Bump version to 0.0.39

Remove erroneous test dir
Improve exclusion syntax to match exact files (#209 )
2022-09-15 21:41:14 -04:00 · 2022-09-15 21:41:00 -04:00 · 2022-09-15 21:40:49 -04:00 · 2022-09-15 20:40:06 -04:00 · 2022-09-15 20:39:39 -04:00 · 2022-09-15 16:05:29 -04:00
102 changed files with 5460 additions and 1832 deletions
--- a/.github/workflows/release.yaml
+++ b/.github/workflows/release.yaml
@@ -16,7 +16,7 @@ env:
  PYTHON_VERSION: "3.7" # to build abi3 wheels

 jobs:
-  macos:
+  macos-x86_64:
    runs-on: macos-latest
    steps:
      - uses: actions/checkout@v3
@@ -39,6 +39,25 @@ jobs:
      - name: Install built wheel - x86_64
        run: |
          pip install dist/${{ env.PACKAGE_NAME }}-*.whl --force-reinstall
+      - name: Upload wheels
+        uses: actions/upload-artifact@v2
+        with:
+          name: wheels
+          path: dist
+  macos-universal:
+    runs-on: macos-latest
+    steps:
+      - uses: actions/checkout@v3
+      - uses: actions/setup-python@v4
+        with:
+          python-version: ${{ env.PYTHON_VERSION }}
+          architecture: x64
+      - name: Install Rust toolchain
+        uses: actions-rs/toolchain@v1
+        with:
+          toolchain: stable
+          profile: minimal
+          default: true
      - name: Build wheels - universal2
        uses: messense/maturin-action@v1
        with:
@@ -261,7 +280,8 @@ jobs:
    name: Release
    runs-on: ubuntu-latest
    needs:
-      - macos
+      - macos-universal
+      - macos-x86_64
      - windows
      - linux
      - linux-cross
--- a/.pre-commit-config.yaml
+++ b/.pre-commit-config.yaml
@@ -1,5 +1,5 @@
 repos:
  - repo: https://github.com/charliermarsh/ruff
-    rev: v0.0.29
+    rev: v0.0.39
    hooks:
      - id: lint
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -458,6 +458,19 @@ dependencies = [
 "cache-padded",
 ]

+[[package]]
+name = "console"
+version = "0.15.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "89eab4d20ce20cea182308bca13088fecea9c05f6776cf287205d41a0ed3c847"
+dependencies = [
+ "encode_unicode",
+ "libc",
+ "once_cell",
+ "terminal_size",
+ "winapi 0.3.9",
+]
+
 [[package]]
 name = "core-foundation"
 version = "0.9.3"
@@ -652,6 +665,12 @@ dependencies = [
 "log",
 ]

+[[package]]
+name = "encode_unicode"
+version = "0.3.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a357d28ed41a50f9c765dbfe56cbc04a64e53e5fc58ba79fbc34c10ef3df831f"
+
 [[package]]
 name = "event-listener"
 version = "2.5.3"
@@ -1011,6 +1030,20 @@ dependencies = [
 "libc",
 ]

+[[package]]
+name = "insta"
+version = "1.19.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "fc61e98be01e89296f3343a878e9f8ca75a494cb5aaf29df65ef55734aeb85f5"
+dependencies = [
+ "console",
+ "linked-hash-map",
+ "once_cell",
+ "serde",
+ "similar",
+ "yaml-rust",
+]
+
 [[package]]
 name = "instant"
 version = "0.1.12"
@@ -1122,6 +1155,12 @@ version = "0.2.127"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "505e71a4706fa491e9b1b55f51b95d4037d0821ee40131190475f692b35b009b"

+[[package]]
+name = "linked-hash-map"
+version = "0.5.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0717cef1bc8b636c6e1c1bbdefc09e6322da8a9321966e8928ef80d20f7f770f"
+
 [[package]]
 name = "lock_api"
 version = "0.4.7"
@@ -1393,6 +1432,24 @@ dependencies = [
 "windows-sys",
 ]

+[[package]]
+name = "path-absolutize"
+version = "3.0.13"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d3de4b40bd9736640f14c438304c09538159802388febb02c8abaae0846c1f13"
+dependencies = [
+ "path-dedot",
+]
+
+[[package]]
+name = "path-dedot"
+version = "3.0.17"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d611d5291372b3738a34ebf0d1f849e58b1dcc1101032f76a346eaa1f8ddbb5b"
+dependencies = [
+ "once_cell",
+]
+
 [[package]]
 name = "percent-encoding"
 version = "2.1.0"
@@ -1744,7 +1801,7 @@ dependencies = [

 [[package]]
 name = "ruff"
-version = "0.0.29"
+version = "0.0.39"
 dependencies = [
 "anyhow",
 "bincode",
@@ -1758,10 +1815,12 @@ dependencies = [
 "fern",
 "filetime",
 "glob",
+ "insta",
 "itertools",
 "log",
 "notify",
 "once_cell",
+ "path-absolutize",
 "rayon",
 "regex",
 "rustpython-parser",
@@ -1787,7 +1846,7 @@ dependencies = [
 [[package]]
 name = "rustpython-ast"
 version = "0.1.0"
-source = "git+https://github.com/charliermarsh/RustPython.git?rev=8cc3d23ddaa6339bf56608adaeefabff3ad329e7#8cc3d23ddaa6339bf56608adaeefabff3ad329e7"
+source = "git+https://github.com/charliermarsh/RustPython.git?rev=7d21c6923a506e79cc041708d83cef925efd33f4#7d21c6923a506e79cc041708d83cef925efd33f4"
 dependencies = [
 "num-bigint",
 "rustpython-compiler-core",
@@ -1796,7 +1855,7 @@ dependencies = [
 [[package]]
 name = "rustpython-compiler-core"
 version = "0.1.2"
-source = "git+https://github.com/charliermarsh/RustPython.git?rev=8cc3d23ddaa6339bf56608adaeefabff3ad329e7#8cc3d23ddaa6339bf56608adaeefabff3ad329e7"
+source = "git+https://github.com/charliermarsh/RustPython.git?rev=7d21c6923a506e79cc041708d83cef925efd33f4#7d21c6923a506e79cc041708d83cef925efd33f4"
 dependencies = [
 "bincode",
 "bitflags",
@@ -1813,7 +1872,7 @@ dependencies = [
 [[package]]
 name = "rustpython-parser"
 version = "0.1.2"
-source = "git+https://github.com/charliermarsh/RustPython.git?rev=8cc3d23ddaa6339bf56608adaeefabff3ad329e7#8cc3d23ddaa6339bf56608adaeefabff3ad329e7"
+source = "git+https://github.com/charliermarsh/RustPython.git?rev=7d21c6923a506e79cc041708d83cef925efd33f4#7d21c6923a506e79cc041708d83cef925efd33f4"
 dependencies = [
 "ahash",
 "anyhow",
@@ -1977,6 +2036,12 @@ dependencies = [
 "libc",
 ]

+[[package]]
+name = "similar"
+version = "2.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "62ac7f900db32bf3fd12e0117dd3dc4da74bc52ebaac97f39668446d89694803"
+
 [[package]]
 name = "siphasher"
 version = "0.3.10"
@@ -2099,6 +2164,16 @@ dependencies = [
 "winapi-util",
 ]

+[[package]]
+name = "terminal_size"
+version = "0.1.17"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "633c1a546cee861a1a6d0dc69ebeca693bf4296661ba7852b9d21d159e0506df"
+dependencies = [
+ "libc",
+ "winapi 0.3.9",
+]
+
 [[package]]
 name = "terminfo"
 version = "0.7.3"
@@ -2594,3 +2669,12 @@ dependencies = [
 "winapi 0.2.8",
 "winapi-build",
 ]
+
+[[package]]
+name = "yaml-rust"
+version = "0.4.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "56c1936c4cc7a1c9ab21a1ebb602eb942ba868cbd44a99cb7cdc5892335e1c85"
+dependencies = [
+ "linked-hash-map",
+]
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "ruff"
-version = "0.0.29"
+version = "0.0.39"
 edition = "2021"

 [lib]
@@ -18,20 +18,24 @@ common-path = { version = "1.0.0" }
 dirs = { version = "4.0.0" }
 fern = { version = "0.6.1" }
 filetime = { version = "0.2.17" }
-glob = { version = "0.3.0" }
+glob = "0.3.0"
 itertools = "0.10.3"
 log = { version = "0.4.17" }
 notify = { version = "4.0.17" }
 once_cell = { version = "1.13.1" }
+path-absolutize = "3.0.13"
 rayon = { version = "1.5.3" }
 regex = { version = "1.6.0" }
-rustpython-parser = { features = ["lalrpop"], git = "https://github.com/charliermarsh/RustPython.git", rev = "8cc3d23ddaa6339bf56608adaeefabff3ad329e7" }
+rustpython-parser = { features = ["lalrpop"], git = "https://github.com/charliermarsh/RustPython.git", rev = "7d21c6923a506e79cc041708d83cef925efd33f4" }
 serde = { version = "1.0.143", features = ["derive"] }
 serde_json = { version = "1.0.83" }
 toml = { version = "0.5.9" }
 update-informer = { version = "0.5.0", default_features = false, features = ["pypi"], optional = true }
 walkdir = { version = "2.3.2" }

