Bump version to 0.0.68

.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

.pre-commit-config.yaml

@@ -3,3 +3,8 @@ repos:
     rev: v0.0.40
     hooks:
       - id: lint
+
+  - repo: https://github.com/abravalheri/validate-pyproject
+    rev: v0.10.1
+    hooks:
+      - id: validate-pyproject

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 = "0.0.47"
+version = "0.0.68"
 edition = "2021"
 
 [lib]
@@ -19,19 +19,25 @@ dirs = { version = "4.0.0" }
 fern = { version = "0.6.1" }
 filetime = { version = "0.2.17" }
 glob = { version = "0.3.0" }
-itertools = { version = "0.10.3" }
+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 = "966a80597d626a9a47eaec78471164422d341453" }
+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"
+num-bigint = "0.4.3"
 
 [dev-dependencies]
 insta = { version = "1.19.1", features = ["yaml"] }

README.md

@@ -20,7 +20,7 @@ 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
 - ⚖️ [Near-complete parity](#Parity-with-Flake8) with the built-in Flake8 rule set
 
@@ -57,7 +57,7 @@ ruff also works with [pre-commit](https://pre-commit.com):
 ```yaml
 repos:
   - repo: https://github.com/charliermarsh/ruff-pre-commit
-    rev: v0.0.40
+    rev: v0.0.48
     hooks:
       - id: lint
 ```
@@ -130,6 +130,8 @@ Options:
           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
@@ -201,67 +203,152 @@ 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 plugins, (2) alongside
+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, 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.)
 
+ruff also implements some of the most popular Flake8 plugins natively, including:
+
+- [`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/) (11/16)
+- [`flake8-bugbear`](https://pypi.org/project/flake8-bugbear/) (3/32)
+- [`flake8-docstrings`](https://pypi.org/project/flake8-docstrings/) (6/47)
+- [`pyupgrade`](https://pypi.org/project/pyupgrade/) (partial)
+
 Beyond rule-set parity, ruff suffers from the following limitations vis-à-vis Flake8:
 
-1. Flake8 has a plugin architecture and supports writing custom lint rules.
-2. ruff does not yet support parenthesized context managers.
+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.
 
 ## Rules
 
-| 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 | ... |
-| E999 | SyntaxError | SyntaxError: ... |
-| 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 | 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` |
-| F632 | IsLiteral | use ==/!= 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 | 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 |
-| 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` |
-| R001 | UselessObjectInheritance | Class `...` inherits from object |
-| R002 | NoAssertEquals | `assertEquals` is deprecated, use `assertEqual` instead |
-| M001 | UnusedNOQA | Unused `noqa` directive |
+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 |  |  |
+| B011 | DoNotAssertFalse | Do not `assert False` (`python -O` removes these calls), raise `AssertionError()` |  | 🛠 |
+| B014 | DuplicateHandlerException | Exception handler with duplicate exception: `ValueError |  | 🛠 |
+| B025 | DuplicateTryBlockException | try-except block with duplicate exception `Exception` |  |  |
+| C400 | UnnecessaryGeneratorList | Unnecessary generator - rewrite as a list comprehension |  |  |
+| C401 | UnnecessaryGeneratorSet | Unnecessary generator - rewrite as a set comprehension |  |  |
+| C402 | UnnecessaryGeneratorDict | Unnecessary generator - rewrite as a dict comprehension |  |  |
+| C403 | UnnecessaryListComprehensionSet | Unnecessary list comprehension - rewrite as a set comprehension |  |  |
+| C404 | UnnecessaryListComprehensionDict | Unnecessary list comprehension - rewrite as a dict comprehension |  |  |
+| C405 | UnnecessaryLiteralSet | Unnecessary <list/tuple> literal - rewrite as a set literal |  |  |
+| C406 | UnnecessaryLiteralDict | Unnecessary <list/tuple> literal - rewrite as a dict literal |  |  |
+| C408 | UnnecessaryCollectionCall | Unnecessary <dict/list/tuple> call - rewrite as a literal |  |  |
+| C409 | UnnecessaryLiteralWithinTupleCall | Unnecessary <list/tuple> literal passed to tuple() - remove the outer call to tuple() |  |  |
+| C410 | UnnecessaryLiteralWithinListCall | Unnecessary <list/tuple> literal passed to list() - rewrite as a list literal |  |  |
+| C415 | UnnecessarySubscriptReversal | Unnecessary subscript reversal of iterable within <reversed/set/sorted>() |  |  |
+| 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 | DeprecatedUnittestAlias | `assertEquals` is deprecated, use `assertEqual` instead |  | 🛠 |
+| U006 | UsePEP585Annotation | Use `list` instead of `List` for type annotations |  | 🛠 |
+| U007 | UsePEP604Annotation | Use `X \| Y` for type annotations |  | 🛠 |
+| U008 | SuperCallWithParameters | Use `super()` instead of `super(__class__, self)` |  | 🛠 |
+| D200 | OneLinerDocstring | One-line docstring should fit on one line |  |  |
+| D205 | BlankLineAfterSummary | 1 blank line required between summary line and description |  |  |
+| D209 | NewLineAfterLastParagraph | Multi-line docstring closing quotes should be on a separate line |  |  |
+| D210 | NoSurroundingWhitespace | No whitespaces allowed surrounding docstring text |  |  |
+| D400 | DocstringEndsInNonPeriod | First line should end with a period |  |  |
+| D419 | EmptyDocstring | Docstring is empty |  |  |
+| 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
 
@@ -422,3 +509,8 @@ Summary
 ## 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

@@ -1,19 +1,26 @@
 /// Generate a Markdown-compatible table of supported lint rules.
-use ruff::checks::{CheckCode, ALL_CHECK_CODES};
+use strum::IntoEnumIterator;
+
+use ruff::checks::{CheckCode, DEFAULT_CHECK_CODES};
 
 fn main() {
-    let mut check_codes: Vec<CheckCode> = ALL_CHECK_CODES.to_vec();
-    check_codes.sort();
-
-    println!("| Code | Name | Message |");
-    println!("| ---- | ----- | ------- |");
-    for check_code in check_codes {
+    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().replace("|", r"\|"),
+            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(())
+}

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/B011.py

@@ -0,0 +1,10 @@
+"""
+Should emit:
+B011 - on line 8
+B011 - on line 10
+"""
+
+assert 1 != 2
+assert False
+assert 1 != 2, "message"
+assert False, "message"

resources/test/fixtures/B014.py

@@ -0,0 +1,76 @@
+"""
+Should emit:
+B014 - on lines 11, 17, 28, 42, 49, 56, and 74.
+"""
+
+import binascii
+import re
+
+try:
+    pass
+except (Exception, TypeError):
+    # TypeError is a subclass of Exception, so it doesn't add anything
+    pass
+
+try:
+    pass
+except (OSError, OSError) as err:
+    # Duplicate exception types are useless
+    pass
+
+
+class MyError(Exception):
+    pass
+
+
+try:
+    pass
+except (MyError, MyError):
+    # Detect duplicate non-builtin errors
+    pass
+
+
+try:
+    pass
+except (MyError, Exception) as e:
+    # Don't assume that we're all subclasses of Exception
+    pass
+
+
+try:
+    pass
+except (MyError, BaseException) as e:
+    # But we *can* assume that everything is a subclass of BaseException
+    pass
+
+
+try:
+    pass
+except (re.error, re.error):
+    # Duplicate exception types as attributes
+    pass
+
+
+try:
+    pass
+except (IOError, EnvironmentError, OSError):
+    # Detect if a primary exception and any its aliases are present.
+    #
+    # Since Python 3.3, IOError, EnvironmentError, WindowsError, mmap.error,
+    # socket.error and select.error are aliases of OSError. See PEP 3151 for
+    # more info.
+    pass
+
+
+try:
+    pass
+except (MyException, NotImplemented):
+    # NotImplemented is not an exception, let's not crash on it.
+    pass
+
+
+try:
+    pass
+except (ValueError, binascii.Error):
+    # binascii.Error is a subclass of ValueError.
+    pass

resources/test/fixtures/B025.py

@@ -0,0 +1,38 @@
+"""
+Should emit:
+B025 - on lines 15, 22, 31
+"""
+
+import pickle
+
+try:
+    a = 1
+except ValueError:
+    a = 2
+finally:
+    a = 3
+
+try:
+    a = 1
+except ValueError:
+    a = 2
+except ValueError:
+    a = 2
+
+try:
+    a = 1
+except pickle.PickleError:
+    a = 2
+except ValueError:
+    a = 2
+except pickle.PickleError:
+    a = 2
+
+try:
+    a = 1
+except (ValueError, TypeError):
+    a = 2
+except ValueError:
+    a = 2
+except (OSError, TypeError):
+    a = 2

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/C409.py

@@ -0,0 +1,3 @@
+t1 = tuple([1, 2])
+t2 = tuple((1, 2))
+t3 = tuple([])

resources/test/fixtures/C410.py

@@ -0,0 +1,4 @@
+l1 = list([1, 2])
+l2 = list((1, 2))
+l3 = list([])
+l4 = list(())

resources/test/fixtures/C415.py

@@ -0,0 +1,9 @@
+lst = [2, 1, 3]
+a = set(lst[::-1])
+b = reversed(lst[::-1])
+c = sorted(lst[::-1])
+d = sorted(lst[::-1], reverse=True)
+e = set(lst[2:-1])
+f = set(lst[:1:-1])
+g = set(lst[::1])
+h = set(lst[::-2])

resources/test/fixtures/D.py

@@ -0,0 +1,534 @@
+# No docstring, so we can test D100
+from functools import wraps
+import os
+from .expected import Expectation
+from typing import overload
+
+
+expectation = Expectation()
+expect = expectation.expect
+
+expect('class_', 'D101: Missing docstring in public class')
+
+
+class class_:
+
+    expect('meta', 'D419: Docstring is empty')
+
+    class meta:
+        """"""
+
+    @expect('D102: Missing docstring in public method')
+    def method(self=None):
+        pass
+
+    def _ok_since_private(self=None):
+        pass
+
+    @overload
+    def overloaded_method(self, a: int) -> str:
+        ...
+
+    @overload
+    def overloaded_method(self, a: str) -> str:
+        """Foo bar documentation."""
+        ...
+
+    def overloaded_method(a):
+        """Foo bar documentation."""
+        return str(a)
+
+    expect('overloaded_method',
+           "D418: Function/ Method decorated with @overload"
+           " shouldn't contain a docstring")
+
+    @property
+    def foo(self):
+        """The foo of the thing, which isn't in imperitive mood."""
+        return "hello"
+
+    @expect('D102: Missing docstring in public method')
+    def __new__(self=None):
+        pass
+
+    @expect('D107: Missing docstring in __init__')
+    def __init__(self=None):
+        pass
+
+    @expect('D105: Missing docstring in magic method')
+    def __str__(self=None):
+        pass
+
+    @expect('D102: Missing docstring in public method')
+    def __call__(self=None, x=None, y=None, z=None):
+        pass
+
+
+@expect('D419: Docstring is empty')
+def function():
+    """ """
+    def ok_since_nested():
+        pass
+
+    @expect('D419: Docstring is empty')
+    def nested():
+        ''
+
+
+def function_with_nesting():
+    """Foo bar documentation."""
+    @overload
+    def nested_overloaded_func(a: int) -> str:
+        ...
+
+    @overload
+    def nested_overloaded_func(a: str) -> str:
+        """Foo bar documentation."""
+        ...
+
+    def nested_overloaded_func(a):
+        """Foo bar documentation."""
+        return str(a)
+
+
+expect('nested_overloaded_func',
+       "D418: Function/ Method decorated with @overload"
+       " shouldn't contain a docstring")
+
+
+@overload
+def overloaded_func(a: int) -> str:
+    ...
+
+
+@overload
+def overloaded_func(a: str) -> str:
+    """Foo bar documentation."""
+    ...
+
+
+def overloaded_func(a):
+    """Foo bar documentation."""
+    return str(a)
+
+
+expect('overloaded_func',
+       "D418: Function/ Method decorated with @overload"
+       " shouldn't contain a docstring")
+
+
+@expect('D200: One-line docstring should fit on one line with quotes '
+        '(found 3)')
+@expect('D212: Multi-line docstring summary should start at the first line')
+def asdlkfasd():
+    """
+    Wrong.
+    """
+
+
+@expect('D201: No blank lines allowed before function docstring (found 1)')
+def leading_space():
+
+    """Leading space."""
+
+
+@expect('D202: No blank lines allowed after function docstring (found 1)')
+def trailing_space():
+    """Leading space."""
+
+    pass
+
+
+@expect('D201: No blank lines allowed before function docstring (found 1)')
+@expect('D202: No blank lines allowed after function docstring (found 1)')
+def trailing_and_leading_space():
+
+    """Trailing and leading space."""
+
+    pass
+
+
+expect('LeadingSpaceMissing',
+       'D203: 1 blank line required before class docstring (found 0)')
+
+
+class LeadingSpaceMissing:
+    """Leading space missing."""
+
+
+expect('WithLeadingSpace',
+       'D211: No blank lines allowed before class docstring (found 1)')
+
+
+class WithLeadingSpace:
+
+    """With leading space."""
+
+
+expect('TrailingSpace',
+       'D204: 1 blank line required after class docstring (found 0)')
+expect('TrailingSpace',
+       'D211: No blank lines allowed before class docstring (found 1)')
+
+
+class TrailingSpace:
+
+    """TrailingSpace."""
+    pass
+
+
+expect('LeadingAndTrailingSpaceMissing',
+       'D203: 1 blank line required before class docstring (found 0)')
+expect('LeadingAndTrailingSpaceMissing',
+       'D204: 1 blank line required after class docstring (found 0)')
+
+
+class LeadingAndTrailingSpaceMissing:
+    """Leading and trailing space missing."""
+    pass
+
+
+@expect('D205: 1 blank line required between summary line and description '
+        '(found 0)')
+@expect('D213: Multi-line docstring summary should start at the second line')
+def multi_line_zero_separating_blanks():
+    """Summary.
+    Description.
+
+    """
+
+
+@expect('D205: 1 blank line required between summary line and description '
+        '(found 2)')
+@expect('D213: Multi-line docstring summary should start at the second line')
+def multi_line_two_separating_blanks():
+    """Summary.
+
+
+    Description.
+
+    """
+
+
+@expect('D213: Multi-line docstring summary should start at the second line')
+def multi_line_one_separating_blanks():
+    """Summary.
+
+    Description.
+
+    """
+
+
+@expect('D207: Docstring is under-indented')
+@expect('D213: Multi-line docstring summary should start at the second line')
+def asdfsdf():
+    """Summary.
+
+Description.
+
+    """
+
+
+@expect('D207: Docstring is under-indented')
+@expect('D213: Multi-line docstring summary should start at the second line')
+def asdsdfsdffsdf():
+    """Summary.
+
+    Description.
+
+"""
+
+
+@expect('D208: Docstring is over-indented')
+@expect('D213: Multi-line docstring summary should start at the second line')
+def asdfsdsdf24():
+    """Summary.
+
+       Description.
+
+    """
+
+
+@expect('D208: Docstring is over-indented')
+@expect('D213: Multi-line docstring summary should start at the second line')
+def asdfsdsdfsdf24():
+    """Summary.
+
+    Description.
+
+        """
+
+
+@expect('D208: Docstring is over-indented')
+@expect('D213: Multi-line docstring summary should start at the second line')
+def asdfsdfsdsdsdfsdf24():
+    """Summary.
+
+        Description.
+
+    """
+
+
+@expect('D209: Multi-line docstring closing quotes should be on a separate '
+        'line')
+@expect('D213: Multi-line docstring summary should start at the second line')
+def asdfljdf24():
+    """Summary.
+
+    Description."""
+
+
+@expect('D210: No whitespaces allowed surrounding docstring text')
+def endswith():
+    """Whitespace at the end. """
+
+
+@expect('D210: No whitespaces allowed surrounding docstring text')
+def around():
+    """ Whitespace at everywhere. """
+
+
+@expect('D210: No whitespaces allowed surrounding docstring text')
+@expect('D213: Multi-line docstring summary should start at the second line')
+def multiline():
+    """ Whitespace at the beginning.
+
+    This is the end.
+    """
+
+
+@expect('D300: Use """triple double quotes""" (found \'\'\'-quotes)')
+def triple_single_quotes_raw():
+    r'''Summary.'''
+
+
+@expect('D300: Use """triple double quotes""" (found \'\'\'-quotes)')
+def triple_single_quotes_raw_uppercase():
+    R'''Summary.'''
+
+
+@expect('D300: Use """triple double quotes""" (found \'-quotes)')
+def single_quotes_raw():
+    r'Summary.'
+
+
+@expect('D300: Use """triple double quotes""" (found \'-quotes)')
+def single_quotes_raw_uppercase():
+    R'Summary.'
+
+
+@expect('D300: Use """triple double quotes""" (found \'-quotes)')
+@expect('D301: Use r""" if any backslashes in a docstring')
+def single_quotes_raw_uppercase_backslash():
+    R'Sum\mary.'
+
+
+@expect('D301: Use r""" if any backslashes in a docstring')
+def double_quotes_backslash():
+    """Sum\\mary."""
+
+
+@expect('D301: Use r""" if any backslashes in a docstring')
+def double_quotes_backslash_uppercase():
+    R"""Sum\\mary."""
+
+
+@expect('D213: Multi-line docstring summary should start at the second line')
+def exceptions_of_D301():
+    """Exclude some backslashes from D301.
+
+    In particular, line continuations \
+    and unicode literals \u0394 and \N{GREEK CAPITAL LETTER DELTA}.
+    They are considered to be intentionally unescaped.
+    """
+
+
+@expect("D400: First line should end with a period (not 'y')")
+@expect("D415: First line should end with a period, question mark, "
+        "or exclamation point (not 'y')")
+def lwnlkjl():
+    """Summary"""
+
+
+@expect("D401: First line should be in imperative mood "
+        "(perhaps 'Return', not 'Returns')")
+def liouiwnlkjl():
+    """Returns foo."""
+
+
+@expect("D401: First line should be in imperative mood; try rephrasing "
+        "(found 'Constructor')")
+def sdgfsdg23245():
+    """Constructor for a foo."""
+
+
+@expect("D401: First line should be in imperative mood; try rephrasing "
+        "(found 'Constructor')")
+def sdgfsdg23245777():
+    """Constructor."""
+
+
+@expect('D402: First line should not be the function\'s "signature"')
+def foobar():
+    """Signature: foobar()."""
+
+
+@expect('D213: Multi-line docstring summary should start at the second line')
+def new_209():
+    """First line.
+
+    More lines.
+    """
+    pass
+
+
+@expect('D213: Multi-line docstring summary should start at the second line')
+def old_209():
+    """One liner.
+
+    Multi-line comments. OK to have extra blank line
+
+    """
+
+
+@expect("D103: Missing docstring in public function")
+def oneliner_d102(): return
+
+
+@expect("D400: First line should end with a period (not 'r')")
+@expect("D415: First line should end with a period, question mark,"
+        " or exclamation point (not 'r')")
+def oneliner_withdoc(): """One liner"""
+
+
+def ignored_decorator(func):   # noqa: D400,D401,D415
+    """Runs something"""
+    func()
+    pass
+
+
+def decorator_for_test(func):   # noqa: D400,D401,D415
+    """Runs something"""
+    func()
+    pass
+
+
+@ignored_decorator
+def oneliner_ignored_decorator(): """One liner"""
+
+
+@decorator_for_test
+@expect("D400: First line should end with a period (not 'r')")
+@expect("D415: First line should end with a period, question mark,"
+        " or exclamation point (not 'r')")
+def oneliner_with_decorator_expecting_errors(): """One liner"""
+
+
+@decorator_for_test
+def valid_oneliner_with_decorator(): """One liner."""
+
+
+@expect("D207: Docstring is under-indented")
+@expect('D213: Multi-line docstring summary should start at the second line')
+def docstring_start_in_same_line(): """First Line.
+
+    Second Line
+    """
+
+
+def function_with_lambda_arg(x=lambda y: y):
+    """Wrap the given lambda."""
+
+
+@expect('D213: Multi-line docstring summary should start at the second line')
+def a_following_valid_function(x=None):
+    """Check for a bug where the previous function caused an assertion.
+
+    The assertion was caused in the next function, so this one is necessary.
+
+    """
+
+
+def outer_function():
+    """Do something."""
+    def inner_function():
+        """Do inner something."""
+        return 0
+
+
+@expect("D400: First line should end with a period (not 'g')")
+@expect("D401: First line should be in imperative mood "
+        "(perhaps 'Run', not 'Runs')")
+@expect("D415: First line should end with a period, question mark, "
+        "or exclamation point (not 'g')")
+def docstring_bad():
+    """Runs something"""
+    pass
+
+
+def docstring_bad_ignore_all():  # noqa
+    """Runs something"""
+    pass
+
+
+def docstring_bad_ignore_one():  # noqa: D400,D401,D415
+    """Runs something"""
+    pass
+
+
+@expect("D401: First line should be in imperative mood "
+        "(perhaps 'Run', not 'Runs')")
+def docstring_ignore_some_violations_but_catch_D401():  # noqa: E501,D400,D415
+    """Runs something"""
+    pass
+
+
+@expect(
+    "D401: First line should be in imperative mood "
+    "(perhaps 'Initiate', not 'Initiates')"
+)
+def docstring_initiates():
+    """Initiates the process."""
+
+
+@expect(
+    "D401: First line should be in imperative mood "
+    "(perhaps 'Initialize', not 'Initializes')"
+)
+def docstring_initializes():
+    """Initializes the process."""
+
+
+@wraps(docstring_bad_ignore_one)
+def bad_decorated_function():
+    """Bad (E501) but decorated"""
+    pass
+
+
+def valid_google_string():  # noqa: D400
+    """Test a valid something!"""
+
+
+@expect("D415: First line should end with a period, question mark, "
+        "or exclamation point (not 'g')")
+def bad_google_string():  # noqa: D400
+    """Test a valid something"""
+
+
+# This is reproducing a bug where AttributeError is raised when parsing class
+# parameters as functions for Google / Numpy conventions.
+class Blah:  # noqa: D203,D213
+    """A Blah.
+
+    Parameters
+    ----------
+    x : int
+
+    """
+
+    def __init__(self, x):
+        pass
+
+
+expect(os.path.normcase(__file__ if __file__[-1] != 'c' else __file__[:-1]),
+       'D100: Missing docstring in public module')

