Bump version to 0.0.63

.editorconfig

@@ -0,0 +1,14 @@
+# Check http://editorconfig.org for more information
+# This is the main config file for this project:
+root = true
+
+[*]
+charset = utf-8
+trim_trailing_whitespace = true
+end_of_line = lf
+indent_style = space
+insert_final_newline = true
+indent_size = 2
+
+[*.{rs,py}]
+indent_size = 4

.github/workflows/release.yaml

@@ -16,7 +16,7 @@ env:
   PYTHON_VERSION: "3.7" # to build abi3 wheels
 
 jobs:
-  macos:
+  macos-x86_64:
     runs-on: macos-latest
     steps:
       - uses: actions/checkout@v3
@@ -39,6 +39,25 @@ jobs:
       - name: Install built wheel - x86_64
         run: |
           pip install dist/${{ env.PACKAGE_NAME }}-*.whl --force-reinstall
+      - name: Upload wheels
+        uses: actions/upload-artifact@v2
+        with:
+          name: wheels
+          path: dist
+  macos-universal:
+    runs-on: macos-latest
+    steps:
+      - uses: actions/checkout@v3
+      - uses: actions/setup-python@v4
+        with:
+          python-version: ${{ env.PYTHON_VERSION }}
+          architecture: x64
+      - name: Install Rust toolchain
+        uses: actions-rs/toolchain@v1
+        with:
+          toolchain: stable
+          profile: minimal
+          default: true
       - name: Build wheels - universal2
         uses: messense/maturin-action@v1
         with:
@@ -261,7 +280,8 @@ jobs:
     name: Release
     runs-on: ubuntu-latest
     needs:
-      - macos
+      - macos-universal
+      - macos-x86_64
       - windows
       - linux
       - linux-cross

.pre-commit-config.yaml

@@ -1,5 +1,10 @@
 repos:
-  - repo: https://github.com/charliermarsh/ruff
-    rev: v0.0.32
+  - repo: https://github.com/charliermarsh/ruff-pre-commit
+    rev: v0.0.40
     hooks:
       - id: lint
+
+  - repo: https://github.com/abravalheri/validate-pyproject
+    rev: v0.10.1
+    hooks:
+      - id: validate-pyproject

.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

CODE_OF_CONDUCT.md

@@ -0,0 +1,128 @@
+# Contributor Covenant Code of Conduct
+
+## Our Pledge
+
+We as members, contributors, and leaders pledge to make participation in our
+community a harassment-free experience for everyone, regardless of age, body
+size, visible or invisible disability, ethnicity, sex characteristics, gender
+identity and expression, level of experience, education, socio-economic status,
+nationality, personal appearance, race, religion, or sexual identity
+and orientation.
+
+We pledge to act and interact in ways that contribute to an open, welcoming,
+diverse, inclusive, and healthy community.
+
+## Our Standards
+
+Examples of behavior that contributes to a positive environment for our
+community include:
+
+* Demonstrating empathy and kindness toward other people
+* Being respectful of differing opinions, viewpoints, and experiences
+* Giving and gracefully accepting constructive feedback
+* Accepting responsibility and apologizing to those affected by our mistakes,
+  and learning from the experience
+* Focusing on what is best not just for us as individuals, but for the
+  overall community
+
+Examples of unacceptable behavior include:
+
+* The use of sexualized language or imagery, and sexual attention or
+  advances of any kind
+* Trolling, insulting or derogatory comments, and personal or political attacks
+* Public or private harassment
+* Publishing others' private information, such as a physical or email
+  address, without their explicit permission
+* Other conduct which could reasonably be considered inappropriate in a
+  professional setting
+
+## Enforcement Responsibilities
+
+Community leaders are responsible for clarifying and enforcing our standards of
+acceptable behavior and will take appropriate and fair corrective action in
+response to any behavior that they deem inappropriate, threatening, offensive,
+or harmful.
+
+Community leaders have the right and responsibility to remove, edit, or reject
+comments, commits, code, wiki edits, issues, and other contributions that are
+not aligned to this Code of Conduct, and will communicate reasons for moderation
+decisions when appropriate.
+
+## Scope
+
+This Code of Conduct applies within all community spaces, and also applies when
+an individual is officially representing the community in public spaces.
+Examples of representing our community include using an official e-mail address,
+posting via an official social media account, or acting as an appointed
+representative at an online or offline event.
+
+## Enforcement
+
+Instances of abusive, harassing, or otherwise unacceptable behavior may be
+reported to the community leaders responsible for enforcement at
+charlie.r.marsh@gmail.com.
+All complaints will be reviewed and investigated promptly and fairly.
+
+All community leaders are obligated to respect the privacy and security of the
+reporter of any incident.
+
+## Enforcement Guidelines
+
+Community leaders will follow these Community Impact Guidelines in determining
+the consequences for any action they deem in violation of this Code of Conduct:
+
+### 1. Correction
+
+**Community Impact**: Use of inappropriate language or other behavior deemed
+unprofessional or unwelcome in the community.
+
+**Consequence**: A private, written warning from community leaders, providing
+clarity around the nature of the violation and an explanation of why the
+behavior was inappropriate. A public apology may be requested.
+
+### 2. Warning
+
+**Community Impact**: A violation through a single incident or series
+of actions.
+
+**Consequence**: A warning with consequences for continued behavior. No
+interaction with the people involved, including unsolicited interaction with
+those enforcing the Code of Conduct, for a specified period of time. This
+includes avoiding interactions in community spaces as well as external channels
+like social media. Violating these terms may lead to a temporary or
+permanent ban.
+
+### 3. Temporary Ban
+
+**Community Impact**: A serious violation of community standards, including
+sustained inappropriate behavior.
+
+**Consequence**: A temporary ban from any sort of interaction or public
+communication with the community for a specified period of time. No public or
+private interaction with the people involved, including unsolicited interaction
+with those enforcing the Code of Conduct, is allowed during this period.
+Violating these terms may lead to a permanent ban.
+
+### 4. Permanent Ban
+
+**Community Impact**: Demonstrating a pattern of violation of community
+standards, including sustained inappropriate behavior,  harassment of an
+individual, or aggression toward or disparagement of classes of individuals.
+
+**Consequence**: A permanent ban from any sort of public interaction within
+the community.
+
+## Attribution
+
+This Code of Conduct is adapted from the [Contributor Covenant][homepage],
+version 2.0, available at
+https://www.contributor-covenant.org/version/2/0/code_of_conduct.html.
+
+Community Impact Guidelines were inspired by [Mozilla's code of conduct
+enforcement ladder](https://github.com/mozilla/diversity).
+
+[homepage]: https://www.contributor-covenant.org
+
+For answers to common questions about this code of conduct, see the FAQ at
+https://www.contributor-covenant.org/faq. Translations are available at
+https://www.contributor-covenant.org/translations.

CONTRIBUTING.md

@@ -0,0 +1,111 @@
+# Contributing to ruff
+
+Welcome! We're happy to have you here. Thank you in advance for your contribution to ruff.
+
+## The basics
+
+ruff welcomes contributions in the form of Pull Requests. For small changes (e.g., bug fixes), feel
+free to submit a PR. For larger changes (e.g., new lint rules, new functionality, new configuration
+options), consider submitting an [Issue](https://github.com/charliermarsh/ruff/issues) outlining
+your proposed change.
+
+### Prerequisites
+
+ruff is written in Rust (1.63.0). You'll need to install the
+[Rust toolchain](https://www.rust-lang.org/tools/install) for development.
+
+You'll also need [Insta](https://insta.rs/docs/) to update snapshot tests:
+
+```shell
+cargo install cargo-insta
+```
+
+### Development
+
+After cloning the repository, run ruff locally with:
+
+```shell
+cargo run resources/test/fixtures --no-cache
+```
+
+Prior to opening a pull request, ensure that your code has been auto-formatted, and that it passes
+both the lint and test validation checks:
+
+```shell
+cargo fmt     # Auto-formatting...
+cargo clippy  # Linting...
+cargo test    # Testing...
+```
+
+These checks will run on GitHub Actions when you open your Pull Request, but running them locally
+will save you time and expedite the merge process.
+
+Your Pull Request will be reviewed by a maintainer, which may involve a few rounds of iteration
+prior to merging.
+
+### Example: Adding a new lint rule
+
+There are three phases to adding a new lint rule:
+
+1. Define the rule in `src/checks.rs`.
+2. Define the _logic_ for triggering the rule in `src/check_ast.rs` (for AST-based checks)
+   or `src/check_lines.rs` (for text-based checks).
+3. Add a test fixture.
+
+To define the rule, open up `src/checks.rs`. You'll need to define both a `CheckCode` and
+`CheckKind`. As an example, you can grep for `E402` and `ModuleImportNotAtTopOfFile`, and follow the
+pattern implemented therein.
+
+To trigger the rule, you'll likely want to augment the logic in `src/check_ast.rs`, which defines
+the Python AST visitor, responsible for iterating over the abstract syntax tree and collecting
+lint-rule violations as it goes. Grep for the `Check::new` invocations to understand how other,
+similar rules are implemented.
+
+To add a test fixture, create a file under `resources/test/fixtures`, named to match the `CheckCode`
+you defined earlier (e.g., `E402.py`). This file should contain a variety of violations and
+non-violations designed to evaluate and demonstrate the behavior of your lint rule. Run ruff locally
+with (e.g.) `cargo run resources/test/fixtures/E402.py`. Once you're satisfied with the output,
+codify the behavior as a snapshot test by adding a new function to the `mod tests` section of
+`src/linter.rs`, like so:
+
+```rust
+#[test]
+fn e402() -> Result<()> {
+    let mut checks = check_path(
+        Path::new("./resources/test/fixtures/E402.py"),
+        &settings::Settings::for_rule(CheckCode::E402),
+        &fixer::Mode::Generate,
+    )?;
+    checks.sort_by_key(|check| check.location);
+    insta::assert_yaml_snapshot!(checks);
+    Ok(())
+}
+```
+
+Then, run `cargo test`. Your test will fail, but you'll be prompted to follow-up with
+`cargo insta review`. Accept the generated snapshot, then commit the snapshot file alongside the
+rest of your changes.
+
+### Example: Adding a new configuration option
+
+ruff's user-facing settings live in two places: first, the command-line options defined with
+[clap](https://docs.rs/clap/latest/clap/) via the `Cli` struct in `src/main.rs`; and second, the
+`Config` struct defined `src/pyproject.rs`, which is responsible for extracting user-defined
+settings from a `pyproject.toml` file.
+
+Ultimately, these two sources of configuration are merged into the `Settings` struct defined
+in `src/settings.rs`, which is then threaded through the codebase.
+
+To add a new configuration option, you'll likely want to _both_ add a CLI option to `src/main.rs`
+_and_ a `pyproject.toml` parameter to `src/pyproject.rs`. If you want to pattern-match against an
+existing example, grep for `dummy_variable_rgx`, which defines a regular expression to match against
+acceptable unused variables (e.g., `_`).
+
+## Release process
+
+As of now, ruff has an ad hoc release process: releases are cut with high frequency via GitHub
+Actions, which automatically generates the appropriate wheels across architectures and publishes
+them to [PyPI](https://pypi.org/project/ruff/).
+
+ruff follows the [semver](https://semver.org/) versioning standard. However, as pre-1.0 software,
+even patch releases may contain [non-backwards-compatible changes](https://semver.org/#spec-item-4).

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "ruff"
-version = "0.0.32"
+version = "0.0.63"
 edition = "2021"
 
 [lib]
@@ -11,7 +11,7 @@ anyhow = { version = "1.0.60" }
 bincode = { version = "1.3.3" }
 cacache = { version = "10.0.1" }
 chrono = { version = "0.4.21" }
-clap = { version = "3.2.16", features = ["derive"] }
+clap = { version = "4.0.1", features = ["derive"] }
 clearscreen = { version = "1.0.10" }
 colored = { version = "2.0.0" }
 common-path = { version = "1.0.0" }
@@ -19,19 +19,27 @@ dirs = { version = "4.0.0" }
 fern = { version = "0.6.1" }
 filetime = { version = "0.2.17" }
 glob = { version = "0.3.0" }
-itertools = "0.10.3"
-lazy_static = "1.4.0"
+itertools = { version = "0.10.5" }
+libcst = { git = "https://github.com/charliermarsh/LibCST", rev = "32a044c127668df44582f85699358e67803b0d73" }
 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-ast = { features = ["unparse"], git = "https://github.com/charliermarsh/RustPython.git", rev = "778ae2aeb521d0438d2a91bd11238bb5c2bf9d4f" }
+rustpython-parser = { features = ["lalrpop"], git = "https://github.com/charliermarsh/RustPython.git", rev = "778ae2aeb521d0438d2a91bd11238bb5c2bf9d4f" }
+rustpython-common = { git = "https://github.com/charliermarsh/RustPython.git", rev = "778ae2aeb521d0438d2a91bd11238bb5c2bf9d4f" }
 serde = { version = "1.0.143", features = ["derive"] }
 serde_json = { version = "1.0.83" }
 toml = { version = "0.5.9" }
 update-informer = { version = "0.5.0", default_features = false, features = ["pypi"], optional = true }
 walkdir = { version = "2.3.2" }
+strum = { version = "0.24.1", features = ["strum_macros"] }
+strum_macros = "0.24.3"
+
+[dev-dependencies]
+insta = { version = "1.19.1", features = ["yaml"] }
 
 [features]
 default = ["update-informer"]
@@ -42,3 +50,9 @@ panic = "abort"
 lto = "thin"
 codegen-units = 1
 opt-level = 3
+
+[profile.dev.package.insta]
+opt-level = 3
+
+[profile.dev.package.similar]
+opt-level = 3

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.
 
@@ -18,11 +20,9 @@ An extremely fast Python linter, written in Rust.
 - 🤝 Python 3.10 compatibility
 - 🛠️ `pyproject.toml` support
 - 📦 [ESLint](https://eslint.org/docs/latest/user-guide/command-line-interface#caching)-inspired cache support
-- 🔧 [ESLint](https://eslint.org/docs/latest/user-guide/command-line-interface#caching)-inspired `--fix` support
+- 🔧 [ESLint](https://eslint.org/docs/latest/user-guide/command-line-interface#--fix)-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: v0.0.32
-  hooks:
-    - id: lint
+  - repo: https://github.com/charliermarsh/ruff-pre-commit
+    rev: v0.0.48
+    hooks:
+      - id: lint
 ```
 
 ## Configuration
@@ -80,99 +80,261 @@ select = [
 Alternatively, on the command-line:
 
 ```shell
-ruff path/to/code/ --select F401 F403
+ruff path/to/code/ --select F401 --select F403
 ```
 
 See `ruff --help` for more:
 
 ```shell
-ruff (v0.0.32)
-An extremely fast Python linter.
+ruff: An extremely fast Python linter.
 
-USAGE:
-    ruff [OPTIONS] <FILES>...
+Usage: ruff [OPTIONS] <FILES>...
 
-ARGS:
-    <FILES>...
+Arguments:
+  <FILES>...
 
