Compile for WASM

- wasm-pack build --target web
- rm -rf demo/src/pkg && cp -r pkg demo/src/pkg
- npm run dev

.pre-commit-config.yaml

@@ -1,5 +1,5 @@
 repos:
-  - repo: https://github.com/charliermarsh/ruff
+  - repo: https://github.com/charliermarsh/ruff-pre-commit
     rev: v0.0.40
     hooks:
       - id: lint

.pre-commit-hooks.yaml

@@ -1,7 +0,0 @@
-- id: lint
-  name: ruff lint
-  description: Run ruff to lint Python files.
-  entry: ruff
-  language: python
-  types_or: [python]
-  pass_filenames: true

Cargo.toml

@@ -1,45 +1,32 @@
 [package]
 name = "ruff"
-version = "0.0.40"
+version = "0.0.44"
 edition = "2021"
 
 [lib]
 name = "ruff"
+crate-type = ["cdylib"]
 
 [dependencies]
+wasm-bindgen = "0.2.83"
 anyhow = { version = "1.0.60" }
-bincode = { version = "1.3.3" }
-cacache = { version = "10.0.1" }
 chrono = { version = "0.4.21" }
-clap = { version = "3.2.16", features = ["derive"] }
-clearscreen = { version = "1.0.10" }
-colored = { version = "2.0.0" }
-common-path = { version = "1.0.0" }
-dirs = { version = "4.0.0" }
 fern = { version = "0.6.1" }
 filetime = { version = "0.2.17" }
-glob = "0.3.0"
-itertools = "0.10.3"
+glob = { version = "0.3.0" }
+itertools = { version = "0.10.3" }
 log = { version = "0.4.17" }
-notify = { version = "4.0.17" }
 once_cell = { version = "1.13.1" }
-path-absolutize = "3.0.13"
 rayon = { version = "1.5.3" }
 regex = { version = "1.6.0" }
 rustpython-parser = { features = ["lalrpop"], git = "https://github.com/charliermarsh/RustPython.git", rev = "7d21c6923a506e79cc041708d83cef925efd33f4" }
 serde = { version = "1.0.143", features = ["derive"] }
 serde_json = { version = "1.0.83" }
 toml = { version = "0.5.9" }
-update-informer = { version = "0.5.0", default_features = false, features = ["pypi"], optional = true }
-walkdir = { version = "2.3.2" }
 
 [dev-dependencies]
 insta = { version = "1.19.1", features = ["yaml"] }
 
-[features]
-default = ["update-informer"]
-update-informer = ["dep:update-informer"]
-
 [profile.release]
 panic = "abort"
 lto = "thin"

README.md

@@ -1,7 +1,9 @@
 # ruff
 
+[![image](https://img.shields.io/pypi/v/ruff.svg)](https://pypi.python.org/pypi/ruff)
+[![image](https://img.shields.io/pypi/l/ruff.svg)](https://pypi.python.org/pypi/ruff)
+[![image](https://img.shields.io/pypi/pyversions/ruff.svg)](https://pypi.python.org/pypi/ruff)
 [![Actions status](https://github.com/charliermarsh/ruff/workflows/CI/badge.svg)](https://github.com/charliermarsh/ruff/actions)
-[![PyPI version](https://badge.fury.io/py/ruff.svg)](https://badge.fury.io/py/ruff)
 
 An extremely fast Python linter, written in Rust.
 
@@ -20,9 +22,7 @@ An extremely fast Python linter, written in Rust.
 - 📦 [ESLint](https://eslint.org/docs/latest/user-guide/command-line-interface#caching)-inspired cache support
 - 🔧 [ESLint](https://eslint.org/docs/latest/user-guide/command-line-interface#caching)-inspired `--fix` support
 - 👀 [TypeScript](https://www.typescriptlang.org/docs/handbook/configuring-watch.html)-inspired `--watch` support
-
-_ruff is a proof-of-concept and not yet intended for production use. It supports only a small subset
-of the Flake8 rules, and may crash on your codebase._
+- ⚖️ [Near-complete parity](#Parity-with-Flake8) with the built-in Flake8 rule set
 
 Read the [launch blog post](https://notes.crmarsh.com/python-tooling-could-be-much-much-faster).
 
@@ -52,14 +52,14 @@ You can run ruff in `--watch` mode to automatically re-run on-change:
 ruff path/to/code/ --watch
 ```
 
-ruff also works with [Pre-Commit](https://pre-commit.com) (requires Cargo on system):
+ruff also works with [pre-commit](https://pre-commit.com):
 
 ```yaml
 repos:
-- repo: https://github.com/charliermarsh/ruff
-  rev: v0.0.40
-  hooks:
-    - id: lint
+  - repo: https://github.com/charliermarsh/ruff-pre-commit
+    rev: v0.0.40
+    hooks:
+      - id: lint
 ```
 
 ## Configuration
@@ -86,7 +86,7 @@ ruff path/to/code/ --select F401 F403
 See `ruff --help` for more:
 
 ```shell
-ruff (v0.0.40)
+ruff (v0.0.44) 0.0.44
 An extremely fast Python linter.
 
 USAGE:
@@ -117,8 +117,14 @@ OPTIONS:
             Disable all logging (but still exit with status code "1" upon detecting errors)
         --select <SELECT>...
             List of error codes to enable
+        --show-files
+            See the files ruff will be run against with the current configuration options
+        --show-settings
+            See ruff's settings
     -v, --verbose
             Enable verbose logging
+    -V, --version
+            Print version information
     -w, --watch
             Run in watch mode by re-running whenever files change
 ```
@@ -128,38 +134,31 @@ Exclusions are based on globs, and can be either:
 - Single-path patterns, like `.mypy_cache` (to exclude any directory named `.mypy_cache` in the
   tree), `foo.py` (to exclude any file named `foo.py`), or `foo_*.py` (to exclude any file matching
   `foo_*.py` ).
-- Relative patterns, like `./directory/foo.py` (to exclude that specific file) or `./directory/*.py`
-  (to exclude any Python files in `./directory`). Note that these paths are relative to the
-  directory from which you execute `ruff`, and _not_ the directory of the `pyproject.toml`.
+- Relative patterns, like `directory/foo.py` (to exclude that specific file) or `directory/*.py`
+  (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`).
 
 ### Compatibility with Black
 
-ruff is intended to be compatible with [Black](https://github.com/psf/black), and should be
-compatible out-of-the-box as long as the `line-length` setting is consistent between the two.
+ruff is compatible with [Black](https://github.com/psf/black) out-of-the-box, as long as
+the `line-length` setting is consistent between the two.
 
 As a project, ruff is designed to be used alongside Black and, as such, will defer implementing
-lint rules that are obviated by Black (e.g., stylistic rules).
+stylistic lint rules that are obviated by autoformatting.
 
 ### Parity with Flake8
 
-ruff's goal is to achieve feature-parity with Flake8 when used (1) without any plugins,
-(2) alongside Black, and (3) on Python 3 code. (Using Black obviates the need for many of Flake8's
-stylistic checks; limiting to Python 3 obviates the need for certain compatibility checks.)
+ruff's goal is to achieve feature-parity with Flake8 when used (1) without plugins, (2) alongside
+Black, and (3) on Python 3 code.
 
-Under those conditions, Flake8 implements about 60 rules, give or take. At time of writing, ruff
-implements 42 rules. (Note that these 42 rules likely cover a disproportionate share of errors:
-unused imports, undefined variables, etc.)
-
-The unimplemented rules are tracked in #170, and include:
-
-- 14 rules related to string `.format` calls.
-- 4 logical rules.
-- 1 rule related to parsing.
+**Under those conditions, ruff implements 44 out of 60 rules.** (ruff is missing: 14 rules related
+to string `.format` calls, 1 rule related to docstring parsing, and 1 rule related to redefined
+variables.)
 
 Beyond rule-set parity, ruff suffers from the following limitations vis-à-vis Flake8:
 
-1. Flake8 supports a wider range of `noqa` patterns, such as per-file ignores defined in `.flake8`.
-2. Flake8 has a plugin architecture and supports writing custom lint rules.
+1. Flake8 has a plugin architecture and supports writing custom lint rules.
+2. Flake8 supports a wider range of `noqa` patterns, such as per-file ignores defined in `.flake8`.
 3. ruff does not yet support parenthesized context managers.
 
 ## Rules
@@ -178,11 +177,13 @@ Beyond rule-set parity, ruff suffers from the following limitations vis-à-vis F
 | E741 | AmbiguousVariableName | ambiguous variable name '...' |
 | E742 | AmbiguousClassName | ambiguous class name '...' |
 | E743 | AmbiguousFunctionName | ambiguous function name '...' |
-| E902 | IOError | No such file or directory: `...` |
+| E902 | IOError | ... |
 | E999 | SyntaxError | SyntaxError: ... |
 | F401 | UnusedImport | `...` imported but unused |
-| F403 | ImportStarUsage | `from ... import *` used; unable to detect undefined names |
+| F402 | ImportShadowedByLoopVar | import '...' from line 1 shadowed by loop variable |
+| F403 | ImportStarUsed | `from ... import *` used; unable to detect undefined names |
 | F404 | LateFutureImport | from __future__ imports must occur at the beginning of the file |
+| F405 | ImportStarUsage | '...' may be undefined, or defined from star imports: ... |
 | F406 | ImportStarNotPermitted | `from ... import *` only allowed at module level |
 | F407 | FutureFeatureNotDefined | future feature '...' is not defined |
 | F541 | FStringMissingPlaceholders | f-string without any placeholders |
@@ -243,29 +244,29 @@ Add this `pyproject.toml` to the CPython directory:
 ```toml
 [tool.ruff]
 line-length = 88
-exclude = [
-    "./resources/test/cpython/Lib/lib2to3/tests/data/bom.py",
-    "./resources/test/cpython/Lib/lib2to3/tests/data/crlf.py",
-    "./resources/test/cpython/Lib/lib2to3/tests/data/different_encoding.py",
-    "./resources/test/cpython/Lib/lib2to3/tests/data/false_encoding.py",
-    "./resources/test/cpython/Lib/lib2to3/tests/data/py2_test_grammar.py",
-    "./resources/test/cpython/Lib/test/bad_coding2.py",
-    "./resources/test/cpython/Lib/test/badsyntax_3131.py",
-    "./resources/test/cpython/Lib/test/badsyntax_pep3120.py",
-    "./resources/test/cpython/Lib/test/encoded_modules/module_iso_8859_1.py",
-    "./resources/test/cpython/Lib/test/encoded_modules/module_koi8_r.py",
-    "./resources/test/cpython/Lib/test/test_fstring.py",
-    "./resources/test/cpython/Lib/test/test_grammar.py",
-    "./resources/test/cpython/Lib/test/test_importlib/test_util.py",
-    "./resources/test/cpython/Lib/test/test_named_expressions.py",
-    "./resources/test/cpython/Lib/test/test_patma.py",
-    "./resources/test/cpython/Lib/test/test_source_encoding.py",
-    "./resources/test/cpython/Tools/c-analyzer/c_parser/parser/_delim.py",
-    "./resources/test/cpython/Tools/i18n/pygettext.py",
-    "./resources/test/cpython/Tools/test2to3/maintest.py",
-    "./resources/test/cpython/Tools/test2to3/setup.py",
-    "./resources/test/cpython/Tools/test2to3/test/test_foo.py",
-    "./resources/test/cpython/Tools/test2to3/test2to3/hello.py",
+extend-exclude = [
+    "Lib/lib2to3/tests/data/bom.py",
+    "Lib/lib2to3/tests/data/crlf.py",
+    "Lib/lib2to3/tests/data/different_encoding.py",
+    "Lib/lib2to3/tests/data/false_encoding.py",
+    "Lib/lib2to3/tests/data/py2_test_grammar.py",
+    "Lib/test/bad_coding2.py",
+    "Lib/test/badsyntax_3131.py",
+    "Lib/test/badsyntax_pep3120.py",
+    "Lib/test/encoded_modules/module_iso_8859_1.py",
+    "Lib/test/encoded_modules/module_koi8_r.py",
+    "Lib/test/test_fstring.py",
+    "Lib/test/test_grammar.py",
+    "Lib/test/test_importlib/test_util.py",
+    "Lib/test/test_named_expressions.py",
+    "Lib/test/test_patma.py",
+    "Lib/test/test_source_encoding.py",
+    "Tools/c-analyzer/c_parser/parser/_delim.py",
+    "Tools/i18n/pygettext.py",
+    "Tools/test2to3/maintest.py",
+    "Tools/test2to3/setup.py",
+    "Tools/test2to3/test/test_foo.py",
+    "Tools/test2to3/test2to3/hello.py",
 ]
 ```
 
@@ -274,17 +275,21 @@ Next, to benchmark the release build:
 ```shell
 cargo build --release
 
-hyperfine --ignore-failure --warmup 1 \
+hyperfine --ignore-failure --warmup 10 --runs 100 \
   "./target/release/ruff ./resources/test/cpython/ --no-cache" \
   "./target/release/ruff ./resources/test/cpython/"
 
 Benchmark 1: ./target/release/ruff ./resources/test/cpython/ --no-cache
-  Time (mean ± σ):     353.6 ms ±   7.6 ms    [User: 2868.8 ms, System: 171.5 ms]
-  Range (min … max):   344.4 ms … 367.3 ms    10 runs
+  Time (mean ± σ):     297.4 ms ±   4.9 ms    [User: 2460.0 ms, System: 67.2 ms]
+  Range (min … max):   287.7 ms … 312.1 ms    100 runs
+
+  Warning: Ignoring non-zero exit code.
 
 Benchmark 2: ./target/release/ruff ./resources/test/cpython/
-  Time (mean ± σ):      59.6 ms ±   2.5 ms    [User: 36.4 ms, System: 345.6 ms]
-  Range (min … max):    55.9 ms …  67.0 ms    48 runs
+  Time (mean ± σ):      79.6 ms ±   7.3 ms    [User: 59.7 ms, System: 356.1 ms]
+  Range (min … max):    62.4 ms … 111.2 ms    100 runs
+
+  Warning: Ignoring non-zero exit code.
 ```
 
 To benchmark against the ecosystem's existing tools:
@@ -296,11 +301,8 @@ hyperfine --ignore-failure --warmup 5 \
   "pyflakes resources/test/cpython" \
   "autoflake --recursive --expand-star-imports --remove-all-unused-imports --remove-unused-variables --remove-duplicate-keys resources/test/cpython" \
   "pycodestyle resources/test/cpython" \
-  "pycodestyle --select E501 resources/test/cpython" \
   "flake8 resources/test/cpython" \
-  "flake8 --select=F831,F541,F634,F403,F706,F901,E501 resources/test/cpython" \
-  "python -m scripts.run_flake8 resources/test/cpython" \
-  "python -m scripts.run_flake8 resources/test/cpython --select=F831,F541,F634,F403,F706,F901,E501"
+  "python -m scripts.run_flake8 resources/test/cpython"
 ```
 
 In order, these evaluate:
@@ -310,66 +312,58 @@ In order, these evaluate:
 - PyFlakes
 - autoflake
 - pycodestyle
-- pycodestyle, limited to the checks supported by ruff
 - Flake8
-- Flake8, limited to the checks supported by ruff
 - Flake8, with a hack to enable multiprocessing on macOS
-- Flake8, with a hack to enable multiprocessing on macOS, limited to the checks supported by ruff
 
 (You can `poetry install` from `./scripts` to create a working environment for the above.)
 
 ```shell
 Benchmark 1: ./target/release/ruff ./resources/test/cpython/ --no-cache
-  Time (mean ± σ):     469.3 ms ±  16.3 ms    [User: 2663.0 ms, System: 972.5 ms]
-  Range (min … max):   445.2 ms … 494.8 ms    10 runs
+  Time (mean ± σ):     297.9 ms ±   7.0 ms    [User: 2436.6 ms, System: 65.9 ms]
+  Range (min … max):   289.9 ms … 314.6 ms    10 runs
+
+  Warning: Ignoring non-zero exit code.
 
 Benchmark 2: pylint --recursive=y resources/test/cpython/
-  Time (mean ± σ):     27.211 s ±  0.097 s    [User: 26.405 s, System: 0.799 s]
-  Range (min … max):   27.056 s … 27.349 s    10 runs
+  Time (mean ± σ):     37.634 s ±  0.225 s    [User: 36.728 s, System: 0.853 s]
+  Range (min … max):   37.201 s … 38.106 s    10 runs
+
+  Warning: Ignoring non-zero exit code.
 
 Benchmark 3: pyflakes resources/test/cpython
-  Time (mean ± σ):     27.309 s ±  0.033 s    [User: 27.137 s, System: 0.169 s]
-  Range (min … max):   27.267 s … 27.372 s    10 runs
+  Time (mean ± σ):     40.950 s ±  0.449 s    [User: 40.688 s, System: 0.229 s]
+  Range (min … max):   40.348 s … 41.671 s    10 runs
+
+  Warning: Ignoring non-zero exit code.
 
 Benchmark 4: autoflake --recursive --expand-star-imports --remove-all-unused-imports --remove-unused-variables --remove-duplicate-keys resources/test/cpython
-  Time (mean ± σ):      8.027 s ±  0.024 s    [User: 74.255 s, System: 0.953 s]
-  Range (min … max):    7.969 s …  8.052 s    10 runs
+  Time (mean ± σ):     11.562 s ±  0.160 s    [User: 107.022 s, System: 1.143 s]
+  Range (min … max):   11.417 s … 11.917 s    10 runs
 
 Benchmark 5: pycodestyle resources/test/cpython
-  Time (mean ± σ):     41.666 s ±  0.266 s    [User: 41.531 s, System: 0.132 s]
-  Range (min … max):   41.295 s … 41.980 s    10 runs
+  Time (mean ± σ):     67.428 s ±  0.985 s    [User: 67.199 s, System: 0.203 s]
+  Range (min … max):   65.313 s … 68.496 s    10 runs
 
-Benchmark 6: pycodestyle --select E501 resources/test/cpython
-  Time (mean ± σ):     14.547 s ±  0.077 s    [User: 14.466 s, System: 0.079 s]
-  Range (min … max):   14.429 s … 14.695 s    10 runs
+  Warning: Ignoring non-zero exit code.
 
-Benchmark 7: flake8 resources/test/cpython
-  Time (mean ± σ):     75.700 s ±  0.152 s    [User: 75.254 s, System: 0.440 s]
-  Range (min … max):   75.513 s … 76.014 s    10 runs
+Benchmark 6: flake8 resources/test/cpython
+  Time (mean ± σ):     116.099 s ±  1.178 s    [User: 115.217 s, System: 0.845 s]
+  Range (min … max):   114.180 s … 117.724 s    10 runs
 
-Benchmark 8: flake8 --select=F831,F541,F634,F403,F706,F901,E501 resources/test/cpython
-  Time (mean ± σ):     75.122 s ±  0.532 s    [User: 74.677 s, System: 0.440 s]
-  Range (min … max):   74.130 s … 75.606 s    10 runs
+  Warning: Ignoring non-zero exit code.
 
-Benchmark 9: python -m scripts.run_flake8 resources/test/cpython
-  Time (mean ± σ):     12.794 s ±  0.147 s    [User: 90.792 s, System: 0.738 s]
-  Range (min … max):   12.606 s … 13.030 s    10 runs
-
-Benchmark 10: python -m scripts.run_flake8 resources/test/cpython --select=F831,F541,F634,F403,F706,F901,E501
-  Time (mean ± σ):     12.487 s ±  0.118 s    [User: 90.052 s, System: 0.714 s]
-  Range (min … max):   12.265 s … 12.665 s    10 runs
+Benchmark 7: python -m scripts.run_flake8 resources/test/cpython
+  Time (mean ± σ):     20.477 s ±  0.349 s    [User: 142.372 s, System: 1.504 s]
+  Range (min … max):   20.107 s … 21.183 s    10 runs
 
 Summary
   './target/release/ruff ./resources/test/cpython/ --no-cache' ran
-   17.10 ± 0.60 times faster than 'autoflake --recursive --expand-star-imports --remove-all-unused-imports --remove-unused-variables --remove-duplicate-keys resources/test/cpython'
-   26.60 ± 0.96 times faster than 'python -m scripts.run_flake8 resources/test/cpython --select=F831,F541,F634,F403,F706,F901,E501'
-   27.26 ± 1.00 times faster than 'python -m scripts.run_flake8 resources/test/cpython'
-   30.99 ± 1.09 times faster than 'pycodestyle --select E501 resources/test/cpython'
-   57.98 ± 2.03 times faster than 'pylint --recursive=y resources/test/cpython/'
-   58.19 ± 2.02 times faster than 'pyflakes resources/test/cpython'
-   88.77 ± 3.14 times faster than 'pycodestyle resources/test/cpython'
-  160.06 ± 5.68 times faster than 'flake8 --select=F831,F541,F634,F403,F706,F901,E501 resources/test/cpython'
-  161.29 ± 5.61 times faster than 'flake8 resources/test/cpython'
+   38.81 ± 1.05 times faster than 'autoflake --recursive --expand-star-imports --remove-all-unused-imports --remove-unused-variables --remove-duplicate-keys resources/test/cpython'
+   68.74 ± 1.99 times faster than 'python -m scripts.run_flake8 resources/test/cpython'
+  126.33 ± 3.05 times faster than 'pylint --recursive=y resources/test/cpython/'
+  137.46 ± 3.55 times faster than 'pyflakes resources/test/cpython'
+  226.35 ± 6.23 times faster than 'pycodestyle resources/test/cpython'
+  389.73 ± 9.92 times faster than 'flake8 resources/test/cpython'
 ```
 