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/F401.py

@@ -1,41 +0,0 @@
-from __future__ import all_feature_names
-import os
-import functools
-from datetime import datetime
-from collections import (
-    Counter,
-    OrderedDict,
-    namedtuple,
-)
-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 blah import ClassA, ClassB, ClassC
-
-if TYPING_CHECK:
-    from models import Fruit, Nut, Vegetable
-
-
-class X:
-    datetime: datetime
-    foo: Type["NamedTuple"]
-
-    def a(self) -> "namedtuple":
-        x = os.environ["1"]
-        y = Counter()
-        z = multiprocessing.pool.ThreadPool()
-
-
-__all__ = ["ClassA"] + ["ClassB"]
-__all__ += ["ClassC"]
-
-X = TypeVar("X")
-Y = TypeVar("Y", bound="Dict")
-Z = TypeVar("Z", "List", "Set")
-
-a = list["Fruit"]
-b = Union["Nut", None]
-c = cast("Vegetable", b)

resources/test/fixtures/F401_0.py

@@ -0,0 +1,88 @@
+from __future__ import all_feature_names
+import functools, os
+from datetime import datetime
+from collections import (
+    Counter,
+    OrderedDict,
+    namedtuple,
+)
+import multiprocessing.pool
+import multiprocessing.process
+import logging.config
+import logging.handlers
+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 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"]
+
+    def a(self) -> "namedtuple":
+        x = os.environ["1"]
+        y = Counter()
+        z = multiprocessing.pool.ThreadPool()
+
+    def b(self) -> None:
+        import pickle
+
+
+__all__ = ["ClassA"] + ["ClassB"]
+__all__ += ["ClassC"]
+
+X = TypeVar("X")
+Y = TypeVar("Y", bound="Dict")
+Z = TypeVar("Z", "List", "Set")
+
+a = list["Fruit"]
+b = Union["Nut", None]
+c = cast("Vegetable", b)
+
+Field = lambda default=MISSING: field(default=default)
+
+
+# Test: access a sub-importation via an alias.
+import pyarrow as pa
+import pyarrow.csv
+
+print(pa.csv.read_csv("test.csv"))
+
+
+# Test: referencing an import via TypeAlias.
+import sys
+
+import numpy as np
+
+if sys.version_info >= (3, 10):
+    from typing import TypeAlias
+else:
+    from typing_extensions import TypeAlias
+
+
+CustomInt: TypeAlias = "np.int8 | np.int16"

resources/test/fixtures/F401_1.py

@@ -0,0 +1,5 @@
+"""Access a sub-importation via an alias."""
+import pyarrow as pa
+import pyarrow.csv
+
+print(pa.csv.read_csv("test.csv"))

resources/test/fixtures/F401_2.py

@@ -0,0 +1,12 @@
+"""Test: referencing an import via TypeAlias."""
+import sys
+
+import numpy as np
+
+if sys.version_info >= (3, 10):
+    from typing import TypeAlias
+else:
+    from typing_extensions import TypeAlias
+
+
+CustomInt: TypeAlias = "np.int8 | np.int16"

resources/test/fixtures/F401_3.py

@@ -0,0 +1,14 @@
+"""Test: referencing an import via TypeAlias (with future annotations)."""
+from __future__ import annotations
+
+import sys
+
+import numpy as np
+
+if sys.version_info >= (3, 10):
+    from typing import TypeAlias
+else:
+    from typing_extensions import TypeAlias
+
+
+CustomInt: TypeAlias = np.int8 | np.int16

resources/test/fixtures/F401_4.py

@@ -0,0 +1,14 @@
+"""Test: referencing an import via TypeAlias (with future annotations and quotes)."""
+from __future__ import annotations
+
+import sys
+
+import numpy as np
+
+if sys.version_info >= (3, 10):
+    from typing import TypeAlias
+else:
+    from typing_extensions import TypeAlias
+
+
+CustomInt: TypeAlias = "np.int8 | np.int16"

resources/test/fixtures/F404.py

@@ -1,4 +1,3 @@
-from __future__ import print_function
 """Docstring"""
 from __future__ import absolute_import
 

resources/test/fixtures/F821.py

@@ -89,3 +89,45 @@ 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,
+    ]
+
+
+def in_ipython_notebook() -> bool:
+    try:
+        # autoimported by notebooks
+        get_ipython()  # type: ignore[name-defined]
+    except NameError:
+        return False  # not in notebook
+    return True

resources/test/fixtures/M001.py

@@ -15,6 +15,9 @@ def f() -> None:
     # Invalid
     d = 1  # noqa: F841, E501
 
+    # Invalid (and unimplemented)
+    d = 1  # noqa: F841, W191
+
 
 # Valid
 _ = """Lorem ipsum dolor sit amet.

resources/test/fixtures/R002.py

@@ -1,3 +0,0 @@
-self.assertEquals (1, 2)
-self.assertEquals(1, 2)
-self.assertEqual(3, 4)

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/U005.py

@@ -0,0 +1,10 @@
+import unittest
+
+
+class Suite(unittest.TestCase):
+    def test(self) -> None:
+        self.assertEquals (1, 2)
+        self.assertEquals(1, 2)
+        self.assertEqual(3, 4)
+        self.failUnlessAlmostEqual(1, 1.1)
+        self.assertNotRegexpMatches("a", "b")

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/U008.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/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/future_annotations.py

@@ -2,7 +2,10 @@ from __future__ import annotations
 
 from dataclasses import dataclass
 
-from models import Fruit, Nut
+from models import (
+    Fruit,
+    Nut,
+)
 
 
 @dataclass

src/ast.rs

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

src/ast/checks.rs

@@ -1,654 +0,0 @@
-use std::collections::BTreeSet;
-
-use itertools::izip;
-use regex::Regex;
-use rustpython_parser::ast::{
-    Arg, Arguments, Cmpop, Constant, Excepthandler, ExcepthandlerKind, Expr, ExprKind, Keyword,
-    Location, Stmt, StmtKind, Unaryop,
-};
-
-use crate::ast::operations::SourceCodeLocator;
-use crate::ast::types::{Binding, BindingKind, CheckLocator, FunctionScope, Scope, ScopeKind};
-use crate::autofix::{fixer, fixes};
-use crate::checks::{Check, CheckKind, Fix, RejectedCmpop};
-
-/// Check IfTuple compliance.
-pub fn check_if_tuple(test: &Expr, location: Location) -> Option<Check> {
-    if let ExprKind::Tuple { elts, .. } = &test.node {
-        if !elts.is_empty() {
-            return Some(Check::new(CheckKind::IfTuple, location));
-        }
-    }
-    None
-}
-
-/// Check AssertTuple compliance.
-pub fn check_assert_tuple(test: &Expr, location: Location) -> Option<Check> {
-    if let ExprKind::Tuple { elts, .. } = &test.node {
-        if !elts.is_empty() {
-            return Some(Check::new(CheckKind::AssertTuple, location));
-        }
-    }
-    None
-}
-
-/// Check NotInTest and NotIsTest compliance.
-pub fn check_not_tests(
-    op: &Unaryop,
-    operand: &Expr,
-    check_not_in: bool,
-    check_not_is: bool,
-    locator: &dyn CheckLocator,
-) -> Vec<Check> {
-    let mut checks: Vec<Check> = vec![];
-
-    if matches!(op, Unaryop::Not) {
-        if let ExprKind::Compare { ops, .. } = &operand.node {
-            for op in ops {
-                match op {
-                    Cmpop::In => {
-                        if check_not_in {
-                            checks.push(Check::new(
-                                CheckKind::NotInTest,
-                                locator.locate_check(operand.location),
-                            ));
-                        }
-                    }
-                    Cmpop::Is => {
-                        if check_not_is {
-                            checks.push(Check::new(
-                                CheckKind::NotIsTest,
-                                locator.locate_check(operand.location),
-                            ));
-                        }
-                    }
-                    _ => {}
-                }
-            }
-        }
-    }
-
-    checks
-}
-
-/// Check UnusedVariable compliance.
-pub fn check_unused_variables(
-    scope: &Scope,
-    locator: &dyn CheckLocator,
-    dummy_variable_rgx: &Regex,
-) -> Vec<Check> {
-    let mut checks: Vec<Check> = vec![];
-
-    if matches!(
-        scope.kind,
-        ScopeKind::Function(FunctionScope { uses_locals: true })
-    ) {
-        return checks;
-    }
-
-    for (name, binding) in scope.values.iter() {
-        if binding.used.is_none()
-            && matches!(binding.kind, BindingKind::Assignment)
-            && !dummy_variable_rgx.is_match(name)
-            && name != "__tracebackhide__"
-            && name != "__traceback_info__"
-            && name != "__traceback_supplement__"
-        {
-            checks.push(Check::new(
-                CheckKind::UnusedVariable(name.to_string()),
-                locator.locate_check(binding.location),
-            ));
-        }
-    }
-
-    checks
-}
-
-/// Check DoNotAssignLambda compliance.
-pub fn check_do_not_assign_lambda(value: &Expr, location: Location) -> Option<Check> {
-    if let ExprKind::Lambda { .. } = &value.node {
-        Some(Check::new(CheckKind::DoNotAssignLambda, location))
-    } else {
-        None
-    }
-}
-
-fn is_ambiguous_name(name: &str) -> bool {
-    name == "l" || name == "I" || name == "O"
-}
-
-/// Check AmbiguousVariableName compliance.
-pub fn check_ambiguous_variable_name(name: &str, location: Location) -> Option<Check> {
-    if is_ambiguous_name(name) {
-        Some(Check::new(
-            CheckKind::AmbiguousVariableName(name.to_string()),
-            location,
-        ))
-    } else {
-        None
-    }
-}
-
-/// Check AmbiguousClassName compliance.
-pub fn check_ambiguous_class_name(name: &str, location: Location) -> Option<Check> {
-    if is_ambiguous_name(name) {
-        Some(Check::new(
-            CheckKind::AmbiguousClassName(name.to_string()),
-            location,
-        ))
-    } else {
-        None
-    }
-}
-
-/// Check AmbiguousFunctionName compliance.
-pub fn check_ambiguous_function_name(name: &str, location: Location) -> Option<Check> {
-    if is_ambiguous_name(name) {
-        Some(Check::new(
-            CheckKind::AmbiguousFunctionName(name.to_string()),
-            location,
-        ))
-    } else {
-        None
-    }
-}
-
-/// Check UselessObjectInheritance compliance.
-pub fn check_useless_object_inheritance(
-    stmt: &Stmt,
-    name: &str,
-    bases: &[Expr],
-    keywords: &[Keyword],
-    scope: &Scope,
-    locator: &mut SourceCodeLocator,
-    autofix: &fixer::Mode,
-) -> Option<Check> {
-    for expr in bases {
-        if let ExprKind::Name { id, .. } = &expr.node {
-            if id == "object" {
-                match scope.values.get(id) {
-                    None
-                    | Some(Binding {
-                        kind: BindingKind::Builtin,
-                        ..
-                    }) => {
-                        let mut check = Check::new(
-                            CheckKind::UselessObjectInheritance(name.to_string()),
-                            expr.location,
-                        );
-                        if matches!(autofix, fixer::Mode::Generate | fixer::Mode::Apply) {
-                            if let Some(fix) = fixes::remove_class_def_base(
-                                locator,
-                                &stmt.location,
-                                expr.location,
-                                bases,
-                                keywords,
-                            ) {
-                                check.amend(fix);
-                            }
-                        }
-                        return Some(check);
-                    }
-                    _ => {}
-                }
-            }
-        }
-    }
-
-    None
-}
-
-/// Check DefaultExceptNotLast compliance.
-pub fn check_default_except_not_last(handlers: &Vec<Excepthandler>) -> Option<Check> {
-    for (idx, handler) in handlers.iter().enumerate() {
-        let ExcepthandlerKind::ExceptHandler { type_, .. } = &handler.node;
-        if type_.is_none() && idx < handlers.len() - 1 {
-            return Some(Check::new(
-                CheckKind::DefaultExceptNotLast,
-                handler.location,
-            ));
-        }
-    }
-
-    None
-}
-
-/// Check RaiseNotImplemented compliance.
-pub fn check_raise_not_implemented(expr: &Expr) -> Option<Check> {
-    match &expr.node {
-        ExprKind::Call { func, .. } => {
-            if let ExprKind::Name { id, .. } = &func.node {
-                if id == "NotImplemented" {
-                    return Some(Check::new(CheckKind::RaiseNotImplemented, expr.location));
-                }
-            }
-        }
-        ExprKind::Name { id, .. } => {
-            if id == "NotImplemented" {
-                return Some(Check::new(CheckKind::RaiseNotImplemented, expr.location));
-            }
-        }
-        _ => {}
-    }
-
-    None
-}
-
-/// Check DuplicateArgumentName compliance.
-pub fn check_duplicate_arguments(arguments: &Arguments) -> Vec<Check> {
-    let mut checks: Vec<Check> = vec![];
-
-    // Collect all the arguments into a single vector.
-    let mut all_arguments: Vec<&Arg> = arguments
-        .args
-        .iter()
-        .chain(arguments.posonlyargs.iter())
-        .chain(arguments.kwonlyargs.iter())
-        .collect();
-    if let Some(arg) = &arguments.vararg {
-        all_arguments.push(arg);
-    }
-    if let Some(arg) = &arguments.kwarg {
-        all_arguments.push(arg);
-    }
-
-    // Search for duplicates.
-    let mut idents: BTreeSet<&str> = BTreeSet::new();
-    for arg in all_arguments {
-        let ident = &arg.node.arg;
-        if idents.contains(ident.as_str()) {
-            checks.push(Check::new(CheckKind::DuplicateArgumentName, arg.location));
-        }
-        idents.insert(ident);
-    }
-
-    checks
-}
-
-/// Check AssertEquals compliance.
-pub fn check_assert_equals(expr: &Expr, autofix: &fixer::Mode) -> Option<Check> {
-    if let ExprKind::Attribute { value, attr, .. } = &expr.node {
-        if attr == "assertEquals" {
-            if let ExprKind::Name { id, .. } = &value.node {
-                if id == "self" {
-                    let mut check = Check::new(CheckKind::NoAssertEquals, expr.location);
-                    if matches!(autofix, fixer::Mode::Generate | fixer::Mode::Apply) {
-                        check.amend(Fix {
-                            content: "assertEqual".to_string(),
-                            start: Location::new(expr.location.row(), expr.location.column() + 1),
-                            end: Location::new(
-                                expr.location.row(),
-                                expr.location.column() + 1 + "assertEquals".len(),
-                            ),
-                            applied: false,
-                        });
-                    }
-                    return Some(check);
-                }
-            }
-        }
-    }
-    None
-}
-
-#[derive(Debug, PartialEq)]
-enum DictionaryKey<'a> {
-    Constant(&'a Constant),
-    Variable(&'a String),
-}
-
-fn convert_to_value(expr: &Expr) -> Option<DictionaryKey> {
-    match &expr.node {
-        ExprKind::Constant { value, .. } => Some(DictionaryKey::Constant(value)),
-        ExprKind::Name { id, .. } => Some(DictionaryKey::Variable(id)),
-        _ => None,
-    }
-}
-
-/// Check MultiValueRepeatedKeyLiteral and MultiValueRepeatedKeyVariable compliance.
-pub fn check_repeated_keys(
-    keys: &Vec<Expr>,
-    check_repeated_literals: bool,
-    check_repeated_variables: bool,
-    locator: &dyn CheckLocator,
-) -> Vec<Check> {
-    let mut checks: Vec<Check> = vec![];
-
-    let num_keys = keys.len();
-    for i in 0..num_keys {
-        let k1 = &keys[i];
-        let v1 = convert_to_value(k1);
-        for k2 in keys.iter().take(num_keys).skip(i + 1) {
-            let v2 = convert_to_value(k2);
-            match (&v1, &v2) {
-                (Some(DictionaryKey::Constant(v1)), Some(DictionaryKey::Constant(v2))) => {
-                    if check_repeated_literals && v1 == v2 {
-                        checks.push(Check::new(
-                            CheckKind::MultiValueRepeatedKeyLiteral,
-                            locator.locate_check(k2.location),
-                        ))
-                    }
-                }
-                (Some(DictionaryKey::Variable(v1)), Some(DictionaryKey::Variable(v2))) => {
-                    if check_repeated_variables && v1 == v2 {
-                        checks.push(Check::new(
-                            CheckKind::MultiValueRepeatedKeyVariable((*v2).to_string()),
-                            locator.locate_check(k2.location),
-                        ))
-                    }
-                }
-                _ => {}
-            }
-        }
-    }
-
-    checks
-}
-
-/// Check TrueFalseComparison and NoneComparison compliance.
-pub fn check_literal_comparisons(
-    left: &Expr,
-    ops: &Vec<Cmpop>,
-    comparators: &Vec<Expr>,
-    check_none_comparisons: bool,
-    check_true_false_comparisons: bool,
-    locator: &dyn CheckLocator,
-) -> Vec<Check> {
-    let mut checks: Vec<Check> = vec![];
-
-    let op = ops.first().unwrap();
-    let comparator = left;
-
-    // Check `left`.
-    if check_none_comparisons
-        && matches!(
-            comparator.node,
-            ExprKind::Constant {
-                value: Constant::None,
-                kind: None
-            }
-        )
-    {
-        if matches!(op, Cmpop::Eq) {
-            checks.push(Check::new(
-                CheckKind::NoneComparison(RejectedCmpop::Eq),
-                locator.locate_check(comparator.location),
-            ));
-        }
-        if matches!(op, Cmpop::NotEq) {
-            checks.push(Check::new(
-                CheckKind::NoneComparison(RejectedCmpop::NotEq),
-                locator.locate_check(comparator.location),
-            ));
-        }
-    }
-
-    if check_true_false_comparisons {
-        if let ExprKind::Constant {
-            value: Constant::Bool(value),
-            kind: None,
-        } = comparator.node
-        {
-            if matches!(op, Cmpop::Eq) {
-                checks.push(Check::new(
-                    CheckKind::TrueFalseComparison(value, RejectedCmpop::Eq),
-                    locator.locate_check(comparator.location),
-                ));
-            }
-            if matches!(op, Cmpop::NotEq) {
-                checks.push(Check::new(
-                    CheckKind::TrueFalseComparison(value, RejectedCmpop::NotEq),
-                    locator.locate_check(comparator.location),
-                ));
-            }
-        }
-    }
-
-    // Check each comparator in order.
-    for (op, comparator) in izip!(ops, comparators) {
-        if check_none_comparisons
-            && matches!(
-                comparator.node,
-                ExprKind::Constant {
-                    value: Constant::None,
-                    kind: None
-                }
-            )
-        {
-            if matches!(op, Cmpop::Eq) {
-                checks.push(Check::new(
-                    CheckKind::NoneComparison(RejectedCmpop::Eq),
-                    locator.locate_check(comparator.location),
-                ));
-            }
-            if matches!(op, Cmpop::NotEq) {
-                checks.push(Check::new(
-                    CheckKind::NoneComparison(RejectedCmpop::NotEq),
-                    locator.locate_check(comparator.location),
-                ));
-            }
-        }
-
-        if check_true_false_comparisons {
-            if let ExprKind::Constant {
-                value: Constant::Bool(value),
-                kind: None,
-            } = comparator.node
-            {
-                if matches!(op, Cmpop::Eq) {
-                    checks.push(Check::new(
-                        CheckKind::TrueFalseComparison(value, RejectedCmpop::Eq),
-                        locator.locate_check(comparator.location),
-                    ));
-                }
-                if matches!(op, Cmpop::NotEq) {
-                    checks.push(Check::new(
-                        CheckKind::TrueFalseComparison(value, RejectedCmpop::NotEq),
-                        locator.locate_check(comparator.location),
-                    ));
-                }
-            }
-        }
-    }
-
-    checks
-}
-
-fn is_constant(expr: &Expr) -> bool {
-    match &expr.node {
-        ExprKind::Constant { .. } => true,
-        ExprKind::Tuple { elts, .. } => elts.iter().all(is_constant),
-        _ => false,
-    }
-}
-
-fn is_singleton(expr: &Expr) -> bool {
-    matches!(
-        expr.node,
-        ExprKind::Constant {
-            value: Constant::None | Constant::Bool(_) | Constant::Ellipsis,
-            ..
-        }
-    )
-}
-
-fn is_constant_non_singleton(expr: &Expr) -> bool {
-    is_constant(expr) && !is_singleton(expr)
-}
-
-/// Check IsLiteral compliance.
-pub fn check_is_literal(
-    left: &Expr,
-    ops: &Vec<Cmpop>,
-    comparators: &Vec<Expr>,
-    location: Location,
-) -> Vec<Check> {
-    let mut checks: Vec<Check> = vec![];
-
-    let mut left = left;
-    for (op, right) in izip!(ops, comparators) {
-        if matches!(op, Cmpop::Is | Cmpop::IsNot)
-            && (is_constant_non_singleton(left) || is_constant_non_singleton(right))
-        {
-            checks.push(Check::new(CheckKind::IsLiteral, location));
-        }
-        left = right;
-    }
-
-    checks
-}
-
-/// Check TypeComparison compliance.
-pub fn check_type_comparison(
-    ops: &Vec<Cmpop>,
-    comparators: &Vec<Expr>,
-    location: Location,
-) -> Vec<Check> {
-    let mut checks: Vec<Check> = vec![];
-
-    for (op, right) in izip!(ops, comparators) {
-        if matches!(op, Cmpop::Is | Cmpop::IsNot | Cmpop::Eq | Cmpop::NotEq) {
-            match &right.node {
-                ExprKind::Call { func, args, .. } => {
-                    if let ExprKind::Name { id, .. } = &func.node {
-                        // Ex) type(False)
-                        if id == "type" {
-                            if let Some(arg) = args.first() {
-                                // Allow comparison for types which are not obvious.
-                                if !matches!(arg.node, ExprKind::Name { .. }) {
-                                    checks.push(Check::new(CheckKind::TypeComparison, location));
-                                }
-                            }
-                        }
-                    }
-                }
-                ExprKind::Attribute { value, .. } => {
-                    if let ExprKind::Name { id, .. } = &value.node {
-                        // Ex) types.IntType
-                        if id == "types" {
-                            checks.push(Check::new(CheckKind::TypeComparison, location));
-                        }
-                    }
-                }
-                _ => {}
-            }
-        }
-    }
-
-    checks
-}
-
-/// Check TwoStarredExpressions and TooManyExpressionsInStarredAssignment compliance.
-pub fn check_starred_expressions(
-    elts: &[Expr],
-    check_too_many_expressions: bool,
-    check_two_starred_expressions: bool,
-    location: Location,
-) -> Option<Check> {
-    let mut has_starred: bool = false;
-    let mut starred_index: Option<usize> = None;
-    for (index, elt) in elts.iter().enumerate() {
-        if matches!(elt.node, ExprKind::Starred { .. }) {
-            if has_starred && check_two_starred_expressions {
-                return Some(Check::new(CheckKind::TwoStarredExpressions, location));
-            }
-            has_starred = true;
-            starred_index = Some(index);
-        }
-    }
-
-    if check_too_many_expressions {
-        if let Some(starred_index) = starred_index {
-            if starred_index >= 1 << 8 || elts.len() - starred_index > 1 << 24 {
-                return Some(Check::new(
-                    CheckKind::TooManyExpressionsInStarredAssignment,
-                    location,
-                ));
-            }
-        }
-    }
-
-    None
-}
-
-/// Check BreakOutsideLoop compliance.
-pub fn check_break_outside_loop(
-    stmt: &Stmt,
-    parents: &[&Stmt],
-    parent_stack: &[usize],
-    locator: &dyn CheckLocator,
-) -> Option<Check> {
-    let mut allowed: bool = false;
-    let mut parent = stmt;
-    for index in parent_stack.iter().rev() {
-        let child = parent;
-        parent = parents[*index];
-        match &parent.node {
-            StmtKind::For { orelse, .. }
-            | StmtKind::AsyncFor { orelse, .. }
-            | StmtKind::While { orelse, .. } => {
-                if !orelse.contains(child) {
-                    allowed = true;
-                    break;
-                }
-            }
-
-            StmtKind::FunctionDef { .. }
-            | StmtKind::AsyncFunctionDef { .. }
-            | StmtKind::ClassDef { .. } => {
-                break;
-            }
-            _ => {}
-        }
-    }
-
-    if !allowed {
-        Some(Check::new(
-            CheckKind::BreakOutsideLoop,
-            locator.locate_check(stmt.location),
-        ))
-    } else {
-        None
-    }
-}
-
-/// Check ContinueOutsideLoop compliance.
-pub fn check_continue_outside_loop(
-    stmt: &Stmt,
-    parents: &[&Stmt],
-    parent_stack: &[usize],
-    locator: &dyn CheckLocator,
-) -> Option<Check> {
-    let mut allowed: bool = false;
-    let mut parent = stmt;
-    for index in parent_stack.iter().rev() {
-        let child = parent;
-        parent = parents[*index];
-        match &parent.node {
-            StmtKind::For { orelse, .. }
-            | StmtKind::AsyncFor { orelse, .. }
-            | StmtKind::While { orelse, .. } => {
-                if !orelse.contains(child) {
-                    allowed = true;
-                    break;
-                }
-            }
-
-            StmtKind::FunctionDef { .. }
-            | StmtKind::AsyncFunctionDef { .. }
-            | StmtKind::ClassDef { .. } => {
-                break;
-            }
-            _ => {}
-        }
-    }
-
-    if !allowed {
-        Some(Check::new(
-            CheckKind::ContinueOutsideLoop,
-            locator.locate_check(stmt.location),
-        ))
-    } else {
-        None
-    }
-}