+[dev-dependencies]
+insta = { version = "1.19.1", features = ["yaml"] }
+
 [features]
 default = ["update-informer"]
 update-informer = ["dep:update-informer"]
@@ -41,3 +45,9 @@ panic = "abort"
 lto = "thin"
 codegen-units = 1
 opt-level = 3
+
+[profile.dev.package.insta]
+opt-level = 3
+
+[profile.dev.package.similar]
+opt-level = 3
--- a/README.md
+++ b/README.md
@@ -57,7 +57,7 @@ ruff also works with [Pre-Commit](https://pre-commit.com) (requires Cargo on sys
 ```yaml
 repos:
 - repo: https://github.com/charliermarsh/ruff
-  rev: v0.0.29
+  rev: v0.0.39
  hooks:
    - id: lint
 ```
@@ -86,7 +86,7 @@ ruff path/to/code/ --select F401 F403
 See `ruff --help` for more:

 ```shell
-ruff (v0.0.29)
+ruff (v0.0.39)
 An extremely fast Python linter.

 USAGE:
@@ -96,18 +96,42 @@ ARGS:
    <FILES>...

 OPTIONS:
-    -e, --exit-zero             Exit with status code "0", even upon detecting errors
-    -f, --fix                   Attempt to automatically fix lint errors
-    -h, --help                  Print help information
-        --ignore <IGNORE>...    Comma-separated list of error codes to ignore
-    -n, --no-cache              Disable cache reads
-    -q, --quiet                 Disable all logging (but still exit with status code "1" upon
-                                detecting errors)
-        --select <SELECT>...    Comma-separated list of error codes to enable
-    -v, --verbose               Enable verbose logging
-    -w, --watch                 Run in watch mode by re-running whenever files change
+    -e, --exit-zero
+            Exit with status code "0", even upon detecting errors
+        --exclude <EXCLUDE>...
+            List of paths, used to exclude files and/or directories from checks
+        --extend-exclude <EXTEND_EXCLUDE>...
+            Like --exclude, but adds additional files and directories on top of the excluded ones
+    -f, --fix
+            Attempt to automatically fix lint errors
+        --format <FORMAT>
+            Output serialization format for error messages [default: text] [possible values: text,
+            json]
+    -h, --help
+            Print help information
+        --ignore <IGNORE>...
+            List of error codes to ignore
+    -n, --no-cache
+            Disable cache reads
+    -q, --quiet
+            Disable all logging (but still exit with status code "1" upon detecting errors)
+        --select <SELECT>...
+            List of error codes to enable
+    -v, --verbose
+            Enable verbose logging
+    -w, --watch
+            Run in watch mode by re-running whenever files change
 ```

+Exclusions are based on globs, and can be either:
+
+- Single-path patterns, like `.mypy_cache` (to exclude any directory named `.mypy_cache` in the
+  tree), `foo.py` (to exclude any file named `foo.py`), or `foo_*.py` (to exclude any file matching
+  `foo_*.py` ).
+- Relative patterns, like `./directory/foo.py` (to exclude that specific file) or `./directory/*.py`
+  (to exclude any Python files in `./directory`). Note that these paths are relative to the
+  directory from which you execute `ruff`, and _not_ the directory of the `pyproject.toml`.
+
 ### Compatibility with Black

 ruff is intended to be compatible with [Black](https://github.com/psf/black), and should be
@@ -116,26 +140,66 @@ compatible out-of-the-box as long as the `line-length` setting is consistent bet
 As a project, ruff is designed to be used alongside Black and, as such, will defer implementing
 lint rules that are obviated by Black (e.g., stylistic rules).

+### Parity with Flake8
+
+ruff's goal is to achieve feature-parity with Flake8 when used (1) without any plugins,
+(2) alongside Black, and (3) on Python 3 code. (Using Black obviates the need for many of Flake8's
+stylistic checks; limiting to Python 3 obviates the need for certain compatibility checks.)
+
+Under those conditions, Flake8 implements about 60 rules, give or take. At time of writing, ruff
+implements 42 rules. (Note that these 42 rules likely cover a disproportionate share of errors:
+unused imports, undefined variables, etc.)
+
+The unimplemented rules are tracked in #170, and include:
+
+- 14 rules related to string `.format` calls.
+- 4 logical rules.
+- 1 rule related to parsing.
+
+Beyond rule-set parity, ruff suffers from the following limitations vis-à-vis Flake8:
+
+1. Flake8 supports a wider range of `noqa` patterns, such as per-file ignores defined in `.flake8`.
+2. Flake8 has a plugin architecture and supports writing custom lint rules.
+3. ruff does not yet support parenthesized context managers.
+
 ## Rules

 | Code | Name | Message |
 | ---- | ----- | ------- |
 | E402 | ModuleImportNotAtTopOfFile | Module level import not at top of file |
-| E501 | LineTooLong | Line too long |
+| 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 | No such file or directory: `...` |
+| E999 | SyntaxError | SyntaxError: ... |
 | F401 | UnusedImport | `...` imported but unused |
-| F403 | ImportStarUsage | Unable to detect undefined names |
+| F403 | ImportStarUsage | `from ... import *` used; unable to detect undefined names |
+| F404 | LateFutureImport | from __future__ imports must occur at the beginning of the file |
+| 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 |
@@ -177,31 +241,31 @@ git clone --branch 3.10 https://github.com/python/cpython.git resources/test/cpy
 Add this `pyproject.toml` to the CPython directory:

 ```toml
-[tool.linter]
+[tool.ruff]
 line-length = 88
 exclude = [
-    "Lib/lib2to3/tests/data/bom.py",
-    "Lib/lib2to3/tests/data/crlf.py",
-    "Lib/lib2to3/tests/data/different_encoding.py",
-    "Lib/lib2to3/tests/data/false_encoding.py",
-    "Lib/lib2to3/tests/data/py2_test_grammar.py",
-    "Lib/test/bad_coding2.py",
-    "Lib/test/badsyntax_3131.py",
-    "Lib/test/badsyntax_pep3120.py",
-    "Lib/test/encoded_modules/module_iso_8859_1.py",
-    "Lib/test/encoded_modules/module_koi8_r.py",
-    "Lib/test/test_fstring.py",
-    "Lib/test/test_grammar.py",
-    "Lib/test/test_importlib/test_util.py",
-    "Lib/test/test_named_expressions.py",
-    "Lib/test/test_patma.py",
-    "Lib/test/test_source_encoding.py",
-    "Tools/c-analyzer/c_parser/parser/_delim.py",
-    "Tools/i18n/pygettext.py",
-    "Tools/test2to3/maintest.py",
-    "Tools/test2to3/setup.py",
-    "Tools/test2to3/test/test_foo.py",
-    "Tools/test2to3/test2to3/hello.py",
+    "./resources/test/cpython/Lib/lib2to3/tests/data/bom.py",
+    "./resources/test/cpython/Lib/lib2to3/tests/data/crlf.py",
+    "./resources/test/cpython/Lib/lib2to3/tests/data/different_encoding.py",
+    "./resources/test/cpython/Lib/lib2to3/tests/data/false_encoding.py",
+    "./resources/test/cpython/Lib/lib2to3/tests/data/py2_test_grammar.py",
+    "./resources/test/cpython/Lib/test/bad_coding2.py",
+    "./resources/test/cpython/Lib/test/badsyntax_3131.py",
+    "./resources/test/cpython/Lib/test/badsyntax_pep3120.py",
+    "./resources/test/cpython/Lib/test/encoded_modules/module_iso_8859_1.py",
+    "./resources/test/cpython/Lib/test/encoded_modules/module_koi8_r.py",
+    "./resources/test/cpython/Lib/test/test_fstring.py",
+    "./resources/test/cpython/Lib/test/test_grammar.py",
+    "./resources/test/cpython/Lib/test/test_importlib/test_util.py",
+    "./resources/test/cpython/Lib/test/test_named_expressions.py",
+    "./resources/test/cpython/Lib/test/test_patma.py",
+    "./resources/test/cpython/Lib/test/test_source_encoding.py",
+    "./resources/test/cpython/Tools/c-analyzer/c_parser/parser/_delim.py",
+    "./resources/test/cpython/Tools/i18n/pygettext.py",
+    "./resources/test/cpython/Tools/test2to3/maintest.py",
+    "./resources/test/cpython/Tools/test2to3/setup.py",
+    "./resources/test/cpython/Tools/test2to3/test/test_foo.py",
+    "./resources/test/cpython/Tools/test2to3/test2to3/hello.py",
 ]
 ```

--- a/examples/generate_rules_table.rs
+++ b/examples/generate_rules_table.rs
@@ -3,23 +3,41 @@ use ruff::checks::{CheckKind, RejectedCmpop};

 fn main() {
    let mut check_kinds: Vec<CheckKind> = vec![
+        CheckKind::AmbiguousClassName("...".to_string()),
+        CheckKind::AmbiguousFunctionName("...".to_string()),
+        CheckKind::AmbiguousVariableName("...".to_string()),
        CheckKind::AssertTuple,
+        CheckKind::BreakOutsideLoop,
+        CheckKind::ContinueOutsideLoop,
        CheckKind::DefaultExceptNotLast,
        CheckKind::DoNotAssignLambda,
+        CheckKind::DoNotUseBareExcept,
        CheckKind::DuplicateArgumentName,
        CheckKind::FStringMissingPlaceholders,
+        CheckKind::ForwardAnnotationSyntaxError("...".to_string()),
+        CheckKind::FutureFeatureNotDefined("...".to_string()),
        CheckKind::IOError("...".to_string()),
        CheckKind::IfTuple,
-        CheckKind::ImportStarUsage,
-        CheckKind::LineTooLong,
+        CheckKind::ImportStarNotPermitted("...".to_string()),
+        CheckKind::ImportStarUsage("...".to_string()),
+        CheckKind::InvalidPrintSyntax,
+        CheckKind::IsLiteral,
+        CheckKind::LateFutureImport,
+        CheckKind::LineTooLong(89, 88),
        CheckKind::ModuleImportNotAtTopOfFile,
+        CheckKind::MultiValueRepeatedKeyLiteral,
+        CheckKind::MultiValueRepeatedKeyVariable("...".to_string()),
        CheckKind::NoAssertEquals,
        CheckKind::NoneComparison(RejectedCmpop::Eq),
        CheckKind::NotInTest,
        CheckKind::NotIsTest,
        CheckKind::RaiseNotImplemented,
        CheckKind::ReturnOutsideFunction,
+        CheckKind::SyntaxError("...".to_string()),
+        CheckKind::TooManyExpressionsInStarredAssignment,
        CheckKind::TrueFalseComparison(true, RejectedCmpop::Eq),
+        CheckKind::TwoStarredExpressions,
+        CheckKind::TypeComparison,
        CheckKind::UndefinedExport("...".to_string()),
        CheckKind::UndefinedLocal("...".to_string()),
        CheckKind::UndefinedName("...".to_string()),
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -19,10 +19,12 @@ classifiers = [
 ]
 author = "Charlie Marsh"
 author_email = "charlie.r.marsh@gmail.com"
-url = "https://github.com/charliermarsh/ruff"
 description = "An extremely fast Python linter, written in Rust."
 requires-python = ">=3.7"