 ## License

demo/.gitignore

@@ -0,0 +1,24 @@
+# Logs
+logs
+*.log
+npm-debug.log*
+yarn-debug.log*
+yarn-error.log*
+pnpm-debug.log*
+lerna-debug.log*
+
+node_modules
+dist
+dist-ssr
+*.local
+
+# Editor directories and files
+.vscode/*
+!.vscode/extensions.json
+.idea
+.DS_Store
+*.suo
+*.ntvs*
+*.njsproj
+*.sln
+*.sw?

demo/.prettierignore

@@ -0,0 +1,2 @@
+dist
+node_modules

demo/index.css

@@ -0,0 +1,7 @@
+body,
+html,
+#root {
+  margin: 0;
+  width: 100%;
+  height: 100%;
+}

demo/index.html

@@ -0,0 +1,29 @@
+<!DOCTYPE html>
+<html lang="en">
+  <head>
+    <meta charset="UTF-8" />
+    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
+    <meta
+      name="description"
+      content="An in-browser playground for Ruff, an extremely fast Python linter written in Rust."
+    />
+    <meta name="keywords" content="ruff, python, rust, webassembly, wasm" />
+    <title>Ruff Playground</title>
+    <link
+      rel="icon"
+      href="data:image/svg+xml,<svg xmlns=%22http://www.w3.org/2000/svg%22 viewBox=%220 0 100 100%22><text y=%22.9em%22 font-size=%2290%22>🛠️</text></svg>"
+    />
+  </head>
+  <body>
+    <div id="root"></div>
+    <div style="display: flex; position: fixed; right: 16px; top: 16px">
+      <a href="https://GitHub.com/charliermarsh/ruff"
+        ><img
+          src="https://img.shields.io/github/stars/charliermarsh/ruff.svg?style=social&label=GitHub&maxAge=2592000&?logoWidth=100"
+          alt="GitHub stars"
+          style="width: 120px"
+      /></a>
+    </div>
+    <script type="module" src="/src/main.tsx"></script>
+  </body>
+</html>

demo/package.json

@@ -0,0 +1,26 @@
+{
+  "name": "demo",
+  "private": true,
+  "version": "0.0.0",
+  "type": "module",
+  "scripts": {
+    "dev": "vite",
+    "build": "tsc && vite build",
+    "preview": "vite preview",
+    "push": "wrangler pages publish dist --project-name=ruff"
+  },
+  "dependencies": {
+    "@monaco-editor/react": "^4.4.5",
+    "monaco-editor": "^0.34.0",
+    "prettier": "^2.7.1",
+    "react": "^18.2.0",
+    "react-dom": "^18.2.0"
+  },
+  "devDependencies": {
+    "@types/react": "^18.0.17",
+    "@types/react-dom": "^18.0.6",
+    "@vitejs/plugin-react": "^2.1.0",
+    "typescript": "^4.6.4",
+    "vite": "^3.1.0"
+  }
+}

demo/public/vite.svg

@@ -0,0 +1 @@
+<svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" aria-hidden="true" role="img" class="iconify iconify--logos" width="31.88" height="32" preserveAspectRatio="xMidYMid meet" viewBox="0 0 256 257"><defs><linearGradient id="IconifyId1813088fe1fbc01fb466" x1="-.828%" x2="57.636%" y1="7.652%" y2="78.411%"><stop offset="0%" stop-color="#41D1FF"></stop><stop offset="100%" stop-color="#BD34FE"></stop></linearGradient><linearGradient id="IconifyId1813088fe1fbc01fb467" x1="43.376%" x2="50.316%" y1="2.242%" y2="89.03%"><stop offset="0%" stop-color="#FFEA83"></stop><stop offset="8.333%" stop-color="#FFDD35"></stop><stop offset="100%" stop-color="#FFA800"></stop></linearGradient></defs><path fill="url(#IconifyId1813088fe1fbc01fb466)" d="M255.153 37.938L134.897 252.976c-2.483 4.44-8.862 4.466-11.382.048L.875 37.958c-2.746-4.814 1.371-10.646 6.827-9.67l120.385 21.517a6.537 6.537 0 0 0 2.322-.004l117.867-21.483c5.438-.991 9.574 4.796 6.877 9.62Z"></path><path fill="url(#IconifyId1813088fe1fbc01fb467)" d="M185.432.063L96.44 17.501a3.268 3.268 0 0 0-2.634 3.014l-5.474 92.456a3.268 3.268 0 0 0 3.997 3.378l24.777-5.718c2.318-.535 4.413 1.507 3.936 3.838l-7.361 36.047c-.495 2.426 1.782 4.5 4.151 3.78l15.304-4.649c2.372-.72 4.652 1.36 4.15 3.788l-11.698 56.621c-.732 3.542 3.979 5.473 5.943 2.437l1.313-2.028l72.516-144.72c1.215-2.423-.88-5.186-3.54-4.672l-25.505 4.922c-2.396.462-4.435-1.77-3.759-4.114l16.646-57.705c.677-2.35-1.37-4.583-3.769-4.113Z"></path></svg>

demo/src/App.tsx

@@ -0,0 +1,69 @@
+import Editor, { Monaco } from "@monaco-editor/react";
+import { editor, MarkerSeverity } from "monaco-editor/esm/vs/editor/editor.api";
+import React, { useCallback, useEffect, useState } from "react";
+import { DEFAULT_SOURCE } from "./constants";
+import init, { check } from "./pkg/ruff.js";
+import { Check } from "./types";
+import IStandaloneCodeEditor = editor.IStandaloneCodeEditor;
+
+function App() {
+  const [initialized, setInitialized] = useState<boolean>(false);
+  const [_, setCounter] = useState(0);
+  const [monaco, setMonaco] = useState<Monaco | null>(null);
+
+  // Load the WASM module.
+  useEffect(() => {
+    init().then(() => setInitialized(true));
+  }, []);
+
+  const handleEditorChange = useCallback(
+    () => setCounter((counter) => counter + 1),
+    []
+  );
+  const handleEditorDidMount = useCallback(
+    (editor: IStandaloneCodeEditor, monaco: Monaco) => {
+      setMonaco(monaco);
+    },
+    []
+  );
+
+  if (initialized) {
+    if (monaco) {
+      const editor = monaco.editor;
+      if (editor) {
+        const model = editor.getModels()[0];
+        if (model) {
+          const checks: Check[] = JSON.parse(check(model.getValue()));
+          editor.setModelMarkers(
+            model,
+            "owner",
+            checks.map((check) => ({
+              startLineNumber: check.location.row,
+              startColumn: check.location.column,
+              endLineNumber: check.location.row,
+              endColumn: check.location.column,
+              message: `${check.code}: ${check.message}`,
+              severity: MarkerSeverity.Error,
+            }))
+          );
+        }
+      }
+    }
+  }
+
+  return (
+    <Editor
+      height={"100%"}
+      width={"100%"}
+      path={"ruff"}
+      options={{ readOnly: false, minimap: { enabled: false } }}
+      defaultLanguage="python"
+      defaultValue={DEFAULT_SOURCE}
+      theme={"light"}
+      onMount={handleEditorDidMount}
+      onChange={handleEditorChange}
+    />
+  );
+}
+
+export default App;

demo/src/assets/react.svg

@@ -0,0 +1,2 @@
+<svg xmlns="http://www.w3.org/2000/svg" aria-hidden="true" role="img" class="iconify iconify--logos"
+  width="35.93" height="32" preserveAspectRatio="xMidYMid meet" viewBox="0 0 256 228"><path fill="#00D8FF" d="M210.483 73.824a171.49 171.49 0 0 0-8.24-2.597c.465-1.9.893-3.777 1.273-5.621c6.238-30.281 2.16-54.676-11.769-62.708c-13.355-7.7-35.196.329-57.254 19.526a171.23 171.23 0 0 0-6.375 5.848a155.866 155.866 0 0 0-4.241-3.917C100.759 3.829 77.587-4.822 63.673 3.233C50.33 10.957 46.379 33.89 51.995 62.588a170.974 170.974 0 0 0 1.892 8.48c-3.28.932-6.445 1.924-9.474 2.98C17.309 83.498 0 98.307 0 113.668c0 15.865 18.582 31.778 46.812 41.427a145.52 145.52 0 0 0 6.921 2.165a167.467 167.467 0 0 0-2.01 9.138c-5.354 28.2-1.173 50.591 12.134 58.266c13.744 7.926 36.812-.22 59.273-19.855a145.567 145.567 0 0 0 5.342-4.923a168.064 168.064 0 0 0 6.92 6.314c21.758 18.722 43.246 26.282 56.54 18.586c13.731-7.949 18.194-32.003 12.4-61.268a145.016 145.016 0 0 0-1.535-6.842c1.62-.48 3.21-.974 4.76-1.488c29.348-9.723 48.443-25.443 48.443-41.52c0-15.417-17.868-30.326-45.517-39.844Zm-6.365 70.984c-1.4.463-2.836.91-4.3 1.345c-3.24-10.257-7.612-21.163-12.963-32.432c5.106-11 9.31-21.767 12.459-31.957c2.619.758 5.16 1.557 7.61 2.4c23.69 8.156 38.14 20.213 38.14 29.504c0 9.896-15.606 22.743-40.946 31.14Zm-10.514 20.834c2.562 12.94 2.927 24.64 1.23 33.787c-1.524 8.219-4.59 13.698-8.382 15.893c-8.067 4.67-25.32-1.4-43.927-17.412a156.726 156.726 0 0 1-6.437-5.87c7.214-7.889 14.423-17.06 21.459-27.246c12.376-1.098 24.068-2.894 34.671-5.345a134.17 134.17 0 0 1 1.386 6.193ZM87.276 214.515c-7.882 2.783-14.16 2.863-17.955.675c-8.075-4.657-11.432-22.636-6.853-46.752a156.923 156.923 0 0 1 1.869-8.499c10.486 2.32 22.093 3.988 34.498 4.994c7.084 9.967 14.501 19.128 21.976 27.15a134.668 134.668 0 0 1-4.877 4.492c-9.933 8.682-19.886 14.842-28.658 17.94ZM50.35 144.747c-12.483-4.267-22.792-9.812-29.858-15.863c-6.35-5.437-9.555-10.836-9.555-15.216c0-9.322 13.897-21.212 37.076-29.293c2.813-.98 5.757-1.905 8.812-2.773c3.204 10.42 7.406 21.315 12.477 32.332c-5.137 11.18-9.399 22.249-12.634 32.792a134.718 134.718 0 0 1-6.318-1.979Zm12.378-84.26c-4.811-24.587-1.616-43.134 6.425-47.789c8.564-4.958 27.502 2.111 47.463 19.835a144.318 144.318 0 0 1 3.841 3.545c-7.438 7.987-14.787 17.08-21.808 26.988c-12.04 1.116-23.565 2.908-34.161 5.309a160.342 160.342 0 0 1-1.76-7.887Zm110.427 27.268a347.8 347.8 0 0 0-7.785-12.803c8.168 1.033 15.994 2.404 23.343 4.08c-2.206 7.072-4.956 14.465-8.193 22.045a381.151 381.151 0 0 0-7.365-13.322Zm-45.032-43.861c5.044 5.465 10.096 11.566 15.065 18.186a322.04 322.04 0 0 0-30.257-.006c4.974-6.559 10.069-12.652 15.192-18.18ZM82.802 87.83a323.167 323.167 0 0 0-7.227 13.238c-3.184-7.553-5.909-14.98-8.134-22.152c7.304-1.634 15.093-2.97 23.209-3.984a321.524 321.524 0 0 0-7.848 12.897Zm8.081 65.352c-8.385-.936-16.291-2.203-23.593-3.793c2.26-7.3 5.045-14.885 8.298-22.6a321.187 321.187 0 0 0 7.257 13.246c2.594 4.48 5.28 8.868 8.038 13.147Zm37.542 31.03c-5.184-5.592-10.354-11.779-15.403-18.433c4.902.192 9.899.29 14.978.29c5.218 0 10.376-.117 15.453-.343c-4.985 6.774-10.018 12.97-15.028 18.486Zm52.198-57.817c3.422 7.8 6.306 15.345 8.596 22.52c-7.422 1.694-15.436 3.058-23.88 4.071a382.417 382.417 0 0 0 7.859-13.026a347.403 347.403 0 0 0 7.425-13.565Zm-16.898 8.101a358.557 358.557 0 0 1-12.281 19.815a329.4 329.4 0 0 1-23.444.823c-7.967 0-15.716-.248-23.178-.732a310.202 310.202 0 0 1-12.513-19.846h.001a307.41 307.41 0 0 1-10.923-20.627a310.278 310.278 0 0 1 10.89-20.637l-.001.001a307.318 307.318 0 0 1 12.413-19.761c7.613-.576 15.42-.876 23.31-.876H128c7.926 0 15.743.303 23.354.883a329.357 329.357 0 0 1 12.335 19.695a358.489 358.489 0 0 1 11.036 20.54a329.472 329.472 0 0 1-11 20.722Zm22.56-122.124c8.572 4.944 11.906 24.881 6.52 51.026c-.344 1.668-.73 3.367-1.15 5.09c-10.622-2.452-22.155-4.275-34.23-5.408c-7.034-10.017-14.323-19.124-21.64-27.008a160.789 160.789 0 0 1 5.888-5.4c18.9-16.447 36.564-22.941 44.612-18.3ZM128 90.808c12.625 0 22.86 10.235 22.86 22.86s-10.235 22.86-22.86 22.86s-22.86-10.235-22.86-22.86s10.235-22.86 22.86-22.86Z"></path></svg>

demo/src/constants.ts

@@ -0,0 +1,55 @@
+export const DEFAULT_SOURCE = `#: E721
+if type(res) == type(42):
+    pass
+#: E721
+if type(res) != type(""):
+    pass
+#: E721
+import types
+
+if res == types.IntType:
+    pass
+#: E721
+import types
+
+if type(res) is not types.ListType:
+    pass
+#: E721
+assert type(res) == type(False) or type(res) == type(None)
+#: E721
+assert type(res) == type([])
+#: E721
+assert type(res) == type(())
+#: E721
+assert type(res) == type((0,))
+#: E721
+assert type(res) == type((0))
+#: E721
+assert type(res) != type((1,))
+#: E721
+assert type(res) is type((1,))
+#: E721
+assert type(res) is not type((1,))
+#: E721
+assert type(res) == type(
+    [
+        2,
+    ]
+)
+#: E721
+assert type(res) == type(())
+#: E721
+assert type(res) == type((0,))
+
+#: Okay
+import types
+
+if isinstance(res, int):
+    pass
+if isinstance(res, str):
+    pass
+if isinstance(res, types.MethodType):
+    pass
+if type(a) != type(b) or type(a) == type(ccc):
+    pass
+`;

demo/src/main.tsx

@@ -0,0 +1,10 @@
+import React from "react";
+import ReactDOM from "react-dom/client";
+import App from "./App";
+import "../index.css";
+
+ReactDOM.createRoot(document.getElementById("root") as HTMLElement).render(
+  <React.StrictMode>
+    <App />
+  </React.StrictMode>
+);

demo/src/types.ts

@@ -0,0 +1,5 @@
+export type Check = {
+  code: string;
+  message: string;
+  location: { row: number; column: number };
+};

demo/src/vite-env.d.ts

@@ -0,0 +1 @@
+/// <reference types="vite/client" />

demo/tsconfig.json

@@ -0,0 +1,21 @@
+{
+  "compilerOptions": {
+    "target": "ESNext",
+    "useDefineForClassFields": true,
+    "lib": ["DOM", "DOM.Iterable", "ESNext"],
+    "allowJs": false,
+    "skipLibCheck": true,
+    "esModuleInterop": false,
+    "allowSyntheticDefaultImports": true,
+    "strict": true,
+    "forceConsistentCasingInFileNames": true,
+    "module": "ESNext",
+    "moduleResolution": "Node",
+    "resolveJsonModule": true,
+    "isolatedModules": true,
+    "noEmit": true,
+    "jsx": "react-jsx"
+  },
+  "include": ["src"],
+  "references": [{ "path": "./tsconfig.node.json" }]
+}

demo/tsconfig.node.json

@@ -0,0 +1,9 @@
+{
+  "compilerOptions": {
+    "composite": true,
+    "module": "ESNext",
+    "moduleResolution": "Node",
+    "allowSyntheticDefaultImports": true
+  },
+  "include": ["vite.config.ts"]
+}

demo/vite.config.ts

@@ -0,0 +1,7 @@
+import { defineConfig } from "vite";
+import react from "@vitejs/plugin-react";
+
+// https://vitejs.dev/config/
+export default defineConfig({
+  plugins: [react()],
+});

examples/generate_rules_table.rs

@@ -1,56 +1,14 @@
 /// Generate a Markdown-compatible table of supported lint rules.
-use ruff::checks::{CheckKind, RejectedCmpop};
+use ruff::checks::{CheckCode, ALL_CHECK_CODES};
 