-OPTIONS:
-    -e, --exit-zero             Exit with status code "0", even upon detecting errors
-    -f, --fix                   Attempt to automatically fix lint errors
-    -h, --help                  Print help information
-        --ignore <IGNORE>...    Comma-separated 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>...    Comma-separated list of error codes to enable
-    -v, --verbose               Enable verbose logging
-    -w, --watch                 Run in watch mode by re-running whenever files change
+Options:
+  -v, --verbose
+          Enable verbose logging
+  -q, --quiet
+          Disable all logging (but still exit with status code "1" upon detecting errors)
+  -e, --exit-zero
+          Exit with status code "0", even upon detecting errors
+  -w, --watch
+          Run in watch mode by re-running whenever files change
+  -f, --fix
+          Attempt to automatically fix lint errors
+  -n, --no-cache
+          Disable cache reads
+      --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
+      --per-file-ignores <PER_FILE_IGNORES>
+          List of mappings from file pattern to code to exclude
+      --format <FORMAT>
+          Output serialization format for error messages [default: text] [possible values: text, json]
+      --show-files
+          See the files ruff will be run against with the current settings
+      --show-settings
+          See ruff's settings
+      --add-noqa
+          Enable automatic additions of noqa directives to failing lines
+      --dummy-variable-rgx <DUMMY_VARIABLE_RGX>
+          Regular expression matching the name of dummy variables
+      --target-version <TARGET_VERSION>
+          The minimum Python version that should be supported
+  -h, --help
+          Print help information
+  -V, --version
+          Print version information
 ```
 
+### 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 58 rules, give or take. At time of writing, ruff
-implements 28 rules. (Note that these 28 rules likely cover a disproportionate share of errors:
-unused imports, undefined variables, etc.)
+**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.)
 
-Of the unimplemented rules, ruff is missing:
+ruff also implements some of the most popular Flake8 plugins natively, including:
 
-- 15 rules related to string `.format` calls.
-- 6 rules related to misplaced `yield`, `break`, and `return` statements.
-- 3 rules related to syntax errors in doctests and annotations.
-- 2 rules related to redefining unused names.
-
-...along with a variety of others that don't fit neatly into any specific category.
+- [`flake8-builtins`](https://pypi.org/project/flake8-builtins/)
+- [`flake8-super`](https://pypi.org/project/flake8-super/)
+- [`flake8-print`](https://pypi.org/project/flake8-print/)
+- [`flake8-comprehensions`](https://pypi.org/project/flake8-comprehensions/) (partial)
+- [`pyupgrade`](https://pypi.org/project/pyupgrade/) (partial)
 
 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`.
+1. ruff does not yet support a few Python 3.9 and 3.10 language features, including structural
+   pattern matching and parenthesized context managers.
 2. Flake8 has a plugin architecture and supports writing custom lint rules.
-3. ruff does not yet support parenthesized context managers.
 
 ## Rules
 
-| Code | Name | Message |
-| ---- | ----- | ------- |
-| E402 | ModuleImportNotAtTopOfFile | Module level import not at top of file |
-| E501 | LineTooLong | Line too long |
-| E711 | NoneComparison | Comparison to `None` should be `cond is None` |
-| E712 | TrueFalseComparison | Comparison to `True` should be `cond is True` |
-| E713 | NotInTest | Test for membership should be `not in` |
-| E714 | NotIsTest | Test for object identity should be `is not` |
-| E731 | DoNotAssignLambda | Do not assign a lambda expression, use a def |
-| E902 | IOError | No such file or directory: `...` |
-| F401 | UnusedImport | `...` imported but unused |
-| F403 | ImportStarUsage | Unable to detect undefined names |
-| F541 | FStringMissingPlaceholders | f-string without any placeholders |
-| F601 | MultiValueRepeatedKeyLiteral | Dictionary key literal repeated |
-| F602 | MultiValueRepeatedKeyVariable | Dictionary key `...` repeated |
-| F621 | TooManyExpressionsInStarredAssignment | too many expressions in star-unpacking assignment |
-| F622 | TwoStarredExpressions | two starred expressions in assignment |
-| F631 | AssertTuple | Assert test is a non-empty tuple, which is always `True` |
-| F634 | IfTuple | If test is a tuple, which is always `True` |
-| F704 | YieldOutsideFunction | a `yield` or `yield from` statement outside of a function/method |
-| F706 | ReturnOutsideFunction | a `return` statement outside of a function/method |
-| F707 | DefaultExceptNotLast | an `except:` block as not the last exception handler |
-| F821 | UndefinedName | Undefined name `...` |
-| F822 | UndefinedExport | Undefined name `...` in `__all__` |
-| F823 | UndefinedLocal | Local variable `...` referenced before assignment |
-| F831 | DuplicateArgumentName | Duplicate argument name in function definition |
-| F841 | UnusedVariable | Local variable `...` is assigned to but never used |
-| F901 | RaiseNotImplemented | `raise NotImplemented` should be `raise NotImplementedError` |
-| R001 | UselessObjectInheritance | Class `...` inherits from object |
-| R002 | NoAssertEquals | `assertEquals` is deprecated, use `assertEqual` instead |
+The ✅ emoji indicates a rule is enabled by default.
+
+The 🛠 emoji indicates that a rule is automatically fixable by the `--fix` command-line option.
+
+| Code | Name | Message |     |     |
+| ---- | ---- | ------- | --- | --- |
+| E402 | ModuleImportNotAtTopOfFile | Module level import not at top of file | ✅ |  |
+| E501 | LineTooLong | Line too long (89 > 88 characters) | ✅ |  |
+| E711 | NoneComparison | Comparison to `None` should be `cond is None` | ✅ |  |
+| E712 | TrueFalseComparison | Comparison to `True` should be `cond is True` | ✅ |  |
+| E713 | NotInTest | Test for membership should be `not in` | ✅ |  |
+| E714 | NotIsTest | Test for object identity should be `is not` | ✅ |  |
+| E721 | TypeComparison | Do not compare types, use `isinstance()` | ✅ |  |
+| E722 | DoNotUseBareExcept | Do not use bare `except` | ✅ |  |
+| E731 | DoNotAssignLambda | Do not assign a lambda expression, use a def | ✅ |  |
+| E741 | AmbiguousVariableName | Ambiguous variable name: `...` | ✅ |  |
+| E742 | AmbiguousClassName | Ambiguous class name: `...` | ✅ |  |
+| E743 | AmbiguousFunctionName | Ambiguous function name: `...` | ✅ |  |
+| E902 | IOError | IOError: `...` | ✅ |  |
+| E999 | SyntaxError | SyntaxError: `...` | ✅ |  |
+| W292 | NoNewLineAtEndOfFile | No newline at end of file | ✅ |  |
+| F401 | UnusedImport | `...` imported but unused | ✅ | 🛠 |
+| 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 | ✅ |  |
+| F601 | MultiValueRepeatedKeyLiteral | Dictionary key literal repeated | ✅ |  |
+| F602 | MultiValueRepeatedKeyVariable | Dictionary key `...` repeated | ✅ |  |
+| F621 | ExpressionsInStarAssignment | Too many expressions in star-unpacking assignment | ✅ |  |
+| F622 | TwoStarredExpressions | Two starred expressions in assignment | ✅ |  |
+| F631 | AssertTuple | Assert test is a non-empty tuple, which is always `True` | ✅ |  |
+| F632 | IsLiteral | Use `==` and `!=` to compare constant literals | ✅ |  |
+| F633 | InvalidPrintSyntax | Use of `>>` is invalid with `print` function | ✅ |  |
+| F634 | IfTuple | If test is a tuple, which is always `True` | ✅ |  |
+| F701 | BreakOutsideLoop | `break` outside loop | ✅ |  |
+| F702 | ContinueOutsideLoop | `continue` not properly in loop | ✅ |  |
+| F704 | YieldOutsideFunction | `yield` or `yield from` statement outside of a function/method | ✅ |  |
+| F706 | ReturnOutsideFunction | `return` statement outside of a function/method | ✅ |  |
+| F707 | DefaultExceptNotLast | An `except:` block as not the last exception handler | ✅ |  |
+| F722 | ForwardAnnotationSyntaxError | Syntax error in forward annotation: `...` | ✅ |  |
+| F821 | UndefinedName | Undefined name `...` | ✅ |  |
+| F822 | UndefinedExport | Undefined name `...` in `__all__` | ✅ |  |
+| F823 | UndefinedLocal | Local variable `...` referenced before assignment | ✅ |  |
+| F831 | DuplicateArgumentName | Duplicate argument name in function definition | ✅ |  |
+| F841 | UnusedVariable | Local variable `...` is assigned to but never used | ✅ |  |
+| F901 | RaiseNotImplemented | `raise NotImplemented` should be `raise NotImplementedError` | ✅ |  |
+| A001 | BuiltinVariableShadowing | Variable `...` is shadowing a python builtin |  |  |
+| A002 | BuiltinArgumentShadowing | Argument `...` is shadowing a python builtin |  |  |
+| A003 | BuiltinAttributeShadowing | Class attribute `...` is shadowing a python builtin |  |  |
+| C400 | UnnecessaryGeneratorList | Unnecessary generator - rewrite as a list comprehension |  |  |
+| C401 | UnnecessaryGeneratorSet | Unnecessary generator - rewrite as a set comprehension |  |  |
+| C402 | UnnecessaryGeneratorDict | Unnecessary generator - rewrite as a dict comprehension |  |  |
+| C403 | UnnecessaryListComprehensionSet | Unnecessary list comprehension - rewrite as a set comprehension |  |  |
+| C404 | UnnecessaryListComprehensionDict | Unnecessary list comprehension - rewrite as a dict comprehension |  |  |
+| C405 | UnnecessaryLiteralSet | Unnecessary <list/tuple> literal - rewrite as a set literal |  |  |
+| C406 | UnnecessaryLiteralDict | Unnecessary <list/tuple> literal - rewrite as a dict literal |  |  |
+| C408 | UnnecessaryCollectionCall | Unnecessary <dict/list/tuple> call - rewrite as a literal |  |  |
+| SPR001 | SuperCallWithParameters | Use `super()` instead of `super(__class__, self)` |  | 🛠 |
+| T201 | PrintFound | `print` found |  | 🛠 |
+| T203 | PPrintFound | `pprint` found |  | 🛠 |
+| U001 | UselessMetaclassType | `__metaclass__ = type` is implied |  | 🛠 |
+| U002 | UnnecessaryAbspath | `abspath(__file__)` is unnecessary in Python 3.9 and later |  | 🛠 |
+| U003 | TypeOfPrimitive | Use `str` instead of `type(...)` |  | 🛠 |
+| U004 | UselessObjectInheritance | Class `...` inherits from object |  | 🛠 |
+| U005 | NoAssertEquals | `assertEquals` is deprecated, use `assertEqual` instead |  | 🛠 |
+| U006 | UsePEP585Annotation | Use `list` instead of `List` for type annotations |  | 🛠 |
+| U007 | UsePEP604Annotation | Use `X | Y` for type annotations |  | 🛠 |
+| M001 | UnusedNOQA | Unused `noqa` directive |  | 🛠 |
+
+## Integrations
+
+### PyCharm
+
+ruff can be installed as an [External Tool](https://www.jetbrains.com/help/pycharm/configuring-third-party-tools.html)
+in PyCharm. Open the Preferences pane, then navigate to "Tools", then "External Tools". From there,
+add a new tool with the following configuration:
+
+![Install ruff as an External Tool](https://user-images.githubusercontent.com/1309177/193155720-336e43f0-1a8d-46b4-bc12-e60f9ae01f7e.png)
+
+ruff should then appear as a runnable action:
+
+![ruff as a runnable action](https://user-images.githubusercontent.com/1309177/193156026-732b0aaf-3dd9-4549-9b4d-2de6d2168a33.png)
+
+### GitHub Actions
+
+GitHub Actions has everything you need to run ruff out-of-the-box:
+
+```yaml
+name: CI
+on: push
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v3
+      - name: Install Python
+        uses: actions/setup-python@v4
+        with:
+          python-version: "3.10"
+      - name: Install dependencies
+        run: |
+          python -m pip install --upgrade pip
+          pip install ruff
+      - name: Run ruff
+        run: ruff .
+```
 
 ## Development
 
@@ -206,9 +368,9 @@ git clone --branch 3.10 https://github.com/python/cpython.git resources/test/cpy
 Add this `pyproject.toml` to the CPython directory:
 
 ```toml
-[tool.linter]
+[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",
@@ -239,17 +401,21 @@ 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:
@@ -261,11 +427,8 @@ 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:
@@ -275,68 +438,65 @@ 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
 
 MIT
+
+## Contributing
+
+Contributions are welcome and hugely appreciated. To get started, check out the
+[contributing guidelines](https://github.com/charliermarsh/ruff/blob/main/CONTRIBUTING.md).

examples/generate_rules_table.rs

@@ -1,47 +1,26 @@
 /// Generate a Markdown-compatible table of supported lint rules.
-use ruff::checks::{CheckKind, RejectedCmpop};
+use strum::IntoEnumIterator;
+
+use ruff::checks::{CheckCode, DEFAULT_CHECK_CODES};
 
 fn main() {
-    let mut check_kinds: Vec<CheckKind> = vec![
-        CheckKind::AssertTuple,
-        CheckKind::DefaultExceptNotLast,
-        CheckKind::DoNotAssignLambda,
-        CheckKind::DuplicateArgumentName,
-        CheckKind::FStringMissingPlaceholders,
-        CheckKind::IOError("...".to_string()),
-        CheckKind::IfTuple,
-        CheckKind::ImportStarUsage,
-        CheckKind::LineTooLong,
-        CheckKind::ModuleImportNotAtTopOfFile,
-        CheckKind::MultiValueRepeatedKeyLiteral,
-        CheckKind::MultiValueRepeatedKeyVariable("...".to_string()),
-        CheckKind::NoAssertEquals,
-        CheckKind::NoneComparison(RejectedCmpop::Eq),
-        CheckKind::NotInTest,
-        CheckKind::NotIsTest,
-        CheckKind::RaiseNotImplemented,
-        CheckKind::ReturnOutsideFunction,
-        CheckKind::TooManyExpressionsInStarredAssignment,
-        CheckKind::TrueFalseComparison(true, RejectedCmpop::Eq),
-        CheckKind::TwoStarredExpressions,
-        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());
-
-    println!("| Code | Name | Message |");
-    println!("| ---- | ----- | ------- |");
-    for check_kind in check_kinds {
+    println!("| Code | Name | Message |     |     |");
+    println!("| ---- | ---- | ------- | --- | --- |");
+    for check_code in CheckCode::iter() {
+        let check_kind = check_code.kind();
+        let default_token = if DEFAULT_CHECK_CODES.contains(&check_code) {
+            "✅"
+        } else {
+            ""
+        };
+        let fix_token = if check_kind.fixable() { "🛠" } else { "" };
         println!(
-            "| {} | {} | {} |",
-            check_kind.code().as_str(),
-            check_kind.name(),
-            check_kind.body()
+            "| {} | {} | {} | {} | {} |",
+            check_kind.code().as_ref(),
+            check_kind.as_ref(),
+            check_kind.body(),
+            default_token,
+            fix_token
         );
     }
 }

examples/generate_source_code.rs

@@ -0,0 +1,26 @@
+use std::path::PathBuf;
+
+use anyhow::Result;
+use clap::Parser;
+use rustpython_parser::parser;
+
+use ruff::code_gen::SourceGenerator;
+use ruff::fs;
+
+#[derive(Debug, Parser)]
+struct Cli {
+    #[arg(required = true)]
+    file: PathBuf,
+}
+
+fn main() -> Result<()> {
+    let cli = Cli::parse();
+
+    let contents = fs::read_file(&cli.file)?;
+    let python_ast = parser::parse_program(&contents, &cli.file.to_string_lossy())?;
+    let mut generator = SourceGenerator::new();
+    generator.unparse_suite(&python_ast)?;
+    println!("{}", generator.generate()?);
+
+    Ok(())
+}

examples/print_ast.rs

@@ -2,14 +2,14 @@
 use std::path::PathBuf;
 
 use anyhow::Result;
-use clap::{Parser, ValueHint};
+use clap::Parser;
 use rustpython_parser::parser;
 
 use ruff::fs;
 
 #[derive(Debug, Parser)]
 struct Cli {
-    #[clap(parse(from_os_str), value_hint = ValueHint::FilePath, required = true)]
+    #[arg(required = true)]
     file: PathBuf,
 }
 

examples/print_tokens.rs

@@ -2,14 +2,14 @@
 use std::path::PathBuf;
 
 use anyhow::Result;
-use clap::{Parser, ValueHint};
+use clap::Parser;
 use rustpython_parser::lexer;
 
 use ruff::fs;
 
 #[derive(Debug, Parser)]
 struct Cli {
-    #[clap(parse(from_os_str), value_hint = ValueHint::FilePath, required = true)]
+    #[arg(required = true)]
     file: PathBuf,
 }
 

pyproject.toml

@@ -8,7 +8,6 @@ classifiers = [
     "License :: OSI Approved :: MIT License",
     "Operating System :: OS Independent",
     "Programming Language :: Python",
-    "Programming Language :: Python :: 3.6",
     "Programming Language :: Python :: 3.7",
     "Programming Language :: Python :: 3.8",
     "Programming Language :: Python :: 3.9",
@@ -19,10 +18,12 @@ classifiers = [
 ]
 author = "Charlie Marsh"
 author_email = "charlie.r.marsh@gmail.com"
-url = "https://github.com/charliermarsh/ruff"
 description = "An extremely fast Python linter, written in Rust."
 requires-python = ">=3.7"
 
+[project.urls]
+repository = "https://github.com/charliermarsh/ruff"
+
 [build-system]
 requires = ["maturin>=0.13,<0.14"]
 build-backend = "maturin"

resources/test/fixtures/A001.py

@@ -0,0 +1,27 @@
+import some as sum
+from some import other as int
+
+print = 1
+copyright: 'annotation' = 2
+(complex := 3)
+float = object = 4
+min, max = 5, 6
+
+def bytes():
+    pass
+
+class slice:
+    pass
+
+try:
+    ...
+except ImportError as ValueError:
+    ...
+
+for memoryview, *bytearray in []:
+    pass
+
+with open('file') as str, open('file2') as (all, any):
+    pass
+
+[0 for sum in ()]

resources/test/fixtures/A002.py

@@ -0,0 +1,9 @@
+def func1(str, /, type, *complex, Exception, **getattr):
+    pass
+
+
+async def func2(bytes):
+    pass
+
+
+map([], lambda float: ...)

resources/test/fixtures/A003.py

@@ -0,0 +1,8 @@
+class MyClass:
+    ImportError = 4
+
+    def __init__(self):
+        self.float = 5  # is fine
+
+    def str(self):
+        pass

resources/test/fixtures/C400.py

@@ -0,0 +1 @@
+x = list(x for x in range(3))

resources/test/fixtures/C401.py

@@ -0,0 +1 @@
+x = set(x for x in range(3))

resources/test/fixtures/C402.py

@@ -0,0 +1 @@
+d = dict((x, x) for x in range(3))

resources/test/fixtures/C403.py

@@ -0,0 +1 @@
+s = set([x for x in range(3)])

resources/test/fixtures/C404.py

@@ -0,0 +1 @@
+d = dict([(i, i) for i in range(3)])

resources/test/fixtures/C405.py

@@ -0,0 +1,5 @@
+s1 = set([1, 2])
+s2 = set((1, 2))
+s3 = set([])
+s4 = set(())
+s5 = set()

resources/test/fixtures/C406.py

@@ -0,0 +1,5 @@
+d1 = dict([(1, 2)])
+d2 = dict(((1, 2),))
+d3 = dict([])
+d4 = dict(())
+d5 = dict()

resources/test/fixtures/C408.py

@@ -0,0 +1,5 @@
+t = tuple()
+l = list()
+d1 = dict()
+d2 = dict(a=1)
+d3 = dict(**d2)

resources/test/fixtures/E402.py

@@ -1,4 +1,8 @@
 """Top-level docstring."""
+
+__all__ = ["y"]
+__version__: str = "0.1.0"
+
 import a
 
 try:

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/E711.py

@@ -1,11 +1,50 @@
-if var == None:
+#: E711
+if res == None:
+    pass
+#: E711
+if res != None:
+    pass
+#: E711
+if None == res:
+    pass
+#: E711
+if None != res:
+    pass
+#: E711
+if res[1] == None:
+    pass
+#: E711
+if res[1] != None:
+    pass
+#: E711
+if None != res[1]:
+    pass
+#: E711
+if None == res[1]:
     pass
 
-if None != var:
+#: Okay
+if x not in y:
     pass
 
-if var is None:
+if not (X in Y or X is Z):
     pass
 
-if None is not var:
+if not (X in Y):
     pass
+
+if x is not y:
+    pass
+
+if X is not Y is not Z:
+    pass
+
+if TrueElement.get_element(True) == TrueElement.get_element(False):
+    pass
+
+if (True) == TrueElement or x == TrueElement:
+    pass
+
+assert (not foo) in bar
+assert {"x": not foo} in bar
+assert [42, not foo] in bar

resources/test/fixtures/E712.py

@@ -1,14 +1,46 @@
-if var == True:
+#: E712
+if res == True:
+    pass
+#: E712
+if res != False:
+    pass
+#: E712
+if True != res:
+    pass
+#: E712
+if False == res:
+    pass
+#: E712
+if res[1] == True:
+    pass
+#: E712
+if res[1] != False:
+    pass
+#: E712
+var = 1 if cond == True else -1 if cond == False else cond
+#: E712
+if (True) == TrueElement or x == TrueElement:
     pass
 
-if False != var:
+#: Okay
+if x not in y:
     pass
 
-if var != False != True:
+if not (X in Y or X is Z):
     pass
 
-if var is True:
+if not (X in Y):
     pass
 
-if False is not var:
+if x is not y:
     pass
+
+if X is not Y is not Z:
+    pass
+
+if TrueElement.get_element(True) == TrueElement.get_element(False):
+    pass
+
+assert (not foo) in bar
+assert {"x": not foo} in bar
+assert [42, not foo] in bar

resources/test/fixtures/E713.py

@@ -1,7 +1,38 @@
-my_list = [1, 2, 3]
-if not num in my_list:
-    print(num)
+#: E713
+if not X in Y:
+    pass
+#: E713
+if not X.B in Y:
+    pass
+#: E713
+if not X in Y and Z == "zero":
+    pass
+#: E713
+if X == "zero" or not Y in Z:
+    pass
+#: E713
+if not (X in Y):
+    pass
 
-my_list = [1, 2, 3]
-if num not in my_list:
-    print(num)
+#: Okay
+if x not in y:
+    pass
+
+if not (X in Y or X is Z):
+    pass
+
+if x is not y:
+    pass
+
+if X is not Y is not Z:
+    pass
+
+if TrueElement.get_element(True) == TrueElement.get_element(False):
+    pass
+
+if (True) == TrueElement or x == TrueElement:
+    pass
+
+assert (not foo) in bar
+assert {"x": not foo} in bar
+assert [42, not foo] in bar

resources/test/fixtures/E714.py

@@ -1,5 +1,38 @@
-if not user is None:
-    print(user.name)
+#: E714
+if not X is Y:
+    pass
+#: E714
+if not X.B is Y:
+    pass
+#: E714
+if not X is Y is not Z:
+    pass
 
