl CheckKind {
                 format!("Missing dashed underline after section (\"{name}\")")
             }
             CheckKind::SectionUnderlineAfterName(name) => {
-                format!("Section underline should be in the line following the section's name (\"{name}\")")
+                format!(
+                    "Section underline should be in the line following the section's name \
+                     (\"{name}\")"
+                )
             }
             CheckKind::SectionUnderlineMatchesSectionLength(name) => {
                 format!("Section underline should match the length of its name (\"{name}\")")
@@ -1365,6 +1612,28 @@ impl CheckKind {
             CheckKind::ErrorSuffixOnExceptionName(name) => {
                 format!("Exception name `{name}` should be named with an Error suffix")
             }
+            CheckKind::PEP3120UnnecessaryCodingComment => {
+                "utf-8 encoding declaration is unnecessary".to_string()
+            }
+            // Ruff
+            CheckKind::AmbiguousUnicodeCharacterString(confusable, representant) => {
+                format!(
+                    "String contains ambiguous unicode character '{confusable}' (did you mean \
+                     '{representant}'?)"
+                )
+            }
+            CheckKind::AmbiguousUnicodeCharacterDocstring(confusable, representant) => {
+                format!(
+                    "Docstring contains ambiguous unicode character '{confusable}' (did you mean \
+                     '{representant}'?)"
+                )
+            }
+            CheckKind::AmbiguousUnicodeCharacterComment(confusable, representant) => {
+                format!(
+                    "Comment contains ambiguous unicode character '{confusable}' (did you mean \
+                     '{representant}'?)"
+                )
+            }
             // Meta
             CheckKind::UnusedNOQA(codes) => match codes {
                 None => "Unused `noqa` directive".to_string(),
@@ -1385,7 +1654,8 @@ impl CheckKind {
         }
     }
 
-    /// The summary text for the check. Typically a truncated form of the body text.
+    /// The summary text for the check. Typically a truncated form of the body
+    /// text.
     pub fn summary(&self) -> String {
         match self {
             CheckKind::UnaryPrefixIncrement => {
@@ -1405,7 +1675,9 @@ impl CheckKind {
     pub fn fixable(&self) -> bool {
         matches!(
             self,
-            CheckKind::BlankLineAfterLastSection(_)
+            CheckKind::AmbiguousUnicodeCharacterString(_, _)
+                | CheckKind::AmbiguousUnicodeCharacterDocstring(_, _)
+                | CheckKind::BlankLineAfterLastSection(_)
                 | CheckKind::BlankLineAfterSection(_)
                 | CheckKind::BlankLineAfterSummary
                 | CheckKind::BlankLineBeforeSection(_)
@@ -1427,6 +1699,7 @@ impl CheckKind {
                 | CheckKind::OneBlankLineBeforeClass(_)
                 | CheckKind::PPrintFound
                 | CheckKind::PrintFound
+                | CheckKind::RaiseNotImplemented
                 | CheckKind::SectionNameEndsInColon(_)
                 | CheckKind::SectionNotOverIndented(_)
                 | CheckKind::SectionUnderlineAfterName(_)
@@ -1435,6 +1708,18 @@ impl CheckKind {
                 | CheckKind::SuperCallWithParameters
                 | CheckKind::TypeOfPrimitive(_)
                 | CheckKind::UnnecessaryAbspath
+                | CheckKind::UnnecessaryCollectionCall(_)
+                | CheckKind::UnnecessaryComprehension(_)
+                | CheckKind::UnnecessaryGeneratorDict
+                | CheckKind::UnnecessaryGeneratorList
+                | CheckKind::UnnecessaryGeneratorSet
+                | CheckKind::UnnecessaryListCall
+                | CheckKind::UnnecessaryListComprehensionSet
+                | CheckKind::UnnecessaryListComprehensionDict
+                | CheckKind::UnnecessaryLiteralDict(_)
+                | CheckKind::UnnecessaryLiteralSet(_)
+                | CheckKind::UnnecessaryLiteralWithinListCall(_)
+                | CheckKind::UnnecessaryLiteralWithinTupleCall(_)
                 | CheckKind::UnusedImport(_, false)
                 | CheckKind::UnusedLoopControlVariable(_)
                 | CheckKind::UnusedNOQA(_)
@@ -1442,6 +1727,8 @@ impl CheckKind {
                 | CheckKind::UsePEP604Annotation
                 | CheckKind::UselessMetaclassType
                 | CheckKind::UselessObjectInheritance(_)
+                | CheckKind::PEP3120UnnecessaryCodingComment
+                | CheckKind::IsLiteral
         )
     }
 }

src/checks_gen.rs

@@ -5,7 +5,7 @@ use strum_macros::EnumString;
 
 use crate::checks::CheckCode;
 