+[project.urls]
+repository = "https://github.com/charliermarsh/ruff"
+
 [build-system]
 requires = ["maturin>=0.13,<0.14"]
 build-backend = "maturin"
--- a/resources/test/fixtures/E711.py
+++ b/resources/test/fixtures/E711.py
@@ -1,11 +1,50 @@
-if var == None:
+#: E711
+if res == None:
+    pass
+#: E711
+if res != None:
+    pass
+#: E711
+if None == res:
+    pass
+#: E711
+if None != res:
+    pass
+#: E711
+if res[1] == None:
+    pass
+#: E711
+if res[1] != None:
+    pass
+#: E711
+if None != res[1]:
+    pass
+#: E711
+if None == res[1]:
    pass

-if None != var:
+#: Okay
+if x not in y:
    pass

-if var is None:
+if not (X in Y or X is Z):
    pass

-if None is not var:
+if not (X in Y):
    pass
+
+if x is not y:
+    pass
+
+if X is not Y is not Z:
+    pass
+
+if TrueElement.get_element(True) == TrueElement.get_element(False):
+    pass
+
+if (True) == TrueElement or x == TrueElement:
+    pass
+
+assert (not foo) in bar
+assert {"x": not foo} in bar
+assert [42, not foo] in bar
--- a/resources/test/fixtures/E712.py
+++ b/resources/test/fixtures/E712.py
@@ -1,14 +1,46 @@
-if var == True:
+#: E712
+if res == True:
+    pass
+#: E712
+if res != False:
+    pass
+#: E712
+if True != res:
+    pass
+#: E712
+if False == res:
+    pass
+#: E712
+if res[1] == True:
+    pass
+#: E712
+if res[1] != False:
+    pass
+#: E712
+var = 1 if cond == True else -1 if cond == False else cond
+#: E712
+if (True) == TrueElement or x == TrueElement:
    pass

-if False != var:
+#: Okay
+if x not in y:
    pass

-if var != False != True:
+if not (X in Y or X is Z):
    pass

-if var is True:
+if not (X in Y):
    pass

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

-my_list = [1, 2, 3]
-if num not in my_list:
-    print(num)
+#: Okay
+if x not in y:
+    pass
+
+if not (X in Y or X is Z):
+    pass
+
+if x is not y:
+    pass
+
+if X is not Y is not Z:
+    pass
+
+if TrueElement.get_element(True) == TrueElement.get_element(False):
+    pass
+
+if (True) == TrueElement or x == TrueElement:
+    pass
+
+assert (not foo) in bar
+assert {"x": not foo} in bar
+assert [42, not foo] in bar
--- a/resources/test/fixtures/E714.py
+++ b/resources/test/fixtures/E714.py
@@ -1,5 +1,38 @@
-if not user is None:
-    print(user.name)
+#: E714
+if not X is Y:
+    pass
+#: E714
+if not X.B is Y:
+    pass
+#: E714
+if not X is Y is not Z:
+    pass

-if user is not None:
-    print(user.name)
+#: Okay
+if not X is not Y:
+    pass
+
+if x not in y:
+    pass
+
+if not (X in Y or X is Z):
+    pass
+
+if not (X in Y):
+    pass
+
+if x is not y:
+    pass
+
+if X is not Y is not Z:
+    pass
+
+if TrueElement.get_element(True) == TrueElement.get_element(False):
+    pass
+
+if (True) == TrueElement or x == TrueElement:
+    pass
+
+assert (not foo) in bar
+assert {"x": not foo} in bar
+assert [42, not foo] in bar
--- a/resources/test/fixtures/E721.py
+++ b/resources/test/fixtures/E721.py
@@ -0,0 +1,54 @@
+#: E721
+if type(res) == type(42):
+    pass
+#: E721
+if type(res) != type(""):
+    pass
+#: E721
+import types
+
+if res == types.IntType:
+    pass
+#: E721
+import types
+
+if type(res) is not types.ListType:
+    pass
+#: E721
+assert type(res) == type(False) or type(res) == type(None)
+#: E721
+assert type(res) == type([])
+#: E721
+assert type(res) == type(())
+#: E721
+assert type(res) == type((0,))
+#: E721
+assert type(res) == type((0))
+#: E721
+assert type(res) != type((1,))
+#: E721
+assert type(res) is type((1,))
+#: E721
+assert type(res) is not type((1,))
+#: E211 E721
+assert type(res) == type(
+    [
+        2,
+    ]
+)
+#: E201 E201 E202 E721
+assert type(res) == type(())
+#: E201 E202 E721
+assert type(res) == type((0,))
+
+#: Okay
+import types
+
+if isinstance(res, int):
+    pass
+if isinstance(res, str):
+    pass
+if isinstance(res, types.MethodType):
+    pass
+if type(a) != type(b) or type(a) == type(ccc):
+    pass
--- a/resources/test/fixtures/E722.py
+++ b/resources/test/fixtures/E722.py
@@ -0,0 +1,33 @@
+#: E722
+try:
+    pass
+except:
+    pass
+#: E722
+try:
+    pass
+except Exception:
+    pass
+except:
+    pass
+#: E722
+try:
+    pass
+except:
+    pass
+#: Okay
+fake_code = """"
+try:
+    do_something()
+except:
+    pass
+"""
+try:
+    pass
+except Exception:
+    pass
+#: Okay
+from . import compute_type
+
+if compute_type(foo) == 5:
+    pass
--- a/resources/test/fixtures/E731.py
+++ b/resources/test/fixtures/E731.py
@@ -1,6 +1,21 @@
-from typing import Callable, Iterable
+#: E731
+f = lambda x: 2 * x
+#: E731
+f = lambda x: 2 * x
+#: E731
+while False:
+    this = lambda y, z: 2 * x

-a = lambda x: x**2
-b = map(lambda x: 2 * x, range(3))
-c: Callable = lambda x: x**2
-d: Iterable = map(lambda x: 2 * x, range(3))
+
+f = object()
+#: E731
+f.method = lambda: "Method"
+
+f = {}
+#: E731
+f["a"] = lambda x: x ** 2
+
+f = []
+f.append(lambda x: x ** 2)
+
+lambda: "no-op"
--- a/resources/test/fixtures/E741.py
+++ b/resources/test/fixtures/E741.py
@@ -0,0 +1,75 @@
+from contextlib import contextmanager
+
+l = 0
+I = 0
+O = 0
+l: int = 0
+
+a, l = 0, 1
+[a, l] = 0, 1
+a, *l = 0, 1, 2
+a = l = 0
+
+o = 0
+i = 0
+
+for l in range(3):
+    pass
+
+
+for a, l in zip(range(3), range(3)):
+    pass
+
+
+def f1():
+    global l
+    l = 0
+
+
+def f2():
+    l = 0
+
+    def f3():
+        nonlocal l
+        l = 1
+
+    f3()
+    return l
+
+
+def f4(l, /, I):
+    return l, I, O
+
+
+def f5(l=0, *, I=1):
+    return l, I
+
+
+def f6(*l, **I):
+    return l, I
+
+
+@contextmanager
+def ctx1():
+    yield 0
+
+
+with ctx1() as l:
+    pass
+
+
+@contextmanager
+def ctx2():
+    yield 0, 1
+
+
+with ctx2() as (a, l):
+    pass
+
+try:
+    pass
+except ValueError as l:
+    pass
+
+if (l := 5) > 0:
+    pass
--- a/resources/test/fixtures/E742.py
+++ b/resources/test/fixtures/E742.py
@@ -0,0 +1,14 @@
+class l:
+    pass
+
+
+class I:
+    pass
+
+
+class O:
+    pass
+
+
+class X:
+    pass
--- a/resources/test/fixtures/E743.py
+++ b/resources/test/fixtures/E743.py
@@ -0,0 +1,15 @@
+def l():
+    pass
+
+
+def I():
+    pass
+
+
+class X:
+    def O(self):
+        pass
+
+
+def x():
+    pass
--- a/resources/test/fixtures/E999.py
+++ b/resources/test/fixtures/E999.py
@@ -0,0 +1,2 @@
+def x():
+
--- a/resources/test/fixtures/F401.py
+++ b/resources/test/fixtures/F401.py
@@ -1,6 +1,7 @@
 from __future__ import all_feature_names
 import os
 import functools
+from datetime import datetime
 from collections import (
    Counter,
    OrderedDict,
@@ -10,11 +11,18 @@ 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()
@@ -23,3 +31,11 @@ class X:

 __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)
--- a/resources/test/fixtures/F404.py
+++ b/resources/test/fixtures/F404.py
@@ -0,0 +1,7 @@
+from __future__ import print_function
+"""Docstring"""
+from __future__ import absolute_import
+
+from collections import namedtuple
+
+from __future__ import print_function
--- a/resources/test/fixtures/F406.py
+++ b/resources/test/fixtures/F406.py
@@ -0,0 +1,9 @@
+from F634 import *
+
+
+def f():
+    from F634 import *
+
+
+class F:
+    from F634 import *
--- a/resources/test/fixtures/F407.py
+++ b/resources/test/fixtures/F407.py
@@ -0,0 +1,2 @@
+from __future__ import print_function
+from __future__ import non_existent_feature
--- a/resources/test/fixtures/F601.py
+++ b/resources/test/fixtures/F601.py
@@ -0,0 +1,12 @@
+x = {
+    "a": 1,
+    "a": 2,
+    "b": 3,
+    ("a", "b"): 3,
+    ("a", "b"): 4,
+    1.0: 2,
+    1: 0,
+    1: 3,
+    b"123": 1,
+    b"123": 4,
+}
--- a/resources/test/fixtures/F602.py
+++ b/resources/test/fixtures/F602.py
@@ -0,0 +1,7 @@
+a = 1
+b = 2
+x = {
+    a: 1,
+    a: 2,
+    b: 3,
+}
--- a/resources/test/fixtures/F622.py
+++ b/resources/test/fixtures/F622.py
@@ -0,0 +1,3 @@
+*a, *b, c = (1, 2, 3)
+*a, b, c = (1, 2, 3)
+a, b, *c = (1, 2, 3)
--- a/resources/test/fixtures/F632.py
+++ b/resources/test/fixtures/F632.py
@@ -0,0 +1,5 @@
+if x is "abc":
+    pass
+
+if 123 is not y:
+    pass
--- a/resources/test/fixtures/F633.py
+++ b/resources/test/fixtures/F633.py
@@ -0,0 +1,4 @@
+from __future__ import print_function
+import sys
+
+print >> sys.stderr, "Hello"
--- a/resources/test/fixtures/F701.py
+++ b/resources/test/fixtures/F701.py
@@ -0,0 +1,23 @@
+for i in range(10):
+    break
+else:
+    break
+
+i = 0
+while i < 10:
+    i += 1
+    break
+
+
+def f():
+    for i in range(10):
+        break
+
+    break
+
+
+class Foo:
+    break
+
+
+break
--- a/resources/test/fixtures/F702.py
+++ b/resources/test/fixtures/F702.py
@@ -0,0 +1,23 @@
+for i in range(10):
+    continue
+else:
+    continue
+
+i = 0
+while i < 10:
+    i += 1
+    continue
+
+
+def f():
+    for i in range(10):
+        continue
+
+    continue
+
+
+class Foo:
+    continue
+
+
+continue
--- a/resources/test/fixtures/F722.py
+++ b/resources/test/fixtures/F722.py
@@ -0,0 +1,10 @@
+class A:
+    pass
+
+
+def f() -> "A":
+    pass
+
+
+def g() -> "///":
+    pass
--- a/resources/test/fixtures/F821.py
+++ b/resources/test/fixtures/F821.py
@@ -36,10 +36,15 @@ class Foo:
    ANNOTATED_CLASS_VAR: int = 2