-if user is not None:
-    print(user.name)
+#: Okay
+if not X is not Y:
+    pass
+
+if x not in y:
+    pass
+
+if not (X in Y or X is Z):
+    pass
+
+if not (X in Y):
+    pass
+
+if x is not y:
+    pass
+
+if X is not Y is not Z:
+    pass
+
+if TrueElement.get_element(True) == TrueElement.get_element(False):
+    pass
+
+if (True) == TrueElement or x == TrueElement:
+    pass
+
+assert (not foo) in bar
+assert {"x": not foo} in bar
+assert [42, not foo] in bar

resources/test/fixtures/E721.py

@@ -0,0 +1,54 @@
+#: E721
+if type(res) == type(42):
+    pass
+#: E721
+if type(res) != type(""):
+    pass
+#: E721
+import types
+
+if res == types.IntType:
+    pass
+#: E721
+import types
+
+if type(res) is not types.ListType:
+    pass
+#: E721
+assert type(res) == type(False) or type(res) == type(None)
+#: E721
+assert type(res) == type([])
+#: E721
+assert type(res) == type(())
+#: E721
+assert type(res) == type((0,))
+#: E721
+assert type(res) == type((0))
+#: E721
+assert type(res) != type((1,))
+#: E721
+assert type(res) is type((1,))
+#: E721
+assert type(res) is not type((1,))
+#: E211 E721
+assert type(res) == type(
+    [
+        2,
+    ]
+)
+#: E201 E201 E202 E721
+assert type(res) == type(())
+#: E201 E202 E721
+assert type(res) == type((0,))
+
+#: Okay
+import types
+
+if isinstance(res, int):
+    pass
+if isinstance(res, str):
+    pass
+if isinstance(res, types.MethodType):
+    pass
+if type(a) != type(b) or type(a) == type(ccc):
+    pass

resources/test/fixtures/E722.py

@@ -0,0 +1,33 @@
+#: E722
+try:
+    pass
+except:
+    pass
+#: E722
+try:
+    pass
+except Exception:
+    pass
+except:
+    pass
+#: E722
+try:
+    pass
+except:
+    pass
+#: Okay
+fake_code = """"
+try:
+    do_something()
+except:
+    pass
+"""
+try:
+    pass
+except Exception:
+    pass
+#: Okay
+from . import compute_type
+
+if compute_type(foo) == 5:
+    pass

resources/test/fixtures/E731.py

@@ -1,6 +1,21 @@
-from typing import Callable, Iterable
+#: E731
+f = lambda x: 2 * x
+#: E731
+f = lambda x: 2 * x
+#: E731
+while False:
+    this = lambda y, z: 2 * x
 
-a = lambda x: x**2
-b = map(lambda x: 2 * x, range(3))
-c: Callable = lambda x: x**2
-d: Iterable = map(lambda x: 2 * x, range(3))
+
+f = object()
+#: E731
+f.method = lambda: "Method"
+
+f = {}
+#: E731
+f["a"] = lambda x: x ** 2
+
+f = []
+f.append(lambda x: x ** 2)
+
+lambda: "no-op"

resources/test/fixtures/E741.py

@@ -0,0 +1,75 @@
+from contextlib import contextmanager
+
+l = 0
+I = 0
+O = 0
+l: int = 0
+
+a, l = 0, 1
+[a, l] = 0, 1
+a, *l = 0, 1, 2
+a = l = 0
+
+o = 0
+i = 0
+
+for l in range(3):
+    pass
+
+
+for a, l in zip(range(3), range(3)):
+    pass
+
+
+def f1():
+    global l
+    l = 0
+
+
+def f2():
+    l = 0
+
+    def f3():
+        nonlocal l
+        l = 1
+
+    f3()
+    return l
+
+
+def f4(l, /, I):
+    return l, I, O
+
+
+def f5(l=0, *, I=1):
+    return l, I
+
+
+def f6(*l, **I):
+    return l, I
+
+
+@contextmanager
+def ctx1():
+    yield 0
+
+
+with ctx1() as l:
+    pass
+
+
+@contextmanager
+def ctx2():
+    yield 0, 1
+
+
+with ctx2() as (a, l):
+    pass
+
+try:
+    pass
+except ValueError as l:
+    pass
+
+if (l := 5) > 0:
+    pass

resources/test/fixtures/E742.py

@@ -0,0 +1,14 @@
+class l:
+    pass
+
+
+class I:
+    pass
+
+
+class O:
+    pass
+
+
+class X:
+    pass

resources/test/fixtures/E743.py

@@ -0,0 +1,15 @@
+def l():
+    pass
+
+
+def I():
+    pass
+
+
+class X:
+    def O(self):
+        pass
+
+
+def x():
+    pass

resources/test/fixtures/E999.py

@@ -0,0 +1,2 @@
+def x():
+

resources/test/fixtures/F401.py

@@ -1,6 +1,5 @@
 from __future__ import all_feature_names
-import os
-import functools
+import functools, os
 from datetime import datetime
 from collections import (
     Counter,
@@ -11,14 +10,36 @@ import multiprocessing.pool
 import multiprocessing.process
 import logging.config
 import logging.handlers
-from typing import TYPING_CHECK, NamedTuple, Dict, Type, TypeVar, List, Set, Union, cast
+from typing import (
+    TYPE_CHECKING,
+    NamedTuple,
+    Dict,
+    Type,
+    TypeVar,
+    List,
+    Set,
+    Union,
+    cast,
+)
+from dataclasses import MISSING, field
 
 from blah import ClassA, ClassB, ClassC
 
-if TYPING_CHECK:
+if TYPE_CHECKING:
     from models import Fruit, Nut, Vegetable
 
 
+if TYPE_CHECKING:
+    import shelve
+    import importlib
+
+if TYPE_CHECKING:
+    """Hello, world!"""
+    import pathlib
+
+    z = 1
+
+
 class X:
     datetime: datetime
     foo: Type["NamedTuple"]
@@ -28,6 +49,9 @@ class X:
         y = Counter()
         z = multiprocessing.pool.ThreadPool()
 
+    def b(self) -> None:
+        import pickle
+
 
 __all__ = ["ClassA"] + ["ClassB"]
 __all__ += ["ClassC"]
@@ -39,3 +63,5 @@ Z = TypeVar("Z", "List", "Set")
 a = list["Fruit"]
 b = Union["Nut", None]
 c = cast("Vegetable", b)
+
+Field = lambda default=MISSING: field(default=default)

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/F404.py

@@ -0,0 +1,7 @@
+from __future__ import print_function
+"""Docstring"""
+from __future__ import absolute_import
+
+from collections import namedtuple
+
+from __future__ import print_function

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/F406.py

@@ -0,0 +1,9 @@
+from F634 import *
+
+
+def f():
+    from F634 import *
+
+
+class F:
+    from F634 import *

resources/test/fixtures/F407.py

@@ -0,0 +1,2 @@
+from __future__ import print_function
+from __future__ import non_existent_feature

resources/test/fixtures/F632.py

@@ -0,0 +1,5 @@
+if x is "abc":
+    pass
+
+if 123 is not y:
+    pass

resources/test/fixtures/F633.py

@@ -0,0 +1,4 @@
+from __future__ import print_function
+import sys
+
+print >> sys.stderr, "Hello"

resources/test/fixtures/F701.py

@@ -0,0 +1,23 @@
+for i in range(10):
+    break
+else:
+    break
+
+i = 0
+while i < 10:
+    i += 1
+    break
+
+
+def f():
+    for i in range(10):
+        break
+
+    break
+
+
+class Foo:
+    break
+
+
+break

resources/test/fixtures/F702.py

@@ -0,0 +1,23 @@
+for i in range(10):
+    continue
+else:
+    continue
+
+i = 0
+while i < 10:
+    i += 1
+    continue
+
+
+def f():
+    for i in range(10):
+        continue
+
+    continue
+
+
+class Foo:
+    continue
+
+
+continue

resources/test/fixtures/F722.py

@@ -0,0 +1,10 @@
+class A:
+    pass
+
+
+def f() -> "A":
+    pass
+
+
+def g() -> "///":
+    pass

resources/test/fixtures/F821.py

@@ -77,3 +77,48 @@ 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}'
+)
+
+
+from typing import Annotated, Literal
+
+
+def arbitrary_callable() -> None:
+    ...
+
+
+class PEP593Test:
+    field: Annotated[
+        int,
+        "base64",
+        arbitrary_callable(),
+        123,
+        (1, 2, 3),
+    ]
+    field_with_stringified_type: Annotated[
+        "PEP593Test",
+        123,
+    ]
+    field_with_undefined_stringified_type: Annotated[
+        "PEP593Test123",
+        123,
+    ]
+    field_with_nested_subscript: Annotated[
+        dict[Literal["foo"], str],
+        123,
+    ]
+    field_with_undefined_nested_subscript: Annotated[
+        dict["foo", "bar"],  # Expected to fail as undefined.
+        123,
+    ]

resources/test/fixtures/F841.py

@@ -10,7 +10,28 @@ except ValueError as e:
     print(e)
 
 
-def f():
+def f1():
     x = 1
     y = 2
     z = x + y
+
+
+def f2():
+    foo = (1, 2)
+    (a, b) = (1, 2)
+
+    bar = (1, 2)
+    (c, d) = bar
+
+    (x, y) = baz = bar
+
+
+def f3():
+    locals()
+    x = 1
+
+
+def f4():
+    _ = 1
+    __ = 1
+    _discarded = 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/SPR001.py

@@ -0,0 +1,65 @@
+class Parent:
+    def method(self):
+        pass
+
+    def wrong(self):
+        pass
+
+
+class Child(Parent):
+    def method(self):
+        parent = super()  # ok
+        super().method()  # ok
+        Parent.method(self)  # ok
+        Parent.super(1, 2)  # ok
+
+    def wrong(self):
+        parent = super(Child, self)  # wrong
+        super(Child, self).method  # wrong
+        super(
+            Child,
+            self,
+        ).method()  # wrong
+
+
+class BaseClass:
+    def f(self):
+        print("f")
+
+
+def defined_outside(self):
+    super(MyClass, self).f()  # CANNOT use super()
+
+
+class MyClass(BaseClass):
+    def normal(self):
+        super(MyClass, self).f()  # can use super()
+        super().f()
+
+    def different_argument(self, other):
+        super(MyClass, other).f()  # CANNOT use super()
+
+    def comprehension_scope(self):
+        [super(MyClass, self).f() for x in [1]]  # CANNOT use super()
+
+    def inner_functions(self):
+        def outer_argument():
+            super(MyClass, self).f()  # CANNOT use super()
+
+        def inner_argument(self):
+            super(MyClass, self).f()  # can use super()
+            super().f()
+
+        outer_argument()
+        inner_argument(self)
+
+    def inner_class(self):
+        class InnerClass:
+            super(MyClass, self).f()  # CANNOT use super()
+
+            def method(inner_self):
+                super(MyClass, self).f()  # CANNOT use super()
+
+        InnerClass().method()
+
+    defined_outside = defined_outside

resources/test/fixtures/T201.py

@@ -0,0 +1 @@
+print("Hello, world!")  # T201

resources/test/fixtures/T203.py

@@ -0,0 +1,10 @@
+from pprint import pprint
+
+pprint("Hello, world!")  # T203
+
+
+import pprint
+
+pprint.pprint("Hello, world!")  # T203
+
+pprint.pformat("Hello, world!")

resources/test/fixtures/U001.py

@@ -0,0 +1,13 @@
+class A:
+    __metaclass__ = type
+
+
+class B:
+    __metaclass__ = type
+
+    def __init__(self) -> None:
+        pass
+
+
+class C(metaclass=type):
+    pass

resources/test/fixtures/U002.py

@@ -0,0 +1,15 @@
+from os.path import abspath
+
+x = abspath(__file__)
+
+
+import os
+
+
+y = os.path.abspath(__file__)
+
+
+from os import path
+
+
+z = path.abspath(__file__)

resources/test/fixtures/U003.py

@@ -0,0 +1,5 @@
+type('')
+type(b'')
+type(0)
+type(0.)
+type(0j)

resources/test/fixtures/U006.py

@@ -0,0 +1,12 @@
+from typing import List
+
+
+def f(x: List[str]) -> None:
+    ...
+
+
+import typing
+
+
+def f(x: typing.List[str]) -> None:
+    ...

resources/test/fixtures/U007.py

@@ -0,0 +1,40 @@
+from typing import Optional
+
+
+def f(x: Optional[str]) -> None:
+    ...
+
+
+import typing
+
+
+def f(x: typing.Optional[str]) -> None:
+    ...
+
+
+from typing import Union
+
+
+def f(x: Union[str, int, Union[float, bytes]]) -> None:
+    ...
+
+
+import typing
+
+
+def f(x: typing.Union[str, int]) -> None:
+    ...
+
+
+from typing import Union
+
+
+def f(x: "Union[str, int, Union[float, bytes]]") -> None:
+    ...
+
+
+import typing
+
+
+def f(x: "typing.Union[str, int]") -> None:
+    ...

resources/test/fixtures/W292_0.py

@@ -0,0 +1,2 @@
+def fn() -> None:
+    pass

resources/test/fixtures/W292_1.py

@@ -0,0 +1,2 @@
+def fn() -> None:
+    pass  # noqa: W292

resources/test/fixtures/W292_2.py

@@ -0,0 +1,2 @@
+def fn() -> None:
+    pass

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/future_annotations.py

@@ -0,0 +1,30 @@
+from __future__ import annotations
+
+from dataclasses import dataclass
+
+from models import (
+    Fruit,
+    Nut,
+)
+
+
+@dataclass
+class Foo:
+    x: int
+    y: int
+
+    @classmethod
+    def a(cls) -> Foo:
+        return cls(x=0, y=0)
+
+    @classmethod
+    def b(cls) -> "Foo":
+        return cls(x=0, y=0)
+
+    @classmethod
+    def c(cls) -> Bar:
+        return cls(x=0, y=0)
+
+    @classmethod
+    def d(cls) -> Fruit:
+        return cls(x=0, y=0)

resources/test/fixtures/pyproject.toml

@@ -1,33 +1,7 @@
 [tool.ruff]
 line-length = 88
-exclude = ["excluded.py", "**/migrations"]
-select = [
-    "E402",
-    "E501",
-    "E711",
-    "E712",
-    "E713",
-    "E714",
-    "E731",
-    "E902",
-    "F401",
-    "F403",
-    "F541",
-    "F601",
-    "F602",
-    "F621",
-    "F622",
-    "F631",
-    "F634",
-    "F704",
-    "F706",
-    "F707",
-    "F821",
-    "F822",
-    "F823",
-    "F831",
-    "F841",
-    "F901",
-    "R001",
-    "R002",
+extend-exclude = [
+    "excluded.py",
+    "migrations",
+    "directory/also_excluded.py",
 ]

src/ast.rs

@@ -1,4 +1,5 @@
 pub mod checks;
+pub mod helpers;
 pub mod operations;
 pub mod relocate;
 pub mod types;

src/ast/helpers.rs

@@ -0,0 +1,74 @@
+use once_cell::sync::Lazy;
+use regex::Regex;
+use rustpython_ast::{Expr, ExprKind, StmtKind};
+
+use crate::python::typing;
+
+static DUNDER_REGEX: Lazy<Regex> = Lazy::new(|| Regex::new(r"__[^\s]+__").unwrap());
+
+pub enum SubscriptKind {
+    AnnotatedSubscript,
+    PEP593AnnotatedSubscript,
+}
+
+pub fn match_annotated_subscript(expr: &Expr) -> Option<SubscriptKind> {
+    match &expr.node {
+        ExprKind::Attribute { attr, .. } => {
+            if typing::is_annotated_subscript(attr) {
+                Some(SubscriptKind::AnnotatedSubscript)
+            } else if typing::is_pep593_annotated_subscript(attr) {
+                Some(SubscriptKind::PEP593AnnotatedSubscript)
+            } else {
+                None
+            }
+        }
+        ExprKind::Name { id, .. } => {
+            if typing::is_annotated_subscript(id) {
+                Some(SubscriptKind::AnnotatedSubscript)
+            } else if typing::is_pep593_annotated_subscript(id) {
+                Some(SubscriptKind::PEP593AnnotatedSubscript)
+            } else {
+                None
+            }
+        }
+        _ => None,
+    }
+}
+
+pub fn is_assignment_to_a_dunder(node: &StmtKind) -> bool {
+    // Check whether it's an assignment to a dunder, with or without a type annotation.
+    // This is what pycodestyle (as of 2.9.1) does.
+    match node {
+        StmtKind::Assign {
+            targets,
+            value: _,
+            type_comment: _,
+        } => {
+            if targets.len() != 1 {
+                return false;
+            }
+            match &targets[0].node {
+                ExprKind::Name { id, ctx: _ } => DUNDER_REGEX.is_match(id),
+                _ => false,
+            }
+        }
+        StmtKind::AnnAssign {
+            target,
+            annotation: _,
+            value: _,
+            simple: _,
+        } => match &target.node {
+            ExprKind::Name { id, ctx: _ } => DUNDER_REGEX.is_match(id),
+            _ => false,
+        },
+        _ => false,
+    }
+}
+
+pub fn match_name_or_attr(expr: &Expr, target: &str) -> bool {
+    match &expr.node {
+        ExprKind::Attribute { attr, .. } => target == attr,
+        ExprKind::Name { id, .. } => target == id,
+        _ => false,
+    }
+}

src/ast/operations.rs

@@ -1,6 +1,6 @@
 use rustpython_parser::ast::{Constant, Expr, ExprKind, Location, Stmt, StmtKind};
 
-use crate::ast::types::{BindingKind, Scope};
+use crate::ast::types::{BindingKind, Range, Scope};
 
 /// Extract the names bound to a given __all__ assignment.
 pub fn extract_all_names(stmt: &Stmt, scope: &Scope) -> Vec<String> {
@@ -22,7 +22,7 @@ pub fn extract_all_names(stmt: &Stmt, scope: &Scope) -> Vec<String> {
     if let StmtKind::AugAssign { .. } = &stmt.node {
         if let Some(binding) = scope.values.get("__all__") {
             if let BindingKind::Export(existing) = &binding.kind {
-                names.extend(existing.clone());
+                names.extend_from_slice(existing);
             }
         }
     }
@@ -66,6 +66,58 @@ pub fn extract_all_names(stmt: &Stmt, scope: &Scope) -> Vec<String> {
     names
 }
 
+/// Check if a node is parent of a conditional branch.
+pub fn on_conditional_branch(parent_stack: &[usize], parents: &[&Stmt]) -> bool {
+    for index in parent_stack.iter().rev() {
+        let parent = parents[*index];
+        if matches!(parent.node, StmtKind::If { .. } | StmtKind::While { .. }) {
+            return true;
+        }
+        if let StmtKind::Expr { value } = &parent.node {
+            if matches!(value.node, ExprKind::IfExp { .. }) {
+                return true;
+            }
+        }
+    }
+
+    false
+}
+
+/// Check if a node is in a nested block.
+pub fn in_nested_block(parent_stack: &[usize], parents: &[&Stmt]) -> bool {
+    for index in parent_stack.iter().rev() {
+        let parent = parents[*index];
+        if matches!(
+            parent.node,
+            StmtKind::Try { .. } | StmtKind::If { .. } | StmtKind::With { .. }
+        ) {
+            return true;
+        }
+    }
+
+    false
+}
+
+/// Check if a node represents an unpacking assignment.
+pub fn is_unpacking_assignment(stmt: &Stmt) -> bool {
+    if let StmtKind::Assign { targets, value, .. } = &stmt.node {
+        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,
+            _ => {}
+        }
+        return true;
+    }
+    false
+}
+
 /// Struct used to efficiently slice source code at (row, column) Locations.
 pub struct SourceCodeLocator<'a> {
     content: &'a str,
@@ -82,7 +134,7 @@ impl<'a> SourceCodeLocator<'a> {
         }
     }
 
