Bump version to 0.0.45

.pre-commit-config.yaml

@@ -1,5 +1,5 @@
 repos:
-  - repo: https://github.com/charliermarsh/ruff
-    rev: v0.0.38
+  - 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.lock

@@ -1432,6 +1432,24 @@ dependencies = [
  "windows-sys",
 ]
 
+[[package]]
+name = "path-absolutize"
+version = "3.0.13"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d3de4b40bd9736640f14c438304c09538159802388febb02c8abaae0846c1f13"
+dependencies = [
+ "path-dedot",
+]
+
+[[package]]
+name = "path-dedot"
+version = "3.0.17"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d611d5291372b3738a34ebf0d1f849e58b1dcc1101032f76a346eaa1f8ddbb5b"
+dependencies = [
+ "once_cell",
+]
+
 [[package]]
 name = "percent-encoding"
 version = "2.1.0"
@@ -1783,7 +1801,7 @@ dependencies = [
 
 [[package]]
 name = "ruff"
-version = "0.0.38"
+version = "0.0.45"
 dependencies = [
  "anyhow",
  "bincode",
@@ -1802,6 +1820,7 @@ dependencies = [
  "log",
  "notify",
  "once_cell",
+ "path-absolutize",
  "rayon",
  "regex",
  "rustpython-parser",
@@ -1827,7 +1846,7 @@ dependencies = [
 [[package]]
 name = "rustpython-ast"
 version = "0.1.0"
-source = "git+https://github.com/charliermarsh/RustPython.git?rev=7d21c6923a506e79cc041708d83cef925efd33f4#7d21c6923a506e79cc041708d83cef925efd33f4"
+source = "git+https://github.com/charliermarsh/RustPython.git?rev=966a80597d626a9a47eaec78471164422d341453#966a80597d626a9a47eaec78471164422d341453"
 dependencies = [
  "num-bigint",
  "rustpython-compiler-core",
@@ -1836,7 +1855,7 @@ dependencies = [
 [[package]]
 name = "rustpython-compiler-core"
 version = "0.1.2"
-source = "git+https://github.com/charliermarsh/RustPython.git?rev=7d21c6923a506e79cc041708d83cef925efd33f4#7d21c6923a506e79cc041708d83cef925efd33f4"
+source = "git+https://github.com/charliermarsh/RustPython.git?rev=966a80597d626a9a47eaec78471164422d341453#966a80597d626a9a47eaec78471164422d341453"
 dependencies = [
  "bincode",
  "bitflags",
@@ -1853,7 +1872,7 @@ dependencies = [
 [[package]]
 name = "rustpython-parser"
 version = "0.1.2"
-source = "git+https://github.com/charliermarsh/RustPython.git?rev=7d21c6923a506e79cc041708d83cef925efd33f4#7d21c6923a506e79cc041708d83cef925efd33f4"
+source = "git+https://github.com/charliermarsh/RustPython.git?rev=966a80597d626a9a47eaec78471164422d341453#966a80597d626a9a47eaec78471164422d341453"
 dependencies = [
  "ahash",
  "anyhow",

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "ruff"
-version = "0.0.38"
+version = "0.0.45"
 edition = "2021"
 
 [lib]
@@ -18,14 +18,15 @@ 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 = { version = "3.0.13", features = ["once_cell_cache"] }
 rayon = { version = "1.5.3" }
 regex = { version = "1.6.0" }
-rustpython-parser = { features = ["lalrpop"], git = "https://github.com/charliermarsh/RustPython.git", rev = "7d21c6923a506e79cc041708d83cef925efd33f4" }
+rustpython-parser = { features = ["lalrpop"], git = "https://github.com/charliermarsh/RustPython.git", rev = "966a80597d626a9a47eaec78471164422d341453" }
 serde = { version = "1.0.143", features = ["derive"] }
 serde_json = { version = "1.0.83" }
 toml = { version = "0.5.9" }

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: v0.0.38
-  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 (v0.0.38)
+ruff (v0.0.45) 0.0.45
 An extremely fast Python linter.
 
 USAGE:
@@ -96,47 +96,121 @@ ARGS:
     <FILES>...
 
 OPTIONS:
-    -e, --exit-zero               Exit with status code "0", even upon detecting errors
-        --exclude <EXCLUDE>...    List of file and/or directory patterns to exclude from checks
-    -f, --fix                     Attempt to automatically fix lint errors
-    -h, --help                    Print help information
-        --ignore <IGNORE>...      List of error codes to ignore
-    -n, --no-cache                Disable cache reads
-    -q, --quiet                   Disable all logging (but still exit with status code "1" upon
-                                  detecting errors)
-        --select <SELECT>...      List of error codes to enable
-    -v, --verbose                 Enable verbose logging
-    -w, --watch                   Run in watch mode by re-running whenever files change
+        --select <SELECT>...
+            List of error codes to enable
+        --extend-select <EXTEND_SELECT>...
+            Like --select, but adds additional error codes on top of the selected ones
+        --ignore <IGNORE>...
+            List of error codes to ignore
+        --extend-ignore <EXTEND_IGNORE>...
+            Like --ignore, but adds additional error codes on top of the ignored ones
+        --exclude <EXCLUDE>...
+            List of paths, used to exclude files and/or directories from checks
+        --extend-exclude <EXTEND_EXCLUDE>...
+            Like --exclude, but adds additional files and directories on top of the excluded ones
+    -e, --exit-zero
+            Exit with status code "0", even upon detecting errors
+    -f, --fix
+            Attempt to automatically fix lint errors
+        --format <FORMAT>
+            Output serialization format for error messages [default: text] [possible values: text,
+            json]
+    -h, --help
+            Print help information
+    -n, --no-cache
+            Disable cache reads
+    -q, --quiet
+            Disable all logging (but still exit with status code "1" upon detecting errors)
+        --add-noqa
+            Enable automatic additions of noqa directives to failing lines
+        --show-files
+            See the files ruff will be run against with the current settings
+        --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
 ```
 
+### Excluding files
+
+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
+  project root (e.g., the directory containing your `pyproject.toml`).
+
+### Ignoring errors
+
+To omit a lint check entirely, add it to the "ignore" list via `--ignore` or `--extend-ignore`,
+either  on the command-line or in your `project.toml` file.
+
+To ignore an error in-line, ruff uses a `noqa` system similar to [Flake8](https://flake8.pycqa.org/en/3.1.1/user/ignoring-errors.html).
+To ignore an individual error, add `# noqa: {code}` to the end of the line, like so:
+
+```python
+# Ignore F841.
+x = 1  # noqa: F841
+
+# Ignore E741 and F841.
+i = 1  # noqa: E741, F841
+
+# Ignore _all_ errors.
+x = 1  # noqa
+```
+
+Note that, for multi-line strings, the `noqa` directive should come at the end of the string, and
+will apply to the entire body, like so:
+
+```python
+"""Lorem ipsum dolor sit amet.
+
+Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.
+"""  # noqa: E501
+```
+
+ruff supports several (experimental) workflows to aid in `noqa` management.
+
+First, ruff provides a special error code, `M001`, to enforce that your `noqa` directives are
+"valid", in that the errors they _say_ they ignore are actually being triggered on that line (and
+thus suppressed). **You can run `ruff /path/to/file.py --extend-select M001` to flag unused `noqa`
+directives.**
+
+Second, ruff can _automatically remove_ unused `noqa` directives via its autofix functionality.
+**You can run `ruff /path/to/file.py --extend-select M001 --fix` to automatically remove unused
+`noqa` directives.**
+
+Third, ruff can _automatically add_ `noqa` directives to all failing lines. This is useful when
+migrating a new codebase to ruff. **You can run `ruff /path/to/file.py --add-noqa` to automatically
+add `noqa` directives to all failing lines, with the appropriate error codes.**
+
 ### 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
@@ -155,11 +229,13 @@ 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 |
@@ -185,6 +261,7 @@ Beyond rule-set parity, ruff suffers from the following limitations vis-à-vis F
 | F901 | RaiseNotImplemented | `raise NotImplemented` should be `raise NotImplementedError` |
 | R001 | UselessObjectInheritance | Class `...` inherits from object |
 | R002 | NoAssertEquals | `assertEquals` is deprecated, use `assertEqual` instead |
+| M001 | UnusedNOQA | Unused `noqa` directive |
 
 ## Development
 
@@ -220,7 +297,7 @@ Add this `pyproject.toml` to the CPython directory:
 ```toml
 [tool.ruff]
 line-length = 88
-exclude = [
+extend-exclude = [
     "Lib/lib2to3/tests/data/bom.py",
     "Lib/lib2to3/tests/data/crlf.py",
     "Lib/lib2to3/tests/data/different_encoding.py",
@@ -251,17 +328,21 @@ 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:
@@ -273,11 +354,8 @@ 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:
@@ -287,66 +365,58 @@ 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

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(),

resources/test/fixtures/E501.py

@@ -4,3 +4,13 @@
 
 Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.
 """
+
+_ = """Lorem ipsum dolor sit amet.
+
+    https://github.com/PyCQA/pycodestyle/pull/258/files#diff-841c622497a8033d10152bfdfb15b20b92437ecdea21a260944ea86b77b51533
+
+Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.
+"""  # noqa: E501
+
+_ = "---------------------------------------------------------------------------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

@@ -77,3 +77,15 @@ class Ticket:
 
     def set_status(self, status: Status):
         self.status = status
+
+
+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/M001.py

@@ -0,0 +1,57 @@
+def f() -> None:
+    # Valid
+    a = 1  # noqa
+
+    # Valid
+    b = 2  # noqa: F841
+
+    # Invalid
+    c = 1  # noqa
+    print(c)
+
+    # Invalid
+    d = 1  # noqa: E501
+
+    # Invalid
+    d = 1  # noqa: F841, E501
+
+
+# Valid
+_ = """Lorem ipsum dolor sit amet.
+
+    https://github.com/PyCQA/pycodestyle/pull/258/files#diff-841c622497a8033d10152bfdfb15b20b92437ecdea21a260944ea86b77b51533
+
+Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.
+"""  # noqa: E501
+
+# Valid
+_ = """Lorem ipsum dolor sit amet.
+
+    https://github.com/PyCQA/pycodestyle/pull/258/files#diff-841c622497a8033d10152bfdfb15b20b92437ecdea21a260944ea86b77b51533
+
+Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.
+"""  # noqa
+
+# Invalid
+_ = """Lorem ipsum dolor sit amet.
+
+    https://github.com/PyCQA/pycodestyle/pull/258/files#diff-841c622497a8033d10152bfdfb15b20b92437ecdea21a260944ea86b77b51533
+
+Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.
+"""  # noqa: E501, F841
+
+# Invalid
+_ = """Lorem ipsum dolor sit amet.
+
+    https://github.com/PyCQA/pycodestyle/pull/258/files#diff-841c622497a8033d10152bfdfb15b20b92437ecdea21a260944ea86b77b51533
+
+Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor.
+"""  # noqa: E501
+
+# Invalid
+_ = """Lorem ipsum dolor sit amet.
+
+    https://github.com/PyCQA/pycodestyle/pull/258/files#diff-841c622497a8033d10152bfdfb15b20b92437ecdea21a260944ea86b77b51533
+
+Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor.
+"""  # noqa