+from typing import Literal
+
+
 class Class:
+    copy_on_model_validation: Literal["none", "deep", "shallow"]
+    post_init_call: Literal["before_validation", "after_validation"]
+
    def __init__(self):
-        # TODO(charlie): This should be recognized as a defined variable.
-        Class  # noqa: F821
+        Class


 try:
@@ -49,3 +54,31 @@ except Exception as e:


 y: int = 1
+
+x: "Bar" = 1
+
+[first] = ["yup"]
+
+
+from typing import List, TypedDict
+
+
+class Item(TypedDict):
+    nodes: List[TypedDict("Node", {"name": str})]
+
+
+from enum import Enum
+
+
+class Ticket:
+    class Status(Enum):
+        OPEN = "OPEN"
+        CLOSED = "CLOSED"
+
+    def set_status(self, status: Status):
+        self.status = status
+
+
+def update_tomato():
+    print(TOMATO)
+    TOMATO = "cherry tomato"
--- a/resources/test/fixtures/F841.py
+++ b/resources/test/fixtures/F841.py
@@ -14,3 +14,11 @@ def f():
    x = 1
    y = 2
    z = x + y
+
+
+def g():
+    foo = (1, 2)
+    (a, b) = (1, 2)
+
+    bar = (1, 2)
+    (c, d) = bar
--- a/resources/test/fixtures/init.py
+++ b/resources/test/fixtures/init.py
@@ -0,0 +1,3 @@
+print(__path__)
+
+__all__ = ["a", "b", "c"]
--- a/resources/test/fixtures/directory/also_excluded.py
+++ b/resources/test/fixtures/directory/also_excluded.py
@@ -0,0 +1,9 @@
+a = "abc"
+b = f"ghi{'jkl'}"
+
+c = f"def"
+d = f"def" + "ghi"
+e = (
+    f"def" +
+    "ghi"
+)
--- a/resources/test/fixtures/future_annotations.py
+++ b/resources/test/fixtures/future_annotations.py
@@ -0,0 +1,27 @@
+from __future__ import annotations
+
+from dataclasses import dataclass
+
+from models import Fruit, Nut
+
+
+@dataclass
+class Foo:
+    x: int
+    y: int
+
+    @classmethod
+    def a(cls) -> Foo:
+        return cls(x=0, y=0)
+
+    @classmethod
+    def b(cls) -> "Foo":
+        return cls(x=0, y=0)
+
+    @classmethod
+    def c(cls) -> Bar:
+        return cls(x=0, y=0)
+
+    @classmethod
+    def d(cls) -> Fruit:
+        return cls(x=0, y=0)
--- a/resources/test/fixtures/pyproject.toml
+++ b/resources/test/fixtures/pyproject.toml
@@ -1,6 +1,10 @@
 [tool.ruff]
 line-length = 88
-exclude = ["excluded.py", "**/migrations"]
+extend-exclude = [
+    "excluded.py",
+    "migrations",
+    "./resources/test/fixtures/directory/also_excluded.py",
+]
 select = [
    "E402",
    "E501",
@@ -8,16 +12,34 @@ select = [
    "E712",
    "E713",
    "E714",
+    "E721",
+    "E722",
    "E731",
+    "E741",
+    "E742",
+    "E743",
    "E902",
+    "E999",
    "F401",
    "F403",
+    "F404",
+    "F406",
+    "F407",
    "F541",
+    "F601",
+    "F602",
+    "F621",
+    "F622",
    "F631",
+    "F632",
+    "F633",
    "F634",
+    "F701",
+    "F702",
    "F704",
    "F706",
    "F707",
+    "F722",
    "F821",
    "F822",
    "F823",
--- a/src/ast.rs
+++ b/src/ast.rs
@@ -0,0 +1,5 @@
+pub mod checks;
+pub mod operations;
+pub mod relocate;
+pub mod types;
+pub mod visitor;
--- a/src/ast/checks.rs
+++ b/src/ast/checks.rs
@@ -0,0 +1,626 @@
+use std::collections::BTreeSet;
+
+use itertools::izip;
+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, Scope};
+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,
+) -> 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, operand.location));
+                        }
+                    }
+                    Cmpop::Is => {
+                        if check_not_is {
+                            checks.push(Check::new(CheckKind::NotIsTest, operand.location));
+                        }
+                    }
+                    _ => {}
+                }
+            }
+        }
+    }
+
+    checks
+}
+
+/// Check UnusedVariable compliance.
+pub fn check_unused_variables(scope: &Scope) -> Vec<Check> {
+    let mut checks: Vec<Check> = vec![];
+
+    for (name, binding) in scope.values.iter() {
+        // TODO(charlie): Ignore if using `locals`.
+        if binding.used.is_none()
+            && name != "_"
+            && name != "__tracebackhide__"
+            && name != "__traceback_info__"
+            && name != "__traceback_supplement__"
+            && matches!(binding.kind, BindingKind::Assignment)
+        {
+            checks.push(Check::new(
+                CheckKind::UnusedVariable(name.to_string()),
+                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,
+) -> 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,
+                            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()),
+                            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,
+) -> 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),
+                comparator.location,
+            ));
+        }
+        if matches!(op, Cmpop::NotEq) {
+            checks.push(Check::new(
+                CheckKind::NoneComparison(RejectedCmpop::NotEq),
+                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),
+                    comparator.location,
+                ));
+            }
+            if matches!(op, Cmpop::NotEq) {
+                checks.push(Check::new(
+                    CheckKind::TrueFalseComparison(value, RejectedCmpop::NotEq),
+                    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),
+                    comparator.location,
+                ));
+            }
+            if matches!(op, Cmpop::NotEq) {
+                checks.push(Check::new(
+                    CheckKind::NoneComparison(RejectedCmpop::NotEq),
+                    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),
+                        comparator.location,
+                    ));
+                }
+                if matches!(op, Cmpop::NotEq) {
+                    checks.push(Check::new(
+                        CheckKind::TrueFalseComparison(value, RejectedCmpop::NotEq),
+                        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],
+    location: Location,
+    check_too_many_expressions: bool,
+    check_two_starred_expressions: bool,
+) -> 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],
+) -> 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, stmt.location))
+    } else {
+        None
+    }
+}
+
+/// Check ContinueOutsideLoop compliance.
+pub fn check_continue_outside_loop(
+    stmt: &Stmt,
+    parents: &[&Stmt],
+    parent_stack: &[usize],
+) -> 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, stmt.location))
+    } else {
+        None
+    }
+}
--- a/src/ast/operations.rs
+++ b/src/ast/operations.rs
@@ -1,56 +1,6 @@
-use std::collections::BTreeMap;
-use std::sync::atomic::{AtomicUsize, Ordering};
-
 use rustpython_parser::ast::{Constant, Expr, ExprKind, Location, Stmt, StmtKind};

-fn id() -> usize {
-    static COUNTER: AtomicUsize = AtomicUsize::new(1);
-    COUNTER.fetch_add(1, Ordering::Relaxed)
-}
-
-pub enum ScopeKind {
-    Class,
-    Function,
-    Generator,
-    Module,
-}
-
-pub struct Scope {
-    pub id: usize,
-    pub kind: ScopeKind,
-    pub values: BTreeMap<String, Binding>,
-}
-
-impl Scope {
-    pub fn new(kind: ScopeKind) -> Self {
-        Scope {
-            id: id(),
-            kind,
-            values: BTreeMap::new(),
-        }
-    }
-}
-
-#[derive(Clone, Debug)]
-pub enum BindingKind {
-    Argument,
-    Assignment,
-    Builtin,
-    ClassDefinition,
-    Definition,
-    Export(Vec<String>),
-    FutureImportation,
-    Importation(String),
-    StarImportation,
-    SubmoduleImportation(String),
-}
-
-#[derive(Clone, Debug)]
-pub struct Binding {
-    pub kind: BindingKind,
-    pub location: Location,
-    pub used: Option<usize>,
-}
+use crate::ast::types::{BindingKind, Scope};

 /// Extract the names bound to a given __all__ assignment.
 pub fn extract_all_names(stmt: &Stmt, scope: &Scope) -> Vec<String> {
@@ -72,7 +22,7 @@ pub fn extract_all_names(stmt: &Stmt, scope: &Scope) -> Vec<String> {
    if let StmtKind::AugAssign { .. } = &stmt.node {
        if let Some(binding) = scope.values.get("__all__") {
            if let BindingKind::Export(existing) = &binding.kind {
-                names.extend(existing.clone());
+                names.extend_from_slice(existing);
            }
        }
    }
@@ -116,6 +66,56 @@ pub fn extract_all_names(stmt: &Stmt, scope: &Scope) -> Vec<String> {
    names
 }

