Bump version to 0.0.183

Detect unused arguments

.github/workflows/ci.yaml

@@ -20,6 +20,9 @@ jobs:
       - uses: actions-rs/toolchain@v1
         with:
           profile: minimal
+          toolchain: nightly-2022-11-01
+          override: true
+          components: rustfmt
       - uses: actions/cache@v3
         env:
           cache-name: cache-cargo
@@ -33,6 +36,12 @@ jobs:
             ${{ runner.os }}-build-
             ${{ runner.os }}-
       - run: cargo build --all --release
+      - run: ./target/release/ruff_dev generate-rules-table
+      - run: ./target/release/ruff_dev generate-options
+      - run: git diff --quiet README.md || echo "::error file=README.md::This file is outdated. You may have to rerun 'cargo dev generate-options' and/or 'cargo dev generate-rules-table'."
+      - run: ./target/release/ruff_dev generate-check-code-prefix && cargo fmt -- src/checks_gen.rs
+      - run: git diff --quiet src/checks_gen.rs || echo "::error file=src/checks_gen.rs::This file is outdated. You may have to rerun 'cargo dev generate-check-code-prefix'."
+      - run: git diff --exit-code -- README.md src/checks_gen.rs
 
   cargo_fmt:
     name: "cargo fmt"
@@ -106,7 +115,9 @@ jobs:
             ${{ runner.os }}-build-${{ env.cache-name }}-
             ${{ runner.os }}-build-
             ${{ runner.os }}-
+      - run: pip install black[d]==22.12.0
       - run: cargo test --all
+      - run: cargo test --package ruff --test black_compatibility_test -- --ignored
 
   maturin_build:
     name: "maturin build"

.github/workflows/ruff.yaml

@@ -1,9 +1,8 @@
 name: "[ruff] Release"
 
 on:
-  create:
-    tags:
-      - v*
+  release:
+    types: [published]
 
 concurrency:
   group: ${{ github.workflow }}-${{ github.ref }}

.pre-commit-config.yaml

@@ -1,6 +1,6 @@
 repos:
   - repo: https://github.com/charliermarsh/ruff-pre-commit
-    rev: v0.0.165
+    rev: v0.0.183
     hooks:
       - id: ruff
 

BREAKING_CHANGES.md

@@ -0,0 +1,23 @@
+# Breaking Changes
+
+## 0.0.181
+
+### Files excluded by `.gitignore` are now ignored ([#1234](https://github.com/charliermarsh/ruff/pull/1234))
+
+Ruff will now avoid checking files that are excluded by `.ignore`, `.gitignore`,
+`.git/info/exclude`, and global `gitignore` files. This behavior is powered by the [`ignore`](https://docs.rs/ignore/latest/ignore/struct.WalkBuilder.html#ignore-rules)
+crate, and is applied in addition to Ruff's built-in `exclude` system.
+
+To disable this behavior, set `respect-gitignore = false` in your `pyproject.toml` file.
+
+Note that hidden files (i.e., files and directories prefixed with a `.`) are _not_ ignored by
+default.
+
+## 0.0.178
+
+### Configuration files are now resolved hierarchically ([#1190](https://github.com/charliermarsh/ruff/pull/1190))
+
+`pyproject.toml` files are now resolved hierarchically, such that for each Python file, we find
+the first `pyproject.toml` file in its path, and use that to determine its lint settings.
+
+See the [README](https://github.com/charliermarsh/ruff#pyprojecttoml-discovery) for more.

CONTRIBUTING.md

@@ -105,6 +105,8 @@ You may also want to add the new configuration option to the `flake8-to-ruff` to
 responsible for converting `flake8` configuration files to Ruff's TOML format. This logic
 lives in `flake8_to_ruff/src/converter.rs`.
 
+To update the documentation for supported configuration options, run `cargo dev generate-options`.
+
 ## Release process
 
 As of now, Ruff has an ad hoc release process: releases are cut with high frequency via GitHub

Cargo.lock

@@ -724,7 +724,7 @@ checksum = "0ce7134b9999ecaf8bcd65542e436736ef32ddca1b3e06094cb6ec5755203b80"
 
 [[package]]
 name = "flake8-to-ruff"
-version = "0.0.165-dev.0"
+version = "0.0.183-dev.0"
 dependencies = [
  "anyhow",
  "clap 4.0.29",
@@ -796,6 +796,12 @@ dependencies = [
  "wasm-bindgen",
 ]
 
+[[package]]
+name = "glob"
+version = "0.3.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9b919933a397b79c37e33b77bb2aa3dc8eb6e165ad809e58ff75bc7db2e34574"
+
 [[package]]
 name = "globset"
 version = "0.4.9"
@@ -888,6 +894,24 @@ dependencies = [
  "unicode-normalization",
 ]
 
+[[package]]
+name = "ignore"
+version = "0.4.18"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "713f1b139373f96a2e0ce3ac931cd01ee973c3c5dd7c40c0c2efe96ad2b6751d"
+dependencies = [
+ "crossbeam-utils",
+ "globset",
+ "lazy_static",
+ "log",
+ "memchr",
+ "regex",
+ "same-file",
+ "thread_local",
+ "walkdir",
+ "winapi-util",
+]
+
 [[package]]
 name = "indexmap"
 version = "1.9.2"
@@ -1821,7 +1845,7 @@ dependencies = [
 
 [[package]]
 name = "ruff"
-version = "0.0.165"
+version = "0.0.183"
 dependencies = [
  "annotate-snippets 0.9.1",
  "anyhow",
@@ -1841,7 +1865,9 @@ dependencies = [
  "fern",
  "filetime",
  "getrandom 0.2.8",
+ "glob",
  "globset",
+ "ignore",
  "insta",
  "itertools",
  "libcst",
@@ -1869,12 +1895,13 @@ dependencies = [
  "titlecase",
  "toml",
  "update-informer",
+ "ureq",
  "walkdir",
 ]
 
 [[package]]
 name = "ruff_dev"
-version = "0.0.165"
+version = "0.0.183"
 dependencies = [
  "anyhow",
  "clap 4.0.29",
@@ -1892,7 +1919,7 @@ dependencies = [
 
 [[package]]
 name = "ruff_macros"
-version = "0.0.161"
+version = "0.0.183"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -1935,7 +1962,7 @@ dependencies = [
 [[package]]
 name = "rustpython-ast"
 version = "0.1.0"
-source = "git+https://github.com/RustPython/RustPython.git?rev=28f9f65ccc625f00835d84bbb5fba274dce5aa89#28f9f65ccc625f00835d84bbb5fba274dce5aa89"
+source = "git+https://github.com/RustPython/RustPython.git?rev=8d879a53197f9c73062f6160410bdba796a71cbf#8d879a53197f9c73062f6160410bdba796a71cbf"
 dependencies = [
  "num-bigint",
  "rustpython-common",
@@ -1945,7 +1972,7 @@ dependencies = [
 [[package]]
 name = "rustpython-common"
 version = "0.0.0"
-source = "git+https://github.com/RustPython/RustPython.git?rev=28f9f65ccc625f00835d84bbb5fba274dce5aa89#28f9f65ccc625f00835d84bbb5fba274dce5aa89"
+source = "git+https://github.com/RustPython/RustPython.git?rev=8d879a53197f9c73062f6160410bdba796a71cbf#8d879a53197f9c73062f6160410bdba796a71cbf"
 dependencies = [
  "ascii",
  "cfg-if 1.0.0",
@@ -1968,7 +1995,7 @@ dependencies = [
 [[package]]
 name = "rustpython-compiler-core"
 version = "0.1.2"
-source = "git+https://github.com/RustPython/RustPython.git?rev=28f9f65ccc625f00835d84bbb5fba274dce5aa89#28f9f65ccc625f00835d84bbb5fba274dce5aa89"
+source = "git+https://github.com/RustPython/RustPython.git?rev=8d879a53197f9c73062f6160410bdba796a71cbf#8d879a53197f9c73062f6160410bdba796a71cbf"
 dependencies = [
  "bincode",
  "bitflags",
@@ -1985,7 +2012,7 @@ dependencies = [
 [[package]]
 name = "rustpython-parser"
 version = "0.1.2"
-source = "git+https://github.com/RustPython/RustPython.git?rev=28f9f65ccc625f00835d84bbb5fba274dce5aa89#28f9f65ccc625f00835d84bbb5fba274dce5aa89"
+source = "git+https://github.com/RustPython/RustPython.git?rev=8d879a53197f9c73062f6160410bdba796a71cbf#8d879a53197f9c73062f6160410bdba796a71cbf"
 dependencies = [
  "ahash",
  "anyhow",
@@ -2297,6 +2324,15 @@ dependencies = [
  "syn",
 ]
 
+[[package]]
+name = "thread_local"
+version = "1.1.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5516c27b78311c50bf42c071425c560ac799b11c30b31f87e3081965fe5e0180"
+dependencies = [
+ "once_cell",
+]
+
 [[package]]
 name = "time"
 version = "0.1.45"

Cargo.toml

@@ -6,7 +6,7 @@ members = [
 
 [package]
 name = "ruff"
-version = "0.0.165"
+version = "0.0.183"
 edition = "2021"
 rust-version = "1.65.0"
 
@@ -28,7 +28,9 @@ common-path = { version = "1.0.0" }
 dirs = { version = "4.0.0" }
 fern = { version = "0.6.1" }
 filetime = { version = "0.2.17" }
+glob = { version = "0.3.0" }
 globset = { version = "0.4.9" }
+ignore = { version = "0.4.18" }
 itertools = { version = "0.10.5" }
 libcst = { git = "https://github.com/charliermarsh/LibCST", rev = "f2f0b7a487a8725d161fe8b3ed73a6758b21e177" }
 log = { version = "0.4.17" }
@@ -41,11 +43,11 @@ quick-junit = { version = "0.3.2" }
 rayon = { version = "1.5.3" }
 regex = { version = "1.6.0" }
 ropey = { version = "1.5.0", features = ["cr_lines", "simd"], default-features = false }
-ruff_macros = { version = "0.0.161", path = "ruff_macros" }
+ruff_macros = { version = "0.0.183", path = "ruff_macros" }
 rustc-hash = { version = "1.1.0" }
-rustpython-ast = { features = ["unparse"], git = "https://github.com/RustPython/RustPython.git", rev = "28f9f65ccc625f00835d84bbb5fba274dce5aa89" }
-rustpython-common = { git = "https://github.com/RustPython/RustPython.git", rev = "28f9f65ccc625f00835d84bbb5fba274dce5aa89" }
-rustpython-parser = { features = ["lalrpop"], git = "https://github.com/RustPython/RustPython.git", rev = "28f9f65ccc625f00835d84bbb5fba274dce5aa89" }
+rustpython-ast = { features = ["unparse"], git = "https://github.com/RustPython/RustPython.git", rev = "8d879a53197f9c73062f6160410bdba796a71cbf" }
+rustpython-common = { git = "https://github.com/RustPython/RustPython.git", rev = "8d879a53197f9c73062f6160410bdba796a71cbf" }
+rustpython-parser = { features = ["lalrpop"], git = "https://github.com/RustPython/RustPython.git", rev = "8d879a53197f9c73062f6160410bdba796a71cbf" }
 serde = { version = "1.0.147", features = ["derive"] }
 serde_json = { version = "1.0.87" }
 strum = { version = "0.24.1", features = ["strum_macros"] }
@@ -69,6 +71,7 @@ assert_cmd = { version = "2.0.4" }
 criterion = { version = "0.4.0" }
 insta = { version = "1.19.1", features = ["yaml"] }
 test-case = { version = "2.2.2" }
+ureq = { version = "2.5.0", features = [] }
 
 [features]
 default = ["update-informer"]

LICENSE

@@ -388,6 +388,81 @@ are:
     SOFTWARE.
   """
 
+- flake8-import-conventions, licensed as follows:
+  """
+    MIT License
+
+    Copyright (c) 2021 João Palmeiro
+
+    Permission is hereby granted, free of charge, to any person obtaining a copy
+    of this software and associated documentation files (the "Software"), to deal
+    in the Software without restriction, including without limitation the rights
+    to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+    copies of the Software, and to permit persons to whom the Software is
+    furnished to do so, subject to the following conditions:
+
+    The above copyright notice and this permission notice shall be included in all
+    copies or substantial portions of the Software.
+
+    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+    IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+    FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+    AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+    LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+    OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+    SOFTWARE.
+  """
+
+- flake8-unused-arguments, licensed as follows:
+  """
+    MIT License
+
+    Copyright (c) 2019 Nathan Hoad
+
+    Permission is hereby granted, free of charge, to any person obtaining a copy
+    of this software and associated documentation files (the "Software"), to deal
+    in the Software without restriction, including without limitation the rights
+    to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+    copies of the Software, and to permit persons to whom the Software is
+    furnished to do so, subject to the following conditions:
+
+    The above copyright notice and this permission notice shall be included in all
+    copies or substantial portions of the Software.
+
+    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+    IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+    FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+    AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+    LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+    OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+    SOFTWARE.
+  """
+
+- flake8-simplify, licensed as follows:
+  """
+    MIT License
+
+    Copyright (c) 2020 Martin Thoma
+
+    Permission is hereby granted, free of charge, to any person obtaining a copy
+    of this software and associated documentation files (the "Software"), to deal
+    in the Software without restriction, including without limitation the rights
+    to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+    copies of the Software, and to permit persons to whom the Software is
+    furnished to do so, subject to the following conditions:
+
+    The above copyright notice and this permission notice shall be included in all
+    copies or substantial portions of the Software.
+
+    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+    IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+    FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+    AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+    LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+    OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+    SOFTWARE.
+  """
+
 - isort, licensed as follows:
   """
     The MIT License (MIT)

README.md

@@ -41,6 +41,7 @@ Ruff is extremely actively developed and used in major open-source projects like
 - [Pydantic](https://github.com/pydantic/pydantic)
 - [Saleor](https://github.com/saleor/saleor)
 - [Hatch](https://github.com/pypa/hatch)
+- [Jupyter Server](https://github.com/jupyter-server/jupyter_server)
 
 Read the [launch blog post](https://notes.crmarsh.com/python-tooling-could-be-much-much-faster).
 
@@ -68,31 +69,36 @@ of [Conda](https://docs.conda.io/en/latest/):
 
 1. [Installation and Usage](#installation-and-usage)
 1. [Configuration](#configuration)
-1. [Supported Rules](#supported-rules)
-   1. [Pyflakes (F)](#pyflakes)
-   1. [pycodestyle (E, W)](#pycodestyle)
-   1. [mccabe (C90)](#mccabe)
-   1. [isort (I)](#isort)
-   1. [pydocstyle (D)](#pydocstyle)
-   1. [pyupgrade (UP)](#pyupgrade)
-   1. [pep8-naming (N)](#pep8-naming)
-   1. [flake8-2020 (YTT)](#flake8-2020)
-   1. [flake8-annotations (ANN)](#flake8-annotations)
-   1. [flake8-bandit (S)](#flake8-bandit)
-   1. [flake8-blind-except (BLE)](#flake8-blind-except)
-   1. [flake8-boolean-trap (FBT)](#flake8-boolean-trap)
-   1. [flake8-bugbear (B)](#flake8-bugbear)
-   1. [flake8-builtins (A)](#flake8-builtins)
-   1. [flake8-comprehensions (C4)](#flake8-comprehensions)
-   1. [flake8-debugger (T10)](#flake8-debugger)
-   1. [flake8-print (T20)](#flake8-print)
-   1. [flake8-quotes (Q)](#flake8-quotes)
-   1. [flake8-return (RET)](#flake8-return)
-   1. [flake8-tidy-imports (I25)](#flake8-tidy-imports)
-   1. [eradicate (ERA)](#eradicate)
-   1. [pygrep-hooks (PGH)](#pygrep-hooks)
-   1. [Pylint (PL)](#pylint)
-   1. [Ruff-specific rules (RUF)](#ruff-specific-rules)
+1. [Supported Rules](#supported-rules) <!-- Begin auto-generated table of contents. -->
+   1. [Pyflakes (F)](#pyflakes-f)
+   1. [pycodestyle (E, W)](#pycodestyle-e-w)
+   1. [mccabe (C90)](#mccabe-c90)
+   1. [isort (I)](#isort-i)
+   1. [pydocstyle (D)](#pydocstyle-d)
+   1. [pyupgrade (UP)](#pyupgrade-up)
+   1. [pep8-naming (N)](#pep8-naming-n)
+   1. [flake8-2020 (YTT)](#flake8-2020-ytt)
+   1. [flake8-annotations (ANN)](#flake8-annotations-ann)
+   1. [flake8-bandit (S)](#flake8-bandit-s)
+   1. [flake8-blind-except (BLE)](#flake8-blind-except-ble)
+   1. [flake8-boolean-trap (FBT)](#flake8-boolean-trap-fbt)
+   1. [flake8-bugbear (B)](#flake8-bugbear-b)
+   1. [flake8-builtins (A)](#flake8-builtins-a)
+   1. [flake8-comprehensions (C4)](#flake8-comprehensions-c4)
+   1. [flake8-debugger (T10)](#flake8-debugger-t10)
+   1. [flake8-errmsg (EM)](#flake8-errmsg-em)
+   1. [flake8-import-conventions (ICN)](#flake8-import-conventions-icn)
+   1. [flake8-print (T20)](#flake8-print-t20)
+   1. [flake8-quotes (Q)](#flake8-quotes-q)
+   1. [flake8-return (RET)](#flake8-return-ret)
+   1. [flake8-simplify (SIM)](#flake8-simplify-sim)
+   1. [flake8-tidy-imports (TID)](#flake8-tidy-imports-tid)
+   1. [flake8-unused-arguments (ARG)](#flake8-unused-arguments-arg)
+   1. [eradicate (ERA)](#eradicate-era)
+   1. [pandas-vet (PDV)](#pandas-vet-pdv)
+   1. [pygrep-hooks (PGH)](#pygrep-hooks-pgh)
+   1. [Pylint (PLC, PLE, PLR, PLW)](#pylint-plc-ple-plr-plw)
+   1. [Ruff-specific rules (RUF)](#ruff-specific-rules-ruf)<!-- End auto-generated table of contents. -->
 1. [Editor Integrations](#editor-integrations)
 1. [FAQ](#faq)
 1. [Development](#development)
@@ -118,12 +124,18 @@ For **macOS Homebrew** and **Linuxbrew** users, Ruff is also available as [`ruff
 brew install ruff
 ```
 
-For Conda users, Ruff is also available as [`ruff`](https://anaconda.org/conda-forge/ruff) on `conda-forge`:
+For **Conda** users, Ruff is also available as [`ruff`](https://anaconda.org/conda-forge/ruff) on `conda-forge`:
 
 ```shell
 conda install -c conda-forge ruff
 ```
 
+For **Arch Linux** users, Ruff is also available as [`ruff`](https://archlinux.org/packages/community/x86_64/ruff/) on the official repositories:
+
+```shell
+pacman -S ruff
+```
+
 ### Usage
 
 To run Ruff, try any of the following:
@@ -145,7 +157,7 @@ Ruff also works with [pre-commit](https://pre-commit.com):
 ```yaml
 repos:
   - repo: https://github.com/charliermarsh/ruff-pre-commit
-    rev: v0.0.165
+    rev: v0.0.183
     hooks:
       - id: ruff
 ```
@@ -195,6 +207,13 @@ dummy-variable-rgx = "^(_+|(_+[a-zA-Z0-9_]*[a-zA-Z0-9]+?))$"
 # Assume Python 3.10.
 target-version = "py310"
 
+[tool.ruff.flake8-import-conventions.aliases]
+altair = "alt"
+"matplotlib.pyplot" = "plt"
+numpy = "np"
+pandas = "pd"
+seaborn = "sns"
+
 [tool.ruff.mccabe]
 # Unlike Flake8, default to a complexity level of 10.
 max-complexity = 10
@@ -287,13 +306,15 @@ Options:
       --per-file-ignores <PER_FILE_IGNORES>
           List of mappings from file pattern to code to exclude
       --format <FORMAT>
-          Output serialization format for error messages [default: text] [possible values: text, json, junit, grouped]
+          Output serialization format for error messages [possible values: text, json, junit, grouped, github]
       --show-source
           Show violations with source code
+      --respect-gitignore
+          Respect file exclusions via `.gitignore` and other standard ignore files
       --show-files
           See the files Ruff will be run against with the current settings
       --show-settings
-          See Ruff's settings
+          See the settings Ruff will use to check a given Python file
       --add-noqa
           Enable automatic additions of noqa directives to failing lines
       --dummy-variable-rgx <DUMMY_VARIABLE_RGX>
@@ -314,6 +335,55 @@ Options:
           Print version information
 ```
 