resources/test/fixtures/__init__.py

@@ -0,0 +1,3 @@
+print(__path__)
+
+__all__ = ["a", "b", "c"]

resources/test/fixtures/directory/also_excluded.py

@@ -0,0 +1,9 @@
+a = "abc"
+b = f"ghi{'jkl'}"
+
+c = f"def"
+d = f"def" + "ghi"
+e = (
+    f"def" +
+    "ghi"
+)

resources/test/fixtures/pyproject.toml

@@ -1,47 +1,7 @@
 [tool.ruff]
 line-length = 88
-extend-exclude = ["excluded.py", "migrations"]
-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",
+extend-exclude = [
+    "excluded.py",
+    "migrations",
+    "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,
@@ -53,5 +61,11 @@ pub enum BindingKind {
 pub struct Binding {
     pub kind: BindingKind,
     pub location: Location,
-    pub used: Option<usize>,
+    /// Tuple of (scope index, location) indicating the scope and location at which the binding was
+    /// last used.
+    pub used: Option<(usize, Location)>,
+}
+
+pub trait CheckLocator {
+    fn locate_check(&self, default: Location) -> Location;
 }

src/cache.rs

@@ -1,11 +1,14 @@
 use std::collections::hash_map::DefaultHasher;
-use std::fs::Metadata;
+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 path_absolutize::Absolutize;
 use serde::{Deserialize, Serialize};
 
 use crate::autofix::fixer;
@@ -77,12 +80,22 @@ fn cache_key(path: &Path, settings: &Settings, autofix: &fixer::Mode) -> String
     autofix.hash(&mut hasher);
     format!(
         "{}@{}@{}",
-        path.canonicalize().unwrap().to_string_lossy(),
+        path.absolutize().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,

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;
@@ -26,7 +26,7 @@ struct Checker<'a> {
     locator: SourceCodeLocator<'a>,
     settings: &'a Settings,
     autofix: &'a fixer::Mode,
-    path: &'a str,
+    path: &'a Path,
     // Computed checks.
     checks: Vec<Check>,
     // Retain all scopes and parent nodes, along with a stack of indexes to track which are active
@@ -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,
@@ -55,7 +55,7 @@ impl<'a> Checker<'a> {
     pub fn new(
         settings: &'a Settings,
         autofix: &'a fixer::Mode,
-        path: &'a str,
+        path: &'a Path,
         content: &'a str,
     ) -> Checker<'a> {
         Checker {
@@ -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 =
@@ -184,7 +183,7 @@ where
                                 name.to_string(),
                                 Binding {
                                     kind: BindingKind::Assignment,
-                                    used: Some(global_scope_id),
+                                    used: Some((global_scope_id, stmt.location)),
                                     location: stmt.location,
                                 },
                             );
@@ -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),
                     ));
                 }
 
@@ -416,13 +432,14 @@ where
                             name,
                             Binding {
                                 kind: BindingKind::FutureImportation,
-                                used: Some(
+                                used: Some((
                                     self.scopes[*(self
                                         .scope_stack
                                         .last()
                                         .expect("No current scope found."))]
                                     .id,
-                                ),
+                                    stmt.location,
+                                )),
                                 location: stmt.location,
                             },
                         );
@@ -436,18 +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,
@@ -455,27 +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 {
@@ -503,14 +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);
                     }
                 }
@@ -524,7 +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);
                     }
                 }
@@ -532,9 +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);
                         }
                     }
@@ -589,7 +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,
@@ -615,9 +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);
                     }
@@ -627,9 +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);
                         }
                     }
@@ -645,6 +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);
@@ -654,6 +703,7 @@ where
                         keys,
                         check_repeated_literals,
                         check_repeated_variables,
+                        self,
                     ));
                 }
             }
@@ -666,12 +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
@@ -682,10 +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,
@@ -718,6 +770,7 @@ where
                         operand,
                         check_not_in,
                         check_not_is,
+                        self,
                     ));
                 }
             }
@@ -735,6 +788,7 @@ where
                         comparators,
                         check_none_comparisons,
                         check_true_false_comparisons,
+                        self,
                     ));
                 }
 
@@ -743,7 +797,7 @@ where
                         left,
                         ops,
                         comparators,
-                        expr.location,
+                        self.locate_check(expr.location),
                     ));
                 }
 
@@ -751,7 +805,7 @@ where
                     self.checks.extend(checks::check_type_comparison(
                         ops,
                         comparators,
-                        expr.location,
+                        self.locate_check(expr.location),
                     ));
                 }
             }
@@ -916,9 +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);
                             }
                         }
@@ -1018,14 +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());
@@ -1082,12 +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);
     }
 
@@ -1098,6 +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) {
@@ -1108,18 +1184,44 @@ impl<'a> Checker<'a> {
                     }
                 }
                 if let Some(binding) = scope.values.get_mut(id) {
-                    binding.used = Some(scope_id);
+                    binding.used = Some((scope_id, expr.location));
                     return;
                 }
 
                 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) {
+                // Allow __path__.
+                if self.path.ends_with("__init__.py") && id == "__path__" {
+                    return;
+                }
                 self.checks.push(Check::new(
                     CheckKind::UndefinedName(id.clone()),
-                    expr.location,
+                    self.locate_check(expr.location),
                 ))
             }
         }
@@ -1131,22 +1233,19 @@ 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) {
-                        let used = scope
-                            .values
-                            .get(id)
-                            .map(|binding| binding.used)
-                            .unwrap_or_default();
-                        if let Some(scope_id) = used {
-                            if scope_id == current.id {
-                                self.checks.push(Check::new(
-                                    CheckKind::UndefinedLocal(id.clone()),
-                                    expr.location,
-                                ));
+                    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()),
+                                        self.locate_check(location),
+                                    ));
+                                }
                             }
                         }
                     }
@@ -1169,8 +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 {
@@ -1226,7 +1336,7 @@ impl<'a> Checker<'a> {
             {
                 self.checks.push(Check::new(
                     CheckKind::UndefinedName(id.clone()),
-                    expr.location,
+                    self.locate_check(expr.location),
                 ))
             }
         }
@@ -1240,18 +1350,18 @@ impl<'a> Checker<'a> {
         }
     }
 
-    fn check_deferred_string_annotations<'b>(&mut self, path: &str, allocator: &'b mut Vec<Expr>)
+    fn check_deferred_string_annotations<'b>(&mut self, allocator: &'b mut Vec<Expr>)
     where
         'b: 'a,
     {
         while let Some((location, expression)) = self.deferred_string_annotations.pop() {
-            if let Ok(mut expr) = parser::parse_expression(expression, path) {
+            if let Ok(mut expr) = parser::parse_expression(expression, "<filename>") {
                 relocate_expr(&mut expr, location);
                 allocator.push(expr);
             } else if self.settings.select.contains(&CheckCode::F722) {
                 self.checks.push(Check::new(
                     CheckKind::ForwardAnnotationSyntaxError(expression.to_string()),
-                    location,
+                    self.locate_check(location),
                 ));
             }
         }
@@ -1264,7 +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, .. }
@@ -1288,7 +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);
@@ -1303,17 +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;
         }
@@ -1328,15 +1439,39 @@ impl<'a> Checker<'a> {
             });
 
             if self.settings.select.contains(&CheckCode::F822)
-                && !Path::new(self.path).ends_with("__init__.py")
+                && !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),
                                 ));
                             }
                         }
@@ -1357,7 +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),
                                 ));
                             }
                             _ => {}
@@ -1374,7 +1509,7 @@ pub fn check_ast(
     content: &str,
     settings: &Settings,
     autofix: &fixer::Mode,
-    path: &str,
+    path: &Path,
 ) -> Vec<Check> {
     let mut checker = Checker::new(settings, autofix, path, content);
     checker.push_scope(Scope::new(ScopeKind::Module));
@@ -1391,7 +1526,7 @@ pub fn check_ast(
     checker.check_deferred_assignments();
     checker.check_deferred_annotations();
     let mut allocator = vec![];
-    checker.check_deferred_string_annotations(path, &mut allocator);
+    checker.check_deferred_string_annotations(&mut allocator);
 
     // Reset the scope to module-level, and check all consumed scopes.
     checker.scope_stack = vec![GLOBAL_SCOPE_INDEX];

src/check_lines.rs

@@ -1,6 +1,11 @@
+use std::collections::BTreeMap;
+
 use rustpython_parser::ast::Location;
 
-use crate::checks::{Check, CheckCode, CheckKind};
+use crate::autofix::fixer;
+use crate::checks::{Check, CheckCode, CheckKind, Fix};
+use crate::noqa;
+use crate::noqa::Directive;
 use crate::settings::Settings;
 
 /// Whether the given line is too long and should be reported.
@@ -19,37 +24,191 @@ fn should_enforce_line_length(line: &str, length: usize, limit: usize) -> bool {
     }
 }
 
-pub fn check_lines(checks: &mut Vec<Check>, contents: &str, settings: &Settings) {
+pub fn check_lines(
+    checks: &mut Vec<Check>,
+    contents: &str,
+    noqa_line_for: &[usize],
+    settings: &Settings,
+    autofix: &fixer::Mode,
+) {
     let enforce_line_too_long = settings.select.contains(&CheckCode::E501);
+    let enforce_noqa = settings.select.contains(&CheckCode::M001);
+
+    let mut noqa_directives: BTreeMap<usize, (Directive, Vec<&str>)> = BTreeMap::new();
 
     let mut line_checks = vec![];
     let mut ignored = vec![];
-    for (row, line) in contents.lines().enumerate() {
+
+    let lines: Vec<&str> = contents.lines().collect();
+    for (lineno, line) in lines.iter().enumerate() {
+        // Grab the noqa (logical) line number for the current (physical) line.
+        // If there are newlines at the end of the file, they won't be represented in
+        // `noqa_line_for`, so fallback to the current line.
+        let noqa_lineno = noqa_line_for
+            .get(lineno)
+            .map(|lineno| lineno - 1)
+            .unwrap_or(lineno);
+
+        if enforce_noqa {
+            noqa_directives
+                .entry(noqa_lineno)
+                .or_insert_with(|| (noqa::extract_noqa_directive(lines[noqa_lineno]), vec![]));
+        }
+
         // Remove any ignored checks.
         // TODO(charlie): Only validate checks for the current line.
         for (index, check) in checks.iter().enumerate() {
-            if check.location.row() == row + 1 && check.is_inline_ignored(line) {
-                ignored.push(index);
+            if check.location.row() == lineno + 1 {
+                let noqa = noqa_directives
+                    .entry(noqa_lineno)
+                    .or_insert_with(|| (noqa::extract_noqa_directive(lines[noqa_lineno]), vec![]));
+
+                match noqa {
+                    (Directive::All(_), matches) => {
+                        matches.push(check.kind.code().as_str());
+                        ignored.push(index)
+                    }
+                    (Directive::Codes(_, codes), matches) => {
+                        if codes.contains(&check.kind.code().as_str()) {
+                            matches.push(check.kind.code().as_str());
+                            ignored.push(index);
+                        }
+                    }
+                    (Directive::None, _) => {}
+                }
             }
         }
 