-#[derive(EnumString, Debug, PartialEq, Eq, Clone, Serialize, Deserialize)]
+#[derive(EnumString, Debug, PartialEq, Eq, PartialOrd, Ord, Clone, Serialize, Deserialize)]
 pub enum CheckCodePrefix {
     A,
     A0,
@@ -13,16 +13,44 @@ pub enum CheckCodePrefix {
     A001,
     A002,
     A003,
+    ANN,
+    ANN0,
+    ANN00,
+    ANN001,
+    ANN002,
+    ANN003,
+    ANN1,
+    ANN10,
+    ANN101,
+    ANN102,
+    ANN2,
+    ANN20,
+    ANN201,
+    ANN202,
+    ANN204,
+    ANN205,
+    ANN206,
+    ANN4,
+    ANN40,
+    ANN401,
     B,
     B0,
     B00,
     B002,
+    B003,
+    B004,
+    B005,
+    B006,
     B007,
+    B008,
     B01,
     B011,
     B013,
     B014,
+    B015,
+    B016,
     B017,
+    B018,
     B02,
     B025,
     C,
@@ -203,6 +231,12 @@ pub enum CheckCodePrefix {
     Q001,
     Q002,
     Q003,
+    RUF,
+    RUF0,
+    RUF00,
+    RUF001,
+    RUF002,
+    RUF003,
     T,
     T2,
     T20,
@@ -219,6 +253,9 @@ pub enum CheckCodePrefix {
     U006,
     U007,
     U008,
+    U009,
+    U01,
+    U010,
     W,
     W2,
     W29,
@@ -245,37 +282,116 @@ impl CheckCodePrefix {
             CheckCodePrefix::A001 => vec![CheckCode::A001],
             CheckCodePrefix::A002 => vec![CheckCode::A002],
             CheckCodePrefix::A003 => vec![CheckCode::A003],
+            CheckCodePrefix::ANN => vec![
+                CheckCode::ANN001,
+                CheckCode::ANN002,
+                CheckCode::ANN003,
+                CheckCode::ANN101,
+                CheckCode::ANN102,
+                CheckCode::ANN201,
+                CheckCode::ANN202,
+                CheckCode::ANN204,
+                CheckCode::ANN205,
+                CheckCode::ANN206,
+                CheckCode::ANN401,
+            ],
+            CheckCodePrefix::ANN0 => vec![CheckCode::ANN001, CheckCode::ANN002, CheckCode::ANN003],
+            CheckCodePrefix::ANN00 => vec![CheckCode::ANN001, CheckCode::ANN002, CheckCode::ANN003],
+            CheckCodePrefix::ANN001 => vec![CheckCode::ANN001],
+            CheckCodePrefix::ANN002 => vec![CheckCode::ANN002],
+            CheckCodePrefix::ANN003 => vec![CheckCode::ANN003],
+            CheckCodePrefix::ANN1 => vec![CheckCode::ANN101, CheckCode::ANN102],
+            CheckCodePrefix::ANN10 => vec![CheckCode::ANN101, CheckCode::ANN102],
+            CheckCodePrefix::ANN101 => vec![CheckCode::ANN101],
+            CheckCodePrefix::ANN102 => vec![CheckCode::ANN102],
+            CheckCodePrefix::ANN2 => vec![
+                CheckCode::ANN201,
+                CheckCode::ANN202,
+                CheckCode::ANN204,
+                CheckCode::ANN205,
+                CheckCode::ANN206,
+            ],
+            CheckCodePrefix::ANN20 => vec![
+                CheckCode::ANN201,
+                CheckCode::ANN202,
+                CheckCode::ANN204,
+                CheckCode::ANN205,
+                CheckCode::ANN206,
+            ],
+            CheckCodePrefix::ANN201 => vec![CheckCode::ANN201],
+            CheckCodePrefix::ANN202 => vec![CheckCode::ANN202],
+            CheckCodePrefix::ANN204 => vec![CheckCode::ANN204],
+            CheckCodePrefix::ANN205 => vec![CheckCode::ANN205],
+            CheckCodePrefix::ANN206 => vec![CheckCode::ANN206],
+            CheckCodePrefix::ANN4 => vec![CheckCode::ANN401],
+            CheckCodePrefix::ANN40 => vec![CheckCode::ANN401],
+            CheckCodePrefix::ANN401 => vec![CheckCode::ANN401],
             CheckCodePrefix::B => vec![
                 CheckCode::B002,
+                CheckCode::B003,
+                CheckCode::B004,
+                CheckCode::B005,
+                CheckCode::B006,
                 CheckCode::B007,
+                CheckCode::B008,
                 CheckCode::B011,
                 CheckCode::B013,
                 CheckCode::B014,
+                CheckCode::B015,
+                CheckCode::B016,
                 CheckCode::B017,
+                CheckCode::B018,
                 CheckCode::B025,
             ],
             CheckCodePrefix::B0 => vec![
                 CheckCode::B002,
+                CheckCode::B003,
+                CheckCode::B004,
+                CheckCode::B005,
+                CheckCode::B006,
                 CheckCode::B007,
+                CheckCode::B008,
                 CheckCode::B011,
                 CheckCode::B013,
                 CheckCode::B014,
+                CheckCode::B015,
+                CheckCode::B016,
                 CheckCode::B017,
+                CheckCode::B018,
                 CheckCode::B025,
             ],
-            CheckCodePrefix::B00 => vec![CheckCode::B002, CheckCode::B007],
+            CheckCodePrefix::B00 => vec![
+                CheckCode::B002,
+                CheckCode::B003,
+                CheckCode::B004,
+                CheckCode::B005,
+                CheckCode::B006,
+                CheckCode::B007,
+                CheckCode::B008,
+            ],
             CheckCodePrefix::B002 => vec![CheckCode::B002],
+            CheckCodePrefix::B003 => vec![CheckCode::B003],
+            CheckCodePrefix::B004 => vec![CheckCode::B004],
+            CheckCodePrefix::B005 => vec![CheckCode::B005],
+            CheckCodePrefix::B006 => vec![CheckCode::B006],
             CheckCodePrefix::B007 => vec![CheckCode::B007],
+            CheckCodePrefix::B008 => vec![CheckCode::B008],
             CheckCodePrefix::B01 => vec![
                 CheckCode::B011,
                 CheckCode::B013,
                 CheckCode::B014,
+                CheckCode::B015,
+                CheckCode::B016,
                 CheckCode::B017,
+                CheckCode::B018,
             ],
             CheckCodePrefix::B011 => vec![CheckCode::B011],
             CheckCodePrefix::B013 => vec![CheckCode::B013],
             CheckCodePrefix::B014 => vec![CheckCode::B014],
+            CheckCodePrefix::B015 => vec![CheckCode::B015],
+            CheckCodePrefix::B016 => vec![CheckCode::B016],
             CheckCodePrefix::B017 => vec![CheckCode::B017],
+            CheckCodePrefix::B018 => vec![CheckCode::B018],
             CheckCodePrefix::B02 => vec![CheckCode::B025],
             CheckCodePrefix::B025 => vec![CheckCode::B025],
             CheckCodePrefix::C => vec![
@@ -820,6 +936,12 @@ impl CheckCodePrefix {
             CheckCodePrefix::Q001 => vec![CheckCode::Q001],
             CheckCodePrefix::Q002 => vec![CheckCode::Q002],
             CheckCodePrefix::Q003 => vec![CheckCode::Q003],
+            CheckCodePrefix::RUF => vec![CheckCode::RUF001, CheckCode::RUF002, CheckCode::RUF003],