 fn main() {
-    let mut check_kinds: Vec<CheckKind> = vec![
-        CheckKind::AmbiguousClassName("...".to_string()),
-        CheckKind::AmbiguousFunctionName("...".to_string()),
-        CheckKind::AmbiguousVariableName("...".to_string()),
-        CheckKind::AssertTuple,
-        CheckKind::BreakOutsideLoop,
-        CheckKind::ContinueOutsideLoop,
-        CheckKind::DefaultExceptNotLast,
-        CheckKind::DoNotAssignLambda,
-        CheckKind::DoNotUseBareExcept,
-        CheckKind::DuplicateArgumentName,
-        CheckKind::FStringMissingPlaceholders,
-        CheckKind::ForwardAnnotationSyntaxError("...".to_string()),
-        CheckKind::FutureFeatureNotDefined("...".to_string()),
-        CheckKind::IOError("...".to_string()),
-        CheckKind::IfTuple,
-        CheckKind::ImportStarNotPermitted("...".to_string()),
-        CheckKind::ImportStarUsage("...".to_string()),
-        CheckKind::InvalidPrintSyntax,
-        CheckKind::IsLiteral,
-        CheckKind::LateFutureImport,
-        CheckKind::LineTooLong(89, 88),
-        CheckKind::ModuleImportNotAtTopOfFile,
-        CheckKind::MultiValueRepeatedKeyLiteral,
-        CheckKind::MultiValueRepeatedKeyVariable("...".to_string()),
-        CheckKind::NoAssertEquals,
-        CheckKind::NoneComparison(RejectedCmpop::Eq),
-        CheckKind::NotInTest,
-        CheckKind::NotIsTest,
-        CheckKind::RaiseNotImplemented,
-        CheckKind::ReturnOutsideFunction,
-        CheckKind::SyntaxError("...".to_string()),
-        CheckKind::TooManyExpressionsInStarredAssignment,
-        CheckKind::TrueFalseComparison(true, RejectedCmpop::Eq),
-        CheckKind::TwoStarredExpressions,
-        CheckKind::TypeComparison,
-        CheckKind::UndefinedExport("...".to_string()),
-        CheckKind::UndefinedLocal("...".to_string()),
-        CheckKind::UndefinedName("...".to_string()),
-        CheckKind::UnusedImport("...".to_string()),
-        CheckKind::UnusedVariable("...".to_string()),
-        CheckKind::UselessObjectInheritance("...".to_string()),
-        CheckKind::YieldOutsideFunction,
-    ];
-    check_kinds.sort_by_key(|check_kind| check_kind.code());
+    let mut check_codes: Vec<CheckCode> = ALL_CHECK_CODES.to_vec();
+    check_codes.sort();
 
     println!("| Code | Name | Message |");
     println!("| ---- | ----- | ------- |");
-    for check_kind in check_kinds {
+    for check_code in check_codes {
+        let check_kind = check_code.kind();
         println!(
             "| {} | {} | {} |",
             check_kind.code().as_str(),

index.html

@@ -0,0 +1,16 @@
+<!DOCTYPE html>
+<html lang="en-US">
+<head>
+  <meta charset="utf-8"/>
+  <title>hello-wasm example</title>
+</head>
+<body>
+<script type="module">
+  import init, {check} from "./pkg/ruff.js";
+
+  init().then(() => {
+    console.log(check("if (1, 2): pass"));
+  });
+</script>
+</body>
+</html>

resources/test/fixtures/E501.py

@@ -4,3 +4,6 @@
 
 Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.
 """
+
+_ = "---------------------------------------------------------------------------AAAAAAA"
+_ = "---------------------------------------------------------------------------亜亜亜亜亜亜亜"

resources/test/fixtures/F402.py

@@ -0,0 +1,9 @@
+import os
+import os.path as path
+
+
+for os in range(3):
+    pass
+
+for path in range(3):
+    pass

resources/test/fixtures/F405.py

@@ -0,0 +1,11 @@
+from mymodule import *
+
+
+def print_name():
+    print(name)
+
+
+def print_name(name):
+    print(name)
+
+__all__ = ['a']

resources/test/fixtures/F821.py

@@ -82,3 +82,10 @@ class Ticket:
 def update_tomato():
     print(TOMATO)
     TOMATO = "cherry tomato"
+
+
+A = f'{B}'
+A = (
+    f'B'
+    f'{B}'
+)

resources/test/fixtures/F841.py

@@ -22,3 +22,10 @@ def g():
 
     bar = (1, 2)
     (c, d) = bar
+
+    (x, y) = baz = bar
+
+
+def h():
+    locals()
+    x = 1

resources/test/fixtures/pyproject.toml

@@ -3,49 +3,5 @@ line-length = 88
 extend-exclude = [
     "excluded.py",
     "migrations",
-    "./resources/test/fixtures/directory/also_excluded.py",
-]
-select = [
-    "E402",
-    "E501",
-    "E711",
-    "E712",
-    "E713",
-    "E714",
-    "E721",
-    "E722",
-    "E731",
-    "E741",
-    "E742",
-    "E743",
-    "E902",
-    "E999",
-    "F401",
-    "F403",
-    "F404",
-    "F406",
-    "F407",
-    "F541",
-    "F601",
-    "F602",
-    "F621",
-    "F622",
-    "F631",
-    "F632",
-    "F633",
-    "F634",
-    "F701",
-    "F702",
-    "F704",
-    "F706",
-    "F707",
-    "F722",
-    "F821",
-    "F822",
-    "F823",
-    "F831",
-    "F841",
-    "F901",
-    "R001",
-    "R002",
+    "directory/also_excluded.py",
 ]

src/ast/checks.rs

@@ -7,7 +7,7 @@ use rustpython_parser::ast::{
 };
 
 use crate::ast::operations::SourceCodeLocator;
-use crate::ast::types::{Binding, BindingKind, Scope};
+use crate::ast::types::{Binding, BindingKind, CheckLocator, FunctionScope, Scope, ScopeKind};
 use crate::autofix::{fixer, fixes};
 use crate::checks::{Check, CheckKind, Fix, RejectedCmpop};
 
@@ -37,6 +37,7 @@ pub fn check_not_tests(
     operand: &Expr,
     check_not_in: bool,
     check_not_is: bool,
+    locator: &dyn CheckLocator,
 ) -> Vec<Check> {
     let mut checks: Vec<Check> = vec![];
 
@@ -46,12 +47,18 @@ pub fn check_not_tests(
                 match op {
                     Cmpop::In => {
                         if check_not_in {
-                            checks.push(Check::new(CheckKind::NotInTest, operand.location));
+                            checks.push(Check::new(
+                                CheckKind::NotInTest,
+                                locator.locate_check(operand.location),
+                            ));
                         }
                     }
                     Cmpop::Is => {
                         if check_not_is {
-                            checks.push(Check::new(CheckKind::NotIsTest, operand.location));
+                            checks.push(Check::new(
+                                CheckKind::NotIsTest,
+                                locator.locate_check(operand.location),
+                            ));
                         }
                     }
                     _ => {}
@@ -64,9 +71,16 @@ pub fn check_not_tests(
 }
 
 /// Check UnusedVariable compliance.
-pub fn check_unused_variables(scope: &Scope) -> Vec<Check> {
+pub fn check_unused_variables(scope: &Scope, locator: &dyn CheckLocator) -> Vec<Check> {
     let mut checks: Vec<Check> = vec![];
 
+    if matches!(
+        scope.kind,
+        ScopeKind::Function(FunctionScope { uses_locals: true })
+    ) {
+        return checks;
+    }
+
     for (name, binding) in scope.values.iter() {
         // TODO(charlie): Ignore if using `locals`.
         if binding.used.is_none()
@@ -78,7 +92,7 @@ pub fn check_unused_variables(scope: &Scope) -> Vec<Check> {
         {
             checks.push(Check::new(
                 CheckKind::UnusedVariable(name.to_string()),
-                binding.location,
+                locator.locate_check(binding.location),
             ));
         }
     }
@@ -292,6 +306,7 @@ pub fn check_repeated_keys(
     keys: &Vec<Expr>,
     check_repeated_literals: bool,
     check_repeated_variables: bool,
+    locator: &dyn CheckLocator,
 ) -> Vec<Check> {
     let mut checks: Vec<Check> = vec![];
 
@@ -306,7 +321,7 @@ pub fn check_repeated_keys(
                     if check_repeated_literals && v1 == v2 {
                         checks.push(Check::new(
                             CheckKind::MultiValueRepeatedKeyLiteral,
-                            k2.location,
+                            locator.locate_check(k2.location),
                         ))
                     }
                 }
@@ -314,7 +329,7 @@ pub fn check_repeated_keys(
                     if check_repeated_variables && v1 == v2 {
                         checks.push(Check::new(
                             CheckKind::MultiValueRepeatedKeyVariable((*v2).to_string()),
-                            k2.location,
+                            locator.locate_check(k2.location),
                         ))
                     }
                 }
@@ -333,6 +348,7 @@ pub fn check_literal_comparisons(
     comparators: &Vec<Expr>,
     check_none_comparisons: bool,
     check_true_false_comparisons: bool,
+    locator: &dyn CheckLocator,
 ) -> Vec<Check> {
     let mut checks: Vec<Check> = vec![];
 
@@ -352,13 +368,13 @@ pub fn check_literal_comparisons(
         if matches!(op, Cmpop::Eq) {
             checks.push(Check::new(
                 CheckKind::NoneComparison(RejectedCmpop::Eq),
-                comparator.location,
+                locator.locate_check(comparator.location),
             ));
         }
         if matches!(op, Cmpop::NotEq) {
             checks.push(Check::new(
                 CheckKind::NoneComparison(RejectedCmpop::NotEq),
-                comparator.location,
+                locator.locate_check(comparator.location),
             ));
         }
     }
@@ -372,13 +388,13 @@ pub fn check_literal_comparisons(
             if matches!(op, Cmpop::Eq) {
                 checks.push(Check::new(
                     CheckKind::TrueFalseComparison(value, RejectedCmpop::Eq),
-                    comparator.location,
+                    locator.locate_check(comparator.location),
                 ));
             }
             if matches!(op, Cmpop::NotEq) {
                 checks.push(Check::new(
                     CheckKind::TrueFalseComparison(value, RejectedCmpop::NotEq),
-                    comparator.location,
+                    locator.locate_check(comparator.location),
                 ));
             }
         }
@@ -398,13 +414,13 @@ pub fn check_literal_comparisons(
             if matches!(op, Cmpop::Eq) {
                 checks.push(Check::new(
                     CheckKind::NoneComparison(RejectedCmpop::Eq),
-                    comparator.location,
+                    locator.locate_check(comparator.location),
                 ));
             }
             if matches!(op, Cmpop::NotEq) {
                 checks.push(Check::new(
                     CheckKind::NoneComparison(RejectedCmpop::NotEq),
-                    comparator.location,
+                    locator.locate_check(comparator.location),
                 ));
             }
         }
@@ -418,13 +434,13 @@ pub fn check_literal_comparisons(
                 if matches!(op, Cmpop::Eq) {
                     checks.push(Check::new(
                         CheckKind::TrueFalseComparison(value, RejectedCmpop::Eq),
-                        comparator.location,
+                        locator.locate_check(comparator.location),
                     ));
                 }
                 if matches!(op, Cmpop::NotEq) {
                     checks.push(Check::new(
                         CheckKind::TrueFalseComparison(value, RejectedCmpop::NotEq),
-                        comparator.location,
+                        locator.locate_check(comparator.location),
                     ));
                 }
             }
@@ -521,9 +537,9 @@ pub fn check_type_comparison(
 /// Check TwoStarredExpressions and TooManyExpressionsInStarredAssignment compliance.
 pub fn check_starred_expressions(
     elts: &[Expr],
-    location: Location,
     check_too_many_expressions: bool,
     check_two_starred_expressions: bool,
+    location: Location,
 ) -> Option<Check> {
     let mut has_starred: bool = false;
     let mut starred_index: Option<usize> = None;
@@ -556,6 +572,7 @@ pub fn check_break_outside_loop(
     stmt: &Stmt,
     parents: &[&Stmt],
     parent_stack: &[usize],
+    locator: &dyn CheckLocator,
 ) -> Option<Check> {
     let mut allowed: bool = false;
     let mut parent = stmt;
@@ -582,7 +599,10 @@ pub fn check_break_outside_loop(
     }
 
     if !allowed {
-        Some(Check::new(CheckKind::BreakOutsideLoop, stmt.location))
+        Some(Check::new(
+            CheckKind::BreakOutsideLoop,
+            locator.locate_check(stmt.location),
+        ))
     } else {
         None
     }
@@ -593,6 +613,7 @@ pub fn check_continue_outside_loop(
     stmt: &Stmt,
     parents: &[&Stmt],
     parent_stack: &[usize],
+    locator: &dyn CheckLocator,
 ) -> Option<Check> {
     let mut allowed: bool = false;
     let mut parent = stmt;
@@ -619,7 +640,10 @@ pub fn check_continue_outside_loop(
     }
 
     if !allowed {
-        Some(Check::new(CheckKind::ContinueOutsideLoop, stmt.location))
+        Some(Check::new(
+            CheckKind::ContinueOutsideLoop,
+            locator.locate_check(stmt.location),
+        ))
     } else {
         None
     }

src/ast/operations.rs

@@ -101,11 +101,13 @@ pub fn in_nested_block(parent_stack: &[usize], parents: &[&Stmt]) -> bool {
 /// Check if a node represents an unpacking assignment.
 pub fn is_unpacking_assignment(stmt: &Stmt) -> bool {
     if let StmtKind::Assign { targets, value, .. } = &stmt.node {
-        for child in targets {
-            match &child.node {
-                ExprKind::Set { .. } | ExprKind::List { .. } | ExprKind::Tuple { .. } => {}
-                _ => return false,
-            }
+        if !targets.iter().any(|child| {
+            matches!(
+                child.node,
+                ExprKind::Set { .. } | ExprKind::List { .. } | ExprKind::Tuple { .. }
+            )
+        }) {
+            return false;
         }
         match &value.node {
             ExprKind::Set { .. } | ExprKind::List { .. } | ExprKind::Tuple { .. } => return false,

src/ast/types.rs

@@ -8,10 +8,15 @@ fn id() -> usize {
     COUNTER.fetch_add(1, Ordering::Relaxed)
 }
 
+#[derive(Clone, Debug, Default)]
+pub struct FunctionScope {
+    pub uses_locals: bool,
+}
+
 #[derive(Clone, Debug)]
 pub enum ScopeKind {
     Class,
-    Function,
+    Function(FunctionScope),
     Generator,
     Module,
 }
@@ -20,6 +25,7 @@ pub enum ScopeKind {
 pub struct Scope {
     pub id: usize,
     pub kind: ScopeKind,
+    pub import_starred: bool,
     pub values: BTreeMap<String, Binding>,
 }
 
@@ -28,6 +34,7 @@ impl Scope {
         Scope {
             id: id(),
             kind,
+            import_starred: false,
             values: BTreeMap::new(),
         }
     }
@@ -39,6 +46,7 @@ pub enum BindingKind {
     Argument,
     Assignment,
     Binding,
+    LoopVar,
     Builtin,
     ClassDefinition,
     Definition,
@@ -57,3 +65,7 @@ pub struct Binding {
     /// last used.
     pub used: Option<(usize, Location)>,
 }
+
+pub trait CheckLocator {
+    fn locate_check(&self, default: Location) -> Location;
+}

src/autofix/fixer.rs

@@ -1,11 +1,3 @@
-use std::fs;
-use std::path::Path;
-
-use anyhow::Result;
-use rustpython_parser::ast::Location;
-
-use crate::checks::{Check, Fix};
-
 #[derive(Hash)]
 pub enum Mode {
     Generate,
@@ -21,196 +13,3 @@ impl From<bool> for Mode {
         }
     }
 }
-
-/// Auto-fix errors in a file, and write the fixed source code to disk.
-pub fn fix_file(checks: &mut [Check], contents: &str, path: &Path) -> Result<()> {
-    if checks.iter().all(|check| check.fix.is_none()) {
-        return Ok(());
-    }
-
-    let output = apply_fixes(
-        checks.iter_mut().filter_map(|check| check.fix.as_mut()),
-        contents,
-    );
-
-    fs::write(path, output).map_err(|e| e.into())
-}
-
-/// Apply a series of fixes.
-fn apply_fixes<'a>(fixes: impl Iterator<Item = &'a mut Fix>, contents: &str) -> String {
-    let lines: Vec<&str> = contents.lines().collect();
-
-    let mut output = "".to_string();
-    let mut last_pos: Location = Location::new(0, 0);
-
-    for fix in fixes {
-        // Best-effort approach: if this fix overlaps with a fix we've already applied, skip it.
-        if last_pos > fix.start {
-            continue;
-        }
-
-        if fix.start.row() > last_pos.row() {
-            if last_pos.row() > 0 || last_pos.column() > 0 {
-                output.push_str(&lines[last_pos.row() - 1][last_pos.column() - 1..]);
-                output.push('\n');
-            }
-            for line in &lines[last_pos.row()..fix.start.row() - 1] {
-                output.push_str(line);
-                output.push('\n');
-            }
-            output.push_str(&lines[fix.start.row() - 1][..fix.start.column() - 1]);
-            output.push_str(&fix.content);
-        } else {
-            output.push_str(
-                &lines[last_pos.row() - 1][last_pos.column() - 1..fix.start.column() - 1],
-            );
-            output.push_str(&fix.content);
-        }
-
-        last_pos = fix.end;
-        fix.applied = true;
-    }
-
-    if last_pos.row() > 0 || last_pos.column() > 0 {
-        output.push_str(&lines[last_pos.row() - 1][last_pos.column() - 1..]);
-        output.push('\n');
-    }
-    for line in &lines[last_pos.row()..] {
-        output.push_str(line);
-        output.push('\n');
-    }
-
-    output
-}
-
-#[cfg(test)]
-mod tests {
-    use anyhow::Result;
-    use rustpython_parser::ast::Location;
-
-    use crate::autofix::fixer::apply_fixes;
-    use crate::checks::Fix;
-
-    #[test]
-    fn empty_file() -> Result<()> {
-        let mut fixes = vec![];
-        let actual = apply_fixes(fixes.iter_mut(), "");
-        let expected = "";
-
-        assert_eq!(actual, expected);
-
-        Ok(())
-    }
-
-    #[test]
-    fn apply_single_replacement() -> Result<()> {
-        let mut fixes = vec![Fix {
-            content: "Bar".to_string(),
-            start: Location::new(1, 9),
-            end: Location::new(1, 15),
-            applied: false,
-        }];
-        let actual = apply_fixes(
-            fixes.iter_mut(),
-            "class A(object):
-        ...
-",
-        );
-
-        let expected = "class A(Bar):
-        ...
-";
-
-        assert_eq!(actual, expected);
-
-        Ok(())
-    }
-
-    #[test]
-    fn apply_single_removal() -> Result<()> {
-        let mut fixes = vec![Fix {
-            content: "".to_string(),
-            start: Location::new(1, 8),
-            end: Location::new(1, 16),
-            applied: false,
-        }];
-        let actual = apply_fixes(
-            fixes.iter_mut(),
-            "class A(object):
-        ...
-",
-        );
-
-        let expected = "class A:
-        ...
-";
-
-        assert_eq!(actual, expected);
-
-        Ok(())
-    }
-
-    #[test]
-    fn apply_double_removal() -> Result<()> {
-        let mut fixes = vec![
-            Fix {
-                content: "".to_string(),
-                start: Location::new(1, 8),
-                end: Location::new(1, 17),
-                applied: false,
-            },
-            Fix {
-                content: "".to_string(),
-                start: Location::new(1, 17),
-                end: Location::new(1, 24),
-                applied: false,
-            },
-        ];
-        let actual = apply_fixes(
-            fixes.iter_mut(),
-            "class A(object, object):
-        ...
-",
-        );
-
-        let expected = "class A:
-        ...
-";
-
-        assert_eq!(actual, expected);
-
-        Ok(())
-    }
-
-    #[test]
-    fn ignore_overlapping_fixes() -> Result<()> {
-        let mut fixes = vec![
-            Fix {
-                content: "".to_string(),
-                start: Location::new(1, 8),
-                end: Location::new(1, 16),
-                applied: false,
-            },
-            Fix {
-                content: "ignored".to_string(),
-                start: Location::new(1, 10),
-                end: Location::new(1, 12),
-                applied: false,
-            },
-        ];
-        let actual = apply_fixes(
-            fixes.iter_mut(),
-            "class A(object):
-    ...
-",
-        );
-
-        let expected = "class A:
-    ...
-";
-
-        assert_eq!(actual, expected);
-
-        Ok(())
-    }
-}