+### `pyproject.toml` discovery
+
+Similar to [ESLint](https://eslint.org/docs/latest/user-guide/configuring/configuration-files#cascading-and-hierarchy),
+Ruff supports hierarchical configuration, such that the "closest" `pyproject.toml` file in the
+directory hierarchy is used for every individual file, with all paths in the `pyproject.toml` file
+(e.g., `exclude` globs, `src` paths) being resolved relative to the directory containing the
+`pyproject.toml` file.
+
+There are a few exceptions to these rules:
+
+1. In locating the "closest" `pyproject.toml` file for a given path, Ruff ignore any
+   `pyproject.toml` files that lack a `[tool.ruff]` section.
+2. If a configuration file is passed directly via `--config`, those settings are used for across
+   files. Any relative paths in that configuration file (like `exclude` globs or `src` paths) are
+   resolved relative to the _current working directory_.
+3. If no `pyproject.toml` file is found in the filesystem hierarchy, Ruff will fall back to using
+   a default configuration. If a user-specific configuration file exists
+   at `${config_dir}/ruff/pyproject.toml`,
+   that file will be used instead of the default configuration, with `${config_dir}` being
+   determined via the [`dirs](https://docs.rs/dirs/4.0.0/dirs/fn.config_dir.html) crate, and all
+   relative paths being again resolved relative to the _current working directory_.
+4. Any `pyproject.toml`-supported settings that are provided on the command-line (e.g., via
+   `--select`) will override the settings in _every_ resolved configuration file.
+
+Unlike [ESLint](https://eslint.org/docs/latest/user-guide/configuring/configuration-files#cascading-and-hierarchy),
+Ruff does not merge settings across configuration files; instead, the "closest" configuration file
+is used, and any parent configuration files are ignored. In lieu of this implicit cascade, Ruff
+supports an [`extend`](#extend) field, which allows you to inherit the settings from another
+`pyproject.toml` file, like so:
+
+```toml
+# Extend the `pyproject.toml` file in the parent directory.
+extend = "../pyproject.toml"
+# But use a different line length.
+line-length = 100
+```
+
+### Python file discovery
+
+When passed a path on the command-line, Ruff will automatically discover all Python files in that
+path, taking into account the [`exclude`](#exclude) and [`extend-exclude`](#extend-exclude) settings
+in each directory's `pyproject.toml` file.
+
+By default, Ruff will also skip any files that are omitted via `.ignore`, `.gitignore`,
+`.git/info/exclude`, and global `gitignore` files (see: [`respect-gitignore`](#respect-gitignore)).
+
+Files that are passed to `ruff` directly are always checked, regardless of the above criteria.
+For example, `ruff /path/to/excluded/file.py` will always check `file.py`.
+
 ### Ignoring errors
 
 To omit a lint check entirely, add it to the "ignore" list via [`ignore`](#ignore) or
@@ -353,7 +423,7 @@ For targeted exclusions across entire files (e.g., "Ignore all F841 violations i
 ### "Action Comments"
 
 Ruff respects `isort`'s ["Action Comments"](https://pycqa.github.io/isort/docs/configuration/action_comments.html)
-(`# isort: skip_file`, `# isort: on`, `# isort: off`, `# isort: skip`, and `isort: split`), which
+(`# isort: skip_file`, `# isort: on`, `# isort: off`, `# isort: skip`, and `# isort: split`), which
 enable selectively enabling and disabling import sorting for blocks of code and other inline
 configuration.
 
@@ -387,8 +457,7 @@ The 🛠 emoji indicates that a rule is automatically fixable by the `--fix` com
 
 <!-- Sections automatically generated by `cargo dev generate-rules-table`. -->
 <!-- Begin auto-generated sections. -->
-
-### Pyflakes
+### Pyflakes (F)
 
 For more, see [Pyflakes](https://pypi.org/project/pyflakes/2.5.0/) on PyPI.
 
@@ -404,14 +473,14 @@ For more, see [Pyflakes](https://pypi.org/project/pyflakes/2.5.0/) on PyPI.
 | F501 | PercentFormatInvalidFormat | '...' % ... has invalid format string: ... |  |
 | F502 | PercentFormatExpectedMapping | '...' % ... expected mapping but got sequence |  |
 | F503 | PercentFormatExpectedSequence | '...' % ... expected sequence but got mapping |  |
-| F504 | PercentFormatExtraNamedArguments | '...' % ... has unused named argument(s): ... |  |
+| F504 | PercentFormatExtraNamedArguments | '...' % ... has unused named argument(s): ... | 🛠 |
 | F505 | PercentFormatMissingArgument | '...' % ... is missing argument(s) for placeholder(s): ... |  |
 | F506 | PercentFormatMixedPositionalAndNamed | '...' % ... has mixed positional and named placeholders |  |
 | F507 | PercentFormatPositionalCountMismatch | '...' % ... has 4 placeholder(s) but 2 substitution(s) |  |
 | F508 | PercentFormatStarRequiresSequence | '...' % ... `*` specifier requires sequence |  |
 | F509 | PercentFormatUnsupportedFormatCharacter | '...' % ... has unsupported format character 'c' |  |
 | F521 | StringDotFormatInvalidFormat | '...'.format(...) has invalid format string: ... |  |
-| F522 | StringDotFormatExtraNamedArguments | '...'.format(...) has unused named argument(s): ... |  |
+| F522 | StringDotFormatExtraNamedArguments | '...'.format(...) has unused named argument(s): ... | 🛠 |
 | F523 | StringDotFormatExtraPositionalArguments | '...'.format(...) has unused arguments at position(s): ... |  |
 | F524 | StringDotFormatMissingArguments | '...'.format(...) is missing argument(s) for placeholder(s): ... |  |
 | F525 | StringDotFormatMixingAutomatic | '...'.format(...) mixes automatic and manual numbering |  |
@@ -430,14 +499,16 @@ For more, see [Pyflakes](https://pypi.org/project/pyflakes/2.5.0/) on PyPI.
 | 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: `...` |  |
+| F811 | RedefinedWhileUnused | Redefinition of unused `...` from line 1 |  |
 | F821 | UndefinedName | Undefined name `...` |  |
 | F822 | UndefinedExport | Undefined name `...` in `__all__` |  |
 | 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 |  |
+| F842 | UnusedAnnotation | Local variable `...` is annotated but never used |  |
 | F901 | RaiseNotImplemented | `raise NotImplemented` should be `raise NotImplementedError` | 🛠 |
 
-### pycodestyle
+### pycodestyle (E, W)
 
 For more, see [pycodestyle](https://pypi.org/project/pycodestyle/2.9.1/) on PyPI.
 
@@ -460,7 +531,7 @@ For more, see [pycodestyle](https://pypi.org/project/pycodestyle/2.9.1/) on PyPI
 | W292 | NoNewLineAtEndOfFile | No newline at end of file |  |
 | W605 | InvalidEscapeSequence | Invalid escape sequence: '\c' |  |
 
-### mccabe
+### mccabe (C90)
 
 For more, see [mccabe](https://pypi.org/project/mccabe/0.7.0/) on PyPI.
 
@@ -468,7 +539,7 @@ For more, see [mccabe](https://pypi.org/project/mccabe/0.7.0/) on PyPI.
 | ---- | ---- | ------- | --- |
 | C901 | FunctionIsTooComplex | `...` is too complex (10) |  |
 
-### isort
+### isort (I)
 
 For more, see [isort](https://pypi.org/project/isort/5.10.1/) on PyPI.
 
@@ -476,7 +547,7 @@ For more, see [isort](https://pypi.org/project/isort/5.10.1/) on PyPI.
 | ---- | ---- | ------- | --- |
 | I001 | UnsortedImports | Import block is un-sorted or un-formatted | 🛠 |
 
-### pydocstyle
+### pydocstyle (D)
 
 For more, see [pydocstyle](https://pypi.org/project/pydocstyle/6.1.1/) on PyPI.
 
@@ -507,6 +578,7 @@ For more, see [pydocstyle](https://pypi.org/project/pydocstyle/6.1.1/) on PyPI.
 | D214 | SectionNotOverIndented | Section is over-indented ("Returns") | 🛠 |
 | D215 | SectionUnderlineNotOverIndented | Section underline is over-indented ("Returns") | 🛠 |
 | D300 | UsesTripleQuotes | Use """triple double quotes""" |  |
+| D301 | UsesRPrefixForBackslashedContent | Use r""" if any backslashes in a docstring |  |
 | 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 |  |
@@ -527,7 +599,7 @@ For more, see [pydocstyle](https://pypi.org/project/pydocstyle/6.1.1/) on PyPI.
 | D418 | SkipDocstring | Function decorated with `@overload` shouldn't contain a docstring |  |
 | D419 | NonEmpty | Docstring is empty |  |
 
-### pyupgrade
+### pyupgrade (UP)
 
 For more, see [pyupgrade](https://pypi.org/project/pyupgrade/3.2.0/) on PyPI.
 
@@ -547,8 +619,9 @@ For more, see [pyupgrade](https://pypi.org/project/pyupgrade/3.2.0/) on PyPI.
 | UP013 | ConvertTypedDictFunctionalToClass | Convert `...` from `TypedDict` functional to class syntax | 🛠 |
 | UP014 | ConvertNamedTupleFunctionalToClass | Convert `...` from `NamedTuple` functional to class syntax | 🛠 |
 | UP015 | RedundantOpenModes | Unnecessary open mode parameters | 🛠 |
+| UP016 | RemoveSixCompat | Unnecessary `six` compatibility usage | 🛠 |
 
-### pep8-naming
+### pep8-naming (N)
 
 For more, see [pep8-naming](https://pypi.org/project/pep8-naming/0.13.2/) on PyPI.
 
@@ -570,7 +643,7 @@ For more, see [pep8-naming](https://pypi.org/project/pep8-naming/0.13.2/) on PyP
 | N817 | CamelcaseImportedAsAcronym | Camelcase `...` imported as acronym `...` |  |
 | N818 | ErrorSuffixOnExceptionName | Exception name `...` should be named with an Error suffix |  |
 
-### flake8-2020
+### flake8-2020 (YTT)
 
 For more, see [flake8-2020](https://pypi.org/project/flake8-2020/1.7.0/) on PyPI.
 
@@ -587,7 +660,7 @@ For more, see [flake8-2020](https://pypi.org/project/flake8-2020/1.7.0/) on PyPI
 | YTT302 | SysVersionCmpStr10 | `sys.version` compared to string (python10), use `sys.version_info` |  |
 | YTT303 | SysVersionSlice1Referenced | `sys.version[:1]` referenced (python10), use `sys.version_info` |  |
 
-### flake8-annotations
+### flake8-annotations (ANN)
 
 For more, see [flake8-annotations](https://pypi.org/project/flake8-annotations/2.9.1/) on PyPI.
 
@@ -605,7 +678,7 @@ For more, see [flake8-annotations](https://pypi.org/project/flake8-annotations/2
 | ANN206 | MissingReturnTypeClassMethod | Missing return type annotation for classmethod `...` |  |
 | ANN401 | DynamicallyTypedExpression | Dynamically typed expressions (typing.Any) are disallowed in `...` |  |
 
-### flake8-bandit
+### flake8-bandit (S)
 
 For more, see [flake8-bandit](https://pypi.org/project/flake8-bandit/4.1.1/) on PyPI.
 
@@ -618,15 +691,15 @@ For more, see [flake8-bandit](https://pypi.org/project/flake8-bandit/4.1.1/) on
 | S106 | HardcodedPasswordFuncArg | Possible hardcoded password: `"..."` |  |
 | S107 | HardcodedPasswordDefault | Possible hardcoded password: `"..."` |  |
 
-### flake8-blind-except
+### flake8-blind-except (BLE)
 
 For more, see [flake8-blind-except](https://pypi.org/project/flake8-blind-except/0.2.1/) on PyPI.
 
 | Code | Name | Message | Fix |
 | ---- | ---- | ------- | --- |
-| BLE001 | BlindExcept | Blind except Exception: statement |  |
+| BLE001 | BlindExcept | Do not catch blind exception: `Exception` |  |
 
-### flake8-boolean-trap
+### flake8-boolean-trap (FBT)
 
 For more, see [flake8-boolean-trap](https://pypi.org/project/flake8-boolean-trap/0.1.0/) on PyPI.
 
@@ -636,7 +709,7 @@ For more, see [flake8-boolean-trap](https://pypi.org/project/flake8-boolean-trap
 | FBT002 | BooleanDefaultValueInFunctionDefinition | Boolean default value in function definition |  |
 | FBT003 | BooleanPositionalValueInFunctionCall | Boolean positional value in function call |  |
 
-### flake8-bugbear
+### flake8-bugbear (B)
 
 For more, see [flake8-bugbear](https://pypi.org/project/flake8-bugbear/22.10.27/) on PyPI.
 
@@ -669,8 +742,9 @@ For more, see [flake8-bugbear](https://pypi.org/project/flake8-bugbear/22.10.27/
 | B026 | StarArgUnpackingAfterKeywordArg | Star-arg unpacking after a keyword argument is strongly discouraged |  |
 | B027 | EmptyMethodWithoutAbstractDecorator | `...` is an empty method in an abstract base class, but has no abstract decorator |  |
 | B904 | RaiseWithoutFromInsideExcept | Within an except clause, raise exceptions with raise ... from err or raise ... from None to distinguish them from errors in exception handling |  |
+| B905 | ZipWithoutExplicitStrict | `zip()` without an explicit `strict=` parameter |  |
 
-### flake8-builtins
+### flake8-builtins (A)
 
 For more, see [flake8-builtins](https://pypi.org/project/flake8-builtins/2.0.1/) on PyPI.
 
@@ -680,7 +754,7 @@ For more, see [flake8-builtins](https://pypi.org/project/flake8-builtins/2.0.1/)
 | A002 | BuiltinArgumentShadowing | Argument `...` is shadowing a python builtin |  |
 | A003 | BuiltinAttributeShadowing | Class attribute `...` is shadowing a python builtin |  |
 
-### flake8-comprehensions
+### flake8-comprehensions (C4)
 
 For more, see [flake8-comprehensions](https://pypi.org/project/flake8-comprehensions/3.10.1/) on PyPI.
 
@@ -697,13 +771,13 @@ For more, see [flake8-comprehensions](https://pypi.org/project/flake8-comprehens
 | 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()` |  |
+| 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)()`) | 🛠 |
 | C417 | UnnecessaryMap | Unnecessary `map` usage (rewrite using a `(list\|set\|dict)` comprehension) |  |
 
-### flake8-debugger
+### flake8-debugger (T10)
 
 For more, see [flake8-debugger](https://pypi.org/project/flake8-debugger/4.1.2/) on PyPI.
 
@@ -711,7 +785,23 @@ For more, see [flake8-debugger](https://pypi.org/project/flake8-debugger/4.1.2/)
 | ---- | ---- | ------- | --- |
 | T100 | Debugger | Import for `...` found |  |
 
-### flake8-print
+### flake8-errmsg (EM)
+
+For more, see [flake8-errmsg](https://pypi.org/project/flake8-errmsg/0.4.0/) on PyPI.
+
+| Code | Name | Message | Fix |
+| ---- | ---- | ------- | --- |
+| EM101 | RawStringInException | Exception must not use a string literal, assign to variable first |  |
+| EM102 | FStringInException | Exception must not use an f-string literal, assign to variable first |  |
+| EM103 | DotFormatInException | Exception must not use a `.format()` string directly, assign to variable first |  |
+
+### flake8-import-conventions (ICN)
+
+| Code | Name | Message | Fix |
+| ---- | ---- | ------- | --- |
+| ICN001 | ImportAliasIsNotConventional | `...` should be imported as `...` |  |
+
+### flake8-print (T20)
 
 For more, see [flake8-print](https://pypi.org/project/flake8-print/5.0.0/) on PyPI.
 
@@ -720,7 +810,7 @@ For more, see [flake8-print](https://pypi.org/project/flake8-print/5.0.0/) on Py
 | T201 | PrintFound | `print` found | 🛠 |
 | T203 | PPrintFound | `pprint` found | 🛠 |
 
-### flake8-quotes
+### flake8-quotes (Q)
 
 For more, see [flake8-quotes](https://pypi.org/project/flake8-quotes/3.3.1/) on PyPI.
 
@@ -731,7 +821,7 @@ For more, see [flake8-quotes](https://pypi.org/project/flake8-quotes/3.3.1/) on
 | Q002 | BadQuotesDocstring | Single quote docstring found but double quotes preferred |  |
 | Q003 | AvoidQuoteEscape | Change outer quotes to avoid escaping inner quotes |  |
 
-### flake8-return
+### flake8-return (RET)
 
 For more, see [flake8-return](https://pypi.org/project/flake8-return/1.2.0/) on PyPI.
 
@@ -746,15 +836,35 @@ For more, see [flake8-return](https://pypi.org/project/flake8-return/1.2.0/) on
 | RET507 | SuperfluousElseContinue | Unnecessary `else` after `continue` statement |  |
 | RET508 | SuperfluousElseBreak | Unnecessary `else` after `break` statement |  |
 
-### flake8-tidy-imports
+### flake8-simplify (SIM)
+
+For more, see [flake8-simplify](https://pypi.org/project/flake8-simplify/0.19.3/) on PyPI.
+
+| Code | Name | Message | Fix |
+| ---- | ---- | ------- | --- |
+| SIM118 | KeyInDict | Use `key in dict` instead of `key in dict.keys()` | 🛠 |
+
+### flake8-tidy-imports (TID)
 
 For more, see [flake8-tidy-imports](https://pypi.org/project/flake8-tidy-imports/4.8.0/) on PyPI.
 
 | Code | Name | Message | Fix |
 | ---- | ---- | ------- | --- |
-| I252 | BannedRelativeImport | Relative imports are banned |  |
+| TID252 | BannedRelativeImport | Relative imports are banned |  |
 
-### eradicate
+### flake8-unused-arguments (ARG)
+
+For more, see [flake8-unused-arguments](https://pypi.org/project/flake8-unused-arguments/0.0.12/) on PyPI.
+
+| Code | Name | Message | Fix |
+| ---- | ---- | ------- | --- |
+| ARG001 | UnusedFunctionArgument | Unused function argument: `...` |  |
+| ARG002 | UnusedMethodArgument | Unused method argument: `...` |  |
+| ARG003 | UnusedClassMethodArgument | Unused class method argument: `...` |  |
+| ARG004 | UnusedStaticMethodArgument | Unused static method argument: `...` |  |
+| ARG005 | UnusedLambdaArgument | Unused lambda argument: `...` |  |
+
+### eradicate (ERA)
 
 For more, see [eradicate](https://pypi.org/project/eradicate/2.1.0/) on PyPI.
 