+            CheckCodePrefix::RUF0 => vec![CheckCode::RUF001, CheckCode::RUF002, CheckCode::RUF003],
+            CheckCodePrefix::RUF00 => vec![CheckCode::RUF001, CheckCode::RUF002, CheckCode::RUF003],
+            CheckCodePrefix::RUF001 => vec![CheckCode::RUF001],
+            CheckCodePrefix::RUF002 => vec![CheckCode::RUF002],
+            CheckCodePrefix::RUF003 => vec![CheckCode::RUF003],
             CheckCodePrefix::T => vec![CheckCode::T201, CheckCode::T203],
             CheckCodePrefix::T2 => vec![CheckCode::T201, CheckCode::T203],
             CheckCodePrefix::T20 => vec![CheckCode::T201, CheckCode::T203],
@@ -834,6 +956,8 @@ impl CheckCodePrefix {
                 CheckCode::U006,
                 CheckCode::U007,
                 CheckCode::U008,
+                CheckCode::U009,
+                CheckCode::U010,
             ],
             CheckCodePrefix::U0 => vec![
                 CheckCode::U001,
@@ -844,6 +968,8 @@ impl CheckCodePrefix {
                 CheckCode::U006,
                 CheckCode::U007,
                 CheckCode::U008,
+                CheckCode::U009,
+                CheckCode::U010,
             ],
             CheckCodePrefix::U00 => vec![
                 CheckCode::U001,
@@ -854,6 +980,7 @@ impl CheckCodePrefix {
                 CheckCode::U006,
                 CheckCode::U007,
                 CheckCode::U008,
+                CheckCode::U009,
             ],
             CheckCodePrefix::U001 => vec![CheckCode::U001],
             CheckCodePrefix::U002 => vec![CheckCode::U002],
@@ -863,6 +990,9 @@ impl CheckCodePrefix {
             CheckCodePrefix::U006 => vec![CheckCode::U006],
             CheckCodePrefix::U007 => vec![CheckCode::U007],
             CheckCodePrefix::U008 => vec![CheckCode::U008],
+            CheckCodePrefix::U009 => vec![CheckCode::U009],
+            CheckCodePrefix::U01 => vec![CheckCode::U010],
+            CheckCodePrefix::U010 => vec![CheckCode::U010],
             CheckCodePrefix::W => vec![CheckCode::W292, CheckCode::W605],
             CheckCodePrefix::W2 => vec![CheckCode::W292],
             CheckCodePrefix::W29 => vec![CheckCode::W292],
@@ -883,16 +1013,44 @@ impl CheckCodePrefix {
             CheckCodePrefix::A001 => PrefixSpecificity::Explicit,
             CheckCodePrefix::A002 => PrefixSpecificity::Explicit,
             CheckCodePrefix::A003 => PrefixSpecificity::Explicit,
+            CheckCodePrefix::ANN => PrefixSpecificity::Category,
+            CheckCodePrefix::ANN0 => PrefixSpecificity::Hundreds,
+            CheckCodePrefix::ANN00 => PrefixSpecificity::Tens,
+            CheckCodePrefix::ANN001 => PrefixSpecificity::Explicit,
+            CheckCodePrefix::ANN002 => PrefixSpecificity::Explicit,
+            CheckCodePrefix::ANN003 => PrefixSpecificity::Explicit,
+            CheckCodePrefix::ANN1 => PrefixSpecificity::Hundreds,
+            CheckCodePrefix::ANN10 => PrefixSpecificity::Tens,
+            CheckCodePrefix::ANN101 => PrefixSpecificity::Explicit,
+            CheckCodePrefix::ANN102 => PrefixSpecificity::Explicit,
+            CheckCodePrefix::ANN2 => PrefixSpecificity::Hundreds,
+            CheckCodePrefix::ANN20 => PrefixSpecificity::Tens,
+            CheckCodePrefix::ANN201 => PrefixSpecificity::Explicit,
+            CheckCodePrefix::ANN202 => PrefixSpecificity::Explicit,
+            CheckCodePrefix::ANN204 => PrefixSpecificity::Explicit,
+            CheckCodePrefix::ANN205 => PrefixSpecificity::Explicit,
+            CheckCodePrefix::ANN206 => PrefixSpecificity::Explicit,
+            CheckCodePrefix::ANN4 => PrefixSpecificity::Hundreds,
+            CheckCodePrefix::ANN40 => PrefixSpecificity::Tens,
+            CheckCodePrefix::ANN401 => PrefixSpecificity::Explicit,
             CheckCodePrefix::B => PrefixSpecificity::Category,
             CheckCodePrefix::B0 => PrefixSpecificity::Hundreds,
             CheckCodePrefix::B00 => PrefixSpecificity::Tens,
             CheckCodePrefix::B002 => PrefixSpecificity::Explicit,
+            CheckCodePrefix::B003 => PrefixSpecificity::Explicit,
+            CheckCodePrefix::B004 => PrefixSpecificity::Explicit,
+            CheckCodePrefix::B005 => PrefixSpecificity::Explicit,
+            CheckCodePrefix::B006 => PrefixSpecificity::Explicit,
             CheckCodePrefix::B007 => PrefixSpecificity::Explicit,
+            CheckCodePrefix::B008 => PrefixSpecificity::Explicit,
             CheckCodePrefix::B01 => PrefixSpecificity::Tens,
             CheckCodePrefix::B011 => PrefixSpecificity::Explicit,
             CheckCodePrefix::B013 => PrefixSpecificity::Explicit,
             CheckCodePrefix::B014 => PrefixSpecificity::Explicit,
+            CheckCodePrefix::B015 => PrefixSpecificity::Explicit,
+            CheckCodePrefix::B016 => PrefixSpecificity::Explicit,
             CheckCodePrefix::B017 => PrefixSpecificity::Explicit,
+            CheckCodePrefix::B018 => PrefixSpecificity::Explicit,
             CheckCodePrefix::B02 => PrefixSpecificity::Tens,
             CheckCodePrefix::B025 => PrefixSpecificity::Explicit,
             CheckCodePrefix::C => PrefixSpecificity::Category,
@@ -1073,6 +1231,12 @@ impl CheckCodePrefix {
             CheckCodePrefix::Q001 => PrefixSpecificity::Explicit,
             CheckCodePrefix::Q002 => PrefixSpecificity::Explicit,
             CheckCodePrefix::Q003 => PrefixSpecificity::Explicit,
+            CheckCodePrefix::RUF => PrefixSpecificity::Category,
+            CheckCodePrefix::RUF0 => PrefixSpecificity::Hundreds,
+            CheckCodePrefix::RUF00 => PrefixSpecificity::Tens,
+            CheckCodePrefix::RUF001 => PrefixSpecificity::Explicit,
+            CheckCodePrefix::RUF002 => PrefixSpecificity::Explicit,
+            CheckCodePrefix::RUF003 => PrefixSpecificity::Explicit,
             CheckCodePrefix::T => PrefixSpecificity::Category,
             CheckCodePrefix::T2 => PrefixSpecificity::Hundreds,
             CheckCodePrefix::T20 => PrefixSpecificity::Tens,
@@ -1089,6 +1253,9 @@ impl CheckCodePrefix {
             CheckCodePrefix::U006 => PrefixSpecificity::Explicit,
             CheckCodePrefix::U007 => PrefixSpecificity::Explicit,
             CheckCodePrefix::U008 => PrefixSpecificity::Explicit,
+            CheckCodePrefix::U009 => PrefixSpecificity::Explicit,
+            CheckCodePrefix::U01 => PrefixSpecificity::Tens,
+            CheckCodePrefix::U010 => PrefixSpecificity::Explicit,
             CheckCodePrefix::W => PrefixSpecificity::Category,
             CheckCodePrefix::W2 => PrefixSpecificity::Hundreds,
             CheckCodePrefix::W29 => PrefixSpecificity::Tens,