src/cache.rs

@@ -1,152 +0,0 @@
-use std::collections::hash_map::DefaultHasher;
-use std::fs::{create_dir_all, File, Metadata};
-use std::hash::{Hash, Hasher};
-use std::io::Write;
-use std::path::Path;
-
-use anyhow::Result;
-use cacache::Error::EntryNotFound;
-use filetime::FileTime;
-use log::error;
-use serde::{Deserialize, Serialize};
-
-use crate::autofix::fixer;
-use crate::message::Message;
-use crate::settings::Settings;
-
-const VERSION: &str = env!("CARGO_PKG_VERSION");
-
-#[derive(Serialize, Deserialize)]
-struct CacheMetadata {
-    mtime: i64,
-}
-
-#[derive(Serialize)]
-struct CheckResultRef<'a> {
-    metadata: &'a CacheMetadata,
-    messages: &'a [Message],
-}
-
-#[derive(Deserialize)]
-struct CheckResult {
-    metadata: CacheMetadata,
-    messages: Vec<Message>,
-}
-
-pub enum Mode {
-    ReadWrite,
-    ReadOnly,
-    WriteOnly,
-    None,
-}
-
-impl Mode {
-    fn allow_read(&self) -> bool {
-        match self {
-            Mode::ReadWrite => true,
-            Mode::ReadOnly => true,
-            Mode::WriteOnly => false,
-            Mode::None => false,
-        }
-    }
-
-    fn allow_write(&self) -> bool {
-        match self {
-            Mode::ReadWrite => true,
-            Mode::ReadOnly => false,
-            Mode::WriteOnly => true,
-            Mode::None => false,
-        }
-    }
-}
-
-impl From<bool> for Mode {
-    fn from(value: bool) -> Self {
-        match value {
-            true => Mode::ReadWrite,
-            false => Mode::None,
-        }
-    }
-}
-
-fn cache_dir() -> &'static str {
-    "./.ruff_cache"
-}
-
-fn cache_key(path: &Path, settings: &Settings, autofix: &fixer::Mode) -> String {
-    let mut hasher = DefaultHasher::new();
-    settings.hash(&mut hasher);
-    autofix.hash(&mut hasher);
-    format!(
-        "{}@{}@{}",
-        path.canonicalize().unwrap().to_string_lossy(),
-        VERSION,
-        hasher.finish()
-    )
-}
-
-pub fn init() -> Result<()> {
-    let gitignore_path = Path::new(cache_dir()).join(".gitignore");
-    if gitignore_path.exists() {
-        return Ok(());
-    }
-    create_dir_all(cache_dir())?;
-    let mut file = File::create(gitignore_path)?;
-    file.write_all(b"*").map_err(|e| e.into())
-}
-
-pub fn get(
-    path: &Path,
-    metadata: &Metadata,
-    settings: &Settings,
-    autofix: &fixer::Mode,
-    mode: &Mode,
-) -> Option<Vec<Message>> {
-    if !mode.allow_read() {
-        return None;
-    };
-
-    match cacache::read_sync(cache_dir(), cache_key(path, settings, autofix)) {
-        Ok(encoded) => match bincode::deserialize::<CheckResult>(&encoded[..]) {
-            Ok(CheckResult {
-                metadata: CacheMetadata { mtime },
-                messages,
-            }) => {
-                if FileTime::from_last_modification_time(metadata).unix_seconds() == mtime {
-                    return Some(messages);
-                }
-            }
-            Err(e) => error!("Failed to deserialize encoded cache entry: {e:?}"),
-        },
-        Err(EntryNotFound(_, _)) => {}
-        Err(e) => error!("Failed to read from cache: {e:?}"),
-    }
-    None
-}
-
-pub fn set(
-    path: &Path,
-    metadata: &Metadata,
-    settings: &Settings,
-    autofix: &fixer::Mode,
-    messages: &[Message],
-    mode: &Mode,
-) {
-    if !mode.allow_write() {
-        return;
-    };
-
-    let check_result = CheckResultRef {
-        metadata: &CacheMetadata {
-            mtime: FileTime::from_last_modification_time(metadata).unix_seconds(),
-        },
-        messages,
-    };
-    if let Err(e) = cacache::write_sync(
-        cache_dir(),
-        cache_key(path, settings, autofix),
-        bincode::serialize(&check_result).unwrap(),
-    ) {
-        error!("Failed to write to cache: {e:?}")
-    }
-}

src/check_ast.rs

@@ -9,7 +9,7 @@ use rustpython_parser::parser;
 
 use crate::ast::operations::{extract_all_names, SourceCodeLocator};
 use crate::ast::relocate::relocate_expr;
-use crate::ast::types::{Binding, BindingKind, Scope, ScopeKind};
+use crate::ast::types::{Binding, BindingKind, CheckLocator, FunctionScope, Scope, ScopeKind};
 use crate::ast::visitor::{walk_excepthandler, Visitor};
 use crate::ast::{checks, operations, visitor};
 use crate::autofix::fixer;
@@ -42,7 +42,7 @@ struct Checker<'a> {
     deferred_lambdas: Vec<(&'a Expr, Vec<usize>, Vec<usize>)>,
     deferred_assignments: Vec<usize>,
     // Derivative state.
-    in_f_string: bool,
+    in_f_string: Option<Location>,
     in_annotation: bool,
     in_literal: bool,
     seen_non_import: bool,
@@ -74,7 +74,7 @@ impl<'a> Checker<'a> {
             deferred_functions: vec![],
             deferred_lambdas: vec![],
             deferred_assignments: vec![],
-            in_f_string: false,
+            in_f_string: None,
             in_annotation: false,
             in_literal: false,
             seen_non_import: false,
@@ -171,7 +171,6 @@ where
         // Pre-visit.
         match &stmt.node {
             StmtKind::Global { names } | StmtKind::Nonlocal { names } => {
-                // TODO(charlie): Handle doctests.
                 let global_scope_id = self.scopes[GLOBAL_SCOPE_INDEX].id;
 
                 let current_scope =
@@ -193,25 +192,34 @@ where
                 }
 
                 if self.settings.select.contains(&CheckCode::E741) {
-                    self.checks.extend(names.iter().filter_map(|name| {
-                        checks::check_ambiguous_variable_name(name, stmt.location)
-                    }));
+                    let location = self.locate_check(stmt.location);
+                    self.checks.extend(
+                        names.iter().filter_map(|name| {
+                            checks::check_ambiguous_variable_name(name, location)
+                        }),
+                    );
                 }
             }
             StmtKind::Break => {
                 if self.settings.select.contains(&CheckCode::F701) {
-                    if let Some(check) =
-                        checks::check_break_outside_loop(stmt, &self.parents, &self.parent_stack)
-                    {
+                    if let Some(check) = checks::check_break_outside_loop(
+                        stmt,
+                        &self.parents,
+                        &self.parent_stack,
+                        self,
+                    ) {
                         self.checks.push(check);
                     }
                 }
             }
             StmtKind::Continue => {
                 if self.settings.select.contains(&CheckCode::F702) {
-                    if let Some(check) =
-                        checks::check_continue_outside_loop(stmt, &self.parents, &self.parent_stack)
-                    {
+                    if let Some(check) = checks::check_continue_outside_loop(
+                        stmt,
+                        &self.parents,
+                        &self.parent_stack,
+                        self,
+                    ) {
                         self.checks.push(check);
                     }
                 }
@@ -231,8 +239,10 @@ where
                 ..
             } => {
                 if self.settings.select.contains(&CheckCode::E743) {
-                    if let Some(check) = checks::check_ambiguous_function_name(name, stmt.location)
-                    {
+                    if let Some(check) = checks::check_ambiguous_function_name(
+                        name,
+                        self.locate_check(stmt.location),
+                    ) {
                         self.checks.push(check);
                     }
                 }
@@ -293,7 +303,7 @@ where
                             ScopeKind::Class | ScopeKind::Module => {
                                 self.checks.push(Check::new(
                                     CheckKind::ReturnOutsideFunction,
-                                    stmt.location,
+                                    self.locate_check(stmt.location),
                                 ));
                             }
                             _ => {}
@@ -325,7 +335,9 @@ where
                 }
 
                 if self.settings.select.contains(&CheckCode::E742) {
-                    if let Some(check) = checks::check_ambiguous_class_name(name, stmt.location) {
+                    if let Some(check) =
+                        checks::check_ambiguous_class_name(name, self.locate_check(stmt.location))
+                    {
                         self.checks.push(check);
                     }
                 }
@@ -351,7 +363,7 @@ where
                 {
                     self.checks.push(Check::new(
                         CheckKind::ModuleImportNotAtTopOfFile,
-                        stmt.location,
+                        self.locate_check(stmt.location),
                     ));
                 }
 
@@ -391,7 +403,11 @@ where
                     }
                 }
             }
-            StmtKind::ImportFrom { names, module, .. } => {
+            StmtKind::ImportFrom {
+                names,
+                module,
+                level,
+            } => {
                 if self
                     .settings
                     .select
@@ -401,7 +417,7 @@ where
                 {
                     self.checks.push(Check::new(
                         CheckKind::ModuleImportNotAtTopOfFile,
-                        stmt.location,
+                        self.locate_check(stmt.location),
                     ));
                 }
 
@@ -437,18 +453,26 @@ where
                         {
                             self.checks.push(Check::new(
                                 CheckKind::FutureFeatureNotDefined(alias.node.name.to_string()),
-                                stmt.location,
+                                self.locate_check(stmt.location),
                             ));
                         }
 
                         if self.settings.select.contains(&CheckCode::F404) && !self.futures_allowed
                         {
-                            self.checks
-                                .push(Check::new(CheckKind::LateFutureImport, stmt.location));
+                            self.checks.push(Check::new(
+                                CheckKind::LateFutureImport,
+                                self.locate_check(stmt.location),
+                            ));
                         }
                     } else if alias.node.name == "*" {
+                        let module_name = format!(
+                            "{}{}",
+                            ".".repeat(level.unwrap_or_default()),
+                            module.clone().unwrap_or_else(|| "module".to_string()),
+                        );
+
                         self.add_binding(
-                            name,
+                            module_name.to_string(),
                             Binding {
                                 kind: BindingKind::StarImportation,
                                 used: None,
@@ -456,27 +480,29 @@ where
                             },
                         );
 
-                        if self.settings.select.contains(&CheckCode::F403) {
-                            self.checks.push(Check::new(
-                                CheckKind::ImportStarUsage(
-                                    module.clone().unwrap_or_else(|| "module".to_string()),
-                                ),
-                                stmt.location,
-                            ));
-                        }
-
                         if self.settings.select.contains(&CheckCode::F406) {
                             let scope = &self.scopes
                                 [*(self.scope_stack.last().expect("No current scope found."))];
                             if !matches!(scope.kind, ScopeKind::Module) {
                                 self.checks.push(Check::new(
-                                    CheckKind::ImportStarNotPermitted(
-                                        module.clone().unwrap_or_else(|| "module".to_string()),
-                                    ),
-                                    stmt.location,
+                                    CheckKind::ImportStarNotPermitted(module_name.to_string()),
+                                    self.locate_check(stmt.location),
                                 ));
                             }
                         }
+
+                        if self.settings.select.contains(&CheckCode::F403) {
+                            self.checks.push(Check::new(
+                                CheckKind::ImportStarUsed(module_name.to_string()),
+                                self.locate_check(stmt.location),
+                            ));
+                        }
+
+                        let scope = &mut self.scopes[*(self
+                            .scope_stack
+                            .last_mut()
+                            .expect("No current scope found."))];
+                        scope.import_starred = true;
                     } else {
                         let binding = Binding {
                             kind: BindingKind::Importation(match module {
@@ -504,14 +530,18 @@ where
             }
             StmtKind::If { test, .. } => {
                 if self.settings.select.contains(&CheckCode::F634) {
-                    if let Some(check) = checks::check_if_tuple(test, stmt.location) {
+                    if let Some(check) =
+                        checks::check_if_tuple(test, self.locate_check(stmt.location))
+                    {
                         self.checks.push(check);
                     }
                 }
             }
             StmtKind::Assert { test, .. } => {
                 if self.settings.select.contains(CheckKind::AssertTuple.code()) {
-                    if let Some(check) = checks::check_assert_tuple(test, stmt.location) {
+                    if let Some(check) =
+                        checks::check_assert_tuple(test, self.locate_check(stmt.location))
+                    {
                         self.checks.push(check);
                     }
                 }
@@ -525,7 +555,9 @@ where
             }
             StmtKind::Assign { value, .. } => {
                 if self.settings.select.contains(&CheckCode::E731) {
-                    if let Some(check) = checks::check_do_not_assign_lambda(value, stmt.location) {
+                    if let Some(check) =
+                        checks::check_do_not_assign_lambda(value, self.locate_check(stmt.location))
+                    {
                         self.checks.push(check);
                     }
                 }
@@ -533,9 +565,10 @@ where
             StmtKind::AnnAssign { value, .. } => {
                 if self.settings.select.contains(&CheckCode::E731) {
                     if let Some(value) = value {
-                        if let Some(check) =
-                            checks::check_do_not_assign_lambda(value, stmt.location)
-                        {
+                        if let Some(check) = checks::check_do_not_assign_lambda(
+                            value,
+                            self.locate_check(stmt.location),
+                        ) {
                             self.checks.push(check);
                         }
                     }
@@ -590,7 +623,6 @@ where
         let prev_in_literal = self.in_literal;
         let prev_in_annotation = self.in_annotation;
 
-        // Important:
         if self.in_annotation && self.annotations_future_enabled {
             self.deferred_annotations.push((
                 expr,
@@ -616,9 +648,9 @@ where
                         self.settings.select.contains(&CheckCode::F622);
                     if let Some(check) = checks::check_starred_expressions(
                         elts,
-                        expr.location,
                         check_too_many_expressions,
                         check_two_starred_expressions,
+                        self.locate_check(expr.location),
                     ) {
                         self.checks.push(check);
                     }
@@ -628,9 +660,10 @@ where
                 ExprContext::Load => self.handle_node_load(expr),
                 ExprContext::Store => {
                     if self.settings.select.contains(&CheckCode::E741) {
-                        if let Some(check) =
-                            checks::check_ambiguous_variable_name(id, expr.location)
-                        {
+                        if let Some(check) = checks::check_ambiguous_variable_name(
+                            id,
+                            self.locate_check(expr.location),
+                        ) {
                             self.checks.push(check);
                         }
                     }
@@ -646,6 +679,21 @@ where
                         self.checks.push(check)
                     }
                 }
+
+                if let ExprKind::Name { id, ctx } = &func.node {
+                    if id == "locals" && matches!(ctx, ExprContext::Load) {
+                        let scope = &mut self.scopes[*(self
+                            .scope_stack
+                            .last_mut()
+                            .expect("No current scope found."))];
+                        if matches!(
+                            scope.kind,
+                            ScopeKind::Function(FunctionScope { uses_locals: false })
+                        ) {
+                            scope.kind = ScopeKind::Function(FunctionScope { uses_locals: true });
+                        }
+                    }
+                }
             }
             ExprKind::Dict { keys, .. } => {
                 let check_repeated_literals = self.settings.select.contains(&CheckCode::F601);
@@ -655,6 +703,7 @@ where
                         keys,
                         check_repeated_literals,
                         check_repeated_variables,
+                        self,
                     ));
                 }
             }
@@ -667,12 +716,14 @@ where
                     .contains(CheckKind::YieldOutsideFunction.code())
                     && matches!(scope.kind, ScopeKind::Class | ScopeKind::Module)
                 {
-                    self.checks
-                        .push(Check::new(CheckKind::YieldOutsideFunction, expr.location));
+                    self.checks.push(Check::new(
+                        CheckKind::YieldOutsideFunction,
+                        self.locate_check(expr.location),
+                    ));
                 }
             }
             ExprKind::JoinedStr { values } => {
-                if !self.in_f_string
+                if self.in_f_string.is_none()
                     && self
                         .settings
                         .select
@@ -683,10 +734,10 @@ where
                 {
                     self.checks.push(Check::new(
                         CheckKind::FStringMissingPlaceholders,
-                        expr.location,
+                        self.locate_check(expr.location),
                     ));
                 }
-                self.in_f_string = true;
+                self.in_f_string = Some(expr.location);
             }
             ExprKind::BinOp {
                 left,
@@ -719,6 +770,7 @@ where
                         operand,
                         check_not_in,
                         check_not_is,
+                        self,
                     ));
                 }
             }
@@ -736,6 +788,7 @@ where
                         comparators,
                         check_none_comparisons,
                         check_true_false_comparisons,
+                        self,
                     ));
                 }
 
@@ -744,7 +797,7 @@ where
                         left,
                         ops,
                         comparators,
-                        expr.location,
+                        self.locate_check(expr.location),
                     ));
                 }
 
@@ -752,7 +805,7 @@ where
                     self.checks.extend(checks::check_type_comparison(
                         ops,
                         comparators,
-                        expr.location,
+                        self.locate_check(expr.location),
                     ));
                 }
             }
@@ -917,9 +970,10 @@ where
                 match name {
                     Some(name) => {
                         if self.settings.select.contains(&CheckCode::E741) {
-                            if let Some(check) =
-                                checks::check_ambiguous_variable_name(name, excepthandler.location)
-                            {
+                            if let Some(check) = checks::check_ambiguous_variable_name(
+                                name,
+                                self.locate_check(excepthandler.location),
+                            ) {
                                 self.checks.push(check);
                             }
                         }
@@ -1019,14 +1073,22 @@ where
         );
 
         if self.settings.select.contains(&CheckCode::E741) {
-            if let Some(check) = checks::check_ambiguous_variable_name(&arg.node.arg, arg.location)
-            {
+            if let Some(check) = checks::check_ambiguous_variable_name(
+                &arg.node.arg,
+                self.locate_check(arg.location),
+            ) {
                 self.checks.push(check);
             }
         }
     }
 }
 
+impl CheckLocator for Checker<'_> {
+    fn locate_check(&self, default: Location) -> Location {
+        self.in_f_string.unwrap_or(default)
+    }
+}
+
 impl<'a> Checker<'a> {
     fn push_parent(&mut self, parent: &'a Stmt) {
         self.parent_stack.push(self.parents.len());
@@ -1083,12 +1145,24 @@ impl<'a> Checker<'a> {
         // TODO(charlie): Don't treat annotations as assignments if there is an existing value.
         let binding = match scope.values.get(&name) {
             None => binding,
-            Some(existing) => Binding {
-                kind: binding.kind,
-                location: binding.location,
-                used: existing.used,
-            },
+            Some(existing) => {
+                if self.settings.select.contains(&CheckCode::F402)
+                    && matches!(existing.kind, BindingKind::Importation(_))
+                    && matches!(binding.kind, BindingKind::LoopVar)
+                {
+                    self.checks.push(Check::new(
+                        CheckKind::ImportShadowedByLoopVar(name.clone(), existing.location.row()),
+                        binding.location,
+                    ));
+                }
+                Binding {
+                    kind: binding.kind,
+                    location: binding.location,
+                    used: existing.used,
+                }
+            }
         };
+
         scope.values.insert(name, binding);
     }
 