src/ast/helpers.rs

@@ -0,0 +1,133 @@
+use once_cell::sync::Lazy;
+use regex::Regex;
+use rustpython_ast::{Excepthandler, ExcepthandlerKind, Expr, ExprKind, StmtKind};
+
+use crate::python::typing;
+
+fn compose_call_path_inner<'a>(expr: &'a Expr, parts: &mut Vec<&'a str>) {
+    match &expr.node {
+        ExprKind::Call { func, .. } => {
+            compose_call_path_inner(func, parts);
+        }
+        ExprKind::Attribute { value, attr, .. } => {
+            compose_call_path_inner(value, parts);
+            parts.push(attr);
+        }
+        ExprKind::Name { id, .. } => {
+            parts.push(id);
+        }
+        _ => {}
+    }
+}
+
+pub fn compose_call_path(expr: &Expr) -> Option<String> {
+    let mut segments = vec![];
+    compose_call_path_inner(expr, &mut segments);
+    if segments.is_empty() {
+        None
+    } else {
+        Some(segments.join("."))
+    }
+}
+
+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,
+    }
+}
+
+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,
+    }
+}
+
+static DUNDER_REGEX: Lazy<Regex> = Lazy::new(|| Regex::new(r"__[^\s]+__").unwrap());
+
+pub fn is_assignment_to_a_dunder(node: &StmtKind) -> bool {
+    // Check whether it's an assignment to a dunder, with or without a type annotation.
+    // This is what pycodestyle (as of 2.9.1) does.
+    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,
+    }
+}
+
+/// Extract the names of all handled exceptions.
+pub fn extract_handler_names(handlers: &[Excepthandler]) -> Vec<String> {
+    let mut handler_names = vec![];
+    for handler in handlers {
+        match &handler.node {
+            ExcepthandlerKind::ExceptHandler { type_, .. } => {
+                if let Some(type_) = type_ {
+                    if let ExprKind::Tuple { elts, .. } = &type_.node {
+                        for type_ in elts {
+                            if let Some(name) = compose_call_path(type_) {
+                                handler_names.push(name);
+                            }
+                        }
+                    } else if let Some(name) = compose_call_path(type_) {
+                        handler_names.push(name);
+                    }
+                }
+            }
+        }
+    }
+    handler_names
+}
+
+/// Returns `true` if a call is an argumented `super` invocation.
+pub fn is_super_call_with_arguments(func: &Expr, args: &Vec<Expr>) -> bool {
+    // Check: is this a `super` call?
+    if let ExprKind::Name { id, .. } = &func.node {
+        id == "super" && !args.is_empty()
+    } else {
+        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> {
@@ -134,7 +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() {
@@ -147,4 +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

@@ -1,13 +1,28 @@
 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,
@@ -40,6 +55,12 @@ impl Scope {
     }
 }
 
+#[derive(Clone, Debug)]
+pub struct BindingContext {
+    pub defined_by: usize,
+    pub defined_in: Option<usize>,
+}
+
 #[derive(Clone, Debug)]
 pub enum BindingKind {
     Annotation,
@@ -52,20 +73,27 @@ pub enum BindingKind {
     Definition,
     Export(Vec<String>),
     FutureImportation,
-    Importation(String),
     StarImportation,
-    SubmoduleImportation(String),
+    Importation(String, String, BindingContext),
+    FromImportation(String, String, BindingContext),
+    SubmoduleImportation(String, String, BindingContext),
 }
 
 #[derive(Clone, Debug)]
 pub struct Binding {
     pub kind: BindingKind,
-    pub location: Location,
-    /// Tuple of (scope index, location) indicating the scope and location at which the binding was
+    pub range: Range,
+    /// Tuple of (scope index, range) indicating the scope and range at which the binding was
     /// last used.
-    pub used: Option<(usize, Location)>,
+    pub used: Option<(usize, Range)>,
 }
 
 pub trait CheckLocator {
-    fn locate_check(&self, default: Location) -> Location;
+    fn locate_check(&self, default: Range) -> Range;
+}
+
+#[derive(Clone, Copy, Debug, PartialEq, Eq, PartialOrd, Ord)]
+pub enum ImportKind {
+    Import,
+    ImportFrom,
 }

src/ast/visitor.rs

@@ -4,6 +4,8 @@ use rustpython_parser::ast::{
     PatternKind, Stmt, StmtKind, Unaryop, Withitem,
 };
 
+use crate::ast::helpers::match_name_or_attr;
+
 pub trait Visitor<'a> {
     fn visit_stmt(&mut self, stmt: &'a Stmt) {
         walk_stmt(self, stmt);
@@ -148,7 +150,11 @@ pub fn walk_stmt<'a, V: Visitor<'a> + ?Sized>(visitor: &mut V, stmt: &'a Stmt) {
         } => {
             visitor.visit_annotation(annotation);
             if let Some(expr) = value {
-                visitor.visit_expr(expr);
+                if match_name_or_attr(annotation, "TypeAlias") {
+                    visitor.visit_annotation(expr);
+                } else {
+                    visitor.visit_expr(expr);
+                }
             }
             visitor.visit_expr(target);
         }

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/check_lines.rs

@@ -2,6 +2,7 @@ use std::collections::BTreeMap;
 
 use rustpython_parser::ast::Location;
 
+use crate::ast::types::Range;
 use crate::autofix::fixer;
 use crate::checks::{Check, CheckCode, CheckKind, Fix};
 use crate::noqa;
@@ -31,8 +32,8 @@ pub fn check_lines(
     settings: &Settings,
     autofix: &fixer::Mode,
 ) {
-    let enforce_line_too_long = settings.select.contains(&CheckCode::E501);
-    let enforce_noqa = settings.select.contains(&CheckCode::M001);
+    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();
 
@@ -64,13 +65,13 @@ pub fn check_lines(
                     .or_insert_with(|| (noqa::extract_noqa_directive(lines[noqa_lineno]), vec![]));
 
                 match noqa {
-                    (Directive::All(_), matches) => {
-                        matches.push(check.kind.code().as_str());
+                    (Directive::All(_, _), matches) => {
+                        matches.push(check.kind.code().as_ref());
                         ignored.push(index)
                     }
-                    (Directive::Codes(_, codes), matches) => {
-                        if codes.contains(&check.kind.code().as_str()) {
-                            matches.push(check.kind.code().as_str());
+                    (Directive::Codes(_, _, codes), matches) => {
+                        if codes.contains(&check.kind.code().as_ref()) {
+                            matches.push(check.kind.code().as_ref());
                             ignored.push(index);
                         }
                     }
@@ -89,16 +90,19 @@ pub fn check_lines(
 
                 let check = Check::new(
                     CheckKind::LineTooLong(line_length, settings.line_length),
-                    Location::new(lineno + 1, settings.line_length + 1),
+                    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_str());
+                    (Directive::All(_, _), matches) => {
+                        matches.push(check.kind.code().as_ref());
                     }
-                    (Directive::Codes(_, codes), matches) => {
-                        if codes.contains(&check.kind.code().as_str()) {
-                            matches.push(check.kind.code().as_str());
+                    (Directive::Codes(_, _, codes), matches) => {
+                        if codes.contains(&check.kind.code().as_ref()) {
+                            matches.push(check.kind.code().as_ref());
                         } else {
                             line_checks.push(check);
                         }
@@ -109,56 +113,110 @@ pub fn check_lines(
         }
     }
 
+    // Enforce newlines at end of files.
+    if settings.enabled.contains(&CheckCode::W292) && !contents.ends_with('\n') {
+        // Note: if `lines.last()` is `None`, then `contents` is empty (and so we don't want to
+        // raise W292 anyway).
+        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(column) => {
+                Directive::All(start, end) => {
                     if matches.is_empty() {
                         let mut check = Check::new(
                             CheckKind::UnusedNOQA(None),
-                            Location::new(row + 1, column + 1),
+                            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(),
-                                start: Location::new(row + 1, column + 1),
-                                end: Location::new(row + 1, lines[row].chars().count() + 1),
+                                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(column, codes) => {
+                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);
+                            invalid_codes.push(code.to_string());
                         } else {
-                            valid_codes.push(code);
+                            valid_codes.push(code.to_string());
                         }
                     }
 
                     if !invalid_codes.is_empty() {
                         let mut check = Check::new(
-                            CheckKind::UnusedNOQA(Some(invalid_codes.join(", "))),
-                            Location::new(row + 1, column + 1),
+                            CheckKind::UnusedNOQA(Some(invalid_codes)),
+                            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(),
-                                    start: Location::new(row + 1, column + 1),
-                                    end: Location::new(row + 1, lines[row].chars().count() + 1),
+                                    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(", ")),
-                                    start: Location::new(row + 1, column + 1),
-                                    end: Location::new(row + 1, lines[row].chars().count() + 1),
+                                    location: Location::new(row + 1, start + 1),
+                                    end_location: Location::new(
+                                        row + 1,
+                                        lines[row].chars().count() + 1,
+                                    ),
                                     applied: false,
                                 });
                             }

src/checks.rs

@@ -1,10 +1,15 @@
 use std::str::FromStr;
 
-use anyhow::Result;
+use itertools::Itertools;
 use rustpython_parser::ast::Location;
 use serde::{Deserialize, Serialize};
+use strum_macros::{AsRefStr, EnumIter, EnumString};
 
-pub const DEFAULT_CHECK_CODES: [CheckCode; 42] = [
+use crate::ast::checkers::Primitive;
+use crate::ast::types::Range;
+
+pub const DEFAULT_CHECK_CODES: [CheckCode; 43] = [
+    // pycodestyle errors
     CheckCode::E402,
     CheckCode::E501,
     CheckCode::E711,
@@ -19,6 +24,9 @@ pub const DEFAULT_CHECK_CODES: [CheckCode; 42] = [
     CheckCode::E743,
     CheckCode::E902,
     CheckCode::E999,
+    // pycodestyle warnings
+    CheckCode::W292,
+    // pyflakes
     CheckCode::F401,
     CheckCode::F402,
     CheckCode::F403,
@@ -49,56 +57,22 @@ pub const DEFAULT_CHECK_CODES: [CheckCode; 42] = [
     CheckCode::F901,
 ];
 
-pub const ALL_CHECK_CODES: [CheckCode; 45] = [
-    CheckCode::E402,
-    CheckCode::E501,
-    CheckCode::E711,
-    CheckCode::E712,
-    CheckCode::E713,
-    CheckCode::E714,
-    CheckCode::E721,
-    CheckCode::E722,
-    CheckCode::E731,
-    CheckCode::E741,
-    CheckCode::E742,
-    CheckCode::E743,
-    CheckCode::E902,
-    CheckCode::E999,
-    CheckCode::F401,
-    CheckCode::F402,
-    CheckCode::F403,
-    CheckCode::F404,
-    CheckCode::F405,
-    CheckCode::F406,
-    CheckCode::F407,
-    CheckCode::F541,
-    CheckCode::F601,
-    CheckCode::F602,
-    CheckCode::F621,
-    CheckCode::F622,
-    CheckCode::F631,
-    CheckCode::F632,
-    CheckCode::F633,
-    CheckCode::F634,
-    CheckCode::F701,
-    CheckCode::F702,
-    CheckCode::F704,
-    CheckCode::F706,
-    CheckCode::F707,
-    CheckCode::F722,
-    CheckCode::F821,
-    CheckCode::F822,
-    CheckCode::F823,
-    CheckCode::F831,
-    CheckCode::F841,
-    CheckCode::F901,
-    CheckCode::M001,
-    CheckCode::R001,
-    CheckCode::R002,
-];
-
-#[derive(Debug, PartialEq, Eq, Clone, Serialize, Deserialize, Hash, PartialOrd, Ord)]
+#[derive(
+    AsRefStr,
+    EnumIter,
+    EnumString,
+    Debug,
+    PartialEq,
+    Eq,
+    Clone,
+    Serialize,
+    Deserialize,
+    Hash,
+    PartialOrd,
+    Ord,
+)]
 pub enum CheckCode {
+    // pycodestyle errors
     E402,
     E501,
     E711,
@@ -113,6 +87,9 @@ pub enum CheckCode {
     E743,
     E902,
     E999,
+    // pycodestyle warnings
+    W292,
+    // pyflakes
     F401,
     F402,
     F403,
@@ -141,117 +118,153 @@ pub enum CheckCode {
     F831,
     F841,
     F901,
-    R001,
-    R002,
+    // flake8-builtins
+    A001,
+    A002,
+    A003,
+    // flake8-bugbear
+    B011,
+    B014,
+    B025,
+    // flake8-comprehensions
+    C400,
+    C401,
+    C402,
+    C403,
+    C404,
+    C405,
+    C406,
+    C408,
+    C409,
+    C410,
+    C415,
+    // flake8-print
+    T201,
+    T203,
+    // pyupgrade
+    U001,
+    U002,
+    U003,
+    U004,
+    U005,
+    U006,
+    U007,
+    U008,
+    // pydocstyle
+    D200,
+    D205,
+    D209,
+    D210,
+    D400,
+    D419,
+    // Meta
     M001,
 }
 
-impl FromStr for CheckCode {
-    type Err = anyhow::Error;
+#[allow(clippy::upper_case_acronyms)]
+pub enum LintSource {
+    AST,
+    Lines,
+    FileSystem,
+}
 