+/// Check if a node is parent of a conditional branch.
+pub fn on_conditional_branch(parent_stack: &[usize], parents: &[&Stmt]) -> bool {
+    for index in parent_stack.iter().rev() {
+        let parent = parents[*index];
+        if matches!(parent.node, StmtKind::If { .. } | StmtKind::While { .. }) {
+            return true;
+        }
+        if let StmtKind::Expr { value } = &parent.node {
+            if matches!(value.node, ExprKind::IfExp { .. }) {
+                return true;
+            }
+        }
+    }
+
+    false
+}
+
+/// Check if a node is in a nested block.
+pub fn in_nested_block(parent_stack: &[usize], parents: &[&Stmt]) -> bool {
+    for index in parent_stack.iter().rev() {
+        let parent = parents[*index];
+        if matches!(
+            parent.node,
+            StmtKind::Try { .. } | StmtKind::If { .. } | StmtKind::With { .. }
+        ) {
+            return true;
+        }
+    }
+
+    false
+}
+
+/// Check if a node represents an unpacking assignment.
+pub fn is_unpacking_assignment(stmt: &Stmt) -> bool {
+    if let StmtKind::Assign { targets, value, .. } = &stmt.node {
+        for child in targets {
+            match &child.node {
+                ExprKind::Set { .. } | ExprKind::List { .. } | ExprKind::Tuple { .. } => {}
+                _ => return false,
+            }
+        }
+        match &value.node {
+            ExprKind::Set { .. } | ExprKind::List { .. } | ExprKind::Tuple { .. } => return false,
+            _ => {}
+        }
+        return true;
+    }
+    false
+}
+
 /// Struct used to efficiently slice source code at (row, column) Locations.
 pub struct SourceCodeLocator<'a> {
    content: &'a str,
--- a/src/ast/relocate.rs
+++ b/src/ast/relocate.rs
@@ -0,0 +1,137 @@
+use rustpython_parser::ast::{Expr, ExprKind, Keyword, Location};
+
+fn relocate_keyword(keyword: &mut Keyword, location: Location) {
+    keyword.location = 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;
+    match &mut expr.node {
+        ExprKind::BoolOp { values, .. } => {
+            for expr in values {
+                relocate_expr(expr, location);
+            }
+        }
+        ExprKind::NamedExpr { target, value } => {
+            relocate_expr(target, location);
+            relocate_expr(value, location);
+        }
+        ExprKind::BinOp { left, right, .. } => {
+            relocate_expr(left, location);
+            relocate_expr(right, location);
+        }
+        ExprKind::UnaryOp { operand, .. } => {
+            relocate_expr(operand, location);
+        }
+        ExprKind::Lambda { body, .. } => {
+            relocate_expr(body, location);
+        }
+        ExprKind::IfExp { test, body, orelse } => {
+            relocate_expr(test, location);
+            relocate_expr(body, location);
+            relocate_expr(orelse, location);
+        }
+        ExprKind::Dict { keys, values } => {
+            for expr in keys {
+                relocate_expr(expr, location);
+            }
+            for expr in values {
+                relocate_expr(expr, location);
+            }
+        }
+        ExprKind::Set { elts } => {
+            for expr in elts {
+                relocate_expr(expr, location);
+            }
+        }
+        ExprKind::ListComp { elt, .. } => {
+            relocate_expr(elt, location);
+        }
+        ExprKind::SetComp { elt, .. } => {
+            relocate_expr(elt, location);
+        }
+        ExprKind::DictComp { key, value, .. } => {
+            relocate_expr(key, location);
+            relocate_expr(value, location);
+        }
+        ExprKind::GeneratorExp { elt, .. } => {
+            relocate_expr(elt, location);
+        }
+        ExprKind::Await { value } => relocate_expr(value, location),
+        ExprKind::Yield { value } => {
+            if let Some(expr) = value {
+                relocate_expr(expr, location);
+            }
+        }
+        ExprKind::YieldFrom { value } => relocate_expr(value, location),
+        ExprKind::Compare {
+            left, comparators, ..
+        } => {
+            relocate_expr(left, location);
+            for expr in comparators {
+                relocate_expr(expr, location);
+            }
+        }
+        ExprKind::Call {
+            func,
+            args,
+            keywords,
+        } => {
+            relocate_expr(func, location);
+            for expr in args {
+                relocate_expr(expr, location);
+            }
+            for keyword in keywords {
+                relocate_keyword(keyword, location);
+            }
+        }
+        ExprKind::FormattedValue {
+            value, format_spec, ..
+        } => {
+            relocate_expr(value, location);
+            if let Some(expr) = format_spec {
+                relocate_expr(expr, location);
+            }
+        }
+        ExprKind::JoinedStr { values } => {
+            for expr in values {
+                relocate_expr(expr, location);
+            }
+        }
+        ExprKind::Constant { .. } => {}
+        ExprKind::Attribute { value, .. } => {
+            relocate_expr(value, location);
+        }
+        ExprKind::Subscript { value, slice, .. } => {
+            relocate_expr(value, location);
+            relocate_expr(slice, location);
+        }
+        ExprKind::Starred { value, .. } => {
+            relocate_expr(value, location);
+        }
+        ExprKind::Name { .. } => {}
+        ExprKind::List { elts, .. } => {
+            for expr in elts {
+                relocate_expr(expr, location);
+            }
+        }
+        ExprKind::Tuple { elts, .. } => {
+            for expr in elts {
+                relocate_expr(expr, location);
+            }
+        }
+        ExprKind::Slice { lower, upper, step } => {
+            if let Some(expr) = lower {
+                relocate_expr(expr, location);
+            }
+            if let Some(expr) = upper {
+                relocate_expr(expr, location);
+            }
+            if let Some(expr) = step {
+                relocate_expr(expr, location);
+            }
+        }
+    }
+}
--- a/src/ast/types.rs
+++ b/src/ast/types.rs
@@ -0,0 +1,59 @@
+use std::collections::BTreeMap;
+use std::sync::atomic::{AtomicUsize, Ordering};
+
+use rustpython_parser::ast::Location;
+
+fn id() -> usize {
+    static COUNTER: AtomicUsize = AtomicUsize::new(1);
+    COUNTER.fetch_add(1, Ordering::Relaxed)
+}
+
+#[derive(Clone, Debug)]
+pub enum ScopeKind {
+    Class,
+    Function,
+    Generator,
+    Module,
+}
+
+#[derive(Clone, Debug)]
+pub struct Scope {
+    pub id: usize,
+    pub kind: ScopeKind,
+    pub values: BTreeMap<String, Binding>,
+}
+
+impl Scope {
+    pub fn new(kind: ScopeKind) -> Self {
+        Scope {
+            id: id(),
+            kind,
+            values: BTreeMap::new(),
+        }
+    }
+}
+
+#[derive(Clone, Debug)]
+pub enum BindingKind {
+    Annotation,
+    Argument,
+    Assignment,
+    Binding,
+    Builtin,
+    ClassDefinition,
+    Definition,
+    Export(Vec<String>),
+    FutureImportation,
+    Importation(String),
+    StarImportation,
+    SubmoduleImportation(String),
+}
+
+#[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
+    /// last used.
+    pub used: Option<(usize, Location)>,
+}
--- a/src/ast/visitor.rs
+++ b/src/ast/visitor.rs
@@ -4,102 +4,141 @@ use rustpython_parser::ast::{
    PatternKind, Stmt, StmtKind, Unaryop, Withitem,
 };

-pub trait Visitor {
-    fn visit_stmt(&mut self, stmt: &Stmt) {
+pub trait Visitor<'a> {
+    fn visit_stmt(&mut self, stmt: &'a Stmt) {
        walk_stmt(self, stmt);
    }
-    fn visit_annotation(&mut self, expr: &Expr) {
+    fn visit_annotation(&mut self, expr: &'a Expr) {
        walk_expr(self, expr);
    }
-    fn visit_expr(&mut self, expr: &Expr, _parent: Option<&Stmt>) {
+    fn visit_expr(&mut self, expr: &'a Expr) {
        walk_expr(self, expr);
    }
-    fn visit_constant(&mut self, constant: &Constant) {
+    fn visit_constant(&mut self, constant: &'a Constant) {
        walk_constant(self, constant);
    }
-    fn visit_expr_context(&mut self, expr_content: &ExprContext) {
+    fn visit_expr_context(&mut self, expr_content: &'a ExprContext) {
        walk_expr_context(self, expr_content);
    }
-    fn visit_boolop(&mut self, boolop: &Boolop) {
+    fn visit_boolop(&mut self, boolop: &'a Boolop) {
        walk_boolop(self, boolop);
    }
-    fn visit_operator(&mut self, operator: &Operator) {
+    fn visit_operator(&mut self, operator: &'a Operator) {
        walk_operator(self, operator);
    }
-    fn visit_unaryop(&mut self, unaryop: &Unaryop) {
+    fn visit_unaryop(&mut self, unaryop: &'a Unaryop) {
        walk_unaryop(self, unaryop);
    }
-    fn visit_cmpop(&mut self, cmpop: &Cmpop) {
+    fn visit_cmpop(&mut self, cmpop: &'a Cmpop) {
        walk_cmpop(self, cmpop);
    }
-    fn visit_comprehension(&mut self, comprehension: &Comprehension) {
+    fn visit_comprehension(&mut self, comprehension: &'a Comprehension) {
        walk_comprehension(self, comprehension);
    }
-    fn visit_excepthandler(&mut self, excepthandler: &Excepthandler) {
+    fn visit_excepthandler(&mut self, excepthandler: &'a Excepthandler) {
        walk_excepthandler(self, excepthandler);
    }
-    fn visit_arguments(&mut self, arguments: &Arguments) {
+    fn visit_arguments(&mut self, arguments: &'a Arguments) {
        walk_arguments(self, arguments);
    }
-    fn visit_arg(&mut self, arg: &Arg) {
+    fn visit_arg(&mut self, arg: &'a Arg) {
        walk_arg(self, arg);
    }
-    fn visit_keyword(&mut self, keyword: &Keyword) {
+    fn visit_keyword(&mut self, keyword: &'a Keyword) {
        walk_keyword(self, keyword);
    }
-    fn visit_alias(&mut self, alias: &Alias) {
+    fn visit_alias(&mut self, alias: &'a Alias) {
        walk_alias(self, alias);
    }
-    fn visit_withitem(&mut self, withitem: &Withitem) {
+    fn visit_withitem(&mut self, withitem: &'a Withitem) {
        walk_withitem(self, withitem);
    }
-    fn visit_match_case(&mut self, match_case: &MatchCase) {
+    fn visit_match_case(&mut self, match_case: &'a MatchCase) {
        walk_match_case(self, match_case);
    }
-    fn visit_pattern(&mut self, pattern: &Pattern) {
+    fn visit_pattern(&mut self, pattern: &'a Pattern) {
        walk_pattern(self, pattern);
    }
 }