@@ -1099,6 +1173,7 @@ impl<'a> Checker<'a> {
 
             let mut first_iter = true;
             let mut in_generator = false;
+            let mut import_starred = false;
             for scope_index in self.scope_stack.iter().rev() {
                 let scope = &mut self.scopes[*scope_index];
                 if matches!(scope.kind, ScopeKind::Class) {
@@ -1115,6 +1190,28 @@ impl<'a> Checker<'a> {
 
                 first_iter = false;
                 in_generator = matches!(scope.kind, ScopeKind::Generator);
+                import_starred = import_starred || scope.import_starred;
+            }
+
+            if import_starred {
+                if self.settings.select.contains(&CheckCode::F405) {
+                    let mut from_list = vec![];
+                    for scope_index in self.scope_stack.iter().rev() {
+                        let scope = &self.scopes[*scope_index];
+                        for (name, binding) in scope.values.iter() {
+                            if matches!(binding.kind, BindingKind::StarImportation) {
+                                from_list.push(name.as_str());
+                            }
+                        }
+                    }
+                    from_list.sort();
+
+                    self.checks.push(Check::new(
+                        CheckKind::ImportStarUsage(id.clone(), from_list.join(", ")),
+                        self.locate_check(expr.location),
+                    ));
+                }
+                return;
             }
 
             if self.settings.select.contains(&CheckCode::F821) {
@@ -1124,7 +1221,7 @@ impl<'a> Checker<'a> {
                 }
                 self.checks.push(Check::new(
                     CheckKind::UndefinedName(id.clone()),
-                    expr.location,
+                    self.locate_check(expr.location),
                 ))
             }
         }
@@ -1136,17 +1233,17 @@ impl<'a> Checker<'a> {
                 &self.scopes[*(self.scope_stack.last().expect("No current scope found."))];
 
             if self.settings.select.contains(&CheckCode::F823)
-                && matches!(current.kind, ScopeKind::Function)
+                && matches!(current.kind, ScopeKind::Function(_))
                 && !current.values.contains_key(id)
             {
                 for scope in self.scopes.iter().rev().skip(1) {
-                    if matches!(scope.kind, ScopeKind::Function | ScopeKind::Module) {
+                    if matches!(scope.kind, ScopeKind::Function(_) | ScopeKind::Module) {
                         if let Some(binding) = scope.values.get(id) {
                             if let Some((scope_id, location)) = binding.used {
                                 if scope_id == current.id {
                                     self.checks.push(Check::new(
                                         CheckKind::UndefinedLocal(id.clone()),
-                                        location,
+                                        self.locate_check(location),
                                     ));
                                 }
                             }
@@ -1171,8 +1268,19 @@ impl<'a> Checker<'a> {
             if matches!(
                 parent.node,
                 StmtKind::For { .. } | StmtKind::AsyncFor { .. }
-            ) || operations::is_unpacking_assignment(parent)
-            {
+            ) {
+                self.add_binding(
+                    id.to_string(),
+                    Binding {
+                        kind: BindingKind::LoopVar,
+                        used: None,
+                        location: expr.location,
+                    },
+                );
+                return;
+            }
+
+            if operations::is_unpacking_assignment(parent) {
                 self.add_binding(
                     id.to_string(),
                     Binding {
@@ -1228,7 +1336,7 @@ impl<'a> Checker<'a> {
             {
                 self.checks.push(Check::new(
                     CheckKind::UndefinedName(id.clone()),
-                    expr.location,
+                    self.locate_check(expr.location),
                 ))
             }
         }
@@ -1253,7 +1361,7 @@ impl<'a> Checker<'a> {
             } else if self.settings.select.contains(&CheckCode::F722) {
                 self.checks.push(Check::new(
                     CheckKind::ForwardAnnotationSyntaxError(expression.to_string()),
-                    location,
+                    self.locate_check(location),
                 ));
             }
         }
@@ -1266,7 +1374,7 @@ impl<'a> Checker<'a> {
         while let Some((stmt, scopes, parents)) = self.deferred_functions.pop() {
             self.parent_stack = parents;
             self.scope_stack = scopes;
-            self.push_scope(Scope::new(ScopeKind::Function));
+            self.push_scope(Scope::new(ScopeKind::Function(Default::default())));
 
             match &stmt.node {
                 StmtKind::FunctionDef { body, args, .. }
@@ -1290,7 +1398,7 @@ impl<'a> Checker<'a> {
         while let Some((expr, scopes, parents)) = self.deferred_lambdas.pop() {
             self.parent_stack = parents;
             self.scope_stack = scopes;
-            self.push_scope(Scope::new(ScopeKind::Function));
+            self.push_scope(Scope::new(ScopeKind::Function(Default::default())));
 
             if let ExprKind::Lambda { args, body } = &expr.node {
                 self.visit_arguments(args);
@@ -1305,17 +1413,18 @@ impl<'a> Checker<'a> {
     }
 
     fn check_deferred_assignments(&mut self) {
-        while let Some(index) = self.deferred_assignments.pop() {
-            if self.settings.select.contains(&CheckCode::F841) {
+        if self.settings.select.contains(&CheckCode::F841) {
+            while let Some(index) = self.deferred_assignments.pop() {
                 self.checks
-                    .extend(checks::check_unused_variables(&self.scopes[index]));
+                    .extend(checks::check_unused_variables(&self.scopes[index], self));
             }
         }
     }
 
     fn check_dead_scopes(&mut self) {
-        if !self.settings.select.contains(&CheckCode::F822)
-            && !self.settings.select.contains(&CheckCode::F401)
+        if !self.settings.select.contains(&CheckCode::F401)
+            && !self.settings.select.contains(&CheckCode::F405)
+            && !self.settings.select.contains(&CheckCode::F822)
         {
             return;
         }
@@ -1330,15 +1439,39 @@ impl<'a> Checker<'a> {
             });
 
             if self.settings.select.contains(&CheckCode::F822)
+                && !scope.import_starred
                 && !self.path.ends_with("__init__.py")
             {
-                if let Some(binding) = all_binding {
+                if let Some(all_binding) = all_binding {
                     if let Some(names) = all_names {
                         for name in names {
                             if !scope.values.contains_key(name) {
                                 self.checks.push(Check::new(
                                     CheckKind::UndefinedExport(name.to_string()),
-                                    binding.location,
+                                    self.locate_check(all_binding.location),
+                                ));
+                            }
+                        }
+                    }
+                }
+            }
+
+            if self.settings.select.contains(&CheckCode::F405) && scope.import_starred {
+                if let Some(all_binding) = all_binding {
+                    if let Some(names) = all_names {
+                        let mut from_list = vec![];
+                        for (name, binding) in scope.values.iter() {
+                            if matches!(binding.kind, BindingKind::StarImportation) {
+                                from_list.push(name.as_str());
+                            }
+                        }
+                        from_list.sort();
+
+                        for name in names {
+                            if !scope.values.contains_key(name) {
+                                self.checks.push(Check::new(
+                                    CheckKind::ImportStarUsage(name.clone(), from_list.join(", ")),
+                                    self.locate_check(all_binding.location),
                                 ));
                             }
                         }
@@ -1359,7 +1492,7 @@ impl<'a> Checker<'a> {
                             | BindingKind::SubmoduleImportation(full_name) => {
                                 self.checks.push(Check::new(
                                     CheckKind::UnusedImport(full_name.to_string()),
-                                    binding.location,
+                                    self.locate_check(binding.location),
                                 ));
                             }
                             _ => {}

src/check_lines.rs

@@ -35,7 +35,7 @@ pub fn check_lines(checks: &mut Vec<Check>, contents: &str, settings: &Settings)
 
         // Enforce line length.
         if enforce_line_too_long {
-            let line_length = line.len();
+            let line_length = line.chars().count();
             if should_enforce_line_length(line, line_length, settings.line_length) {
                 let check = Check::new(
                     CheckKind::LineTooLong(line_length, settings.line_length),
@@ -53,3 +53,31 @@ pub fn check_lines(checks: &mut Vec<Check>, contents: &str, settings: &Settings)
     }
     checks.extend(line_checks);
 }
+
+#[cfg(test)]
+mod tests {
+    use std::collections::BTreeSet;
+
+    use super::check_lines;
+    use super::*;
+
+    #[test]
+    fn e501_non_ascii_char() {
+        let line = "'\u{4e9c}' * 2"; // 7 in UTF-32, 9 in UTF-8.
+        let check_with_max_line_length = |line_length: usize| {
+            let mut checks: Vec<Check> = vec![];
+            let settings = Settings {
+                pyproject: None,
+                project_root: None,
+                line_length,
+                exclude: vec![],
+                extend_exclude: vec![],
+                select: BTreeSet::from_iter(vec![CheckCode::E501]),
+            };
+            check_lines(&mut checks, line, &settings);
+            return checks;
+        };
+        assert!(!check_with_max_line_length(6).is_empty());
+        assert!(check_with_max_line_length(7).is_empty());
+    }
+}

src/checks.rs

@@ -6,7 +6,54 @@ use regex::Regex;
 use rustpython_parser::ast::Location;
 use serde::{Deserialize, Serialize};
 
-#[derive(Debug, PartialEq, Eq, Serialize, Deserialize, Hash, PartialOrd, Ord)]
+pub const ALL_CHECK_CODES: [CheckCode; 44] = [
+    CheckCode::E402,
+    CheckCode::E501,
+    CheckCode::E711,
+    CheckCode::E712,
+    CheckCode::E713,
+    CheckCode::E714,
+    CheckCode::E721,
+    CheckCode::E722,
+    CheckCode::E731,
+    CheckCode::E741,
+    CheckCode::E742,
+    CheckCode::E743,
+    CheckCode::E902,
+    CheckCode::E999,
+    CheckCode::F401,
+    CheckCode::F402,
+    CheckCode::F403,
+    CheckCode::F404,
+    CheckCode::F405,
+    CheckCode::F406,
+    CheckCode::F407,
+    CheckCode::F541,
+    CheckCode::F601,
+    CheckCode::F602,
+    CheckCode::F621,
+    CheckCode::F622,
+    CheckCode::F631,
+    CheckCode::F632,
+    CheckCode::F633,
+    CheckCode::F634,
+    CheckCode::F701,
+    CheckCode::F702,
+    CheckCode::F704,
+    CheckCode::F706,
+    CheckCode::F707,
+    CheckCode::F722,
+    CheckCode::F821,
+    CheckCode::F822,
+    CheckCode::F823,
+    CheckCode::F831,
+    CheckCode::F841,
+    CheckCode::F901,
+    CheckCode::R001,
+    CheckCode::R002,
+];
+
+#[derive(Debug, PartialEq, Eq, Clone, Serialize, Deserialize, Hash, PartialOrd, Ord)]
 pub enum CheckCode {
     E402,
     E501,
@@ -23,8 +70,10 @@ pub enum CheckCode {
     E902,
     E999,
     F401,
+    F402,
     F403,
     F404,
+    F405,
     F406,
     F407,
     F541,
@@ -72,8 +121,10 @@ impl FromStr for CheckCode {
             "E902" => Ok(CheckCode::E902),
             "E999" => Ok(CheckCode::E999),
             "F401" => Ok(CheckCode::F401),
+            "F402" => Ok(CheckCode::F402),
             "F403" => Ok(CheckCode::F403),
             "F404" => Ok(CheckCode::F404),
+            "F405" => Ok(CheckCode::F405),
             "F406" => Ok(CheckCode::F406),
             "F407" => Ok(CheckCode::F407),
             "F541" => Ok(CheckCode::F541),
@@ -122,8 +173,10 @@ impl CheckCode {
             CheckCode::E902 => "E902",
             CheckCode::E999 => "E999",
             CheckCode::F401 => "F401",
+            CheckCode::F402 => "F402",
             CheckCode::F403 => "F403",
             CheckCode::F404 => "F404",
+            CheckCode::F405 => "F405",
             CheckCode::F406 => "F406",
             CheckCode::F407 => "F407",
             CheckCode::F541 => "F541",
@@ -160,6 +213,56 @@ impl CheckCode {
             _ => &LintSource::AST,
         }
     }
+
+    /// A placeholder representation of the CheckKind for the check.
+    pub fn kind(&self) -> CheckKind {
+        match self {
+            CheckCode::E402 => CheckKind::ModuleImportNotAtTopOfFile,
+            CheckCode::E501 => CheckKind::LineTooLong(89, 88),
+            CheckCode::E711 => CheckKind::NoneComparison(RejectedCmpop::Eq),
+            CheckCode::E712 => CheckKind::TrueFalseComparison(true, RejectedCmpop::Eq),
+            CheckCode::E713 => CheckKind::NotInTest,
+            CheckCode::E714 => CheckKind::NotIsTest,
+            CheckCode::E721 => CheckKind::TypeComparison,
+            CheckCode::E722 => CheckKind::DoNotUseBareExcept,
+            CheckCode::E731 => CheckKind::DoNotAssignLambda,
+            CheckCode::E741 => CheckKind::AmbiguousVariableName("...".to_string()),
+            CheckCode::E742 => CheckKind::AmbiguousClassName("...".to_string()),
+            CheckCode::E743 => CheckKind::AmbiguousFunctionName("...".to_string()),
+            CheckCode::E902 => CheckKind::IOError("...".to_string()),
+            CheckCode::E999 => CheckKind::SyntaxError("...".to_string()),
+            CheckCode::F401 => CheckKind::UnusedImport("...".to_string()),
+            CheckCode::F402 => CheckKind::ImportShadowedByLoopVar("...".to_string(), 1),
+            CheckCode::F403 => CheckKind::ImportStarUsed("...".to_string()),
+            CheckCode::F404 => CheckKind::LateFutureImport,
+            CheckCode::F405 => CheckKind::ImportStarUsage("...".to_string(), "...".to_string()),
+            CheckCode::F406 => CheckKind::ImportStarNotPermitted("...".to_string()),
+            CheckCode::F407 => CheckKind::FutureFeatureNotDefined("...".to_string()),
+            CheckCode::F541 => CheckKind::FStringMissingPlaceholders,
+            CheckCode::F601 => CheckKind::MultiValueRepeatedKeyLiteral,
+            CheckCode::F602 => CheckKind::MultiValueRepeatedKeyVariable("...".to_string()),
+            CheckCode::F621 => CheckKind::TooManyExpressionsInStarredAssignment,
+            CheckCode::F622 => CheckKind::TwoStarredExpressions,
+            CheckCode::F631 => CheckKind::AssertTuple,
+            CheckCode::F632 => CheckKind::IsLiteral,
+            CheckCode::F633 => CheckKind::InvalidPrintSyntax,
+            CheckCode::F634 => CheckKind::IfTuple,
+            CheckCode::F701 => CheckKind::BreakOutsideLoop,
+            CheckCode::F702 => CheckKind::ContinueOutsideLoop,
+            CheckCode::F704 => CheckKind::YieldOutsideFunction,
+            CheckCode::F706 => CheckKind::ReturnOutsideFunction,
+            CheckCode::F707 => CheckKind::DefaultExceptNotLast,
+            CheckCode::F722 => CheckKind::ForwardAnnotationSyntaxError("...".to_string()),
+            CheckCode::F821 => CheckKind::UndefinedName("...".to_string()),
+            CheckCode::F822 => CheckKind::UndefinedExport("...".to_string()),
+            CheckCode::F823 => CheckKind::UndefinedLocal("...".to_string()),
+            CheckCode::F831 => CheckKind::DuplicateArgumentName,
+            CheckCode::F841 => CheckKind::UnusedVariable("...".to_string()),
+            CheckCode::F901 => CheckKind::RaiseNotImplemented,
+            CheckCode::R001 => CheckKind::UselessObjectInheritance("...".to_string()),
+            CheckCode::R002 => CheckKind::NoAssertEquals,
+        }
+    }
 }
 
 #[allow(clippy::upper_case_acronyms)]
@@ -192,8 +295,10 @@ pub enum CheckKind {
     FutureFeatureNotDefined(String),
     IOError(String),
     IfTuple,
+    ImportShadowedByLoopVar(String, usize),
     ImportStarNotPermitted(String),
-    ImportStarUsage(String),
+    ImportStarUsage(String, String),
+    ImportStarUsed(String),
     InvalidPrintSyntax,
     IsLiteral,
     LateFutureImport,
@@ -240,8 +345,10 @@ impl CheckKind {
             CheckKind::FutureFeatureNotDefined(_) => "FutureFeatureNotDefined",
             CheckKind::IOError(_) => "IOError",
             CheckKind::IfTuple => "IfTuple",
+            CheckKind::ImportShadowedByLoopVar(_, _) => "ImportShadowedByLoopVar",
             CheckKind::ImportStarNotPermitted(_) => "ImportStarNotPermitted",
-            CheckKind::ImportStarUsage(_) => "ImportStarUsage",
+            CheckKind::ImportStarUsage(_, _) => "ImportStarUsage",
+            CheckKind::ImportStarUsed(_) => "ImportStarUsed",
             CheckKind::InvalidPrintSyntax => "InvalidPrintSyntax",
             CheckKind::IsLiteral => "IsLiteral",
             CheckKind::LateFutureImport => "LateFutureImport",
@@ -290,8 +397,10 @@ impl CheckKind {
             CheckKind::FutureFeatureNotDefined(_) => &CheckCode::F407,
             CheckKind::IOError(_) => &CheckCode::E902,
             CheckKind::IfTuple => &CheckCode::F634,
+            CheckKind::ImportShadowedByLoopVar(_, _) => &CheckCode::F402,
             CheckKind::ImportStarNotPermitted(_) => &CheckCode::F406,
-            CheckKind::ImportStarUsage(_) => &CheckCode::F403,
+            CheckKind::ImportStarUsed(_) => &CheckCode::F403,
+            CheckKind::ImportStarUsage(_, _) => &CheckCode::F405,
             CheckKind::InvalidPrintSyntax => &CheckCode::F633,
             CheckKind::IsLiteral => &CheckCode::F632,
             CheckKind::LateFutureImport => &CheckCode::F404,
@@ -356,17 +465,21 @@ impl CheckKind {
             CheckKind::FutureFeatureNotDefined(name) => {
                 format!("future feature '{name}' is not defined")
             }
-            CheckKind::IOError(name) => {
-                format!("No such file or directory: `{name}`")
-            }
+            CheckKind::IOError(message) => message.clone(),
             CheckKind::IfTuple => "If test is a tuple, which is always `True`".to_string(),
             CheckKind::InvalidPrintSyntax => "use of >> is invalid with print function".to_string(),
+            CheckKind::ImportShadowedByLoopVar(name, line) => {
+                format!("import '{name}' from line {line} shadowed by loop variable")
+            }
             CheckKind::ImportStarNotPermitted(name) => {
                 format!("`from {name} import *` only allowed at module level")
             }
-            CheckKind::ImportStarUsage(name) => {
+            CheckKind::ImportStarUsed(name) => {
                 format!("`from {name} import *` used; unable to detect undefined names")
             }
+            CheckKind::ImportStarUsage(name, sources) => {
+                format!("'{name}' may be undefined, or defined from star imports: {sources}")
+            }
             CheckKind::IsLiteral => "use ==/!= to compare constant literals".to_string(),
             CheckKind::LateFutureImport => {
                 "from __future__ imports must occur at the beginning of the file".to_string()