-    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),
-            "E721" => Ok(CheckCode::E721),
-            "E722" => Ok(CheckCode::E722),
-            "E731" => Ok(CheckCode::E731),
-            "E741" => Ok(CheckCode::E741),
-            "E742" => Ok(CheckCode::E742),
-            "E743" => Ok(CheckCode::E743),
-            "E902" => Ok(CheckCode::E902),
-            "E999" => Ok(CheckCode::E999),
-            "F401" => Ok(CheckCode::F401),
-            "F402" => Ok(CheckCode::F402),
-            "F403" => Ok(CheckCode::F403),
-            "F404" => Ok(CheckCode::F404),
-            "F405" => Ok(CheckCode::F405),
-            "F406" => Ok(CheckCode::F406),
-            "F407" => Ok(CheckCode::F407),
-            "F541" => Ok(CheckCode::F541),
-            "F601" => Ok(CheckCode::F601),
-            "F602" => Ok(CheckCode::F602),
-            "F621" => Ok(CheckCode::F621),
-            "F622" => Ok(CheckCode::F622),
-            "F631" => Ok(CheckCode::F631),
-            "F632" => Ok(CheckCode::F632),
-            "F633" => Ok(CheckCode::F633),
-            "F634" => Ok(CheckCode::F634),
-            "F701" => Ok(CheckCode::F701),
-            "F702" => Ok(CheckCode::F702),
-            "F704" => Ok(CheckCode::F704),
-            "F706" => Ok(CheckCode::F706),
-            "F707" => Ok(CheckCode::F707),
-            "F722" => Ok(CheckCode::F722),
-            "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),
-            "M001" => Ok(CheckCode::M001),
-            _ => Err(anyhow::anyhow!("Unknown check code: {s}")),
-        }
-    }
+#[derive(Debug, PartialEq, Eq, Serialize, Deserialize)]
+pub enum RejectedCmpop {
+    Eq,
+    NotEq,
+}
+
+#[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,
+    ImportShadowedByLoopVar(String, usize),
+    ImportStarNotPermitted(String),
+    ImportStarUsage(String, Vec<String>),
+    ImportStarUsed(String),
+    InvalidPrintSyntax,
+    IsLiteral,
+    LateFutureImport,
+    LineTooLong(usize, usize),
+    ModuleImportNotAtTopOfFile,
+    MultiValueRepeatedKeyLiteral,
+    MultiValueRepeatedKeyVariable(String),
+    NoneComparison(RejectedCmpop),
+    NotInTest,
+    NotIsTest,
+    RaiseNotImplemented,
+    ReturnOutsideFunction,
+    SyntaxError(String),
+    TrueFalseComparison(bool, RejectedCmpop),
+    TwoStarredExpressions,
+    TypeComparison,
+    UndefinedExport(String),
+    UndefinedLocal(String),
+    UndefinedName(String),
+    UnusedImport(Vec<String>),
+    UnusedVariable(String),
+    YieldOutsideFunction,
+    // pycodestyle warnings
+    NoNewLineAtEndOfFile,
+    // flake8-builtin
+    BuiltinVariableShadowing(String),
+    BuiltinArgumentShadowing(String),
+    BuiltinAttributeShadowing(String),
+    // flake8-bugbear
+    DoNotAssertFalse,
+    DuplicateHandlerException(Vec<String>),
+    DuplicateTryBlockException(String),
+    // flake8-comprehensions
+    UnnecessaryGeneratorList,
+    UnnecessaryGeneratorSet,
+    UnnecessaryGeneratorDict,
+    UnnecessaryListComprehensionSet,
+    UnnecessaryListComprehensionDict,
+    UnnecessaryLiteralSet(String),
+    UnnecessaryLiteralDict(String),
+    UnnecessaryCollectionCall(String),
+    UnnecessaryLiteralWithinTupleCall(String),
+    UnnecessaryLiteralWithinListCall(String),
+    UnnecessarySubscriptReversal(String),
+    // flake8-print
+    PrintFound,
+    PPrintFound,
+    // pyupgrade
+    TypeOfPrimitive(Primitive),
+    UnnecessaryAbspath,
+    UselessMetaclassType,
+    DeprecatedUnittestAlias(String, String),
+    UselessObjectInheritance(String),
+    UsePEP585Annotation(String),
+    UsePEP604Annotation,
+    SuperCallWithParameters,
+    // pydocstyle
+    OneLinerDocstring,
+    BlankLineAfterSummary,
+    NewLineAfterLastParagraph,
+    NoSurroundingWhitespace,
+    EmptyDocstring,
+    DocstringEndsInNonPeriod,
+    // Meta
+    UnusedNOQA(Option<Vec<String>>),
 }
 
 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::E721 => "E721",
-            CheckCode::E722 => "E722",
-            CheckCode::E731 => "E731",
-            CheckCode::E741 => "E741",
-            CheckCode::E742 => "E742",
-            CheckCode::E743 => "E743",
-            CheckCode::E902 => "E902",
-            CheckCode::E999 => "E999",
-            CheckCode::F401 => "F401",
-            CheckCode::F402 => "F402",
-            CheckCode::F403 => "F403",
-            CheckCode::F404 => "F404",
-            CheckCode::F405 => "F405",
-            CheckCode::F406 => "F406",
-            CheckCode::F407 => "F407",
-            CheckCode::F541 => "F541",
-            CheckCode::F601 => "F601",
-            CheckCode::F602 => "F602",
-            CheckCode::F621 => "F621",
-            CheckCode::F622 => "F622",
-            CheckCode::F631 => "F631",
-            CheckCode::F632 => "F632",
-            CheckCode::F633 => "F633",
-            CheckCode::F634 => "F634",
-            CheckCode::F701 => "F701",
-            CheckCode::F702 => "F702",
-            CheckCode::F704 => "F704",
-            CheckCode::F706 => "F706",
-            CheckCode::F707 => "F707",
-            CheckCode::F722 => "F722",
-            CheckCode::F821 => "F821",
-            CheckCode::F822 => "F822",
-            CheckCode::F823 => "F823",
-            CheckCode::F831 => "F831",
-            CheckCode::F841 => "F841",
-            CheckCode::F901 => "F901",
-            CheckCode::R001 => "R001",
-            CheckCode::R002 => "R002",
-            CheckCode::M001 => "M001",
-        }
-    }
-
     /// The source for the check (either the AST, the filesystem, or the physical lines).
     pub fn lint_source(&self) -> &'static LintSource {
         match self {
@@ -264,6 +277,7 @@ impl CheckCode {
     /// 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),
@@ -276,19 +290,24 @@ impl CheckCode {
             CheckCode::E741 => CheckKind::AmbiguousVariableName("...".to_string()),
             CheckCode::E742 => CheckKind::AmbiguousClassName("...".to_string()),
             CheckCode::E743 => CheckKind::AmbiguousFunctionName("...".to_string()),
-            CheckCode::E902 => CheckKind::IOError("...".to_string()),
-            CheckCode::E999 => CheckKind::SyntaxError("...".to_string()),
-            CheckCode::F401 => CheckKind::UnusedImport("...".to_string()),
+            CheckCode::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(), "...".to_string()),
+            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::TooManyExpressionsInStarredAssignment,
+            CheckCode::F621 => CheckKind::ExpressionsInStarAssignment,
             CheckCode::F622 => CheckKind::TwoStarredExpressions,
             CheckCode::F631 => CheckKind::AssertTuple,
             CheckCode::F632 => CheckKind::IsLiteral,
@@ -306,132 +325,67 @@ impl CheckCode {
             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-bugbear
+            CheckCode::B011 => CheckKind::DoNotAssertFalse,
+            CheckCode::B014 => CheckKind::DuplicateHandlerException(vec!["ValueError".to_string()]),
+            CheckCode::B025 => CheckKind::DuplicateTryBlockException("Exception".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())
+            }
+            CheckCode::C409 => {
+                CheckKind::UnnecessaryLiteralWithinTupleCall("<list/tuple>".to_string())
+            }
+            CheckCode::C410 => {
+                CheckKind::UnnecessaryLiteralWithinListCall("<list/tuple>".to_string())
+            }
+            CheckCode::C415 => {
+                CheckKind::UnnecessarySubscriptReversal("<reversed/set/sorted>".to_string())
+            }
+            // 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::DeprecatedUnittestAlias(
+                "assertEquals".to_string(),
+                "assertEqual".to_string(),
+            ),
+            CheckCode::U006 => CheckKind::UsePEP585Annotation("List".to_string()),
+            CheckCode::U007 => CheckKind::UsePEP604Annotation,
+            CheckCode::U008 => CheckKind::SuperCallWithParameters,
+            // pydocstyle
+            CheckCode::D200 => CheckKind::OneLinerDocstring,
+            CheckCode::D205 => CheckKind::BlankLineAfterSummary,
+            CheckCode::D209 => CheckKind::NewLineAfterLastParagraph,
+            CheckCode::D210 => CheckKind::NoSurroundingWhitespace,
+            CheckCode::D400 => CheckKind::DocstringEndsInNonPeriod,
+            CheckCode::D419 => CheckKind::EmptyDocstring,
+            // Meta
             CheckCode::M001 => CheckKind::UnusedNOQA(None),
-            CheckCode::R001 => CheckKind::UselessObjectInheritance("...".to_string()),
-            CheckCode::R002 => CheckKind::NoAssertEquals,
         }
     }
 }
 
-#[allow(clippy::upper_case_acronyms)]
-pub enum LintSource {
-    AST,
-    Lines,
-    FileSystem,
-}
-
-#[derive(Debug, PartialEq, Eq, Serialize, Deserialize)]
-pub enum RejectedCmpop {
-    Eq,
-    NotEq,
-}
-
-#[derive(Debug, PartialEq, Eq, Serialize, Deserialize)]
-pub enum CheckKind {
-    UnusedNOQA(Option<String>),
-    AmbiguousClassName(String),
-    AmbiguousFunctionName(String),
-    AmbiguousVariableName(String),
-    AssertTuple,
-    BreakOutsideLoop,
-    ContinueOutsideLoop,
-    DefaultExceptNotLast,
-    DoNotAssignLambda,
-    DoNotUseBareExcept,
-    DuplicateArgumentName,
-    ForwardAnnotationSyntaxError(String),
-    FStringMissingPlaceholders,
-    FutureFeatureNotDefined(String),
-    IOError(String),
-    IfTuple,
-    ImportShadowedByLoopVar(String, usize),
-    ImportStarNotPermitted(String),
-    ImportStarUsage(String, String),
-    ImportStarUsed(String),
-    InvalidPrintSyntax,
-    IsLiteral,
-    LateFutureImport,
-    LineTooLong(usize, usize),
-    ModuleImportNotAtTopOfFile,
-    MultiValueRepeatedKeyLiteral,
-    MultiValueRepeatedKeyVariable(String),
-    NoAssertEquals,
-    NoneComparison(RejectedCmpop),
-    NotInTest,
-    NotIsTest,
-    RaiseNotImplemented,
-    ReturnOutsideFunction,
-    SyntaxError(String),
-    TooManyExpressionsInStarredAssignment,
-    TrueFalseComparison(bool, RejectedCmpop),
-    TwoStarredExpressions,
-    TypeComparison,
-    UndefinedExport(String),
-    UndefinedLocal(String),
-    UndefinedName(String),
-    UnusedImport(String),
-    UnusedVariable(String),
-    UselessObjectInheritance(String),
-    YieldOutsideFunction,
-}
-
 impl CheckKind {
-    /// The name of the check.
-    pub fn name(&self) -> &'static str {
-        match self {
-            CheckKind::AmbiguousClassName(_) => "AmbiguousClassName",
-            CheckKind::AmbiguousFunctionName(_) => "AmbiguousFunctionName",
-            CheckKind::AmbiguousVariableName(_) => "AmbiguousVariableName",
-            CheckKind::AssertTuple => "AssertTuple",
-            CheckKind::BreakOutsideLoop => "BreakOutsideLoop",
-            CheckKind::ContinueOutsideLoop => "ContinueOutsideLoop",
-            CheckKind::DefaultExceptNotLast => "DefaultExceptNotLast",
-            CheckKind::DoNotAssignLambda => "DoNotAssignLambda",
-            CheckKind::DoNotUseBareExcept => "DoNotUseBareExcept",
-            CheckKind::DuplicateArgumentName => "DuplicateArgumentName",
-            CheckKind::FStringMissingPlaceholders => "FStringMissingPlaceholders",
-            CheckKind::ForwardAnnotationSyntaxError(_) => "ForwardAnnotationSyntaxError",
-            CheckKind::FutureFeatureNotDefined(_) => "FutureFeatureNotDefined",
-            CheckKind::IOError(_) => "IOError",
-            CheckKind::IfTuple => "IfTuple",
-            CheckKind::ImportShadowedByLoopVar(_, _) => "ImportShadowedByLoopVar",
-            CheckKind::ImportStarNotPermitted(_) => "ImportStarNotPermitted",
-            CheckKind::ImportStarUsage(_, _) => "ImportStarUsage",
-            CheckKind::ImportStarUsed(_) => "ImportStarUsed",
-            CheckKind::InvalidPrintSyntax => "InvalidPrintSyntax",
-            CheckKind::IsLiteral => "IsLiteral",
-            CheckKind::LateFutureImport => "LateFutureImport",
-            CheckKind::LineTooLong(_, _) => "LineTooLong",
-            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::SyntaxError(_) => "SyntaxError",
-            CheckKind::TooManyExpressionsInStarredAssignment => {
-                "TooManyExpressionsInStarredAssignment"
-            }
-            CheckKind::TrueFalseComparison(_, _) => "TrueFalseComparison",
-            CheckKind::TwoStarredExpressions => "TwoStarredExpressions",
-            CheckKind::TypeComparison => "TypeComparison",
-            CheckKind::UndefinedExport(_) => "UndefinedExport",
-            CheckKind::UndefinedLocal(_) => "UndefinedLocal",
-            CheckKind::UndefinedName(_) => "UndefinedName",
-            CheckKind::UnusedImport(_) => "UnusedImport",
-            CheckKind::UnusedVariable(_) => "UnusedVariable",
-            CheckKind::UselessObjectInheritance(_) => "UselessObjectInheritance",
-            CheckKind::YieldOutsideFunction => "YieldOutsideFunction",
-            CheckKind::UnusedNOQA(_) => "UnusedNOQA",
-        }
-    }
-
     /// 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,
@@ -458,14 +412,13 @@ impl CheckKind {
             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::SyntaxError(_) => &CheckCode::E999,
-            CheckKind::TooManyExpressionsInStarredAssignment => &CheckCode::F621,
+            CheckKind::ExpressionsInStarAssignment => &CheckCode::F621,
             CheckKind::TrueFalseComparison(_, _) => &CheckCode::E712,
             CheckKind::TwoStarredExpressions => &CheckCode::F622,
             CheckKind::TypeComparison => &CheckCode::E721,
@@ -473,24 +426,66 @@ impl CheckKind {
             CheckKind::UndefinedLocal(_) => &CheckCode::F823,
             CheckKind::UndefinedName(_) => &CheckCode::F821,
             CheckKind::UnusedImport(_) => &CheckCode::F401,
-            CheckKind::UnusedNOQA(_) => &CheckCode::M001,
             CheckKind::UnusedVariable(_) => &CheckCode::F841,
-            CheckKind::UselessObjectInheritance(_) => &CheckCode::R001,
             CheckKind::YieldOutsideFunction => &CheckCode::F704,
+            // pycodestyle warnings
+            CheckKind::NoNewLineAtEndOfFile => &CheckCode::W292,
+            // flake8-builtins
+            CheckKind::BuiltinVariableShadowing(_) => &CheckCode::A001,
+            CheckKind::BuiltinArgumentShadowing(_) => &CheckCode::A002,
+            CheckKind::BuiltinAttributeShadowing(_) => &CheckCode::A003,
+            // flake8-bugbear
+            CheckKind::DoNotAssertFalse => &CheckCode::B011,
+            CheckKind::DuplicateHandlerException(_) => &CheckCode::B014,
+            CheckKind::DuplicateTryBlockException(_) => &CheckCode::B025,
+            // 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,
+            CheckKind::UnnecessaryLiteralWithinTupleCall(..) => &CheckCode::C409,
+            CheckKind::UnnecessaryLiteralWithinListCall(..) => &CheckCode::C410,
+            CheckKind::UnnecessarySubscriptReversal(_) => &CheckCode::C415,
+            // flake8-print
+            CheckKind::PrintFound => &CheckCode::T201,
+            CheckKind::PPrintFound => &CheckCode::T203,
+            // pyupgrade
+            CheckKind::TypeOfPrimitive(_) => &CheckCode::U003,
+            CheckKind::UnnecessaryAbspath => &CheckCode::U002,
+            CheckKind::UselessMetaclassType => &CheckCode::U001,
+            CheckKind::DeprecatedUnittestAlias(_, _) => &CheckCode::U005,
+            CheckKind::UsePEP585Annotation(_) => &CheckCode::U006,
+            CheckKind::UsePEP604Annotation => &CheckCode::U007,
+            CheckKind::UselessObjectInheritance(_) => &CheckCode::U004,
+            CheckKind::SuperCallWithParameters => &CheckCode::U008,
+            // pydocstyle
+            CheckKind::OneLinerDocstring => &CheckCode::D200,
+            CheckKind::BlankLineAfterSummary => &CheckCode::D205,
+            CheckKind::NewLineAfterLastParagraph => &CheckCode::D209,
+            CheckKind::NoSurroundingWhitespace => &CheckCode::D210,
+            CheckKind::DocstringEndsInNonPeriod => &CheckCode::D400,
+            CheckKind::EmptyDocstring => &CheckCode::D419,
+            // 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)
+                format!("Ambiguous class name: `{}`", name)
             }
             CheckKind::AmbiguousFunctionName(name) => {
-                format!("ambiguous function name '{}'", name)
+                format!("Ambiguous function name: `{}`", name)
             }
             CheckKind::AmbiguousVariableName(name) => {
-                format!("ambiguous variable name '{}'", name)
+                format!("Ambiguous variable name: `{}`", name)
             }
             CheckKind::AssertTuple => {
                 "Assert test is a non-empty tuple, which is always `True`".to_string()
@@ -498,7 +493,7 @@ impl CheckKind {
             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()
@@ -508,19 +503,21 @@ impl CheckKind {
                 "Duplicate argument name in function definition".to_string()
             }
             CheckKind::ForwardAnnotationSyntaxError(body) => {
-                format!("syntax error in forward annotation '{body}'")
+                format!("Syntax error in forward annotation: `{body}`")
             }
             CheckKind::FStringMissingPlaceholders => {
                 "f-string without any placeholders".to_string()
             }
             CheckKind::FutureFeatureNotDefined(name) => {
-                format!("future feature '{name}' is not defined")
+                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::InvalidPrintSyntax => "use of >> is invalid with print function".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")
+                format!("Import `{name}` from line {line} shadowed by loop variable")
             }
             CheckKind::ImportStarNotPermitted(name) => {
                 format!("`from {name} import *` only allowed at module level")
@@ -529,11 +526,15 @@ impl CheckKind {
                 format!("`from {name} import *` used; unable to detect undefined names")
             }
             CheckKind::ImportStarUsage(name, sources) => {
-                format!("'{name}' may be undefined, or defined from star imports: {sources}")
+                let sources = sources
+                    .iter()
+                    .map(|source| format!("`{}`", source))
+                    .join(", ");
+                format!("`{name}` may be undefined, or defined from star imports: {sources}")
             }
-            CheckKind::IsLiteral => "use ==/!= to compare constant literals".to_string(),
+            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()
+                "`from __future__` imports must occur at the beginning of the file".to_string()
             }
             CheckKind::LineTooLong(length, limit) => {
                 format!("Line too long ({length} > {limit} characters)")
@@ -547,9 +548,6 @@ 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 => {
@@ -562,11 +560,11 @@ 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::SyntaxError(message) => format!("SyntaxError: {message}"),
-            CheckKind::TooManyExpressionsInStarredAssignment => {
-                "too many expressions in star-unpacking assignment".to_string()
+            CheckKind::ExpressionsInStarAssignment => {
+                "Too many expressions in star-unpacking assignment".to_string()
             }
             CheckKind::TrueFalseComparison(value, op) => match *value {
                 true => match op {
@@ -586,8 +584,8 @@ impl CheckKind {
                     }
                 },
             },
-            CheckKind::TwoStarredExpressions => "two starred expressions in assignment".to_string(),
-            CheckKind::TypeComparison => "do not compare types, use `isinstance()`".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__`")
             }
@@ -597,19 +595,154 @@ impl CheckKind {
             CheckKind::UndefinedName(name) => {
                 format!("Undefined name `{name}`")
             }
-            CheckKind::UnusedImport(name) => format!("`{name}` imported but unused"),
+            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-bugbear
+            CheckKind::DoNotAssertFalse => {
+                "Do not `assert False` (`python -O` removes these calls), raise `AssertionError()`"
+                    .to_string()
+            }
+            CheckKind::DuplicateHandlerException(names) => {
+                if names.len() == 1 {
+                    let name = &names[0];
+                    format!("Exception handler with duplicate exception: `{name}")
+                } else {
+                    let names = names.iter().map(|name| format!("`{name}`")).join(", ");
+                    format!("Exception handler with duplicate exceptions: {names}")
+                }
+            }
+            CheckKind::DuplicateTryBlockException(name) => {
+                format!("try-except block with duplicate exception `{name}`")
+            }
+            // 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")
+            }
+            CheckKind::UnnecessaryLiteralWithinTupleCall(literal) => {
+                if literal == "list" {
+                    format!(
+                        "Unnecessary {literal} literal passed to tuple() - rewrite as a tuple literal"
+                    )
+                } else {
+                    format!(
+                        "Unnecessary {literal} literal passed to tuple() - remove the outer call to tuple()"
+                    )
+                }
+            }
+            CheckKind::UnnecessaryLiteralWithinListCall(literal) => {
+                if literal == "list" {
+                    format!(
+                        "Unnecessary {literal} literal passed to list() - remove the outer call to list()"
+                    )
+                } else {
+                    format!(
+                        "Unnecessary {literal} literal passed to list() - rewrite as a list literal"
+                    )
+                }
+            }
+            CheckKind::UnnecessarySubscriptReversal(func) => {
+                format!("Unnecessary subscript reversal of iterable within {func}()")
+            }
+            // 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::DeprecatedUnittestAlias(alias, target) => {
+                format!("`{}` is deprecated, use `{}` instead", alias, target)
+            }
             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::UnusedNOQA(code) => match code {
+            CheckKind::UsePEP604Annotation => "Use `X | Y` for type annotations".to_string(),
+            CheckKind::SuperCallWithParameters => {
+                "Use `super()` instead of `super(__class__, self)`".to_string()
+            }
+            // pydocstyle
+            CheckKind::OneLinerDocstring => "One-line docstring should fit on one line".to_string(),
+            CheckKind::BlankLineAfterSummary => {
+                "1 blank line required between summary line and description".to_string()
+            }
+            CheckKind::NewLineAfterLastParagraph => {
+                "Multi-line docstring closing quotes should be on a separate line".to_string()
+            }
+            CheckKind::NoSurroundingWhitespace => {
+                "No whitespaces allowed surrounding docstring text".to_string()
+            }
+            CheckKind::DocstringEndsInNonPeriod => {
+                "First line should end with a period".to_string()
+            }
+            CheckKind::EmptyDocstring => "Docstring is empty".to_string(),
+            // Meta
+            CheckKind::UnusedNOQA(codes) => match codes {
                 None => "Unused `noqa` directive".to_string(),
-                Some(code) => format!("Unused `noqa` directive for: {code}"),
+                Some(codes) => {
+                    let codes = codes
+                        .iter()
+                        .map(|code| {
+                            if CheckCode::from_str(code).is_ok() {
+                                code.to_string()
+                            } else {
+                                format!("{code} (not implemented)")
+                            }
+                        })
+                        .join(", ");
+                    format!("Unused `noqa` directive for: {codes}")
+                }
             },
         }
     }
@@ -618,9 +751,20 @@ impl CheckKind {
     pub fn fixable(&self) -> bool {
         matches!(
             self,
-            CheckKind::NoAssertEquals
-                | CheckKind::UselessObjectInheritance(_)
+            CheckKind::DeprecatedUnittestAlias(_, _)
+                | CheckKind::DoNotAssertFalse
+                | CheckKind::DuplicateHandlerException(_)
+                | CheckKind::PPrintFound
+                | CheckKind::PrintFound
+                | CheckKind::SuperCallWithParameters
+                | CheckKind::TypeOfPrimitive(_)
+                | CheckKind::UnnecessaryAbspath
+                | CheckKind::UnusedImport(_)
                 | CheckKind::UnusedNOQA(_)
+                | CheckKind::UselessMetaclassType
+                | CheckKind::UselessObjectInheritance(_)
+                | CheckKind::UsePEP585Annotation(_)
+                | CheckKind::UsePEP604Annotation
         )
     }
 }
@@ -628,8 +772,8 @@ impl CheckKind {
 #[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,
 }
 