src/cli.rs

@@ -1,3 +1,4 @@
+use std::collections::BTreeMap;
 use std::fmt;
 use std::path::PathBuf;
 
@@ -6,10 +7,10 @@ use log::warn;
 use regex::Regex;
 
 use crate::checks_gen::CheckCodePrefix;
+use crate::logging::LogLevel;
 use crate::printer::SerializationFormat;
 use crate::settings::configuration::Configuration;
-use crate::settings::types::PythonVersion;
-use crate::settings::types::StrCheckCodePair;
+use crate::settings::types::{PatternPrefixPair, PerFileIgnore, PythonVersion};
 
 #[derive(Debug, Parser)]
 #[command(author, about = "ruff: An extremely fast Python linter.")]
@@ -26,7 +27,8 @@ pub struct Cli {
     /// Only log errors.
     #[arg(short, long, group = "verbosity")]
     pub quiet: bool,
-    /// Disable all logging (but still exit with status code "1" upon detecting errors).
+    /// Disable all logging (but still exit with status code "1" upon detecting
+    /// errors).
     #[arg(short, long, group = "verbosity")]
     pub silent: bool,
     /// Exit with status code "0", even upon detecting errors.
@@ -36,32 +38,37 @@ pub struct Cli {
     #[arg(short, long)]
     pub watch: bool,
     /// Attempt to automatically fix lint errors.
-    #[arg(short, long)]
-    pub fix: bool,
+    #[arg(long, overrides_with("no_fix"))]
+    fix: bool,
+    #[clap(long, overrides_with("fix"), hide = true)]
+    no_fix: bool,
     /// Disable cache reads.
     #[arg(short, long)]
     pub no_cache: bool,
     /// List of error codes to enable.
     #[arg(long, value_delimiter = ',')]
     pub select: Vec<CheckCodePrefix>,
-    /// Like --select, but adds additional error codes on top of the selected ones.
+    /// Like --select, but adds additional error codes on top of the selected
+    /// ones.
     #[arg(long, value_delimiter = ',')]
     pub extend_select: Vec<CheckCodePrefix>,
     /// List of error codes to ignore.
     #[arg(long, value_delimiter = ',')]
     pub ignore: Vec<CheckCodePrefix>,
-    /// Like --ignore, but adds additional error codes on top of the ignored ones.
+    /// Like --ignore, but adds additional error codes on top of the ignored
+    /// ones.
     #[arg(long, value_delimiter = ',')]
     pub extend_ignore: Vec<CheckCodePrefix>,
     /// List of paths, used to exclude files and/or directories from checks.
     #[arg(long, value_delimiter = ',')]
     pub exclude: Vec<String>,
-    /// Like --exclude, but adds additional files and directories on top of the excluded ones.
+    /// Like --exclude, but adds additional files and directories on top of the
+    /// excluded ones.
     #[arg(long, value_delimiter = ',')]
     pub extend_exclude: Vec<String>,
     /// List of mappings from file pattern to code to exclude
     #[arg(long, value_delimiter = ',')]
-    pub per_file_ignores: Vec<StrCheckCodePair>,
+    pub per_file_ignores: Vec<PatternPrefixPair>,
     /// Output serialization format for error messages.
     #[arg(long, value_enum, default_value_t=SerializationFormat::Text)]
     pub format: SerializationFormat,
@@ -89,6 +96,35 @@ pub struct Cli {
     pub stdin_filename: Option<String>,
 }
 
+impl Cli {
+    // See: https://github.com/clap-rs/clap/issues/3146
+    pub fn fix(&self) -> Option<bool> {
+        resolve_bool_arg(self.fix, self.no_fix)
+    }
+}
+
+fn resolve_bool_arg(yes: bool, no: bool) -> Option<bool> {
+    match (yes, no) {
+        (true, false) => Some(true),
+        (false, true) => Some(false),
+        (false, false) => None,
+        (..) => unreachable!("Clap should make this impossible"),
+    }
+}
+
+/// Map the CLI settings to a `LogLevel`.
+pub fn extract_log_level(cli: &Cli) -> LogLevel {
+    if cli.silent {
+        LogLevel::Silent
+    } else if cli.quiet {
+        LogLevel::Quiet
+    } else if cli.verbose {
+        LogLevel::Verbose
+    } else {
+        LogLevel::Default
+    }
+}
+
 pub enum Warnable {
     Select,
     ExtendSelect,
@@ -138,8 +174,29 @@ pub fn warn_on(
                     path.to_string_lossy()
                 )
             } else {
-                warn!("{code:?} was passed to {flag}, but ignored by the default `extend_ignore` field")
+                warn!(
+                    "{code:?} was passed to {flag}, but ignored by the default `extend_ignore` \
+                     field"
+                )
             }
         }
     }
 }
+
+/// Convert a list of `PatternPrefixPair` structs to `PerFileIgnore`.
+pub fn collect_per_file_ignores(
+    pairs: Vec<PatternPrefixPair>,
+    project_root: &Option<PathBuf>,
+) -> Vec<PerFileIgnore> {
+    let mut per_file_ignores: BTreeMap<String, Vec<CheckCodePrefix>> = BTreeMap::new();
+    for pair in pairs {
+        per_file_ignores
+            .entry(pair.pattern)
+            .or_insert_with(Vec::new)
+            .push(pair.prefix);
+    }
+    per_file_ignores
+        .iter()
+        .map(|(pattern, prefixes)| PerFileIgnore::new(pattern, prefixes, project_root))
+        .collect()
+}

src/cst/matchers.rs

@@ -0,0 +1,21 @@
+use anyhow::Result;
+use libcst_native::{Expr, Module, SmallStatement, Statement};
+
+pub fn match_module(module_text: &str) -> Result<Module> {
+    match libcst_native::parse_module(module_text, None) {
+        Ok(module) => Ok(module),
+        Err(_) => Err(anyhow::anyhow!("Failed to extract CST from source.")),
+    }
+}
+
+pub fn match_expr<'a, 'b>(module: &'a mut Module<'b>) -> Result<&'a mut Expr<'b>> {
+    if let Some(Statement::Simple(expr)) = module.body.first_mut() {
+        if let Some(SmallStatement::Expr(expr)) = expr.body.first_mut() {
+            Ok(expr)
+        } else {
+            Err(anyhow::anyhow!("Expected node to be: SmallStatement::Expr"))
+        }
+    } else {
+        Err(anyhow::anyhow!("Expected node to be: Statement::Simple"))
+    }
+}

src/cst/mod.rs

@@ -1 +1,2 @@
 pub mod helpers;
+pub mod matchers;

src/docstrings/helpers.rs

@@ -25,12 +25,15 @@ pub fn leading_space(line: &str) -> String {
 }
 
 /// Extract the leading indentation from a docstring.
-pub fn indentation<'a>(checker: &'a Checker, docstring: &Expr) -> &'a str {
+pub fn indentation<'a>(checker: &'a Checker, docstring: &Expr) -> String {
     let range = Range::from_located(docstring);
-    checker.get_locator().slice_source_code_range(&Range {
-        location: Location::new(range.location.row(), 1),
-        end_location: Location::new(range.location.row(), range.location.column()),
-    })
+    checker
+        .locator
+        .slice_source_code_range(&Range {
+            location: Location::new(range.location.row(), 0),
+            end_location: Location::new(range.location.row(), range.location.column()),
+        })
+        .to_string()
 }
 
 /// Replace any non-whitespace characters from an indentation string.