-    pub fn slice_source_code(&mut self, location: &Location) -> &'a str {
+    pub fn slice_source_code_at(&mut self, location: &Location) -> &'a str {
         if !self.initialized {
             let mut offset = 0;
             for i in self.content.lines() {
@@ -95,4 +147,19 @@ impl<'a> SourceCodeLocator<'a> {
         let offset = self.offsets[location.row() - 1] + location.column() - 1;
         &self.content[offset..]
     }
+
+    pub fn slice_source_code_range(&mut self, range: &Range) -> &'a str {
+        if !self.initialized {
+            let mut offset = 0;
+            for i in self.content.lines() {
+                self.offsets.push(offset);
+                offset += i.len();
+                offset += 1;
+            }
+            self.initialized = true;
+        }
+        let start = self.offsets[range.location.row() - 1] + range.location.column() - 1;
+        let end = self.offsets[range.end_location.row() - 1] + range.end_location.column() - 1;
+        &self.content[start..end]
+    }
 }

src/ast/relocate.rs

@@ -1,13 +1,17 @@
-use rustpython_parser::ast::{Expr, ExprKind, Keyword, Location};
+use rustpython_parser::ast::{Expr, ExprKind, Keyword};
 
-fn relocate_keyword(keyword: &mut Keyword, location: Location) {
-    keyword.location = location;
+use crate::ast::types::Range;
+
+fn relocate_keyword(keyword: &mut Keyword, location: Range) {
+    keyword.location = location.location;
+    keyword.end_location = location.end_location;
     relocate_expr(&mut keyword.node.value, location);
 }
 
 /// Change an expression's location (recursively) to match a desired, fixed location.
-pub fn relocate_expr(expr: &mut Expr, location: Location) {
-    expr.location = location;
+pub fn relocate_expr(expr: &mut Expr, location: Range) {
+    expr.location = location.location;
+    expr.end_location = location.end_location;
     match &mut expr.node {
         ExprKind::BoolOp { values, .. } => {
             for expr in values {

src/ast/types.rs

@@ -1,17 +1,37 @@
 use std::collections::BTreeMap;
 use std::sync::atomic::{AtomicUsize, Ordering};
 
-use rustpython_parser::ast::Location;
+use rustpython_parser::ast::{Located, Location};
 
 fn id() -> usize {
     static COUNTER: AtomicUsize = AtomicUsize::new(1);
     COUNTER.fetch_add(1, Ordering::Relaxed)
 }
 
+#[derive(Clone, Copy, Debug, Default, PartialEq, Eq, PartialOrd, Ord)]
+pub struct Range {
+    pub location: Location,
+    pub end_location: Location,
+}
+
+impl Range {
+    pub fn from_located<T>(located: &Located<T>) -> Self {
+        Range {
+            location: located.location,
+            end_location: located.end_location,
+        }
+    }
+}
+
+#[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 +40,7 @@ pub enum ScopeKind {
 pub struct Scope {
     pub id: usize,
     pub kind: ScopeKind,
+    pub import_starred: bool,
     pub values: BTreeMap<String, Binding>,
 }
 
@@ -28,28 +49,51 @@ impl Scope {
         Scope {
             id: id(),
             kind,
+            import_starred: false,
             values: BTreeMap::new(),
         }
     }
 }
 
+#[derive(Clone, Debug)]
+pub struct BindingContext {
+    pub defined_by: usize,
+    pub defined_in: Option<usize>,
+}
+
 #[derive(Clone, Debug)]
 pub enum BindingKind {
+    Annotation,
     Argument,
     Assignment,
+    Binding,
+    LoopVar,
     Builtin,
     ClassDefinition,
     Definition,
     Export(Vec<String>),
     FutureImportation,
-    Importation(String),
     StarImportation,
-    SubmoduleImportation(String),
+    Importation(String, BindingContext),
+    FromImportation(String, BindingContext),
+    SubmoduleImportation(String, BindingContext),
 }
 
 #[derive(Clone, Debug)]
 pub struct Binding {
     pub kind: BindingKind,
-    pub location: Location,
-    pub used: Option<usize>,
+    pub range: Range,
+    /// Tuple of (scope index, range) indicating the scope and range at which the binding was
+    /// last used.
+    pub used: Option<(usize, Range)>,
+}
+
+pub trait CheckLocator {
+    fn locate_check(&self, default: Range) -> Range;
+}
+
+#[derive(Clone, Copy, Debug, PartialEq, Eq, PartialOrd, Ord)]
+pub enum ImportKind {
+    Import,
+    ImportFrom,
 }

src/autofix/fixer.rs

@@ -2,6 +2,7 @@ use std::fs;
 use std::path::Path;
 
 use anyhow::Result;
+use itertools::Itertools;
 use rustpython_parser::ast::Location;
 
 use crate::checks::{Check, Fix};
@@ -43,41 +44,46 @@ fn apply_fixes<'a>(fixes: impl Iterator<Item = &'a mut Fix>, contents: &str) ->
     let mut output = "".to_string();
     let mut last_pos: Location = Location::new(0, 0);
 
-    for fix in fixes {
+    for fix in fixes.sorted_by_key(|fix| fix.location) {
         // Best-effort approach: if this fix overlaps with a fix we've already applied, skip it.
-        if last_pos > fix.start {
+        if last_pos > fix.location {
             continue;
         }
 
-        if fix.start.row() > last_pos.row() {
+        if fix.location.row() > last_pos.row() {
             if last_pos.row() > 0 || last_pos.column() > 0 {
                 output.push_str(&lines[last_pos.row() - 1][last_pos.column() - 1..]);
                 output.push('\n');
             }
-            for line in &lines[last_pos.row()..fix.start.row() - 1] {
+            for line in &lines[last_pos.row()..fix.location.row() - 1] {
                 output.push_str(line);
                 output.push('\n');
             }
-            output.push_str(&lines[fix.start.row() - 1][..fix.start.column() - 1]);
+            output.push_str(&lines[fix.location.row() - 1][..fix.location.column() - 1]);
             output.push_str(&fix.content);
         } else {
             output.push_str(
-                &lines[last_pos.row() - 1][last_pos.column() - 1..fix.start.column() - 1],
+                &lines[last_pos.row() - 1][last_pos.column() - 1..fix.location.column() - 1],
             );
             output.push_str(&fix.content);
         }
 
-        last_pos = fix.end;
+        last_pos = fix.end_location;
         fix.applied = true;
     }
 
-    if last_pos.row() > 0 || last_pos.column() > 0 {
+    if last_pos.row() > 0
+        && (last_pos.row() - 1) < lines.len()
+        && (last_pos.row() > 0 || last_pos.column() > 0)
+    {
         output.push_str(&lines[last_pos.row() - 1][last_pos.column() - 1..]);
         output.push('\n');
     }
-    for line in &lines[last_pos.row()..] {
-        output.push_str(line);
-        output.push('\n');
+    if last_pos.row() < lines.len() {
+        for line in &lines[last_pos.row()..] {
+            output.push_str(line);
+            output.push('\n');
+        }
     }
 
     output
@@ -106,8 +112,8 @@ mod tests {
     fn apply_single_replacement() -> Result<()> {
         let mut fixes = vec![Fix {
             content: "Bar".to_string(),
-            start: Location::new(1, 9),
-            end: Location::new(1, 15),
+            location: Location::new(1, 9),
+            end_location: Location::new(1, 15),
             applied: false,
         }];
         let actual = apply_fixes(
@@ -130,8 +136,8 @@ mod tests {
     fn apply_single_removal() -> Result<()> {
         let mut fixes = vec![Fix {
             content: "".to_string(),
-            start: Location::new(1, 8),
-            end: Location::new(1, 16),
+            location: Location::new(1, 8),
+            end_location: Location::new(1, 16),
             applied: false,
         }];
         let actual = apply_fixes(
@@ -155,14 +161,14 @@ mod tests {
         let mut fixes = vec![
             Fix {
                 content: "".to_string(),
-                start: Location::new(1, 8),
-                end: Location::new(1, 17),
+                location: Location::new(1, 8),
+                end_location: Location::new(1, 17),
                 applied: false,
             },
             Fix {
                 content: "".to_string(),
-                start: Location::new(1, 17),
-                end: Location::new(1, 24),
+                location: Location::new(1, 17),
+                end_location: Location::new(1, 24),
                 applied: false,
             },
         ];
@@ -187,14 +193,14 @@ mod tests {
         let mut fixes = vec![
             Fix {
                 content: "".to_string(),
-                start: Location::new(1, 8),
-                end: Location::new(1, 16),
+                location: Location::new(1, 8),
+                end_location: Location::new(1, 16),
                 applied: false,
             },
             Fix {
                 content: "ignored".to_string(),
-                start: Location::new(1, 10),
-                end: Location::new(1, 12),
+                location: Location::new(1, 10),
+                end_location: Location::new(1, 12),
                 applied: false,
             },
         ];

src/autofix/fixes.rs

@@ -1,8 +1,14 @@
-use rustpython_parser::ast::{Expr, Keyword, Location};
+use anyhow::Result;
+use itertools::Itertools;
+use libcst_native::ImportNames::Aliases;
+use libcst_native::NameOrAttribute::N;
+use libcst_native::{Codegen, Expression, SmallStatement, Statement};
+use rustpython_parser::ast::{ExcepthandlerKind, Expr, Keyword, Location, Stmt, StmtKind};
 use rustpython_parser::lexer;
 use rustpython_parser::token::Tok;
 
 use crate::ast::operations::SourceCodeLocator;
+use crate::ast::types::Range;
 use crate::checks::Fix;
 
 /// Convert a location within a file (relative to `base`) to an absolute position.
@@ -25,7 +31,7 @@ pub fn remove_class_def_base(
     bases: &[Expr],
     keywords: &[Keyword],
 ) -> Option<Fix> {
-    let content = locator.slice_source_code(stmt_at);
+    let content = locator.slice_source_code_at(stmt_at);
 
     // Case 1: `object` is the only base.
     if bases.len() == 1 && keywords.is_empty() {
@@ -52,8 +58,8 @@ pub fn remove_class_def_base(
         return match (fix_start, fix_end) {
             (Some(start), Some(end)) => Some(Fix {
                 content: "".to_string(),
-                start,
-                end,
+                location: start,
+                end_location: end,
                 applied: false,
             }),
             _ => None,
@@ -91,8 +97,8 @@ pub fn remove_class_def_base(
         match (fix_start, fix_end) {
             (Some(start), Some(end)) => Some(Fix {
                 content: "".to_string(),
-                start,
-                end,
+                location: start,
+                end_location: end,
                 applied: false,
             }),
             _ => None,
@@ -116,11 +122,271 @@ pub fn remove_class_def_base(
         match (fix_start, fix_end) {
             (Some(start), Some(end)) => Some(Fix {
                 content: "".to_string(),
-                start,
-                end,
+                location: start,
+                end_location: end,
                 applied: false,
             }),
             _ => None,
         }
     }
 }
+
+pub fn remove_super_arguments(locator: &mut SourceCodeLocator, expr: &Expr) -> Option<Fix> {
+    let range = Range::from_located(expr);
+    let contents = locator.slice_source_code_range(&range);
+
+    let mut tree = match libcst_native::parse_module(contents, None) {
+        Ok(m) => m,
+        Err(_) => return None,
+    };
+
+    if let Some(Statement::Simple(body)) = tree.body.first_mut() {
+        if let Some(SmallStatement::Expr(body)) = body.body.first_mut() {
+            if let Expression::Call(body) = &mut body.value {
+                body.args = vec![];
+                body.whitespace_before_args = Default::default();
+                body.whitespace_after_func = Default::default();
+
+                let mut state = Default::default();
+                tree.codegen(&mut state);
+
+                return Some(Fix {
+                    content: state.to_string(),
+                    location: range.location,
+                    end_location: range.end_location,
+                    applied: false,
+                });
+            }
+        }
+    }
+
+    None
+}
+
+/// Determine if a body contains only a single statement, taking into account deleted.
+fn has_single_child(body: &[Stmt], deleted: &[&Stmt]) -> bool {
+    body.iter().filter(|child| !deleted.contains(child)).count() == 1
+}
+
+/// Determine if a child is the only statement in its body.
+fn is_lone_child(child: &Stmt, parent: &Stmt, deleted: &[&Stmt]) -> Result<bool> {
+    match &parent.node {
+        StmtKind::FunctionDef { body, .. }
+        | StmtKind::AsyncFunctionDef { body, .. }
+        | StmtKind::ClassDef { body, .. }
+        | StmtKind::With { body, .. }
+        | StmtKind::AsyncWith { body, .. } => {
+            if body.iter().contains(child) {
+                Ok(has_single_child(body, deleted))
+            } else {
+                Err(anyhow::anyhow!("Unable to find child in parent body."))
+            }
+        }
+        StmtKind::For { body, orelse, .. }
+        | StmtKind::AsyncFor { body, orelse, .. }
+        | StmtKind::While { body, orelse, .. }
+        | StmtKind::If { body, orelse, .. } => {
+            if body.iter().contains(child) {
+                Ok(has_single_child(body, deleted))
+            } else if orelse.iter().contains(child) {
+                Ok(has_single_child(orelse, deleted))
+            } else {
+                Err(anyhow::anyhow!("Unable to find child in parent body."))
+            }
+        }
+        StmtKind::Try {
+            body,
+            handlers,
+            orelse,
+            finalbody,
+        } => {
+            if body.iter().contains(child) {
+                Ok(has_single_child(body, deleted))
+            } else if orelse.iter().contains(child) {
+                Ok(has_single_child(orelse, deleted))
+            } else if finalbody.iter().contains(child) {
+                Ok(has_single_child(finalbody, deleted))
+            } else if let Some(body) = handlers.iter().find_map(|handler| match &handler.node {
+                ExcepthandlerKind::ExceptHandler { body, .. } => {
+                    if body.iter().contains(child) {
+                        Some(body)
+                    } else {
+                        None
+                    }
+                }
+            }) {
+                Ok(has_single_child(body, deleted))
+            } else {
+                Err(anyhow::anyhow!("Unable to find child in parent body."))
+            }
+        }
+        _ => Err(anyhow::anyhow!("Unable to find child in parent body.")),
+    }
+}
+
+pub fn remove_stmt(stmt: &Stmt, parent: Option<&Stmt>, deleted: &[&Stmt]) -> Result<Fix> {
+    if parent
+        .map(|parent| is_lone_child(stmt, parent, deleted))
+        .map_or(Ok(None), |v| v.map(Some))?
+        .unwrap_or_default()
+    {
+        // If removing this node would lead to an invalid syntax tree, replace
+        // it with a `pass`.
+        Ok(Fix {
+            location: stmt.location,
+            end_location: stmt.end_location,
+            content: "pass".to_string(),
+            applied: false,
+        })
+    } else {
+        // Otherwise, nuke the entire line.
+        // TODO(charlie): This logic assumes that there are no multi-statement physical lines.
+        Ok(Fix {
+            location: Location::new(stmt.location.row(), 1),
+            end_location: Location::new(stmt.end_location.row() + 1, 1),
+            content: "".to_string(),
+            applied: false,
+        })
+    }
+}
+
+/// Generate a Fix to remove any unused imports from an `import` statement.
+pub fn remove_unused_imports(
+    locator: &mut SourceCodeLocator,
+    full_names: &[&str],
+    stmt: &Stmt,
+    parent: Option<&Stmt>,
+    deleted: &[&Stmt],
+) -> Result<Fix> {
+    let mut tree = match libcst_native::parse_module(
+        locator.slice_source_code_range(&Range::from_located(stmt)),
+        None,
+    ) {
+        Ok(m) => m,
+        Err(_) => return Err(anyhow::anyhow!("Failed to extract CST from source.")),
+    };
+
+    let body = if let Some(Statement::Simple(body)) = tree.body.first_mut() {
+        body
+    } else {
+        return Err(anyhow::anyhow!("Expected node to be: Statement::Simple."));
+    };
+    let body = if let Some(SmallStatement::Import(body)) = body.body.first_mut() {
+        body
+    } else {
+        return Err(anyhow::anyhow!(
+            "Expected node to be: SmallStatement::ImportFrom."
+        ));
+    };
+    let aliases = &mut body.names;
+
+    // Preserve the trailing comma (or not) from the last entry.
+    let trailing_comma = aliases.last().and_then(|alias| alias.comma.clone());
+
+    // Identify unused imports from within the `import from`.
+    let mut removable = vec![];
+    for (index, alias) in aliases.iter().enumerate() {
+        if let N(import_name) = &alias.name {
+            if full_names.contains(&import_name.value) {
+                removable.push(index);
+            }
+        }
+    }
+    // TODO(charlie): This is quadratic.
+    for index in removable.iter().rev() {
+        aliases.remove(*index);
+    }
+
+    if let Some(alias) = aliases.last_mut() {
+        alias.comma = trailing_comma;
+    }
+
+    if aliases.is_empty() {
+        remove_stmt(stmt, parent, deleted)
+    } else {
+        let mut state = Default::default();
+        tree.codegen(&mut state);
+
+        Ok(Fix {
+            content: state.to_string(),
+            location: stmt.location,
+            end_location: stmt.end_location,
+            applied: false,
+        })
+    }
+}
+
+/// Generate a Fix to remove any unused imports from an `import from` statement.
+pub fn remove_unused_import_froms(
+    locator: &mut SourceCodeLocator,
+    full_names: &[&str],
+    stmt: &Stmt,
+    parent: Option<&Stmt>,
+    deleted: &[&Stmt],
+) -> Result<Fix> {
+    let mut tree = match libcst_native::parse_module(
+        locator.slice_source_code_range(&Range::from_located(stmt)),
+        None,
+    ) {
+        Ok(m) => m,
+        Err(_) => return Err(anyhow::anyhow!("Failed to extract CST from source.")),
+    };
+
+    let body = if let Some(Statement::Simple(body)) = tree.body.first_mut() {
+        body
+    } else {
+        return Err(anyhow::anyhow!("Expected node to be: Statement::Simple."));
+    };
+    let body = if let Some(SmallStatement::ImportFrom(body)) = body.body.first_mut() {
+        body
+    } else {
+        return Err(anyhow::anyhow!(
+            "Expected node to be: SmallStatement::ImportFrom."
+        ));
+    };
+    let aliases = if let Aliases(aliases) = &mut body.names {
+        aliases
+    } else {
+        return Err(anyhow::anyhow!("Expected node to be: Aliases."));
+    };
+
+    // Preserve the trailing comma (or not) from the last entry.
+    let trailing_comma = aliases.last().and_then(|alias| alias.comma.clone());
+
+    // Identify unused imports from within the `import from`.
+    let mut removable = vec![];
+    for (index, alias) in aliases.iter().enumerate() {
+        if let N(name) = &alias.name {
+            let import_name = if let Some(N(module_name)) = &body.module {
+                format!("{}.{}", module_name.value, name.value)
+            } else {
+                name.value.to_string()
+            };
+            if full_names.contains(&import_name.as_str()) {
+                removable.push(index);
+            }
+        }
+    }
+    // TODO(charlie): This is quadratic.
+    for index in removable.iter().rev() {
+        aliases.remove(*index);
+    }
+
+    if let Some(alias) = aliases.last_mut() {
+        alias.comma = trailing_comma;
+    }
+
+    if aliases.is_empty() {
+        remove_stmt(stmt, parent, deleted)
+    } else {
+        let mut state = Default::default();
+        tree.codegen(&mut state);
+
+        Ok(Fix {
+            content: state.to_string(),
+            location: stmt.location,
+            end_location: stmt.end_location,
+            applied: false,
+        })
+    }
+}