src/fs.rs

@@ -1,147 +0,0 @@
-use std::env;
-use std::fs::File;
-use std::io::{BufReader, Read};
-use std::path::{Path, PathBuf};
-
-use anyhow::Result;
-use glob::Pattern;
-use log::debug;
-use path_absolutize::Absolutize;
-use walkdir::{DirEntry, WalkDir};
-
-fn is_excluded(path: &Path, exclude: &[Pattern]) -> bool {
-    // Check the basename.
-    if let Some(file_name) = path.file_name() {
-        if let Some(file_name) = file_name.to_str() {
-            for pattern in exclude {
-                if pattern.matches(file_name) {
-                    return true;
-                }
-            }
-        }
-    }
-
-    // Check the complete path.
-    if let Some(file_name) = path.to_str() {
-        for pattern in exclude {
-            if pattern.matches(file_name) {
-                return true;
-            }
-        }
-    }
-
-    false
-}
-
-fn is_included(path: &Path) -> bool {
-    let file_name = path.to_string_lossy();
-    file_name.ends_with(".py") || file_name.ends_with(".pyi")
-}
-
-pub fn iter_python_files<'a>(
-    path: &'a PathBuf,
-    exclude: &'a [Pattern],
-    extend_exclude: &'a [Pattern],
-) -> impl Iterator<Item = DirEntry> + 'a {
-    WalkDir::new(normalize_path(path))
-        .follow_links(true)
-        .into_iter()
-        .filter_entry(|entry| {
-            if exclude.is_empty() && extend_exclude.is_empty() {
-                return true;
-            }
-
-            let path = entry.path();
-            if is_excluded(path, exclude) {
-                debug!("Ignored path via `exclude`: {:?}", path);
-                false
-            } else if is_excluded(path, extend_exclude) {
-                debug!("Ignored path via `extend-exclude`: {:?}", path);
-                false
-            } else {
-                true
-            }
-        })
-        .filter_map(|entry| entry.ok())
-        .filter(|entry| {
-            let path = entry.path();
-            is_included(path)
-        })
-}
-
-pub fn normalize_path(path: &PathBuf) -> PathBuf {
-    if path == Path::new(".") || path == Path::new("..") {
-        return path.clone();
-    }
-    if let Ok(path) = path.absolutize() {
-        if let Ok(root) = env::current_dir() {
-            if let Ok(path) = path.strip_prefix(root) {
-                return Path::new(".").join(path);
-            }
-        }
-    }
-    path.clone()
-}
-
-pub fn read_file(path: &Path) -> Result<String> {
-    let file = File::open(path)?;
-    let mut buf_reader = BufReader::new(file);
-    let mut contents = String::new();
-    buf_reader.read_to_string(&mut contents)?;
-    Ok(contents)
-}
-
-#[cfg(test)]
-mod tests {
-    use std::path::Path;
-
-    use glob::Pattern;
-
-    use crate::fs::{is_excluded, is_included};
-
-    #[test]
-    fn inclusions() {
-        let path = Path::new("foo/bar/baz.py");
-        assert!(is_included(path));
-
-        let path = Path::new("foo/bar/baz.pyi");
-        assert!(is_included(path));
-
-        let path = Path::new("foo/bar/baz.js");
-        assert!(!is_included(path));
-
-        let path = Path::new("foo/bar/baz");
-        assert!(!is_included(path));
-    }
-
-    #[test]
-    fn exclusions() {
-        let path = Path::new("foo");
-        let exclude = vec![Pattern::new("foo").unwrap()];
-        assert!(is_excluded(path, &exclude));
-
-        let path = Path::new("foo/bar");
-        let exclude = vec![Pattern::new("bar").unwrap()];
-        assert!(is_excluded(path, &exclude));
-
-        let path = Path::new("foo/bar/baz.py");
-        let exclude = vec![Pattern::new("baz.py").unwrap()];
-        assert!(is_excluded(path, &exclude));
-
-        let path = Path::new("foo/bar");
-        let exclude = vec![Pattern::new("foo/bar").unwrap()];
-        assert!(is_excluded(path, &exclude));
-
-        let path = Path::new("foo/bar/baz.py");
-        let exclude = vec![Pattern::new("foo/bar/baz.py").unwrap()];
-        assert!(is_excluded(path, &exclude));
-
-        let path = Path::new("foo/bar/baz.py");
-        let exclude = vec![Pattern::new("foo/bar/*.py").unwrap()];
-        assert!(is_excluded(path, &exclude));
-
-        let path = Path::new("foo/bar/baz.py");
-        let exclude = vec![Pattern::new("baz").unwrap()];
-        assert!(!is_excluded(path, &exclude));
-    }
-}

src/lib.rs

@@ -1,16 +1,73 @@
-extern crate core;
+use rustpython_parser::ast::Location;
+use std::path::Path;
+
+use rustpython_parser::parser;
+use wasm_bindgen::prelude::*;
+
+use crate::check_ast::check_ast;
+use crate::check_lines::check_lines;
+use crate::checks::{Check, CheckCode, CheckKind, ALL_CHECK_CODES};
+use crate::settings::Settings;
 
 mod ast;
 mod autofix;
-pub mod cache;
 pub mod check_ast;
 mod check_lines;
 pub mod checks;
-pub mod fs;
-pub mod linter;
-pub mod logging;
-pub mod message;
-pub mod printer;
-mod pyproject;
 mod python;
 pub mod settings;
+use serde::{Deserialize, Serialize};
+
+#[derive(Debug, PartialEq, Eq, Serialize, Deserialize)]
+struct Message {
+    code: CheckCode,
+    message: String,
+    location: Location,
+}
+
+#[wasm_bindgen]
+extern "C" {
+    pub fn alert(s: &str);
+}
+
+#[wasm_bindgen]
+pub fn check(contents: &str) -> String {
+    let settings = Settings::for_rules(ALL_CHECK_CODES.to_vec());
+    let autofix = autofix::fixer::Mode::None;
+
+    // Aggregate all checks.
+    let mut checks: Vec<Check> = vec![];
+
+    // Run the AST-based checks.
+    match parser::parse_program(contents, "<filename>") {
+        Ok(python_ast) => checks.extend(check_ast(
+            &python_ast,
+            contents,
+            &settings,
+            &autofix,
+            Path::new("<filename>"),
+        )),
+        Err(parse_error) => {
+            if settings.select.contains(&CheckCode::E999) {
+                checks.push(Check::new(
+                    CheckKind::SyntaxError(parse_error.error.to_string()),
+                    parse_error.location,
+                ))
+            }
+        }
+    }
+
+    // Run the lines-based checks.
+    check_lines(&mut checks, contents, &settings);
+
+    let messages: Vec<Message> = checks
+        .into_iter()
+        .map(|check| Message {
+            code: check.kind.code().clone(),
+            message: check.kind.body(),
+            location: check.location,
+        })
+        .collect();
+
+    serde_json::to_string(&messages).unwrap()
+}

src/linter.rs

@@ -1,799 +0,0 @@
-use std::path::Path;
-
-use anyhow::Result;
-use log::debug;
-use rustpython_parser::parser;
-
-use crate::autofix::fixer;
-use crate::autofix::fixer::fix_file;
-use crate::check_ast::check_ast;
-use crate::check_lines::check_lines;
-use crate::checks::{Check, LintSource};
-use crate::message::Message;
-use crate::settings::Settings;
-use crate::{cache, fs};
-
-fn check_path(
-    path: &Path,
-    contents: &str,
-    settings: &Settings,
-    autofix: &fixer::Mode,
-) -> Result<Vec<Check>> {
-    // Aggregate all checks.
-    let mut checks: Vec<Check> = vec![];
-
-    // Run the AST-based checks.
-    if settings
-        .select
-        .iter()
-        .any(|check_code| matches!(check_code.lint_source(), LintSource::AST))
-    {
-        let python_ast = parser::parse_program(contents, "<filename>")?;
-        checks.extend(check_ast(&python_ast, contents, settings, autofix, path));
-    }
-
-    // Run the lines-based checks.
-    check_lines(&mut checks, contents, settings);
-
-    Ok(checks)
-}
-
-pub fn lint_path(
-    path: &Path,
-    settings: &Settings,
-    mode: &cache::Mode,
-    autofix: &fixer::Mode,
-) -> Result<Vec<Message>> {
-    let metadata = path.metadata()?;
-
-    // Check the cache.
-    if let Some(messages) = cache::get(path, &metadata, settings, autofix, mode) {
-        debug!("Cache hit for: {}", path.to_string_lossy());
-        return Ok(messages);
-    }
-
-    // Read the file from disk.
-    let contents = fs::read_file(path)?;
-
-    // Generate checks.
-    let mut checks = check_path(path, &contents, settings, autofix)?;
-
-    // Apply autofix.
-    if matches!(autofix, fixer::Mode::Apply) {
-        fix_file(&mut checks, &contents, path)?;
-    };
-
-    // Convert to messages.
-    let messages: Vec<Message> = checks
-        .into_iter()
-        .map(|check| Message {
-            kind: check.kind,
-            fixed: check.fix.map(|fix| fix.applied).unwrap_or_default(),
-            location: check.location,
-            filename: path.to_string_lossy().to_string(),
-        })
-        .collect();
-    cache::set(path, &metadata, settings, autofix, &messages, mode);
-
-    Ok(messages)
-}
-
-#[cfg(test)]
-mod tests {
-    use std::collections::BTreeSet;
-    use std::path::Path;
-
-    use anyhow::Result;
-
-    use crate::autofix::fixer;
-    use crate::checks::{Check, CheckCode};
-    use crate::fs;
-    use crate::linter;
-    use crate::settings;
-
-    fn check_path(
-        path: &Path,
-        settings: &settings::Settings,
-        autofix: &fixer::Mode,
-    ) -> Result<Vec<Check>> {
-        let contents = fs::read_file(path)?;
-        linter::check_path(path, &contents, settings, autofix)
-    }
-
-    #[test]
-    fn e402() -> Result<()> {
-        let mut checks = check_path(
-            Path::new("./resources/test/fixtures/E402.py"),
-            &settings::Settings {
-                line_length: 88,
-                exclude: vec![],
-                extend_exclude: vec![],
-                select: BTreeSet::from([CheckCode::E402]),
-            },
-            &fixer::Mode::Generate,
-        )?;
-        checks.sort_by_key(|check| check.location);
-        insta::assert_yaml_snapshot!(checks);
-        Ok(())
-    }
-
-    #[test]
-    fn e501() -> Result<()> {
-        let mut checks = check_path(
-            Path::new("./resources/test/fixtures/E501.py"),
-            &settings::Settings {
-                line_length: 88,
-                exclude: vec![],
-                extend_exclude: vec![],
-                select: BTreeSet::from([CheckCode::E501]),
-            },
-            &fixer::Mode::Generate,
-        )?;
-        checks.sort_by_key(|check| check.location);
-        insta::assert_yaml_snapshot!(checks);
-        Ok(())
-    }
-
-    #[test]
-    fn e711() -> Result<()> {
-        let mut checks = check_path(
-            Path::new("./resources/test/fixtures/E711.py"),
-            &settings::Settings {
-                line_length: 88,
-                exclude: vec![],
-                extend_exclude: vec![],
-                select: BTreeSet::from([CheckCode::E711]),
-            },
-            &fixer::Mode::Generate,
-        )?;
-        checks.sort_by_key(|check| check.location);
-        insta::assert_yaml_snapshot!(checks);
-        Ok(())
-    }
-
-    #[test]
-    fn e712() -> Result<()> {
-        let mut checks = check_path(
-            Path::new("./resources/test/fixtures/E712.py"),
-            &settings::Settings {
-                line_length: 88,
-                exclude: vec![],
-                extend_exclude: vec![],
-                select: BTreeSet::from([CheckCode::E712]),
-            },
-            &fixer::Mode::Generate,
-        )?;
-        checks.sort_by_key(|check| check.location);
-        insta::assert_yaml_snapshot!(checks);
-        Ok(())
-    }
-
-    #[test]
-    fn e713() -> Result<()> {
-        let mut checks = check_path(
-            Path::new("./resources/test/fixtures/E713.py"),
-            &settings::Settings {
-                line_length: 88,
-                exclude: vec![],
-                extend_exclude: vec![],
-                select: BTreeSet::from([CheckCode::E713]),
-            },
-            &fixer::Mode::Generate,
-        )?;
-        checks.sort_by_key(|check| check.location);
-        insta::assert_yaml_snapshot!(checks);
-        Ok(())
-    }
-
-    #[test]
-    fn e721() -> Result<()> {
-        let mut checks = check_path(
-            Path::new("./resources/test/fixtures/E721.py"),
-            &settings::Settings {
-                line_length: 88,
-                exclude: vec![],
-                extend_exclude: vec![],
-                select: BTreeSet::from([CheckCode::E721]),
-            },
-            &fixer::Mode::Generate,
-        )?;
-        checks.sort_by_key(|check| check.location);
-        insta::assert_yaml_snapshot!(checks);
-        Ok(())
-    }
-
-    #[test]
-    fn e722() -> Result<()> {
-        let mut checks = check_path(
-            Path::new("./resources/test/fixtures/E722.py"),
-            &settings::Settings {
-                line_length: 88,
-                exclude: vec![],
-                extend_exclude: vec![],
-                select: BTreeSet::from([CheckCode::E722]),
-            },
-            &fixer::Mode::Generate,
-        )?;
-        checks.sort_by_key(|check| check.location);
-        insta::assert_yaml_snapshot!(checks);
-        Ok(())
-    }
-
-    #[test]
-    fn e714() -> Result<()> {
-        let mut checks = check_path(
-            Path::new("./resources/test/fixtures/E714.py"),
-            &settings::Settings {
-                line_length: 88,
-                exclude: vec![],
-                extend_exclude: vec![],
-                select: BTreeSet::from([CheckCode::E714]),
-            },
-            &fixer::Mode::Generate,
-        )?;
-        checks.sort_by_key(|check| check.location);
-        insta::assert_yaml_snapshot!(checks);
-        Ok(())
-    }
-
-    #[test]
-    fn e731() -> Result<()> {
-        let mut checks = check_path(
-            Path::new("./resources/test/fixtures/E731.py"),
-            &settings::Settings {
-                line_length: 88,
-                exclude: vec![],
-                extend_exclude: vec![],
-                select: BTreeSet::from([CheckCode::E731]),
-            },
-            &fixer::Mode::Generate,
-        )?;
-        checks.sort_by_key(|check| check.location);
-        insta::assert_yaml_snapshot!(checks);
-        Ok(())
-    }
-
-    #[test]
-    fn e741() -> Result<()> {
-        let mut checks = check_path(
-            Path::new("./resources/test/fixtures/E741.py"),
-            &settings::Settings {
-                line_length: 88,
-                exclude: vec![],
-                extend_exclude: vec![],
-                select: BTreeSet::from([CheckCode::E741]),
-            },
-            &fixer::Mode::Generate,
-        )?;
-        checks.sort_by_key(|check| check.location);
-        insta::assert_yaml_snapshot!(checks);
-        Ok(())
-    }
-
-    #[test]
-    fn e742() -> Result<()> {
-        let mut checks = check_path(
-            Path::new("./resources/test/fixtures/E742.py"),
-            &settings::Settings {
-                line_length: 88,
-                exclude: vec![],
-                extend_exclude: vec![],
-                select: BTreeSet::from([CheckCode::E742]),
-            },
-            &fixer::Mode::Generate,
-        )?;
-        checks.sort_by_key(|check| check.location);
-        insta::assert_yaml_snapshot!(checks);
-        Ok(())
-    }
-
-    #[test]
-    fn e743() -> Result<()> {
-        let mut checks = check_path(
-            Path::new("./resources/test/fixtures/E743.py"),
-            &settings::Settings {
-                line_length: 88,
-                exclude: vec![],
-                extend_exclude: vec![],
-                select: BTreeSet::from([CheckCode::E743]),
-            },
-            &fixer::Mode::Generate,
-        )?;
-        checks.sort_by_key(|check| check.location);
-        insta::assert_yaml_snapshot!(checks);
-        Ok(())
-    }
-
-    #[test]
-    fn f401() -> Result<()> {
-        let mut checks = check_path(
-            Path::new("./resources/test/fixtures/F401.py"),
-            &settings::Settings {
-                line_length: 88,
-                exclude: vec![],
-                extend_exclude: vec![],
-                select: BTreeSet::from([CheckCode::F401]),
-            },
-            &fixer::Mode::Generate,
-        )?;
-        checks.sort_by_key(|check| check.location);
-        insta::assert_yaml_snapshot!(checks);
-        Ok(())
-    }
-
-    #[test]
-    fn f403() -> Result<()> {
-        let mut checks = check_path(
-            Path::new("./resources/test/fixtures/F403.py"),
-            &settings::Settings {
-                line_length: 88,
-                exclude: vec![],
-                extend_exclude: vec![],
-                select: BTreeSet::from([CheckCode::F403]),
-            },
-            &fixer::Mode::Generate,
-        )?;
-        checks.sort_by_key(|check| check.location);
-        insta::assert_yaml_snapshot!(checks);
-        Ok(())
-    }
-
-    #[test]
-    fn f404() -> Result<()> {
-        let mut checks = check_path(
-            Path::new("./resources/test/fixtures/F404.py"),
-            &settings::Settings {
-                line_length: 88,
-                exclude: vec![],
-                extend_exclude: vec![],
-                select: BTreeSet::from([CheckCode::F404]),
-            },
-            &fixer::Mode::Generate,
-        )?;
-        checks.sort_by_key(|check| check.location);
-        insta::assert_yaml_snapshot!(checks);
-        Ok(())
-    }
-
-    #[test]
-    fn f406() -> Result<()> {
-        let mut checks = check_path(
-            Path::new("./resources/test/fixtures/F406.py"),
-            &settings::Settings {
-                line_length: 88,
-                exclude: vec![],
-                extend_exclude: vec![],
-                select: BTreeSet::from([CheckCode::F406]),
-            },
-            &fixer::Mode::Generate,
-        )?;
-        checks.sort_by_key(|check| check.location);
-        insta::assert_yaml_snapshot!(checks);
-        Ok(())
-    }
-
-    #[test]
-    fn f407() -> Result<()> {
-        let mut checks = check_path(
-            Path::new("./resources/test/fixtures/F407.py"),
-            &settings::Settings {
-                line_length: 88,
-                exclude: vec![],
-                extend_exclude: vec![],
-                select: BTreeSet::from([CheckCode::F407]),
-            },
-            &fixer::Mode::Generate,
-        )?;
-        checks.sort_by_key(|check| check.location);
-        insta::assert_yaml_snapshot!(checks);
-        Ok(())
-    }
-
-    #[test]
-    fn f541() -> Result<()> {
-        let mut checks = check_path(
-            Path::new("./resources/test/fixtures/F541.py"),
-            &settings::Settings {
-                line_length: 88,
-                exclude: vec![],
-                extend_exclude: vec![],
-                select: BTreeSet::from([CheckCode::F541]),
-            },
-            &fixer::Mode::Generate,
-        )?;
-        checks.sort_by_key(|check| check.location);
-        insta::assert_yaml_snapshot!(checks);
-        Ok(())
-    }
-
-    #[test]
-    fn f601() -> Result<()> {
-        let mut checks = check_path(
-            Path::new("./resources/test/fixtures/F601.py"),
-            &settings::Settings {
-                line_length: 88,
-                exclude: vec![],
-                extend_exclude: vec![],
-                select: BTreeSet::from([CheckCode::F601]),
-            },
-            &fixer::Mode::Generate,
-        )?;
-        checks.sort_by_key(|check| check.location);
-        insta::assert_yaml_snapshot!(checks);
-        Ok(())
-    }
-
-    #[test]
-    fn f602() -> Result<()> {
-        let mut checks = check_path(
-            Path::new("./resources/test/fixtures/F602.py"),
-            &settings::Settings {
-                line_length: 88,
-                exclude: vec![],
-                extend_exclude: vec![],
-                select: BTreeSet::from([CheckCode::F602]),
-            },
-            &fixer::Mode::Generate,
-        )?;
-        checks.sort_by_key(|check| check.location);
-        insta::assert_yaml_snapshot!(checks);
-        Ok(())
-    }
-
-    #[test]
-    fn f622() -> Result<()> {
-        let mut checks = check_path(
-            Path::new("./resources/test/fixtures/F622.py"),
-            &settings::Settings {
-                line_length: 88,
-                exclude: vec![],
-                extend_exclude: vec![],
-                select: BTreeSet::from([CheckCode::F622]),
-            },
-            &fixer::Mode::Generate,
-        )?;
-        checks.sort_by_key(|check| check.location);
-        insta::assert_yaml_snapshot!(checks);
-        Ok(())
-    }
-
-    #[test]
-    fn f631() -> Result<()> {
-        let mut checks = check_path(
-            Path::new("./resources/test/fixtures/F631.py"),
-            &settings::Settings {
-                line_length: 88,
-                exclude: vec![],
-                extend_exclude: vec![],
-                select: BTreeSet::from([CheckCode::F631]),
-            },
-            &fixer::Mode::Generate,
-        )?;
-        checks.sort_by_key(|check| check.location);
-        insta::assert_yaml_snapshot!(checks);
-        Ok(())
-    }
-
-    #[test]
-    fn f632() -> Result<()> {
-        let mut checks = check_path(
-            Path::new("./resources/test/fixtures/F632.py"),
-            &settings::Settings {
-                line_length: 88,
-                exclude: vec![],
-                extend_exclude: vec![],
-                select: BTreeSet::from([CheckCode::F632]),
-            },
-            &fixer::Mode::Generate,
-        )?;
-        checks.sort_by_key(|check| check.location);
-        insta::assert_yaml_snapshot!(checks);
-        Ok(())
-    }
-
-    #[test]
-    fn f633() -> Result<()> {
-        let mut checks = check_path(
-            Path::new("./resources/test/fixtures/F633.py"),
-            &settings::Settings {
-                line_length: 88,
-                exclude: vec![],
-                extend_exclude: vec![],
-                select: BTreeSet::from([CheckCode::F633]),
-            },
-            &fixer::Mode::Generate,
-        )?;
-        checks.sort_by_key(|check| check.location);
-        insta::assert_yaml_snapshot!(checks);
-        Ok(())
-    }
-
-    #[test]
-    fn f634() -> Result<()> {
-        let mut checks = check_path(
-            Path::new("./resources/test/fixtures/F634.py"),
-            &settings::Settings {
-                line_length: 88,
-                exclude: vec![],
-                extend_exclude: vec![],
-                select: BTreeSet::from([CheckCode::F634]),
-            },
-            &fixer::Mode::Generate,
-        )?;
-        checks.sort_by_key(|check| check.location);
-        insta::assert_yaml_snapshot!(checks);
-        Ok(())
-    }
-
-    #[test]
-    fn f701() -> Result<()> {
-        let mut checks = check_path(
-            Path::new("./resources/test/fixtures/F701.py"),
-            &settings::Settings {
-                line_length: 88,
-                exclude: vec![],
-                extend_exclude: vec![],
-                select: BTreeSet::from([CheckCode::F701]),
-            },
-            &fixer::Mode::Generate,
-        )?;
-        checks.sort_by_key(|check| check.location);
-        insta::assert_yaml_snapshot!(checks);
-        Ok(())
-    }
-
-    #[test]
-    fn f702() -> Result<()> {
-        let mut checks = check_path(
-            Path::new("./resources/test/fixtures/F702.py"),
-            &settings::Settings {
-                line_length: 88,
-                exclude: vec![],
-                extend_exclude: vec![],
-                select: BTreeSet::from([CheckCode::F702]),
-            },
-            &fixer::Mode::Generate,
-        )?;
-        checks.sort_by_key(|check| check.location);
-        insta::assert_yaml_snapshot!(checks);
-        Ok(())
-    }
-
-    #[test]
-    fn f704() -> Result<()> {
-        let mut checks = check_path(
-            Path::new("./resources/test/fixtures/F704.py"),
-            &settings::Settings {
-                line_length: 88,
-                exclude: vec![],
-                extend_exclude: vec![],
-                select: BTreeSet::from([CheckCode::F704]),
-            },
-            &fixer::Mode::Generate,
-        )?;
-        checks.sort_by_key(|check| check.location);
-        insta::assert_yaml_snapshot!(checks);
-        Ok(())
-    }
-
-    #[test]
-    fn f706() -> Result<()> {
-        let mut checks = check_path(
-            Path::new("./resources/test/fixtures/F706.py"),
-            &settings::Settings {
-                line_length: 88,
-                exclude: vec![],
-                extend_exclude: vec![],
-                select: BTreeSet::from([CheckCode::F706]),
-            },
-            &fixer::Mode::Generate,
-        )?;
-        checks.sort_by_key(|check| check.location);
-        insta::assert_yaml_snapshot!(checks);
-        Ok(())
-    }
-
-    #[test]
-    fn f707() -> Result<()> {
-        let mut checks = check_path(
-            Path::new("./resources/test/fixtures/F707.py"),
-            &settings::Settings {
-                line_length: 88,
-                exclude: vec![],
-                extend_exclude: vec![],
-                select: BTreeSet::from([CheckCode::F707]),
-            },
-            &fixer::Mode::Generate,
-        )?;
-        checks.sort_by_key(|check| check.location);
-        insta::assert_yaml_snapshot!(checks);
-        Ok(())
-    }
-
-    #[test]
-    fn f722() -> Result<()> {
-        let mut checks = check_path(
-            Path::new("./resources/test/fixtures/F722.py"),
-            &settings::Settings {
-                line_length: 88,
-                exclude: vec![],
-                extend_exclude: vec![],
-                select: BTreeSet::from([CheckCode::F722]),
-            },
-            &fixer::Mode::Generate,
-        )?;
-        checks.sort_by_key(|check| check.location);
-        insta::assert_yaml_snapshot!(checks);
-        Ok(())
-    }
-
-    #[test]
-    fn f821() -> Result<()> {
-        let mut checks = check_path(
-            Path::new("./resources/test/fixtures/F821.py"),
-            &settings::Settings {
-                line_length: 88,
-                exclude: vec![],
-                extend_exclude: vec![],
-                select: BTreeSet::from([CheckCode::F821]),
-            },
-            &fixer::Mode::Generate,
-        )?;
-        checks.sort_by_key(|check| check.location);
-        insta::assert_yaml_snapshot!(checks);
-        Ok(())
-    }
-
-    #[test]
-    fn f822() -> Result<()> {
-        let mut checks = check_path(
-            Path::new("./resources/test/fixtures/F822.py"),
-            &settings::Settings {
-                line_length: 88,
-                exclude: vec![],
-                extend_exclude: vec![],
-                select: BTreeSet::from([CheckCode::F822]),
-            },
-            &fixer::Mode::Generate,
-        )?;
-        checks.sort_by_key(|check| check.location);
-        insta::assert_yaml_snapshot!(checks);
-        Ok(())
-    }
-
-    #[test]
-    fn f823() -> Result<()> {
-        let mut checks = check_path(
-            Path::new("./resources/test/fixtures/F823.py"),
-            &settings::Settings {
-                line_length: 88,
-                exclude: vec![],
-                extend_exclude: vec![],
-                select: BTreeSet::from([CheckCode::F823]),
-            },
-            &fixer::Mode::Generate,
-        )?;
-        checks.sort_by_key(|check| check.location);
-        insta::assert_yaml_snapshot!(checks);
-        Ok(())
-    }
-
-    #[test]
-    fn f831() -> Result<()> {
-        let mut checks = check_path(
-            Path::new("./resources/test/fixtures/F831.py"),
-            &settings::Settings {
-                line_length: 88,
-                exclude: vec![],
-                extend_exclude: vec![],
-                select: BTreeSet::from([CheckCode::F831]),
-            },
-            &fixer::Mode::Generate,
-        )?;
-        checks.sort_by_key(|check| check.location);
-        insta::assert_yaml_snapshot!(checks);
-        Ok(())
-    }
-
-    #[test]
-    fn f841() -> Result<()> {
-        let mut checks = check_path(
-            Path::new("./resources/test/fixtures/F841.py"),
-            &settings::Settings {
-                line_length: 88,
-                exclude: vec![],
-                extend_exclude: vec![],
-                select: BTreeSet::from([CheckCode::F841]),
-            },
-            &fixer::Mode::Generate,
-        )?;
-        checks.sort_by_key(|check| check.location);
-        insta::assert_yaml_snapshot!(checks);
-        Ok(())
-    }
-
-    #[test]
-    fn f901() -> Result<()> {
-        let mut checks = check_path(
-            Path::new("./resources/test/fixtures/F901.py"),
-            &settings::Settings {
-                line_length: 88,
-                exclude: vec![],
-                extend_exclude: vec![],
-                select: BTreeSet::from([CheckCode::F901]),
-            },
-            &fixer::Mode::Generate,
-        )?;
-        checks.sort_by_key(|check| check.location);
-        insta::assert_yaml_snapshot!(checks);
-        Ok(())
-    }
-
-    #[test]
-    fn r001() -> Result<()> {
-        let mut checks = check_path(
-            Path::new("./resources/test/fixtures/R001.py"),
-            &settings::Settings {
-                line_length: 88,
-                exclude: vec![],
-                extend_exclude: vec![],
-                select: BTreeSet::from([CheckCode::R001]),
-            },
-            &fixer::Mode::Generate,
-        )?;
-        checks.sort_by_key(|check| check.location);
-        insta::assert_yaml_snapshot!(checks);
-        Ok(())
-    }
-
-    #[test]
-    fn r002() -> Result<()> {
-        let mut checks = check_path(
-            Path::new("./resources/test/fixtures/R002.py"),
-            &settings::Settings {
-                line_length: 88,
-                exclude: vec![],
-                extend_exclude: vec![],
-                select: BTreeSet::from([CheckCode::R002]),
-            },
-            &fixer::Mode::Generate,
-        )?;
-        checks.sort_by_key(|check| check.location);
-        insta::assert_yaml_snapshot!(checks);
-        Ok(())
-    }
-
-    #[test]
-    fn init() -> Result<()> {
-        let mut checks = check_path(
-            Path::new("./resources/test/fixtures/__init__.py"),
-            &settings::Settings {
-                line_length: 88,
-                exclude: vec![],
-                extend_exclude: vec![],
-                select: BTreeSet::from([CheckCode::F821, CheckCode::F822]),
-            },
-            &fixer::Mode::Generate,
-        )?;
-        checks.sort_by_key(|check| check.location);
-        insta::assert_yaml_snapshot!(checks);
-        Ok(())
-    }
-
-    #[test]
-    fn future_annotations() -> Result<()> {
-        let mut checks = check_path(
-            Path::new("./resources/test/fixtures/future_annotations.py"),
-            &settings::Settings {
-                line_length: 88,
-                exclude: vec![],
-                extend_exclude: vec![],
-                select: BTreeSet::from([CheckCode::F401, CheckCode::F821]),
-            },
-            &fixer::Mode::Generate,
-        )?;
-        checks.sort_by_key(|check| check.location);
-        insta::assert_yaml_snapshot!(checks);
-        Ok(())
-    }
-}