@@ -762,7 +872,26 @@ For more, see [eradicate](https://pypi.org/project/eradicate/2.1.0/) on PyPI.
 | ---- | ---- | ------- | --- |
 | ERA001 | CommentedOutCode | Found commented-out code | 🛠 |
 
-### pygrep-hooks
+### pandas-vet (PDV)
+
+For more, see [pandas-vet](https://pypi.org/project/pandas-vet/0.2.3/) on PyPI.
+
+| Code | Name | Message | Fix |
+| ---- | ---- | ------- | --- |
+| PDV002 | UseOfInplaceArgument | `inplace=True` should be avoided; it has inconsistent behavior |  |
+| PDV003 | UseOfDotIsNull | `.isna` is preferred to `.isnull`; functionality is equivalent |  |
+| PDV004 | UseOfDotNotNull | `.notna` is preferred to `.notnull`; functionality is equivalent |  |
+| PDV007 | UseOfDotIx | ``ix` i` deprecated; use more explicit `.loc` o` `.iloc` |  |
+| PDV008 | UseOfDotAt | Use `.loc` instead of `.at`.  If speed is important, use numpy. |  |
+| PDV009 | UseOfDotIat | Use `.iloc` instea` of `.iat`.  If speed is important, use numpy. |  |
+| PDV010 | UseOfDotPivotOrUnstack | `.pivot_table` is preferred to `.pivot` or `.unstack`; provides same functionality |  |
+| PDV011 | UseOfDotValues | Use `.to_numpy()` instead of `.values` |  |
+| PDV012 | UseOfDotReadTable | `.read_csv` is preferred to `.read_table`; provides same functionality |  |
+| PDV013 | UseOfDotStack | `.melt` is preferred to `.stack`; provides same functionality |  |
+| PDV015 | UseOfPdMerge | Use `.merge` method instead of `pd.merge` function. They have equivalent functionality. |  |
+| PDV901 | DfIsABadVariableName | `df` is a bad variable name. Be kinder to your future self. |  |
+
+### pygrep-hooks (PGH)
 
 For more, see [pygrep-hooks](https://github.com/pre-commit/pygrep-hooks) on GitHub.
 
@@ -770,7 +899,7 @@ For more, see [pygrep-hooks](https://github.com/pre-commit/pygrep-hooks) on GitH
 | ---- | ---- | ------- | --- |
 | PGH001 | NoEval | No builtin `eval()` allowed |  |
 
-### Pylint
+### Pylint (PLC, PLE, PLR, PLW)
 
 For more, see [Pylint](https://pypi.org/project/pylint/2.15.7/) on PyPI.
 
@@ -779,14 +908,17 @@ For more, see [Pylint](https://pypi.org/project/pylint/2.15.7/) on PyPI.
 | PLC0414 | UselessImportAlias | Import alias does not rename original package | 🛠 |
 | PLC2201 | MisplacedComparisonConstant | Comparison should be ... | 🛠 |
 | PLC3002 | UnnecessaryDirectLambdaCall | Lambda expression called directly. Execute the expression inline instead. |  |
+| PLE0117 | NonlocalWithoutBinding | Nonlocal name `...` found without binding |  |
+| PLE0118 | UsedPriorGlobalDeclaration | Name `...` is used prior to global declaration on line 1 |  |
 | PLE1142 | AwaitOutsideAsync | `await` should be used within an async function |  |
 | PLR0206 | PropertyWithParameters | Cannot have defined parameters for properties |  |
-| PLR0402 | ConsiderUsingFromImport | Consider using `from ... import ...` |  |
-| PLR1701 | ConsiderMergingIsinstance | Consider merging these isinstance calls: `isinstance(..., (...))` |  |
-| PLR1722 | ConsiderUsingSysExit | Consider using `sys.exit()` | 🛠 |
+| PLR0402 | ConsiderUsingFromImport | Use `from ... import ...` in lieu of alias |  |
+| PLR1701 | ConsiderMergingIsinstance | Merge these isinstance calls: `isinstance(..., (...))` |  |
+| PLR1722 | UseSysExit | Use `sys.exit()` instead of `exit` | 🛠 |
 | PLW0120 | UselessElseOnLoop | Else clause on loop without a break statement, remove the else and de-indent all the code inside it |  |
+| PLW0602 | GlobalVariableNotAssigned | Using global for `...` but no assignment is done |  |
 
-### Ruff-specific rules
+### Ruff-specific rules (RUF)
 
 | Code | Name | Message | Fix |
 | ---- | ---- | ------- | --- |
@@ -803,6 +935,37 @@ For more, see [Pylint](https://pypi.org/project/pylint/2.15.7/) on PyPI.
 
 Download the [Ruff VS Code extension](https://marketplace.visualstudio.com/items?itemName=charliermarsh.ruff).
 
+### Language Server Protocol
+
+Ruff is available as a [Language Server Protocol (LSP)](https://microsoft.github.io/language-server-protocol/)
+server, distributed as the [`python-lsp-ruff`](https://github.com/python-lsp/python-lsp-ruff) plugin
+for [`python-lsp-server`](https://github.com/python-lsp/python-lsp-server), both of which are
+installable via [PyPI](https://pypi.org/project/python-lsp-ruff/):
+
+```shell
+pip install python-lsp-server python-lsp-ruff
+```
+
+The LSP server can be used with any editor that supports the Language Server Protocol. For example,
+to use it with Neovim, you would add something like the following to your `init.lua`:
+
+```lua
+require'lspconfig'.pylsp.setup {
+  settings = {
+    pylsp = {
+      plugins = {
+        ruff = {
+          enabled = true
+        }
+      }
+    }
+  },
+}
+```
+
+[`ruffd`](https://github.com/Seamooo/ruffd) is another implementation of the Language Server
+Protocol (LSP) for Ruff, written in Rust.
+
 ### PyCharm
 
 Ruff can be installed as an [External Tool](https://www.jetbrains.com/help/pycharm/configuring-third-party-tools.html)
@@ -815,10 +978,13 @@ Ruff should then appear as a runnable action:
 
 ![Ruff as a runnable action](https://user-images.githubusercontent.com/1309177/193156026-732b0aaf-3dd9-4549-9b4d-2de6d2168a33.png)
 
-### Vim & Neovim (Unofficial)
+### Vim & Neovim
 
-Ruff is available as part of the [coc-pyright](https://github.com/fannheyward/coc-pyright) extension
-for coc.nvim.
+Ruff can be integrated into any editor that supports the Language Server Protocol (LSP) (see:
+[Language Server Protocol](#language-server-protocol)).
+
+Ruff is also available as part of the [coc-pyright](https://github.com/fannheyward/coc-pyright)
+extension for `coc.nvim`.
 
 <details>
 <summary>Ruff can also be integrated via <a href="https://github.com/neovim/nvim-lspconfig/blob/master/doc/server_configurations.md#efm"><code>efm</code></a> in just a <a href="https://github.com/JafarAbdi/myconfigs/blob/6f0b6b2450e92ec8fc50422928cd22005b919110/efm-langserver/config.yaml#L14-L20">few lines</a>.</summary>
@@ -874,11 +1040,6 @@ null_ls.setup({
 
 </details>
 
-### Language Server Protocol (Unofficial)
-
-[`ruffd`](https://github.com/Seamooo/ruffd) is a Rust-based language server for Ruff that implements
-the Language Server Protocol (LSP).
-
 ### GitHub Actions
 
 GitHub Actions has everything you need to run Ruff out-of-the-box:
@@ -921,14 +1082,13 @@ automatically convert your existing configuration.)
 Ruff can be used as a 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.
 
-Under those conditions, Ruff implements every rule in Flake8, with the exception of `F811`.
+Under those conditions, Ruff implements every rule in Flake8.
 
 Ruff also re-implements some of the most popular Flake8 plugins and related code quality tools
 natively, including:
 
-- [`isort`](https://pypi.org/project/isort/)
-- [`pydocstyle`](https://pypi.org/project/pydocstyle/)
-- [`pep8-naming`](https://pypi.org/project/pep8-naming/)
+- [`autoflake`](https://pypi.org/project/autoflake/) (1/7)
+- [`eradicate`](https://pypi.org/project/eradicate/)
 - [`flake8-2020`](https://pypi.org/project/flake8-2020/)
 - [`flake8-annotations`](https://pypi.org/project/flake8-annotations/)
 - [`flake8-bandit`](https://pypi.org/project/flake8-bandit/) (6/40)
@@ -940,22 +1100,29 @@ natively, including:
 - [`flake8-debugger`](https://pypi.org/project/flake8-debugger/)
 - [`flake8-docstrings`](https://pypi.org/project/flake8-docstrings/)
 - [`flake8-eradicate`](https://pypi.org/project/flake8-eradicate/)
+- [`flake8-import-conventions`](https://github.com/joaopalmeiro/flake8-import-conventions)
 - [`flake8-print`](https://pypi.org/project/flake8-print/)
 - [`flake8-quotes`](https://pypi.org/project/flake8-quotes/)
 - [`flake8-return`](https://pypi.org/project/flake8-return/)
 - [`flake8-super`](https://pypi.org/project/flake8-super/)
 - [`flake8-tidy-imports`](https://pypi.org/project/flake8-tidy-imports/) (1/3)
+- [`isort`](https://pypi.org/project/isort/)
 - [`mccabe`](https://pypi.org/project/mccabe/)
-- [`yesqa`](https://github.com/asottile/yesqa)
-- [`eradicate`](https://pypi.org/project/eradicate/)
-- [`pyupgrade`](https://pypi.org/project/pyupgrade/) (16/33)
+- [`pep8-naming`](https://pypi.org/project/pep8-naming/)
+- [`pydocstyle`](https://pypi.org/project/pydocstyle/)
 - [`pygrep-hooks`](https://github.com/pre-commit/pygrep-hooks) (1/10)
-- [`autoflake`](https://pypi.org/project/autoflake/) (1/7)
+- [`pyupgrade`](https://pypi.org/project/pyupgrade/) (16/33)
+- [`yesqa`](https://github.com/asottile/yesqa)
+
+Note that, in some cases, Ruff uses different error code prefixes than would be found in the
+originating Flake8 plugins. For example, Ruff uses `TID252` to represent the `I252` rule from
+`flake8-tidy-imports`. This helps minimize conflicts across plugins and allows any individual plugin
+to be toggled on or off with a single (e.g.) `--select TID`, as opposed to `--select I2` (to avoid
+conflicts with the `isort` rules, like `I001`).
 
 Beyond the rule set, Ruff suffers from the following limitations vis-à-vis Flake8:
 
-1. Ruff does not yet support a few Python 3.9 and 3.10 language features, including structural
-   pattern matching and parenthesized context managers.
+1. Ruff does not yet support structural pattern matching.
 2. Flake8 has a plugin architecture and supports writing custom lint rules. (Instead, popular Flake8
    plugins are re-implemented in Rust as part of Ruff itself.)
 
@@ -975,8 +1142,6 @@ Pylint parity is being tracked in [#689](https://github.com/charliermarsh/ruff/i
 
 Today, Ruff can be used to replace Flake8 when used with any of the following plugins:
 
-- [`pydocstyle`](https://pypi.org/project/pydocstyle/)
-- [`pep8-naming`](https://pypi.org/project/pep8-naming/)
 - [`flake8-2020`](https://pypi.org/project/flake8-2020/)
 - [`flake8-annotations`](https://pypi.org/project/flake8-annotations/)
 - [`flake8-bandit`](https://pypi.org/project/flake8-bandit/) (6/40)
@@ -988,12 +1153,15 @@ Today, Ruff can be used to replace Flake8 when used with any of the following pl
 - [`flake8-debugger`](https://pypi.org/project/flake8-debugger/)
 - [`flake8-docstrings`](https://pypi.org/project/flake8-docstrings/)
 - [`flake8-eradicate`](https://pypi.org/project/flake8-eradicate/)
+- [`flake8-import-conventions`](https://github.com/joaopalmeiro/flake8-import-conventions)
 - [`flake8-print`](https://pypi.org/project/flake8-print/)
 - [`flake8-quotes`](https://pypi.org/project/flake8-quotes/)
 - [`flake8-return`](https://pypi.org/project/flake8-return/)
 - [`flake8-super`](https://pypi.org/project/flake8-super/)
 - [`flake8-tidy-imports`](https://pypi.org/project/flake8-tidy-imports/) (1/3)
 - [`mccabe`](https://pypi.org/project/mccabe/)
+- [`pep8-naming`](https://pypi.org/project/pep8-naming/)
+- [`pydocstyle`](https://pypi.org/project/pydocstyle/)
 
 Ruff can also replace [`isort`](https://pypi.org/project/isort/),
 [`yesqa`](https://github.com/asottile/yesqa), [`eradicate`](https://pypi.org/project/eradicate/),
@@ -1336,7 +1504,7 @@ Exclusions are based on globs, and can be either:
   (to exclude any Python files in `directory`). Note that these paths are relative to the
   project root (e.g., the directory containing your `pyproject.toml`).
 
-Note that you'll typically want to use [`extend_exclude`](#extend_exclude) to modify
+Note that you'll typically want to use [`extend-exclude`](#extend-exclude) to modify
 the excluded paths.
 
 **Default value**: `[".bzr", ".direnv", ".eggs", ".git", ".hg", ".mypy_cache", ".nox", ".pants.d", ".ruff_cache", ".svn", ".tox", ".venv", "__pypackages__", "_build", "buck-out", "build", "dist", "node_modules", "venv"]`
@@ -1352,6 +1520,30 @@ exclude = [".venv"]
 
 ---
 
+#### [`extend`](#extend)
+
+A path to a local `pyproject.toml` file to merge into this configuration.
+
+To resolve the current `pyproject.toml` file, Ruff will first resolve this base
+configuration file, then merge in any properties defined in the current configuration
+file.
+
+**Default value**: `None`
+
+**Type**: `Path`
+
+**Example usage**:
+
+```toml
+[tool.ruff]
+# Extend the `pyproject.toml` file in the parent directory.
+extend = "../pyproject.toml"
+# But use a different line length.
+line-length = 100
+```
+
+---
+
 #### [`extend-exclude`](#extend-exclude)
 
 A list of file patterns to omit from linting, in addition to those specified by `exclude`.
@@ -1449,7 +1641,7 @@ fix = true
 
 A list of check code prefixes to consider autofix-able.
 
-**Default value**: `["A", "ANN", "B", "BLE", "C", "D", "E", "F", "FBT", "I", "M", "N", "Q", "RUF", "S", "T", "U", "W", "YTT"]`
+**Default value**: `["A", "ANN", "ARG", "B", "BLE", "C", "D", "E", "ERA", "F", "FBT", "I", "ICN", "N", "PGH", "PLC", "PLE", "PLR", "PLW", "Q", "RET", "RUF", "S", "T", "TID", "UP", "W", "YTT"]`
 
 **Type**: `Vec<CheckCodePrefix>`
 
@@ -1564,6 +1756,24 @@ any matching files.
 
 ---
 
+#### [`respect-gitignore`](#respect-gitignore)
+
+Whether to automatically exclude files that are ignored by `.ignore`, `.gitignore`,
+`.git/info/exclude`, and global `gitignore` files. Enabled by default.
+
+**Default value**: `true`
+
+**Type**: `bool`
+
+**Example usage**:
+
+```toml
+[tool.ruff]
+respect_gitignore = false
+```
+
+---
+
 #### [`select`](#select)
 
 A list of check code prefixes to enable. Prefixes can specify exact checks (like
@@ -1609,6 +1819,25 @@ show-source = true
 
 The source code paths to consider, e.g., when resolving first- vs. third-party imports.
 
+As an example: given a Python package structure like:
+
+```text
+my_package/
+  pyproject.toml
+  src/
+    my_package/
+      __init__.py
+      foo.py
+      bar.py
+```
+
+The `src` directory should be included in `source` (e.g., `source = ["src"]`), such that
+when resolving imports, `my_package.foo` is considered a first-party import.
+
+This field supports globs. For example, if you have a series of Python packages in
+a `python_modules` directory, `src = ["python_modules/*"]` would expand to incorporate
+all of the packages in that directory.
+
 **Default value**: `["."]`
 
 **Type**: `Vec<PathBuf>`
@@ -1758,6 +1987,67 @@ extend-immutable-calls = ["fastapi.Depends", "fastapi.Query"]
 
 ---
 
+### `flake8-errmsg`
+
+#### [`max-string-length`](#max-string-length)
+
+Maximum string length for string literals in exception messages.
+
+**Default value**: `0`
+
+**Type**: `usize`
+
+**Example usage**:
+
+```toml
+[tool.ruff.flake8-errmsg]
+max-string-length = 20
+```
+
+---
+
+### `flake8-import-conventions`
+
+#### [`aliases`](#aliases)
+
+The conventional aliases for imports. These aliases can be extended by the `extend_aliases` option.
+
+**Default value**: `{"altair": "alt", "matplotlib.pyplot": "plt", "numpy": "np", "pandas": "pd", "seaborn": "sns"}`
+
+**Type**: `FxHashMap<String, String>`
+
+**Example usage**:
+
+```toml
+[tool.ruff.flake8-import-conventions]
+# Declare the default aliases.
+altair = "alt"
+matplotlib.pyplot = "plt"
+numpy = "np"
+pandas = "pd"
+seaborn = "sns"
+```
+
+---
+
+#### [`extend-aliases`](#extend-aliases)
+
+A mapping of modules to their conventional import aliases. These aliases will be added to the `aliases` mapping.
+
+**Default value**: `{}`
+
+**Type**: `FxHashMap<String, String>`
+
+**Example usage**:
+
+```toml
+[tool.ruff.flake8-import-conventions]
+# Declare a custom alias for the `matplotlib` module.
+"dask.dataframe" = "dd"
+```
+
+---
+
 ### `flake8-quotes`
 