         // 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 noqa = noqa_directives
+                    .entry(noqa_lineno)
+                    .or_insert_with(|| (noqa::extract_noqa_directive(lines[noqa_lineno]), vec![]));
+
                 let check = Check::new(
                     CheckKind::LineTooLong(line_length, settings.line_length),
-                    Location::new(row + 1, settings.line_length + 1),
+                    Location::new(lineno + 1, settings.line_length + 1),
                 );
-                if !check.is_inline_ignored(line) {
-                    line_checks.push(check);
+
+                match noqa {
+                    (Directive::All(_), matches) => {
+                        matches.push(check.kind.code().as_str());
+                    }
+                    (Directive::Codes(_, codes), matches) => {
+                        if codes.contains(&check.kind.code().as_str()) {
+                            matches.push(check.kind.code().as_str());
+                        } else {
+                            line_checks.push(check);
+                        }
+                    }
+                    (Directive::None, _) => line_checks.push(check),
                 }
             }
         }
     }
+
+    // Enforce that the noqa directive was actually used.
+    if enforce_noqa {
+        for (row, (directive, matches)) in noqa_directives {
+            match directive {
+                Directive::All(column) => {
+                    if matches.is_empty() {
+                        let mut check = Check::new(
+                            CheckKind::UnusedNOQA(None),
+                            Location::new(row + 1, column + 1),
+                        );
+                        if matches!(autofix, fixer::Mode::Generate | fixer::Mode::Apply) {
+                            check.amend(Fix {
+                                content: "".to_string(),
+                                start: Location::new(row + 1, column + 1),
+                                end: Location::new(row + 1, lines[row].chars().count() + 1),
+                                applied: false,
+                            });
+                        }
+                        line_checks.push(check);
+                    }
+                }
+                Directive::Codes(column, codes) => {
+                    let mut invalid_codes = vec![];
+                    let mut valid_codes = vec![];
+                    for code in codes {
+                        if !matches.contains(&code) {
+                            invalid_codes.push(code);
+                        } else {
+                            valid_codes.push(code);
+                        }
+                    }
+
+                    if !invalid_codes.is_empty() {
+                        let mut check = Check::new(
+                            CheckKind::UnusedNOQA(Some(invalid_codes.join(", "))),
+                            Location::new(row + 1, column + 1),
+                        );
+                        if matches!(autofix, fixer::Mode::Generate | fixer::Mode::Apply) {
+                            if valid_codes.is_empty() {
+                                check.amend(Fix {
+                                    content: "".to_string(),
+                                    start: Location::new(row + 1, column + 1),
+                                    end: Location::new(row + 1, lines[row].chars().count() + 1),
+                                    applied: false,
+                                });
+                            } else {
+                                check.amend(Fix {
+                                    content: format!("  # noqa: {}", valid_codes.join(", ")),
+                                    start: Location::new(row + 1, column + 1),
+                                    end: Location::new(row + 1, lines[row].chars().count() + 1),
+                                    applied: false,
+                                });
+                            }
+                        }
+                        line_checks.push(check);
+                    }
+                }
+                Directive::None => {}
+            }
+        }
+    }
+
     ignored.sort();
     for index in ignored.iter().rev() {
         checks.swap_remove(*index);
     }
     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 noqa_line_for: Vec<usize> = vec![1];
+        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,
+                &noqa_line_for,
+                &settings,
+                &fixer::Mode::Generate,
+            );
+            return checks;
+        };
+        assert!(!check_with_max_line_length(6).is_empty());
+        assert!(check_with_max_line_length(7).is_empty());
+    }
+}

src/checks.rs

@@ -1,12 +1,103 @@
 use std::str::FromStr;
 
 use anyhow::Result;
-use once_cell::sync::Lazy;
-use regex::Regex;
 use rustpython_parser::ast::Location;
 use serde::{Deserialize, Serialize};
 
-#[derive(Debug, PartialEq, Eq, Serialize, Deserialize, Hash, PartialOrd, Ord)]
+pub const DEFAULT_CHECK_CODES: [CheckCode; 42] = [
+    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,
+];
+
+pub const ALL_CHECK_CODES: [CheckCode; 45] = [
+    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::M001,
+    CheckCode::R001,
+    CheckCode::R002,
+];
+
+#[derive(Debug, PartialEq, Eq, Clone, Serialize, Deserialize, Hash, PartialOrd, Ord)]
 pub enum CheckCode {
     E402,
     E501,
@@ -23,8 +114,10 @@ pub enum CheckCode {
     E902,
     E999,
     F401,
+    F402,
     F403,
     F404,
+    F405,
     F406,
     F407,
     F541,
@@ -50,6 +143,7 @@ pub enum CheckCode {
     F901,
     R001,
     R002,
+    M001,
 }
 
 impl FromStr for CheckCode {
@@ -72,8 +166,10 @@ 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),
@@ -99,6 +195,7 @@ impl FromStr for CheckCode {
             "F901" => Ok(CheckCode::F901),
             "R001" => Ok(CheckCode::R001),
             "R002" => Ok(CheckCode::R002),
+            "M001" => Ok(CheckCode::M001),
             _ => Err(anyhow::anyhow!("Unknown check code: {s}")),
         }
     }
@@ -122,8 +219,10 @@ 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",
@@ -149,17 +248,69 @@ impl CheckCode {
             CheckCode::F901 => "F901",
             CheckCode::R001 => "R001",
             CheckCode::R002 => "R002",
+            CheckCode::M001 => "M001",
         }
     }
 
     /// The source for the check (either the AST, the filesystem, or the physical lines).
     pub fn lint_source(&self) -> &'static LintSource {
         match self {
-            CheckCode::E501 => &LintSource::Lines,
+            CheckCode::E501 | CheckCode::M001 => &LintSource::Lines,
             CheckCode::E902 | CheckCode::E999 => &LintSource::FileSystem,
             _ => &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::M001 => CheckKind::UnusedNOQA(None),
+            CheckCode::R001 => CheckKind::UselessObjectInheritance("...".to_string()),
+            CheckCode::R002 => CheckKind::NoAssertEquals,
+        }
+    }
 }
 
 #[allow(clippy::upper_case_acronyms)]
@@ -177,6 +328,7 @@ pub enum RejectedCmpop {
 
 #[derive(Debug, PartialEq, Eq, Serialize, Deserialize)]
 pub enum CheckKind {
+    UnusedNOQA(Option<String>),
     AmbiguousClassName(String),
     AmbiguousFunctionName(String),
     AmbiguousVariableName(String),
@@ -192,8 +344,10 @@ 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 +394,10 @@ 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",
@@ -269,6 +425,7 @@ impl CheckKind {
             CheckKind::UnusedVariable(_) => "UnusedVariable",
             CheckKind::UselessObjectInheritance(_) => "UselessObjectInheritance",
             CheckKind::YieldOutsideFunction => "YieldOutsideFunction",
+            CheckKind::UnusedNOQA(_) => "UnusedNOQA",
         }
     }
 
@@ -290,8 +447,10 @@ 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::ImportStarUsage(_, _) => &CheckCode::F405,
+            CheckKind::ImportStarUsed(_) => &CheckCode::F403,
             CheckKind::InvalidPrintSyntax => &CheckCode::F633,
             CheckKind::IsLiteral => &CheckCode::F632,
             CheckKind::LateFutureImport => &CheckCode::F404,
@@ -314,6 +473,7 @@ impl CheckKind {
             CheckKind::UndefinedLocal(_) => &CheckCode::F823,
             CheckKind::UndefinedName(_) => &CheckCode::F821,
             CheckKind::UnusedImport(_) => &CheckCode::F401,
+            CheckKind::UnusedNOQA(_) => &CheckCode::M001,
             CheckKind::UnusedVariable(_) => &CheckCode::F841,
             CheckKind::UselessObjectInheritance(_) => &CheckCode::R001,
             CheckKind::YieldOutsideFunction => &CheckCode::F704,
@@ -356,17 +516,21 @@ 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()
@@ -443,6 +607,10 @@ impl CheckKind {
             CheckKind::YieldOutsideFunction => {
                 "a `yield` or `yield from` statement outside of a function/method".to_string()
             }
+            CheckKind::UnusedNOQA(code) => match code {
+                None => "Unused `noqa` directive".to_string(),
+                Some(code) => format!("Unused `noqa` directive for: {code}"),
+            },
         }
     }
 
@@ -450,7 +618,9 @@ impl CheckKind {
     pub fn fixable(&self) -> bool {
         matches!(
             self,
-            CheckKind::NoAssertEquals | CheckKind::UselessObjectInheritance(_)
+            CheckKind::NoAssertEquals
+                | CheckKind::UselessObjectInheritance(_)
+                | CheckKind::UnusedNOQA(_)
         )
     }
 }
@@ -470,11 +640,6 @@ pub struct Check {
     pub fix: Option<Fix>,
 }
 
-static NO_QA_REGEX: Lazy<Regex> = Lazy::new(|| {
-    Regex::new(r"(?i)# noqa(?::\s?(?P<codes>([A-Z]+[0-9]+(?:[,\s]+)?)+))?").expect("Invalid regex")
-});
-static SPLIT_COMMA_REGEX: Lazy<Regex> = Lazy::new(|| Regex::new(r"[,\s]").expect("Invalid regex"));
-
 impl Check {
     pub fn new(kind: CheckKind, location: Location) -> Self {
         Self {
@@ -487,25 +652,4 @@ impl Check {
     pub fn amend(&mut self, fix: Fix) {
         self.fix = Some(fix);
     }
-
-    pub fn is_inline_ignored(&self, line: &str) -> bool {
-        match NO_QA_REGEX.captures(line) {
-            Some(caps) => match caps.name("codes") {
-                Some(codes) => {
-                    for code in SPLIT_COMMA_REGEX
-                        .split(codes.as_str())
-                        .map(|code| code.trim())
-                        .filter(|code| !code.is_empty())
-                    {
-                        if code == self.kind.code().as_str() {
-                            return true;
-                        }
-                    }
-                    false
-                }
-                None => true,
-            },
-            None => false,
-        }
-    }
 }

src/fs.rs

@@ -1,27 +1,53 @@
+use std::borrow::Cow;
 use std::fs::File;
 use std::io::{BufReader, Read};
+use std::ops::Deref;
 use std::path::{Path, PathBuf};
 
-use anyhow::Result;
-use glob::Pattern;
+use anyhow::{anyhow, Result};
 use log::debug;
+use path_absolutize::path_dedot;
+use path_absolutize::Absolutize;
 use walkdir::{DirEntry, WalkDir};
 