src/logging.rs

@@ -1,37 +0,0 @@
-use anyhow::Result;
-use fern;
-
-#[macro_export]
-macro_rules! tell_user {
-    ($($arg:tt)*) => {
-        println!(
-            "[{}] {}",
-            chrono::Local::now()
-                .format("%H:%M:%S %p")
-                .to_string()
-                .dimmed(),
-            format_args!($($arg)*)
-        )
-    }
-}
-
-pub fn set_up_logging(verbose: bool) -> Result<()> {
-    fern::Dispatch::new()
-        .format(|out, message, record| {
-            out.finish(format_args!(
-                "{}[{}][{}] {}",
-                chrono::Local::now().format("[%Y-%m-%d][%H:%M:%S]"),
-                record.target(),
-                record.level(),
-                message
-            ))
-        })
-        .level(if verbose {
-            log::LevelFilter::Debug
-        } else {
-            log::LevelFilter::Info
-        })
-        .chain(std::io::stdout())
-        .apply()
-        .map_err(|e| e.into())
-}

src/main.rs

@@ -1,239 +0,0 @@
-use std::path::PathBuf;
-use std::process::ExitCode;
-use std::sync::mpsc::channel;
-use std::time::Instant;
-
-use anyhow::Result;
-use clap::{Parser, ValueHint};
-use colored::Colorize;
-use glob::Pattern;
-use log::{debug, error};
-use notify::{raw_watcher, RecursiveMode, Watcher};
-use rayon::prelude::*;
-use walkdir::DirEntry;
-
-use ::ruff::cache;
-use ::ruff::checks::CheckCode;
-use ::ruff::checks::CheckKind;
-use ::ruff::fs::iter_python_files;
-use ::ruff::linter::lint_path;
-use ::ruff::logging::set_up_logging;
-use ::ruff::message::Message;
-use ::ruff::printer::{Printer, SerializationFormat};
-use ::ruff::settings::Settings;
-use ::ruff::tell_user;
-
-const CARGO_PKG_NAME: &str = env!("CARGO_PKG_NAME");
-const CARGO_PKG_VERSION: &str = env!("CARGO_PKG_VERSION");
-
-#[derive(Debug, Parser)]
-#[clap(name = format!("{CARGO_PKG_NAME} (v{CARGO_PKG_VERSION})"))]
-#[clap(about = "An extremely fast Python linter.", long_about = None)]
-struct Cli {
-    #[clap(parse(from_os_str), value_hint = ValueHint::AnyPath, required = true)]
-    files: Vec<PathBuf>,
-    /// Enable verbose logging.
-    #[clap(short, long, action)]
-    verbose: bool,
-    /// Disable all logging (but still exit with status code "1" upon detecting errors).
-    #[clap(short, long, action)]
-    quiet: bool,
-    /// Exit with status code "0", even upon detecting errors.
-    #[clap(short, long, action)]
-    exit_zero: bool,
-    /// Run in watch mode by re-running whenever files change.
-    #[clap(short, long, action)]
-    watch: bool,
-    /// Attempt to automatically fix lint errors.
-    #[clap(short, long, action)]
-    fix: bool,
-    /// Disable cache reads.
-    #[clap(short, long, action)]
-    no_cache: bool,
-    /// List of error codes to enable.
-    #[clap(long, multiple = true)]
-    select: Vec<CheckCode>,
-    /// List of error codes to ignore.
-    #[clap(long, multiple = true)]
-    ignore: Vec<CheckCode>,
-    /// List of paths, used to exclude files and/or directories from checks.
-    #[clap(long, multiple = true)]
-    exclude: Vec<Pattern>,
-    /// Like --exclude, but adds additional files and directories on top of the excluded ones.
-    #[clap(long, multiple = true)]
-    extend_exclude: Vec<Pattern>,
-    /// Output serialization format for error messages.
-    #[clap(long, arg_enum, default_value_t=SerializationFormat::Text)]
-    format: SerializationFormat,
-}
-
-#[cfg(feature = "update-informer")]
-fn check_for_updates() {
-    use update_informer::{registry, Check};
-
-    let informer = update_informer::new(registry::PyPI, CARGO_PKG_NAME, CARGO_PKG_VERSION);
-
-    if let Some(new_version) = informer.check_version().ok().flatten() {
-        let msg = format!(
-            "A new version of {pkg_name} is available: v{pkg_version} -> {new_version}",
-            pkg_name = CARGO_PKG_NAME.italic().cyan(),
-            pkg_version = CARGO_PKG_VERSION,
-            new_version = new_version.to_string().green()
-        );
-
-        let cmd = format!(
-            "Run to update: {cmd} {pkg_name}",
-            cmd = "pip3 install --upgrade".green(),
-            pkg_name = CARGO_PKG_NAME.green()
-        );
-
-        println!("\n{msg}\n{cmd}");
-    }
-}
-
-fn run_once(
-    files: &[PathBuf],
-    settings: &Settings,
-    cache: bool,
-    autofix: bool,
-) -> Result<Vec<Message>> {
-    // Collect all the files to check.
-    let start = Instant::now();
-    let paths: Vec<DirEntry> = files
-        .iter()
-        .flat_map(|path| iter_python_files(path, &settings.exclude, &settings.extend_exclude))
-        .collect();
-    let duration = start.elapsed();
-    debug!("Identified files to lint in: {:?}", duration);
-
-    let start = Instant::now();
-    let mut messages: Vec<Message> = paths
-        .par_iter()
-        .map(|entry| {
-            lint_path(entry.path(), settings, &cache.into(), &autofix.into()).unwrap_or_else(|e| {
-                if settings.select.contains(&CheckCode::E999) {
-                    vec![Message {
-                        kind: CheckKind::SyntaxError(e.to_string()),
-                        fixed: false,
-                        location: Default::default(),
-                        filename: entry.path().to_string_lossy().to_string(),
-                    }]
-                } else {
-                    error!("Failed to check {}: {e:?}", entry.path().to_string_lossy());
-                    vec![]
-                }
-            })
-        })
-        .flatten()
-        .collect();
-
-    if settings.select.contains(&CheckCode::E902) {
-        for file in files {
-            if !file.exists() {
-                messages.push(Message {
-                    kind: CheckKind::IOError(file.to_string_lossy().to_string()),
-                    fixed: false,
-                    location: Default::default(),
-                    filename: file.to_string_lossy().to_string(),
-                })
-            }
-        }
-    }
-
-    messages.sort_unstable();
-    let duration = start.elapsed();
-    debug!("Checked files in: {:?}", duration);
-
-    Ok(messages)
-}
-
-fn inner_main() -> Result<ExitCode> {
-    let cli = Cli::parse();
-
-    set_up_logging(cli.verbose)?;
-
-    let mut settings = Settings::from_paths(&cli.files);
-
-    let mut printer = Printer::new(cli.format);
-
-    if !cli.select.is_empty() {
-        settings.select(cli.select);
-    }
-    if !cli.ignore.is_empty() {
-        settings.ignore(&cli.ignore);
-    }
-    if !cli.exclude.is_empty() {
-        settings.exclude = cli.exclude;
-    }
-    if !cli.extend_exclude.is_empty() {
-        settings.extend_exclude = cli.extend_exclude;
-    }
-
-    cache::init()?;
-
-    if cli.watch {
-        if cli.fix {
-            println!("Warning: --fix is not enabled in watch mode.");
-        }
-
-        if cli.format != SerializationFormat::Text {
-            println!("Warning: --format 'text' is used in watch mode.");
-        }
-
-        // Perform an initial run instantly.
-        printer.clear_screen()?;
-        tell_user!("Starting linter in watch mode...\n");
-
-        let messages = run_once(&cli.files, &settings, !cli.no_cache, false)?;
-        if !cli.quiet {
-            printer.write_continuously(&messages)?;
-        }
-
-        // Configure the file watcher.
-        let (tx, rx) = channel();
-        let mut watcher = raw_watcher(tx)?;
-        for file in &cli.files {
-            watcher.watch(file, RecursiveMode::Recursive)?;
-        }
-
-        loop {
-            match rx.recv() {
-                Ok(e) => {
-                    if let Some(path) = e.path {
-                        if path.to_string_lossy().ends_with(".py") {
-                            printer.clear_screen()?;
-                            tell_user!("File change detected...\n");
-
-                            let messages = run_once(&cli.files, &settings, !cli.no_cache, false)?;
-                            if !cli.quiet {
-                                printer.write_continuously(&messages)?;
-                            }
-                        }
-                    }
-                }
-                Err(e) => return Err(e.into()),
-            }
-        }
-    } else {
-        let messages = run_once(&cli.files, &settings, !cli.no_cache, cli.fix)?;
-        if !cli.quiet {
-            printer.write_once(&messages)?;
-        }
-
-        #[cfg(feature = "update-informer")]
-        check_for_updates();
-
-        if !messages.is_empty() && !cli.exit_zero {
-            return Ok(ExitCode::FAILURE);
-        }
-    }
-
-    Ok(ExitCode::SUCCESS)
-}
-
-fn main() -> ExitCode {
-    match inner_main() {
-        Ok(code) => code,
-        Err(_) => ExitCode::FAILURE,
-    }
-}