 #### [`avoid-escape`](#avoid-escape)
@@ -1903,6 +2193,10 @@ from .utils import (
 )
 ```
 
+Note that this setting is only effective when combined with `combine-as-imports = true`.
+When `combine-as-imports` isn't enabled, every aliased `import from` will be given its
+own line, in which case, wrapping is not necessary.
+
 **Default value**: `false`
 
 **Type**: `bool`
@@ -1912,6 +2206,7 @@ from .utils import (
 ```toml
 [tool.ruff.isort]
 force-wrap-aliases = true
+combine-as-imports = true
 ```
 
 ---

flake8_to_ruff/Cargo.lock

@@ -771,7 +771,7 @@ checksum = "0ce7134b9999ecaf8bcd65542e436736ef32ddca1b3e06094cb6ec5755203b80"
 
 [[package]]
 name = "flake8_to_ruff"
-version = "0.0.165"
+version = "0.0.183"
 dependencies = [
  "anyhow",
  "clap",
@@ -1975,7 +1975,7 @@ dependencies = [
 
 [[package]]
 name = "ruff"
-version = "0.0.165"
+version = "0.0.183"
 dependencies = [
  "anyhow",
  "bincode",
@@ -2028,7 +2028,7 @@ dependencies = [
 [[package]]
 name = "rustpython-ast"
 version = "0.1.0"
-source = "git+https://github.com/RustPython/RustPython.git?rev=28f9f65ccc625f00835d84bbb5fba274dce5aa89#28f9f65ccc625f00835d84bbb5fba274dce5aa89"
+source = "git+https://github.com/RustPython/RustPython.git?rev=8d879a53197f9c73062f6160410bdba796a71cbf#8d879a53197f9c73062f6160410bdba796a71cbf"
 dependencies = [
  "num-bigint",
  "rustpython-common",
@@ -2038,7 +2038,7 @@ dependencies = [
 [[package]]
 name = "rustpython-common"
 version = "0.0.0"
-source = "git+https://github.com/RustPython/RustPython.git?rev=28f9f65ccc625f00835d84bbb5fba274dce5aa89#28f9f65ccc625f00835d84bbb5fba274dce5aa89"
+source = "git+https://github.com/RustPython/RustPython.git?rev=8d879a53197f9c73062f6160410bdba796a71cbf#8d879a53197f9c73062f6160410bdba796a71cbf"
 dependencies = [
  "ascii",
  "cfg-if 1.0.0",
@@ -2061,7 +2061,7 @@ dependencies = [
 [[package]]
 name = "rustpython-compiler-core"
 version = "0.1.2"
-source = "git+https://github.com/RustPython/RustPython.git?rev=28f9f65ccc625f00835d84bbb5fba274dce5aa89#28f9f65ccc625f00835d84bbb5fba274dce5aa89"
+source = "git+https://github.com/RustPython/RustPython.git?rev=8d879a53197f9c73062f6160410bdba796a71cbf#8d879a53197f9c73062f6160410bdba796a71cbf"
 dependencies = [
  "bincode",
  "bitflags",
@@ -2078,7 +2078,7 @@ dependencies = [
 [[package]]
 name = "rustpython-parser"
 version = "0.1.2"
-source = "git+https://github.com/RustPython/RustPython.git?rev=28f9f65ccc625f00835d84bbb5fba274dce5aa89#28f9f65ccc625f00835d84bbb5fba274dce5aa89"
+source = "git+https://github.com/RustPython/RustPython.git?rev=8d879a53197f9c73062f6160410bdba796a71cbf#8d879a53197f9c73062f6160410bdba796a71cbf"
 dependencies = [
  "ahash",
  "anyhow",

flake8_to_ruff/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "flake8-to-ruff"
-version = "0.0.165-dev.0"
+version = "0.0.183-dev.0"
 edition = "2021"
 
 [lib]

flake8_to_ruff/src/converter.rs

@@ -7,7 +7,8 @@ use ruff::flake8_tidy_imports::settings::Strictness;
 use ruff::settings::options::Options;
 use ruff::settings::pyproject::Pyproject;
 use ruff::{
-    flake8_annotations, flake8_bugbear, flake8_quotes, flake8_tidy_imports, mccabe, pep8_naming,
+    flake8_annotations, flake8_bugbear, flake8_errmsg, flake8_quotes, flake8_tidy_imports, mccabe,
+    pep8_naming,
 };
 
 use crate::plugin::Plugin;
@@ -73,6 +74,7 @@ pub fn convert(
     let mut options = Options::default();
     let mut flake8_annotations = flake8_annotations::settings::Options::default();
     let mut flake8_bugbear = flake8_bugbear::settings::Options::default();
+    let mut flake8_errmsg = flake8_errmsg::settings::Options::default();
     let mut flake8_quotes = flake8_quotes::settings::Options::default();
     let mut flake8_tidy_imports = flake8_tidy_imports::settings::Options::default();
     let mut mccabe = mccabe::settings::Options::default();
@@ -194,6 +196,15 @@ pub fn convert(
                     Ok(max_complexity) => mccabe.max_complexity = Some(max_complexity),
                     Err(e) => eprintln!("Unable to parse '{key}' property: {e}"),
                 },
+                // flake8-errmsg
+                "errmsg-max-string-length" | "errmsg_max_string_length" => {
+                    match value.clone().parse::<usize>() {
+                        Ok(max_string_length) => {
+                            flake8_errmsg.max_string_length = Some(max_string_length);
+                        }
+                        Err(e) => eprintln!("Unable to parse '{key}' property: {e}"),
+                    }
+                }
                 // Unknown
                 _ => eprintln!("Skipping unsupported property: {key}"),
             }
@@ -209,6 +220,9 @@ pub fn convert(
     if flake8_bugbear != flake8_bugbear::settings::Options::default() {
         options.flake8_bugbear = Some(flake8_bugbear);
     }
+    if flake8_errmsg != flake8_errmsg::settings::Options::default() {
+        options.flake8_errmsg = Some(flake8_errmsg);
+    }
     if flake8_quotes != flake8_quotes::settings::Options::default() {
         options.flake8_quotes = Some(flake8_quotes);
     }
@@ -246,6 +260,7 @@ mod tests {
             allowed_confusables: None,
             dummy_variable_rgx: None,
             exclude: None,
+            extend: None,
             extend_exclude: None,
             extend_ignore: None,
             extend_select: None,
@@ -257,6 +272,7 @@ mod tests {
             ignore_init_module_imports: None,
             line_length: None,
             per_file_ignores: None,
+            respect_gitignore: None,
             select: Some(vec![
                 CheckCodePrefix::E,
                 CheckCodePrefix::F,
@@ -268,8 +284,10 @@ mod tests {
             unfixable: None,
             flake8_annotations: None,
             flake8_bugbear: None,
+            flake8_errmsg: None,
             flake8_quotes: None,
             flake8_tidy_imports: None,
+            flake8_import_conventions: None,
             isort: None,
             mccabe: None,
             pep8_naming: None,
@@ -290,6 +308,7 @@ mod tests {
             allowed_confusables: None,
             dummy_variable_rgx: None,
             exclude: None,
+            extend: None,
             extend_exclude: None,
             extend_ignore: None,
             extend_select: None,
@@ -301,6 +320,7 @@ mod tests {
             ignore_init_module_imports: None,
             line_length: Some(100),
             per_file_ignores: None,
+            respect_gitignore: None,
             select: Some(vec![
                 CheckCodePrefix::E,
                 CheckCodePrefix::F,
@@ -312,8 +332,10 @@ mod tests {
             unfixable: None,
             flake8_annotations: None,
             flake8_bugbear: None,
+            flake8_errmsg: None,
             flake8_quotes: None,
             flake8_tidy_imports: None,
+            flake8_import_conventions: None,
             isort: None,
             mccabe: None,
             pep8_naming: None,
@@ -334,6 +356,7 @@ mod tests {
             allowed_confusables: None,
             dummy_variable_rgx: None,
             exclude: None,
+            extend: None,
             extend_exclude: None,
             extend_ignore: None,
             extend_select: None,
@@ -345,6 +368,7 @@ mod tests {
             ignore_init_module_imports: None,
             line_length: Some(100),
             per_file_ignores: None,
+            respect_gitignore: None,
             select: Some(vec![
                 CheckCodePrefix::E,
                 CheckCodePrefix::F,
@@ -356,8 +380,10 @@ mod tests {
             unfixable: None,
             flake8_annotations: None,
             flake8_bugbear: None,
+            flake8_errmsg: None,
             flake8_quotes: None,
             flake8_tidy_imports: None,
+            flake8_import_conventions: None,
             isort: None,
             mccabe: None,
             pep8_naming: None,
@@ -378,6 +404,7 @@ mod tests {
             allowed_confusables: None,
             dummy_variable_rgx: None,
             exclude: None,
+            extend: None,
             extend_exclude: None,
             extend_ignore: None,
             extend_select: None,
@@ -389,6 +416,7 @@ mod tests {
             ignore_init_module_imports: None,
             line_length: None,
             per_file_ignores: None,
+            respect_gitignore: None,
             select: Some(vec![
                 CheckCodePrefix::E,
                 CheckCodePrefix::F,
@@ -400,8 +428,10 @@ mod tests {
             unfixable: None,
             flake8_annotations: None,
             flake8_bugbear: None,
+            flake8_errmsg: None,
             flake8_quotes: None,
             flake8_tidy_imports: None,
+            flake8_import_conventions: None,
             isort: None,
             mccabe: None,
             pep8_naming: None,
@@ -422,6 +452,7 @@ mod tests {
             allowed_confusables: None,
             dummy_variable_rgx: None,
             exclude: None,
+            extend: None,
             extend_exclude: None,
             extend_ignore: None,
             extend_select: None,
@@ -433,6 +464,7 @@ mod tests {
             ignore_init_module_imports: None,
             line_length: None,
             per_file_ignores: None,
+            respect_gitignore: None,
             select: Some(vec![
                 CheckCodePrefix::E,
                 CheckCodePrefix::F,
@@ -444,6 +476,7 @@ mod tests {
             unfixable: None,
             flake8_annotations: None,
             flake8_bugbear: None,
+            flake8_errmsg: None,
             flake8_quotes: Some(flake8_quotes::settings::Options {
                 inline_quotes: Some(flake8_quotes::settings::Quote::Single),
                 multiline_quotes: None,
@@ -451,6 +484,7 @@ mod tests {
                 avoid_escape: None,
             }),
             flake8_tidy_imports: None,
+            flake8_import_conventions: None,
             isort: None,
             mccabe: None,
             pep8_naming: None,
@@ -474,6 +508,7 @@ mod tests {
             allowed_confusables: None,
             dummy_variable_rgx: None,
             exclude: None,
+            extend: None,
             extend_exclude: None,
             extend_ignore: None,
             extend_select: None,
@@ -485,6 +520,7 @@ mod tests {
             ignore_init_module_imports: None,
             line_length: None,
             per_file_ignores: None,
+            respect_gitignore: None,
             select: Some(vec![
                 CheckCodePrefix::D100,
                 CheckCodePrefix::D101,
@@ -507,6 +543,7 @@ mod tests {
                 CheckCodePrefix::D214,
                 CheckCodePrefix::D215,
                 CheckCodePrefix::D300,
+                CheckCodePrefix::D301,
                 CheckCodePrefix::D400,
                 CheckCodePrefix::D403,
                 CheckCodePrefix::D404,
@@ -531,8 +568,10 @@ mod tests {
             unfixable: None,
             flake8_annotations: None,
             flake8_bugbear: None,
+            flake8_errmsg: None,
             flake8_quotes: None,
             flake8_tidy_imports: None,
+            flake8_import_conventions: None,
             isort: None,
             mccabe: None,
             pep8_naming: None,
@@ -553,6 +592,7 @@ mod tests {
             allowed_confusables: None,
             dummy_variable_rgx: None,
             exclude: None,
+            extend: None,
             extend_exclude: None,
             extend_ignore: None,
             extend_select: None,
@@ -564,6 +604,7 @@ mod tests {
             ignore_init_module_imports: None,
             line_length: None,
             per_file_ignores: None,
+            respect_gitignore: None,
             select: Some(vec![
                 CheckCodePrefix::E,
                 CheckCodePrefix::F,
@@ -576,6 +617,7 @@ mod tests {
             unfixable: None,
             flake8_annotations: None,
             flake8_bugbear: None,
+            flake8_errmsg: None,
             flake8_quotes: Some(flake8_quotes::settings::Options {
                 inline_quotes: Some(flake8_quotes::settings::Quote::Single),
                 multiline_quotes: None,
@@ -583,6 +625,7 @@ mod tests {
                 avoid_escape: None,
             }),
             flake8_tidy_imports: None,
+            flake8_import_conventions: None,
             isort: None,
             mccabe: None,
             pep8_naming: None,

flake8_to_ruff/src/parser.rs

@@ -135,7 +135,6 @@ fn tokenize_files_to_codes_mapping(value: &str) -> Vec<Token> {
 }
 
 /// 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() {

flake8_to_ruff/src/plugin.rs

@@ -14,12 +14,15 @@ pub enum Plugin {
     Flake8Comprehensions,
     Flake8Debugger,
     Flake8Docstrings,
+    Flake8ErrMsg,
     Flake8Eradicate,
     Flake8Print,
     Flake8Quotes,
     Flake8Return,
+    Flake8Simplify,
     Flake8TidyImports,
     McCabe,
+    PandasVet,
     PEP8Naming,
     Pyupgrade,
 }
@@ -38,11 +41,14 @@ impl FromStr for Plugin {
             "flake8-debugger" => Ok(Plugin::Flake8Debugger),
             "flake8-docstrings" => Ok(Plugin::Flake8Docstrings),
             "flake8-eradicate" => Ok(Plugin::Flake8BlindExcept),
+            "flake8-errmsg" => Ok(Plugin::Flake8ErrMsg),
             "flake8-print" => Ok(Plugin::Flake8Print),
             "flake8-quotes" => Ok(Plugin::Flake8Quotes),
             "flake8-return" => Ok(Plugin::Flake8Return),
+            "flake8-simplify" => Ok(Plugin::Flake8Simplify),
             "flake8-tidy-imports" => Ok(Plugin::Flake8TidyImports),
             "mccabe" => Ok(Plugin::McCabe),
+            "pandas-vet" => Ok(Plugin::PandasVet),
             "pep8-naming" => Ok(Plugin::PEP8Naming),
             "pyupgrade" => Ok(Plugin::Pyupgrade),
             _ => Err(anyhow!("Unknown plugin: {string}")),
@@ -55,18 +61,24 @@ impl Plugin {
         match self {
             Plugin::Flake8Annotations => CheckCodePrefix::ANN,
             Plugin::Flake8Bandit => CheckCodePrefix::S,
+            // TODO(charlie): Handle rename of `B` to `BLE`.
             Plugin::Flake8BlindExcept => CheckCodePrefix::BLE,
             Plugin::Flake8Bugbear => CheckCodePrefix::B,
             Plugin::Flake8Builtins => CheckCodePrefix::A,
             Plugin::Flake8Comprehensions => CheckCodePrefix::C4,
             Plugin::Flake8Debugger => CheckCodePrefix::T1,
             Plugin::Flake8Docstrings => CheckCodePrefix::D,
+            // TODO(charlie): Handle rename of `E` to `ERA`.
             Plugin::Flake8Eradicate => CheckCodePrefix::ERA,
+            Plugin::Flake8ErrMsg => CheckCodePrefix::EM,
             Plugin::Flake8Print => CheckCodePrefix::T2,
             Plugin::Flake8Quotes => CheckCodePrefix::Q,
             Plugin::Flake8Return => CheckCodePrefix::RET,
+            Plugin::Flake8Simplify => CheckCodePrefix::SIM,
             Plugin::Flake8TidyImports => CheckCodePrefix::I25,
             Plugin::McCabe => CheckCodePrefix::C9,
+            // TODO(charlie): Handle rename of `PD` to `PDV`.
+            Plugin::PandasVet => CheckCodePrefix::PDV,
             Plugin::PEP8Naming => CheckCodePrefix::N,
             Plugin::Pyupgrade => CheckCodePrefix::U,
         }
@@ -98,13 +110,16 @@ impl Plugin {
                 DocstringConvention::PEP8.select()
             }
             Plugin::Flake8Eradicate => vec![CheckCodePrefix::ERA],
+            Plugin::Flake8ErrMsg => vec![CheckCodePrefix::EM],
             Plugin::Flake8Print => vec![CheckCodePrefix::T2],
             Plugin::Flake8Quotes => vec![CheckCodePrefix::Q],
             Plugin::Flake8Return => vec![CheckCodePrefix::RET],
-            Plugin::Flake8TidyImports => vec![CheckCodePrefix::I25],
+            Plugin::Flake8Simplify => vec![CheckCodePrefix::SIM],
+            Plugin::Flake8TidyImports => vec![CheckCodePrefix::TID],
             Plugin::McCabe => vec![CheckCodePrefix::C9],
+            Plugin::PandasVet => vec![CheckCodePrefix::PDV],
             Plugin::PEP8Naming => vec![CheckCodePrefix::N],
-            Plugin::Pyupgrade => vec![CheckCodePrefix::U],
+            Plugin::Pyupgrade => vec![CheckCodePrefix::UP],
         }
     }
 }
@@ -162,6 +177,7 @@ impl DocstringConvention {
                 // CheckCodePrefix::D214,
                 // CheckCodePrefix::D215,
                 CheckCodePrefix::D300,
+                CheckCodePrefix::D301,
                 CheckCodePrefix::D400,
                 CheckCodePrefix::D402,
                 CheckCodePrefix::D403,
@@ -209,6 +225,7 @@ impl DocstringConvention {
                 CheckCodePrefix::D214,
                 CheckCodePrefix::D215,
                 CheckCodePrefix::D300,
+                CheckCodePrefix::D301,
                 CheckCodePrefix::D400,
                 // CheckCodePrefix::D402,
                 CheckCodePrefix::D403,
@@ -257,6 +274,7 @@ impl DocstringConvention {
                 CheckCodePrefix::D214,
                 // CheckCodePrefix::D215,
                 CheckCodePrefix::D300,
+                CheckCodePrefix::D301,
                 // CheckCodePrefix::D400,
                 CheckCodePrefix::D402,
                 CheckCodePrefix::D403,
@@ -370,6 +388,9 @@ pub fn infer_plugins_from_options(flake8: &HashMap<String, Option<String>>) -> V
             "staticmethod-decorators" | "staticmethod_decorators" => {
                 plugins.insert(Plugin::PEP8Naming);
             }
+            "max-string-length" | "max_string_length" => {
+                plugins.insert(Plugin::Flake8ErrMsg);
+            }
             _ => {}
         }
     }
@@ -391,10 +412,13 @@ pub fn infer_plugins_from_codes(codes: &BTreeSet<CheckCodePrefix>) -> Vec<Plugin
         Plugin::Flake8Debugger,
         Plugin::Flake8Docstrings,
         Plugin::Flake8Eradicate,
+        Plugin::Flake8ErrMsg,
         Plugin::Flake8Print,
         Plugin::Flake8Quotes,
         Plugin::Flake8Return,
+        Plugin::Flake8Simplify,
         Plugin::Flake8TidyImports,
+        Plugin::PandasVet,
         Plugin::PEP8Naming,
         Plugin::Pyupgrade,
     ]

resources/test/fixtures/README.md

@@ -0,0 +1,3 @@
+# fixtures
+
+Fixture files used for snapshot testing.

resources/test/fixtures/eradicate/ERA001.py

@@ -5,9 +5,11 @@ a = 4
 #foo(1, 2, 3)
 
 def foo(x, y, z):
-    contentet = 1 # print('hello')
+    content = 1 # print('hello')
     print(x, y, z)
 
     # This is a real comment.
     #return True
     return False
+
+#import os  # noqa: ERA001

resources/test/fixtures/flake8_annotations/allow_overload.py

@@ -0,0 +1,49 @@
+from typing import overload
+
+
+@overload
+def foo(i: int) -> "int":
+    ...
+
+
+@overload
+def foo(i: "str") -> "str":
+    ...
+
+
+def foo(i):
+    return i
+
+
+@overload
+def bar(i: int) -> "int":
+    ...
+
+
+@overload
+def bar(i: "str") -> "str":
+    ...
+
+
+class X:
+    def bar(i):
+        return i
+
+
+# TODO(charlie): This third case should raise an error (as in Mypy), because we have a
+# statement between the interfaces and implementation.
+@overload