-fn is_excluded(path: &Path, exclude: &[Pattern]) -> bool {
-    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) {
+use crate::settings::FilePattern;
+
+/// Extract the absolute path and basename (as strings) from a Path.
+fn extract_path_names(path: &Path) -> Result<(&str, &str)> {
+    let file_path = path
+        .to_str()
+        .ok_or_else(|| anyhow!("Unable to parse filename: {:?}", path))?;
+    let file_basename = path
+        .file_name()
+        .ok_or_else(|| anyhow!("Unable to parse filename: {:?}", path))?
+        .to_str()
+        .ok_or_else(|| anyhow!("Unable to parse filename: {:?}", path))?;
+    Ok((file_path, file_basename))
+}
+
+fn is_excluded(file_path: &str, file_basename: &str, exclude: &[FilePattern]) -> bool {
+    for pattern in exclude {
+        match &pattern {
+            FilePattern::Simple(basename) => {
+                if *basename == file_basename {
+                    return true;
+                }
+            }
+            FilePattern::Complex(absolute, basename) => {
+                if absolute.matches(file_path) {
+                    return true;
+                }
+                if basename
+                    .as_ref()
+                    .map(|pattern| pattern.matches(file_basename))
+                    .unwrap_or_default()
+                {
                     return true;
                 }
             }
-            false
-        } else {
-            false
         }
-    } else {
-        false
     }
+    false
 }
 
 fn is_included(path: &Path) -> bool {
@@ -30,36 +56,87 @@ fn is_included(path: &Path) -> bool {
 }
 
 pub fn iter_python_files<'a>(
-    path: &'a PathBuf,
-    exclude: &'a [Pattern],
-    extend_exclude: &'a [Pattern],
-) -> impl Iterator<Item = DirEntry> + 'a {
-    WalkDir::new(path)
+    path: &'a Path,
+    exclude: &'a [FilePattern],
+    extend_exclude: &'a [FilePattern],
+) -> impl Iterator<Item = Result<DirEntry, walkdir::Error>> + 'a {
+    // Run some checks over the provided patterns, to enable optimizations below.
+    let has_exclude = !exclude.is_empty();
+    let has_extend_exclude = !extend_exclude.is_empty();
+    let exclude_simple = exclude
+        .iter()
+        .all(|pattern| matches!(pattern, FilePattern::Simple(_)));
+    let extend_exclude_simple = extend_exclude
+        .iter()
+        .all(|pattern| matches!(pattern, FilePattern::Simple(_)));
+
+    WalkDir::new(normalize_path(path))
         .follow_links(true)
         .into_iter()
-        .filter_entry(|entry| {
-            if exclude.is_empty() && extend_exclude.is_empty() {
+        .filter_entry(move |entry| {
+            if !has_exclude && !has_extend_exclude {
                 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
+            match extract_path_names(path) {
+                Ok((file_path, file_basename)) => {
+                    let file_type = entry.file_type();
+
+                    if has_exclude
+                        && (!exclude_simple || file_type.is_dir())
+                        && is_excluded(file_path, file_basename, exclude)
+                    {
+                        debug!("Ignored path via `exclude`: {:?}", path);
+                        false
+                    } else if has_extend_exclude
+                        && (!extend_exclude_simple || file_type.is_dir())
+                        && is_excluded(file_path, file_basename, extend_exclude)
+                    {
+                        debug!("Ignored path via `extend-exclude`: {:?}", path);
+                        false
+                    } else {
+                        true
+                    }
+                }
+                Err(_) => {
+                    debug!("Ignored path due to error in parsing: {:?}", path);
+                    true
+                }
             }
         })
-        .filter_map(|entry| entry.ok())
         .filter(|entry| {
-            let path = entry.path();
-            is_included(path)
+            entry.as_ref().map_or(true, |entry| {
+                (entry.depth() == 0 && !entry.file_type().is_dir()) || is_included(entry.path())
+            })
         })
 }
 
+/// Convert any path to an absolute path (based on the current working directory).
+pub fn normalize_path(path: &Path) -> PathBuf {
+    if let Ok(path) = path.absolutize() {
+        return path.to_path_buf();
+    }
+    path.to_path_buf()
+}
+
+/// Convert any path to an absolute path (based on the specified project root).
+pub fn normalize_path_to(path: &Path, project_root: &Path) -> PathBuf {
+    if let Ok(path) = path.absolutize_from(project_root) {
+        return path.to_path_buf();
+    }
+    path.to_path_buf()
+}
+
+/// Convert an absolute path to be relative to the current working directory.
+pub fn relativize_path(path: &Path) -> Cow<str> {
+    if let Ok(path) = path.strip_prefix(path_dedot::CWD.deref()) {
+        return path.to_string_lossy();
+    }
+    path.to_string_lossy()
+}
+
+/// Read a file's contents from disk.
 pub fn read_file(path: &Path) -> Result<String> {
     let file = File::open(path)?;
     let mut buf_reader = BufReader::new(file);
@@ -72,41 +149,95 @@ pub fn read_file(path: &Path) -> Result<String> {
 mod tests {
     use std::path::Path;
 
-    use glob::Pattern;
+    use anyhow::Result;
+    use path_absolutize::Absolutize;
 
-    use crate::fs::{is_excluded, is_included};
+    use crate::fs::{extract_path_names, is_excluded, is_included};
+    use crate::settings::FilePattern;
 
     #[test]
     fn inclusions() {
-        let path = Path::new("foo/bar/baz.py");
-        assert!(is_included(path));
+        let path = Path::new("foo/bar/baz.py").absolutize().unwrap();
+        assert!(is_included(&path));
 
-        let path = Path::new("foo/bar/baz.pyi");
-        assert!(is_included(path));
+        let path = Path::new("foo/bar/baz.pyi").absolutize().unwrap();
+        assert!(is_included(&path));
 
-        let path = Path::new("foo/bar/baz.js");
-        assert!(!is_included(path));
+        let path = Path::new("foo/bar/baz.js").absolutize().unwrap();
+        assert!(!is_included(&path));
 
-        let path = Path::new("foo/bar/baz");
-        assert!(!is_included(path));
+        let path = Path::new("foo/bar/baz").absolutize().unwrap();
+        assert!(!is_included(&path));
     }
 
     #[test]
-    fn exclusions() {
-        let path = Path::new("foo");
-        let exclude = vec![Pattern::new("foo").unwrap()];
-        assert!(is_excluded(path, &exclude));
+    fn exclusions() -> Result<()> {
+        let project_root = Path::new("/tmp/");
 
-        let path = Path::new("foo/bar");
-        let exclude = vec![Pattern::new("bar").unwrap()];
-        assert!(is_excluded(path, &exclude));
+        let path = Path::new("foo").absolutize_from(project_root).unwrap();
+        let exclude = vec![FilePattern::from_user(
+            "foo",
+            &Some(project_root.to_path_buf()),
+        )];
+        let (file_path, file_basename) = extract_path_names(&path)?;
+        assert!(is_excluded(file_path, file_basename, &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").absolutize_from(project_root).unwrap();
+        let exclude = vec![FilePattern::from_user(
+            "bar",
+            &Some(project_root.to_path_buf()),
+        )];
+        let (file_path, file_basename) = extract_path_names(&path)?;
+        assert!(is_excluded(file_path, file_basename, &exclude));
 
-        let path = Path::new("foo/bar/baz.py");
-        let exclude = vec![Pattern::new("baz").unwrap()];
-        assert!(!is_excluded(path, &exclude));
+        let path = Path::new("foo/bar/baz.py")
+            .absolutize_from(project_root)
+            .unwrap();
+        let exclude = vec![FilePattern::from_user(
+            "baz.py",
+            &Some(project_root.to_path_buf()),
+        )];
+        let (file_path, file_basename) = extract_path_names(&path)?;
+        assert!(is_excluded(file_path, file_basename, &exclude));
+
+        let path = Path::new("foo/bar").absolutize_from(project_root).unwrap();
+        let exclude = vec![FilePattern::from_user(
+            "foo/bar",
+            &Some(project_root.to_path_buf()),
+        )];
+        let (file_path, file_basename) = extract_path_names(&path)?;
+        assert!(is_excluded(file_path, file_basename, &exclude));
+
+        let path = Path::new("foo/bar/baz.py")
+            .absolutize_from(project_root)
+            .unwrap();
+        let exclude = vec![FilePattern::from_user(
+            "foo/bar/baz.py",
+            &Some(project_root.to_path_buf()),
+        )];
+        let (file_path, file_basename) = extract_path_names(&path)?;
+        assert!(is_excluded(file_path, file_basename, &exclude));
+
+        let path = Path::new("foo/bar/baz.py")
+            .absolutize_from(project_root)
+            .unwrap();
+        let exclude = vec![FilePattern::from_user(
+            "foo/bar/*.py",
+            &Some(project_root.to_path_buf()),
+        )];
+        let (file_path, file_basename) = extract_path_names(&path)?;
+        assert!(is_excluded(file_path, file_basename, &exclude));
+
+        let path = Path::new("foo/bar/baz.py")
+            .absolutize_from(project_root)
+            .unwrap();
+        let exclude = vec![FilePattern::from_user(
+            "baz",
+            &Some(project_root.to_path_buf()),
+        )];
+        let (file_path, file_basename) = extract_path_names(&path)?;
+        assert!(!is_excluded(file_path, file_basename, &exclude));
+
+        Ok(())
     }
 }

src/lib.rs

@@ -2,7 +2,7 @@ extern crate core;
 
 mod ast;
 mod autofix;
-mod cache;
+pub mod cache;
 pub mod check_ast;
 mod check_lines;
 pub mod checks;
@@ -10,6 +10,8 @@ pub mod fs;
 pub mod linter;
 pub mod logging;
 pub mod message;
-mod pyproject;
+mod noqa;
+pub mod printer;
+pub mod pyproject;
 mod python;
 pub mod settings;

src/linter.rs

@@ -2,39 +2,57 @@ use std::path::Path;
 
 use anyhow::Result;
 use log::debug;
-use rustpython_parser::parser;
+use rustpython_parser::lexer::LexResult;
+use rustpython_parser::{lexer, 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::checks::{Check, CheckCode, CheckKind, LintSource};
 use crate::message::Message;
+use crate::noqa::add_noqa;
 use crate::settings::Settings;
-use crate::{cache, fs};
-
-fn check_path(path: &Path, settings: &Settings, autofix: &fixer::Mode) -> Result<Vec<Check>> {
-    // Read the file from disk.
-    let contents = fs::read_file(path)?;
+use crate::{cache, fs, noqa};
 
+fn check_path(
+    path: &Path,
+    contents: &str,
+    tokens: Vec<LexResult>,
+    settings: &Settings,
+    autofix: &fixer::Mode,
+) -> Vec<Check> {
     // Aggregate all checks.
     let mut checks: Vec<Check> = vec![];
 
+    // Determine the noqa line for every line in the source.
+    let noqa_line_for = noqa::extract_noqa_line_for(&tokens);
+
     // Run the AST-based checks.
     if settings
         .select
         .iter()
         .any(|check_code| matches!(check_code.lint_source(), LintSource::AST))
     {
-        let path = path.to_string_lossy();
-        let python_ast = parser::parse_program(&contents, &path)?;
-        checks.extend(check_ast(&python_ast, &contents, settings, autofix, &path));
+        match parser::parse_program_tokens(tokens, "<filename>") {
+            Ok(python_ast) => {
+                checks.extend(check_ast(&python_ast, contents, settings, autofix, path))
+            }
+            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);
+    check_lines(&mut checks, contents, &noqa_line_for, settings, autofix);
 
-    Ok(checks)
+    checks
 }
 
 pub fn lint_path(
@@ -54,8 +72,11 @@ pub fn lint_path(
     // Read the file from disk.
     let contents = fs::read_file(path)?;
 