src/flake8_annotations/mod.rs

@@ -0,0 +1,155 @@
+pub mod plugins;
+pub mod settings;
+
+#[cfg(test)]
+mod tests {
+    use std::path::Path;
+
+    use anyhow::Result;
+    use rustpython_parser::lexer::LexResult;
+
+    use crate::autofix::fixer;
+    use crate::checks::{Check, CheckCode};
+    use crate::linter::tokenize;
+    use crate::{flake8_annotations, fs, linter, noqa, Settings, SourceCodeLocator};
+
+    fn check_path(path: &Path, settings: &Settings, autofix: &fixer::Mode) -> Result<Vec<Check>> {
+        let contents = fs::read_file(path)?;
+        let tokens: Vec<LexResult> = tokenize(&contents);
+        let locator = SourceCodeLocator::new(&contents);
+        let noqa_line_for = noqa::extract_noqa_line_for(&tokens);
+        linter::check_path(
+            path,
+            &contents,
+            tokens,
+            &locator,
+            &noqa_line_for,
+            settings,
+            autofix,
+        )
+    }
+
+    #[test]
+    fn defaults() -> Result<()> {
+        let mut checks = check_path(
+            Path::new("./resources/test/fixtures/flake8_annotations/annotation_presence.py"),
+            &Settings {
+                ..Settings::for_rules(vec![
+                    CheckCode::ANN001,
+                    CheckCode::ANN002,
+                    CheckCode::ANN003,
+                    CheckCode::ANN101,
+                    CheckCode::ANN102,
+                    CheckCode::ANN201,
+                    CheckCode::ANN202,
+                    CheckCode::ANN204,
+                    CheckCode::ANN205,
+                    CheckCode::ANN206,
+                    CheckCode::ANN401,
+                ])
+            },
+            &fixer::Mode::Generate,
+        )?;
+        checks.sort_by_key(|check| check.location);
+        insta::assert_yaml_snapshot!(checks);
+        Ok(())
+    }
+
+    #[test]
+    fn suppress_dummy_args() -> Result<()> {
+        let mut checks = check_path(
+            Path::new("./resources/test/fixtures/flake8_annotations/suppress_dummy_args.py"),
+            &Settings {
+                flake8_annotations: flake8_annotations::settings::Settings {
+                    mypy_init_return: false,
+                    suppress_dummy_args: true,
+                    suppress_none_returning: false,
+                    allow_star_arg_any: false,
+                },
+                ..Settings::for_rules(vec![
+                    CheckCode::ANN001,
+                    CheckCode::ANN002,
+                    CheckCode::ANN003,
+                    CheckCode::ANN101,
+                    CheckCode::ANN102,
+                ])
+            },
+            &fixer::Mode::Generate,
+        )?;
+        checks.sort_by_key(|check| check.location);
+        insta::assert_yaml_snapshot!(checks);
+        Ok(())
+    }
+
+    #[test]
+    fn mypy_init_return() -> Result<()> {
+        let mut checks = check_path(
+            Path::new("./resources/test/fixtures/flake8_annotations/mypy_init_return.py"),
+            &Settings {
+                flake8_annotations: flake8_annotations::settings::Settings {
+                    mypy_init_return: true,
+                    suppress_dummy_args: false,
+                    suppress_none_returning: false,
+                    allow_star_arg_any: false,
+                },
+                ..Settings::for_rules(vec![
+                    CheckCode::ANN201,
+                    CheckCode::ANN202,
+                    CheckCode::ANN204,
+                    CheckCode::ANN205,
+                    CheckCode::ANN206,
+                ])
+            },
+            &fixer::Mode::Generate,
+        )?;
+        checks.sort_by_key(|check| check.location);
+        insta::assert_yaml_snapshot!(checks);
+        Ok(())
+    }
+
+    #[test]
+    fn suppress_none_returning() -> Result<()> {
+        let mut checks = check_path(
+            Path::new("./resources/test/fixtures/flake8_annotations/suppress_none_returning.py"),
+            &Settings {
+                flake8_annotations: flake8_annotations::settings::Settings {
+                    mypy_init_return: false,
+                    suppress_dummy_args: false,
+                    suppress_none_returning: true,
+                    allow_star_arg_any: false,
+                },
+                ..Settings::for_rules(vec![
+                    CheckCode::ANN201,
+                    CheckCode::ANN202,
+                    CheckCode::ANN204,
+                    CheckCode::ANN205,
+                    CheckCode::ANN206,
+                ])
+            },
+            &fixer::Mode::Generate,
+        )?;
+        checks.sort_by_key(|check| check.location);
+        insta::assert_yaml_snapshot!(checks);
+        Ok(())
+    }
+
+    #[test]
+    fn allow_star_arg_any() -> Result<()> {
+        let mut checks = check_path(
+            Path::new("./resources/test/fixtures/flake8_annotations/allow_star_arg_any.py"),
+            &Settings {
+                flake8_annotations: flake8_annotations::settings::Settings {
+                    mypy_init_return: false,
+                    suppress_dummy_args: false,
+                    suppress_none_returning: false,
+                    allow_star_arg_any: true,
+                },
+                ..Settings::for_rules(vec![CheckCode::ANN401])
+            },
+            &fixer::Mode::Generate,
+        )?;
+        checks.sort_by_key(|check| check.location);
+        insta::assert_yaml_snapshot!(checks);
+        Ok(())
+    }
+}