@@ -637,14 +781,16 @@ pub struct Fix {
 pub struct Check {
     pub kind: CheckKind,
     pub location: Location,
+    pub end_location: Location,
     pub fix: Option<Fix>,
 }
 
 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,
         }
     }
@@ -653,3 +799,25 @@ impl Check {
         self.fix = Some(fix);
     }
 }
+
+#[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/docstrings.rs

@@ -0,0 +1,198 @@
+use crate::ast::types::Range;
+use crate::check_ast::Checker;
+use crate::checks::{Check, CheckKind};
+use rustpython_ast::{Constant, Expr, ExprKind, Stmt, StmtKind};
+
+#[derive(Debug)]
+pub enum DocstringKind {
+    Module,
+    Function,
+    Class,
+}
+
+#[derive(Debug)]
+pub struct Docstring<'a> {
+    pub kind: DocstringKind,
+    pub parent: Option<&'a Stmt>,
+    pub expr: &'a Expr,
+}
+
+/// Extract a docstring from an expression.
+pub fn extract<'a, 'b>(
+    checker: &'a Checker,
+    stmt: &'b Stmt,
+    expr: &'b Expr,
+) -> Option<Docstring<'b>> {
+    let defined_in = checker
+        .binding_context()
+        .defined_in
+        .map(|index| checker.parents[index]);
+
+    match defined_in {
+        None => {
+            if checker.initial {
+                return Some(Docstring {
+                    kind: DocstringKind::Module,
+                    parent: None,
+                    expr,
+                });
+            }
+        }
+        Some(parent) => {
+            if let StmtKind::FunctionDef { body, .. }
+            | StmtKind::AsyncFunctionDef { body, .. }
+            | StmtKind::ClassDef { body, .. } = &parent.node
+            {
+                if body.first().map(|node| node == stmt).unwrap_or_default() {
+                    return Some(Docstring {
+                        kind: if matches!(&parent.node, StmtKind::ClassDef { .. }) {
+                            DocstringKind::Class
+                        } else {
+                            DocstringKind::Function
+                        },
+                        parent: None,
+                        expr,
+                    });
+                }
+            }
+        }
+    }
+
+    None
+}
+
+pub fn one_liner(checker: &mut Checker, docstring: &Docstring) {
+    if let ExprKind::Constant {
+        value: Constant::Str(string),
+        ..
+    } = &docstring.expr.node
+    {
+        let mut line_count = 0;
+        let mut non_empty_line_count = 0;
+        for line in string.lines() {
+            line_count += 1;
+            if !line.trim().is_empty() {
+                non_empty_line_count += 1;
+            }
+            if non_empty_line_count > 1 {
+                return;
+            }
+        }
+
+        if non_empty_line_count == 1 && line_count > 1 {
+            checker.add_check(Check::new(
+                CheckKind::OneLinerDocstring,
+                Range::from_located(docstring.expr),
+            ));
+        }
+    }
+}
+
+pub fn blank_after_summary(checker: &mut Checker, docstring: &Docstring) {
+    if let ExprKind::Constant {
+        value: Constant::Str(string),
+        ..
+    } = &docstring.expr.node
+    {
+        let mut lines_count = 1;
+        let mut blanks_count = 0;
+        for line in string.trim().lines().skip(1) {
+            lines_count += 1;
+            if line.trim().is_empty() {
+                blanks_count += 1;
+            } else {
+                break;
+            }
+        }
+        if lines_count > 1 && blanks_count != 1 {
+            checker.add_check(Check::new(
+                CheckKind::BlankLineAfterSummary,
+                Range::from_located(docstring.expr),
+            ));
+        }
+    }
+}
+
+pub fn newline_after_last_paragraph(checker: &mut Checker, docstring: &Docstring) {
+    if let ExprKind::Constant {
+        value: Constant::Str(string),
+        ..
+    } = &docstring.expr.node
+    {
+        let mut line_count = 0;
+        for line in string.lines() {
+            if !line.trim().is_empty() {
+                line_count += 1;
+            }
+            if line_count > 1 {
+                let content = checker
+                    .locator
+                    .slice_source_code_range(&Range::from_located(docstring.expr));
+                if let Some(line) = content.lines().last() {
+                    let line = line.trim();
+                    if line != "\"\"\"" && line != "'''" {
+                        checker.add_check(Check::new(
+                            CheckKind::NewLineAfterLastParagraph,
+                            Range::from_located(docstring.expr),
+                        ));
+                    }
+                }
+                return;
+            }
+        }
+    }
+}
+
+pub fn no_surrounding_whitespace(checker: &mut Checker, docstring: &Docstring) {
+    if let ExprKind::Constant {
+        value: Constant::Str(string),
+        ..
+    } = &docstring.expr.node
+    {
+        let mut lines = string.lines();
+        if let Some(line) = lines.next() {
+            if line.trim().is_empty() {
+                return;
+            }
+
+            if line.starts_with(' ') || (matches!(lines.next(), None) && line.ends_with(' ')) {
+                checker.add_check(Check::new(
+                    CheckKind::NoSurroundingWhitespace,
+                    Range::from_located(docstring.expr),
+                ));
+            }
+        }
+    }
+}
+
+pub fn not_empty(checker: &mut Checker, docstring: &Docstring) {
+    if let ExprKind::Constant {
+        value: Constant::Str(string),
+        ..
+    } = &docstring.expr.node
+    {
+        if string.trim().is_empty() {
+            checker.add_check(Check::new(
+                CheckKind::EmptyDocstring,
+                Range::from_located(docstring.expr),
+            ));
+        }
+    }
+}
+
+pub fn ends_with_period(checker: &mut Checker, docstring: &Docstring) {
+    if let ExprKind::Constant {
+        value: Constant::Str(string),
+        ..
+    } = &docstring.expr.node
+    {
+        if let Some(string) = string.lines().next() {
+            if !string.ends_with('.') {
+                checker.add_check(Check::new(
+                    CheckKind::DocstringEndsInNonPeriod,
+                    Range::from_located(docstring.expr),
+                ));
+            }
+        }
+    }
+}

src/fs.rs

@@ -76,7 +76,6 @@ pub fn iter_python_files<'a>(
         .all(|pattern| matches!(pattern, FilePattern::Simple(_)));
 
     WalkDir::new(normalize_path(path))
-        .follow_links(true)
         .into_iter()
         .filter_entry(move |entry| {
             if !has_exclude && !has_extend_exclude {
@@ -112,7 +111,9 @@ pub fn iter_python_files<'a>(
         })
         .filter(|entry| {
             entry.as_ref().map_or(true, |entry| {
-                (entry.depth() == 0 && !entry.file_type().is_dir()) || is_included(entry.path())
+                (entry.depth() == 0 || is_included(entry.path()))
+                    && !entry.file_type().is_dir()
+                    && !(entry.file_type().is_symlink() && entry.path().is_dir())
             })
         })
 }

src/lib.rs

@@ -1,4 +1,13 @@
-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;
@@ -6,12 +15,63 @@ pub mod cache;
 pub mod check_ast;
 mod check_lines;
 pub mod checks;
+pub mod cli;
+pub mod code_gen;
+pub mod docstrings;
 pub mod fs;
 pub mod linter;
 pub mod logging;
 pub mod message;
 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/linter.rs

@@ -1,3 +1,4 @@
+use std::fs::write;
 use std::path::Path;
 
 use anyhow::Result;
@@ -5,18 +6,20 @@ use log::debug;
 use rustpython_parser::lexer::LexResult;
 use rustpython_parser::{lexer, parser};
 
+use crate::ast::types::Range;
 use crate::autofix::fixer;
 use crate::autofix::fixer::fix_file;
 use crate::check_ast::check_ast;
 use crate::check_lines::check_lines;
 use crate::checks::{Check, CheckCode, CheckKind, LintSource};
+use crate::code_gen::SourceGenerator;
 use crate::message::Message;
 use crate::noqa::add_noqa;
 use crate::settings::Settings;
 use crate::{cache, fs, noqa};
 
 /// Collect tokens up to and including the first error.
-fn tokenize(contents: &str) -> Vec<LexResult> {
+pub(crate) fn tokenize(contents: &str) -> Vec<LexResult> {
     let mut tokens: Vec<LexResult> = vec![];
     for tok in lexer::make_tokenizer(contents) {
         let is_err = tok.is_err();
@@ -28,7 +31,7 @@ fn tokenize(contents: &str) -> Vec<LexResult> {
     tokens
 }
 
-fn check_path(
+pub(crate) fn check_path(
     path: &Path,
     contents: &str,
     tokens: Vec<LexResult>,
@@ -41,7 +44,7 @@ fn check_path(
 
     // Run the AST-based checks.
     if settings
-        .select
+        .enabled
         .iter()
         .any(|check_code| matches!(check_code.lint_source(), LintSource::AST))
     {
@@ -50,10 +53,13 @@ fn check_path(
                 checks.extend(check_ast(&python_ast, contents, settings, autofix, path))
             }
             Err(parse_error) => {
-                if settings.select.contains(&CheckCode::E999) {
+                if settings.enabled.contains(&CheckCode::E999) {
                     checks.push(Check::new(
                         CheckKind::SyntaxError(parse_error.error.to_string()),
-                        parse_error.location,
+                        Range {
+                            location: parse_error.location,
+                            end_location: parse_error.location,
+                        },
                     ))
                 }
             }
@@ -115,6 +121,7 @@ pub fn lint_path(
             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();
@@ -146,6 +153,22 @@ pub fn add_noqa_to_path(path: &Path, settings: &Settings) -> Result<usize> {
     add_noqa(&checks, &contents, &noqa_line_for, path)
 }
 
+pub fn autoformat_path(path: &Path) -> Result<()> {
+    // Read the file from disk.
+    let contents = fs::read_file(path)?;
+
+    // Tokenize once.
+    let tokens: Vec<LexResult> = tokenize(&contents);
+
+    // Generate the AST.
+    let python_ast = parser::parse_program_tokens(tokens, "<filename>")?;
+    let mut generator: SourceGenerator = Default::default();
+    generator.unparse_suite(&python_ast)?;
+    write(path, generator.generate()?)?;
+
+    Ok(())
+}
+
 #[cfg(test)]
 mod tests {
     use std::path::Path;
@@ -317,9 +340,93 @@ mod tests {
     }
 
     #[test]
-    fn f401() -> Result<()> {
+    fn w292_0() -> Result<()> {
         let mut checks = check_path(
-            Path::new("./resources/test/fixtures/F401.py"),
+            Path::new("./resources/test/fixtures/W292_0.py"),
+            &settings::Settings::for_rule(CheckCode::W292),
+            &fixer::Mode::Generate,
+        )?;
+        checks.sort_by_key(|check| check.location);
+        insta::assert_yaml_snapshot!(checks);
+        Ok(())
+    }
+
+    #[test]
+    fn w292_1() -> Result<()> {
+        let mut checks = check_path(
+            Path::new("./resources/test/fixtures/W292_1.py"),
+            &settings::Settings::for_rule(CheckCode::W292),
+            &fixer::Mode::Generate,
+        )?;
+        checks.sort_by_key(|check| check.location);
+        insta::assert_yaml_snapshot!(checks);
+        Ok(())
+    }
+
+    #[test]
+    fn w292_2() -> Result<()> {
+        let mut checks = check_path(
+            Path::new("./resources/test/fixtures/W292_2.py"),
+            &settings::Settings::for_rule(CheckCode::W292),
+            &fixer::Mode::Generate,
+        )?;
+        checks.sort_by_key(|check| check.location);
+        insta::assert_yaml_snapshot!(checks);
+        Ok(())
+    }
+
+    #[test]
+    fn f401_0() -> Result<()> {
+        let mut checks = check_path(
+            Path::new("./resources/test/fixtures/F401_0.py"),
+            &settings::Settings::for_rule(CheckCode::F401),
+            &fixer::Mode::Generate,
+        )?;
+        checks.sort_by_key(|check| check.location);
+        insta::assert_yaml_snapshot!(checks);
+        Ok(())
+    }
+
+    #[test]
+    fn f401_1() -> Result<()> {
+        let mut checks = check_path(
+            Path::new("./resources/test/fixtures/F401_1.py"),
+            &settings::Settings::for_rule(CheckCode::F401),
+            &fixer::Mode::Generate,
+        )?;
+        checks.sort_by_key(|check| check.location);
+        insta::assert_yaml_snapshot!(checks);
+        Ok(())
+    }
+
+    #[test]
+    fn f401_2() -> Result<()> {
+        let mut checks = check_path(
+            Path::new("./resources/test/fixtures/F401_2.py"),
+            &settings::Settings::for_rule(CheckCode::F401),
+            &fixer::Mode::Generate,
+        )?;
+        checks.sort_by_key(|check| check.location);
+        insta::assert_yaml_snapshot!(checks);
+        Ok(())
+    }
+
+    #[test]
+    fn f401_3() -> Result<()> {
+        let mut checks = check_path(
+            Path::new("./resources/test/fixtures/F401_3.py"),
+            &settings::Settings::for_rule(CheckCode::F401),
+            &fixer::Mode::Generate,
+        )?;
+        checks.sort_by_key(|check| check.location);
+        insta::assert_yaml_snapshot!(checks);
+        Ok(())
+    }
+
+    #[test]
+    fn f401_4() -> Result<()> {
+        let mut checks = check_path(
+            Path::new("./resources/test/fixtures/F401_4.py"),
             &settings::Settings::for_rule(CheckCode::F401),
             &fixer::Mode::Generate,
         )?;
@@ -655,6 +762,414 @@ mod tests {
         Ok(())
     }
 