src/message.rs

@@ -1,49 +0,0 @@
-use std::cmp::Ordering;
-use std::fmt;
-
-use colored::Colorize;
-use rustpython_parser::ast::Location;
-use serde::{Deserialize, Serialize};
-
-use crate::checks::CheckKind;
-
-#[derive(Debug, PartialEq, Eq, Serialize, Deserialize)]
-pub struct Message {
-    pub kind: CheckKind,
-    pub fixed: bool,
-    pub location: Location,
-    pub filename: String,
-}
-
-impl Ord for Message {
-    fn cmp(&self, other: &Self) -> Ordering {
-        (&self.filename, self.location.row(), self.location.column()).cmp(&(
-            &other.filename,
-            other.location.row(),
-            other.location.column(),
-        ))
-    }
-}
-
-impl PartialOrd for Message {
-    fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
-        Some(self.cmp(other))
-    }
-}
-
-impl fmt::Display for Message {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        write!(
-            f,
-            "{}{}{}{}{}{} {} {}",
-            self.filename.white().bold(),
-            ":".cyan(),
-            self.location.row(),
-            ":".cyan(),
-            self.location.column(),
-            ":".cyan(),
-            self.kind.code().as_str().red().bold(),
-            self.kind.body()
-        )
-    }
-}

src/printer.rs

@@ -1,80 +0,0 @@
-use colored::Colorize;
-
-use anyhow::Result;
-use clap::ValueEnum;
-
-use crate::message::Message;
-use crate::tell_user;
-
-#[derive(Clone, Copy, ValueEnum, PartialEq, Eq, Debug)]
-pub enum SerializationFormat {
-    Text,
-    Json,
-}
-
-pub struct Printer {
-    format: SerializationFormat,
-}
-
-impl Printer {
-    pub fn new(format: SerializationFormat) -> Self {
-        Self { format }
-    }
-
-    pub fn write_once(&mut self, messages: &[Message]) -> Result<()> {
-        let (fixed, outstanding): (Vec<&Message>, Vec<&Message>) =
-            messages.iter().partition(|message| message.fixed);
-        let num_fixable = outstanding
-            .iter()
-            .filter(|message| message.kind.fixable())
-            .count();
-
-        match self.format {
-            SerializationFormat::Json => {
-                println!("{}", serde_json::to_string_pretty(&messages)?)
-            }
-            SerializationFormat::Text => {
-                if !fixed.is_empty() {
-                    println!(
-                        "Found {} error(s) ({} fixed).",
-                        outstanding.len(),
-                        fixed.len()
-                    )
-                } else {
-                    println!("Found {} error(s).", outstanding.len())
-                }
-
-                for message in outstanding {
-                    println!("{}", message)
-                }
-
-                if num_fixable > 0 {
-                    println!("{num_fixable} potentially fixable with the --fix option.")
-                }
-            }
-        }
-
-        Ok(())
-    }
-
-    pub fn write_continuously(&mut self, messages: &[Message]) -> Result<()> {
-        tell_user!(
-            "Found {} error(s). Watching for file changes.",
-            messages.len(),
-        );
-
-        if !messages.is_empty() {
-            println!();
-            for message in messages {
-                println!("{}", message)
-            }
-        }
-
-        Ok(())
-    }
-
-    pub fn clear_screen(&mut self) -> Result<()> {
-        clearscreen::clear()?;
-        Ok(())
-    }
-}

src/pyproject.rs

@@ -1,317 +0,0 @@
-use std::path::{Path, PathBuf};
-
-use anyhow::Result;
-use common_path::common_path_all;
-use log::debug;
-use serde::Deserialize;
-
-use crate::checks::CheckCode;
-use crate::fs;
-
-pub fn load_config(paths: &[PathBuf]) -> Config {
-    match find_project_root(paths) {
-        Some(project_root) => match find_pyproject_toml(&project_root) {
-            Some(path) => {
-                debug!("Found pyproject.toml at: {:?}", path);
-                match parse_pyproject_toml(&path) {
-                    Ok(pyproject) => pyproject
-                        .tool
-                        .and_then(|tool| tool.ruff)
-                        .unwrap_or_default(),
-                    Err(e) => {
-                        println!("Failed to load pyproject.toml: {:?}", e);
-                        println!("Falling back to default configuration...");
-                        Default::default()
-                    }
-                }
-            }
-            None => Default::default(),
-        },
-        None => Default::default(),
-    }
-}
-
-#[derive(Debug, PartialEq, Eq, Deserialize, Default)]
-#[serde(deny_unknown_fields, rename_all = "kebab-case")]
-pub struct Config {
-    pub line_length: Option<usize>,
-    pub exclude: Option<Vec<PathBuf>>,
-    pub extend_exclude: Option<Vec<PathBuf>>,
-    pub select: Option<Vec<CheckCode>>,
-    pub ignore: Option<Vec<CheckCode>>,
-}
-
-#[derive(Debug, PartialEq, Eq, Deserialize)]
-struct Tools {
-    ruff: Option<Config>,
-}
-
-#[derive(Debug, PartialEq, Eq, Deserialize)]
-struct PyProject {
-    tool: Option<Tools>,
-}
-
-fn parse_pyproject_toml(path: &Path) -> Result<PyProject> {
-    let contents = fs::read_file(path)?;
-    toml::from_str(&contents).map_err(|e| e.into())
-}
-
-fn find_pyproject_toml(path: &Path) -> Option<PathBuf> {
-    let path_pyproject_toml = path.join("pyproject.toml");
-    if path_pyproject_toml.is_file() {
-        return Some(path_pyproject_toml);
-    }
-    find_user_pyproject_toml()
-}
-
-fn find_user_pyproject_toml() -> Option<PathBuf> {
-    dirs::home_dir().map(|path| path.join(".ruff"))
-}
-
-fn find_project_root(sources: &[PathBuf]) -> Option<PathBuf> {
-    if let Some(prefix) = common_path_all(sources.iter().map(PathBuf::as_path)) {
-        for directory in prefix.ancestors() {
-            if directory.join(".git").is_dir() {
-                return Some(directory.to_path_buf());
-            }
-            if directory.join(".hg").is_dir() {
-                return Some(directory.to_path_buf());
-            }
-            if directory.join("pyproject.toml").is_file() {
-                return Some(directory.to_path_buf());
-            }
-        }
-    }
-
-    None
-}
-
-#[cfg(test)]
-mod tests {
-    use std::path::{Path, PathBuf};
-
-    use anyhow::Result;
-
-    use crate::checks::CheckCode;
-    use crate::pyproject::{
-        find_project_root, find_pyproject_toml, parse_pyproject_toml, Config, PyProject, Tools,
-    };
-
-    #[test]
-    fn deserialize() -> Result<()> {
-        let pyproject: PyProject = toml::from_str(r#""#)?;
-        assert_eq!(pyproject.tool, None);
-
-        let pyproject: PyProject = toml::from_str(
-            r#"
-[tool.black]
-"#,
-        )?;
-        assert_eq!(pyproject.tool, Some(Tools { ruff: None }));
-
-        let pyproject: PyProject = toml::from_str(
-            r#"
-[tool.black]
-[tool.ruff]
-"#,
-        )?;
-        assert_eq!(
-            pyproject.tool,
-            Some(Tools {
-                ruff: Some(Config {
-                    line_length: None,
-                    exclude: None,
-                    extend_exclude: None,
-                    select: None,
-                    ignore: None,
-                })
-            })
-        );
-
-        let pyproject: PyProject = toml::from_str(
-            r#"
-[tool.black]
-[tool.ruff]
-line-length = 79
-"#,
-        )?;
-        assert_eq!(
-            pyproject.tool,
-            Some(Tools {
-                ruff: Some(Config {
-                    line_length: Some(79),
-                    exclude: None,
-                    extend_exclude: None,
-                    select: None,
-                    ignore: None,
-                })
-            })
-        );
-
-        let pyproject: PyProject = toml::from_str(
-            r#"
-[tool.black]
-[tool.ruff]
-exclude = ["foo.py"]
-"#,
-        )?;
-        assert_eq!(
-            pyproject.tool,
-            Some(Tools {
-                ruff: Some(Config {
-                    line_length: None,
-                    exclude: Some(vec![Path::new("foo.py").to_path_buf()]),
-                    extend_exclude: None,
-                    select: None,
-                    ignore: None,
-                })
-            })
-        );
-
-        let pyproject: PyProject = toml::from_str(
-            r#"
-[tool.black]
-[tool.ruff]
-select = ["E501"]
-"#,
-        )?;
-        assert_eq!(
-            pyproject.tool,
-            Some(Tools {
-                ruff: Some(Config {
-                    line_length: None,
-                    exclude: None,
-                    extend_exclude: None,
-                    select: Some(vec![CheckCode::E501]),
-                    ignore: None,
-                })
-            })
-        );
-
-        let pyproject: PyProject = toml::from_str(
-            r#"
-[tool.black]
-[tool.ruff]
-ignore = ["E501"]
-"#,
-        )?;
-        assert_eq!(
-            pyproject.tool,
-            Some(Tools {
-                ruff: Some(Config {
-                    line_length: None,
-                    exclude: None,
-                    extend_exclude: None,
-                    select: None,
-                    ignore: Some(vec![CheckCode::E501]),
-                })
-            })
-        );
-
-        assert!(toml::from_str::<PyProject>(
-            r#"
-[tool.black]
-[tool.ruff]
-line_length = 79
-"#,
-        )
-        .is_err());
-
-        assert!(toml::from_str::<PyProject>(
-            r#"
-[tool.black]
-[tool.ruff]
-select = ["E123"]
-"#,
-        )
-        .is_err());
-
-        assert!(toml::from_str::<PyProject>(
-            r#"
-[tool.black]
-[tool.ruff]
-line-length = 79
-other-attribute = 1
-"#,
-        )
-        .is_err());
-
-        Ok(())
-    }
-
-    #[test]
-    fn find_and_parse_pyproject_toml() -> Result<()> {
-        let project_root =
-            find_project_root(&[PathBuf::from("resources/test/fixtures/__init__.py")])
-                .expect("Unable to find project root.");
-        assert_eq!(project_root, Path::new("resources/test/fixtures"));
-
-        let path = find_pyproject_toml(&project_root).expect("Unable to find pyproject.toml.");
-        assert_eq!(path, Path::new("resources/test/fixtures/pyproject.toml"));
-
-        let pyproject = parse_pyproject_toml(&path)?;
-        let config = pyproject
-            .tool
-            .and_then(|tool| tool.ruff)
-            .expect("Unable to find tool.ruff.");
-        assert_eq!(
-            config,
-            Config {
-                line_length: Some(88),
-                exclude: None,
-                extend_exclude: Some(vec![
-                    Path::new("excluded.py").to_path_buf(),
-                    Path::new("migrations").to_path_buf(),
-                    Path::new("./resources/test/fixtures/directory/also_excluded.py").to_path_buf()
-                ]),
-                select: Some(vec![
-                    CheckCode::E402,
-                    CheckCode::E501,
-                    CheckCode::E711,
-                    CheckCode::E712,
-                    CheckCode::E713,
-                    CheckCode::E714,
-                    CheckCode::E721,
-                    CheckCode::E722,
-                    CheckCode::E731,
-                    CheckCode::E741,
-                    CheckCode::E742,
-                    CheckCode::E743,
-                    CheckCode::E902,
-                    CheckCode::E999,
-                    CheckCode::F401,
-                    CheckCode::F403,
-                    CheckCode::F404,
-                    CheckCode::F406,
-                    CheckCode::F407,
-                    CheckCode::F541,
-                    CheckCode::F601,
-                    CheckCode::F602,
-                    CheckCode::F621,
-                    CheckCode::F622,
-                    CheckCode::F631,
-                    CheckCode::F632,
-                    CheckCode::F633,
-                    CheckCode::F634,
-                    CheckCode::F701,
-                    CheckCode::F702,
-                    CheckCode::F704,
-                    CheckCode::F706,
-                    CheckCode::F707,
-                    CheckCode::F722,
-                    CheckCode::F821,
-                    CheckCode::F822,
-                    CheckCode::F823,
-                    CheckCode::F831,
-                    CheckCode::F841,
-                    CheckCode::F901,
-                    CheckCode::R001,
-                    CheckCode::R002,
-                ]),
-                ignore: None,
-            }
-        );
-
-        Ok(())
-    }
-}

src/python/typing.rs

@@ -1,6 +1,7 @@
-use once_cell::sync::Lazy;
 use std::collections::BTreeSet;
 
+use once_cell::sync::Lazy;
+
 static ANNOTATED_SUBSCRIPTS: Lazy<BTreeSet<&'static str>> = Lazy::new(|| {
     BTreeSet::from([
         "AbstractAsyncContextManager",

src/settings.rs

@@ -1,21 +1,30 @@
 use std::collections::BTreeSet;
 use std::hash::{Hash, Hasher};
-use std::path::PathBuf;
-
-use glob::Pattern;
-use once_cell::sync::Lazy;
 
 use crate::checks::CheckCode;
-use crate::pyproject::load_config;
 
 #[derive(Debug)]
 pub struct Settings {
     pub line_length: usize,
-    pub exclude: Vec<Pattern>,
-    pub extend_exclude: Vec<Pattern>,
     pub select: BTreeSet<CheckCode>,
 }
 
+impl Settings {
+    pub fn for_rule(check_code: CheckCode) -> Self {
+        Self {
+            line_length: 88,
+            select: BTreeSet::from([check_code]),
+        }
+    }
+
+    pub fn for_rules(check_codes: Vec<CheckCode>) -> Self {
+        Self {
+            line_length: 88,
+            select: BTreeSet::from_iter(check_codes),
+        }
+    }
+}
+
 impl Hash for Settings {
     fn hash<H: Hasher>(&self, state: &mut H) {
         self.line_length.hash(state);
@@ -24,121 +33,3 @@ impl Hash for Settings {
         }
     }
 }
-
-static DEFAULT_EXCLUDE: Lazy<Vec<Pattern>> = Lazy::new(|| {
-    vec![
-        Pattern::new(".bzr").unwrap(),
-        Pattern::new(".direnv").unwrap(),
-        Pattern::new(".eggs").unwrap(),
-        Pattern::new(".git").unwrap(),
-        Pattern::new(".hg").unwrap(),
-        Pattern::new(".mypy_cache").unwrap(),
-        Pattern::new(".nox").unwrap(),
-        Pattern::new(".pants.d").unwrap(),
-        Pattern::new(".ruff_cache").unwrap(),
-        Pattern::new(".svn").unwrap(),
-        Pattern::new(".tox").unwrap(),
-        Pattern::new(".venv").unwrap(),
-        Pattern::new("__pypackages__").unwrap(),
-        Pattern::new("_build").unwrap(),
-        Pattern::new("buck-out").unwrap(),
-        Pattern::new("build").unwrap(),
-        Pattern::new("dist").unwrap(),
-        Pattern::new("node_modules").unwrap(),
-        Pattern::new("venv").unwrap(),
-    ]
-});
-
-impl Settings {
-    pub fn from_paths(paths: &[PathBuf]) -> Self {
-        let config = load_config(paths);
-        let mut settings = Settings {
-            line_length: config.line_length.unwrap_or(88),
-            exclude: config
-                .exclude
-                .map(|paths| {
-                    paths
-                        .iter()
-                        .map(|path| {
-                            Pattern::new(&path.to_string_lossy()).expect("Invalid pattern.")
-                        })
-                        .collect()
-                })
-                .unwrap_or_else(|| DEFAULT_EXCLUDE.clone()),
-            extend_exclude: config
-                .extend_exclude
-                .map(|paths| {
-                    paths
-                        .iter()
-                        .map(|path| {
-                            Pattern::new(&path.to_string_lossy()).expect("Invalid pattern.")
-                        })
-                        .collect()
-                })
-                .unwrap_or_default(),
-            select: BTreeSet::from_iter(config.select.unwrap_or_else(|| {
-                vec![
-                    CheckCode::E402,
-                    CheckCode::E501,
-                    CheckCode::E711,
-                    CheckCode::E712,
-                    CheckCode::E713,
-                    CheckCode::E714,
-                    CheckCode::E721,
-                    CheckCode::E722,
-                    CheckCode::E731,
-                    CheckCode::E741,
-                    CheckCode::E742,
-                    CheckCode::E743,
-                    CheckCode::E902,
-                    CheckCode::E999,
-                    CheckCode::F401,
-                    CheckCode::F403,
-                    CheckCode::F406,
-                    CheckCode::F407,
-                    CheckCode::F541,
-                    CheckCode::F601,
-                    CheckCode::F602,
-                    CheckCode::F621,
-                    CheckCode::F622,
-                    CheckCode::F631,
-                    CheckCode::F632,
-                    CheckCode::F633,
-                    CheckCode::F634,
-                    CheckCode::F701,
-                    CheckCode::F702,
-                    CheckCode::F704,
-                    CheckCode::F706,
-                    CheckCode::F707,
-                    CheckCode::F722,
-                    CheckCode::F821,
-                    CheckCode::F822,
-                    CheckCode::F823,
-                    CheckCode::F831,
-                    CheckCode::F841,
-                    CheckCode::F901,
-                    // Disable refactoring codes by default.
-                    // CheckCode::R001,
-                    // CheckCode::R002,
-                ]
-            })),
-        };
-        if let Some(ignore) = &config.ignore {
-            settings.ignore(ignore);
-        }
-        settings
-    }
-
-    pub fn select(&mut self, codes: Vec<CheckCode>) {
-        self.select.clear();
-        for code in codes {
-            self.select.insert(code);
-        }
-    }
-
-    pub fn ignore(&mut self, codes: &[CheckCode]) {
-        for code in codes {
-            self.select.remove(code);
-        }
-    }
-}

src/snapshots/ruff__linter__tests__f402.snap

@@ -0,0 +1,21 @@
+---
+source: src/linter.rs
+expression: checks
+---
+- kind:
+    ImportShadowedByLoopVar:
+      - os
+      - 1
+  location:
+    row: 5
+    column: 5
+  fix: ~
+- kind:
+    ImportShadowedByLoopVar:
+      - path
+      - 2
+  location:
+    row: 8
+    column: 5
+  fix: ~
+

src/snapshots/ruff__linter__tests__f403.snap

@@ -3,13 +3,13 @@ source: src/linter.rs
 expression: checks
 ---
 - kind:
-    ImportStarUsage: F634
+    ImportStarUsed: F634
   location:
     row: 1
     column: 1
   fix: ~
 - kind:
-    ImportStarUsage: F634
+    ImportStarUsed: F634
   location:
     row: 2
     column: 1

src/snapshots/ruff__linter__tests__f405.snap

@@ -0,0 +1,21 @@
+---
+source: src/linter.rs
+expression: checks
+---
+- kind:
+    ImportStarUsage:
+      - name
+      - mymodule
+  location:
+    row: 5
+    column: 11
+  fix: ~
+- kind:
+    ImportStarUsage:
+      - a
+      - mymodule
+  location:
+    row: 11
+    column: 1
+  fix: ~
+

src/snapshots/ruff__linter__tests__f821.snap

@@ -38,4 +38,16 @@ expression: checks
     row: 83
     column: 11
   fix: ~
+- kind:
+    UndefinedName: B
+  location:
+    row: 87
+    column: 7
+  fix: ~
+- kind:
+    UndefinedName: B
+  location:
+    row: 89
+    column: 7
+  fix: ~