+def baz(i: int) -> "int":
+    ...
+
+
+@overload
+def baz(i: "str") -> "str":
+    ...
+
+
+x = 1
+
+
+def baz(i):
+    return i

resources/test/fixtures/flake8_blind_except/BLE.py

@@ -53,3 +53,11 @@ try:
         raise e
 except Exception:
     pass
+
+
+try:
+    pass
+except Exception as e:
+    raise bad
+except BaseException:
+    pass

resources/test/fixtures/flake8_bugbear/B009_B010.py

@@ -20,6 +20,8 @@ getattr(foo, "_123abc")
 getattr(foo, "abc123")
 getattr(foo, r"abc123")
 _ = lambda x: getattr(x, "bar")
+if getattr(x, "bar"):
+    pass
 
 # Valid setattr usage
 setattr(foo, bar, None)
@@ -28,6 +30,8 @@ setattr(foo, "123abc", None)
 setattr(foo, r"123\abc", None)
 setattr(foo, "except", None)
 _ = lambda x: setattr(x, "bar", 1)
+if setattr(x, "bar", 1):
+    pass
 
 # Invalid usage
 setattr(foo, "bar", None)

resources/test/fixtures/flake8_bugbear/B905.py

@@ -0,0 +1,10 @@
+zip()
+zip(range(3))
+zip("a", "b")
+zip("a", "b", *zip("c"))
+zip(zip("a"), strict=False)
+zip(zip("a", strict=True))
+
+zip(range(3), strict=True)
+zip("a", "b", strict=False)
+zip("a", "b", "c", strict=True)

resources/test/fixtures/flake8_errmsg/EM.py

@@ -0,0 +1,19 @@
+from __future__ import annotations
+
+
+def f_a():
+    raise RuntimeError("This is an example exception")
+
+
+def f_b():
+    example = "example"
+    raise RuntimeError(f"This is an {example} exception")
+
+
+def f_c():
+    raise RuntimeError("This is an {example} exception".format(example="example"))
+
+
+def f_ok():
+    msg = "hello"
+    raise RuntimeError(msg)

resources/test/fixtures/flake8_import_conventions/custom.py

@@ -0,0 +1,25 @@
+import math  # not checked
+
+import altair  # unconventional
+import dask.array  # unconventional
+import dask.dataframe  # unconventional
+import matplotlib.pyplot  # unconventional
+import numpy  # unconventional
+import pandas  # unconventional
+import seaborn  # unconventional
+
+import altair as altr  # unconventional
+import matplotlib.pyplot as plot  # unconventional
+import dask.array as darray  # unconventional
+import dask.dataframe as ddf  # unconventional
+import numpy as nmp  # unconventional
+import pandas as pdas  # unconventional
+import seaborn as sbrn  # unconventional
+
+import altair as alt  # conventional
+import dask.array as da  # conventional
+import dask.dataframe as dd  # conventional
+import matplotlib.pyplot as plt  # conventional
+import numpy as np  # conventional
+import pandas as pd  # conventional
+import seaborn as sns  # conventional

resources/test/fixtures/flake8_import_conventions/defaults.py

@@ -0,0 +1,19 @@
+import math  # not checked
+
+import altair  # unconventional
+import matplotlib.pyplot  # unconventional
+import numpy  # unconventional
+import pandas  # unconventional
+import seaborn  # unconventional
+
+import altair as altr  # unconventional
+import matplotlib.pyplot as plot  # unconventional
+import numpy as nmp  # unconventional
+import pandas as pdas  # unconventional
+import seaborn as sbrn  # unconventional
+
+import altair as alt  # conventional
+import matplotlib.pyplot as plt  # conventional
+import numpy as np  # conventional
+import pandas as pd  # conventional
+import seaborn as sns  # conventional

resources/test/fixtures/flake8_import_conventions/override_default.py

@@ -0,0 +1,19 @@
+import math  # not checked
+
+import altair  # unconventional
+import matplotlib.pyplot  # unconventional
+import numpy  # unconventional
+import pandas  # unconventional
+import seaborn  # unconventional
+
+import altair as altr  # unconventional
+import matplotlib.pyplot as plot  # unconventional
+import numpy as np  # unconventional
+import pandas as pdas  # unconventional
+import seaborn as sbrn  # unconventional
+
+import altair as alt  # conventional
+import matplotlib.pyplot as plt  # conventional
+import numpy as nmp  # conventional
+import pandas as pd  # conventional
+import seaborn as sns  # conventional

resources/test/fixtures/flake8_import_conventions/remove_default.py

@@ -0,0 +1,19 @@
+import math  # not checked
+
+import altair  # unconventional
+import matplotlib.pyplot  # unconventional
+import numpy  # not checked
+import pandas  # unconventional
+import seaborn  # unconventional
+
+import altair as altr  # unconventional
+import matplotlib.pyplot as plot  # unconventional
+import numpy as nmp  # not checked
+import pandas as pdas  # unconventional
+import seaborn as sbrn  # unconventional
+
+import altair as alt  # conventional
+import matplotlib.pyplot as plt  # conventional
+import numpy as np  # not checked
+import pandas as pd  # conventional
+import seaborn as sns  # conventional

resources/test/fixtures/flake8_return/RET504.py

@@ -130,6 +130,12 @@ def x():
     return val
 
 
+def x():
+    a = 1
+    print(f"a={a}")
+    return a
+
+
 # Test cases for using value for assignment then returning it
 # See:https://github.com/afonasev/flake8-return/issues/47
 def resolve_from_url(self, url: str) -> dict:

resources/test/fixtures/flake8_simplify/SIM118.py

@@ -0,0 +1,12 @@
+key in dict.keys() # SIM118
+
+foo["bar"] in dict.keys() # SIM118
+
+foo() in dict.keys() # SIM118
+
+for key in dict.keys(): # SIM118
+    pass
+
+for key in list(dict.keys()):
+    if some_property(key):
+        del dict[key]

resources/test/fixtures/flake8_unused_arguments/ARG.py

@@ -0,0 +1,137 @@
+from abc import abstractmethod
+from typing_extensions import override
+
+
+###
+# Unused arguments on functions.
+###
+def f(self, x):
+    print("Hello, world!")
+
+
+def f(cls, x):
+    print("Hello, world!")
+
+
+def f(self, x):
+    ...
+
+
+def f(cls, x):
+    ...
+
+
+###
+# Unused arguments on lambdas.
+###
+lambda x: print("Hello, world!")
+
+
+class X:
+    ###
+    # Unused arguments.
+    ###
+    def f(self, x):
+        print("Hello, world!")
+
+    def f(self, /, x):
+        print("Hello, world!")
+
+    def f(cls, x):
+        print("Hello, world!")
+
+    @classmethod
+    def f(cls, x):
+        print("Hello, world!")
+
+    @staticmethod
+    def f(cls, x):
+        print("Hello, world!")
+
+    @staticmethod
+    def f(x):
+        print("Hello, world!")
+
+    ###
+    # Unused arguments attached to empty functions (OK).
+    ###
+    def f(self, x):
+        ...
+
+    def f(self, /, x):
+        ...
+
+    def f(cls, x):
+        ...
+
+    @classmethod
+    def f(cls, x):
+        ...
+
+    @staticmethod
+    def f(cls, x):
+        ...
+
+    @staticmethod
+    def f(x):
+        ...
+
+    ###
+    # Unused functions attached to abstract methods (OK).
+    ###
+    @abstractmethod
+    def f(self, x):
+        print("Hello, world!")
+
+    @abstractmethod
+    def f(self, /, x):
+        print("Hello, world!")
+
+    @abstractmethod
+    def f(cls, x):
+        print("Hello, world!")
+
+    @classmethod
+    @abstractmethod
+    def f(cls, x):
+        print("Hello, world!")
+
+    @staticmethod
+    @abstractmethod
+    def f(cls, x):
+        print("Hello, world!")
+
+    @staticmethod
+    @abstractmethod
+    def f(x):
+        print("Hello, world!")
+
+    ###
+    # Unused functions attached to overrides (OK).
+    ###
+    @override
+    def f(self, x):
+        print("Hello, world!")
+
+    @override
+    def f(self, /, x):
+        print("Hello, world!")
+
+    @override
+    def f(cls, x):
+        print("Hello, world!")
+
+    @classmethod
+    @override
+    def f(cls, x):
+        print("Hello, world!")
+
+    @staticmethod
+    @override
+    def f(cls, x):
+        print("Hello, world!")
+
+    @staticmethod
+    @override
+    def f(x):
+        print("Hello, world!")

resources/test/fixtures/isort/insert_empty_lines.py

@@ -39,3 +39,27 @@ if True:
     import collections
     import typing
     def f(): pass
+
+
+import os
+
+# Comment goes here.
+
+def f():
+    pass
+
+
+import os
+
+# Comment goes here.
+def f():
+    pass
+
+
+import os
+
+# Comment goes here.
+
+# And another.
+def f():
+    pass

resources/test/fixtures/isort/insert_empty_lines.pyi

@@ -0,0 +1,65 @@
+import a
+import b
+x = 1
+import os
+import sys
+def f():
+    pass
+if True:
+    x = 1
+    import collections
+    import typing
+class X: pass
+y = 1
+import os
+import sys
+"""Docstring"""
+
+if True:
+    import os
+
+
+def f():
+    pass
+
+
+if True:
+    import os
+def f():
+    pass
+
+if True:
+    x = 1
+    import collections
+    import typing
+    class X: pass
+
+if True:
+    x = 1
+    import collections
+    import typing
+    def f(): pass
+
+
+import os
+
+# Comment goes here.
+
+def f():
+    pass
+
+
+import os
+
+# Comment goes here.
+def f():
+    pass
+
+
+import os
+
+# Comment goes here.
+
+# And another.
+def f():
+    pass

resources/test/fixtures/isort/leading_prefix.py

@@ -4,3 +4,10 @@ import os
 if True:
     x = 1; import sys
     import os
+
+if True:
+    x = 1; \
+        import os
+
+x = 1; \
+import os

resources/test/fixtures/pycodestyle/constant_literals.py

@@ -0,0 +1,39 @@
+###
+# Errors
+###
+if "abc" is "def":  # F632 (fix)
+    pass
+if "abc" is None:  # F632 (fix, but leaves behind unfixable E711)
+    pass
+if None is "abc":  # F632 (fix, but leaves behind unfixable E711)
+    pass
+if "abc" is False:  # F632 (fix, but leaves behind unfixable E712)
+    pass
+if False is "abc":  # F632 (fix, but leaves behind unfixable E712)
+    pass
+if False == None:  # E711, E712 (fix)
+    pass
+if None == False:  # E711, E712 (fix)
+    pass
+
+###
+# Unfixable errors
+###
+if "abc" == None:  # E711
+    pass
+if None == "abc":  # E711
+    pass
+if "abc" == False:  # E712
+    pass
+if False == "abc":  # E712
+    pass
+
+###
+# Non-errors
+###
+if "def" == "abc":
+    pass
+if False is None:
+    pass
+if None is False:
+    pass

resources/test/fixtures/pyflakes/F401_7.py

@@ -0,0 +1,16 @@
+"""Test: noqa directives."""
+
+from module import (
+    A,  # noqa: F401
+    B,
+)
+
+from module import (
+    A,  # noqa: F401
+    B,  # noqa: F401
+)
+
+from module import (
+    A,
+    B,
+)

resources/test/fixtures/pyflakes/F504.py

@@ -4,3 +4,6 @@ a = "wrong"
 
 hidden = {"a": "!"}
 "%(a)s %(c)s" % {"x": 1, **hidden}  # Ok (cannot see through splat)
+
+"%(a)s" % {"a": 1, r"b": "!"}  # F504 ("b" not used)
+"%(a)s" % {'a': 1, u"b": "!"}  # F504 ("b" not used)

resources/test/fixtures/pyflakes/F541.py

@@ -9,3 +9,4 @@ e = (
 )
 
 g = f"ghi{123:{45}}"
+h = "x" "y" f"z"

resources/test/fixtures/pyflakes/F811_0.py

@@ -0,0 +1,11 @@
+def foo(x):
+    return x
+
+
+@foo
+def bar():
+    pass
+
+
+def bar():
+    pass

resources/test/fixtures/pyflakes/F811_1.py

@@ -0,0 +1 @@
+import fu as FU, bar as FU

resources/test/fixtures/pyflakes/F811_10.py

@@ -0,0 +1,8 @@
+"""Test that importing a module twice using a nested does not issue a warning."""
+try:
+    if True:
+        if True:
+            import os
+except:
+    import os
+os.path

resources/test/fixtures/pyflakes/F811_11.py

@@ -0,0 +1,9 @@
+try:
+    from aa import mixer
+except AttributeError:
+    from bb import mixer
+except RuntimeError:
+    from cc import mixer
+except:
+    from dd import mixer
+mixer(123)

resources/test/fixtures/pyflakes/F811_12.py

@@ -0,0 +1,7 @@
+try:
+    from aa import mixer
+except ImportError:
+    pass
+else:
+    from bb import mixer
+mixer(123)

resources/test/fixtures/pyflakes/F811_13.py

@@ -0,0 +1,8 @@
+try:
+    import funca
+except ImportError:
+    from bb import funca
+    from bb import funcb
+else:
+    from bbb import funcb
+print(funca, funcb)

resources/test/fixtures/pyflakes/F811_14.py

@@ -0,0 +1,10 @@
+try:
+    import b
+except ImportError:
+    b = Ellipsis
+    from bb import a
+else:
+    from aa import a
+finally:
+    a = 42
+print(a, b)

resources/test/fixtures/pyflakes/F811_15.py

@@ -0,0 +1,5 @@
+import fu
+
+
+def fu():
+    pass

resources/test/fixtures/pyflakes/F811_16.py

@@ -0,0 +1,9 @@
+"""Test that shadowing a global with a nested function generates a warning."""
+
+import fu
+
+
+def bar():
+    def baz():
+        def fu():
+            pass

resources/test/fixtures/pyflakes/F811_17.py

@@ -0,0 +1,10 @@
+"""Test that shadowing a global name with a nested function generates a warning."""
+import fu
+
+
+def bar():
+    import fu
+
+    def baz():
+        def fu():
+            pass

resources/test/fixtures/pyflakes/F811_18.py

@@ -0,0 +1,14 @@
+"""Test that a global import which is redefined locally, but used later in another scope does not generate a warning."""
+
+import unittest, transport
+
+
+class GetTransportTestCase(unittest.TestCase):
+    def test_get_transport(self):
+        transport = 'transport'
+        self.assertIsNotNone(transport)
+
+
+class TestTransportMethodArgs(unittest.TestCase):
+    def test_send_defaults(self):
+        transport.Transport()

resources/test/fixtures/pyflakes/F811_19.py

@@ -0,0 +1,7 @@
+"""If an imported name is redefined by a class statement which also uses that name in the bases list, no warning is emitted."""
+
+from fu import bar
+
+
+class bar(bar):
+    pass

resources/test/fixtures/pyflakes/F811_2.py

@@ -0,0 +1 @@
+from moo import fu as FU, bar as FU

resources/test/fixtures/pyflakes/F811_20.py

@@ -0,0 +1,13 @@
+"""
+ Test that shadowing a global with a class attribute does not produce a
+ warning.
+ """
+
+import fu
+
+
+class bar:
+    fu = 1
+
+
+print(fu)

resources/test/fixtures/pyflakes/F811_3.py

@@ -0,0 +1 @@
+import fu; fu = 3

resources/test/fixtures/pyflakes/F811_4.py

@@ -0,0 +1 @@
+import fu; fu, bar = 3

resources/test/fixtures/pyflakes/F811_5.py

@@ -0,0 +1 @@
+import fu; [fu, bar] = 3

resources/test/fixtures/pyflakes/F811_6.py

@@ -0,0 +1,7 @@
+"""Test that importing a module twice within an if block does raise a warning."""
+
+i = 2
+if i == 1:
+    import os
+    import os
+os.path

resources/test/fixtures/pyflakes/F811_7.py

@@ -0,0 +1,8 @@
+"""Test that importing a module twice in if-else blocks does not raise a warning."""
+
+i = 2
+if i == 1:
+    import os
+else:
+    import os
+os.path

resources/test/fixtures/pyflakes/F811_8.py

@@ -0,0 +1,8 @@
+"""Test that importing a module twice in a try block does raise a warning."""
+
+try:
+    import os
+    import os
+except:
+    pass
+os.path

resources/test/fixtures/pyflakes/F811_9.py

@@ -0,0 +1,7 @@
+"""Test that importing a module twice in a try block does not raise a warning."""
+
+try:
+    import os
+except:
+    import os
+os.path

resources/test/fixtures/pyflakes/F821_6.py

@@ -0,0 +1,17 @@
+"""Test: annotated global."""
+
+
+n: int
+
+
+def f():
+    print(n)
+
+
+def g():
+    global n
+    n = 1
+
+
+g()
+f()

resources/test/fixtures/pyflakes/F841_0.py

@@ -10,13 +10,13 @@ except ValueError as e:
     print(e)
 
 
-def f1():
+def f():
     x = 1
     y = 2
     z = x + y
 
 
-def f2():
+def f():
     foo = (1, 2)
     (a, b) = (1, 2)
 
@@ -26,12 +26,12 @@ def f2():
     (x, y) = baz = bar
 
 
-def f3():
+def f():
     locals()
     x = 1
 
 
-def f4():
+def f():
     _ = 1
     __ = 1
     _discarded = 1
@@ -40,26 +40,26 @@ def f4():
 a = 1
 
 
-def f5():
+def f():
     global a
 
-    # Used in `f7` via `nonlocal`.
+    # Used in `c` via `nonlocal`.
     b = 1
 
-    def f6():
+    def c():
         # F841
         b = 1
 
-    def f7():
+    def d():
         nonlocal b
 
 
-def f6():
+def f():
     annotations = []
     assert len([annotations for annotations in annotations])
 
 
-def f7():
+def f():
     def connect():
         return None, None
 
@@ -67,6 +67,22 @@ def f7():
         cursor.execute("SELECT * FROM users")
 
 
-def f8():
-    with open("file") as f, open("") as ((a, b)):
+def f():
+    def connect():
+        return None, None
+
+    with (connect() as (connection, cursor)):
+        cursor.execute("SELECT * FROM users")
+
+
+def f():
+    with open("file") as my_file, open("") as ((this, that)):
+        print("hello")
+
+
+def f():
+    with (
+        open("file") as my_file,
+        open("") as ((this, that)),
+    ):
         print("hello")

resources/test/fixtures/pyflakes/F842.py

@@ -0,0 +1,13 @@
+def f():
+    name: str
+    age: int
+
+
+class A:
+    name: str
+    age: int
+
+
+class B:
+    name: str = "Bob"
+    age: int = 18

resources/test/fixtures/pyflakes/multi_statement_lines.py

@@ -0,0 +1,51 @@
+
+if True:
+    import foo; x = 1
+    import foo;     x = 1
+
+if True:
+    import foo; \
+x = 1
+
+if True:
+    import foo \
+        ; x = 1
+
+
+if True:
+    x = 1; import foo
+
+
+if True:
+    x = 1; \
+         import foo
+
+
+if True:
+    x = 1 \
+        ; import foo
+
+
+if True:
+    x = 1; import foo; x = 1
+    x = 1;     import foo;     x = 1
+
+if True:
+    x = 1; \
+        import foo; \
+    x = 1
+
+if True:
+    x = 1 \
+        ;import foo \
+        ;x = 1
+
+
+# Continuation, but not as the last content in the file.
+x = 1; \
+import foo
+
+# Continuation, followed by end-of-file. (Removing `import foo` would cause a syntax
+# error.)
+x = 1; \
+import foo

resources/test/fixtures/pylint/global_variable_not_assigned.py

@@ -0,0 +1,32 @@
+###
+# Errors.
+###
+def f():
+    global x
+
+
+def f():
+    global x
+
+    print(x)
+
+
+###
+# Non-errors.
+###
+def f():
+    global x
+
+    x = 1
+
+
+def f():
+    global x
+
+    (x, y) = (1, 2)
+
+
+def f():
+    global x
+
+    del x

resources/test/fixtures/pylint/nonlocal_without_binding.py

@@ -0,0 +1,19 @@
+nonlocal x
+
+
+def f():
+    nonlocal x
+
+
+def f():
+    nonlocal y
+
+
+def f():
+    x = 1
+
+    def f():
+        nonlocal x
+
+    def f():
+        nonlocal y

resources/test/fixtures/pylint/used_prior_global_declaration.py

@@ -0,0 +1,148 @@
+###
+# Errors.
+###
+def f():
+    print(x)
+
+    global x
+
+    print(x)
+
+
+def f():
+    global x
+
+    print(x)
+
+    global x
+
+    print(x)
+
+
+def f():
+    print(x)
+
+    global x, y
+
+    print(x)
+
+
+def f():
+    global x, y
+
+    print(x)
+
+    global x, y
+
+    print(x)
+
+
+def f():
+    x = 1
+
+    global x
+
+    x = 1
+
+
+def f():
+    global x
+
+    x = 1
+
+    global x
+
+    x = 1
+
+
+def f():
+    del x
+
+    global x, y
+
+    del x
+
+
+def f():
+    global x, y
+
+    del x
+
+    global x, y
+
+    del x
+
+
+def f():
+    del x
+
+    global x
+
+    del x
+
+
+def f():
+    global x
+
+    del x
+
+    global x
+
+    del x
+
+
+def f():
+    del x
+
+    global x, y
+
+    del x
+
+
+def f():
+    global x, y
+
+    del x
+
+    global x, y
+
+    del x
+
+
+###
+# Non-errors.
+###
+def f():
+    global x
+
+    print(x)
+
+
+def f():
+    global x, y
+
+    print(x)
+
+
+def f():
+    global x
+
+    x = 1
+
+
+def f():
+    global x, y
+
+    x = 1
+
+
+def f():
+    global x
+
+    del x
+
+
+def f():
+    global x, y
+
+    del x

resources/test/fixtures/pylint/useless_else_on_loop.py

@@ -75,7 +75,7 @@ def test_break_in_orelse_deep():
 
 
 def test_break_in_orelse_deep2():
-    """should rise a useless-else-on-loop message, as the break statement is only
+    """should raise a useless-else-on-loop message, as the break statement is only
     for the inner for loop
     """
     for _ in range(10):