+    #[test]
+    fn e999() -> Result<()> {
+        let mut checks = check_path(
+            Path::new("./resources/test/fixtures/E999.py"),
+            &settings::Settings::for_rule(CheckCode::E999),
+            &fixer::Mode::Generate,
+        )?;
+        checks.sort_by_key(|check| check.location);
+        insta::assert_yaml_snapshot!(checks);
+        Ok(())
+    }
+
+    #[test]
+    fn a001() -> Result<()> {
+        let mut checks = check_path(
+            Path::new("./resources/test/fixtures/A001.py"),
+            &settings::Settings::for_rule(CheckCode::A001),
+            &fixer::Mode::Generate,
+        )?;
+        checks.sort_by_key(|check| check.location);
+        insta::assert_yaml_snapshot!(checks);
+        Ok(())
+    }
+
+    #[test]
+    fn a002() -> Result<()> {
+        let mut checks = check_path(
+            Path::new("./resources/test/fixtures/A002.py"),
+            &settings::Settings::for_rule(CheckCode::A002),
+            &fixer::Mode::Generate,
+        )?;
+        checks.sort_by_key(|check| check.location);
+        insta::assert_yaml_snapshot!(checks);
+        Ok(())
+    }
+
+    #[test]
+    fn a003() -> Result<()> {
+        let mut checks = check_path(
+            Path::new("./resources/test/fixtures/A003.py"),
+            &settings::Settings::for_rule(CheckCode::A003),
+            &fixer::Mode::Generate,
+        )?;
+        checks.sort_by_key(|check| check.location);
+        insta::assert_yaml_snapshot!(checks);
+        Ok(())
+    }
+
+    #[test]
+    fn b011() -> Result<()> {
+        let mut checks = check_path(
+            Path::new("./resources/test/fixtures/B011.py"),
+            &settings::Settings::for_rule(CheckCode::B011),
+            &fixer::Mode::Generate,
+        )?;
+        checks.sort_by_key(|check| check.location);
+        insta::assert_yaml_snapshot!(checks);
+        Ok(())
+    }
+
+    #[test]
+    fn b014() -> Result<()> {
+        let mut checks = check_path(
+            Path::new("./resources/test/fixtures/B014.py"),
+            &settings::Settings::for_rule(CheckCode::B014),
+            &fixer::Mode::Generate,
+        )?;
+        checks.sort_by_key(|check| check.location);
+        insta::assert_yaml_snapshot!(checks);
+        Ok(())
+    }
+
+    #[test]
+    fn b025() -> Result<()> {
+        let mut checks = check_path(
+            Path::new("./resources/test/fixtures/B025.py"),
+            &settings::Settings::for_rule(CheckCode::B025),
+            &fixer::Mode::Generate,
+        )?;
+        checks.sort_by_key(|check| check.location);
+        insta::assert_yaml_snapshot!(checks);
+        Ok(())
+    }
+
+    #[test]
+    fn c400() -> Result<()> {
+        let mut checks = check_path(
+            Path::new("./resources/test/fixtures/C400.py"),
+            &settings::Settings::for_rule(CheckCode::C400),
+            &fixer::Mode::Generate,
+        )?;
+        checks.sort_by_key(|check| check.location);
+        insta::assert_yaml_snapshot!(checks);
+        Ok(())
+    }
+
+    #[test]
+    fn c401() -> Result<()> {
+        let mut checks = check_path(
+            Path::new("./resources/test/fixtures/C401.py"),
+            &settings::Settings::for_rule(CheckCode::C401),
+            &fixer::Mode::Generate,
+        )?;
+        checks.sort_by_key(|check| check.location);
+        insta::assert_yaml_snapshot!(checks);
+        Ok(())
+    }
+
+    #[test]
+    fn c402() -> Result<()> {
+        let mut checks = check_path(
+            Path::new("./resources/test/fixtures/C402.py"),
+            &settings::Settings::for_rule(CheckCode::C402),
+            &fixer::Mode::Generate,
+        )?;
+        checks.sort_by_key(|check| check.location);
+        insta::assert_yaml_snapshot!(checks);
+        Ok(())
+    }
+
+    #[test]
+    fn c403() -> Result<()> {
+        let mut checks = check_path(
+            Path::new("./resources/test/fixtures/C403.py"),
+            &settings::Settings::for_rule(CheckCode::C403),
+            &fixer::Mode::Generate,
+        )?;
+        checks.sort_by_key(|check| check.location);
+        insta::assert_yaml_snapshot!(checks);
+        Ok(())
+    }
+
+    #[test]
+    fn c404() -> Result<()> {
+        let mut checks = check_path(
+            Path::new("./resources/test/fixtures/C404.py"),
+            &settings::Settings::for_rule(CheckCode::C404),
+            &fixer::Mode::Generate,
+        )?;
+        checks.sort_by_key(|check| check.location);
+        insta::assert_yaml_snapshot!(checks);
+        Ok(())
+    }
+
+    #[test]
+    fn c405() -> Result<()> {
+        let mut checks = check_path(
+            Path::new("./resources/test/fixtures/C405.py"),
+            &settings::Settings::for_rule(CheckCode::C405),
+            &fixer::Mode::Generate,
+        )?;
+        checks.sort_by_key(|check| check.location);
+        insta::assert_yaml_snapshot!(checks);
+        Ok(())
+    }
+
+    #[test]
+    fn c406() -> Result<()> {
+        let mut checks = check_path(
+            Path::new("./resources/test/fixtures/C406.py"),
+            &settings::Settings::for_rule(CheckCode::C406),
+            &fixer::Mode::Generate,
+        )?;
+        checks.sort_by_key(|check| check.location);
+        insta::assert_yaml_snapshot!(checks);
+        Ok(())
+    }
+
+    #[test]
+    fn c408() -> Result<()> {
+        let mut checks = check_path(
+            Path::new("./resources/test/fixtures/C408.py"),
+            &settings::Settings::for_rule(CheckCode::C408),
+            &fixer::Mode::Generate,
+        )?;
+        checks.sort_by_key(|check| check.location);
+        insta::assert_yaml_snapshot!(checks);
+        Ok(())
+    }
+
+    #[test]
+    fn c409() -> Result<()> {
+        let mut checks = check_path(
+            Path::new("./resources/test/fixtures/C409.py"),
+            &settings::Settings::for_rule(CheckCode::C409),
+            &fixer::Mode::Generate,
+        )?;
+        checks.sort_by_key(|check| check.location);
+        insta::assert_yaml_snapshot!(checks);
+        Ok(())
+    }
+
+    #[test]
+    fn c410() -> Result<()> {
+        let mut checks = check_path(
+            Path::new("./resources/test/fixtures/C410.py"),
+            &settings::Settings::for_rule(CheckCode::C410),
+            &fixer::Mode::Generate,
+        )?;
+        checks.sort_by_key(|check| check.location);
+        insta::assert_yaml_snapshot!(checks);
+        Ok(())
+    }
+
+    #[test]
+    fn c415() -> Result<()> {
+        let mut checks = check_path(
+            Path::new("./resources/test/fixtures/C415.py"),
+            &settings::Settings::for_rule(CheckCode::C415),
+            &fixer::Mode::Generate,
+        )?;
+        checks.sort_by_key(|check| check.location);
+        insta::assert_yaml_snapshot!(checks);
+        Ok(())
+    }
+
+    #[test]
+    fn d200() -> Result<()> {
+        let mut checks = check_path(
+            Path::new("./resources/test/fixtures/D.py"),
+            &settings::Settings::for_rule(CheckCode::D200),
+            &fixer::Mode::Generate,
+        )?;
+        checks.sort_by_key(|check| check.location);
+        insta::assert_yaml_snapshot!(checks);
+        Ok(())
+    }
+
+    #[test]
+    fn d205() -> Result<()> {
+        let mut checks = check_path(
+            Path::new("./resources/test/fixtures/D.py"),
+            &settings::Settings::for_rule(CheckCode::D205),
+            &fixer::Mode::Generate,
+        )?;
+        checks.sort_by_key(|check| check.location);
+        insta::assert_yaml_snapshot!(checks);
+        Ok(())
+    }
+
+    #[test]
+    fn d209() -> Result<()> {
+        let mut checks = check_path(
+            Path::new("./resources/test/fixtures/D.py"),
+            &settings::Settings::for_rule(CheckCode::D209),
+            &fixer::Mode::Generate,
+        )?;
+        checks.sort_by_key(|check| check.location);
+        insta::assert_yaml_snapshot!(checks);
+        Ok(())
+    }
+
+    #[test]
+    fn d210() -> Result<()> {
+        let mut checks = check_path(
+            Path::new("./resources/test/fixtures/D.py"),
+            &settings::Settings::for_rule(CheckCode::D210),
+            &fixer::Mode::Generate,
+        )?;
+        checks.sort_by_key(|check| check.location);
+        insta::assert_yaml_snapshot!(checks);
+        Ok(())
+    }
+
+    #[test]
+    fn d400() -> Result<()> {
+        let mut checks = check_path(
+            Path::new("./resources/test/fixtures/D.py"),
+            &settings::Settings::for_rule(CheckCode::D400),
+            &fixer::Mode::Generate,
+        )?;
+        checks.sort_by_key(|check| check.location);
+        insta::assert_yaml_snapshot!(checks);
+        Ok(())
+    }
+
+    #[test]
+    fn d419() -> Result<()> {
+        let mut checks = check_path(
+            Path::new("./resources/test/fixtures/D.py"),
+            &settings::Settings::for_rule(CheckCode::D419),
+            &fixer::Mode::Generate,
+        )?;
+        checks.sort_by_key(|check| check.location);
+        insta::assert_yaml_snapshot!(checks);
+        Ok(())
+    }
+
+    #[test]
+    fn t201() -> Result<()> {
+        let mut checks = check_path(
+            Path::new("./resources/test/fixtures/T201.py"),
+            &settings::Settings::for_rule(CheckCode::T201),
+            &fixer::Mode::Generate,
+        )?;
+        checks.sort_by_key(|check| check.location);
+        insta::assert_yaml_snapshot!(checks);
+        Ok(())
+    }
+
+    #[test]
+    fn t203() -> Result<()> {
+        let mut checks = check_path(
+            Path::new("./resources/test/fixtures/T203.py"),
+            &settings::Settings::for_rule(CheckCode::T203),
+            &fixer::Mode::Generate,
+        )?;
+        checks.sort_by_key(|check| check.location);
+        insta::assert_yaml_snapshot!(checks);
+        Ok(())
+    }
+
+    #[test]
+    fn u001() -> Result<()> {
+        let mut checks = check_path(
+            Path::new("./resources/test/fixtures/U001.py"),
+            &settings::Settings::for_rule(CheckCode::U001),
+            &fixer::Mode::Generate,
+        )?;
+        checks.sort_by_key(|check| check.location);
+        insta::assert_yaml_snapshot!(checks);
+        Ok(())
+    }
+
+    #[test]
+    fn u002() -> Result<()> {
+        let mut checks = check_path(
+            Path::new("./resources/test/fixtures/U002.py"),
+            &settings::Settings::for_rule(CheckCode::U002),
+            &fixer::Mode::Generate,
+        )?;
+        checks.sort_by_key(|check| check.location);
+        insta::assert_yaml_snapshot!(checks);
+        Ok(())
+    }
+
+    #[test]
+    fn u003() -> Result<()> {
+        let mut checks = check_path(
+            Path::new("./resources/test/fixtures/U003.py"),
+            &settings::Settings::for_rule(CheckCode::U003),
+            &fixer::Mode::Generate,
+        )?;
+        checks.sort_by_key(|check| check.location);
+        insta::assert_yaml_snapshot!(checks);
+        Ok(())
+    }
+
+    #[test]
+    fn u004() -> Result<()> {
+        let mut checks = check_path(
+            Path::new("./resources/test/fixtures/U004.py"),
+            &settings::Settings::for_rule(CheckCode::U004),
+            &fixer::Mode::Generate,
+        )?;
+        checks.sort_by_key(|check| check.location);
+        insta::assert_yaml_snapshot!(checks);
+        Ok(())
+    }
+
+    #[test]
+    fn u005() -> Result<()> {
+        let mut checks = check_path(
+            Path::new("./resources/test/fixtures/U005.py"),
+            &settings::Settings::for_rule(CheckCode::U005),
+            &fixer::Mode::Generate,
+        )?;
+        checks.sort_by_key(|check| check.location);
+        insta::assert_yaml_snapshot!(checks);
+        Ok(())
+    }
+
+    #[test]
+    fn u006() -> Result<()> {
+        let mut checks = check_path(
+            Path::new("./resources/test/fixtures/U006.py"),
+            &settings::Settings::for_rule(CheckCode::U006),
+            &fixer::Mode::Generate,
+        )?;
+        checks.sort_by_key(|check| check.location);
+        insta::assert_yaml_snapshot!(checks);
+        Ok(())
+    }
+
+    #[test]
+    fn u007() -> Result<()> {
+        let mut checks = check_path(
+            Path::new("./resources/test/fixtures/U007.py"),
+            &settings::Settings::for_rule(CheckCode::U007),
+            &fixer::Mode::Generate,
+        )?;
+        checks.sort_by_key(|check| check.location);
+        insta::assert_yaml_snapshot!(checks);
+        Ok(())
+    }
+
+    #[test]
+    fn u008() -> Result<()> {
+        let mut checks = check_path(
+            Path::new("./resources/test/fixtures/U008.py"),
+            &settings::Settings::for_rule(CheckCode::U008),
+            &fixer::Mode::Generate,
+        )?;
+        checks.sort_by_key(|check| check.location);
+        insta::assert_yaml_snapshot!(checks);
+        Ok(())
+    }
+
     #[test]
     fn m001() -> Result<()> {
         let mut checks = check_path(
@@ -667,30 +1182,6 @@ mod tests {
         Ok(())
     }
 
-    #[test]
-    fn r001() -> Result<()> {
-        let mut checks = check_path(
-            Path::new("./resources/test/fixtures/R001.py"),
-            &settings::Settings::for_rule(CheckCode::R001),
-            &fixer::Mode::Generate,
-        )?;
-        checks.sort_by_key(|check| check.location);
-        insta::assert_yaml_snapshot!(checks);
-        Ok(())
-    }
-
-    #[test]
-    fn r002() -> Result<()> {
-        let mut checks = check_path(
-            Path::new("./resources/test/fixtures/R002.py"),
-            &settings::Settings::for_rule(CheckCode::R002),
-            &fixer::Mode::Generate,
-        )?;
-        checks.sort_by_key(|check| check.location);
-        insta::assert_yaml_snapshot!(checks);
-        Ok(())
-    }
-
     #[test]
     fn init() -> Result<()> {
         let mut checks = check_path(
@@ -714,16 +1205,4 @@ mod tests {
         insta::assert_yaml_snapshot!(checks);
         Ok(())
     }
-
-    #[test]
-    fn e999() -> Result<()> {
-        let mut checks = check_path(
-            Path::new("./resources/test/fixtures/E999.py"),
-            &settings::Settings::for_rule(CheckCode::E999),
-            &fixer::Mode::Generate,
-        )?;
-        checks.sort_by_key(|check| check.location);
-        insta::assert_yaml_snapshot!(checks);
-        Ok(())
-    }
 }

src/main.rs

@@ -1,5 +1,3 @@
-extern crate core;
-
 use std::io;
 use std::path::{Path, PathBuf};
 use std::process::ExitCode;
@@ -7,93 +5,33 @@ use std::sync::mpsc::channel;
 use std::time::Instant;
 
 use anyhow::Result;
-use clap::{command, Parser};
+use clap::Parser;
 use colored::Colorize;
 use log::{debug, error};
 use notify::{raw_watcher, RecursiveMode, Watcher};
 use rayon::prelude::*;
-use regex::Regex;
 use walkdir::DirEntry;
 
-use ::ruff::cache;
-use ::ruff::checks::CheckCode;
-use ::ruff::checks::CheckKind;
-use ::ruff::fs::iter_python_files;
-use ::ruff::linter::add_noqa_to_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, StrCheckCodePair};
-use ::ruff::settings::{FilePattern, PerFileIgnore, 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)]
-#[command(author, about = "ruff: An extremely fast Python linter.")]
-#[command(version)]
-struct Cli {
-    #[arg(required = true)]
-    files: Vec<PathBuf>,
-    /// Enable verbose logging.
-    #[arg(short, long)]
-    verbose: bool,
-    /// Disable all logging (but still exit with status code "1" upon detecting errors).
-    #[arg(short, long)]
-    quiet: bool,
-    /// Exit with status code "0", even upon detecting errors.
-    #[arg(short, long)]
-    exit_zero: bool,
-    /// Run in watch mode by re-running whenever files change.
-    #[arg(short, long)]
-    watch: bool,
-    /// Attempt to automatically fix lint errors.
-    #[arg(short, long)]
-    fix: bool,
-    /// Disable cache reads.
-    #[arg(short, long)]
-    no_cache: bool,
-    /// List of error codes to enable.
-    #[arg(long, value_delimiter = ',')]
-    select: Vec<CheckCode>,
-    /// Like --select, but adds additional error codes on top of the selected ones.
-    #[arg(long, value_delimiter = ',')]
-    extend_select: Vec<CheckCode>,
-    /// List of error codes to ignore.
-    #[arg(long, value_delimiter = ',')]
-    ignore: Vec<CheckCode>,
-    /// Like --ignore, but adds additional error codes on top of the ignored ones.
-    #[arg(long, value_delimiter = ',')]
-    extend_ignore: Vec<CheckCode>,
-    /// List of paths, used to exclude files and/or directories from checks.
-    #[arg(long, value_delimiter = ',')]
-    exclude: Vec<String>,
-    /// Like --exclude, but adds additional files and directories on top of the excluded ones.
-    #[arg(long, value_delimiter = ',')]
-    extend_exclude: Vec<String>,
-    /// List of mappings from file pattern to code to exclude
-    #[arg(long, value_delimiter = ',')]
-    per_file_ignores: Vec<StrCheckCodePair>,
-    /// Output serialization format for error messages.
-    #[arg(long, value_enum, default_value_t=SerializationFormat::Text)]
-    format: SerializationFormat,
-    /// See the files ruff will be run against with the current settings.
-    #[arg(long)]
-    show_files: bool,
-    /// See ruff's settings.
-    #[arg(long)]
-    show_settings: bool,
-    /// Enable automatic additions of noqa directives to failing lines.
-    #[arg(long)]
-    add_noqa: bool,
-    /// Regular expression matching the name of dummy variables.
-    #[arg(long)]
-    dummy_variable_rgx: Option<Regex>,
-}
-
 #[cfg(feature = "update-informer")]
 fn check_for_updates() {
     use update_informer::{registry, Check};
@@ -118,8 +56,11 @@ fn check_for_updates() {
     }
 }
 
-fn show_settings(settings: Settings) {
-    println!("{:#?}", CurrentSettings::from_settings(settings));
+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) {
@@ -167,11 +108,12 @@ fn run_once(
             }
             .unwrap_or_else(|(path, message)| {
                 if let Some(path) = path {
-                    if settings.select.contains(&CheckCode::E902) {
+                    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 {
@@ -223,6 +165,33 @@ fn add_noqa(files: &[PathBuf], settings: &Settings) -> Result<usize> {
     Ok(modifications)
 }
 
+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);
+
+    let start = Instant::now();
+    let modifications = paths
+        .par_iter()
+        .map(|entry| {
+            let path = entry.path();
+            autoformat_path(path)
+        })
+        .flatten()
+        .count();
+
+    let duration = start.elapsed();
+    debug!("Auto-formatted files in: {:?}", duration);
+
+    Ok(modifications)
+}
+
 fn inner_main() -> Result<ExitCode> {
     let cli = Cli::parse();
 
@@ -257,7 +226,7 @@ fn inner_main() -> Result<ExitCode> {
         .map(|pair| PerFileIgnore::new(pair, &project_root))
         .collect();
 
-    let mut settings = Settings::from_pyproject(pyproject, project_root)?;
+    let mut settings = RawSettings::from_pyproject(&pyproject, &project_root)?;
     if !exclude.is_empty() {
         settings.exclude = exclude;
     }
@@ -268,17 +237,35 @@ fn inner_main() -> Result<ExitCode> {
         settings.per_file_ignores = per_file_ignores;
     }
     if !cli.select.is_empty() {
-        settings.clear();
-        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() {
-        settings.select(cli.extend_select);
+        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.ignore(&cli.extend_ignore);
+        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;
@@ -288,12 +275,15 @@ fn inner_main() -> Result<ExitCode> {
         eprintln!("Error: specify --show-settings or show-files (not both).");
         return Ok(ExitCode::FAILURE);
     }
-    if cli.show_files {
-        show_files(&cli.files, &settings);
+    if cli.show_settings {
+        show_settings(settings, project_root, pyproject);
         return Ok(ExitCode::SUCCESS);
     }
-    if cli.show_settings {
-        show_settings(settings);
+
+    let settings = Settings::from_raw(settings);
+
+    if cli.show_files {
+        show_files(&cli.files, &settings);
         return Ok(ExitCode::SUCCESS);
     }
 
@@ -309,6 +299,10 @@ fn inner_main() -> Result<ExitCode> {
             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.");
         }
@@ -352,6 +346,11 @@ fn inner_main() -> Result<ExitCode> {
         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 {
@@ -361,7 +360,7 @@ fn inner_main() -> Result<ExitCode> {
         #[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);
         }
     }

src/message.rs

@@ -14,6 +14,7 @@ pub struct Message {
     pub kind: CheckKind,
     pub fixed: bool,
     pub location: Location,
+    pub end_location: Location,
     pub filename: String,
 }
 
@@ -39,13 +40,12 @@ impl fmt::Display for Message {
             f,
             "{}{}{}{}{}{} {} {}",
             relativize_path(Path::new(&self.filename)).white().bold(),
-            // self.filename.white(),
             ":".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

@@ -19,8 +19,8 @@ static SPLIT_COMMA_REGEX: Lazy<Regex> = Lazy::new(|| Regex::new(r"[,\s]").expect
 #[derive(Debug)]
 pub enum Directive<'a> {
     None,
-    All(usize),
-    Codes(usize, Vec<&'a str>),
+    All(usize, usize),
+    Codes(usize, usize, Vec<&'a str>),
 }
 
 pub fn extract_noqa_directive(line: &str) -> Directive {
@@ -29,13 +29,14 @@ pub fn extract_noqa_directive(line: &str) -> Directive {
             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()),
+                None => Directive::All(noqa.start(), noqa.end()),
             },
             None => Directive::None,
         },
@@ -46,10 +47,9 @@ pub fn extract_noqa_directive(line: &str) -> Directive {
 pub fn extract_noqa_line_for(lxr: &[LexResult]) -> Vec<usize> {
     let mut noqa_line_for: Vec<usize> = vec![];
 
-    let mut last_is_string = false;
-    let mut last_seen = usize::MIN;
     let mut min_line = usize::MAX;
     let mut max_line = usize::MIN;
+    let mut in_string = false;
 
     for (start, tok, end) in lxr.iter().flatten() {
         if matches!(tok, Tok::EndOfFile) {
@@ -61,29 +61,20 @@ pub fn extract_noqa_line_for(lxr: &[LexResult]) -> Vec<usize> {
             max_line = max(max_line, start.row());
 