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_lines.rs

@@ -1,11 +1,17 @@
+use std::collections::BTreeMap;
+
 use rustpython_parser::ast::Location;
 
-use crate::checks::{Check, CheckKind};
+use crate::ast::types::Range;
+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.
-fn should_enforce_line_length(line: &str, limit: usize) -> bool {
-    if line.len() > limit {
+fn should_enforce_line_length(line: &str, length: usize, limit: usize) -> bool {
+    if length > limit {
         let mut chunks = line.split_whitespace();
         if let (Some(first), Some(_)) = (chunks.next(), chunks.next()) {
             // Do not enforce the line length for commented lines with a single word
@@ -19,34 +25,244 @@ fn should_enforce_line_length(line: &str, limit: usize) -> bool {
     }
 }
 
-pub fn check_lines(checks: &mut Vec<Check>, contents: &str, settings: &Settings) {
-    let enforce_line_too_long = settings.select.contains(CheckKind::LineTooLong.code());
+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.enabled.contains(&CheckCode::E501);
+    let enforce_noqa = settings.enabled.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_ref());
+                        ignored.push(index)
+                    }
+                    (Directive::Codes(_, _, codes), matches) => {
+                        if codes.contains(&check.kind.code().as_ref()) {
+                            matches.push(check.kind.code().as_ref());
+                            ignored.push(index);
+                        }
+                    }
+                    (Directive::None, _) => {}
+                }
             }
         }
 
         // Enforce line length.
-        if enforce_line_too_long && should_enforce_line_length(line, settings.line_length) {
-            let check = Check::new(
-                CheckKind::LineTooLong,
-                Location::new(row + 1, settings.line_length + 1),
-            );
-            if !check.is_inline_ignored(line) {
-                line_checks.push(check);
+        if enforce_line_too_long {
+            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),
+                    Range {
+                        location: Location::new(lineno + 1, 1),
+                        end_location: Location::new(lineno + 1, line_length + 1),
+                    },
+                );
+
+                match noqa {
+                    (Directive::All(_, _), matches) => {
+                        matches.push(check.kind.code().as_ref());
+                    }
+                    (Directive::Codes(_, _, codes), matches) => {
+                        if codes.contains(&check.kind.code().as_ref()) {
+                            matches.push(check.kind.code().as_ref());
+                        } else {
+                            line_checks.push(check);
+                        }
+                    }
+                    (Directive::None, _) => line_checks.push(check),
+                }
             }
         }
     }
+
+    // Enforce newlines at end of files.
+    if settings.enabled.contains(&CheckCode::W292) && !contents.ends_with('\n') {
+        // Note: if `lines.last()` is `None`, then `contents` is empty (and so we don't want to
+        // raise W292 anyway).
+        if let Some(line) = lines.last() {
+            let lineno = lines.len() - 1;
+            let noqa_lineno = noqa_line_for
+                .get(lineno)
+                .map(|lineno| lineno - 1)
+                .unwrap_or(lineno);
+
+            let noqa = noqa_directives
+                .entry(noqa_lineno)
+                .or_insert_with(|| (noqa::extract_noqa_directive(lines[noqa_lineno]), vec![]));
+
+            let check = Check::new(
+                CheckKind::NoNewLineAtEndOfFile,
+                Range {
+                    location: Location::new(lines.len(), line.len() + 1),
+                    end_location: Location::new(lines.len(), line.len() + 1),
+                },
+            );
+
+            match noqa {
+                (Directive::All(_, _), matches) => {
+                    matches.push(check.kind.code().as_ref());
+                }
+                (Directive::Codes(_, _, codes), matches) => {
+                    if codes.contains(&check.kind.code().as_ref()) {
+                        matches.push(check.kind.code().as_ref());
+                    } 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(start, end) => {
+                    if matches.is_empty() {
+                        let mut check = Check::new(
+                            CheckKind::UnusedNOQA(None),
+                            Range {
+                                location: Location::new(row + 1, start + 1),
+                                end_location: Location::new(row + 1, end + 1),
+                            },
+                        );
+                        if matches!(autofix, fixer::Mode::Generate | fixer::Mode::Apply) {
+                            check.amend(Fix {
+                                content: "".to_string(),
+                                location: Location::new(row + 1, start + 1),
+                                end_location: Location::new(
+                                    row + 1,
+                                    lines[row].chars().count() + 1,
+                                ),
+                                applied: false,
+                            });
+                        }
+                        line_checks.push(check);
+                    }
+                }
+                Directive::Codes(start, end, 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(", "))),
+                            Range {
+                                location: Location::new(row + 1, start + 1),
+                                end_location: Location::new(row + 1, end + 1),
+                            },
+                        );
+                        if matches!(autofix, fixer::Mode::Generate | fixer::Mode::Apply) {
+                            if valid_codes.is_empty() {
+                                check.amend(Fix {
+                                    content: "".to_string(),
+                                    location: Location::new(row + 1, start + 1),
+                                    end_location: Location::new(
+                                        row + 1,
+                                        lines[row].chars().count() + 1,
+                                    ),
+                                    applied: false,
+                                });
+                            } else {
+                                check.amend(Fix {
+                                    content: format!("  # noqa: {}", valid_codes.join(", ")),
+                                    location: Location::new(row + 1, start + 1),
+                                    end_location: 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 crate::autofix::fixer;
+    use crate::checks::{Check, CheckCode};
+    use crate::settings;
+
+    use super::check_lines;
+
+    #[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![];
+            check_lines(
+                &mut checks,
+                line,
+                &noqa_line_for,
+                &settings::Settings {
+                    line_length,
+                    ..settings::Settings::for_rule(CheckCode::E501)
+                },
+                &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

@@ -1,148 +1,149 @@
-use std::str::FromStr;
-
-use anyhow::Result;
-use once_cell::sync::Lazy;
-use regex::Regex;
+use itertools::Itertools;
 use rustpython_parser::ast::Location;
 use serde::{Deserialize, Serialize};
+use strum_macros::{AsRefStr, EnumIter, EnumString};
 
-#[derive(Debug, PartialEq, Eq, Serialize, Deserialize, Hash, PartialOrd, Ord)]
+use crate::ast::checks::Primitive;
+use crate::ast::types::Range;
+
+pub const DEFAULT_CHECK_CODES: [CheckCode; 43] = [
+    // pycodestyle errors
+    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,
+    // pycodestyle warnings
+    CheckCode::W292,
+    // pyflakes
+    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,
+];
+
+#[derive(
+    AsRefStr,
+    EnumIter,
+    EnumString,
+    Debug,
+    PartialEq,
+    Eq,
+    Clone,
+    Serialize,
+    Deserialize,
+    Hash,
+    PartialOrd,
+    Ord,
+)]
 pub enum CheckCode {
+    // pycodestyle errors
     E402,
     E501,
     E711,
     E712,
     E713,
     E714,
+    E721,
+    E722,
     E731,
+    E741,
+    E742,
+    E743,
     E902,
+    E999,
+    // pycodestyle warnings
+    W292,
+    // pyflakes
     F401,
+    F402,
     F403,
+    F404,
+    F405,
+    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,
-}
-
-impl FromStr for CheckCode {
-    type Err = anyhow::Error;
-
-    fn from_str(s: &str) -> Result<Self> {
-        match s {
-            "E402" => Ok(CheckCode::E402),
-            "E501" => Ok(CheckCode::E501),
-            "E711" => Ok(CheckCode::E711),
-            "E712" => Ok(CheckCode::E712),
-            "E713" => Ok(CheckCode::E713),
-            "E714" => Ok(CheckCode::E714),
-            "E731" => Ok(CheckCode::E731),
-            "E902" => Ok(CheckCode::E902),
-            "F401" => Ok(CheckCode::F401),
-            "F403" => Ok(CheckCode::F403),
-            "F541" => Ok(CheckCode::F541),
-            "F601" => Ok(CheckCode::F601),
-            "F602" => Ok(CheckCode::F602),
-            "F621" => Ok(CheckCode::F621),
-            "F622" => Ok(CheckCode::F622),
-            "F631" => Ok(CheckCode::F631),
-            "F634" => Ok(CheckCode::F634),
-            "F704" => Ok(CheckCode::F704),
-            "F706" => Ok(CheckCode::F706),
-            "F707" => Ok(CheckCode::F707),
-            "F821" => Ok(CheckCode::F821),
-            "F822" => Ok(CheckCode::F822),
-            "F823" => Ok(CheckCode::F823),
-            "F831" => Ok(CheckCode::F831),
-            "F841" => Ok(CheckCode::F841),
-            "F901" => Ok(CheckCode::F901),
-            "R001" => Ok(CheckCode::R001),
-            "R002" => Ok(CheckCode::R002),
-            _ => Err(anyhow::anyhow!("Unknown check code: {s}")),
-        }
-    }
-}
-
-impl CheckCode {
-    pub fn as_str(&self) -> &str {
-        match self {
-            CheckCode::E402 => "E402",
-            CheckCode::E501 => "E501",
-            CheckCode::E711 => "E711",
-            CheckCode::E712 => "E712",
-            CheckCode::E713 => "E713",
-            CheckCode::E714 => "E714",
-            CheckCode::E731 => "E731",
-            CheckCode::E902 => "E902",
-            CheckCode::F401 => "F401",
-            CheckCode::F403 => "F403",
-            CheckCode::F541 => "F541",
-            CheckCode::F601 => "F601",
-            CheckCode::F602 => "F602",
-            CheckCode::F621 => "F621",
-            CheckCode::F622 => "F622",
-            CheckCode::F631 => "F631",
-            CheckCode::F634 => "F634",
-            CheckCode::F704 => "F704",
-            CheckCode::F706 => "F706",
-            CheckCode::F707 => "F707",
-            CheckCode::F821 => "F821",
-            CheckCode::F822 => "F822",
-            CheckCode::F823 => "F823",
-            CheckCode::F831 => "F831",
-            CheckCode::F841 => "F841",
-            CheckCode::F901 => "F901",
-            CheckCode::R001 => "R001",
-            CheckCode::R002 => "R002",
-        }
-    }
-
-    /// The source for the check (either the AST, or the physical lines).
-    pub fn lint_source(&self) -> &'static LintSource {
-        match self {
-            CheckCode::E402 => &LintSource::AST,
-            CheckCode::E501 => &LintSource::Lines,
-            CheckCode::E711 => &LintSource::AST,
-            CheckCode::E712 => &LintSource::AST,
-            CheckCode::E713 => &LintSource::AST,
-            CheckCode::E714 => &LintSource::AST,
-            CheckCode::E731 => &LintSource::AST,
-            CheckCode::E902 => &LintSource::FileSystem,
-            CheckCode::F401 => &LintSource::AST,
-            CheckCode::F403 => &LintSource::AST,
-            CheckCode::F541 => &LintSource::AST,
-            CheckCode::F601 => &LintSource::AST,
-            CheckCode::F602 => &LintSource::AST,
-            CheckCode::F621 => &LintSource::AST,
-            CheckCode::F622 => &LintSource::AST,
-            CheckCode::F631 => &LintSource::AST,
-            CheckCode::F634 => &LintSource::AST,
-            CheckCode::F704 => &LintSource::AST,
-            CheckCode::F706 => &LintSource::AST,
-            CheckCode::F707 => &LintSource::AST,
-            CheckCode::F821 => &LintSource::AST,
-            CheckCode::F822 => &LintSource::AST,
-            CheckCode::F823 => &LintSource::AST,
-            CheckCode::F831 => &LintSource::AST,
-            CheckCode::F841 => &LintSource::AST,
-            CheckCode::F901 => &LintSource::AST,
-            CheckCode::R001 => &LintSource::AST,
-            CheckCode::R002 => &LintSource::AST,
-        }
-    }
+    // flake8-builtins
+    A001,
+    A002,
+    A003,
+    // flake8-comprehensions
+    C400,
+    C401,
+    C402,
+    C403,
+    C404,
+    C405,
+    C406,
+    C408,
+    // flake8-super
+    SPR001,
+    // flake8-print
+    T201,
+    T203,
+    // pyupgrade
+    U001,
+    U002,
+    U003,
+    U004,
+    U005,
+    U006,
+    U007,
+    // Meta
+    M001,
 }
 
 #[allow(clippy::upper_case_acronyms)]
@@ -158,132 +159,322 @@ pub enum RejectedCmpop {
     NotEq,
 }
 
-#[derive(Debug, PartialEq, Eq, Serialize, Deserialize)]
+#[derive(AsRefStr, Debug, PartialEq, Eq, Serialize, Deserialize)]
 pub enum CheckKind {
+    // pycodestyle errors
+    AmbiguousClassName(String),
+    AmbiguousFunctionName(String),
+    AmbiguousVariableName(String),
     AssertTuple,
+    BreakOutsideLoop,
+    ContinueOutsideLoop,
     DefaultExceptNotLast,
     DoNotAssignLambda,
+    DoNotUseBareExcept,
     DuplicateArgumentName,
+    ExpressionsInStarAssignment,
     FStringMissingPlaceholders,
+    ForwardAnnotationSyntaxError(String),
+    FutureFeatureNotDefined(String),
     IOError(String),
     IfTuple,
-    ImportStarUsage,
-    LineTooLong,
+    ImportShadowedByLoopVar(String, usize),
+    ImportStarNotPermitted(String),
+    ImportStarUsage(String, Vec<String>),
+    ImportStarUsed(String),
+    InvalidPrintSyntax,
+    IsLiteral,
+    LateFutureImport,
+    LineTooLong(usize, usize),
     ModuleImportNotAtTopOfFile,
     MultiValueRepeatedKeyLiteral,
     MultiValueRepeatedKeyVariable(String),
-    NoAssertEquals,
     NoneComparison(RejectedCmpop),
     NotInTest,
     NotIsTest,
     RaiseNotImplemented,
     ReturnOutsideFunction,
-    TooManyExpressionsInStarredAssignment,
+    SyntaxError(String),
     TrueFalseComparison(bool, RejectedCmpop),
     TwoStarredExpressions,
+    TypeComparison,
     UndefinedExport(String),
     UndefinedLocal(String),
     UndefinedName(String),
-    UnusedImport(String),
+    UnusedImport(Vec<String>),
     UnusedVariable(String),
-    UselessObjectInheritance(String),
     YieldOutsideFunction,
+    // pycodestyle warnings
+    NoNewLineAtEndOfFile,
+    // flake8-builtin
+    BuiltinVariableShadowing(String),
+    BuiltinArgumentShadowing(String),
+    BuiltinAttributeShadowing(String),
+    // flakes8-comprehensions
+    UnnecessaryGeneratorList,
+    UnnecessaryGeneratorSet,
+    UnnecessaryGeneratorDict,
+    UnnecessaryListComprehensionSet,
+    UnnecessaryListComprehensionDict,
+    UnnecessaryLiteralSet(String),
+    UnnecessaryLiteralDict(String),
+    UnnecessaryCollectionCall(String),
+    // flake8-super
+    SuperCallWithParameters,
+    // flake8-print
+    PrintFound,
+    PPrintFound,
+    // pyupgrade
+    TypeOfPrimitive(Primitive),
+    UnnecessaryAbspath,
+    UselessMetaclassType,
+    NoAssertEquals,
+    UselessObjectInheritance(String),
+    UsePEP585Annotation(String),
+    UsePEP604Annotation,
+    // Meta
+    UnusedNOQA(Option<String>),
 }
 
-impl CheckKind {
-    /// The name of the check.
-    pub fn name(&self) -> &'static str {
+impl CheckCode {
+    /// The source for the check (either the AST, the filesystem, or the physical lines).
+    pub fn lint_source(&self) -> &'static LintSource {
         match self {
-            CheckKind::AssertTuple => "AssertTuple",
-            CheckKind::DefaultExceptNotLast => "DefaultExceptNotLast",
-            CheckKind::DuplicateArgumentName => "DuplicateArgumentName",
-            CheckKind::FStringMissingPlaceholders => "FStringMissingPlaceholders",
-            CheckKind::IOError(_) => "IOError",
-            CheckKind::IfTuple => "IfTuple",
-            CheckKind::ImportStarUsage => "ImportStarUsage",
-            CheckKind::LineTooLong => "LineTooLong",
-            CheckKind::DoNotAssignLambda => "DoNotAssignLambda",
-            CheckKind::ModuleImportNotAtTopOfFile => "ModuleImportNotAtTopOfFile",
-            CheckKind::MultiValueRepeatedKeyLiteral => "MultiValueRepeatedKeyLiteral",
-            CheckKind::MultiValueRepeatedKeyVariable(_) => "MultiValueRepeatedKeyVariable",
-            CheckKind::NoAssertEquals => "NoAssertEquals",
-            CheckKind::NoneComparison(_) => "NoneComparison",
-            CheckKind::NotInTest => "NotInTest",
-            CheckKind::NotIsTest => "NotIsTest",
-            CheckKind::RaiseNotImplemented => "RaiseNotImplemented",
-            CheckKind::ReturnOutsideFunction => "ReturnOutsideFunction",
-            CheckKind::TooManyExpressionsInStarredAssignment => {
-                "TooManyExpressionsInStarredAssignment"
-            }
-            CheckKind::TrueFalseComparison(_, _) => "TrueFalseComparison",
-            CheckKind::TwoStarredExpressions => "TwoStarredExpressions",
-            CheckKind::UndefinedExport(_) => "UndefinedExport",
-            CheckKind::UndefinedLocal(_) => "UndefinedLocal",
-            CheckKind::UndefinedName(_) => "UndefinedName",
-            CheckKind::UnusedImport(_) => "UnusedImport",
-            CheckKind::UnusedVariable(_) => "UnusedVariable",
-            CheckKind::UselessObjectInheritance(_) => "UselessObjectInheritance",
-            CheckKind::YieldOutsideFunction => "YieldOutsideFunction",
+            CheckCode::E501 | CheckCode::M001 => &LintSource::Lines,
+            CheckCode::E902 => &LintSource::FileSystem,
+            _ => &LintSource::AST,
         }
     }
 