+    // Tokenize once.
+    let tokens: Vec<LexResult> = lexer::make_tokenizer(&contents).collect();
+
     // Generate checks.
-    let mut checks = check_path(path, settings, autofix)?;
+    let mut checks = check_path(path, &contents, tokens, settings, autofix);
 
     // Apply autofix.
     if matches!(autofix, fixer::Mode::Apply) {
@@ -77,28 +98,53 @@ pub fn lint_path(
     Ok(messages)
 }
 
+pub fn add_noqa_to_path(path: &Path, settings: &Settings) -> Result<usize> {
+    // Read the file from disk.
+    let contents = fs::read_file(path)?;
+
+    // Tokenize once.
+    let tokens: Vec<LexResult> = lexer::make_tokenizer(&contents).collect();
+
+    // Determine the noqa line for every line in the source.
+    let noqa_line_for = noqa::extract_noqa_line_for(&tokens);
+
+    // Generate checks.
+    let checks = check_path(path, &contents, tokens, settings, &fixer::Mode::None);
+
+    add_noqa(&checks, &contents, &noqa_line_for, path)
+}
+
 #[cfg(test)]
 mod tests {
-    use std::collections::BTreeSet;
     use std::path::Path;
 
     use anyhow::Result;
+    use rustpython_parser::lexer;
+    use rustpython_parser::lexer::LexResult;
 
     use crate::autofix::fixer;
-    use crate::checks::CheckCode;
-    use crate::linter::check_path;
+    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)?;
+        let tokens: Vec<LexResult> = lexer::make_tokenizer(&contents).collect();
+        Ok(linter::check_path(
+            path, &contents, tokens, 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]),
-            },
+            &settings::Settings::for_rule(CheckCode::E402),
             &fixer::Mode::Generate,
         )?;
         checks.sort_by_key(|check| check.location);
@@ -110,12 +156,7 @@ mod tests {
     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]),
-            },
+            &settings::Settings::for_rule(CheckCode::E501),
             &fixer::Mode::Generate,
         )?;
         checks.sort_by_key(|check| check.location);
@@ -127,12 +168,7 @@ mod tests {
     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]),
-            },
+            &settings::Settings::for_rule(CheckCode::E711),
             &fixer::Mode::Generate,
         )?;
         checks.sort_by_key(|check| check.location);
@@ -144,12 +180,7 @@ mod tests {
     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]),
-            },
+            &settings::Settings::for_rule(CheckCode::E712),
             &fixer::Mode::Generate,
         )?;
         checks.sort_by_key(|check| check.location);
@@ -161,12 +192,7 @@ mod tests {
     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]),
-            },
+            &settings::Settings::for_rule(CheckCode::E713),
             &fixer::Mode::Generate,
         )?;
         checks.sort_by_key(|check| check.location);
@@ -178,12 +204,7 @@ mod tests {
     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]),
-            },
+            &settings::Settings::for_rule(CheckCode::E721),
             &fixer::Mode::Generate,
         )?;
         checks.sort_by_key(|check| check.location);
@@ -195,12 +216,7 @@ mod tests {
     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]),
-            },
+            &settings::Settings::for_rule(CheckCode::E722),
             &fixer::Mode::Generate,
         )?;
         checks.sort_by_key(|check| check.location);
@@ -212,12 +228,7 @@ mod tests {
     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]),
-            },
+            &settings::Settings::for_rule(CheckCode::E714),
             &fixer::Mode::Generate,
         )?;
         checks.sort_by_key(|check| check.location);
@@ -229,12 +240,7 @@ mod tests {
     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]),
-            },
+            &settings::Settings::for_rule(CheckCode::E731),
             &fixer::Mode::Generate,
         )?;
         checks.sort_by_key(|check| check.location);
@@ -246,12 +252,7 @@ mod tests {
     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]),
-            },
+            &settings::Settings::for_rule(CheckCode::E741),
             &fixer::Mode::Generate,
         )?;
         checks.sort_by_key(|check| check.location);
@@ -263,12 +264,7 @@ mod tests {
     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]),
-            },
+            &settings::Settings::for_rule(CheckCode::E742),
             &fixer::Mode::Generate,
         )?;
         checks.sort_by_key(|check| check.location);
@@ -280,12 +276,7 @@ mod tests {
     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]),
-            },
+            &settings::Settings::for_rule(CheckCode::E743),
             &fixer::Mode::Generate,
         )?;
         checks.sort_by_key(|check| check.location);
@@ -297,12 +288,19 @@ mod tests {
     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]),
-            },
+            &settings::Settings::for_rule(CheckCode::F401),
+            &fixer::Mode::Generate,
+        )?;
+        checks.sort_by_key(|check| check.location);
+        insta::assert_yaml_snapshot!(checks);
+        Ok(())
+    }
+
+    #[test]
+    fn f402() -> Result<()> {
+        let mut checks = check_path(
+            Path::new("./resources/test/fixtures/F402.py"),
+            &settings::Settings::for_rule(CheckCode::F402),
             &fixer::Mode::Generate,
         )?;
         checks.sort_by_key(|check| check.location);
@@ -314,12 +312,7 @@ mod tests {
     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]),
-            },
+            &settings::Settings::for_rule(CheckCode::F403),
             &fixer::Mode::Generate,
         )?;
         checks.sort_by_key(|check| check.location);
@@ -331,12 +324,19 @@ mod tests {
     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]),
-            },
+            &settings::Settings::for_rule(CheckCode::F404),
+            &fixer::Mode::Generate,
+        )?;
+        checks.sort_by_key(|check| check.location);
+        insta::assert_yaml_snapshot!(checks);
+        Ok(())
+    }
+
+    #[test]
+    fn f405() -> Result<()> {
+        let mut checks = check_path(
+            Path::new("./resources/test/fixtures/F405.py"),
+            &settings::Settings::for_rule(CheckCode::F405),
             &fixer::Mode::Generate,
         )?;
         checks.sort_by_key(|check| check.location);
@@ -348,12 +348,7 @@ mod tests {
     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]),
-            },
+            &settings::Settings::for_rule(CheckCode::F406),
             &fixer::Mode::Generate,
         )?;
         checks.sort_by_key(|check| check.location);
@@ -365,12 +360,7 @@ mod tests {
     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]),
-            },
+            &settings::Settings::for_rule(CheckCode::F407),
             &fixer::Mode::Generate,
         )?;
         checks.sort_by_key(|check| check.location);
@@ -382,12 +372,7 @@ mod tests {
     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]),
-            },
+            &settings::Settings::for_rule(CheckCode::F541),
             &fixer::Mode::Generate,
         )?;
         checks.sort_by_key(|check| check.location);
@@ -399,12 +384,7 @@ mod tests {
     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]),
-            },
+            &settings::Settings::for_rule(CheckCode::F601),
             &fixer::Mode::Generate,
         )?;
         checks.sort_by_key(|check| check.location);
@@ -416,12 +396,7 @@ mod tests {
     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]),
-            },
+            &settings::Settings::for_rule(CheckCode::F602),
             &fixer::Mode::Generate,
         )?;
         checks.sort_by_key(|check| check.location);
@@ -433,12 +408,7 @@ mod tests {
     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]),
-            },
+            &settings::Settings::for_rule(CheckCode::F622),
             &fixer::Mode::Generate,
         )?;
         checks.sort_by_key(|check| check.location);
@@ -450,12 +420,7 @@ mod tests {
     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]),
-            },
+            &settings::Settings::for_rule(CheckCode::F631),
             &fixer::Mode::Generate,
         )?;
         checks.sort_by_key(|check| check.location);
@@ -467,12 +432,7 @@ mod tests {
     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]),
-            },
+            &settings::Settings::for_rule(CheckCode::F632),
             &fixer::Mode::Generate,
         )?;
         checks.sort_by_key(|check| check.location);
@@ -484,12 +444,7 @@ mod tests {
     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]),
-            },
+            &settings::Settings::for_rule(CheckCode::F633),
             &fixer::Mode::Generate,
         )?;
         checks.sort_by_key(|check| check.location);
@@ -501,12 +456,7 @@ mod tests {
     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]),
-            },
+            &settings::Settings::for_rule(CheckCode::F634),
             &fixer::Mode::Generate,
         )?;
         checks.sort_by_key(|check| check.location);
@@ -518,12 +468,7 @@ mod tests {
     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]),
-            },
+            &settings::Settings::for_rule(CheckCode::F701),
             &fixer::Mode::Generate,
         )?;
         checks.sort_by_key(|check| check.location);
@@ -535,12 +480,7 @@ mod tests {
     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]),
-            },
+            &settings::Settings::for_rule(CheckCode::F702),
             &fixer::Mode::Generate,
         )?;
         checks.sort_by_key(|check| check.location);
@@ -552,12 +492,7 @@ mod tests {
     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]),
-            },
+            &settings::Settings::for_rule(CheckCode::F704),
             &fixer::Mode::Generate,
         )?;
         checks.sort_by_key(|check| check.location);
@@ -569,12 +504,7 @@ mod tests {
     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]),
-            },
+            &settings::Settings::for_rule(CheckCode::F706),
             &fixer::Mode::Generate,
         )?;
         checks.sort_by_key(|check| check.location);
@@ -586,12 +516,7 @@ mod tests {
     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]),
-            },
+            &settings::Settings::for_rule(CheckCode::F707),
             &fixer::Mode::Generate,
         )?;
         checks.sort_by_key(|check| check.location);
@@ -603,12 +528,7 @@ mod tests {
     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]),
-            },
+            &settings::Settings::for_rule(CheckCode::F722),
             &fixer::Mode::Generate,
         )?;
         checks.sort_by_key(|check| check.location);
@@ -620,12 +540,7 @@ mod tests {
     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]),
-            },
+            &settings::Settings::for_rule(CheckCode::F821),
             &fixer::Mode::Generate,
         )?;
         checks.sort_by_key(|check| check.location);
@@ -637,12 +552,7 @@ mod tests {
     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]),
-            },
+            &settings::Settings::for_rule(CheckCode::F822),
             &fixer::Mode::Generate,
         )?;
         checks.sort_by_key(|check| check.location);
@@ -654,12 +564,7 @@ mod tests {
     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]),
-            },
+            &settings::Settings::for_rule(CheckCode::F823),
             &fixer::Mode::Generate,
         )?;
         checks.sort_by_key(|check| check.location);
@@ -671,12 +576,7 @@ mod tests {
     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]),
-            },
+            &settings::Settings::for_rule(CheckCode::F831),
             &fixer::Mode::Generate,
         )?;
         checks.sort_by_key(|check| check.location);
@@ -688,12 +588,7 @@ mod tests {
     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]),
-            },
+            &settings::Settings::for_rule(CheckCode::F841),
             &fixer::Mode::Generate,
         )?;
         checks.sort_by_key(|check| check.location);
@@ -705,12 +600,19 @@ mod tests {
     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]),
-            },
+            &settings::Settings::for_rule(CheckCode::F901),
+            &fixer::Mode::Generate,
+        )?;
+        checks.sort_by_key(|check| check.location);
+        insta::assert_yaml_snapshot!(checks);
+        Ok(())
+    }
+
+    #[test]
+    fn m001() -> Result<()> {
+        let mut checks = check_path(
+            Path::new("./resources/test/fixtures/M001.py"),
+            &settings::Settings::for_rules(vec![CheckCode::M001, CheckCode::E501, CheckCode::F841]),
             &fixer::Mode::Generate,
         )?;
         checks.sort_by_key(|check| check.location);
@@ -722,12 +624,7 @@ mod tests {
     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]),
-            },
+            &settings::Settings::for_rule(CheckCode::R001),
             &fixer::Mode::Generate,
         )?;
         checks.sort_by_key(|check| check.location);
@@ -739,12 +636,19 @@ mod tests {
     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]),
-            },
+            &settings::Settings::for_rule(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::for_rules(vec![CheckCode::F821, CheckCode::F822]),
             &fixer::Mode::Generate,
         )?;
         checks.sort_by_key(|check| check.location);
@@ -756,12 +660,7 @@ mod tests {
     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]),
-            },
+            &settings::Settings::for_rules(vec![CheckCode::F401, CheckCode::F821]),
             &fixer::Mode::Generate,
         )?;
         checks.sort_by_key(|check| check.location);