src/flake8_annotations/plugins.rs

@@ -0,0 +1,376 @@
+use rustpython_ast::{Arguments, Constant, Expr, ExprKind, Stmt, StmtKind};
+
+use crate::ast::types::Range;
+use crate::ast::visitor;
+use crate::ast::visitor::Visitor;
+use crate::check_ast::Checker;
+use crate::checks::{CheckCode, CheckKind};
+use crate::docstrings::definition::{Definition, DefinitionKind};
+use crate::visibility::Visibility;
+use crate::{visibility, Check};
+
+#[derive(Default)]
+struct ReturnStatementVisitor<'a> {
+    returns: Vec<&'a Option<Box<Expr>>>,
+}
+
+impl<'a, 'b> Visitor<'b> for ReturnStatementVisitor<'a>
+where
+    'b: 'a,
+{
+    fn visit_stmt(&mut self, stmt: &'b Stmt) {
+        match &stmt.node {
+            StmtKind::FunctionDef { .. } | StmtKind::AsyncFunctionDef { .. } => {
+                // No recurse.
+            }
+            StmtKind::Return { value } => self.returns.push(value),
+            _ => visitor::walk_stmt(self, stmt),
+        }
+    }
+}
+
+fn is_none_returning(body: &[Stmt]) -> bool {
+    let mut visitor: ReturnStatementVisitor = Default::default();
+    for stmt in body {
+        visitor.visit_stmt(stmt);
+    }
+    for expr in visitor.returns.into_iter().flatten() {
+        if !matches!(
+            expr.node,
+            ExprKind::Constant {
+                value: Constant::None,
+                ..
+            }
+        ) {
+            return false;
+        }
+    }
+    true
+}
+
+/// ANN401
+fn check_dynamically_typed(checker: &mut Checker, annotation: &Expr, name: &str) {
+    if checker.match_typing_module(annotation, "Any") {
+        checker.add_check(Check::new(
+            CheckKind::DynamicallyTypedExpression(name.to_string()),
+            Range::from_located(annotation),
+        ));
+    };
+}
+
+fn match_function_def(stmt: &Stmt) -> (&str, &Arguments, &Option<Box<Expr>>, &Vec<Stmt>) {
+    match &stmt.node {
+        StmtKind::FunctionDef {
+            name,
+            args,
+            returns,
+            body,
+            ..
+        }
+        | StmtKind::AsyncFunctionDef {
+            name,
+            args,
+            returns,
+            body,
+            ..
+        } => (name, args, returns, body),
+        _ => panic!("Found non-FunctionDef in match_name"),
+    }
+}
+
+/// Generate flake8-annotation checks for a given `Definition`.
+pub fn definition(checker: &mut Checker, definition: &Definition, visibility: &Visibility) {
+    // TODO(charlie): Consider using the AST directly here rather than `Definition`.
+    // We could adhere more closely to `flake8-annotations` by defining public
+    // vs. secret vs. protected.
+    match &definition.kind {
+        DefinitionKind::Module => {}
+        DefinitionKind::Package => {}
+        DefinitionKind::Class(_) => {}
+        DefinitionKind::NestedClass(_) => {}
+        DefinitionKind::Function(stmt) | DefinitionKind::NestedFunction(stmt) => {
+            let (name, args, returns, body) = match_function_def(stmt);
+
+            // ANN001, ANN401
+            for arg in args
+                .args
+                .iter()
+                .chain(args.posonlyargs.iter())
+                .chain(args.kwonlyargs.iter())
+            {
+                if let Some(expr) = &arg.node.annotation {
+                    if checker.settings.enabled.contains(&CheckCode::ANN401) {
+                        check_dynamically_typed(checker, expr, &arg.node.arg);
+                    };
+                } else {
+                    if !(checker.settings.flake8_annotations.suppress_dummy_args
+                        && checker.settings.dummy_variable_rgx.is_match(&arg.node.arg))
+                    {
+                        if checker.settings.enabled.contains(&CheckCode::ANN001) {
+                            checker.add_check(Check::new(
+                                CheckKind::MissingTypeFunctionArgument(arg.node.arg.to_string()),
+                                Range::from_located(arg),
+                            ));
+                        }
+                    }
+                }
+            }
+
+            // ANN002, ANN401
+            if let Some(arg) = &args.vararg {
+                if let Some(expr) = &arg.node.annotation {
+                    if !checker.settings.flake8_annotations.allow_star_arg_any {
+                        if checker.settings.enabled.contains(&CheckCode::ANN401) {
+                            let name = arg.node.arg.to_string();
+                            check_dynamically_typed(checker, expr, &format!("*{name}"));
+                        }
+                    }
+                } else {
+                    if !(checker.settings.flake8_annotations.suppress_dummy_args
+                        && checker.settings.dummy_variable_rgx.is_match(&arg.node.arg))
+                    {
+                        if checker.settings.enabled.contains(&CheckCode::ANN002) {
+                            checker.add_check(Check::new(
+                                CheckKind::MissingTypeArgs(arg.node.arg.to_string()),
+                                Range::from_located(arg),
+                            ));
+                        }
+                    }
+                }
+            }
+
+            // ANN003, ANN401
+            if let Some(arg) = &args.kwarg {
+                if let Some(expr) = &arg.node.annotation {
+                    if !checker.settings.flake8_annotations.allow_star_arg_any {
+                        if checker.settings.enabled.contains(&CheckCode::ANN401) {
+                            let name = arg.node.arg.to_string();
+                            check_dynamically_typed(checker, expr, &format!("**{name}"));
+                        }
+                    }
+                } else {
+                    if !(checker.settings.flake8_annotations.suppress_dummy_args
+                        && checker.settings.dummy_variable_rgx.is_match(&arg.node.arg))
+                    {
+                        if checker.settings.enabled.contains(&CheckCode::ANN003) {
+                            checker.add_check(Check::new(
+                                CheckKind::MissingTypeKwargs(arg.node.arg.to_string()),
+                                Range::from_located(arg),
+                            ));
+                        }
+                    }
+                }
+            }
+
+            // ANN201, ANN202, ANN401
+            if let Some(expr) = &returns {
+                if checker.settings.enabled.contains(&CheckCode::ANN401) {
+                    check_dynamically_typed(checker, expr, name);
+                };
+            } else {
+                // Allow omission of return annotation in `__init__` functions, if the function
+                // only returns `None` (explicitly or implicitly).
+                if checker.settings.flake8_annotations.suppress_none_returning
+                    && is_none_returning(body)
+                {
+                    return;
+                }
+
+                match visibility {
+                    Visibility::Public => {
+                        if checker.settings.enabled.contains(&CheckCode::ANN201) {
+                            checker.add_check(Check::new(
+                                CheckKind::MissingReturnTypePublicFunction(name.to_string()),
+                                Range::from_located(stmt),
+                            ));
+                        }
+                    }
+                    Visibility::Private => {
+                        if checker.settings.enabled.contains(&CheckCode::ANN202) {
+                            checker.add_check(Check::new(
+                                CheckKind::MissingReturnTypePrivateFunction(name.to_string()),
+                                Range::from_located(stmt),
+                            ));
+                        }
+                    }
+                }
+            }
+        }
+        DefinitionKind::Method(stmt) => {
+            let (name, args, returns, body) = match_function_def(stmt);
+            let mut has_any_typed_arg = false;
+
+            // ANN001
+            for arg in args
+                .args
+                .iter()
+                .chain(args.posonlyargs.iter())
+                .chain(args.kwonlyargs.iter())
+                .skip(
+                    // If this is a non-static method, skip `cls` or `self`.
+                    usize::from(!visibility::is_staticmethod(stmt)),
+                )
+            {
+                // ANN401 for dynamically typed arguments
+                if let Some(annotation) = &arg.node.annotation {
+                    has_any_typed_arg = true;
+                    if checker.settings.enabled.contains(&CheckCode::ANN401) {
+                        check_dynamically_typed(checker, annotation, &arg.node.arg);
+                    }
+                } else {
+                    if !(checker.settings.flake8_annotations.suppress_dummy_args
+                        && checker.settings.dummy_variable_rgx.is_match(&arg.node.arg))
+                    {
+                        if checker.settings.enabled.contains(&CheckCode::ANN001) {
+                            checker.add_check(Check::new(
+                                CheckKind::MissingTypeFunctionArgument(arg.node.arg.to_string()),
+                                Range::from_located(arg),
+                            ));
+                        }
+                    }
+                }
+            }
+
+            // ANN002, ANN401
+            if let Some(arg) = &args.vararg {
+                has_any_typed_arg = true;
+                if let Some(expr) = &arg.node.annotation {
+                    if !checker.settings.flake8_annotations.allow_star_arg_any {
+                        if checker.settings.enabled.contains(&CheckCode::ANN401) {
+                            let name = arg.node.arg.to_string();
+                            check_dynamically_typed(checker, expr, &format!("*{name}"));
+                        }
+                    }
+                } else {
+                    if !(checker.settings.flake8_annotations.suppress_dummy_args
+                        && checker.settings.dummy_variable_rgx.is_match(&arg.node.arg))
+                    {
+                        if checker.settings.enabled.contains(&CheckCode::ANN002) {
+                            checker.add_check(Check::new(
+                                CheckKind::MissingTypeArgs(arg.node.arg.to_string()),
+                                Range::from_located(arg),
+                            ));
+                        }
+                    }
+                }
+            }
+
+            // ANN003, ANN401
+            if let Some(arg) = &args.kwarg {
+                has_any_typed_arg = true;
+                if let Some(expr) = &arg.node.annotation {
+                    if !checker.settings.flake8_annotations.allow_star_arg_any {
+                        if checker.settings.enabled.contains(&CheckCode::ANN401) {
+                            let name = arg.node.arg.to_string();
+                            check_dynamically_typed(checker, expr, &format!("**{name}"));
+                        }
+                    }
+                } else {
+                    if !(checker.settings.flake8_annotations.suppress_dummy_args
+                        && checker.settings.dummy_variable_rgx.is_match(&arg.node.arg))
+                    {
+                        if checker.settings.enabled.contains(&CheckCode::ANN003) {
+                            checker.add_check(Check::new(
+                                CheckKind::MissingTypeKwargs(arg.node.arg.to_string()),
+                                Range::from_located(arg),
+                            ));
+                        }
+                    }
+                }
+            }
+
+            // ANN101, ANN102
+            if !visibility::is_staticmethod(stmt) {
+                if let Some(arg) = args.args.first() {
+                    if arg.node.annotation.is_none() {
+                        if visibility::is_classmethod(stmt) {
+                            if checker.settings.enabled.contains(&CheckCode::ANN102) {
+                                checker.add_check(Check::new(
+                                    CheckKind::MissingTypeCls(arg.node.arg.to_string()),
+                                    Range::from_located(arg),
+                                ));
+                            }
+                        } else {
+                            if checker.settings.enabled.contains(&CheckCode::ANN101) {
+                                checker.add_check(Check::new(
+                                    CheckKind::MissingTypeSelf(arg.node.arg.to_string()),
+                                    Range::from_located(arg),
+                                ));
+                            }
+                        }
+                    }
+                }
+            }
+
+            // ANN201, ANN202
+            if let Some(expr) = &returns {
+                if checker.settings.enabled.contains(&CheckCode::ANN401) {
+                    check_dynamically_typed(checker, expr, name);
+                }
+            } else {
+                // Allow omission of return annotation in `__init__` functions, if the function
+                // only returns `None` (explicitly or implicitly).
+                if checker.settings.flake8_annotations.suppress_none_returning
+                    && is_none_returning(body)
+                {
+                    return;
+                }
+
+                if visibility::is_classmethod(stmt) {
+                    if checker.settings.enabled.contains(&CheckCode::ANN206) {
+                        checker.add_check(Check::new(
+                            CheckKind::MissingReturnTypeClassMethod(name.to_string()),
+                            Range::from_located(stmt),
+                        ));
+                    }
+                } else if visibility::is_staticmethod(stmt) {
+                    if checker.settings.enabled.contains(&CheckCode::ANN205) {
+                        checker.add_check(Check::new(
+                            CheckKind::MissingReturnTypeStaticMethod(name.to_string()),
+                            Range::from_located(stmt),
+                        ));
+                    }
+                } else if visibility::is_magic(stmt) {
+                    if checker.settings.enabled.contains(&CheckCode::ANN204) {
+                        checker.add_check(Check::new(
+                            CheckKind::MissingReturnTypeMagicMethod(name.to_string()),
+                            Range::from_located(stmt),
+                        ));
+                    }
+                } else if visibility::is_init(stmt) {
+                    // Allow omission of return annotation in `__init__` functions, as long as at
+                    // least one argument is typed.
+                    if checker.settings.enabled.contains(&CheckCode::ANN204) {
+                        if !(checker.settings.flake8_annotations.mypy_init_return
+                            && has_any_typed_arg)
+                        {
+                            checker.add_check(Check::new(
+                                CheckKind::MissingReturnTypeMagicMethod(name.to_string()),
+                                Range::from_located(stmt),
+                            ));
+                        }
+                    }
+                } else {
+                    match visibility {
+                        Visibility::Public => {
+                            if checker.settings.enabled.contains(&CheckCode::ANN201) {
+                                checker.add_check(Check::new(
+                                    CheckKind::MissingReturnTypePublicFunction(name.to_string()),
+                                    Range::from_located(stmt),
+                                ));
+                            }
+                        }
+                        Visibility::Private => {
+                            if checker.settings.enabled.contains(&CheckCode::ANN202) {
+                                checker.add_check(Check::new(
+                                    CheckKind::MissingReturnTypePrivateFunction(name.to_string()),
+                                    Range::from_located(stmt),
+                                ));
+                            }
+                        }
+                    }
+                }
+            }
+        }
+    }
+}