@@ -101,3 +101,15 @@ def test_break_in_orelse_deep3():
     else:
         return True
     return False
+
+
+def test_break_in_if_orelse():
+    """should raise a useless-else-on-loop message due to break in else"""
+    for _ in range(10):
+        if 1 < 2:  # pylint: disable=comparison-of-constants
+            pass
+        else:
+            break
+    else:
+        return True
+    return False

resources/test/fixtures/pyproject.toml

@@ -41,3 +41,12 @@ staticmethod-decorators = ["staticmethod"]
 
 [tool.ruff.flake8-tidy-imports]
 ban-relative-imports = "parents"
+
+[tool.ruff.flake8-errmsg]
+max-string-length = 20
+
+[tool.ruff.flake8-import-conventions.aliases]
+pandas = "pd"
+
+[tool.ruff.flake8-import-conventions.extend-aliases]
+"dask.dataframe" = "dd"

resources/test/fixtures/pyupgrade/UP016.py

@@ -0,0 +1,87 @@
+# Replace names by built-in names, whether namespaced or not
+# https://github.com/search?q=%22from+six+import%22&type=code
+import six
+from six.moves import map  # No need
+from six import text_type
+
+six.text_type  # str
+six.binary_type  # bytes
+six.class_types  # (type,)
+six.string_types  # (str,)
+six.integer_types  # (int,)
+six.unichr  # chr
+six.iterbytes  # iter
+six.print_(...)  # print(...)
+six.exec_(c, g, l)  # exec(c, g, l)
+six.advance_iterator(it)  # next(it)
+six.next(it)  # next(it)
+six.callable(x)  # callable(x)
+six.moves.range(x)  # range(x)
+six.moves.xrange(x)  # range(x)
+isinstance(..., six.class_types)  # isinstance(..., type)
+issubclass(..., six.integer_types)  # issubclass(..., int)
+isinstance(..., six.string_types)  # isinstance(..., str)
+
+# Replace call on arg by method call on arg
+six.iteritems(dct)  # dct.items()
+six.iterkeys(dct)  # dct.keys()
+six.itervalues(dct)  # dct.values()
+six.viewitems(dct)  # dct.items()
+six.viewkeys(dct)  # dct.keys()
+six.viewvalues(dct)  # dct.values()
+six.assertCountEqual(self, a1, a2)  # self.assertCountEqual(a1, a2)
+six.assertRaisesRegex(self, e, r, fn)  # self.assertRaisesRegex(e, r, fn)
+six.assertRegex(self, s, r)  # self.assertRegex(s, r)
+
+# Replace call on arg by arg attribute
+six.get_method_function(meth)  # meth.__func__
+six.get_method_self(meth)  # meth.__self__
+six.get_function_closure(fn)  # fn.__closure__
+six.get_function_code(fn)  # fn.__code__
+six.get_function_defaults(fn)  # fn.__defaults__
+six.get_function_globals(fn)  # fn.__globals__
+
+# Replace by string literal
+six.b("...")  # b'...'
+six.u("...")  # '...'
+six.ensure_binary("...")  # b'...'
+six.ensure_str("...")  # '...'
+six.ensure_text("...")  # '...'
+six.b(string)  # no change
+
+# Replace by simple expression
+six.get_unbound_function(meth)  # meth
+six.create_unbound_method(fn, cls)  # fn
+
+# Raise exception
+six.raise_from(exc, exc_from)  # raise exc from exc_from
+six.reraise(tp, exc, tb)  # raise exc.with_traceback(tb)
+six.reraise(*sys.exc_info())  # raise
+
+# Int / Bytes conversion
+six.byte2int(bs)  # bs[0]
+six.indexbytes(bs, i)  # bs[i]
+six.int2byte(i)  # bytes((i, ))
+
+# Special cases for next calls
+next(six.iteritems(dct))  # next(iter(dct.items()))
+next(six.iterkeys(dct))  # next(iter(dct.keys()))
+next(six.itervalues(dct))  # next(iter(dct.values()))
+
+# TODO: To implement
+
+
+# Rewrite classes
+@six.python_2_unicode_compatible  # Remove
+class C(six.Iterator):
+    pass  # class C: pass
+
+
+class C(six.with_metaclass(M, B)):
+    pass  # class C(B, metaclass=M): pass
+
+
+# class C(B, metaclass=M): pass
+@six.add_metaclass(M)
+class C(B):
+    pass

resources/test/project/.gitignore

@@ -0,0 +1 @@
+examples/generated

resources/test/project/README.md

@@ -0,0 +1,89 @@
+# project
+
+An example multi-package Python project used to test setting resolution and other complex
+behaviors.
+
+## Expected behavior
+
+Running from the repo root should pick up and enforce the appropriate settings for each package:
+
+```
+∴ cargo run resources/test/project/
+Found 7 error(s).
+resources/test/project/examples/.dotfiles/script.py:1:1: I001 Import block is un-sorted or un-formatted
+resources/test/project/examples/.dotfiles/script.py:1:8: F401 `numpy` imported but unused
+resources/test/project/examples/.dotfiles/script.py:2:17: F401 `app.app_file` imported but unused
+resources/test/project/examples/docs/docs/file.py:1:1: I001 Import block is un-sorted or un-formatted
+resources/test/project/examples/docs/docs/file.py:8:5: F841 Local variable `x` is assigned to but never used
+resources/test/project/src/file.py:1:8: F401 `os` imported but unused
+resources/test/project/src/import_file.py:1:1: I001 Import block is un-sorted or un-formatted
+6 potentially fixable with the --fix option.
+```
+
+Running from the project directory itself should exhibit the same behavior:
+
+```
+∴ (cd resources/test/project/ && cargo run .)
+Found 7 error(s).
+examples/.dotfiles/script.py:1:1: I001 Import block is un-sorted or un-formatted
+examples/.dotfiles/script.py:1:8: F401 `numpy` imported but unused
+examples/.dotfiles/script.py:2:17: F401 `app.app_file` imported but unused
+examples/docs/docs/file.py:1:1: I001 Import block is un-sorted or un-formatted
+examples/docs/docs/file.py:8:5: F841 Local variable `x` is assigned to but never used
+src/file.py:1:8: F401 `os` imported but unused
+src/import_file.py:1:1: I001 Import block is un-sorted or un-formatted
+6 potentially fixable with the --fix option.
+```
+
+Running from the sub-package directory should exhibit the same behavior, but omit the top-level
+files:
+
+```
+∴ (cd resources/test/project/examples/docs && cargo run .)
+Found 2 error(s).
+docs/file.py:1:1: I001 Import block is un-sorted or un-formatted
+docs/file.py:8:5: F841 Local variable `x` is assigned to but never used
+1 potentially fixable with the --fix option.
+```
+
+`--config` should force Ruff to use the specified `pyproject.toml` for all files, and resolve
+file paths from the current working directory:
+
+```
+∴ (cargo run -- --config=resources/test/project/pyproject.toml resources/test/project/)
+Found 11 error(s).
+resources/test/project/examples/.dotfiles/script.py:1:1: I001 Import block is un-sorted or un-formatted
+resources/test/project/examples/.dotfiles/script.py:1:8: F401 `numpy` imported but unused
+resources/test/project/examples/.dotfiles/script.py:2:17: F401 `app.app_file` imported but unused
+resources/test/project/examples/docs/docs/concepts/file.py:1:8: F401 `os` imported but unused
+resources/test/project/examples/docs/docs/file.py:1:1: I001 Import block is un-sorted or un-formatted
+resources/test/project/examples/docs/docs/file.py:1:8: F401 `os` imported but unused
+resources/test/project/examples/docs/docs/file.py:3:8: F401 `numpy` imported but unused
+resources/test/project/examples/docs/docs/file.py:4:27: F401 `docs.concepts.file` imported but unused
+resources/test/project/examples/excluded/script.py:1:8: F401 `os` imported but unused
+resources/test/project/src/file.py:1:8: F401 `os` imported but unused
+resources/test/project/src/import_file.py:1:1: I001 Import block is un-sorted or un-formatted
+11 potentially fixable with the --fix option.
+```
+
+Running from a parent directory should this "ignore" the `exclude` (hence, `concepts/file.py` gets
+included in the output):
+
+```
+∴ (cd resources/test/project/examples && cargo run -- --config=docs/pyproject.toml .)
+Found 4 error(s).
+docs/docs/concepts/file.py:5:5: F841 Local variable `x` is assigned to but never used
+docs/docs/file.py:1:1: I001 Import block is un-sorted or un-formatted
+docs/docs/file.py:8:5: F841 Local variable `x` is assigned to but never used
+excluded/script.py:5:5: F841 Local variable `x` is assigned to but never used
+1 potentially fixable with the --fix option.
+```
+
+Passing an excluded directory directly should report errors in the contained files:
+
+```
+∴ cargo run resources/test/project/examples/excluded/
+Found 1 error(s).
+resources/test/project/examples/excluded/script.py:1:8: F401 `os` imported but unused
+1 potentially fixable with the --fix option.
+```

resources/test/project/examples/.dotfiles/script.py

@@ -0,0 +1,2 @@
+import numpy as np
+from app import app_file

resources/test/project/examples/docs/docs/concepts/file.py

@@ -0,0 +1,5 @@
+import os
+
+
+def f():
+    x = 1

resources/test/project/examples/docs/docs/file.py

@@ -0,0 +1,8 @@
+import os
+
+import numpy as np
+from docs.concepts import file
+
+
+def f():
+    x = 1

resources/test/project/examples/docs/pyproject.toml

@@ -0,0 +1,7 @@
+[tool.ruff]
+extend = "../../pyproject.toml"
+src = ["."]
+# Enable I001, and re-enable F841, to test extension priority.
+extend-select = ["I001", "F841"]
+extend-ignore = ["F401"]
+extend-exclude = ["./docs/concepts/file.py"]

resources/test/project/examples/excluded/script.py

@@ -0,0 +1,5 @@
+import os
+
+
+def f():
+    x = 1

resources/test/project/pyproject.toml

@@ -0,0 +1,5 @@
+[tool.ruff]
+src = [".", "python_modules/*"]
+exclude = ["examples/excluded"]
+extend-select = ["I001"]
+extend-ignore = ["F841"]

resources/test/project/src/file.py

@@ -0,0 +1,5 @@
+import os
+
+
+def f():
+    x = 1

resources/test/project/src/import_file.py

@@ -0,0 +1,7 @@
+import numpy as np
+from app import app_file
+from core import core_file
+
+np.array([1, 2, 3])
+app_file()
+core_file()

ruff_dev/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "ruff_dev"
-version = "0.0.165"
+version = "0.0.183"
 edition = "2021"
 
 [dependencies]
@@ -11,8 +11,8 @@ itertools = { version = "0.10.5" }
 libcst = { git = "https://github.com/charliermarsh/LibCST", rev = "f2f0b7a487a8725d161fe8b3ed73a6758b21e177" }
 once_cell = { version = "1.16.0" }
 ruff = { path = ".." }
-rustpython-ast = { features = ["unparse"], git = "https://github.com/RustPython/RustPython.git", rev = "28f9f65ccc625f00835d84bbb5fba274dce5aa89" }
-rustpython-common = { git = "https://github.com/RustPython/RustPython.git", rev = "28f9f65ccc625f00835d84bbb5fba274dce5aa89" }
-rustpython-parser = { features = ["lalrpop"], git = "https://github.com/RustPython/RustPython.git", rev = "28f9f65ccc625f00835d84bbb5fba274dce5aa89" }
+rustpython-ast = { features = ["unparse"], git = "https://github.com/RustPython/RustPython.git", rev = "8d879a53197f9c73062f6160410bdba796a71cbf" }
+rustpython-common = { git = "https://github.com/RustPython/RustPython.git", rev = "8d879a53197f9c73062f6160410bdba796a71cbf" }
+rustpython-parser = { features = ["lalrpop"], git = "https://github.com/RustPython/RustPython.git", rev = "8d879a53197f9c73062f6160410bdba796a71cbf" }
 strum = { version = "0.24.1", features = ["strum_macros"] }
 strum_macros = { version = "0.24.3" }

ruff_dev/src/generate_check_code_prefix.rs

@@ -8,7 +8,7 @@ use anyhow::Result;
 use clap::Parser;
 use codegen::{Scope, Type, Variant};
 use itertools::Itertools;
-use ruff::checks::{CheckCode, REDIRECTS};
+use ruff::checks::{CheckCode, CODE_REDIRECTS, PREFIX_REDIRECTS};
 use strum::IntoEnumIterator;
 
 const FILE: &str = "src/checks_gen.rs";
@@ -39,34 +39,26 @@ pub fn main(cli: &Cli) -> Result<()> {
         }
     }
 
-    // Add any aliases (e.g., "U001" to "UP001").
-    for (alias, check_code) in REDIRECTS.iter() {
-        // Compute the length of the prefix and suffix for both codes.
-        let code_str: String = check_code.as_ref().to_string();
-        let code_prefix_len = code_str
-            .chars()
-            .take_while(|char| char.is_alphabetic())
-            .count();
-        let code_suffix_len = code_str.len() - code_prefix_len;
-        let alias_prefix_len = alias
-            .chars()
-            .take_while(|char| char.is_alphabetic())
-            .count();
-        let alias_suffix_len = alias.len() - alias_prefix_len;
-        assert_eq!(code_suffix_len, alias_suffix_len);
-        for i in 0..=code_suffix_len {
-            let source = code_str[..code_prefix_len + i].to_string();
-            let destination = alias[..alias_prefix_len + i].to_string();
-            if source != destination {
-                prefix_to_codes.insert(
-                    destination,
-                    prefix_to_codes
-                        .get(&source)
-                        .unwrap_or_else(|| panic!("Unknown CheckCode: {source:?}"))
-                        .clone(),
-                );
-            }
-        }
+    // Add any prefix aliases (e.g., "U" to "UP").
+    for (alias, source) in PREFIX_REDIRECTS.iter() {
+        prefix_to_codes.insert(
+            (*alias).to_string(),
+            prefix_to_codes
+                .get(&(*source).to_string())
+                .unwrap_or_else(|| panic!("Unknown CheckCode: {source:?}"))
+                .clone(),
+        );
+    }
+
+    // Add any check code aliases (e.g., "U001" to "UP001").
+    for (alias, check_code) in CODE_REDIRECTS.iter() {
+        prefix_to_codes.insert(
+            (*alias).to_string(),
+            prefix_to_codes
+                .get(&check_code.as_ref().to_string())
+                .unwrap_or_else(|| panic!("Unknown CheckCode: {alias:?}"))
+                .clone(),
+        );
     }
 
     let mut scope = Scope::new();
@@ -76,6 +68,7 @@ pub fn main(cli: &Cli) -> Result<()> {
         .new_enum("CheckCodePrefix")
         .vis("pub")
         .derive("EnumString")
+        .derive("AsRefStr")
         .derive("Debug")
         .derive("PartialEq")
         .derive("Eq")
@@ -112,10 +105,10 @@ pub fn main(cli: &Cli) -> Result<()> {
         .line("#[allow(clippy::match_same_arms)]")
         .line("match self {");
     for (prefix, codes) in &prefix_to_codes {
-        if let Some(target) = REDIRECTS.get(&prefix.as_str()) {
+        if let Some(target) = CODE_REDIRECTS.get(&prefix.as_str()) {
             gen = gen.line(format!(
                 "CheckCodePrefix::{prefix} => {{ eprintln!(\"{{}}{{}} {{}}\", \
-                 \"warning\".yellow().bold(), \":\".bold(), \"`{}` has been renamed to \
+                 \"warning\".yellow().bold(), \":\".bold(), \"`{}` has been remapped to \
                  `{}`\".bold()); \n vec![{}] }}",
                 prefix,
                 target.as_ref(),
@@ -124,6 +117,18 @@ pub fn main(cli: &Cli) -> Result<()> {
                     .map(|code| format!("CheckCode::{}", code.as_ref()))
                     .join(", ")
             ));
+        } else if let Some(target) = PREFIX_REDIRECTS.get(&prefix.as_str()) {
+            gen = gen.line(format!(
+                "CheckCodePrefix::{prefix} => {{ eprintln!(\"{{}}{{}} {{}}\", \
+                 \"warning\".yellow().bold(), \":\".bold(), \"`{}` has been remapped to \
+                 `{}`\".bold()); \n vec![{}] }}",
+                prefix,
+                target,
+                codes
+                    .iter()
+                    .map(|code| format!("CheckCode::{}", code.as_ref()))
+                    .join(", ")
+            ));
         } else {
             gen = gen.line(format!(
                 "CheckCodePrefix::{prefix} => vec![{}],",
@@ -170,9 +175,9 @@ pub fn main(cli: &Cli) -> Result<()> {
     output.push('\n');
     output.push_str("use colored::Colorize;");
     output.push('\n');
-    output.push_str("use serde::{{Serialize, Deserialize}};");
+    output.push_str("use serde::{Deserialize, Serialize};");
     output.push('\n');
-    output.push_str("use strum_macros::EnumString;");
+    output.push_str("use strum_macros::{AsRefStr, EnumString};");
     output.push('\n');
     output.push('\n');
     output.push_str("use crate::checks::CheckCode;");
@@ -186,7 +191,9 @@ pub fn main(cli: &Cli) -> Result<()> {
     output.push_str("pub const CATEGORIES: &[CheckCodePrefix] = &[");
     output.push('\n');
     for prefix in prefix_to_codes.keys() {
-        if prefix.chars().all(char::is_alphabetic) {
+        if prefix.chars().all(char::is_alphabetic)
+            && !PREFIX_REDIRECTS.contains_key(&prefix.as_str())
+        {
             output.push_str(&format!("CheckCodePrefix::{prefix},"));
             output.push('\n');
         }

ruff_dev/src/generate_rules_table.rs

@@ -7,11 +7,15 @@ use std::path::PathBuf;
 
 use anyhow::Result;
 use clap::Args;
+use itertools::Itertools;
 use ruff::checks::{CheckCategory, CheckCode};
 use strum::IntoEnumIterator;
 
-const BEGIN_PRAGMA: &str = "<!-- Begin auto-generated sections. -->";
-const END_PRAGMA: &str = "<!-- End auto-generated sections. -->";
+const TABLE_BEGIN_PRAGMA: &str = "<!-- Begin auto-generated sections. -->";
+const TABLE_END_PRAGMA: &str = "<!-- End auto-generated sections. -->";
+
+const TOC_BEGIN_PRAGMA: &str = "<!-- Begin auto-generated table of contents. -->";
+const TOC_END_PRAGMA: &str = "<!-- End auto-generated table of contents. -->";
 
 #[derive(Args)]
 pub struct Cli {
@@ -22,73 +26,91 @@ pub struct Cli {
 
 pub fn main(cli: &Cli) -> Result<()> {
     // Generate the table string.
-    let mut output = String::new();
+    let mut table_out = String::new();
+    let mut toc_out = String::new();
     for check_category in CheckCategory::iter() {
-        output.push_str(&format!("### {}", check_category.title()));
-        output.push('\n');
-        output.push('\n');
+        let codes_csv: String = check_category.codes().iter().map(AsRef::as_ref).join(", ");
+        table_out.push_str(&format!("### {} ({codes_csv})", check_category.title()));
+        table_out.push('\n');
+        table_out.push('\n');
+
+        toc_out.push_str(&format!(
+            "   1. [{} ({})](#{}-{})\n",
+            check_category.title(),
+            codes_csv,
+            check_category.title().to_lowercase().replace(' ', "-"),
+            codes_csv.to_lowercase().replace(',', "-").replace(' ', "")
+        ));
 
         if let Some((url, platform)) = check_category.url() {
-            output.push_str(&format!(
+            table_out.push_str(&format!(
                 "For more, see [{}]({}) on {}.",
                 check_category.title(),
                 url,
                 platform
             ));
-            output.push('\n');
-            output.push('\n');
+            table_out.push('\n');
+            table_out.push('\n');
         }
 
-        output.push_str("| Code | Name | Message | Fix |");
-        output.push('\n');
-        output.push_str("| ---- | ---- | ------- | --- |");
-        output.push('\n');
+        table_out.push_str("| Code | Name | Message | Fix |");
+        table_out.push('\n');
+        table_out.push_str("| ---- | ---- | ------- | --- |");
+        table_out.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!(
+                table_out.push_str(&format!(
                     "| {} | {} | {} | {} |",
                     check_kind.code().as_ref(),
                     check_kind.as_ref(),
                     check_kind.summary().replace('|', r"\|"),
                     fix_token
                 ));
-                output.push('\n');
+                table_out.push('\n');
             }
         }
-        output.push('\n');
+        table_out.push('\n');
     }
 
     if cli.dry_run {
-        print!("{output}");
+        print!("Table of Contents: {toc_out}\n Rules Tables: {table_out}");