src/main.rs

@@ -1,4 +1,7 @@
-use std::path::PathBuf;
+extern crate core;
+
+use std::io;
+use std::path::{Path, PathBuf};
 use std::process::ExitCode;
 use std::sync::mpsc::channel;
 use std::time::Instant;
@@ -6,20 +9,23 @@ 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::settings::Settings;
+use ::ruff::printer::{Printer, SerializationFormat};
+use ::ruff::pyproject;
+use ::ruff::settings::{FilePattern, Settings};
 use ::ruff::tell_user;
+use ruff::linter::add_noqa_to_path;
 
 const CARGO_PKG_NAME: &str = env!("CARGO_PKG_NAME");
 const CARGO_PKG_VERSION: &str = env!("CARGO_PKG_VERSION");
@@ -27,6 +33,7 @@ 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)]
+#[clap(version)]
 struct Cli {
     #[clap(parse(from_os_str), value_hint = ValueHint::AnyPath, required = true)]
     files: Vec<PathBuf>,
@@ -51,15 +58,33 @@ struct Cli {
     /// List of error codes to enable.
     #[clap(long, multiple = true)]
     select: Vec<CheckCode>,
+    /// Like --select, but adds additional error codes on top of the selected ones.
+    #[clap(long, multiple = true)]
+    extend_select: Vec<CheckCode>,
     /// List of error codes to ignore.
     #[clap(long, multiple = true)]
     ignore: Vec<CheckCode>,
+    /// Like --ignore, but adds additional error codes on top of the ignored ones.
+    #[clap(long, multiple = true)]
+    extend_ignore: Vec<CheckCode>,
     /// List of paths, used to exclude files and/or directories from checks.
     #[clap(long, multiple = true)]
-    exclude: Vec<Pattern>,
+    exclude: Vec<String>,
     /// Like --exclude, but adds additional files and directories on top of the excluded ones.
     #[clap(long, multiple = true)]
-    extend_exclude: Vec<Pattern>,
+    extend_exclude: Vec<String>,
+    /// Output serialization format for error messages.
+    #[clap(long, arg_enum, default_value_t=SerializationFormat::Text)]
+    format: SerializationFormat,
+    /// See the files ruff will be run against with the current settings.
+    #[clap(long, action)]
+    show_files: bool,
+    /// See ruff's settings.
+    #[clap(long, action)]
+    show_settings: bool,
+    /// Enable automatic additions of noqa directives to failing lines.
+    #[clap(long, action)]
+    add_noqa: bool,
 }
 
 #[cfg(feature = "update-informer")]
@@ -86,6 +111,22 @@ fn check_for_updates() {
     }
 }
 
+fn show_settings(settings: &Settings) {
+    println!("{:#?}", settings);
+}
+
+fn show_files(files: &[PathBuf], settings: &Settings) {
+    let mut entries: Vec<DirEntry> = files
+        .iter()
+        .flat_map(|path| iter_python_files(path, &settings.exclude, &settings.extend_exclude))
+        .flatten()
+        .collect();
+    entries.sort_by(|a, b| a.path().cmp(b.path()));
+    for entry in entries {
+        println!("{}", entry.path().to_string_lossy());
+    }
+}
+
 fn run_once(
     files: &[PathBuf],
     settings: &Settings,
@@ -94,7 +135,7 @@ fn run_once(
 ) -> Result<Vec<Message>> {
     // Collect all the files to check.
     let start = Instant::now();
-    let paths: Vec<DirEntry> = files
+    let paths: Vec<Result<DirEntry, walkdir::Error>> = files
         .iter()
         .flat_map(|path| iter_python_files(path, &settings.exclude, &settings.extend_exclude))
         .collect();
@@ -105,16 +146,33 @@ fn run_once(
     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(),
-                    }]
+            match entry {
+                Ok(entry) => {
+                    let path = entry.path();
+                    lint_path(path, settings, &cache.into(), &autofix.into())
+                        .map_err(|e| (Some(path.to_owned()), e.to_string()))
+                }
+                Err(e) => Err((
+                    e.path().map(Path::to_owned),
+                    e.io_error()
+                        .map_or_else(|| e.to_string(), io::Error::to_string),
+                )),
+            }
+            .unwrap_or_else(|(path, message)| {
+                if let Some(path) = path {
+                    if settings.select.contains(&CheckCode::E902) {
+                        vec![Message {
+                            kind: CheckKind::IOError(message),
+                            fixed: false,
+                            location: Default::default(),
+                            filename: path.to_string_lossy().to_string(),
+                        }]
+                    } else {
+                        error!("Failed to check {}: {message}", path.to_string_lossy());
+                        vec![]
+                    }
                 } else {
-                    error!("Failed to check {}: {e:?}", entry.path().to_string_lossy());
+                    error!("{message}");
                     vec![]
                 }
             })
@@ -122,19 +180,6 @@ fn run_once(
         .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);
@@ -142,52 +187,33 @@ fn run_once(
     Ok(messages)
 }
 
-fn report_once(messages: &[Message]) -> Result<()> {
-    let (fixed, outstanding): (Vec<&Message>, Vec<&Message>) =
-        messages.iter().partition(|message| message.fixed);
-    let num_fixable = outstanding
+fn add_noqa(files: &[PathBuf], settings: &Settings) -> Result<usize> {
+    // Collect all the files to check.
+    let start = Instant::now();
+    let paths: Vec<Result<DirEntry, walkdir::Error>> = files
         .iter()
-        .filter(|message| message.kind.fixable())
-        .count();
+        .flat_map(|path| iter_python_files(path, &settings.exclude, &settings.extend_exclude))
+        .collect();
+    let duration = start.elapsed();
+    debug!("Identified files to lint in: {:?}", duration);
 
-    if !outstanding.is_empty() {
-        for message in &outstanding {
-            println!("{}", message);
-        }
-        println!();
-    }
+    let start = Instant::now();
+    let modifications: usize = paths
+        .par_iter()
+        .map(|entry| match entry {
+            Ok(entry) => {
+                let path = entry.path();
+                add_noqa_to_path(path, settings)
+            }
+            Err(_) => Ok(0),
+        })
+        .flatten()
+        .sum();
 
-    if !fixed.is_empty() {
-        println!(
-            "Found {} error(s) ({} fixed).",
-            outstanding.len(),
-            fixed.len()
-        );
-    } else {
-        println!("Found {} error(s).", outstanding.len());
-    }
+    let duration = start.elapsed();
+    debug!("Added noqa to files in: {:?}", duration);
 
-    if num_fixable > 0 {
-        println!("{num_fixable} potentially fixable with the --fix option.");
-    }
-
-    Ok(())
-}
-
-fn report_continuously(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(())
+    Ok(modifications)
 }
 
 fn inner_main() -> Result<ExitCode> {
@@ -195,32 +221,87 @@ fn inner_main() -> Result<ExitCode> {
 
     set_up_logging(cli.verbose)?;
 
-    let mut settings = Settings::from_paths(&cli.files);
+    // Find the project root and pyproject.toml.
+    let project_root = pyproject::find_project_root(&cli.files);
+    match &project_root {
+        Some(path) => debug!("Found project root at: {:?}", path),
+        None => debug!("Unable to identify project root; assuming current directory..."),
+    };
+    let pyproject = pyproject::find_pyproject_toml(&project_root);
+    match &pyproject {
+        Some(path) => debug!("Found pyproject.toml at: {:?}", path),
+        None => debug!("Unable to find pyproject.toml; using default settings..."),
+    };
+
+    // Parse the settings from the pyproject.toml and command-line arguments.
+    let exclude: Vec<FilePattern> = cli
+        .exclude
+        .iter()
+        .map(|path| FilePattern::from_user(path, &project_root))
+        .collect();
+    let extend_exclude: Vec<FilePattern> = cli
+        .extend_exclude
+        .iter()
+        .map(|path| FilePattern::from_user(path, &project_root))
+        .collect();
+
+    let mut settings = Settings::from_pyproject(pyproject, project_root);
+    if !exclude.is_empty() {
+        settings.exclude = exclude;
+    }
+    if !extend_exclude.is_empty() {
+        settings.extend_exclude = extend_exclude;
+    }
     if !cli.select.is_empty() {
+        settings.clear();
         settings.select(cli.select);
     }
+    if !cli.extend_select.is_empty() {
+        settings.select(cli.extend_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;
+    if !cli.extend_ignore.is_empty() {
+        settings.ignore(&cli.extend_ignore);
     }
 
+    if cli.show_settings && cli.show_files {
+        println!("Error: specify --show-settings or show-files (not both).");
+        return Ok(ExitCode::FAILURE);
+    }
+    if cli.show_settings {
+        show_settings(&settings);
+        return Ok(ExitCode::SUCCESS);
+    }
+    if cli.show_files {
+        show_files(&cli.files, &settings);
+        return Ok(ExitCode::SUCCESS);
+    }
+
+    cache::init()?;
+
+    let mut printer = Printer::new(cli.format, cli.verbose);
     if cli.watch {
         if cli.fix {
-            println!("Warning: --fix is not enabled in watch mode.")
+            println!("Warning: --fix is not enabled in watch mode.");
+        }
+
+        if cli.add_noqa {
+            println!("Warning: --no-qa 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.
-        clearscreen::clear()?;
+        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 {
-            report_continuously(&messages)?;
+            printer.write_continuously(&messages)?;
         }
 
         // Configure the file watcher.
@@ -235,12 +316,12 @@ fn inner_main() -> Result<ExitCode> {
                 Ok(e) => {
                     if let Some(path) = e.path {
                         if path.to_string_lossy().ends_with(".py") {
-                            clearscreen::clear()?;
+                            printer.clear_screen()?;
                             tell_user!("File change detected...\n");
 
                             let messages = run_once(&cli.files, &settings, !cli.no_cache, false)?;
                             if !cli.quiet {
-                                report_continuously(&messages)?;
+                                printer.write_continuously(&messages)?;
                             }
                         }
                     }
@@ -248,10 +329,15 @@ fn inner_main() -> Result<ExitCode> {
                 Err(e) => return Err(e.into()),
             }
         }
+    } else if cli.add_noqa {
+        let modifications = add_noqa(&cli.files, &settings)?;
+        if modifications > 0 {
+            println!("Added {modifications} noqa directives.");
+        }
     } else {
         let messages = run_once(&cli.files, &settings, !cli.no_cache, cli.fix)?;
         if !cli.quiet {
-            report_once(&messages)?;
+            printer.write_once(&messages)?;
         }
 