             // For now, we only care about preserving noqa directives across multi-line strings.
-            if last_is_string {
-                noqa_line_for.extend(vec![max_line; (max_line + 1) - min_line]);
-            } else {
-                for i in (min_line - 1)..(max_line) {
+            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 {
-            // Handle empty lines.
-            if start.row() > last_seen {
-                for i in last_seen..(start.row() - 1) {
-                    noqa_line_for.push(i + 1);
-                }
-            }
-
             min_line = min(min_line, start.row());
             max_line = max(max_line, end.row());
         }
-        last_seen = start.row();
-        last_is_string = matches!(tok, Tok::String { .. });
+        in_string = matches!(tok, Tok::String { .. });
     }
 
     noqa_line_for
@@ -113,9 +104,7 @@ fn add_noqa_inner(
             .unwrap_or(lineno);
 
         if !codes.is_empty() {
-            let matches = matches_by_line
-                .entry(noqa_lineno)
-                .or_insert_with(BTreeSet::new);
+            let matches = matches_by_line.entry(noqa_lineno).or_default();
             matches.append(&mut codes);
         }
     }
@@ -133,10 +122,10 @@ fn add_noqa_inner(
                     Directive::None => {
                         output.push_str(line);
                     }
-                    Directive::All(start) => output.push_str(&line[..start]),
-                    Directive::Codes(start, _) => output.push_str(&line[..start]),
+                    Directive::All(start, _) => output.push_str(&line[..start]),
+                    Directive::Codes(start, _, _) => output.push_str(&line[..start]),
                 };
-                let codes: Vec<&str> = codes.iter().map(|code| code.as_str()).collect();
+                let codes: Vec<&str> = codes.iter().map(|code| code.as_ref()).collect();
                 output.push_str("  # noqa: ");
                 output.push_str(&codes.join(", "));
                 output.push('\n');
@@ -166,11 +155,14 @@ mod tests {
     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
@@ -178,7 +170,7 @@ z = x + 1",
         )
         .collect();
         println!("{:?}", extract_noqa_line_for(&lxr));
-        assert_eq!(extract_noqa_line_for(&lxr), vec![1, 2, 3]);
+        assert_eq!(extract_noqa_line_for(&lxr), empty);
 
         let lxr: Vec<LexResult> = lexer::make_tokenizer(
             "
@@ -188,7 +180,7 @@ z = x + 1",
         )
         .collect();
         println!("{:?}", extract_noqa_line_for(&lxr));
-        assert_eq!(extract_noqa_line_for(&lxr), vec![1, 2, 3, 4]);
+        assert_eq!(extract_noqa_line_for(&lxr), empty);
 
         let lxr: Vec<LexResult> = lexer::make_tokenizer(
             "x = 1
@@ -198,7 +190,7 @@ z = x + 1
         )
         .collect();
         println!("{:?}", extract_noqa_line_for(&lxr));
-        assert_eq!(extract_noqa_line_for(&lxr), vec![1, 2, 3]);
+        assert_eq!(extract_noqa_line_for(&lxr), empty);
 
         let lxr: Vec<LexResult> = lexer::make_tokenizer(
             "x = 1
@@ -209,7 +201,7 @@ z = x + 1
         )
         .collect();
         println!("{:?}", extract_noqa_line_for(&lxr));
-        assert_eq!(extract_noqa_line_for(&lxr), vec![1, 2, 3, 4]);
+        assert_eq!(extract_noqa_line_for(&lxr), empty);
 
         let lxr: Vec<LexResult> = lexer::make_tokenizer(
             "x = '''abc
@@ -220,7 +212,28 @@ y = 2
 z = x + 1",
         )
         .collect();
-        assert_eq!(extract_noqa_line_for(&lxr), vec![4, 4, 4, 4, 5, 6]);
+        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(())
     }
@@ -236,7 +249,10 @@ z = x + 1",
 
         let checks = vec![Check::new(
             CheckKind::UnusedVariable("x".to_string()),
-            Location::new(1, 1),
+            Range {
+                location: Location::new(1, 1),
+                end_location: Location::new(1, 1),
+            },
         )];
         let contents = "x = 1";
         let noqa_line_for = vec![1];
@@ -247,11 +263,17 @@ z = x + 1",
         let checks = vec![
             Check::new(
                 CheckKind::AmbiguousVariableName("x".to_string()),
-                Location::new(1, 1),
+                Range {
+                    location: Location::new(1, 1),
+                    end_location: Location::new(1, 1),
+                },
             ),
             Check::new(
                 CheckKind::UnusedVariable("x".to_string()),
-                Location::new(1, 1),
+                Range {
+                    location: Location::new(1, 1),
+                    end_location: Location::new(1, 1),
+                },
             ),
         ];
         let contents = "x = 1  # noqa: E741";
@@ -263,11 +285,17 @@ z = x + 1",
         let checks = vec![
             Check::new(
                 CheckKind::AmbiguousVariableName("x".to_string()),
-                Location::new(1, 1),
+                Range {
+                    location: Location::new(1, 1),
+                    end_location: Location::new(1, 1),
+                },
             ),
             Check::new(
                 CheckKind::UnusedVariable("x".to_string()),
-                Location::new(1, 1),
+                Range {
+                    location: Location::new(1, 1),
+                    end_location: Location::new(1, 1),
+                },
             ),
         ];
         let contents = "x = 1  # noqa";

src/plugins.rs

@@ -0,0 +1,29 @@
+pub use assert_false::assert_false;
+pub use assert_tuple::assert_tuple;
+pub use deprecated_unittest_alias::deprecated_unittest_alias;
+pub use duplicate_exceptions::duplicate_exceptions;
+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_false;
+mod assert_tuple;
+mod deprecated_unittest_alias;
+mod duplicate_exceptions;
+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_false.rs

@@ -0,0 +1,61 @@
+use rustpython_ast::{Constant, Expr, ExprContext, ExprKind, Stmt, StmtKind};
+
+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 assertion_error(msg: &Option<Box<Expr>>) -> Stmt {
+    Stmt::new(
+        Default::default(),
+        Default::default(),
+        StmtKind::Raise {
+            exc: Some(Box::new(Expr::new(
+                Default::default(),
+                Default::default(),
+                ExprKind::Call {
+                    func: Box::new(Expr::new(
+                        Default::default(),
+                        Default::default(),
+                        ExprKind::Name {
+                            id: "AssertionError".to_string(),
+                            ctx: ExprContext::Load,
+                        },
+                    )),
+                    args: if let Some(msg) = msg {
+                        vec![*msg.clone()]
+                    } else {
+                        vec![]
+                    },
+                    keywords: vec![],
+                },
+            ))),
+            cause: None,
+        },
+    )
+}
+
+pub fn assert_false(checker: &mut Checker, stmt: &Stmt, test: &Expr, msg: &Option<Box<Expr>>) {
+    if let ExprKind::Constant {
+        value: Constant::Bool(false),
+        ..
+    } = &test.node
+    {
+        let mut check = Check::new(CheckKind::DoNotAssertFalse, Range::from_located(test));
+        if matches!(checker.autofix, fixer::Mode::Generate | fixer::Mode::Apply) {
+            let mut generator = SourceGenerator::new();
+            if let Ok(()) = generator.unparse_stmt(&assertion_error(msg)) {
+                if let Ok(content) = generator.generate() {
+                    check.amend(Fix {
+                        content,
+                        location: stmt.location,
+                        end_location: stmt.end_location,
+                        applied: false,
+                    })
+                }
+            }
+        }
+        checker.add_check(check);
+    }
+}

src/plugins/assert_tuple.rs

@@ -0,0 +1,13 @@
+use rustpython_ast::{Expr, Stmt};
+
+use crate::ast::checkers;
+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) =
+        checkers::assert_tuple(test, checker.locate_check(Range::from_located(stmt)))
+    {
+        checker.add_check(check);
+    }
+}

src/plugins/deprecated_unittest_alias.rs

@@ -0,0 +1,56 @@
+use std::collections::BTreeMap;
+
+use once_cell::sync::Lazy;
+use rustpython_ast::{Expr, ExprKind, Location};
+
+use crate::ast::types::Range;
+use crate::autofix::fixer;
+use crate::check_ast::Checker;
+use crate::checks::{Check, CheckKind, Fix};
+
+static DEPRECATED_ALIASES: Lazy<BTreeMap<&'static str, &'static str>> = Lazy::new(|| {
+    BTreeMap::from([
+        ("failUnlessEqual", "assertEqual"),
+        ("assertEquals", "assertEqual"),
+        ("failIfEqual", "assertNotEqual"),
+        ("assertNotEquals", "assertNotEqual"),
+        ("failUnless", "assertTrue"),
+        ("assert_", "assertTrue"),
+        ("failIf", "assertFalse"),
+        ("failUnlessRaises", "assertRaises"),
+        ("failUnlessAlmostEqual", "assertAlmostEqual"),
+        ("assertAlmostEquals", "assertAlmostEqual"),
+        ("failIfAlmostEqual", "assertNotAlmostEqual"),
+        ("assertNotAlmostEquals", "assertNotAlmostEqual"),
+        ("assertRegexpMatches", "assertRegex"),
+        ("assertNotRegexpMatches", "assertNotRegex"),
+        ("assertRaisesRegexp", "assertRaisesRegex"),
+    ])
+});
+
+pub fn deprecated_unittest_alias(checker: &mut Checker, expr: &Expr) {
+    if let ExprKind::Attribute { value, attr, .. } = &expr.node {
+        if let Some(target) = DEPRECATED_ALIASES.get(attr.as_str()) {
+            if let ExprKind::Name { id, .. } = &value.node {
+                if id == "self" {
+                    let mut check = Check::new(
+                        CheckKind::DeprecatedUnittestAlias(attr.to_string(), target.to_string()),
+                        Range::from_located(expr),
+                    );
+                    if matches!(checker.autofix, fixer::Mode::Generate | fixer::Mode::Apply) {
+                        check.amend(Fix {
+                            content: format!("self.{}", target),
+                            location: Location::new(expr.location.row(), expr.location.column()),
+                            end_location: Location::new(
+                                expr.end_location.row(),
+                                expr.end_location.column(),
+                            ),
+                            applied: false,
+                        });
+                    }
+                    checker.add_check(check);
+                }
+            }
+        }
+    }
+}

src/plugins/duplicate_exceptions.rs

@@ -0,0 +1,114 @@
+use std::collections::BTreeSet;
+
+use itertools::Itertools;
+use rustpython_ast::{Excepthandler, ExcepthandlerKind, Expr, ExprContext, ExprKind, Stmt};
+
+use crate::ast::helpers;
+use crate::ast::types::{CheckLocator, Range};
+use crate::autofix::fixer;
+use crate::check_ast::Checker;
+use crate::checks::{Check, CheckCode, CheckKind, Fix};
+use crate::code_gen::SourceGenerator;
+
+fn type_pattern(elts: Vec<&Expr>) -> Expr {
+    Expr::new(
+        Default::default(),
+        Default::default(),
+        ExprKind::Tuple {
+            elts: elts.into_iter().cloned().collect(),
+            ctx: ExprContext::Load,
+        },
+    )
+}
+
+pub fn duplicate_handler_exceptions(
+    checker: &mut Checker,
+    expr: &Expr,
+    elts: &Vec<Expr>,
+) -> BTreeSet<String> {
+    let mut seen: BTreeSet<String> = Default::default();
+    let mut duplicates: BTreeSet<String> = Default::default();
+    let mut unique_elts: Vec<&Expr> = Default::default();
+    for type_ in elts {
+        if let Some(name) = helpers::compose_call_path(type_) {
+            if seen.contains(&name) {
+                duplicates.insert(name);
+            } else {
+                seen.insert(name);
+                unique_elts.push(type_);
+            }
+        }
+    }
+
+    if checker.settings.enabled.contains(&CheckCode::B014) {
+        // TODO(charlie): Handle "BaseException" and redundant exception aliases.
+        if !duplicates.is_empty() {
+            let mut check = Check::new(
+                CheckKind::DuplicateHandlerException(
+                    duplicates.into_iter().sorted().collect::<Vec<String>>(),
+                ),
+                checker.locate_check(Range::from_located(expr)),
+            );
+            if matches!(checker.autofix, fixer::Mode::Generate | fixer::Mode::Apply) {
+                // TODO(charlie): If we have a single element, remove the tuple.
+                let mut generator = SourceGenerator::new();
+                if let Ok(()) = generator.unparse_expr(&type_pattern(unique_elts), 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);
+        }
+    }
+
+    seen
+}
+
+pub fn duplicate_exceptions(checker: &mut Checker, stmt: &Stmt, handlers: &[Excepthandler]) {
+    let mut seen: BTreeSet<String> = Default::default();
+    let mut duplicates: BTreeSet<String> = Default::default();
+    for handler in handlers {
+        match &handler.node {
+            ExcepthandlerKind::ExceptHandler { type_, .. } => {
+                if let Some(type_) = type_ {
+                    match &type_.node {
+                        ExprKind::Attribute { .. } | ExprKind::Name { .. } => {
+                            if let Some(name) = helpers::compose_call_path(type_) {
+                                if seen.contains(&name) {
+                                    duplicates.insert(name);
+                                } else {
+                                    seen.insert(name);
+                                }
+                            }
+                        }
+                        ExprKind::Tuple { elts, .. } => {
+                            for name in duplicate_handler_exceptions(checker, type_, elts) {
+                                if seen.contains(&name) {
+                                    duplicates.insert(name);
+                                } else {
+                                    seen.insert(name);
+                                }
+                            }
+                        }
+                        _ => {}
+                    }
+                }
+            }
+        }
+    }
+
+    if checker.settings.enabled.contains(&CheckCode::B025) {
+        for duplicate in duplicates.into_iter().sorted() {
+            checker.add_check(Check::new(
+                CheckKind::DuplicateTryBlockException(duplicate),
+                checker.locate_check(Range::from_located(stmt)),
+            ));
+        }
+    }
+}

src/plugins/if_tuple.rs

@@ -0,0 +1,11 @@
+use rustpython_ast::{Expr, Stmt};
+
+use crate::ast::checkers;
+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) = checkers::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::checkers;
+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) = checkers::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::{checkers, helpers};
+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 helpers::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) = checkers::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::checkers;
+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) =
+        checkers::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 +1,23 @@
+use rustpython_ast::Expr;
+
+use crate::ast::checkers;
+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) =
+        checkers::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);
+    }
+}

src/plugins/useless_metaclass_type.rs

@@ -0,0 +1,44 @@
+use log::error;
+use rustpython_ast::{Expr, Stmt};
+
+use crate::ast::checkers;
+use crate::ast::types::{CheckLocator, Range};
+use crate::autofix::{fixer, fixes};
+use crate::check_ast::Checker;
+
+pub fn useless_metaclass_type(
+    checker: &mut Checker,
+    stmt: &Stmt,
+    value: &Expr,
+    targets: &Vec<Expr>,
+) {
+    if let Some(mut check) = checkers::useless_metaclass_type(
+        targets,
+        value,
+        checker.locate_check(Range::from_located(stmt)),
+    ) {
+        if matches!(checker.autofix, fixer::Mode::Generate | fixer::Mode::Apply) {
+            let context = checker.binding_context();
+            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/useless_object_inheritance.rs

@@ -0,0 +1,29 @@
+use rustpython_ast::{Expr, Keyword, Stmt};
+
+use crate::ast::checkers;
+use crate::autofix::{fixer, fixes};
+use crate::check_ast::Checker;
+
+pub fn useless_object_inheritance(
+    checker: &mut Checker,
+    stmt: &Stmt,
+    name: &str,
+    bases: &[Expr],
+    keywords: &[Keyword],
+) {
+    let scope = checker.current_scope();
+    if let Some(mut check) = checkers::useless_object_inheritance(name, bases, scope) {
+        if matches!(checker.autofix, fixer::Mode::Generate | fixer::Mode::Apply) {
+            if let Some(fix) = fixes::remove_class_def_base(
+                &mut checker.locator,
+                &stmt.location,
+                check.location,
+                bases,
+                keywords,
+            ) {
+                check.amend(fix);
+            }
+        }
+        checker.add_check(check);
+    }
+}

src/printer.rs

@@ -21,6 +21,7 @@ struct ExpandedMessage<'a> {
     message: String,
     fixed: bool,
     location: Location,
+    end_location: Location,
     filename: &'a String,
 }
 
@@ -55,6 +56,7 @@ impl Printer {
                                 message: m.kind.body(),
                                 fixed: m.fixed,
                                 location: m.location,
+                                end_location: m.end_location,
                                 filename: &m.filename,
                             })
                             .collect::<Vec<_>>()

src/pyproject.rs

@@ -9,6 +9,7 @@ use serde::{Deserialize, Deserializer};
 
 use crate::checks::CheckCode;
 use crate::fs;
+use crate::settings::PythonVersion;
 
 pub fn load_config(pyproject: &Option<PathBuf>) -> Result<Config> {
     match pyproject {
@@ -29,11 +30,19 @@ pub fn load_config(pyproject: &Option<PathBuf>) -> Result<Config> {
 pub struct Config {
     pub line_length: Option<usize>,
     pub exclude: Option<Vec<String>>,
-    pub extend_exclude: Option<Vec<String>>,
+    #[serde(default)]
+    pub extend_exclude: Vec<String>,
     pub select: Option<Vec<CheckCode>>,
-    pub ignore: Option<Vec<CheckCode>>,
-    pub per_file_ignores: Option<Vec<StrCheckCodePair>>,
+    #[serde(default)]
+    pub extend_select: Vec<CheckCode>,
+    #[serde(default)]
+    pub ignore: Vec<CheckCode>,
+    #[serde(default)]
+    pub extend_ignore: Vec<CheckCode>,
+    #[serde(default)]
+    pub per_file_ignores: Vec<StrCheckCodePair>,
     pub dummy_variable_rgx: Option<String>,
+    pub target_version: Option<PythonVersion>,
 }
 
 #[derive(Clone, Debug, PartialEq, Eq)]
@@ -145,12 +154,13 @@ mod tests {
 
     use anyhow::Result;
 
-    use super::StrCheckCodePair;
     use crate::checks::CheckCode;
     use crate::pyproject::{
         find_project_root, find_pyproject_toml, parse_pyproject_toml, Config, PyProject, Tools,
     };
 
+    use super::StrCheckCodePair;
+
     #[test]
     fn deserialize() -> Result<()> {
         let pyproject: PyProject = toml::from_str(r#""#)?;
@@ -175,11 +185,14 @@ mod tests {
                 ruff: Some(Config {
                     line_length: None,
                     exclude: None,
-                    extend_exclude: None,
+                    extend_exclude: vec![],
                     select: None,
-                    ignore: None,
-                    per_file_ignores: None,
+                    extend_select: vec![],
+                    ignore: vec![],
+                    extend_ignore: vec![],
+                    per_file_ignores: vec![],
                     dummy_variable_rgx: None,
+                    target_version: None,
                 })
             })
         );
@@ -197,11 +210,14 @@ line-length = 79
                 ruff: Some(Config {
                     line_length: Some(79),
                     exclude: None,
-                    extend_exclude: None,
+                    extend_exclude: vec![],
                     select: None,
-                    ignore: None,
-                    per_file_ignores: None,
+                    extend_select: vec![],
+                    ignore: vec![],
+                    extend_ignore: vec![],
+                    per_file_ignores: vec![],
                     dummy_variable_rgx: None,
+                    target_version: None,
                 })
             })
         );
@@ -219,11 +235,14 @@ exclude = ["foo.py"]
                 ruff: Some(Config {
                     line_length: None,
                     exclude: Some(vec!["foo.py".to_string()]),
-                    extend_exclude: None,
+                    extend_exclude: vec![],
                     select: None,
-                    ignore: None,
-                    per_file_ignores: None,
+                    extend_select: vec![],
+                    ignore: vec![],
+                    extend_ignore: vec![],
+                    per_file_ignores: vec![],
                     dummy_variable_rgx: None,
+                    target_version: None,
                 })
             })
         );
@@ -241,11 +260,14 @@ select = ["E501"]
                 ruff: Some(Config {
                     line_length: None,
                     exclude: None,
-                    extend_exclude: None,
+                    extend_exclude: vec![],
                     select: Some(vec![CheckCode::E501]),
-                    ignore: None,
-                    per_file_ignores: None,
+                    extend_select: vec![],
+                    ignore: vec![],
+                    extend_ignore: vec![],
+                    per_file_ignores: vec![],
                     dummy_variable_rgx: None,
+                    target_version: None,
                 })
             })
         );
@@ -254,6 +276,7 @@ select = ["E501"]
             r#"
 [tool.black]
 [tool.ruff]
+extend-select = ["M001"]
 ignore = ["E501"]
 "#,
         )?;
@@ -263,11 +286,14 @@ ignore = ["E501"]
                 ruff: Some(Config {
                     line_length: None,
                     exclude: None,
-                    extend_exclude: None,
+                    extend_exclude: vec![],
                     select: None,
-                    ignore: Some(vec![CheckCode::E501]),
-                    per_file_ignores: None,
+                    extend_select: vec![CheckCode::M001],
+                    ignore: vec![CheckCode::E501],
+                    extend_ignore: vec![],
+                    per_file_ignores: vec![],
                     dummy_variable_rgx: None,
+                    target_version: None,
                 })
             })
         );
@@ -325,15 +351,18 @@ other-attribute = 1
             Config {
                 line_length: Some(88),
                 exclude: None,
-                extend_exclude: Some(vec![
+                extend_exclude: vec![
                     "excluded.py".to_string(),
                     "migrations".to_string(),
                     "directory/also_excluded.py".to_string(),
-                ]),
+                ],
                 select: None,
-                ignore: None,
-                per_file_ignores: None,
+                extend_select: vec![],
+                ignore: vec![],
+                extend_ignore: vec![],
+                per_file_ignores: vec![],
                 dummy_variable_rgx: None,
+                target_version: None,
             }
         );
 

src/python/typing.rs

@@ -7,6 +7,7 @@ static ANNOTATED_SUBSCRIPTS: Lazy<BTreeSet<&'static str>> = Lazy::new(|| {
         "AbstractAsyncContextManager",
         "AbstractContextManager",
         "AbstractSet",
+        // "Annotated",
         "AsyncContextManager",
         "AsyncGenerator",
         "AsyncIterable",
@@ -87,3 +88,14 @@ static ANNOTATED_SUBSCRIPTS: Lazy<BTreeSet<&'static str>> = Lazy::new(|| {
 pub fn is_annotated_subscript(name: &str) -> bool {
     ANNOTATED_SUBSCRIPTS.contains(name)
 }
+
+pub fn is_pep593_annotated_subscript(name: &str) -> bool {
+    name == "Annotated"
+}
+
+static PEP_585_BUILTINS: Lazy<BTreeSet<&'static str>> =
+    Lazy::new(|| BTreeSet::from(["Dict", "FrozenSet", "List", "Set", "Tuple", "Type"]));
+
+pub fn is_pep585_builtin(name: &str) -> bool {
+    PEP_585_BUILTINS.contains(name)
+}

src/settings.rs

@@ -1,16 +1,50 @@
 use std::collections::BTreeSet;
 use std::hash::{Hash, Hasher};
 use std::path::{Path, PathBuf};
+use std::str::FromStr;
 
 use anyhow::{anyhow, Result};
 use glob::Pattern;
 use once_cell::sync::Lazy;
 use regex::Regex;
+use serde::{Deserialize, Serialize};
 
 use crate::checks::{CheckCode, DEFAULT_CHECK_CODES};
 use crate::fs;
 use crate::pyproject::{load_config, StrCheckCodePair};
 