src/flake8_annotations/settings.rs

@@ -0,0 +1,40 @@
+//! Settings for the `flake-annotations` plugin.
+
+use serde::{Deserialize, Serialize};
+
+#[derive(Debug, PartialEq, Eq, Serialize, Deserialize, Default)]
+#[serde(deny_unknown_fields, rename_all = "kebab-case")]
+pub struct Options {
+    /// Allow omission of a return type hint for `__init__` if at least one
+    /// argument is annotated.
+    pub mypy_init_return: Option<bool>,
+    /// Suppress ANN000-level errors for dummy arguments, like `_`.
+    pub suppress_dummy_args: Option<bool>,
+    /// Suppress ANN200-level errors for functions that meet one of the
+    /// following criteria:
+    /// - Contain no `return` statement
+    /// - Explicit `return` statement(s) all return `None` (explicitly or
+    ///   implicitly).
+    pub suppress_none_returning: Option<bool>,
+    /// Suppress ANN401 for dynamically typed *args and **kwargs.
+    pub allow_star_arg_any: Option<bool>,
+}
+
+#[derive(Debug, Hash, Default)]
+pub struct Settings {
+    pub mypy_init_return: bool,
+    pub suppress_dummy_args: bool,
+    pub suppress_none_returning: bool,
+    pub allow_star_arg_any: bool,
+}
+
+impl Settings {
+    pub fn from_options(options: Options) -> Self {
+        Self {
+            mypy_init_return: options.mypy_init_return.unwrap_or_default(),
+            suppress_dummy_args: options.suppress_dummy_args.unwrap_or_default(),
+            suppress_none_returning: options.suppress_none_returning.unwrap_or_default(),
+            allow_star_arg_any: options.allow_star_arg_any.unwrap_or_default(),
+        }
+    }
+}

src/flake8_annotations/snapshots/ruff__flake8_annotations__tests__allow_star_arg_any.snap

@@ -0,0 +1,41 @@
+---
+source: src/flake8_annotations/mod.rs
+expression: checks
+---
+- kind:
+    DynamicallyTypedExpression: a
+  location:
+    row: 10
+    column: 11
+  end_location:
+    row: 10
+    column: 14
+  fix: ~
+- kind:
+    DynamicallyTypedExpression: foo
+  location:
+    row: 15
+    column: 46
+  end_location:
+    row: 15
+    column: 49
+  fix: ~
+- kind:
+    DynamicallyTypedExpression: a
+  location:
+    row: 40
+    column: 28
+  end_location:
+    row: 40
+    column: 31
+  fix: ~
+- kind:
+    DynamicallyTypedExpression: foo_method
+  location:
+    row: 44
+    column: 66
+  end_location:
+    row: 44
+    column: 69
+  fix: ~
+