+    /// A placeholder representation of the CheckKind for the check.
+    pub fn kind(&self) -> CheckKind {
+        match self {
+            // pycodestyle errors
+            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("IOError: `...`".to_string()),
+            CheckCode::E999 => CheckKind::SyntaxError("`...`".to_string()),
+            // pycodestyle warnings
+            CheckCode::W292 => CheckKind::NoNewLineAtEndOfFile,
+            // pyflakes
+            CheckCode::F401 => CheckKind::UnusedImport(vec!["...".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(), vec!["...".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::ExpressionsInStarAssignment,
+            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,
+            // flake8-builtins
+            CheckCode::A001 => CheckKind::BuiltinVariableShadowing("...".to_string()),
+            CheckCode::A002 => CheckKind::BuiltinArgumentShadowing("...".to_string()),
+            CheckCode::A003 => CheckKind::BuiltinAttributeShadowing("...".to_string()),
+            // flake8-comprehensions
+            CheckCode::C400 => CheckKind::UnnecessaryGeneratorList,
+            CheckCode::C401 => CheckKind::UnnecessaryGeneratorSet,
+            CheckCode::C402 => CheckKind::UnnecessaryGeneratorDict,
+            CheckCode::C403 => CheckKind::UnnecessaryListComprehensionSet,
+            CheckCode::C404 => CheckKind::UnnecessaryListComprehensionDict,
+            CheckCode::C405 => CheckKind::UnnecessaryLiteralSet("<list/tuple>".to_string()),
+            CheckCode::C406 => CheckKind::UnnecessaryLiteralDict("<list/tuple>".to_string()),
+            CheckCode::C408 => {
+                CheckKind::UnnecessaryCollectionCall("<dict/list/tuple>".to_string())
+            }
+            // flake8-super
+            CheckCode::SPR001 => CheckKind::SuperCallWithParameters,
+            // flake8-print
+            CheckCode::T201 => CheckKind::PrintFound,
+            CheckCode::T203 => CheckKind::PPrintFound,
+            // pyupgrade
+            CheckCode::U001 => CheckKind::UselessMetaclassType,
+            CheckCode::U002 => CheckKind::UnnecessaryAbspath,
+            CheckCode::U003 => CheckKind::TypeOfPrimitive(Primitive::Str),
+            CheckCode::U004 => CheckKind::UselessObjectInheritance("...".to_string()),
+            CheckCode::U005 => CheckKind::NoAssertEquals,
+            CheckCode::U006 => CheckKind::UsePEP585Annotation("List".to_string()),
+            CheckCode::U007 => CheckKind::UsePEP604Annotation,
+            // Meta
+            CheckCode::M001 => CheckKind::UnusedNOQA(None),
+        }
+    }
+}
+
+impl CheckKind {
     /// A four-letter shorthand code for the check.
     pub fn code(&self) -> &'static CheckCode {
         match self {
+            // pycodestyle errors
+            CheckKind::AmbiguousClassName(_) => &CheckCode::E742,
+            CheckKind::AmbiguousFunctionName(_) => &CheckCode::E743,
+            CheckKind::AmbiguousVariableName(_) => &CheckCode::E741,
             CheckKind::AssertTuple => &CheckCode::F631,
+            CheckKind::BreakOutsideLoop => &CheckCode::F701,
+            CheckKind::ContinueOutsideLoop => &CheckCode::F702,
             CheckKind::DefaultExceptNotLast => &CheckCode::F707,
+            CheckKind::DoNotAssignLambda => &CheckCode::E731,
+            CheckKind::DoNotUseBareExcept => &CheckCode::E722,
             CheckKind::DuplicateArgumentName => &CheckCode::F831,
             CheckKind::FStringMissingPlaceholders => &CheckCode::F541,
+            CheckKind::ForwardAnnotationSyntaxError(_) => &CheckCode::F722,
+            CheckKind::FutureFeatureNotDefined(_) => &CheckCode::F407,
             CheckKind::IOError(_) => &CheckCode::E902,
             CheckKind::IfTuple => &CheckCode::F634,
-            CheckKind::ImportStarUsage => &CheckCode::F403,
-            CheckKind::LineTooLong => &CheckCode::E501,
-            CheckKind::DoNotAssignLambda => &CheckCode::E731,
+            CheckKind::ImportShadowedByLoopVar(_, _) => &CheckCode::F402,
+            CheckKind::ImportStarNotPermitted(_) => &CheckCode::F406,
+            CheckKind::ImportStarUsage(_, _) => &CheckCode::F405,
+            CheckKind::ImportStarUsed(_) => &CheckCode::F403,
+            CheckKind::InvalidPrintSyntax => &CheckCode::F633,
+            CheckKind::IsLiteral => &CheckCode::F632,
+            CheckKind::LateFutureImport => &CheckCode::F404,
+            CheckKind::LineTooLong(_, _) => &CheckCode::E501,
             CheckKind::ModuleImportNotAtTopOfFile => &CheckCode::E402,
             CheckKind::MultiValueRepeatedKeyLiteral => &CheckCode::F601,
             CheckKind::MultiValueRepeatedKeyVariable(_) => &CheckCode::F602,
-            CheckKind::NoAssertEquals => &CheckCode::R002,
             CheckKind::NoneComparison(_) => &CheckCode::E711,
             CheckKind::NotInTest => &CheckCode::E713,
             CheckKind::NotIsTest => &CheckCode::E714,
             CheckKind::RaiseNotImplemented => &CheckCode::F901,
             CheckKind::ReturnOutsideFunction => &CheckCode::F706,
-            CheckKind::TooManyExpressionsInStarredAssignment => &CheckCode::F621,
+            CheckKind::SyntaxError(_) => &CheckCode::E999,
+            CheckKind::ExpressionsInStarAssignment => &CheckCode::F621,
             CheckKind::TrueFalseComparison(_, _) => &CheckCode::E712,
             CheckKind::TwoStarredExpressions => &CheckCode::F622,
+            CheckKind::TypeComparison => &CheckCode::E721,
             CheckKind::UndefinedExport(_) => &CheckCode::F822,
             CheckKind::UndefinedLocal(_) => &CheckCode::F823,
             CheckKind::UndefinedName(_) => &CheckCode::F821,
             CheckKind::UnusedImport(_) => &CheckCode::F401,
             CheckKind::UnusedVariable(_) => &CheckCode::F841,
-            CheckKind::UselessObjectInheritance(_) => &CheckCode::R001,
             CheckKind::YieldOutsideFunction => &CheckCode::F704,
+            // pycodestyle warnings
+            CheckKind::NoNewLineAtEndOfFile => &CheckCode::W292,
+            // flake8-builtins
+            CheckKind::BuiltinVariableShadowing(_) => &CheckCode::A001,
+            CheckKind::BuiltinArgumentShadowing(_) => &CheckCode::A002,
+            CheckKind::BuiltinAttributeShadowing(_) => &CheckCode::A003,
+            // flake8-comprehensions
+            CheckKind::UnnecessaryGeneratorList => &CheckCode::C400,
+            CheckKind::UnnecessaryGeneratorSet => &CheckCode::C401,
+            CheckKind::UnnecessaryGeneratorDict => &CheckCode::C402,
+            CheckKind::UnnecessaryListComprehensionSet => &CheckCode::C403,
+            CheckKind::UnnecessaryListComprehensionDict => &CheckCode::C404,
+            CheckKind::UnnecessaryLiteralSet(_) => &CheckCode::C405,
+            CheckKind::UnnecessaryLiteralDict(_) => &CheckCode::C406,
+            CheckKind::UnnecessaryCollectionCall(_) => &CheckCode::C408,
+            // flake8-super
+            CheckKind::SuperCallWithParameters => &CheckCode::SPR001,
+            // flake8-print
+            CheckKind::PrintFound => &CheckCode::T201,
+            CheckKind::PPrintFound => &CheckCode::T203,
+            // pyupgrade
+            CheckKind::TypeOfPrimitive(_) => &CheckCode::U003,
+            CheckKind::UnnecessaryAbspath => &CheckCode::U002,
+            CheckKind::UselessMetaclassType => &CheckCode::U001,
+            CheckKind::NoAssertEquals => &CheckCode::U005,
+            CheckKind::UsePEP585Annotation(_) => &CheckCode::U006,
+            CheckKind::UsePEP604Annotation => &CheckCode::U007,
+            CheckKind::UselessObjectInheritance(_) => &CheckCode::U004,
+            // Meta
+            CheckKind::UnusedNOQA(_) => &CheckCode::M001,
         }
     }
 
     /// The body text for the check.
     pub fn body(&self) -> String {
         match self {
+            // pycodestyle errors
+            CheckKind::AmbiguousClassName(name) => {
+                format!("Ambiguous class name: `{}`", name)
+            }
+            CheckKind::AmbiguousFunctionName(name) => {
+                format!("Ambiguous function name: `{}`", name)
+            }
+            CheckKind::AmbiguousVariableName(name) => {
+                format!("Ambiguous variable name: `{}`", name)
+            }
             CheckKind::AssertTuple => {
                 "Assert test is a non-empty tuple, which is always `True`".to_string()
             }
+            CheckKind::BreakOutsideLoop => "`break` outside loop".to_string(),
+            CheckKind::ContinueOutsideLoop => "`continue` not properly in loop".to_string(),
             CheckKind::DefaultExceptNotLast => {
-                "an `except:` block as not the last exception handler".to_string()
+                "An `except:` block as not the last exception handler".to_string()
             }
+            CheckKind::DoNotAssignLambda => {
+                "Do not assign a lambda expression, use a def".to_string()
+            }
+            CheckKind::DoNotUseBareExcept => "Do not use bare `except`".to_string(),
             CheckKind::DuplicateArgumentName => {
                 "Duplicate argument name in function definition".to_string()
             }
+            CheckKind::ForwardAnnotationSyntaxError(body) => {
+                format!("Syntax error in forward annotation: `{body}`")
+            }
             CheckKind::FStringMissingPlaceholders => {
                 "f-string without any placeholders".to_string()
             }
-            CheckKind::IOError(name) => {
-                format!("No such file or directory: `{name}`")
+            CheckKind::FutureFeatureNotDefined(name) => {
+                format!("Future feature `{name}` is not defined")
             }
+            CheckKind::IOError(message) => message.clone(),
             CheckKind::IfTuple => "If test is a tuple, which is always `True`".to_string(),
-            CheckKind::ImportStarUsage => "Unable to detect undefined names".to_string(),
-            CheckKind::LineTooLong => "Line too long".to_string(),
-            CheckKind::DoNotAssignLambda => {
-                "Do not assign a lambda expression, use a def".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::ImportStarUsed(name) => {
+                format!("`from {name} import *` used; unable to detect undefined names")
+            }
+            CheckKind::ImportStarUsage(name, sources) => {
+                let sources = sources
+                    .iter()
+                    .map(|source| format!("`{}`", source))
+                    .join(", ");
+                format!("`{name}` may be undefined, or defined from star imports: {sources}")
+            }
+            CheckKind::IsLiteral => "Use `==` and `!=` to compare constant literals".to_string(),
+            CheckKind::LateFutureImport => {
+                "`from __future__` imports must occur at the beginning of the file".to_string()
+            }
+            CheckKind::LineTooLong(length, limit) => {
+                format!("Line too long ({length} > {limit} characters)")
             }
             CheckKind::ModuleImportNotAtTopOfFile => {
                 "Module level import not at top of file".to_string()
@@ -294,9 +485,6 @@ impl CheckKind {
             CheckKind::MultiValueRepeatedKeyVariable(name) => {
                 format!("Dictionary key `{name}` repeated")
             }
-            CheckKind::NoAssertEquals => {
-                "`assertEquals` is deprecated, use `assertEqual` instead".to_string()
-            }
             CheckKind::NoneComparison(op) => match op {
                 RejectedCmpop::Eq => "Comparison to `None` should be `cond is None`".to_string(),
                 RejectedCmpop::NotEq => {
@@ -309,10 +497,11 @@ impl CheckKind {
                 "`raise NotImplemented` should be `raise NotImplementedError`".to_string()
             }
             CheckKind::ReturnOutsideFunction => {
-                "a `return` statement outside of a function/method".to_string()
+                "`return` statement outside of a function/method".to_string()
             }
-            CheckKind::TooManyExpressionsInStarredAssignment => {
-                "too many expressions in star-unpacking assignment".to_string()
+            CheckKind::SyntaxError(message) => format!("SyntaxError: {message}"),
+            CheckKind::ExpressionsInStarAssignment => {
+                "Too many expressions in star-unpacking assignment".to_string()
             }
             CheckKind::TrueFalseComparison(value, op) => match *value {
                 true => match op {
@@ -332,69 +521,126 @@ impl CheckKind {
                     }
                 },
             },
-            CheckKind::TwoStarredExpressions => "two starred expressions in assignment".to_string(),
+            CheckKind::TwoStarredExpressions => "Two starred expressions in assignment".to_string(),
+            CheckKind::TypeComparison => "Do not compare types, use `isinstance()`".to_string(),
             CheckKind::UndefinedExport(name) => {
                 format!("Undefined name `{name}` in `__all__`")
             }
-            CheckKind::UndefinedName(name) => {
-                format!("Undefined name `{name}`")
-            }
             CheckKind::UndefinedLocal(name) => {
                 format!("Local variable `{name}` referenced before assignment")
             }
-            CheckKind::UnusedImport(name) => format!("`{name}` imported but unused"),
+            CheckKind::UndefinedName(name) => {
+                format!("Undefined name `{name}`")
+            }
+            CheckKind::UnusedImport(names) => {
+                let names = names.iter().map(|name| format!("`{name}`")).join(", ");
+                format!("{names} imported but unused")
+            }
             CheckKind::UnusedVariable(name) => {
                 format!("Local variable `{name}` is assigned to but never used")
             }
+            CheckKind::YieldOutsideFunction => {
+                "`yield` or `yield from` statement outside of a function/method".to_string()
+            }
+            // pycodestyle warnings
+            CheckKind::NoNewLineAtEndOfFile => "No newline at end of file".to_string(),
+            // flake8-builtins
+            CheckKind::BuiltinVariableShadowing(name) => {
+                format!("Variable `{name}` is shadowing a python builtin")
+            }
+            CheckKind::BuiltinArgumentShadowing(name) => {
+                format!("Argument `{name}` is shadowing a python builtin")
+            }
+            CheckKind::BuiltinAttributeShadowing(name) => {
+                format!("Class attribute `{name}` is shadowing a python builtin")
+            }
+            // flake8-comprehensions
+            CheckKind::UnnecessaryGeneratorList => {
+                "Unnecessary generator - rewrite as a list comprehension".to_string()
+            }
+            CheckKind::UnnecessaryGeneratorSet => {
+                "Unnecessary generator - rewrite as a set comprehension".to_string()
+            }
+            CheckKind::UnnecessaryGeneratorDict => {
+                "Unnecessary generator - rewrite as a dict comprehension".to_string()
+            }
+            CheckKind::UnnecessaryListComprehensionSet => {
+                "Unnecessary list comprehension - rewrite as a set comprehension".to_string()
+            }
+            CheckKind::UnnecessaryListComprehensionDict => {
+                "Unnecessary list comprehension - rewrite as a dict comprehension".to_string()
+            }
+            CheckKind::UnnecessaryLiteralSet(obj_type) => {
+                format!("Unnecessary {obj_type} literal - rewrite as a set literal")
+            }
+            CheckKind::UnnecessaryLiteralDict(obj_type) => {
+                format!("Unnecessary {obj_type} literal - rewrite as a dict literal")
+            }
+            CheckKind::UnnecessaryCollectionCall(obj_type) => {
+                format!("Unnecessary {obj_type} call - rewrite as a literal")
+            }
+            // flake8-super
+            CheckKind::SuperCallWithParameters => {
+                "Use `super()` instead of `super(__class__, self)`".to_string()
+            }
+            // flake8-print
+            CheckKind::PrintFound => "`print` found".to_string(),
+            CheckKind::PPrintFound => "`pprint` found".to_string(),
+            // pyupgrade
+            CheckKind::TypeOfPrimitive(primitive) => {
+                format!("Use `{}` instead of `type(...)`", primitive.builtin())
+            }
+            CheckKind::UnnecessaryAbspath => {
+                "`abspath(__file__)` is unnecessary in Python 3.9 and later".to_string()
+            }
+            CheckKind::UselessMetaclassType => "`__metaclass__ = type` is implied".to_string(),
+            CheckKind::NoAssertEquals => {
+                "`assertEquals` is deprecated, use `assertEqual` instead".to_string()
+            }
             CheckKind::UselessObjectInheritance(name) => {
                 format!("Class `{name}` inherits from object")
             }
-            CheckKind::YieldOutsideFunction => {
-                "a `yield` or `yield from` statement outside of a function/method".to_string()
+            CheckKind::UsePEP585Annotation(name) => {
+                format!(
+                    "Use `{}` instead of `{}` for type annotations",
+                    name.to_lowercase(),
+                    name,
+                )
             }
+            CheckKind::UsePEP604Annotation => "Use `X | Y` for type annotations".to_string(),
+            // Meta
+            CheckKind::UnusedNOQA(code) => match code {
+                None => "Unused `noqa` directive".to_string(),
+                Some(code) => format!("Unused `noqa` directive for: {code}"),
+            },
         }
     }
 
     /// Whether the check kind is (potentially) fixable.
     pub fn fixable(&self) -> bool {
-        match self {
-            CheckKind::AssertTuple => false,
-            CheckKind::DefaultExceptNotLast => false,
-            CheckKind::DuplicateArgumentName => false,
-            CheckKind::FStringMissingPlaceholders => false,
-            CheckKind::IOError(_) => false,
-            CheckKind::IfTuple => false,
-            CheckKind::ImportStarUsage => false,
-            CheckKind::DoNotAssignLambda => false,
-            CheckKind::LineTooLong => false,
-            CheckKind::ModuleImportNotAtTopOfFile => false,
-            CheckKind::MultiValueRepeatedKeyLiteral => false,
-            CheckKind::MultiValueRepeatedKeyVariable(_) => false,
-            CheckKind::NoAssertEquals => true,
-            CheckKind::NotInTest => false,
-            CheckKind::NotIsTest => false,
-            CheckKind::NoneComparison(_) => false,
-            CheckKind::RaiseNotImplemented => false,
-            CheckKind::ReturnOutsideFunction => false,
-            CheckKind::TooManyExpressionsInStarredAssignment => false,
-            CheckKind::TrueFalseComparison(_, _) => false,
-            CheckKind::TwoStarredExpressions => false,
-            CheckKind::UndefinedExport(_) => false,
-            CheckKind::UndefinedLocal(_) => false,
-            CheckKind::UndefinedName(_) => false,
-            CheckKind::UnusedImport(_) => false,
-            CheckKind::UnusedVariable(_) => false,
-            CheckKind::UselessObjectInheritance(_) => true,
-            CheckKind::YieldOutsideFunction => false,
-        }
+        matches!(
+            self,
+            CheckKind::NoAssertEquals
+                | CheckKind::PPrintFound
+                | CheckKind::PrintFound
+                | CheckKind::SuperCallWithParameters
+                | CheckKind::TypeOfPrimitive(_)
+                | CheckKind::UnnecessaryAbspath
+                | CheckKind::UnusedImport(_)
+                | CheckKind::UnusedNOQA(_)
+                | CheckKind::UselessMetaclassType
+                | CheckKind::UselessObjectInheritance(_)
+                | CheckKind::UsePEP585Annotation(_)
+                | CheckKind::UsePEP604Annotation
+        )
     }
 }
 