     } 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, "{prefix}\n\n")?;
-        write!(f, "{output}")?;
-        write!(f, "{suffix}")?;
+        // Extra newline in the markdown numbered list looks weird
+        replace_readme_section(toc_out.trim_end(), TOC_BEGIN_PRAGMA, TOC_END_PRAGMA)?;
+        replace_readme_section(&table_out, TABLE_BEGIN_PRAGMA, TABLE_END_PRAGMA)?;
     }
 
     Ok(())
 }
+
+fn replace_readme_section(content: &str, begin_pragma: &str, end_pragma: &str) -> Result<()> {
+    // 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)?;
+    writeln!(f, "{prefix}")?;
+    write!(f, "{content}")?;
+    write!(f, "{suffix}")?;
+
+    Ok(())
+}

ruff_macros/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "ruff_macros"
-version = "0.0.161"
+version = "0.0.183"
 edition = "2021"
 
 [lib]

src/ast/branch_detection.rs

@@ -0,0 +1,105 @@
+use std::cmp::Ordering;
+
+use rustc_hash::FxHashMap;
+use rustpython_ast::ExcepthandlerKind::ExceptHandler;
+use rustpython_ast::Stmt;
+use rustpython_parser::ast::StmtKind;
+
+use crate::ast::types::RefEquality;
+
+/// Return the common ancestor of `left` and `right` below `stop`, or `None`.
+fn common_ancestor<'a>(
+    left: &'a RefEquality<'a, Stmt>,
+    right: &'a RefEquality<'a, Stmt>,
+    stop: Option<&'a RefEquality<'a, Stmt>>,
+    depths: &'a FxHashMap<RefEquality<'a, Stmt>, usize>,
+    child_to_parent: &'a FxHashMap<RefEquality<'a, Stmt>, RefEquality<'a, Stmt>>,
+) -> Option<&'a RefEquality<'a, Stmt>> {
+    if let Some(stop) = stop {
+        if left == stop || right == stop {
+            return None;
+        }
+    }
+    if left == right {
+        return Some(left);
+    }
+
+    let left_depth = depths.get(left)?;
+    let right_depth = depths.get(right)?;
+    match left_depth.cmp(right_depth) {
+        Ordering::Less => common_ancestor(
+            left,
+            child_to_parent.get(right)?,
+            stop,
+            depths,
+            child_to_parent,
+        ),
+        Ordering::Equal => common_ancestor(
+            child_to_parent.get(left)?,
+            child_to_parent.get(right)?,
+            stop,
+            depths,
+            child_to_parent,
+        ),
+        Ordering::Greater => common_ancestor(
+            child_to_parent.get(left)?,
+            right,
+            stop,
+            depths,
+            child_to_parent,
+        ),
+    }
+}
+
+/// Return the alternative branches for a given node.
+fn alternatives<'a>(node: &'a RefEquality<'a, Stmt>) -> Vec<Vec<RefEquality<'a, Stmt>>> {
+    match &node.0.node {
+        StmtKind::If { body, .. } => vec![body.iter().map(RefEquality).collect()],
+        StmtKind::Try {
+            body,
+            handlers,
+            orelse,
+            ..
+        } => vec![body.iter().chain(orelse.iter()).map(RefEquality).collect()]
+            .into_iter()
+            .chain(handlers.iter().map(|handler| {
+                let ExceptHandler { body, .. } = &handler.node;
+                body.iter().map(RefEquality).collect()
+            }))
+            .collect(),
+        _ => vec![],
+    }
+}
+
+/// Return `true` if `node` is a descendent of any of the nodes in `ancestors`.
+fn descendant_of<'a>(
+    node: &RefEquality<'a, Stmt>,
+    ancestors: &[RefEquality<'a, Stmt>],
+    stop: &RefEquality<'a, Stmt>,
+    depths: &FxHashMap<RefEquality<'a, Stmt>, usize>,
+    child_to_parent: &FxHashMap<RefEquality<'a, Stmt>, RefEquality<'a, Stmt>>,
+) -> bool {
+    ancestors.iter().any(|ancestor| {
+        common_ancestor(node, ancestor, Some(stop), depths, child_to_parent).is_some()
+    })
+}
+
+/// Return `true` if `left` and `right` are on different branches of an `if` or
+/// `try` statement.
+pub fn different_forks<'a>(
+    left: &RefEquality<'a, Stmt>,
+    right: &RefEquality<'a, Stmt>,
+    depths: &FxHashMap<RefEquality<'a, Stmt>, usize>,
+    child_to_parent: &FxHashMap<RefEquality<'a, Stmt>, RefEquality<'a, Stmt>>,
+) -> bool {
+    if let Some(ancestor) = common_ancestor(left, right, None, depths, child_to_parent) {
+        for items in alternatives(ancestor) {
+            let l = descendant_of(left, &items, ancestor, depths, child_to_parent);
+            let r = descendant_of(right, &items, ancestor, depths, child_to_parent);
+            if l ^ r {
+                return true;
+            }
+        }
+    }
+    false
+}

src/ast/cast.rs

@@ -0,0 +1,9 @@
+use rustpython_ast::{Expr, Stmt, StmtKind};
+
+pub fn decorator_list(stmt: &Stmt) -> &Vec<Expr> {
+    match &stmt.node {
+        StmtKind::FunctionDef { decorator_list, .. }
+        | StmtKind::AsyncFunctionDef { decorator_list, .. } => decorator_list,
+        _ => panic!("Expected StmtKind::FunctionDef | StmtKind::AsyncFunctionDef"),
+    }
+}

src/ast/function_type.rs

@@ -0,0 +1,65 @@
+use rustc_hash::{FxHashMap, FxHashSet};
+use rustpython_ast::Expr;
+
+use crate::ast::helpers::{
+    collect_call_paths, dealias_call_path, match_call_path, to_module_and_member,
+};
+use crate::ast::types::{Scope, ScopeKind};
+
+const CLASS_METHODS: [&str; 3] = ["__new__", "__init_subclass__", "__class_getitem__"];
+const METACLASS_BASES: [(&str, &str); 2] = [("", "type"), ("abc", "ABCMeta")];
+
+pub enum FunctionType {
+    Function,
+    Method,
+    ClassMethod,
+    StaticMethod,
+}
+
+/// Classify a function based on its scope, name, and decorators.
+pub fn classify(
+    scope: &Scope,
+    name: &str,
+    decorator_list: &[Expr],
+    from_imports: &FxHashMap<&str, FxHashSet<&str>>,
+    import_aliases: &FxHashMap<&str, &str>,
+    classmethod_decorators: &[String],
+    staticmethod_decorators: &[String],
+) -> FunctionType {
+    let ScopeKind::Class(scope) = &scope.kind else {
+        return FunctionType::Function;
+    };
+    // Special-case class method, like `__new__`.
+    if CLASS_METHODS.contains(&name)
+        || scope.bases.iter().any(|expr| {
+            // The class itself extends a known metaclass, so all methods are class methods.
+            let call_path = dealias_call_path(collect_call_paths(expr), import_aliases);
+            METACLASS_BASES
+                .iter()
+                .any(|(module, member)| match_call_path(&call_path, module, member, from_imports))
+        })
+        || decorator_list.iter().any(|expr| {
+            // The method is decorated with a class method decorator (like `@classmethod`).
+            let call_path = dealias_call_path(collect_call_paths(expr), import_aliases);
+            classmethod_decorators.iter().any(|decorator| {
+                let (module, member) = to_module_and_member(decorator);
+                match_call_path(&call_path, module, member, from_imports)
+            })
+        })
+    {
+        FunctionType::ClassMethod
+    } else if decorator_list.iter().any(|expr| {
+        // The method is decorated with a static method decorator (like
+        // `@staticmethod`).
+        let call_path = dealias_call_path(collect_call_paths(expr), import_aliases);
+        staticmethod_decorators.iter().any(|decorator| {
+            let (module, member) = to_module_and_member(decorator);
+            match_call_path(&call_path, module, member, from_imports)
+        })
+    }) {
+        FunctionType::StaticMethod
+    } else {
+        // It's an instance method.
+        FunctionType::Method
+    }
+}

src/ast/helpers.rs

@@ -1,13 +1,26 @@
+use log::error;
 use once_cell::sync::Lazy;
 use regex::Regex;
 use rustc_hash::{FxHashMap, FxHashSet};
 use rustpython_ast::{
-    Arguments, Excepthandler, ExcepthandlerKind, Expr, ExprKind, Location, Stmt, StmtKind,
+    Arguments, Constant, Excepthandler, ExcepthandlerKind, Expr, ExprKind, Location, Stmt, StmtKind,
 };
+use rustpython_parser::lexer;
+use rustpython_parser::lexer::Tok;
 
 use crate::ast::types::Range;
 use crate::SourceCodeLocator;
 
+/// Create an `Expr` with default location from an `ExprKind`.
+pub fn create_expr(node: ExprKind) -> Expr {
+    Expr::new(Location::default(), Location::default(), node)
+}
+
+/// Create a `Stmt` with a default location from a `StmtKind`.
+pub fn create_stmt(node: StmtKind) -> Stmt {
+    Stmt::new(Location::default(), Location::default(), node)
+}
+
 fn collect_call_path_inner<'a>(expr: &'a Expr, parts: &mut Vec<&'a str>) {
     match &expr.node {
         ExprKind::Call { func, .. } => {
@@ -149,15 +162,12 @@ pub fn match_call_path(
 
 static DUNDER_REGEX: Lazy<Regex> = Lazy::new(|| Regex::new(r"__[^\s]+__").unwrap());
 
-pub fn is_assignment_to_a_dunder(node: &StmtKind) -> bool {
+/// Return `true` if the `Stmt` is an assignment to a dunder (like `__all__`).
+pub fn is_assignment_to_a_dunder(stmt: &Stmt) -> 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.
-    match node {
-        StmtKind::Assign {
-            targets,
-            value: _,
-            type_comment: _,
-        } => {
+    match &stmt.node {
+        StmtKind::Assign { targets, .. } => {
             if targets.len() != 1 {
                 return false;
             }
@@ -166,12 +176,7 @@ pub fn is_assignment_to_a_dunder(node: &StmtKind) -> bool {
                 _ => false,
             }
         }
-        StmtKind::AnnAssign {
-            target,
-            annotation: _,
-            value: _,
-            simple: _,
-        } => match &target.node {
+        StmtKind::AnnAssign { target, .. } => match &target.node {
             ExprKind::Name { id, ctx: _ } => DUNDER_REGEX.is_match(id),
             _ => false,
         },
@@ -179,6 +184,32 @@ pub fn is_assignment_to_a_dunder(node: &StmtKind) -> bool {
     }
 }
 
+/// Return `true` if the `Expr` is a singleton (`None`, `True`, `False`, or
+/// `...`).
+pub fn is_singleton(expr: &Expr) -> bool {
+    matches!(
+        expr.node,
+        ExprKind::Constant {
+            value: Constant::None | Constant::Bool(_) | Constant::Ellipsis,
+            ..
+        }
+    )
+}
+
+/// Return `true` if the `Expr` is a constant or tuple of constants.
+pub fn is_constant(expr: &Expr) -> bool {
+    match &expr.node {
+        ExprKind::Constant { .. } => true,
+        ExprKind::Tuple { elts, .. } => elts.iter().all(is_constant),
+        _ => false,
+    }
+}
+
+/// Return `true` if the `Expr` is a non-singleton constant.
+pub fn is_constant_non_singleton(expr: &Expr) -> bool {
+    is_constant(expr) && !is_singleton(expr)
+}
+
 /// Extract the names of all handled exceptions.
 pub fn extract_handler_names(handlers: &[Excepthandler]) -> Vec<Vec<&str>> {
     let mut handler_names = vec![];
@@ -229,7 +260,6 @@ pub fn collect_arg_names<'a>(arguments: &'a Arguments) -> FxHashSet<&'a str> {
 
 /// Returns `true` if a call is an argumented `super` invocation.
 pub fn is_super_call_with_arguments(func: &Expr, args: &[Expr]) -> bool {
-    // Check: is this a `super` call?
     if let ExprKind::Name { id, .. } = &func.node {
         id == "super" && !args.is_empty()
     } else {
@@ -311,13 +341,75 @@ pub fn count_trailing_lines(stmt: &Stmt, locator: &SourceCodeLocator) -> usize {
         .count()
 }
 
+/// Return the appropriate visual `Range` for any message that spans a `Stmt`.
+/// Specifically, this method returns the range of a function or class name,
+/// rather than that of the entire function or class body.
+pub fn identifier_range(stmt: &Stmt, locator: &SourceCodeLocator) -> Range {
+    if matches!(
+        stmt.node,
+        StmtKind::ClassDef { .. }
+            | StmtKind::FunctionDef { .. }
+            | StmtKind::AsyncFunctionDef { .. }
+    ) {
+        let contents = locator.slice_source_code_range(&Range::from_located(stmt));
+        for (start, tok, end) in lexer::make_tokenizer(&contents).flatten() {
+            if matches!(tok, Tok::Name { .. }) {
+                let start = to_absolute(start, stmt.location);
+                let end = to_absolute(end, stmt.location);
+                return Range {
+                    location: start,
+                    end_location: end,
+                };
+            }
+        }
+        error!("Failed to find identifier for {:?}", stmt);
+    }
+    Range::from_located(stmt)
+}
+
+/// Return `true` if a `Stmt` appears to be part of a multi-statement line, with
+/// other statements preceding it.
+pub fn preceded_by_continuation(stmt: &Stmt, locator: &SourceCodeLocator) -> bool {
+    // Does the previous line end in a continuation? This will have a specific
+    // false-positive, which is that if the previous line ends in a comment, it
+    // will be treated as a continuation. So we should only use this information to
+    // make conservative choices.
+    // TODO(charlie): Come up with a more robust strategy.
+    if stmt.location.row() > 1 {
+        let range = Range {
+            location: Location::new(stmt.location.row() - 1, 0),
+            end_location: Location::new(stmt.location.row(), 0),
+        };
+        let line = locator.slice_source_code_range(&range);
+        if line.trim().ends_with('\\') {
+            return true;
+        }
+    }
+    false
+}
+
+/// Return `true` if a `Stmt` appears to be part of a multi-statement line, with
+/// other statements preceding it.
+pub fn preceded_by_multi_statement_line(stmt: &Stmt, locator: &SourceCodeLocator) -> bool {
+    match_leading_content(stmt, locator) || preceded_by_continuation(stmt, locator)
+}
+
+/// Return `true` if a `Stmt` appears to be part of a multi-statement line, with
+/// other statements following it.
+pub fn followed_by_multi_statement_line(stmt: &Stmt, locator: &SourceCodeLocator) -> bool {
+    match_trailing_content(stmt, locator)
+}
+
 #[cfg(test)]
 mod tests {
     use anyhow::Result;
     use rustc_hash::{FxHashMap, FxHashSet};
+    use rustpython_ast::Location;
     use rustpython_parser::parser;
 
-    use crate::ast::helpers::match_module_member;
+    use crate::ast::helpers::{identifier_range, match_module_member, match_trailing_content};
+    use crate::ast::types::Range;
+    use crate::source_code_locator::SourceCodeLocator;
 
     #[test]
     fn builtin() -> Result<()> {
@@ -461,4 +553,130 @@ mod tests {
         ));
         Ok(())
     }
+
+    #[test]
+    fn trailing_content() -> Result<()> {
+        let contents = "x = 1";
+        let program = parser::parse_program(contents, "<filename>")?;
+        let stmt = program.first().unwrap();
+        let locator = SourceCodeLocator::new(contents);
+        assert!(!match_trailing_content(stmt, &locator));
+
+        let contents = "x = 1; y = 2";
+        let program = parser::parse_program(contents, "<filename>")?;
+        let stmt = program.first().unwrap();
+        let locator = SourceCodeLocator::new(contents);
+        assert!(match_trailing_content(stmt, &locator));
+
+        let contents = "x = 1  ";
+        let program = parser::parse_program(contents, "<filename>")?;
+        let stmt = program.first().unwrap();
+        let locator = SourceCodeLocator::new(contents);
+        assert!(!match_trailing_content(stmt, &locator));
+
+        let contents = "x = 1  # Comment";
+        let program = parser::parse_program(contents, "<filename>")?;
+        let stmt = program.first().unwrap();
+        let locator = SourceCodeLocator::new(contents);
+        assert!(!match_trailing_content(stmt, &locator));
+
+        let contents = r#"
+x = 1
+y = 2
+"#
+        .trim();
+        let program = parser::parse_program(contents, "<filename>")?;
+        let stmt = program.first().unwrap();
+        let locator = SourceCodeLocator::new(contents);
+        assert!(!match_trailing_content(stmt, &locator));
+
+        Ok(())
+    }
+
+    #[test]
+    fn extract_identifier_range() -> Result<()> {
+        let contents = "def f(): pass".trim();
+        let program = parser::parse_program(contents, "<filename>")?;
+        let stmt = program.first().unwrap();
+        let locator = SourceCodeLocator::new(contents);
+        assert_eq!(
+            identifier_range(stmt, &locator),
+            Range {
+                location: Location::new(1, 4),
+                end_location: Location::new(1, 5),
+            }
+        );
+
+        let contents = r#"
+def \
+  f():
+  pass
+"#
+        .trim();
+        let program = parser::parse_program(contents, "<filename>")?;
+        let stmt = program.first().unwrap();
+        let locator = SourceCodeLocator::new(contents);
+        assert_eq!(
+            identifier_range(stmt, &locator),
+            Range {
+                location: Location::new(2, 2),
+                end_location: Location::new(2, 3),
+            }
+        );
+
+        let contents = "class Class(): pass".trim();
+        let program = parser::parse_program(contents, "<filename>")?;
+        let stmt = program.first().unwrap();
+        let locator = SourceCodeLocator::new(contents);
+        assert_eq!(
+            identifier_range(stmt, &locator),
+            Range {
+                location: Location::new(1, 6),
+                end_location: Location::new(1, 11),
+            }
+        );
+
+        let contents = "class Class: pass".trim();
+        let program = parser::parse_program(contents, "<filename>")?;
+        let stmt = program.first().unwrap();
+        let locator = SourceCodeLocator::new(contents);
+        assert_eq!(
+            identifier_range(stmt, &locator),
+            Range {
+                location: Location::new(1, 6),
+                end_location: Location::new(1, 11),
+            }
+        );
+
+        let contents = r#"
+@decorator()
+class Class():
+  pass
+"#
+        .trim();
+        let program = parser::parse_program(contents, "<filename>")?;
+        let stmt = program.first().unwrap();
+        let locator = SourceCodeLocator::new(contents);
+        assert_eq!(
+            identifier_range(stmt, &locator),
+            Range {
+                location: Location::new(2, 6),
+                end_location: Location::new(2, 11),
+            }
+        );
+
+        let contents = r#"x = y + 1"#.trim();
+        let program = parser::parse_program(contents, "<filename>")?;
+        let stmt = program.first().unwrap();
+        let locator = SourceCodeLocator::new(contents);
+        assert_eq!(
+            identifier_range(stmt, &locator),
+            Range {
+                location: Location::new(1, 0),
+                end_location: Location::new(1, 9),
+            }
+        );
+
+        Ok(())
+    }
 }

src/ast/mod.rs

@@ -1,3 +1,6 @@
+pub mod branch_detection;
+pub mod cast;
+pub mod function_type;
 pub mod helpers;
 pub mod operations;
 pub mod relocate;

src/ast/operations.rs

@@ -1,12 +1,15 @@
+use rustc_hash::FxHashMap;
 use rustpython_ast::{Cmpop, Located};
 use rustpython_parser::ast::{Constant, Expr, ExprKind, Stmt, StmtKind};
 use rustpython_parser::lexer;
 use rustpython_parser::lexer::Tok;
 
-use crate::ast::types::{BindingKind, Scope};
+use crate::ast::types::{Binding, BindingKind, Scope};
+use crate::ast::visitor;
+use crate::ast::visitor::Visitor;
 
 /// Extract the names bound to a given __all__ assignment.