src/flake8_annotations/snapshots/ruff__flake8_annotations__tests__defaults.snap

@@ -0,0 +1,203 @@
+---
+source: src/flake8_annotations/mod.rs
+expression: checks
+---
+- kind:
+    MissingReturnTypePublicFunction: foo
+  location:
+    row: 4
+    column: 0
+  end_location:
+    row: 9
+    column: 0
+  fix: ~
+- kind:
+    MissingTypeFunctionArgument: a
+  location:
+    row: 4
+    column: 8
+  end_location:
+    row: 4
+    column: 9
+  fix: ~
+- kind:
+    MissingTypeFunctionArgument: b
+  location:
+    row: 4
+    column: 11
+  end_location:
+    row: 4
+    column: 12
+  fix: ~
+- kind:
+    MissingReturnTypePublicFunction: foo
+  location:
+    row: 9
+    column: 0
+  end_location:
+    row: 14
+    column: 0
+  fix: ~
+- kind:
+    MissingTypeFunctionArgument: b
+  location:
+    row: 9
+    column: 16
+  end_location:
+    row: 9
+    column: 17
+  fix: ~
+- kind:
+    MissingTypeFunctionArgument: b
+  location:
+    row: 14
+    column: 16
+  end_location:
+    row: 14
+    column: 17
+  fix: ~
+- kind:
+    MissingReturnTypePublicFunction: foo
+  location:
+    row: 19
+    column: 0
+  end_location:
+    row: 24
+    column: 0
+  fix: ~
+- kind:
+    MissingReturnTypePublicFunction: foo
+  location:
+    row: 24
+    column: 0
+  end_location:
+    row: 29
+    column: 0
+  fix: ~
+- kind:
+    DynamicallyTypedExpression: a
+  location:
+    row: 44
+    column: 11
+  end_location:
+    row: 44
+    column: 14
+  fix: ~
+- kind:
+    DynamicallyTypedExpression: foo
+  location:
+    row: 49
+    column: 46
+  end_location:
+    row: 49
+    column: 49
+  fix: ~
+- kind:
+    DynamicallyTypedExpression: "*args"
+  location:
+    row: 54
+    column: 23
+  end_location:
+    row: 54
+    column: 26
+  fix: ~
+- kind:
+    DynamicallyTypedExpression: "**kwargs"
+  location:
+    row: 54
+    column: 38
+  end_location:
+    row: 54
+    column: 41
+  fix: ~
+- kind:
+    DynamicallyTypedExpression: "*args"
+  location:
+    row: 59
+    column: 23
+  end_location:
+    row: 59
+    column: 26
+  fix: ~
+- kind:
+    DynamicallyTypedExpression: "**kwargs"
+  location:
+    row: 64
+    column: 38
+  end_location:
+    row: 64
+    column: 41
+  fix: ~
+- kind:
+    MissingTypeSelf: self
+  location:
+    row: 74
+    column: 12
+  end_location:
+    row: 74
+    column: 16
+  fix: ~
+- kind:
+    DynamicallyTypedExpression: a
+  location:
+    row: 78
+    column: 28
+  end_location:
+    row: 78
+    column: 31
+  fix: ~
+- kind:
+    DynamicallyTypedExpression: foo
+  location:
+    row: 82
+    column: 66
+  end_location:
+    row: 82
+    column: 69
+  fix: ~
+- kind:
+    DynamicallyTypedExpression: "*params"
+  location:
+    row: 86
+    column: 42
+  end_location:
+    row: 86
+    column: 45
+  fix: ~
+- kind:
+    DynamicallyTypedExpression: "**options"
+  location:
+    row: 86
+    column: 58
+  end_location:
+    row: 86
+    column: 61
+  fix: ~
+- kind:
+    DynamicallyTypedExpression: "*params"
+  location:
+    row: 90
+    column: 42
+  end_location:
+    row: 90
+    column: 45
+  fix: ~
+- kind:
+    DynamicallyTypedExpression: "**options"
+  location:
+    row: 94
+    column: 58
+  end_location:
+    row: 94
+    column: 61
+  fix: ~
+- kind:
+    MissingTypeCls: cls
+  location:
+    row: 104
+    column: 12
+  end_location:
+    row: 104
+    column: 15
+  fix: ~
+

src/flake8_annotations/snapshots/ruff__flake8_annotations__tests__mypy_init_return.snap

@@ -0,0 +1,32 @@
+---
+source: src/flake8_annotations/mod.rs
+expression: checks
+---
+- kind:
+    MissingReturnTypeMagicMethod: __init__
+  location:
+    row: 5
+    column: 4
+  end_location:
+    row: 10
+    column: 0
+  fix: ~
+- kind:
+    MissingReturnTypeMagicMethod: __init__
+  location:
+    row: 11
+    column: 4
+  end_location:
+    row: 16
+    column: 0
+  fix: ~
+- kind:
+    MissingReturnTypePrivateFunction: __init__
+  location:
+    row: 40
+    column: 0
+  end_location:
+    row: 42
+    column: 0
+  fix: ~
+

src/flake8_annotations/snapshots/ruff__flake8_annotations__tests__suppress_dummy_args.snap

@@ -0,0 +1,6 @@
+---
+source: src/flake8_annotations/mod.rs
+expression: checks
+---
+[]
+

src/flake8_annotations/snapshots/ruff__flake8_annotations__tests__suppress_none_returning.snap

@@ -0,0 +1,23 @@
+---
+source: src/flake8_annotations/mod.rs
+expression: checks
+---
+- kind:
+    MissingReturnTypePublicFunction: foo
+  location:
+    row: 45
+    column: 0
+  end_location:
+    row: 50
+    column: 0
+  fix: ~
+- kind:
+    MissingReturnTypePublicFunction: foo
+  location:
+    row: 50
+    column: 0
+  end_location:
+    row: 56
+    column: 0
+  fix: ~
+

src/flake8_bugbear/plugins/assignment_to_os_environ.rs

@@ -0,0 +1,24 @@
+use rustpython_ast::{Expr, ExprKind};
+
+use crate::ast::types::Range;
+use crate::check_ast::Checker;
+use crate::checks::{Check, CheckKind};
+
+/// B003
+pub fn assignment_to_os_environ(checker: &mut Checker, targets: &[Expr]) {
+    if targets.len() == 1 {
+        let target = &targets[0];
+        if let ExprKind::Attribute { value, attr, .. } = &target.node {
+            if attr == "environ" {
+                if let ExprKind::Name { id, .. } = &value.node {
+                    if id == "os" {
+                        checker.add_check(Check::new(
+                            CheckKind::AssignmentToOsEnviron,
+                            Range::from_located(target),
+                        ));
+                    }
+                }
+            }
+        }
+    }
+}

src/flake8_bugbear/plugins/cannot_raise_literal.rs

@@ -0,0 +1,15 @@
+use rustpython_ast::{Expr, ExprKind};
+
+use crate::ast::types::Range;
+use crate::check_ast::Checker;
+use crate::checks::{Check, CheckKind};
+
+/// B016
+pub fn cannot_raise_literal(checker: &mut Checker, expr: &Expr) {
+    if let ExprKind::Constant { .. } = &expr.node {
+        checker.add_check(Check::new(
+            CheckKind::CannotRaiseLiteral,
+            Range::from_located(expr),
+        ));
+    }
+}

src/flake8_bugbear/plugins/duplicate_exceptions.rs

@@ -4,7 +4,7 @@ use itertools::Itertools;
 use rustpython_ast::{Excepthandler, ExcepthandlerKind, Expr, ExprContext, ExprKind, Stmt};
 
 use crate::ast::helpers;
-use crate::ast::types::{CheckLocator, Range};
+use crate::ast::types::Range;
 use crate::autofix::Fix;
 use crate::check_ast::Checker;
 use crate::checks::{Check, CheckCode, CheckKind};
@@ -47,7 +47,7 @@ pub fn duplicate_handler_exceptions(
                 CheckKind::DuplicateHandlerException(
                     duplicates.into_iter().sorted().collect::<Vec<String>>(),
                 ),
-                checker.locate_check(Range::from_located(expr)),
+                Range::from_located(expr),
             );
             if checker.patch() {
                 // TODO(charlie): If we have a single element, remove the tuple.
@@ -106,7 +106,7 @@ pub fn duplicate_exceptions(checker: &mut Checker, stmt: &Stmt, handlers: &[Exce
         for duplicate in duplicates.into_iter().sorted() {
             checker.add_check(Check::new(
                 CheckKind::DuplicateTryBlockException(duplicate),
-                checker.locate_check(Range::from_located(stmt)),
+                Range::from_located(stmt),
             ));
         }
     }