 #[derive(Debug, PartialEq, Eq, Serialize, Deserialize)]
 pub struct Fix {
     pub content: String,
-    pub start: Location,
-    pub end: Location,
+    pub location: Location,
+    pub end_location: Location,
     pub applied: bool,
 }
 
@@ -402,19 +648,16 @@ pub struct Fix {
 pub struct Check {
     pub kind: CheckKind,
     pub location: Location,
+    pub end_location: Location,
     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 {
+    pub fn new(kind: CheckKind, span: Range) -> Self {
         Self {
             kind,
-            location,
+            location: span.location,
+            end_location: span.end_location,
             fix: None,
         }
     }
@@ -422,25 +665,26 @@ 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,
+#[cfg(test)]
+mod tests {
+    use std::str::FromStr;
+
+    use anyhow::Result;
+    use strum::IntoEnumIterator;
+
+    use crate::checks::CheckCode;
+
+    #[test]
+    fn check_code_serialization() -> Result<()> {
+        for check_code in CheckCode::iter() {
+            assert!(
+                CheckCode::from_str(check_code.as_ref()).is_ok(),
+                "{:?} could not be round-trip serialized.",
+                check_code
+            );
         }
+        Ok(())
     }
 }

src/cli.rs

@@ -0,0 +1,136 @@
+use std::fmt;
+use std::path::PathBuf;
+
+use clap::{command, Parser};
+use log::warn;
+use regex::Regex;
+
+use crate::checks::CheckCode;
+use crate::printer::SerializationFormat;
+use crate::pyproject::StrCheckCodePair;
+use crate::settings::PythonVersion;
+use crate::RawSettings;
+
+#[derive(Debug, Parser)]
+#[command(author, about = "ruff: An extremely fast Python linter.")]
+#[command(version)]
+pub struct Cli {
+    #[arg(required = true)]
+    pub files: Vec<PathBuf>,
+    /// Enable verbose logging.
+    #[arg(short, long)]
+    pub verbose: bool,
+    /// Disable all logging (but still exit with status code "1" upon detecting errors).
+    #[arg(short, long)]
+    pub quiet: bool,
+    /// Exit with status code "0", even upon detecting errors.
+    #[arg(short, long)]
+    pub exit_zero: bool,
+    /// Run in watch mode by re-running whenever files change.
+    #[arg(short, long)]
+    pub watch: bool,
+    /// Attempt to automatically fix lint errors.
+    #[arg(short, long)]
+    pub fix: bool,
+    /// Disable cache reads.
+    #[arg(short, long)]
+    pub no_cache: bool,
+    /// List of error codes to enable.
+    #[arg(long, value_delimiter = ',')]
+    pub select: Vec<CheckCode>,
+    /// Like --select, but adds additional error codes on top of the selected ones.
+    #[arg(long, value_delimiter = ',')]
+    pub extend_select: Vec<CheckCode>,
+    /// List of error codes to ignore.
+    #[arg(long, value_delimiter = ',')]
+    pub ignore: Vec<CheckCode>,
+    /// Like --ignore, but adds additional error codes on top of the ignored ones.
+    #[arg(long, value_delimiter = ',')]
+    pub extend_ignore: Vec<CheckCode>,
+    /// List of paths, used to exclude files and/or directories from checks.
+    #[arg(long, value_delimiter = ',')]
+    pub exclude: Vec<String>,
+    /// Like --exclude, but adds additional files and directories on top of the excluded ones.
+    #[arg(long, value_delimiter = ',')]
+    pub extend_exclude: Vec<String>,
+    /// List of mappings from file pattern to code to exclude
+    #[arg(long, value_delimiter = ',')]
+    pub per_file_ignores: Vec<StrCheckCodePair>,
+    /// Output serialization format for error messages.
+    #[arg(long, value_enum, default_value_t=SerializationFormat::Text)]
+    pub format: SerializationFormat,
+    /// See the files ruff will be run against with the current settings.
+    #[arg(long)]
+    pub show_files: bool,
+    /// See ruff's settings.
+    #[arg(long)]
+    pub show_settings: bool,
+    /// Enable automatic additions of noqa directives to failing lines.
+    #[arg(long)]
+    pub add_noqa: bool,
+    /// Regular expression matching the name of dummy variables.
+    #[arg(long)]
+    pub dummy_variable_rgx: Option<Regex>,
+    /// The minimum Python version that should be supported.
+    #[arg(long)]
+    pub target_version: Option<PythonVersion>,
+    /// Round-trip auto-formatting.
+    // TODO(charlie): This should be a sub-command.
+    #[arg(long, hide = true)]
+    pub autoformat: bool,
+}
+
+pub enum Warnable {
+    Select,
+    ExtendSelect,
+}
+
+impl fmt::Display for Warnable {
+    fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
+        match self {
+            Warnable::Select => fmt.write_str("--select"),
+            Warnable::ExtendSelect => fmt.write_str("--extend-select"),
+        }
+    }
+}
+
+/// Warn the user if they attempt to enable a code that won't be respected.
+pub fn warn_on(
+    flag: Warnable,
+    codes: &Vec<CheckCode>,
+    cli_ignore: &Vec<CheckCode>,
+    cli_extend_ignore: &Vec<CheckCode>,
+    pyproject_settings: &RawSettings,
+    pyproject_path: &Option<PathBuf>,
+) {
+    for code in codes {
+        if !cli_ignore.is_empty() {
+            if cli_ignore.contains(code) {
+                warn!("{code:?} was passed to {flag}, but ignored via --ignore")
+            }
+        } else if pyproject_settings.ignore.contains(code) {
+            if let Some(path) = pyproject_path {
+                warn!(
+                    "{code:?} was passed to {flag}, but ignored by the `ignore` field in {}",
+                    path.to_string_lossy()
+                )
+            } else {
+                warn!("{code:?} was passed to {flag}, but ignored by the default `ignore` field",)
+            }
+        }
+        if !cli_extend_ignore.is_empty() {
+            if cli_extend_ignore.contains(code) {
+                warn!("{code:?} was passed to {flag}, but ignored via --extend-ignore")
+            }
+        } else if pyproject_settings.extend_ignore.contains(code) {
+            if let Some(path) = pyproject_path {
+                warn!(
+                    "{code:?} was passed to {flag}, but ignored by the `extend_ignore` field in {}",
+                    path.to_string_lossy()
+                )
+            } else {
+                warn!("{code:?} was passed to {flag}, but ignored by the default `extend_ignore` field")
+            }
+        }
+    }
+}

src/fs.rs

@@ -1,39 +1,167 @@
+use std::borrow::Cow;
+use std::collections::BTreeSet;
 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_not_hidden(entry: &DirEntry) -> bool {
-    entry
-        .file_name()
+use crate::checks::CheckCode;
+use crate::settings::{FilePattern, PerFileIgnore};
+
+/// 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()
-        .map(|s| (entry.depth() == 0 || !s.starts_with('.')))
-        .unwrap_or(false)
+        .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_not_excluded(entry: &DirEntry, exclude: &[Pattern]) -> bool {
-    entry
-        .path()
-        .to_str()
-        .map(|s| !exclude.iter().any(|pattern| pattern.matches(s)))
-        .unwrap_or(false)
+fn is_excluded<'a, T>(file_path: &str, file_basename: &str, exclude: T) -> bool
+where
+    T: Iterator<Item = &'a FilePattern>,
+{
+    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
+}
+
+fn is_included(path: &Path) -> bool {
+    let file_name = path.to_string_lossy();
+    file_name.ends_with(".py") || file_name.ends_with(".pyi")
 }
 
 pub fn iter_python_files<'a>(
-    path: &'a PathBuf,
-    exclude: &'a [Pattern],
-) -> impl Iterator<Item = DirEntry> + 'a {
-    WalkDir::new(path)
-        .follow_links(true)
+    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))
         .into_iter()
-        .filter_entry(|entry| is_not_hidden(entry) && is_not_excluded(entry, exclude))
-        .filter_map(|entry| entry.ok())
-        .filter(|entry| entry.path().to_string_lossy().ends_with(".py"))
+        .filter_entry(move |entry| {
+            if !has_exclude && !has_extend_exclude {
+                return true;
+            }
+
+            let path = entry.path();
+            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.iter())
+                    {
+                        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.iter())
+                    {
+                        debug!("Ignored path via `extend-exclude`: {:?}", path);
+                        false
+                    } else {
+                        true
+                    }
+                }
+                Err(_) => {
+                    debug!("Ignored path due to error in parsing: {:?}", path);
+                    true
+                }
+            }
+        })
+        .filter(|entry| {
+            entry.as_ref().map_or(true, |entry| {
+                (entry.depth() == 0 || is_included(entry.path()))
+                    && !entry.file_type().is_dir()
+                    && !(entry.file_type().is_symlink() && entry.path().is_dir())
+            })
+        })
 }
 
+/// Create tree set with codes matching the pattern/code pairs.
+pub fn ignores_from_path<'a>(
+    path: &Path,
+    pattern_code_pairs: &'a [PerFileIgnore],
+) -> Result<BTreeSet<&'a CheckCode>> {
+    let (file_path, file_basename) = extract_path_names(path)?;
+    Ok(pattern_code_pairs
+        .iter()
+        .filter(|pattern_code_pair| {
+            is_excluded(
+                file_path,
+                file_basename,
+                [&pattern_code_pair.pattern].into_iter(),
+            )
+        })
+        .map(|pattern_code_pair| &pattern_code_pair.code)
+        .collect())
+}
+
+/// 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);
@@ -41,3 +169,100 @@ pub fn read_file(path: &Path) -> Result<String> {
     buf_reader.read_to_string(&mut contents)?;
     Ok(contents)
 }
+
+#[cfg(test)]
+mod tests {
+    use std::path::Path;
+
+    use anyhow::Result;
+    use path_absolutize::Absolutize;
+
+    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").absolutize().unwrap();
+        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").absolutize().unwrap();
+        assert!(!is_included(&path));
+
+        let path = Path::new("foo/bar/baz").absolutize().unwrap();
+        assert!(!is_included(&path));
+    }
+
+    #[test]
+    fn exclusions() -> Result<()> {
+        let project_root = Path::new("/tmp/");
+
+        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.iter()));
+
+        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.iter()));
+
+        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.iter()));
+
+        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.iter()));
+
+        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.iter()));
+
+        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.iter()));
+
+        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.iter()));
+
+        Ok(())
+    }
+}

src/lib.rs

@@ -1,15 +1,76 @@
-extern crate core;
+use std::path::Path;
+
+use anyhow::Result;
+use log::debug;
+use rustpython_parser::lexer::LexResult;
+
+use crate::autofix::fixer::Mode;
+use crate::linter::{check_path, tokenize};
+use crate::message::Message;
+use crate::settings::{RawSettings, Settings};
 
 mod ast;
 mod autofix;
-mod cache;
+pub mod cache;
 pub mod check_ast;
 mod check_lines;
 pub mod checks;
+pub mod cli;
+pub mod code_gen;
 pub mod fs;
 pub mod linter;
 pub mod logging;
 pub mod message;
-mod pyproject;
+mod noqa;
+mod plugins;
+pub mod printer;
+pub mod pyproject;
 mod python;
 pub mod settings;
+
+/// Run ruff over Python source code directly.
+pub fn check(path: &Path, contents: &str) -> Result<Vec<Message>> {
+    // Find the project root and pyproject.toml.
+    let project_root = pyproject::find_project_root(&[path.to_path_buf()]);
+    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..."),
+    };
+
+    let settings = Settings::from_raw(RawSettings::from_pyproject(&pyproject, &project_root)?);
+
+    // Tokenize once.
+    let tokens: Vec<LexResult> = tokenize(contents);
+
+    // 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,
+        &noqa_line_for,
+        &settings,
+        &Mode::None,
+    )?;
+
+    // Convert to messages.
+    let messages: Vec<Message> = checks
+        .into_iter()
+        .map(|check| Message {
+            kind: check.kind,
+            fixed: check.fix.map(|fix| fix.applied).unwrap_or_default(),
+            location: check.location,
+            end_location: check.end_location,
+            filename: path.to_string_lossy().to_string(),
+        })
+        .collect();
+
+    Ok(messages)
+}

src/main.rs

@@ -1,60 +1,37 @@
+use std::io;
 use std::path::{Path, PathBuf};
 use std::process::ExitCode;
 use std::sync::mpsc::channel;
 use std::time::Instant;
 
 use anyhow::Result;
-use clap::{Parser, ValueHint};
+use clap::Parser;
 use colored::Colorize;
 use log::{debug, error};
 use notify::{raw_watcher, RecursiveMode, Watcher};
 use rayon::prelude::*;
 use walkdir::DirEntry;
 
-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::tell_user;
+use ruff::cache;
+use ruff::checks::CheckCode;
+use ruff::checks::CheckKind;
+use ruff::cli::{warn_on, Cli, Warnable};
+use ruff::fs::iter_python_files;
+use ruff::linter::add_noqa_to_path;
+use ruff::linter::autoformat_path;
+use ruff::linter::lint_path;
+use ruff::logging::set_up_logging;
+use ruff::message::Message;
+use ruff::printer::{Printer, SerializationFormat};
+use ruff::pyproject::{self};
+use ruff::settings::CurrentSettings;
+use ruff::settings::RawSettings;
+use ruff::settings::{FilePattern, PerFileIgnore, Settings};
+use ruff::tell_user;
 
 const CARGO_PKG_NAME: &str = env!("CARGO_PKG_NAME");
 const CARGO_PKG_VERSION: &str = env!("CARGO_PKG_VERSION");
 
-#[derive(Debug, Parser)]
-#[clap(name = format!("{CARGO_PKG_NAME} (v{CARGO_PKG_VERSION})"))]
-#[clap(about = "An extremely fast Python linter.", long_about = None)]
-struct Cli {
-    #[clap(parse(from_os_str), value_hint = ValueHint::AnyPath, required = true)]
-    files: Vec<PathBuf>,
-    /// Enable verbose logging.
-    #[clap(short, long, action)]
-    verbose: bool,
-    /// Disable all logging (but still exit with status code "1" upon detecting errors).
-    #[clap(short, long, action)]
-    quiet: bool,
-    /// Exit with status code "0", even upon detecting errors.
-    #[clap(short, long, action)]
-    exit_zero: bool,
-    /// Run in watch mode by re-running whenever files change.
-    #[clap(short, long, action)]
-    watch: bool,
-    /// Attempt to automatically fix lint errors.
-    #[clap(short, long, action)]
-    fix: bool,
-    /// Disable cache reads.
-    #[clap(short, long, action)]
-    no_cache: bool,
-    /// Comma-separated list of error codes to enable.
-    #[clap(long, multiple = true)]
-    select: Vec<CheckCode>,
-    /// Comma-separated list of error codes to ignore.
-    #[clap(long, multiple = true)]
-    ignore: Vec<CheckCode>,
-}
-
 #[cfg(feature = "update-informer")]
 fn check_for_updates() {
     use update_informer::{registry, Check};
@@ -79,6 +56,25 @@ fn check_for_updates() {
     }
 }
 
+fn show_settings(settings: RawSettings, project_root: Option<PathBuf>, pyproject: Option<PathBuf>) {
+    println!(
+        "{:#?}",
+        CurrentSettings::from_settings(settings, project_root, pyproject)
+    );
+}
+
+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,
@@ -87,9 +83,9 @@ 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))
+        .flat_map(|path| iter_python_files(path, &settings.exclude, &settings.extend_exclude))
         .collect();
     let duration = start.elapsed();
     debug!("Identified files to lint in: {:?}", duration);
@@ -98,27 +94,41 @@ 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| {
-                error!("Failed to check {}: {e:?}", entry.path().to_string_lossy());
-                vec![]
+            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.enabled.contains(&CheckCode::E902) {
+                        vec![Message {
+                            kind: CheckKind::IOError(message),
+                            fixed: false,
+                            location: Default::default(),
+                            end_location: Default::default(),
+                            filename: path.to_string_lossy().to_string(),
+                        }]
+                    } else {
+                        error!("Failed to check {}: {message}", path.to_string_lossy());
+                        vec![]
+                    }
+                } else {
+                    error!("{message}");
+                    vec![]
+                }
             })
         })
         .flatten()
         .collect();
 
-    if settings.select.contains(&CheckCode::E902) {
-        for file in files {
-            if !file.exists() {
-                messages.push(Message {
-                    kind: CheckKind::IOError(file.to_string_lossy().to_string()),
-                    fixed: false,
-                    location: Default::default(),
-                    filename: file.to_string_lossy().to_string(),
-                })
-            }
-        }
-    }
-
     messages.sort_unstable();
     let duration = start.elapsed();
     debug!("Checked files in: {:?}", duration);
@@ -126,52 +136,60 @@ 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(())
+    Ok(modifications)
 }
 
-fn report_continuously(messages: &[Message]) -> Result<()> {
-    tell_user!(
-        "Found {} error(s). Watching for file changes.",
-        messages.len(),
-    );
+fn autoformat(files: &[PathBuf], settings: &Settings) -> Result<usize> {
+    // Collect all the files to format.
+    let start = Instant::now();
+    let paths: Vec<DirEntry> = files
+        .iter()
+        .flat_map(|path| iter_python_files(path, &settings.exclude, &settings.extend_exclude))
+        .flatten()
+        .collect();
+    let duration = start.elapsed();
+    debug!("Identified files to lint in: {:?}", duration);
 
-    if !messages.is_empty() {
-        println!();
-        for message in messages {
-            println!("{}", message);
-        }
-    }
+    let start = Instant::now();
+    let modifications = paths
+        .par_iter()
+        .map(|entry| {
+            let path = entry.path();
+            autoformat_path(path)
+        })
+        .flatten()
+        .count();
 
-    Ok(())
+    let duration = start.elapsed();
+    debug!("Auto-formatted files in: {:?}", duration);
+
+    Ok(modifications)
 }
 
 fn inner_main() -> Result<ExitCode> {
@@ -179,28 +197,123 @@ fn inner_main() -> Result<ExitCode> {
 
     set_up_logging(cli.verbose)?;
 
-    // TODO(charlie): Can we avoid this cast?
-    let paths: Vec<&Path> = cli.files.iter().map(PathBuf::as_path).collect();
-    let mut settings = Settings::from_paths(paths)?;
+    // 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 per_file_ignores: Vec<PerFileIgnore> = cli
+        .per_file_ignores
+        .into_iter()
+        .map(|pair| PerFileIgnore::new(pair, &project_root))
+        .collect();
+
+    let mut settings = RawSettings::from_pyproject(&pyproject, &project_root)?;
+    if !exclude.is_empty() {
+        settings.exclude = exclude;
+    }
+    if !extend_exclude.is_empty() {
+        settings.extend_exclude = extend_exclude;
+    }
+    if !per_file_ignores.is_empty() {
+        settings.per_file_ignores = per_file_ignores;
+    }
     if !cli.select.is_empty() {
-        settings.select(cli.select);
+        warn_on(
+            Warnable::Select,
+            &cli.select,
+            &cli.ignore,
+            &cli.extend_ignore,
+            &settings,
+            &pyproject,
+        );
+        settings.select = cli.select;
+    }
+    if !cli.extend_select.is_empty() {
+        warn_on(
+            Warnable::ExtendSelect,
+            &cli.extend_select,
+            &cli.ignore,
+            &cli.extend_ignore,
+            &settings,
+            &pyproject,
+        );
+        settings.extend_select = cli.extend_select;
     }
     if !cli.ignore.is_empty() {
-        settings.ignore(&cli.ignore);
+        settings.ignore = cli.ignore;
+    }
+    if !cli.extend_ignore.is_empty() {
+        settings.extend_ignore = cli.extend_ignore;
+    }
+    if let Some(target_version) = cli.target_version {
+        settings.target_version = target_version;
+    }
+    if let Some(dummy_variable_rgx) = cli.dummy_variable_rgx {
+        settings.dummy_variable_rgx = dummy_variable_rgx;
     }
 