         #[cfg(feature = "update-informer")]

src/message.rs

@@ -1,11 +1,13 @@
 use std::cmp::Ordering;
 use std::fmt;
+use std::path::Path;
 
 use colored::Colorize;
 use rustpython_parser::ast::Location;
 use serde::{Deserialize, Serialize};
 
 use crate::checks::CheckKind;
+use crate::fs::relativize_path;
 
 #[derive(Debug, PartialEq, Eq, Serialize, Deserialize)]
 pub struct Message {
@@ -36,7 +38,8 @@ impl fmt::Display for Message {
         write!(
             f,
             "{}{}{}{}{}{} {} {}",
-            self.filename.white().bold(),
+            relativize_path(Path::new(&self.filename)).white().bold(),
+            // self.filename.white(),
             ":".cyan(),
             self.location.row(),
             ":".cyan(),

src/noqa.rs

@@ -0,0 +1,280 @@
+use std::cmp::{max, min};
+
+use crate::checks::{Check, CheckCode};
+use anyhow::Result;
+use once_cell::sync::Lazy;
+use regex::Regex;
+use rustpython_parser::lexer::{LexResult, Tok};
+use std::collections::{BTreeMap, BTreeSet};
+use std::fs;
+use std::path::Path;
+
+static NO_QA_REGEX: Lazy<Regex> = Lazy::new(|| {
+    Regex::new(r"(?i)(?P<noqa>\s*# noqa(?::\s?(?P<codes>([A-Z]+[0-9]+(?:[,\s]+)?)+))?)")
+        .expect("Invalid regex")
+});
+static SPLIT_COMMA_REGEX: Lazy<Regex> = Lazy::new(|| Regex::new(r"[,\s]").expect("Invalid regex"));
+
+#[derive(Debug)]
+pub enum Directive<'a> {
+    None,
+    All(usize),
+    Codes(usize, Vec<&'a str>),
+}
+
+pub fn extract_noqa_directive(line: &str) -> Directive {
+    match NO_QA_REGEX.captures(line) {
+        Some(caps) => match caps.name("noqa") {
+            Some(noqa) => match caps.name("codes") {
+                Some(codes) => Directive::Codes(
+                    noqa.start(),
+                    SPLIT_COMMA_REGEX
+                        .split(codes.as_str())
+                        .map(|code| code.trim())
+                        .filter(|code| !code.is_empty())
+                        .collect(),
+                ),
+                None => Directive::All(noqa.start()),
+            },
+            None => Directive::None,
+        },
+        None => Directive::None,
+    }
+}
+
+pub fn extract_noqa_line_for(lxr: &[LexResult]) -> Vec<usize> {
+    let mut noqa_line_for: Vec<usize> = vec![];
+
+    let mut last_is_string = false;
+    let mut last_seen = usize::MIN;
+    let mut min_line = usize::MAX;
+    let mut max_line = usize::MIN;
+
+    for (start, tok, end) in lxr.iter().flatten() {
+        if matches!(tok, Tok::EndOfFile) {
+            break;
+        }
+
+        if matches!(tok, Tok::Newline) {
+            min_line = min(min_line, start.row());
+            max_line = max(max_line, start.row());
+
+            // For now, we only care about preserving noqa directives across multi-line strings.
+            if last_is_string {
+                noqa_line_for.extend(vec![max_line; (max_line + 1) - min_line]);
+            } else {
+                for i in (min_line - 1)..(max_line) {
+                    noqa_line_for.push(i + 1);
+                }
+            }
+
+            min_line = usize::MAX;
+            max_line = usize::MIN;
+        } else {
+            // Handle empty lines.
+            if start.row() > last_seen {
+                for i in last_seen..(start.row() - 1) {
+                    noqa_line_for.push(i + 1);
+                }
+            }
+
+            min_line = min(min_line, start.row());
+            max_line = max(max_line, end.row());
+        }
+        last_seen = start.row();
+        last_is_string = matches!(tok, Tok::String { .. });
+    }
+
+    noqa_line_for
+}
+
+fn add_noqa_inner(
+    checks: &Vec<Check>,
+    contents: &str,
+    noqa_line_for: &[usize],
+) -> Result<(usize, String)> {
+    let lines: Vec<&str> = contents.lines().collect();
+    let mut matches_by_line: BTreeMap<usize, BTreeSet<&CheckCode>> = BTreeMap::new();
+    for lineno in 0..lines.len() {
+        let mut codes: BTreeSet<&CheckCode> = BTreeSet::new();
+        for check in checks {
+            if check.location.row() == lineno + 1 {
+                codes.insert(check.kind.code());
+            }
+        }
+
+        // Grab the noqa (logical) line number for the current (physical) line.
+        // If there are newlines at the end of the file, they won't be represented in
+        // `noqa_line_for`, so fallback to the current line.
+        let noqa_lineno = noqa_line_for
+            .get(lineno)
+            .map(|lineno| lineno - 1)
+            .unwrap_or(lineno);
+
+        if !codes.is_empty() {
+            let matches = matches_by_line
+                .entry(noqa_lineno)
+                .or_insert_with(BTreeSet::new);
+            matches.append(&mut codes);
+        }
+    }
+
+    let mut count: usize = 0;
+    let mut output = "".to_string();
+    for (lineno, line) in lines.iter().enumerate() {
+        match matches_by_line.get(&lineno) {
+            None => {
+                output.push_str(line);
+                output.push('\n');
+            }
+            Some(codes) => {
+                match extract_noqa_directive(line) {
+                    Directive::None => {
+                        output.push_str(line);
+                    }
+                    Directive::All(start) => output.push_str(&line[..start]),
+                    Directive::Codes(start, _) => output.push_str(&line[..start]),
+                };
+                let codes: Vec<&str> = codes.iter().map(|code| code.as_str()).collect();
+                output.push_str("  # noqa: ");
+                output.push_str(&codes.join(", "));
+                output.push('\n');
+                count += 1;
+            }
+        }
+    }
+
+    Ok((count, output))
+}
+
+pub fn add_noqa(
+    checks: &Vec<Check>,
+    contents: &str,
+    noqa_line_for: &[usize],
+    path: &Path,
+) -> Result<usize> {
+    let (count, output) = add_noqa_inner(checks, contents, noqa_line_for)?;
+    fs::write(path, output)?;
+    Ok(count)
+}
+
+#[cfg(test)]
+mod tests {
+    use crate::checks::{Check, CheckKind};
+    use anyhow::Result;
+    use rustpython_parser::ast::Location;
+    use rustpython_parser::lexer;
+    use rustpython_parser::lexer::LexResult;
+
+    use crate::noqa::{add_noqa_inner, extract_noqa_line_for};
+
+    #[test]
+    fn extraction() -> Result<()> {
+        let lxr: Vec<LexResult> = lexer::make_tokenizer(
+            "x = 1
+y = 2
+z = x + 1",
+        )
+        .collect();
+        println!("{:?}", extract_noqa_line_for(&lxr));
+        assert_eq!(extract_noqa_line_for(&lxr), vec![1, 2, 3]);
+
+        let lxr: Vec<LexResult> = lexer::make_tokenizer(
+            "
+x = 1
+y = 2
+z = x + 1",
+        )
+        .collect();
+        println!("{:?}", extract_noqa_line_for(&lxr));
+        assert_eq!(extract_noqa_line_for(&lxr), vec![1, 2, 3, 4]);
+
+        let lxr: Vec<LexResult> = lexer::make_tokenizer(
+            "x = 1
+y = 2
+z = x + 1
+        ",
+        )
+        .collect();
+        println!("{:?}", extract_noqa_line_for(&lxr));
+        assert_eq!(extract_noqa_line_for(&lxr), vec![1, 2, 3]);
+
+        let lxr: Vec<LexResult> = lexer::make_tokenizer(
+            "x = 1
+
+y = 2
+z = x + 1
+        ",
+        )
+        .collect();
+        println!("{:?}", extract_noqa_line_for(&lxr));
+        assert_eq!(extract_noqa_line_for(&lxr), vec![1, 2, 3, 4]);
+
+        let lxr: Vec<LexResult> = lexer::make_tokenizer(
+            "x = '''abc
+def
+ghi
+'''
+y = 2
+z = x + 1",
+        )
+        .collect();
+        assert_eq!(extract_noqa_line_for(&lxr), vec![4, 4, 4, 4, 5, 6]);
+
+        Ok(())
+    }
+
+    #[test]
+    fn modification() -> Result<()> {
+        let checks = vec![];
+        let contents = "x = 1";
+        let noqa_line_for = vec![1];
+        let (count, output) = add_noqa_inner(&checks, contents, &noqa_line_for)?;
+        assert_eq!(count, 0);
+        assert_eq!(output.trim(), contents.trim());
+
+        let checks = vec![Check::new(
+            CheckKind::UnusedVariable("x".to_string()),
+            Location::new(1, 1),
+        )];
+        let contents = "x = 1";
+        let noqa_line_for = vec![1];
+        let (count, output) = add_noqa_inner(&checks, contents, &noqa_line_for)?;
+        assert_eq!(count, 1);
+        assert_eq!(output.trim(), "x = 1  # noqa: F841".trim());
+
+        let checks = vec![
+            Check::new(
+                CheckKind::AmbiguousVariableName("x".to_string()),
+                Location::new(1, 1),
+            ),
+            Check::new(
+                CheckKind::UnusedVariable("x".to_string()),
+                Location::new(1, 1),
+            ),
+        ];
+        let contents = "x = 1  # noqa: E741";
+        let noqa_line_for = vec![1];
+        let (count, output) = add_noqa_inner(&checks, contents, &noqa_line_for)?;
+        assert_eq!(count, 1);
+        assert_eq!(output.trim(), "x = 1  # noqa: E741, F841".trim());
+
+        let checks = vec![
+            Check::new(
+                CheckKind::AmbiguousVariableName("x".to_string()),
+                Location::new(1, 1),
+            ),
+            Check::new(
+                CheckKind::UnusedVariable("x".to_string()),
+                Location::new(1, 1),
+            ),
+        ];
+        let contents = "x = 1  # noqa";
+        let noqa_line_for = vec![1];
+        let (count, output) = add_noqa_inner(&checks, contents, &noqa_line_for)?;
+        assert_eq!(count, 1);
+        assert_eq!(output.trim(), "x = 1  # noqa: E741, F841".trim());
+
+        Ok(())
+    }
+}

src/printer.rs

@@ -0,0 +1,80 @@
+use anyhow::Result;
+use clap::ValueEnum;
+use colored::Colorize;
+
+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,
+    verbose: bool,
+}
+
+impl Printer {
+    pub fn new(format: SerializationFormat, verbose: bool) -> Self {
+        Self { format, verbose }
+    }
+
+    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 if !outstanding.is_empty() || self.verbose {
+                    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