-pub fn walk_stmt<V: Visitor + ?Sized>(visitor: &mut V, stmt: &Stmt) {
+pub fn walk_stmt<'a, V: Visitor<'a> + ?Sized>(visitor: &mut V, stmt: &'a Stmt) {
    match &stmt.node {
-        StmtKind::FunctionDef { args, body, .. } => {
+        StmtKind::FunctionDef {
+            args,
+            body,
+            decorator_list,
+            returns,
+            ..
+        } => {
            visitor.visit_arguments(args);
+            for expr in decorator_list {
+                visitor.visit_expr(expr);
+            }
+            for expr in returns {
+                visitor.visit_annotation(expr);
+            }
            for stmt in body {
-                visitor.visit_stmt(stmt)
+                visitor.visit_stmt(stmt);
            }
        }
-        StmtKind::AsyncFunctionDef { args, body, .. } => {
+        StmtKind::AsyncFunctionDef {
+            args,
+            body,
+            decorator_list,
+            returns,
+            ..
+        } => {
            visitor.visit_arguments(args);
+            for expr in decorator_list {
+                visitor.visit_expr(expr);
+            }
+            for expr in returns {
+                visitor.visit_annotation(expr);
+            }
            for stmt in body {
-                visitor.visit_stmt(stmt)
+                visitor.visit_stmt(stmt);
            }
        }
-        StmtKind::ClassDef { body, .. } => {
+        StmtKind::ClassDef {
+            bases,
+            keywords,
+            body,
+            decorator_list,
+            ..
+        } => {
+            for expr in bases {
+                visitor.visit_expr(expr);
+            }
+            for keyword in keywords {
+                visitor.visit_keyword(keyword);
+            }
+            for expr in decorator_list {
+                visitor.visit_expr(expr);
+            }
            for stmt in body {
-                visitor.visit_stmt(stmt)
+                visitor.visit_stmt(stmt);
            }
        }
        StmtKind::Return { value } => {
            if let Some(expr) = value {
-                visitor.visit_expr(expr, Some(stmt))
+                visitor.visit_expr(expr);
            }
        }
        StmtKind::Delete { targets } => {
            for expr in targets {
-                visitor.visit_expr(expr, Some(stmt))
+                visitor.visit_expr(expr);
            }
        }
        StmtKind::Assign { targets, value, .. } => {
+            visitor.visit_expr(value);
            for expr in targets {
-                visitor.visit_expr(expr, Some(stmt))
+                visitor.visit_expr(expr);
            }
-            visitor.visit_expr(value, Some(stmt))
        }
        StmtKind::AugAssign { target, op, value } => {
-            visitor.visit_expr(target, Some(stmt));
+            visitor.visit_expr(target);
            visitor.visit_operator(op);
-            visitor.visit_expr(value, Some(stmt));
+            visitor.visit_expr(value);
        }
        StmtKind::AnnAssign {
            target,
@@ -107,11 +146,11 @@ pub fn walk_stmt<V: Visitor + ?Sized>(visitor: &mut V, stmt: &Stmt) {
            value,
            ..
        } => {
-            visitor.visit_expr(target, Some(stmt));
            visitor.visit_annotation(annotation);
            if let Some(expr) = value {
-                visitor.visit_expr(expr, Some(stmt))
+                visitor.visit_expr(expr);
            }
+            visitor.visit_expr(target);
        }
        StmtKind::For {
            target,
@@ -120,13 +159,13 @@ pub fn walk_stmt<V: Visitor + ?Sized>(visitor: &mut V, stmt: &Stmt) {
            orelse,
            ..
        } => {
-            visitor.visit_expr(target, Some(stmt));
-            visitor.visit_expr(iter, Some(stmt));
+            visitor.visit_expr(target);
+            visitor.visit_expr(iter);
            for stmt in body {
-                visitor.visit_stmt(stmt)
+                visitor.visit_stmt(stmt);
            }
            for stmt in orelse {
-                visitor.visit_stmt(stmt)
+                visitor.visit_stmt(stmt);
            }
        }
        StmtKind::AsyncFor {
@@ -136,31 +175,31 @@ pub fn walk_stmt<V: Visitor + ?Sized>(visitor: &mut V, stmt: &Stmt) {
            orelse,
            ..
        } => {
-            visitor.visit_expr(target, Some(stmt));
-            visitor.visit_expr(iter, Some(stmt));
+            visitor.visit_expr(target);
+            visitor.visit_expr(iter);
            for stmt in body {
-                visitor.visit_stmt(stmt)
+                visitor.visit_stmt(stmt);
            }
            for stmt in orelse {
-                visitor.visit_stmt(stmt)
+                visitor.visit_stmt(stmt);
            }
        }
        StmtKind::While { test, body, orelse } => {
-            visitor.visit_expr(test, Some(stmt));
+            visitor.visit_expr(test);
            for stmt in body {
-                visitor.visit_stmt(stmt)
+                visitor.visit_stmt(stmt);
            }
            for stmt in orelse {
-                visitor.visit_stmt(stmt)
+                visitor.visit_stmt(stmt);
            }
        }
        StmtKind::If { test, body, orelse } => {
-            visitor.visit_expr(test, Some(stmt));
+            visitor.visit_expr(test);
            for stmt in body {
-                visitor.visit_stmt(stmt)
+                visitor.visit_stmt(stmt);
            }
            for stmt in orelse {
-                visitor.visit_stmt(stmt)
+                visitor.visit_stmt(stmt);
            }
        }
        StmtKind::With { items, body, .. } => {
@@ -168,7 +207,7 @@ pub fn walk_stmt<V: Visitor + ?Sized>(visitor: &mut V, stmt: &Stmt) {
                visitor.visit_withitem(withitem);
            }
            for stmt in body {
-                visitor.visit_stmt(stmt)
+                visitor.visit_stmt(stmt);
            }
        }
        StmtKind::AsyncWith { items, body, .. } => {
@@ -176,22 +215,22 @@ pub fn walk_stmt<V: Visitor + ?Sized>(visitor: &mut V, stmt: &Stmt) {
                visitor.visit_withitem(withitem);
            }
            for stmt in body {
-                visitor.visit_stmt(stmt)
+                visitor.visit_stmt(stmt);
            }
        }
        StmtKind::Match { subject, cases } => {
            // TODO(charlie): Handle `cases`.
-            visitor.visit_expr(subject, Some(stmt));
+            visitor.visit_expr(subject);
            for match_case in cases {
                visitor.visit_match_case(match_case);
            }
        }
        StmtKind::Raise { exc, cause } => {
            if let Some(expr) = exc {
-                visitor.visit_expr(expr, Some(stmt))
+                visitor.visit_expr(expr);
            };
            if let Some(expr) = cause {
-                visitor.visit_expr(expr, Some(stmt))
+                visitor.visit_expr(expr);
            };
        }
        StmtKind::Try {
@@ -201,22 +240,22 @@ pub fn walk_stmt<V: Visitor + ?Sized>(visitor: &mut V, stmt: &Stmt) {
            finalbody,
        } => {
            for stmt in body {
-                visitor.visit_stmt(stmt)
+                visitor.visit_stmt(stmt);
            }
            for excepthandler in handlers {
                visitor.visit_excepthandler(excepthandler)
            }
            for stmt in orelse {
-                visitor.visit_stmt(stmt)
+                visitor.visit_stmt(stmt);
            }
            for stmt in finalbody {
-                visitor.visit_stmt(stmt)
+                visitor.visit_stmt(stmt);
            }
        }
        StmtKind::Assert { test, msg } => {
-            visitor.visit_expr(test, None);
+            visitor.visit_expr(test);
            if let Some(expr) = msg {
-                visitor.visit_expr(expr, Some(stmt))
+                visitor.visit_expr(expr);
            }
        }
        StmtKind::Import { names } => {
@@ -231,67 +270,67 @@ pub fn walk_stmt<V: Visitor + ?Sized>(visitor: &mut V, stmt: &Stmt) {
        }
        StmtKind::Global { .. } => {}
        StmtKind::Nonlocal { .. } => {}
-        StmtKind::Expr { value } => visitor.visit_expr(value, Some(stmt)),
+        StmtKind::Expr { value } => visitor.visit_expr(value),
        StmtKind::Pass => {}
        StmtKind::Break => {}
        StmtKind::Continue => {}
    }
 }