+#[derive(Clone, Debug, PartialOrd, PartialEq, Eq, Serialize, Deserialize)]
+pub enum PythonVersion {
+    Py33,
+    Py34,
+    Py35,
+    Py36,
+    Py37,
+    Py38,
+    Py39,
+    Py310,
+    Py311,
+}
+
+impl FromStr for PythonVersion {
+    type Err = anyhow::Error;
+
+    fn from_str(string: &str) -> Result<Self, Self::Err> {
+        match string {
+            "py33" => Ok(PythonVersion::Py33),
+            "py34" => Ok(PythonVersion::Py34),
+            "py35" => Ok(PythonVersion::Py35),
+            "py36" => Ok(PythonVersion::Py36),
+            "py37" => Ok(PythonVersion::Py37),
+            "py38" => Ok(PythonVersion::Py38),
+            "py39" => Ok(PythonVersion::Py39),
+            "py310" => Ok(PythonVersion::Py310),
+            "py311" => Ok(PythonVersion::Py311),
+            _ => Err(anyhow!("Unknown version: {}", string)),
+        }
+    }
+}
+
 #[derive(Debug, Clone, Hash)]
 pub enum FilePattern {
     Simple(&'static str),
@@ -51,56 +85,17 @@ impl PerFileIgnore {
 }
 
 #[derive(Debug)]
-pub struct Settings {
-    pub pyproject: Option<PathBuf>,
-    pub project_root: Option<PathBuf>,
-    pub line_length: usize,
+pub struct RawSettings {
+    pub dummy_variable_rgx: Regex,
     pub exclude: Vec<FilePattern>,
     pub extend_exclude: Vec<FilePattern>,
-    pub select: BTreeSet<CheckCode>,
+    pub extend_ignore: Vec<CheckCode>,
+    pub extend_select: Vec<CheckCode>,
+    pub ignore: Vec<CheckCode>,
+    pub line_length: usize,
     pub per_file_ignores: Vec<PerFileIgnore>,
-    pub dummy_variable_rgx: Regex,
-}
-
-impl Settings {
-    pub fn for_rule(check_code: CheckCode) -> Self {
-        Self {
-            pyproject: None,
-            project_root: None,
-            line_length: 88,
-            exclude: vec![],
-            extend_exclude: vec![],
-            select: BTreeSet::from([check_code]),
-            per_file_ignores: vec![],
-            dummy_variable_rgx: DEFAULT_DUMMY_VARIABLE_RGX.clone(),
-        }
-    }
-
-    pub fn for_rules(check_codes: Vec<CheckCode>) -> Self {
-        Self {
-            pyproject: None,
-            project_root: None,
-            line_length: 88,
-            exclude: vec![],
-            extend_exclude: vec![],
-            select: BTreeSet::from_iter(check_codes),
-            per_file_ignores: vec![],
-            dummy_variable_rgx: DEFAULT_DUMMY_VARIABLE_RGX.clone(),
-        }
-    }
-}
-
-impl Hash for Settings {
-    fn hash<H: Hasher>(&self, state: &mut H) {
-        self.line_length.hash(state);
-        self.dummy_variable_rgx.as_str().hash(state);
-        for value in self.select.iter() {
-            value.hash(state);
-        }
-        for value in self.per_file_ignores.iter() {
-            value.hash(state);
-        }
-    }
+    pub select: Vec<CheckCode>,
+    pub target_version: PythonVersion,
 }
 
 static DEFAULT_EXCLUDE: Lazy<Vec<FilePattern>> = Lazy::new(|| {
@@ -130,73 +125,117 @@ static DEFAULT_EXCLUDE: Lazy<Vec<FilePattern>> = Lazy::new(|| {
 static DEFAULT_DUMMY_VARIABLE_RGX: Lazy<Regex> =
     Lazy::new(|| Regex::new("^(_+|(_+[a-zA-Z0-9_]*[a-zA-Z0-9]+?))$").unwrap());
 
-impl Settings {
+impl RawSettings {
     pub fn from_pyproject(
-        pyproject: Option<PathBuf>,
-        project_root: Option<PathBuf>,
+        pyproject: &Option<PathBuf>,
+        project_root: &Option<PathBuf>,
     ) -> Result<Self> {
-        let config = load_config(&pyproject)?;
-        let mut settings = Settings {
-            line_length: config.line_length.unwrap_or(88),
-            exclude: config
-                .exclude
-                .map(|paths| {
-                    paths
-                        .iter()
-                        .map(|path| FilePattern::from_user(path, &project_root))
-                        .collect()
-                })
-                .unwrap_or_else(|| DEFAULT_EXCLUDE.clone()),
-            extend_exclude: config
-                .extend_exclude
-                .map(|paths| {
-                    paths
-                        .iter()
-                        .map(|path| FilePattern::from_user(path, &project_root))
-                        .collect()
-                })
-                .unwrap_or_default(),
-            select: if let Some(select) = config.select {
-                BTreeSet::from_iter(select)
-            } else {
-                BTreeSet::from_iter(DEFAULT_CHECK_CODES)
-            },
-            per_file_ignores: config
-                .per_file_ignores
-                .map(|ignore_strings| {
-                    ignore_strings
-                        .into_iter()
-                        .map(|pair| PerFileIgnore::new(pair, &project_root))
-                        .collect()
-                })
-                .unwrap_or_default(),
+        let config = load_config(pyproject)?;
+        Ok(RawSettings {
             dummy_variable_rgx: match config.dummy_variable_rgx {
                 Some(pattern) => Regex::new(&pattern)
                     .map_err(|e| anyhow!("Invalid dummy-variable-rgx value: {e}"))?,
                 None => DEFAULT_DUMMY_VARIABLE_RGX.clone(),
             },
-            pyproject,
-            project_root,
-        };
-        if let Some(ignore) = &config.ignore {
-            settings.ignore(ignore);
+            target_version: config.target_version.unwrap_or(PythonVersion::Py310),
+            exclude: config
+                .exclude
+                .map(|paths| {
+                    paths
+                        .iter()
+                        .map(|path| FilePattern::from_user(path, project_root))
+                        .collect()
+                })
+                .unwrap_or_else(|| DEFAULT_EXCLUDE.clone()),
+            extend_exclude: config
+                .extend_exclude
+                .iter()
+                .map(|path| FilePattern::from_user(path, project_root))
+                .collect(),
+            extend_ignore: config.extend_ignore,
+            select: config
+                .select
+                .unwrap_or_else(|| DEFAULT_CHECK_CODES.to_vec()),
+            extend_select: config.extend_select,
+            ignore: config.ignore,
+            line_length: config.line_length.unwrap_or(88),
+            per_file_ignores: config
+                .per_file_ignores
+                .into_iter()
+                .map(|pair| PerFileIgnore::new(pair, project_root))
+                .collect(),
+        })
+    }
+}
+
+#[derive(Debug)]
+pub struct Settings {
+    pub dummy_variable_rgx: Regex,
+    pub enabled: BTreeSet<CheckCode>,
+    pub exclude: Vec<FilePattern>,
+    pub extend_exclude: Vec<FilePattern>,
+    pub line_length: usize,
+    pub per_file_ignores: Vec<PerFileIgnore>,
+    pub target_version: PythonVersion,
+}
+
+impl Settings {
+    pub fn from_raw(settings: RawSettings) -> Self {
+        // Materialize the set of enabled CheckCodes.
+        let mut enabled: BTreeSet<CheckCode> = BTreeSet::new();
+        enabled.extend(settings.select);
+        enabled.extend(settings.extend_select);
+        for code in &settings.ignore {
+            enabled.remove(code);
         }
-        Ok(settings)
-    }
-
-    pub fn clear(&mut self) {
-        self.select.clear();
-    }
-
-    pub fn select(&mut self, codes: Vec<CheckCode>) {
-        for code in codes {
-            self.select.insert(code);
+        for code in &settings.extend_ignore {
+            enabled.remove(code);
+        }
+        Self {
+            dummy_variable_rgx: settings.dummy_variable_rgx,
+            enabled,
+            exclude: settings.exclude,
+            extend_exclude: settings.extend_exclude,
+            line_length: settings.line_length,
+            per_file_ignores: settings.per_file_ignores,
+            target_version: PythonVersion::Py310,
         }
     }
 
-    pub fn ignore(&mut self, codes: &[CheckCode]) {
-        for code in codes {
-            self.select.remove(code);
+    pub fn for_rule(check_code: CheckCode) -> Self {
+        Self {
+            dummy_variable_rgx: DEFAULT_DUMMY_VARIABLE_RGX.clone(),
+            enabled: BTreeSet::from([check_code]),
+            exclude: vec![],
+            extend_exclude: vec![],
+            line_length: 88,
+            per_file_ignores: vec![],
+            target_version: PythonVersion::Py310,
+        }
+    }
+
+    pub fn for_rules(check_codes: Vec<CheckCode>) -> Self {
+        Self {
+            dummy_variable_rgx: DEFAULT_DUMMY_VARIABLE_RGX.clone(),
+            enabled: BTreeSet::from_iter(check_codes),
+            exclude: vec![],
+            extend_exclude: vec![],
+            line_length: 88,
+            per_file_ignores: vec![],
+            target_version: PythonVersion::Py310,
+        }
+    }
+}
+
+impl Hash for Settings {
+    fn hash<H: Hasher>(&self, state: &mut H) {
+        self.line_length.hash(state);
+        self.dummy_variable_rgx.as_str().hash(state);
+        for value in self.enabled.iter() {
+            value.hash(state);
+        }
+        for value in self.per_file_ignores.iter() {
+            value.hash(state);
         }
     }
 }
@@ -227,22 +266,28 @@ impl Exclusion {
 /// Struct to render user-facing Settings.
 #[derive(Debug)]
 pub struct CurrentSettings {
-    pub pyproject: Option<PathBuf>,
-    pub project_root: Option<PathBuf>,
-    pub line_length: usize,
+    pub dummy_variable_rgx: Regex,
     pub exclude: Vec<Exclusion>,
     pub extend_exclude: Vec<Exclusion>,
-    pub select: BTreeSet<CheckCode>,
+    pub extend_ignore: Vec<CheckCode>,
+    pub extend_select: Vec<CheckCode>,
+    pub ignore: Vec<CheckCode>,
+    pub line_length: usize,
     pub per_file_ignores: Vec<PerFileIgnore>,
-    pub dummy_variable_rgx: Regex,
+    pub select: Vec<CheckCode>,
+    pub target_version: PythonVersion,
+    pub project_root: Option<PathBuf>,
+    pub pyproject: Option<PathBuf>,
 }
 
 impl CurrentSettings {
-    pub fn from_settings(settings: Settings) -> Self {
+    pub fn from_settings(
+        settings: RawSettings,
+        project_root: Option<PathBuf>,
+        pyproject: Option<PathBuf>,
+    ) -> Self {
         Self {
-            pyproject: settings.pyproject,
-            project_root: settings.project_root,
-            line_length: settings.line_length,
+            dummy_variable_rgx: settings.dummy_variable_rgx,
             exclude: settings
                 .exclude
                 .into_iter()
@@ -253,9 +298,15 @@ impl CurrentSettings {
                 .into_iter()
                 .map(Exclusion::from_file_pattern)
                 .collect(),
-            select: settings.select,
+            extend_ignore: settings.extend_ignore,
+            extend_select: settings.extend_select,
+            ignore: settings.ignore,
+            line_length: settings.line_length,
             per_file_ignores: settings.per_file_ignores,
-            dummy_variable_rgx: settings.dummy_variable_rgx,
+            select: settings.select,
+            target_version: settings.target_version,
+            project_root,
+            pyproject,
         }
     }
 }

src/snapshots/ruff__linter__tests__a001.snap

@@ -0,0 +1,167 @@
+---
+source: src/linter.rs
+expression: checks
+---
+- kind:
+    BuiltinVariableShadowing: sum
+  location:
+    row: 1
+    column: 1
+  end_location:
+    row: 1
+    column: 19
+  fix: ~
+- kind:
+    BuiltinVariableShadowing: int
+  location:
+    row: 2
+    column: 1
+  end_location:
+    row: 2
+    column: 30
+  fix: ~
+- kind:
+    BuiltinVariableShadowing: print
+  location:
+    row: 4
+    column: 1
+  end_location:
+    row: 4
+    column: 6
+  fix: ~
+- kind:
+    BuiltinVariableShadowing: copyright
+  location:
+    row: 5
+    column: 1
+  end_location:
+    row: 5
+    column: 10
+  fix: ~
+- kind:
+    BuiltinVariableShadowing: complex
+  location:
+    row: 6
+    column: 2
+  end_location:
+    row: 6
+    column: 14
+  fix: ~
+- kind:
+    BuiltinVariableShadowing: float
+  location:
+    row: 7
+    column: 1
+  end_location:
+    row: 7
+    column: 6
+  fix: ~
+- kind:
+    BuiltinVariableShadowing: object
+  location:
+    row: 7
+    column: 9
+  end_location:
+    row: 7
+    column: 15
+  fix: ~
+- kind:
+    BuiltinVariableShadowing: min
+  location:
+    row: 8
+    column: 1
+  end_location:
+    row: 8
+    column: 4
+  fix: ~
+- kind:
+    BuiltinVariableShadowing: max
+  location:
+    row: 8
+    column: 6
+  end_location:
+    row: 8
+    column: 9
+  fix: ~
+- kind:
+    BuiltinVariableShadowing: bytes
+  location:
+    row: 10
+    column: 1
+  end_location:
+    row: 13
+    column: 1
+  fix: ~
+- kind:
+    BuiltinVariableShadowing: slice
+  location:
+    row: 13
+    column: 1
+  end_location:
+    row: 16
+    column: 1
+  fix: ~
+- kind:
+    BuiltinVariableShadowing: ValueError
+  location:
+    row: 18
+    column: 1
+  end_location:
+    row: 21
+    column: 1
+  fix: ~
+- kind:
+    BuiltinVariableShadowing: memoryview
+  location:
+    row: 21
+    column: 5
+  end_location:
+    row: 21
+    column: 15
+  fix: ~
+- kind:
+    BuiltinVariableShadowing: bytearray
+  location:
+    row: 21
+    column: 18
+  end_location:
+    row: 21
+    column: 27
+  fix: ~
+- kind:
+    BuiltinVariableShadowing: str
+  location:
+    row: 24
+    column: 22
+  end_location:
+    row: 24
+    column: 25
+  fix: ~
+- kind:
+    BuiltinVariableShadowing: all
+  location:
+    row: 24
+    column: 45
+  end_location:
+    row: 24
+    column: 48
+  fix: ~
+- kind:
+    BuiltinVariableShadowing: any
+  location:
+    row: 24
+    column: 50
+  end_location:
+    row: 24
+    column: 53
+  fix: ~
+- kind:
+    BuiltinVariableShadowing: sum
+  location:
+    row: 27
+    column: 8
+  end_location:
+    row: 27
+    column: 11
+  fix: ~
+

src/snapshots/ruff__linter__tests__a002.snap

@@ -0,0 +1,68 @@
+---
+source: src/linter.rs
+expression: checks
+---
+- kind:
+    BuiltinArgumentShadowing: str
+  location:
+    row: 1
+    column: 11
+  end_location:
+    row: 1
+    column: 14
+  fix: ~
+- kind:
+    BuiltinArgumentShadowing: type
+  location:
+    row: 1
+    column: 19
+  end_location:
+    row: 1
+    column: 23
+  fix: ~
+- kind:
+    BuiltinArgumentShadowing: complex
+  location:
+    row: 1
+    column: 26
+  end_location:
+    row: 1
+    column: 33
+  fix: ~
+- kind:
+    BuiltinArgumentShadowing: Exception
+  location:
+    row: 1
+    column: 35
+  end_location:
+    row: 1
+    column: 44
+  fix: ~
+- kind:
+    BuiltinArgumentShadowing: getattr
+  location:
+    row: 1
+    column: 48
+  end_location:
+    row: 1
+    column: 55
+  fix: ~
+- kind:
+    BuiltinArgumentShadowing: bytes
+  location:
+    row: 5
+    column: 17
+  end_location:
+    row: 5
+    column: 22
+  fix: ~
+- kind:
+    BuiltinArgumentShadowing: float
+  location:
+    row: 9
+    column: 16
+  end_location:
+    row: 9
+    column: 21
+  fix: ~
+

src/snapshots/ruff__linter__tests__a003.snap

@@ -0,0 +1,23 @@
+---
+source: src/linter.rs
+expression: checks
+---
+- kind:
+    BuiltinAttributeShadowing: ImportError
+  location:
+    row: 2
+    column: 5
+  end_location:
+    row: 2
+    column: 16
+  fix: ~
+- kind:
+    BuiltinAttributeShadowing: str
+  location:
+    row: 7
+    column: 5
+  end_location:
+    row: 9
+    column: 1
+  fix: ~
+

src/snapshots/ruff__linter__tests__b011.snap

@@ -0,0 +1,37 @@
+---
+source: src/linter.rs
+expression: checks
+---
+- kind: DoNotAssertFalse
+  location:
+    row: 8
+    column: 8
+  end_location:
+    row: 8
+    column: 13
+  fix:
+    content: raise AssertionError()
+    location:
+      row: 8
+      column: 1
+    end_location:
+      row: 8
+      column: 13
+    applied: false
+- kind: DoNotAssertFalse
+  location:
+    row: 10
+    column: 8
+  end_location:
+    row: 10
+    column: 13
+  fix:
+    content: "raise AssertionError(\"message\")"
+    location:
+      row: 10
+      column: 1
+    end_location:
+      row: 10
+      column: 24
+    applied: false
+

src/snapshots/ruff__linter__tests__b014.snap

@@ -0,0 +1,59 @@
+---
+source: src/linter.rs
+expression: checks
+---
+- kind:
+    DuplicateHandlerException:
+      - OSError
+  location:
+    row: 17
+    column: 9
+  end_location:
+    row: 17
+    column: 25
+  fix:
+    content: "OSError,"
+    location:
+      row: 17
+      column: 9
+    end_location:
+      row: 17
+      column: 25
+    applied: false
+- kind:
+    DuplicateHandlerException:
+      - MyError
+  location:
+    row: 28
+    column: 9
+  end_location:
+    row: 28
+    column: 25
+  fix:
+    content: "MyError,"
+    location:
+      row: 28
+      column: 9
+    end_location:
+      row: 28
+      column: 25
+    applied: false
+- kind:
+    DuplicateHandlerException:
+      - re.error
+  location:
+    row: 49
+    column: 9
+  end_location:
+    row: 49
+    column: 27
+  fix:
+    content: "re.error,"
+    location:
+      row: 49
+      column: 9
+    end_location:
+      row: 49
+      column: 27
+    applied: false
+

src/snapshots/ruff__linter__tests__b025.snap

@@ -0,0 +1,41 @@
+---
+source: src/linter.rs
+expression: checks
+---
+- kind:
+    DuplicateTryBlockException: ValueError
+  location:
+    row: 15
+    column: 1
+  end_location:
+    row: 22
+    column: 1
+  fix: ~
+- kind:
+    DuplicateTryBlockException: pickle.PickleError
+  location:
+    row: 22
+    column: 1
+  end_location:
+    row: 31
+    column: 1
+  fix: ~
+- kind:
+    DuplicateTryBlockException: TypeError
+  location:
+    row: 31
+    column: 1
+  end_location:
+    row: 39
+    column: 1
+  fix: ~
+- kind:
+    DuplicateTryBlockException: ValueError
+  location:
+    row: 31
+    column: 1
+  end_location:
+    row: 39
+    column: 1
+  fix: ~
+

src/snapshots/ruff__linter__tests__c400.snap

@@ -0,0 +1,13 @@
+---
+source: src/linter.rs
+expression: checks
+---
+- kind: UnnecessaryGeneratorList
+  location:
+    row: 1
+    column: 5
+  end_location:
+    row: 1
+    column: 30
+  fix: ~
+