@@ -2,32 +2,30 @@ use std::path::{Path, PathBuf};
 
 use anyhow::Result;
 use common_path::common_path_all;
-use log::debug;
+use path_absolutize::Absolutize;
 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()
-                    }
-                }
+pub fn load_config(pyproject: &Option<PathBuf>) -> Config {
+    match pyproject {
+        Some(pyproject) => match parse_pyproject_toml(pyproject) {
+            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(),
+        None => {
+            println!("No pyproject.toml found.");
+            println!("Falling back to default configuration...");
+            Default::default()
+        }
     }
 }
 
@@ -35,8 +33,8 @@ pub fn load_config(paths: &[PathBuf]) -> Config {
 #[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 exclude: Option<Vec<String>>,
+    pub extend_exclude: Option<Vec<String>>,
     pub select: Option<Vec<CheckCode>>,
     pub ignore: Option<Vec<CheckCode>>,
 }
@@ -56,20 +54,34 @@ fn parse_pyproject_toml(path: &Path) -> Result<PyProject> {
     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);
+pub fn find_pyproject_toml(path: &Option<PathBuf>) -> Option<PathBuf> {
+    if let Some(path) = path {
+        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"))
+    let mut path = dirs::config_dir()?;
+    path.push("ruff");
+    path.push("pyproject.toml");
+    if path.is_file() {
+        Some(path)
+    } else {
+        None
+    }
 }
 
-fn find_project_root(sources: &[PathBuf]) -> Option<PathBuf> {
-    if let Some(prefix) = common_path_all(sources.iter().map(PathBuf::as_path)) {
+pub fn find_project_root(sources: &[PathBuf]) -> Option<PathBuf> {
+    let absolute_sources: Vec<PathBuf> = sources
+        .iter()
+        .flat_map(|source| source.absolutize().map(|path| path.to_path_buf()))
+        .collect();
+    if let Some(prefix) = common_path_all(absolute_sources.iter().map(PathBuf::as_path)) {
         for directory in prefix.ancestors() {
             if directory.join(".git").is_dir() {
                 return Some(directory.to_path_buf());
@@ -88,7 +100,8 @@ fn find_project_root(sources: &[PathBuf]) -> Option<PathBuf> {
 
 #[cfg(test)]
 mod tests {
-    use std::path::{Path, PathBuf};
+    use std::env::current_dir;
+    use std::path::PathBuf;
 
     use anyhow::Result;
 
@@ -160,7 +173,7 @@ exclude = ["foo.py"]
             Some(Tools {
                 ruff: Some(Config {
                     line_length: None,
-                    exclude: Some(vec![Path::new("foo.py").to_path_buf()]),
+                    exclude: Some(vec!["foo.py".to_string()]),
                     extend_exclude: None,
                     select: None,
                     ignore: None,
@@ -241,13 +254,15 @@ other-attribute = 1
 
     #[test]
     fn find_and_parse_pyproject_toml() -> Result<()> {
+        let cwd = current_dir()?;
         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"));
+        assert_eq!(project_root, cwd.join("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 path =
+            find_pyproject_toml(&Some(project_root)).expect("Unable to find pyproject.toml.");
+        assert_eq!(path, cwd.join("resources/test/fixtures/pyproject.toml"));
 
         let pyproject = parse_pyproject_toml(&path)?;
         let config = pyproject
@@ -260,53 +275,11 @@ other-attribute = 1
                 line_length: Some(88),
                 exclude: None,
                 extend_exclude: Some(vec![
-                    Path::new("excluded.py").to_path_buf(),
-                    Path::new("migrations").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,
+                    "excluded.py".to_string(),
+                    "migrations".to_string(),
+                    "directory/also_excluded.py".to_string(),
                 ]),
+                select: None,
                 ignore: None,
             }
         );

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 +1,73 @@
 use std::collections::BTreeSet;
 use std::hash::{Hash, Hasher};
-use std::path::PathBuf;
+use std::path::{Path, PathBuf};
 
 use glob::Pattern;
 use once_cell::sync::Lazy;
 
-use crate::checks::CheckCode;
+use crate::checks::{CheckCode, DEFAULT_CHECK_CODES};
+use crate::fs;
 use crate::pyproject::load_config;
 
+#[derive(Debug, Clone)]
+pub enum FilePattern {
+    Simple(&'static str),
+    Complex(Pattern, Option<Pattern>),
+}
+
+impl FilePattern {
+    pub fn from_user(pattern: &str, project_root: &Option<PathBuf>) -> Self {
+        let path = Path::new(pattern);
+        let absolute_path = match project_root {
+            Some(project_root) => fs::normalize_path_to(path, project_root),
+            None => fs::normalize_path(path),
+        };
+
+        let absolute = Pattern::new(&absolute_path.to_string_lossy()).expect("Invalid pattern.");
+        let basename = if !pattern.contains(std::path::MAIN_SEPARATOR) {
+            Some(Pattern::new(pattern).expect("Invalid pattern."))
+        } else {
+            None
+        };
+
+        FilePattern::Complex(absolute, basename)
+    }
+}
+
 #[derive(Debug)]
 pub struct Settings {
+    pub pyproject: Option<PathBuf>,
+    pub project_root: Option<PathBuf>,
     pub line_length: usize,
-    pub exclude: Vec<Pattern>,
-    pub extend_exclude: Vec<Pattern>,
+    pub exclude: Vec<FilePattern>,
+    pub extend_exclude: Vec<FilePattern>,
     pub select: BTreeSet<CheckCode>,
 }
 
+impl Settings {
+    pub fn for_rule(check_code: CheckCode) -> Self {
+        Self {
+            pyproject: None,
+            project_root: None,
+            line_length: 88,
+            exclude: vec![],
+            extend_exclude: vec![],
+            select: BTreeSet::from([check_code]),
+        }
+    }
+
+    pub fn for_rules(check_codes: Vec<CheckCode>) -> Self {
+        Self {
+            pyproject: None,
+            project_root: None,
+            line_length: 88,
+            exclude: vec![],
+            extend_exclude: vec![],
+            select: BTreeSet::from_iter(check_codes),
+        }
+    }
+}
+
 impl Hash for Settings {
     fn hash<H: Hasher>(&self, state: &mut H) {
         self.line_length.hash(state);
@@ -24,42 +76,42 @@ impl Hash for Settings {
         }
     }
 }
-static DEFAULT_EXCLUDE: Lazy<Vec<Pattern>> = Lazy::new(|| {
+
+static DEFAULT_EXCLUDE: Lazy<Vec<FilePattern>> = 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(".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(),
+        FilePattern::Simple(".bzr"),
+        FilePattern::Simple(".direnv"),
+        FilePattern::Simple(".eggs"),
+        FilePattern::Simple(".git"),
+        FilePattern::Simple(".hg"),
+        FilePattern::Simple(".mypy_cache"),
+        FilePattern::Simple(".nox"),
+        FilePattern::Simple(".pants.d"),
+        FilePattern::Simple(".ruff_cache"),
+        FilePattern::Simple(".svn"),
+        FilePattern::Simple(".tox"),
+        FilePattern::Simple(".venv"),
+        FilePattern::Simple("__pypackages__"),
+        FilePattern::Simple("_build"),
+        FilePattern::Simple("buck-out"),
+        FilePattern::Simple("build"),
+        FilePattern::Simple("dist"),
+        FilePattern::Simple("node_modules"),
+        FilePattern::Simple("venv"),
     ]
 });
 
 impl Settings {
-    pub fn from_paths(paths: &[PathBuf]) -> Self {
-        let config = load_config(paths);
+    pub fn from_pyproject(pyproject: Option<PathBuf>, project_root: Option<PathBuf>) -> Self {
+        let config = load_config(&pyproject);
         let mut settings = Settings {
             line_length: config.line_length.unwrap_or(88),
             exclude: config
                 .exclude
                 .map(|paths| {
                     paths
-                        .into_iter()
-                        .map(|path| {
-                            Pattern::new(&path.to_string_lossy()).expect("Invalid pattern.")
-                        })
+                        .iter()
+                        .map(|path| FilePattern::from_user(path, &project_root))
                         .collect()
                 })
                 .unwrap_or_else(|| DEFAULT_EXCLUDE.clone()),
@@ -67,59 +119,18 @@ impl Settings {
                 .extend_exclude
                 .map(|paths| {
                     paths
-                        .into_iter()
-                        .map(|path| {
-                            Pattern::new(&path.to_string_lossy()).expect("Invalid pattern.")
-                        })
+                        .iter()
+                        .map(|path| FilePattern::from_user(path, &project_root))
                         .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,
-                ]
-            })),
+            select: if let Some(select) = config.select {
+                BTreeSet::from_iter(select)
+            } else {
+                BTreeSet::from_iter(DEFAULT_CHECK_CODES)
+            },
+            pyproject,
+            project_root,
         };
         if let Some(ignore) = &config.ignore {
             settings.ignore(ignore);
@@ -127,8 +138,11 @@ impl Settings {
         settings
     }
 
-    pub fn select(&mut self, codes: Vec<CheckCode>) {
+    pub fn clear(&mut self) {
         self.select.clear();
+    }
+
+    pub fn select(&mut self, codes: Vec<CheckCode>) {
         for code in codes {
             self.select.insert(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

@@ -32,4 +32,22 @@ expression: checks
     row: 58
     column: 5
   fix: ~
+- kind:
+    UndefinedName: TOMATO
+  location:
+    row: 83
+    column: 11
+  fix: ~
+- kind:
+    UndefinedName: B
+  location:
+    row: 87
+    column: 7
+  fix: ~
+- kind:
+    UndefinedName: B
+  location:
+    row: 89
+    column: 7
+  fix: ~
 

src/snapshots/ruff__linter__tests__init.snap

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

src/snapshots/ruff__linter__tests__m001.snap

@@ -0,0 +1,89 @@
+---
+source: src/linter.rs
+expression: checks
+---
+- kind:
+    UnusedNOQA: ~
+  location:
+    row: 9
+    column: 10
+  fix:
+    content: ""
+    start:
+      row: 9
+      column: 10
+    end:
+      row: 9
+      column: 18
+    applied: false
+- kind:
+    UnusedNOQA: E501
+  location:
+    row: 13
+    column: 10
+  fix:
+    content: ""
+    start:
+      row: 13
+      column: 10
+    end:
+      row: 13
+      column: 24
+    applied: false
+- kind:
+    UnusedNOQA: E501
+  location:
+    row: 16
+    column: 10
+  fix:
+    content: "  # noqa: F841"
+    start:
+      row: 16
+      column: 10
+    end:
+      row: 16
+      column: 30
+    applied: false
+- kind:
+    UnusedNOQA: F841
+  location:
+    row: 41
+    column: 4
+  fix:
+    content: "  # noqa: E501"
+    start:
+      row: 41
+      column: 4
+    end:
+      row: 41
+      column: 24
+    applied: false
+- kind:
+    UnusedNOQA: E501
+  location:
+    row: 49
+    column: 4
+  fix:
+    content: ""
+    start:
+      row: 49
+      column: 4
+    end:
+      row: 49
+      column: 18
+    applied: false
+- kind:
+    UnusedNOQA: ~
+  location:
+    row: 57
+    column: 4
+  fix:
+    content: ""
+    start:
+      row: 57
+      column: 4
+    end:
+      row: 57
+      column: 12
+    applied: false
+