-pub fn walk_expr<V: Visitor + ?Sized>(visitor: &mut V, expr: &Expr) {
+pub fn walk_expr<'a, V: Visitor<'a> + ?Sized>(visitor: &mut V, expr: &'a Expr) {
    match &expr.node {
        ExprKind::BoolOp { op, values } => {
            visitor.visit_boolop(op);
            for expr in values {
-                visitor.visit_expr(expr, None)
+                visitor.visit_expr(expr);
            }
        }
        ExprKind::NamedExpr { target, value } => {
-            visitor.visit_expr(target, None);
-            visitor.visit_expr(value, None);
+            visitor.visit_expr(target);
+            visitor.visit_expr(value);
        }
        ExprKind::BinOp { left, op, right } => {
-            visitor.visit_expr(left, None);
+            visitor.visit_expr(left);
            visitor.visit_operator(op);
-            visitor.visit_expr(right, None);
+            visitor.visit_expr(right);
        }
        ExprKind::UnaryOp { op, operand } => {
            visitor.visit_unaryop(op);
-            visitor.visit_expr(operand, None);
+            visitor.visit_expr(operand);
        }
        ExprKind::Lambda { args, body } => {
            visitor.visit_arguments(args);
-            visitor.visit_expr(body, None);
+            visitor.visit_expr(body);
        }
        ExprKind::IfExp { test, body, orelse } => {
-            visitor.visit_expr(test, None);
-            visitor.visit_expr(body, None);
-            visitor.visit_expr(orelse, None);
+            visitor.visit_expr(test);
+            visitor.visit_expr(body);
+            visitor.visit_expr(orelse);
        }
        ExprKind::Dict { keys, values } => {
            for expr in keys {
-                visitor.visit_expr(expr, None)
+                visitor.visit_expr(expr);
            }
            for expr in values {
-                visitor.visit_expr(expr, None)
+                visitor.visit_expr(expr);
            }
        }
        ExprKind::Set { elts } => {
            for expr in elts {
-                visitor.visit_expr(expr, None)
+                visitor.visit_expr(expr);
            }
        }
        ExprKind::ListComp { elt, generators } => {
            for comprehension in generators {
-                visitor.visit_comprehension(comprehension)
+                visitor.visit_comprehension(comprehension);
            }
-            visitor.visit_expr(elt, None);
+            visitor.visit_expr(elt);
        }
        ExprKind::SetComp { elt, generators } => {
            for comprehension in generators {
-                visitor.visit_comprehension(comprehension)
+                visitor.visit_comprehension(comprehension);
            }
-            visitor.visit_expr(elt, None);
+            visitor.visit_expr(elt);
        }
        ExprKind::DictComp {
            key,
@@ -299,35 +338,35 @@ pub fn walk_expr<V: Visitor + ?Sized>(visitor: &mut V, expr: &Expr) {
            generators,
        } => {
            for comprehension in generators {
-                visitor.visit_comprehension(comprehension)
+                visitor.visit_comprehension(comprehension);
            }
-            visitor.visit_expr(key, None);
-            visitor.visit_expr(value, None);
+            visitor.visit_expr(key);
+            visitor.visit_expr(value);
        }
        ExprKind::GeneratorExp { elt, generators } => {
            for comprehension in generators {
-                visitor.visit_comprehension(comprehension)
+                visitor.visit_comprehension(comprehension);
            }
-            visitor.visit_expr(elt, None);
+            visitor.visit_expr(elt);
        }
-        ExprKind::Await { value } => visitor.visit_expr(value, None),
+        ExprKind::Await { value } => visitor.visit_expr(value),
        ExprKind::Yield { value } => {
            if let Some(expr) = value {
-                visitor.visit_expr(expr, None)
+                visitor.visit_expr(expr);
            }
        }
-        ExprKind::YieldFrom { value } => visitor.visit_expr(value, None),
+        ExprKind::YieldFrom { value } => visitor.visit_expr(value),
        ExprKind::Compare {
            left,
            ops,
            comparators,
        } => {
-            visitor.visit_expr(left, None);
+            visitor.visit_expr(left);
            for cmpop in ops {
                visitor.visit_cmpop(cmpop);
            }
            for expr in comparators {
-                visitor.visit_expr(expr, None)
+                visitor.visit_expr(expr);
            }
        }
        ExprKind::Call {
@@ -335,9 +374,9 @@ pub fn walk_expr<V: Visitor + ?Sized>(visitor: &mut V, expr: &Expr) {
            args,
            keywords,
        } => {
-            visitor.visit_expr(func, None);
+            visitor.visit_expr(func);
            for expr in args {
-                visitor.visit_expr(expr, None);
+                visitor.visit_expr(expr);
            }
            for keyword in keywords {
                visitor.visit_keyword(keyword);
@@ -346,28 +385,28 @@ pub fn walk_expr<V: Visitor + ?Sized>(visitor: &mut V, expr: &Expr) {
        ExprKind::FormattedValue {
            value, format_spec, ..
        } => {
-            visitor.visit_expr(value, None);
+            visitor.visit_expr(value);
            if let Some(expr) = format_spec {
-                visitor.visit_expr(expr, None)
+                visitor.visit_expr(expr);
            }
        }
        ExprKind::JoinedStr { values } => {
            for expr in values {
-                visitor.visit_expr(expr, None)
+                visitor.visit_expr(expr);
            }
        }
        ExprKind::Constant { value, .. } => visitor.visit_constant(value),
        ExprKind::Attribute { value, ctx, .. } => {
-            visitor.visit_expr(value, None);
+            visitor.visit_expr(value);
            visitor.visit_expr_context(ctx);
        }
        ExprKind::Subscript { value, slice, ctx } => {
-            visitor.visit_expr(value, None);
-            visitor.visit_expr(slice, None);
+            visitor.visit_expr(value);
+            visitor.visit_expr(slice);
            visitor.visit_expr_context(ctx);
        }
        ExprKind::Starred { value, ctx } => {
-            visitor.visit_expr(value, None);
+            visitor.visit_expr(value);
            visitor.visit_expr_context(ctx);
        }
        ExprKind::Name { ctx, .. } => {
@@ -375,31 +414,31 @@ pub fn walk_expr<V: Visitor + ?Sized>(visitor: &mut V, expr: &Expr) {
        }
        ExprKind::List { elts, ctx } => {
            for expr in elts {
-                visitor.visit_expr(expr, None);
+                visitor.visit_expr(expr);
            }
            visitor.visit_expr_context(ctx);
        }
        ExprKind::Tuple { elts, ctx } => {
            for expr in elts {
-                visitor.visit_expr(expr, None);
+                visitor.visit_expr(expr);
            }
            visitor.visit_expr_context(ctx);
        }
        ExprKind::Slice { lower, upper, step } => {
            if let Some(expr) = lower {
-                visitor.visit_expr(expr, None);
+                visitor.visit_expr(expr);
            }
            if let Some(expr) = upper {
-                visitor.visit_expr(expr, None);
+                visitor.visit_expr(expr);
            }
            if let Some(expr) = step {
-                visitor.visit_expr(expr, None);
+                visitor.visit_expr(expr);
            }
        }
    }
 }

-pub fn walk_constant<V: Visitor + ?Sized>(visitor: &mut V, constant: &Constant) {
+pub fn walk_constant<'a, V: Visitor<'a> + ?Sized>(visitor: &mut V, constant: &'a Constant) {
    if let Constant::Tuple(constants) = constant {
        for constant in constants {
            visitor.visit_constant(constant)
@@ -407,19 +446,25 @@ pub fn walk_constant<V: Visitor + ?Sized>(visitor: &mut V, constant: &Constant)
    }
 }

-pub fn walk_comprehension<V: Visitor + ?Sized>(visitor: &mut V, comprehension: &Comprehension) {
-    visitor.visit_expr(&comprehension.target, None);
-    visitor.visit_expr(&comprehension.iter, None);
+pub fn walk_comprehension<'a, V: Visitor<'a> + ?Sized>(
+    visitor: &mut V,
+    comprehension: &'a Comprehension,
+) {
+    visitor.visit_expr(&comprehension.target);
+    visitor.visit_expr(&comprehension.iter);
    for expr in &comprehension.ifs {
-        visitor.visit_expr(expr, None);
+        visitor.visit_expr(expr);
    }
 }

-pub fn walk_excepthandler<V: Visitor + ?Sized>(visitor: &mut V, excepthandler: &Excepthandler) {
+pub fn walk_excepthandler<'a, V: Visitor<'a> + ?Sized>(
+    visitor: &mut V,
+    excepthandler: &'a Excepthandler,
+) {
    match &excepthandler.node {
        ExcepthandlerKind::ExceptHandler { type_, body, .. } => {
            if let Some(expr) = type_ {
-                visitor.visit_expr(expr, None);
+                visitor.visit_expr(expr);
            }
            for stmt in body {
                visitor.visit_stmt(stmt);
@@ -428,7 +473,7 @@ pub fn walk_excepthandler<V: Visitor + ?Sized>(visitor: &mut V, excepthandler: &
    }
 }

-pub fn walk_arguments<V: Visitor + ?Sized>(visitor: &mut V, arguments: &Arguments) {
+pub fn walk_arguments<'a, V: Visitor<'a> + ?Sized>(visitor: &mut V, arguments: &'a Arguments) {
    for arg in &arguments.posonlyargs {
        visitor.visit_arg(arg);
    }
@@ -436,61 +481,61 @@ pub fn walk_arguments<V: Visitor + ?Sized>(visitor: &mut V, arguments: &Argument
        visitor.visit_arg(arg);
    }
    if let Some(arg) = &arguments.vararg {
-        visitor.visit_arg(arg)
+        visitor.visit_arg(arg);
    }
    for arg in &arguments.kwonlyargs {
        visitor.visit_arg(arg);
    }
    for expr in &arguments.kw_defaults {
-        visitor.visit_expr(expr, None)
+        visitor.visit_expr(expr);
    }
    if let Some(arg) = &arguments.kwarg {
-        visitor.visit_arg(arg)
+        visitor.visit_arg(arg);
    }
    for expr in &arguments.defaults {
-        visitor.visit_expr(expr, None)
+        visitor.visit_expr(expr);
    }
 }

-pub fn walk_arg<V: Visitor + ?Sized>(visitor: &mut V, arg: &Arg) {
+pub fn walk_arg<'a, V: Visitor<'a> + ?Sized>(visitor: &mut V, arg: &'a Arg) {
    if let Some(expr) = &arg.node.annotation {
-        visitor.visit_annotation(expr)
+        visitor.visit_annotation(expr);
    }
 }

-pub fn walk_keyword<V: Visitor + ?Sized>(visitor: &mut V, keyword: &Keyword) {
-    visitor.visit_expr(&keyword.node.value, None);
+pub fn walk_keyword<'a, V: Visitor<'a> + ?Sized>(visitor: &mut V, keyword: &'a Keyword) {
+    visitor.visit_expr(&keyword.node.value);
 }

-pub fn walk_withitem<V: Visitor + ?Sized>(visitor: &mut V, withitem: &Withitem) {
-    visitor.visit_expr(&withitem.context_expr, None);
+pub fn walk_withitem<'a, V: Visitor<'a> + ?Sized>(visitor: &mut V, withitem: &'a Withitem) {
+    visitor.visit_expr(&withitem.context_expr);
    if let Some(expr) = &withitem.optional_vars {
-        visitor.visit_expr(expr, None);
+        visitor.visit_expr(expr);
    }
 }