-pub fn extract_all_names(stmt: &Stmt, scope: &Scope) -> Vec<String> {
+pub fn extract_all_names(stmt: &Stmt, scope: &Scope, bindings: &[Binding]) -> Vec<String> {
     fn add_to_names(names: &mut Vec<String>, elts: &[Expr]) {
         for elt in elts {
             if let ExprKind::Constant {
@@ -23,8 +26,8 @@ pub fn extract_all_names(stmt: &Stmt, scope: &Scope) -> Vec<String> {
 
     // Grab the existing bound __all__ values.
     if let StmtKind::AugAssign { .. } = &stmt.node {
-        if let Some(binding) = scope.values.get("__all__") {
-            if let BindingKind::Export(existing) = &binding.kind {
+        if let Some(index) = scope.values.get("__all__") {
+            if let BindingKind::Export(existing) = &bindings[*index].kind {
                 names.extend_from_slice(existing);
             }
         }
@@ -69,6 +72,38 @@ pub fn extract_all_names(stmt: &Stmt, scope: &Scope) -> Vec<String> {
     names
 }
 
+#[derive(Default)]
+struct GlobalVisitor<'a> {
+    globals: FxHashMap<&'a str, &'a Stmt>,
+}
+
+impl<'a> Visitor<'a> for GlobalVisitor<'a> {
+    fn visit_stmt(&mut self, stmt: &'a Stmt) {
+        match &stmt.node {
+            StmtKind::Global { names } => {
+                for name in names {
+                    self.globals.insert(name, stmt);
+                }
+            }
+            StmtKind::FunctionDef { .. }
+            | StmtKind::AsyncFunctionDef { .. }
+            | StmtKind::ClassDef { .. } => {
+                // Don't recurse.
+            }
+            _ => visitor::walk_stmt(self, stmt),
+        }
+    }
+}
+
+/// Extract a map from global name to its last-defining `Stmt`.
+pub fn extract_globals(body: &[Stmt]) -> FxHashMap<&str, &Stmt> {
+    let mut visitor = GlobalVisitor::default();
+    for stmt in body {
+        visitor.visit_stmt(stmt);
+    }
+    visitor.globals
+}
+
 /// Check if a node is parent of a conditional branch.
 pub fn on_conditional_branch<'a>(parents: &mut impl Iterator<Item = &'a Stmt>) -> bool {
     parents.any(|parent| {

src/ast/types.rs

@@ -1,7 +1,7 @@
 use std::sync::atomic::{AtomicUsize, Ordering};
 
 use rustc_hash::FxHashMap;
-use rustpython_ast::{Expr, Keyword, Stmt};
+use rustpython_ast::{Arguments, Expr, Keyword, Stmt};
 use rustpython_parser::ast::{Located, Location};
 
 fn id() -> usize {
@@ -30,36 +30,60 @@ impl Range {
     }
 }
 
-#[derive(Clone, Debug)]
-pub struct FunctionScope {
+#[derive(Debug)]
+pub struct FunctionDef<'a> {
+    // Properties derived from StmtKind::FunctionDef.
+    pub name: &'a str,
+    pub args: &'a Arguments,
+    pub body: &'a [Stmt],
+    pub decorator_list: &'a [Expr],
+    // pub returns: Option<&'a Expr>,
+    // pub type_comment: Option<&'a str>,
+    // Scope-specific properties.
+    // TODO(charlie): Create AsyncFunctionDef to mirror the AST.
     pub async_: bool,
-    pub uses_locals: bool,
+    pub globals: FxHashMap<&'a str, &'a Stmt>,
 }
 
-#[derive(Clone, Debug)]
-pub struct ClassScope<'a> {
+#[derive(Debug)]
+pub struct ClassDef<'a> {
+    // Properties derived from StmtKind::ClassDef.
     pub name: &'a str,
     pub bases: &'a [Expr],
     pub keywords: &'a [Keyword],
+    // pub body: &'a [Stmt],
     pub decorator_list: &'a [Expr],
+    // Scope-specific properties.
+    pub globals: FxHashMap<&'a str, &'a Stmt>,
 }
 
-#[derive(Clone, Debug)]
+#[derive(Debug)]
+pub struct Lambda<'a> {
+    pub args: &'a Arguments,
+    pub body: &'a Expr,
+}
+
+#[derive(Debug)]
 pub enum ScopeKind<'a> {
-    Class(ClassScope<'a>),
-    Function(FunctionScope),
+    Class(ClassDef<'a>),
+    Function(FunctionDef<'a>),
     Generator,
     Module,
     Arg,
-    Lambda,
+    Lambda(Lambda<'a>),
 }
 
-#[derive(Clone, Debug)]
+#[derive(Debug)]
 pub struct Scope<'a> {
     pub id: usize,
     pub kind: ScopeKind<'a>,
     pub import_starred: bool,
-    pub values: FxHashMap<&'a str, Binding>,
+    pub uses_locals: bool,
+    /// A map from bound name to binding index.
+    pub values: FxHashMap<&'a str, usize>,
+    /// A list of (name, index) pairs for bindings that were overridden in the
+    /// scope.
+    pub overridden: Vec<(&'a str, usize)>,
 }
 
 impl<'a> Scope<'a> {
@@ -68,43 +92,122 @@ impl<'a> Scope<'a> {
             id: id(),
             kind,
             import_starred: false,
+            uses_locals: false,
             values: FxHashMap::default(),
+            overridden: Vec::new(),
         }
     }
 }
 
-#[derive(Clone, Debug)]
-pub struct BindingContext {
-    pub defined_by: usize,
-    pub defined_in: Option<usize>,
-}
-
 #[derive(Clone, Debug)]
 pub enum BindingKind {
     Annotation,
     Argument,
     Assignment,
-    // TODO(charlie): This seems to be a catch-all.
     Binding,
     LoopVar,
     Global,
     Nonlocal,
     Builtin,
     ClassDefinition,
-    Definition,
+    FunctionDefinition,
     Export(Vec<String>),
     FutureImportation,
     StarImportation(Option<usize>, Option<String>),
-    Importation(String, String, BindingContext),
-    FromImportation(String, String, BindingContext),
-    SubmoduleImportation(String, String, BindingContext),
+    Importation(String, String),
+    FromImportation(String, String),
+    SubmoduleImportation(String, String),
 }
 
 #[derive(Clone, Debug)]
-pub struct Binding {
+pub struct Binding<'a> {
     pub kind: BindingKind,
     pub range: Range,
+    /// The statement in which the `Binding` was defined.
+    pub source: Option<RefEquality<'a, Stmt>>,
     /// Tuple of (scope index, range) indicating the scope and range at which
     /// the binding was last used.
     pub used: Option<(usize, Range)>,
 }
+
+// Pyflakes defines the following binding hierarchy (via inheritance):
+//   Binding
+//    ExportBinding
+//    Annotation
+//    Argument
+//    Assignment
+//      NamedExprAssignment
+//    Definition
+//      FunctionDefinition
+//      ClassDefinition
+//      Builtin
+//      Importation
+//        SubmoduleImportation
+//        ImportationFrom
+//        StarImportation
+//        FutureImportation
+
+impl<'a> Binding<'a> {
+    pub fn is_definition(&self) -> bool {
+        matches!(
+            self.kind,
+            BindingKind::ClassDefinition
+                | BindingKind::FunctionDefinition
+                | BindingKind::Builtin
+                | BindingKind::FutureImportation
+                | BindingKind::StarImportation(..)
+                | BindingKind::Importation(..)
+                | BindingKind::FromImportation(..)
+                | BindingKind::SubmoduleImportation(..)
+        )
+    }
+
+    pub fn redefines(&self, existing: &'a Binding) -> bool {
+        match &self.kind {
+            BindingKind::Importation(_, full_name) | BindingKind::FromImportation(_, full_name) => {
+                if let BindingKind::SubmoduleImportation(_, existing_full_name) = &existing.kind {
+                    return full_name == existing_full_name;
+                }
+            }
+            BindingKind::SubmoduleImportation(_, full_name) => {
+                if let BindingKind::Importation(_, existing_full_name)
+                | BindingKind::FromImportation(_, existing_full_name)
+                | BindingKind::SubmoduleImportation(_, existing_full_name) = &existing.kind
+                {
+                    return full_name == existing_full_name;
+                }
+            }
+            BindingKind::Annotation => {
+                return false;
+            }
+            BindingKind::FutureImportation => {
+                return false;
+            }
+            BindingKind::StarImportation(..) => {
+                return false;
+            }
+            _ => {}
+        }
+        existing.is_definition()
+    }
+}
+
+#[derive(Debug, Copy, Clone)]
+pub struct RefEquality<'a, T>(pub &'a T);
+
+impl<'a, T> std::hash::Hash for RefEquality<'a, T> {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: std::hash::Hasher,
+    {
+        (self.0 as *const T).hash(state);
+    }
+}
+
+impl<'a, 'b, T> PartialEq<RefEquality<'b, T>> for RefEquality<'a, T> {
+    fn eq(&self, other: &RefEquality<'b, T>) -> bool {
+        std::ptr::eq(self.0, other.0)
+    }
+}
+
+impl<'a, T> Eq for RefEquality<'a, T> {}

src/ast/visitor.rs

@@ -159,8 +159,8 @@ pub fn walk_stmt<'a, V: Visitor<'a> + ?Sized>(visitor: &mut V, stmt: &'a Stmt) {
             orelse,
             ..
         } => {
-            visitor.visit_expr(target);
             visitor.visit_expr(iter);
+            visitor.visit_expr(target);
             for stmt in body {
                 visitor.visit_stmt(stmt);
             }
@@ -175,8 +175,8 @@ pub fn walk_stmt<'a, V: Visitor<'a> + ?Sized>(visitor: &mut V, stmt: &'a Stmt) {
             orelse,
             ..
         } => {
-            visitor.visit_expr(target);
             visitor.visit_expr(iter);
+            visitor.visit_expr(target);
             for stmt in body {
                 visitor.visit_stmt(stmt);
             }

src/ast/whitespace.rs

@@ -1,3 +1,4 @@
+use std::borrow::Cow;
 use std::str::Lines;
 
 use rustpython_ast::{Located, Location};
@@ -5,31 +6,26 @@ use rustpython_ast::{Located, Location};
 use crate::ast::types::Range;
 use crate::check_ast::Checker;
 
+/// Extract the leading indentation from a line.
+pub fn indentation<'a, T>(checker: &'a Checker, located: &'a Located<T>) -> Cow<'a, str> {
+    let range = Range::from_located(located);
+    checker.locator.slice_source_code_range(&Range {
+        location: Location::new(range.location.row(), 0),
+        end_location: Location::new(range.location.row(), range.location.column()),
+    })
+}
+
 /// Extract the leading words from a line of text.
-pub fn leading_words(line: &str) -> String {
-    line.trim()
-        .chars()
-        .take_while(|char| char.is_alphanumeric() || char.is_whitespace())
-        .collect()
+pub fn leading_words(line: &str) -> &str {
+    let line = line.trim();
+    line.find(|char: char| !char.is_alphanumeric() && !char.is_whitespace())
+        .map_or(line, |index| &line[..index])
 }
 
 /// Extract the leading whitespace from a line of text.
-pub fn leading_space(line: &str) -> String {
-    line.chars()
-        .take_while(|char| char.is_whitespace())
-        .collect()
-}
-
-/// Extract the leading indentation from a line.
-pub fn indentation<T>(checker: &Checker, located: &Located<T>) -> String {
-    let range = Range::from_located(located);
-    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()
+pub fn leading_space(line: &str) -> &str {
+    line.find(|char: char| !char.is_whitespace())
+        .map_or(line, |index| &line[..index])
 }
 
 /// Replace any non-whitespace characters from an indentation string.

src/autofix/fixer.rs

@@ -10,7 +10,7 @@ use crate::autofix::Fix;
 use crate::checks::Check;
 use crate::source_code_locator::SourceCodeLocator;
 
-#[derive(Hash)]
+#[derive(Debug, Hash)]
 pub enum Mode {
     Generate,
     Apply,

src/autofix/helpers.rs

@@ -2,7 +2,11 @@ use anyhow::{bail, Result};
 use itertools::Itertools;
 use rustpython_parser::ast::{ExcepthandlerKind, Location, Stmt, StmtKind};
 
+use crate::ast::helpers;
+use crate::ast::helpers::to_absolute;
+use crate::ast::whitespace::LinesWithTrailingNewline;
 use crate::autofix::Fix;
+use crate::source_code_locator::SourceCodeLocator;
 
 /// Determine if a body contains only a single statement, taking into account
 /// deleted.
@@ -66,7 +70,87 @@ fn is_lone_child(child: &Stmt, parent: &Stmt, deleted: &[&Stmt]) -> Result<bool>
     }
 }
 
-pub fn remove_stmt(stmt: &Stmt, parent: Option<&Stmt>, deleted: &[&Stmt]) -> Result<Fix> {
+/// Return the location of a trailing semicolon following a `Stmt`, if it's part
+/// of a multi-statement line.
+fn trailing_semicolon(stmt: &Stmt, locator: &SourceCodeLocator) -> Option<Location> {
+    let contents = locator.slice_source_code_at(&stmt.end_location.unwrap());
+    for (row, line) in LinesWithTrailingNewline::from(&contents).enumerate() {
+        let trimmed = line.trim();
+        if trimmed.starts_with(';') {
+            let column = line
+                .char_indices()
+                .find_map(|(column, char)| if char == ';' { Some(column) } else { None })
+                .unwrap();
+            return Some(to_absolute(
+                Location::new(row + 1, column),
+                stmt.end_location.unwrap(),
+            ));
+        }
+        if !trimmed.starts_with('\\') {
+            break;
+        }
+    }
+    None
+}
+
+/// Find the next valid break for a `Stmt` after a semicolon.
+fn next_stmt_break(semicolon: Location, locator: &SourceCodeLocator) -> Location {
+    let start_location = Location::new(semicolon.row(), semicolon.column() + 1);
+    let contents = locator.slice_source_code_at(&start_location);
+    for (row, line) in LinesWithTrailingNewline::from(&contents).enumerate() {
+        let trimmed = line.trim();
+        // Skip past any continuations.
+        if trimmed.starts_with('\\') {
+            continue;
+        }
+        return if trimmed.is_empty() {
+            // If the line is empty, then despite the previous statement ending in a
+            // semicolon, we know that it's not a multi-statement line.
+            to_absolute(Location::new(row + 1, 0), start_location)
+        } else {
+            // Otherwise, find the start of the next statement. (Or, anything that isn't
+            // whitespace.)
+            let column = line
+                .char_indices()
+                .find_map(|(column, char)| {
+                    if char.is_whitespace() {
+                        None
+                    } else {
+                        Some(column)
+                    }
+                })
+                .unwrap();
+            to_absolute(Location::new(row + 1, column), start_location)
+        };
+    }
+    Location::new(start_location.row() + 1, 0)
+}
+
+/// Return `true` if a `Stmt` occurs at the end of a file.
+fn is_end_of_file(stmt: &Stmt, locator: &SourceCodeLocator) -> bool {
+    let contents = locator.slice_source_code_at(&stmt.end_location.unwrap());
+    contents.is_empty()
+}
+
+/// Return the `Fix` to use when deleting a `Stmt`.
+///
+/// In some cases, this is as simple as deleting the `Range` of the `Stmt`
+/// itself. However, there are a few exceptions:
+/// - If the `Stmt` is _not_ the terminal statement in a multi-statement line,
+///   we need to delete up to the start of the next statement (and avoid
+///   deleting any content that precedes the statement).
+/// - If the `Stmt` is the terminal statement in a multi-statement line, we need
+///   to avoid deleting any content that precedes the statement.
+/// - If the `Stmt` has no trailing and leading content, then it's convenient to
+///   remove the entire start and end lines.
+/// - If the `Stmt` is the last statement in its parent body, replace it with a
+///   `pass` instead.
+pub fn delete_stmt(
+    stmt: &Stmt,
+    parent: Option<&Stmt>,
+    deleted: &[&Stmt],
+    locator: &SourceCodeLocator,
+) -> Result<Fix> {
     if parent
         .map(|parent| is_lone_child(stmt, parent, deleted))
         .map_or(Ok(None), |v| v.map(Some))?
@@ -80,12 +164,103 @@ pub fn remove_stmt(stmt: &Stmt, parent: Option<&Stmt>, deleted: &[&Stmt]) -> Res
             stmt.end_location.unwrap(),
         ))
     } else {
-        // Otherwise, nuke the entire line.
-        // TODO(charlie): This logic assumes that there are no multi-statement physical
-        // lines.
-        Ok(Fix::deletion(
-            Location::new(stmt.location.row(), 0),
-            Location::new(stmt.end_location.unwrap().row() + 1, 0),
-        ))
+        Ok(if let Some(semicolon) = trailing_semicolon(stmt, locator) {
+            let next = next_stmt_break(semicolon, locator);
+            Fix::deletion(stmt.location, next)
+        } else if helpers::match_leading_content(stmt, locator) {
+            Fix::deletion(stmt.location, stmt.end_location.unwrap())
+        } else if helpers::preceded_by_continuation(stmt, locator) {
+            if is_end_of_file(stmt, locator) && stmt.location.column() == 0 {
+                // Special-case: a file can't end in a continuation.
+                Fix::replacement("\n".to_string(), stmt.location, stmt.end_location.unwrap())
+            } else {
+                Fix::deletion(stmt.location, stmt.end_location.unwrap())
+            }
+        } else {
+            Fix::deletion(
+                Location::new(stmt.location.row(), 0),
+                Location::new(stmt.end_location.unwrap().row() + 1, 0),
+            )
+        })
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use anyhow::Result;
+    use rustpython_ast::Location;
+    use rustpython_parser::parser;
+
+    use crate::autofix::helpers::{next_stmt_break, trailing_semicolon};
+    use crate::source_code_locator::SourceCodeLocator;
+
+    #[test]
+    fn find_semicolon() -> Result<()> {
+        let contents = "x = 1";
+        let program = parser::parse_program(contents, "<filename>")?;
+        let stmt = program.first().unwrap();
+        let locator = SourceCodeLocator::new(contents);
+        assert_eq!(trailing_semicolon(stmt, &locator), None);
+
+        let contents = "x = 1; y = 1";
+        let program = parser::parse_program(contents, "<filename>")?;
+        let stmt = program.first().unwrap();
+        let locator = SourceCodeLocator::new(contents);
+        assert_eq!(
+            trailing_semicolon(stmt, &locator),
+            Some(Location::new(1, 5))
+        );
+
+        let contents = "x = 1 ; y = 1";
+        let program = parser::parse_program(contents, "<filename>")?;
+        let stmt = program.first().unwrap();
+        let locator = SourceCodeLocator::new(contents);
+        assert_eq!(
+            trailing_semicolon(stmt, &locator),
+            Some(Location::new(1, 6))
+        );
+
+        let contents = r#"
+x = 1 \
+  ; y = 1
+"#
+        .trim();
+        let program = parser::parse_program(contents, "<filename>")?;
+        let stmt = program.first().unwrap();
+        let locator = SourceCodeLocator::new(contents);
+        assert_eq!(
+            trailing_semicolon(stmt, &locator),
+            Some(Location::new(2, 2))
+        );
+
+        Ok(())
+    }
+
+    #[test]
+    fn find_next_stmt_break() {
+        let contents = "x = 1; y = 1";
+        let locator = SourceCodeLocator::new(contents);
+        assert_eq!(
+            next_stmt_break(Location::new(1, 4), &locator),
+            Location::new(1, 5)
+        );
+
+        let contents = "x = 1 ; y = 1";
+        let locator = SourceCodeLocator::new(contents);
+        assert_eq!(
+            next_stmt_break(Location::new(1, 5), &locator),
+            Location::new(1, 6)
+        );
+
+        let contents = r#"
+x = 1 \
+  ; y = 1
+"#
+        .trim();
+        let locator = SourceCodeLocator::new(contents);
+        assert_eq!(
+            next_stmt_break(Location::new(2, 2), &locator),
+            Location::new(2, 4)
+        );
     }
 }