+    if cli.show_settings && cli.show_files {
+        eprintln!("Error: specify --show-settings or show-files (not both).");
+        return Ok(ExitCode::FAILURE);
+    }
+    if cli.show_settings {
+        show_settings(settings, project_root, pyproject);
+        return Ok(ExitCode::SUCCESS);
+    }
+
+    let settings = Settings::from_raw(settings);
+
+    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.")
+            eprintln!("Warning: --fix is not enabled in watch mode.");
+        }
+
+        if cli.add_noqa {
+            eprintln!("Warning: --no-qa is not enabled in watch mode.");
+        }
+
+        if cli.autoformat {
+            eprintln!("Warning: --autoformat is not enabled in watch mode.");
+        }
+
+        if cli.format != SerializationFormat::Text {
+            eprintln!("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.
@@ -215,12 +328,12 @@ 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)?;
                             }
                         }
                     }
@@ -228,16 +341,26 @@ 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 if cli.autoformat {
+        let modifications = autoformat(&cli.files, &settings)?;
+        if modifications > 0 {
+            println!("Formatted {modifications} files.");
+        }
     } 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")]
         check_for_updates();
 
-        if !messages.is_empty() && !cli.exit_zero {
+        if messages.iter().any(|message| !message.fixed) && !cli.exit_zero {
             return Ok(ExitCode::FAILURE);
         }
     }
@@ -248,6 +371,9 @@ fn inner_main() -> Result<ExitCode> {
 fn main() -> ExitCode {
     match inner_main() {
         Ok(code) => code,
-        Err(_) => ExitCode::FAILURE,
+        Err(err) => {
+            eprintln!("{} {:?}", "error".red().bold(), err);
+            ExitCode::FAILURE
+        }
     }
 }

src/message.rs

@@ -1,17 +1,20 @@
 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 {
     pub kind: CheckKind,
     pub fixed: bool,
     pub location: Location,
+    pub end_location: Location,
     pub filename: String,
 }
 
@@ -20,7 +23,7 @@ impl Ord for Message {
         (&self.filename, self.location.row(), self.location.column()).cmp(&(
             &other.filename,
             other.location.row(),
-            self.location.column(),
+            other.location.column(),
         ))
     }
 }
@@ -36,13 +39,13 @@ impl fmt::Display for Message {
         write!(
             f,
             "{}{}{}{}{}{} {} {}",
-            self.filename.white().bold(),
+            relativize_path(Path::new(&self.filename)).white().bold(),
             ":".cyan(),
             self.location.row(),
             ":".cyan(),
             self.location.column(),
             ":".cyan(),
-            self.kind.code().as_str().red().bold(),
+            self.kind.code().as_ref().red().bold(),
             self.kind.body()
         )
     }

src/noqa.rs

@@ -0,0 +1,309 @@
+use std::cmp::{max, min};
+use std::collections::{BTreeMap, BTreeSet};
+use std::fs;
+use std::path::Path;
+
+use anyhow::Result;
+use once_cell::sync::Lazy;
+use regex::Regex;
+use rustpython_parser::lexer::{LexResult, Tok};
+
+use crate::checks::{Check, CheckCode};
+
+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, usize),
+    Codes(usize, 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(),
+                    noqa.end(),
+                    SPLIT_COMMA_REGEX
+                        .split(codes.as_str())
+                        .map(|code| code.trim())
+                        .filter(|code| !code.is_empty())
+                        .collect(),
+                ),
+                None => Directive::All(noqa.start(), noqa.end()),
+            },
+            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 min_line = usize::MAX;
+    let mut max_line = usize::MIN;
+    let mut in_string = false;
+
+    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 in_string {
+                for i in (noqa_line_for.len())..(min_line - 1) {
+                    noqa_line_for.push(i + 1);
+                }
+                noqa_line_for.extend(vec![max_line; (max_line + 1) - min_line]);
+            }
+
+            min_line = usize::MAX;
+            max_line = usize::MIN;
+        } else {
+            min_line = min(min_line, start.row());
+            max_line = max(max_line, end.row());
+        }
+        in_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_default();
+            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_ref()).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 anyhow::Result;
+    use rustpython_parser::ast::Location;
+    use rustpython_parser::lexer;
+    use rustpython_parser::lexer::LexResult;
+
+    use crate::ast::types::Range;
+    use crate::checks::{Check, CheckKind};
+    use crate::noqa::{add_noqa_inner, extract_noqa_line_for};
+
+    #[test]
+    fn extraction() -> Result<()> {
+        let empty: Vec<usize> = Default::default();
+
+        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), empty);
+
+        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), empty);
+
+        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), empty);
+
+        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), empty);
+
+        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]);
+
+        let lxr: Vec<LexResult> = lexer::make_tokenizer(
+            "x = 1
+y = '''abc
+def
+ghi
+'''
+z = 2",
+        )
+        .collect();
+        assert_eq!(extract_noqa_line_for(&lxr), vec![1, 5, 5, 5, 5]);
+
+        let lxr: Vec<LexResult> = lexer::make_tokenizer(
+            "x = 1
+y = '''abc
+def
+ghi
+'''",
+        )
+        .collect();
+        assert_eq!(extract_noqa_line_for(&lxr), vec![1, 5, 5, 5, 5]);
+
+        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()),
+            Range {
+                location: Location::new(1, 1),
+                end_location: 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()),
+                Range {
+                    location: Location::new(1, 1),
+                    end_location: Location::new(1, 1),
+                },
+            ),
+            Check::new(
+                CheckKind::UnusedVariable("x".to_string()),
+                Range {
+                    location: Location::new(1, 1),
+                    end_location: 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()),
+                Range {
+                    location: Location::new(1, 1),
+                    end_location: Location::new(1, 1),
+                },
+            ),
+            Check::new(
+                CheckKind::UnusedVariable("x".to_string()),
+                Range {
+                    location: Location::new(1, 1),
+                    end_location: 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/plugins.rs

@@ -0,0 +1,25 @@
+pub use assert_equals::assert_equals;
+pub use assert_tuple::assert_tuple;
+pub use if_tuple::if_tuple;
+pub use invalid_print_syntax::invalid_print_syntax;
+pub use print_call::print_call;
+pub use super_call_with_parameters::super_call_with_parameters;
+pub use type_of_primitive::type_of_primitive;
+pub use unnecessary_abspath::unnecessary_abspath;
+pub use use_pep585_annotation::use_pep585_annotation;
+pub use use_pep604_annotation::use_pep604_annotation;
+pub use useless_metaclass_type::useless_metaclass_type;
+pub use useless_object_inheritance::useless_object_inheritance;
+
+mod assert_equals;
+mod assert_tuple;
+mod if_tuple;
+mod invalid_print_syntax;
+mod print_call;
+mod super_call_with_parameters;
+mod type_of_primitive;
+mod unnecessary_abspath;
+mod use_pep585_annotation;
+mod use_pep604_annotation;
+mod useless_metaclass_type;
+mod useless_object_inheritance;

src/plugins/assert_equals.rs

@@ -0,0 +1,23 @@
+use rustpython_ast::{Expr, Location};
+
+use crate::ast::checks;
+use crate::autofix::fixer;
+use crate::check_ast::Checker;
+use crate::checks::Fix;
+
+pub fn assert_equals(checker: &mut Checker, expr: &Expr) {
+    if let Some(mut check) = checks::check_assert_equals(expr) {
+        if matches!(checker.autofix, fixer::Mode::Generate | fixer::Mode::Apply) {
+            check.amend(Fix {
+                content: "assertEqual".to_string(),
+                location: Location::new(expr.location.row(), expr.location.column() + 1),
+                end_location: Location::new(
+                    expr.location.row(),
+                    expr.location.column() + 1 + "assertEquals".len(),
+                ),
+                applied: false,
+            });
+        }
+        checker.add_check(check);
+    }
+}

src/plugins/assert_tuple.rs

@@ -0,0 +1,13 @@
+use rustpython_ast::{Expr, Stmt};
+
+use crate::ast::checks;
+use crate::ast::types::{CheckLocator, Range};
+use crate::check_ast::Checker;
+
+pub fn assert_tuple(checker: &mut Checker, stmt: &Stmt, test: &Expr) {
+    if let Some(check) =
+        checks::check_assert_tuple(test, checker.locate_check(Range::from_located(stmt)))
+    {
+        checker.add_check(check);
+    }
+}

src/plugins/if_tuple.rs

@@ -0,0 +1,13 @@
+use rustpython_ast::{Expr, Stmt};
+
+use crate::ast::checks;
+use crate::ast::types::{CheckLocator, Range};
+use crate::check_ast::Checker;
+
+pub fn if_tuple(checker: &mut Checker, stmt: &Stmt, test: &Expr) {
+    if let Some(check) =
+        checks::check_if_tuple(test, checker.locate_check(Range::from_located(stmt)))
+    {
+        checker.add_check(check);
+    }
+}

src/plugins/invalid_print_syntax.rs

@@ -0,0 +1,23 @@
+use rustpython_ast::{Expr, ExprKind};
+
+use crate::ast::types::{Binding, BindingKind, Range};
+use crate::check_ast::Checker;
+use crate::checks::{Check, CheckKind};
+
+pub fn invalid_print_syntax(checker: &mut Checker, left: &Expr) {
+    if let ExprKind::Name { id, .. } = &left.node {
+        if id == "print" {
+            let scope = checker.current_scope();
+            if let Some(Binding {
+                kind: BindingKind::Builtin,
+                ..
+            }) = scope.values.get("print")
+            {
+                checker.add_check(Check::new(
+                    CheckKind::InvalidPrintSyntax,
+                    Range::from_located(left),
+                ));
+            }
+        }
+    }
+}

src/plugins/print_call.rs

@@ -0,0 +1,46 @@
+use log::error;
+use rustpython_ast::{Expr, Stmt, StmtKind};
+
+use crate::ast::checks;
+use crate::autofix::{fixer, fixes};
+use crate::check_ast::Checker;
+use crate::checks::CheckCode;
+
+pub fn print_call(checker: &mut Checker, expr: &Expr, func: &Expr) {
+    if let Some(mut check) = checks::check_print_call(
+        expr,
+        func,
+        checker.settings.enabled.contains(&CheckCode::T201),
+        checker.settings.enabled.contains(&CheckCode::T203),
+    ) {
+        if matches!(checker.autofix, fixer::Mode::Generate | fixer::Mode::Apply) {
+            let context = checker.binding_context();
+            if matches!(
+                checker.parents[context.defined_by].node,
+                StmtKind::Expr { .. }
+            ) {
+                let deleted: Vec<&Stmt> = checker
+                    .deletions
+                    .iter()
+                    .map(|index| checker.parents[*index])
+                    .collect();
+
+                match fixes::remove_stmt(
+                    checker.parents[context.defined_by],
+                    context.defined_in.map(|index| checker.parents[index]),
+                    &deleted,
+                ) {
+                    Ok(fix) => {
+                        if fix.content.is_empty() || fix.content == "pass" {
+                            checker.deletions.insert(context.defined_by);
+                        }
+                        check.amend(fix)
+                    }
+                    Err(e) => error!("Failed to fix unused imports: {}", e),
+                }
+            }
+        }
+
+        checker.add_check(check);
+    }
+}

src/plugins/super_call_with_parameters.rs

@@ -0,0 +1,31 @@
+use rustpython_ast::{Expr, Stmt};
+
+use crate::ast::checks;
+use crate::autofix::{fixer, fixes};
+use crate::check_ast::Checker;
+
+pub fn super_call_with_parameters(
+    checker: &mut Checker,
+    expr: &Expr,
+    func: &Expr,
+    args: &Vec<Expr>,
+) {
+    // Only bother going through the super check at all if we're in a `super` call.
+    // (We check this in `check_super_args` too, so this is just an optimization.)
+    if checks::is_super_call_with_arguments(func, args) {
+        let scope = checker.current_scope();
+        let parents: Vec<&Stmt> = checker
+            .parent_stack
+            .iter()
+            .map(|index| checker.parents[*index])
+            .collect();
+        if let Some(mut check) = checks::check_super_args(scope, &parents, expr, func, args) {
+            if matches!(checker.autofix, fixer::Mode::Generate | fixer::Mode::Apply) {
+                if let Some(fix) = fixes::remove_super_arguments(&mut checker.locator, expr) {
+                    check.amend(fix);
+                }
+            }
+            checker.add_check(check)
+        }
+    }
+}

src/plugins/type_of_primitive.rs

@@ -0,0 +1,25 @@
+use rustpython_ast::Expr;
+
+use crate::ast::checks;
+use crate::ast::types::{CheckLocator, Range};
+use crate::autofix::fixer;
+use crate::check_ast::Checker;
+use crate::checks::{CheckKind, Fix};
+
+pub fn type_of_primitive(checker: &mut Checker, expr: &Expr, func: &Expr, args: &Vec<Expr>) {
+    if let Some(mut check) =
+        checks::check_type_of_primitive(func, args, checker.locate_check(Range::from_located(expr)))
+    {
+        if matches!(checker.autofix, fixer::Mode::Generate | fixer::Mode::Apply) {
+            if let CheckKind::TypeOfPrimitive(primitive) = &check.kind {
+                check.amend(Fix {
+                    content: primitive.builtin(),
+                    location: expr.location,
+                    end_location: expr.end_location,
+                    applied: false,
+                });
+            }
+        }
+        checker.add_check(check);
+    }
+}

src/plugins/unnecessary_abspath.rs

@@ -0,0 +1,25 @@
+use rustpython_ast::Expr;
+
+use crate::ast::checks;
+use crate::ast::types::{CheckLocator, Range};
+use crate::autofix::fixer;
+use crate::check_ast::Checker;
+use crate::checks::Fix;
+
+pub fn unnecessary_abspath(checker: &mut Checker, expr: &Expr, func: &Expr, args: &Vec<Expr>) {
+    if let Some(mut check) = checks::check_unnecessary_abspath(
+        func,
+        args,
+        checker.locate_check(Range::from_located(expr)),
+    ) {
+        if matches!(checker.autofix, fixer::Mode::Generate | fixer::Mode::Apply) {
+            check.amend(Fix {
+                content: "__file__".to_string(),
+                location: expr.location,
+                end_location: expr.end_location,
+                applied: false,
+            });
+        }
+        checker.add_check(check);
+    }
+}

src/plugins/use_pep585_annotation.rs

@@ -0,0 +1,26 @@
+use rustpython_ast::Expr;
+
+use crate::ast::types::Range;
+use crate::autofix::fixer;
+use crate::check_ast::Checker;
+use crate::checks::{Check, CheckKind, Fix};
+use crate::python::typing;
+
+pub fn use_pep585_annotation(checker: &mut Checker, expr: &Expr, id: &str) {
+    // TODO(charlie): Verify that the builtin is imported from the `typing` module.
+    if typing::is_pep585_builtin(id) {
+        let mut check = Check::new(
+            CheckKind::UsePEP585Annotation(id.to_string()),
+            Range::from_located(expr),
+        );
+        if matches!(checker.autofix, fixer::Mode::Generate | fixer::Mode::Apply) {
+            check.amend(Fix {
+                content: id.to_lowercase(),
+                location: expr.location,
+                end_location: expr.end_location,
+                applied: false,
+            })
+        }
+        checker.add_check(check);
+    }
+}

src/plugins/use_pep604_annotation.rs

@@ -0,0 +1,100 @@
+use rustpython_ast::{Constant, Expr, ExprKind, Operator};
+
+use crate::ast::helpers::match_name_or_attr;
+use crate::ast::types::Range;
+use crate::autofix::fixer;
+use crate::check_ast::Checker;
+use crate::checks::{Check, CheckKind, Fix};
+use crate::code_gen::SourceGenerator;
+
+fn optional(expr: &Expr) -> Expr {
+    Expr::new(
+        Default::default(),
+        Default::default(),
+        ExprKind::BinOp {
+            left: Box::new(expr.clone()),
+            op: Operator::BitOr,
+            right: Box::new(Expr::new(
+                Default::default(),
+                Default::default(),
+                ExprKind::Constant {
+                    value: Constant::None,
+                    kind: None,
+                },
+            )),
+        },
+    )
+}
+
+fn union(elts: &[Expr]) -> Expr {
+    if elts.len() == 1 {
+        elts[0].clone()
+    } else {
+        Expr::new(
+            Default::default(),
+            Default::default(),
+            ExprKind::BinOp {
+                left: Box::new(union(&elts[..elts.len() - 1])),
+                op: Operator::BitOr,
+                right: Box::new(elts[elts.len() - 1].clone()),
+            },
+        )
+    }
+}
+
+pub fn use_pep604_annotation(checker: &mut Checker, expr: &Expr, value: &Expr, slice: &Expr) {
+    if match_name_or_attr(value, "Optional") {
+        let mut check = Check::new(CheckKind::UsePEP604Annotation, Range::from_located(expr));
+        if matches!(checker.autofix, fixer::Mode::Generate | fixer::Mode::Apply) {
+            let mut generator = SourceGenerator::new();
+            if let Ok(()) = generator.unparse_expr(&optional(slice), 0) {
+                if let Ok(content) = generator.generate() {
+                    check.amend(Fix {
+                        content,
+                        location: expr.location,
+                        end_location: expr.end_location,
+                        applied: false,
+                    })
+                }
+            }
+        }
+        checker.add_check(check);
+    } else if match_name_or_attr(value, "Union") {
+        let mut check = Check::new(CheckKind::UsePEP604Annotation, Range::from_located(expr));
+        if matches!(checker.autofix, fixer::Mode::Generate | fixer::Mode::Apply) {
+            match &slice.node {
+                ExprKind::Slice { .. } => {
+                    // Invalid type annotation.
+                }
+                ExprKind::Tuple { elts, .. } => {
+                    let mut generator = SourceGenerator::new();
+                    if let Ok(()) = generator.unparse_expr(&union(elts), 0) {
+                        if let Ok(content) = generator.generate() {
+                            check.amend(Fix {
+                                content,
+                                location: expr.location,
+                                end_location: expr.end_location,
+                                applied: false,
+                            })
+                        }
+                    }
+                }
+                _ => {
+                    // Single argument.
+                    let mut generator = SourceGenerator::new();
+                    if let Ok(()) = generator.unparse_expr(slice, 0) {
+                        if let Ok(content) = generator.generate() {
+                            check.amend(Fix {
+                                content,
+                                location: expr.location,
+                                end_location: expr.end_location,
+                                applied: false,
+                            });
+                        }
+                    }
+                }
+            }
+        }
+        checker.add_check(check);
+    }
+}