-pub fn walk_match_case<V: Visitor + ?Sized>(visitor: &mut V, match_case: &MatchCase) {
+pub fn walk_match_case<'a, V: Visitor<'a> + ?Sized>(visitor: &mut V, match_case: &'a MatchCase) {
    visitor.visit_pattern(&match_case.pattern);
    if let Some(expr) = &match_case.guard {
-        visitor.visit_expr(expr, None);
+        visitor.visit_expr(expr);
    }
    for stmt in &match_case.body {
        visitor.visit_stmt(stmt);
    }
 }

-pub fn walk_pattern<V: Visitor + ?Sized>(visitor: &mut V, pattern: &Pattern) {
+pub fn walk_pattern<'a, V: Visitor<'a> + ?Sized>(visitor: &mut V, pattern: &'a Pattern) {
    match &pattern.node {
-        PatternKind::MatchValue { value } => visitor.visit_expr(value, None),
+        PatternKind::MatchValue { value } => visitor.visit_expr(value),
        PatternKind::MatchSingleton { value } => visitor.visit_constant(value),
        PatternKind::MatchSequence { patterns } => {
            for pattern in patterns {
-                visitor.visit_pattern(pattern)
+                visitor.visit_pattern(pattern);
            }
        }
        PatternKind::MatchMapping { keys, patterns, .. } => {
            for expr in keys {
-                visitor.visit_expr(expr, None);
+                visitor.visit_expr(expr);
            }
            for pattern in patterns {
                visitor.visit_pattern(pattern);
@@ -502,7 +547,7 @@ pub fn walk_pattern<V: Visitor + ?Sized>(visitor: &mut V, pattern: &Pattern) {
            kwd_patterns,
            ..
        } => {
-            visitor.visit_expr(cls, None);
+            visitor.visit_expr(cls);
            for pattern in patterns {
                visitor.visit_pattern(pattern);
            }
@@ -514,7 +559,7 @@ pub fn walk_pattern<V: Visitor + ?Sized>(visitor: &mut V, pattern: &Pattern) {
        PatternKind::MatchStar { .. } => {}
        PatternKind::MatchAs { pattern, .. } => {
            if let Some(pattern) = pattern {
-                visitor.visit_pattern(pattern)
+                visitor.visit_pattern(pattern);
            }
        }
        PatternKind::MatchOr { patterns } => {
@@ -527,24 +572,28 @@ pub fn walk_pattern<V: Visitor + ?Sized>(visitor: &mut V, pattern: &Pattern) {

 #[allow(unused_variables)]
 #[inline(always)]
-pub fn walk_expr_context<V: Visitor + ?Sized>(visitor: &mut V, expr_context: &ExprContext) {}
+pub fn walk_expr_context<'a, V: Visitor<'a> + ?Sized>(
+    visitor: &mut V,
+    expr_context: &'a ExprContext,
+) {
+}

 #[allow(unused_variables)]
 #[inline(always)]
-pub fn walk_boolop<V: Visitor + ?Sized>(visitor: &mut V, boolop: &Boolop) {}
+pub fn walk_boolop<'a, V: Visitor<'a> + ?Sized>(visitor: &mut V, boolop: &'a Boolop) {}

 #[allow(unused_variables)]
 #[inline(always)]
-pub fn walk_operator<V: Visitor + ?Sized>(visitor: &mut V, operator: &Operator) {}
+pub fn walk_operator<'a, V: Visitor<'a> + ?Sized>(visitor: &mut V, operator: &'a Operator) {}

 #[allow(unused_variables)]
 #[inline(always)]
-pub fn walk_unaryop<V: Visitor + ?Sized>(visitor: &mut V, unaryop: &Unaryop) {}
+pub fn walk_unaryop<'a, V: Visitor<'a> + ?Sized>(visitor: &mut V, unaryop: &'a Unaryop) {}

 #[allow(unused_variables)]
 #[inline(always)]
-pub fn walk_cmpop<V: Visitor + ?Sized>(visitor: &mut V, cmpop: &Cmpop) {}
+pub fn walk_cmpop<'a, V: Visitor<'a> + ?Sized>(visitor: &mut V, cmpop: &'a Cmpop) {}

 #[allow(unused_variables)]
 #[inline(always)]
-pub fn walk_alias<V: Visitor + ?Sized>(visitor: &mut V, alias: &Alias) {}
+pub fn walk_alias<'a, V: Visitor<'a> + ?Sized>(visitor: &mut V, alias: &'a Alias) {}
--- a/src/autofix.rs
+++ b/src/autofix.rs
@@ -1,216 +1,2 @@
-use std::fs;
-use std::path::Path;
-
-use anyhow::Result;
-use rustpython_parser::ast::Location;
-
-use crate::checks::{Check, Fix};
-
-#[derive(Hash)]
-pub enum Mode {
-    Generate,
-    Apply,
-    None,
-}
-
-impl From<bool> for Mode {
-    fn from(value: bool) -> Self {
-        match value {
-            true => Mode::Apply,
-            false => Mode::None,
-        }
-    }
-}
-
-/// Auto-fix errors in a file, and write the fixed source code to disk.
-pub fn fix_file(checks: &mut [Check], contents: &str, path: &Path) -> Result<()> {
-    if checks.iter().all(|check| check.fix.is_none()) {
-        return Ok(());
-    }
-
-    let output = apply_fixes(
-        checks.iter_mut().filter_map(|check| check.fix.as_mut()),
-        contents,
-    );
-
-    fs::write(path, output).map_err(|e| e.into())
-}
-
-/// Apply a series of fixes.
-fn apply_fixes<'a>(fixes: impl Iterator<Item = &'a mut Fix>, contents: &str) -> String {
-    let lines: Vec<&str> = contents.lines().collect();
-
-    let mut output = "".to_string();
-    let mut last_pos: Location = Location::new(0, 0);
-
-    for fix in fixes {
-        // Best-effort approach: if this fix overlaps with a fix we've already applied, skip it.
-        if last_pos > fix.start {
-            continue;
-        }
-
-        if fix.start.row() > last_pos.row() {
-            if last_pos.row() > 0 || last_pos.column() > 0 {
-                output.push_str(&lines[last_pos.row() - 1][last_pos.column() - 1..]);
-                output.push('\n');
-            }
-            for line in &lines[last_pos.row()..fix.start.row() - 1] {
-                output.push_str(line);
-                output.push('\n');
-            }
-            output.push_str(&lines[fix.start.row() - 1][..fix.start.column() - 1]);
-            output.push_str(&fix.content);
-        } else {
-            output.push_str(
-                &lines[last_pos.row() - 1][last_pos.column() - 1..fix.start.column() - 1],
-            );
-            output.push_str(&fix.content);
-        }
-
-        last_pos = fix.end;
-        fix.applied = true;
-    }
-
-    if last_pos.row() > 0 || last_pos.column() > 0 {
-        output.push_str(&lines[last_pos.row() - 1][last_pos.column() - 1..]);
-        output.push('\n');
-    }
-    for line in &lines[last_pos.row()..] {
-        output.push_str(line);
-        output.push('\n');
-    }
-
-    output
-}
-
-#[cfg(test)]
-mod tests {
-    use anyhow::Result;
-    use rustpython_parser::ast::Location;
-
-    use crate::autofix::apply_fixes;
-    use crate::checks::Fix;
-
-    #[test]
-    fn empty_file() -> Result<()> {
-        let mut fixes = vec![];
-        let actual = apply_fixes(fixes.iter_mut(), "");
-        let expected = "";
-
-        assert_eq!(actual, expected);
-
-        Ok(())
-    }
-
-    #[test]
-    fn apply_single_replacement() -> Result<()> {
-        let mut fixes = vec![Fix {
-            content: "Bar".to_string(),
-            start: Location::new(1, 9),
-            end: Location::new(1, 15),
-            applied: false,
-        }];
-        let actual = apply_fixes(
-            fixes.iter_mut(),
-            "class A(object):
-        ...
-",
-        );
-
-        let expected = "class A(Bar):
-        ...
-";
-
-        assert_eq!(actual, expected);
-
-        Ok(())
-    }
-
-    #[test]
-    fn apply_single_removal() -> Result<()> {
-        let mut fixes = vec![Fix {
-            content: "".to_string(),
-            start: Location::new(1, 8),
-            end: Location::new(1, 16),
-            applied: false,
-        }];
-        let actual = apply_fixes(
-            fixes.iter_mut(),
-            "class A(object):
-        ...
-",
-        );
-
-        let expected = "class A:
-        ...
-";
-
-        assert_eq!(actual, expected);
-
-        Ok(())
-    }
-
-    #[test]
-    fn apply_double_removal() -> Result<()> {
-        let mut fixes = vec![
-            Fix {
-                content: "".to_string(),
-                start: Location::new(1, 8),
-                end: Location::new(1, 17),
-                applied: false,
-            },
-            Fix {
-                content: "".to_string(),
-                start: Location::new(1, 17),
-                end: Location::new(1, 24),
-                applied: false,
-            },
-        ];
-        let actual = apply_fixes(
-            fixes.iter_mut(),
-            "class A(object, object):
-        ...
-",
-        );
-
-        let expected = "class A:
-        ...
-";
-
-        assert_eq!(actual, expected);
-
-        Ok(())
-    }
-
-    #[test]
-    fn ignore_overlapping_fixes() -> Result<()> {
-        let mut fixes = vec![
-            Fix {
-                content: "".to_string(),
-                start: Location::new(1, 8),
-                end: Location::new(1, 16),
-                applied: false,
-            },
-            Fix {
-                content: "ignored".to_string(),
-                start: Location::new(1, 10),
-                end: Location::new(1, 12),
-                applied: false,
-            },
-        ];
-        let actual = apply_fixes(
-            fixes.iter_mut(),
-            "class A(object):
-    ...
-",
-        );
-
-        let expected = "class A:
-    ...
-";
-
-        assert_eq!(actual, expected);
-
-        Ok(())
-    }
-}
+pub mod fixer;
+pub mod fixes;
--- a/src/autofix/fixer.rs
+++ b/src/autofix/fixer.rs
@@ -0,0 +1,216 @@
+use std::fs;
+use std::path::Path;
+
+use anyhow::Result;
+use rustpython_parser::ast::Location;
+
+use crate::checks::{Check, Fix};
+
+#[derive(Hash)]
+pub enum Mode {
+    Generate,
+    Apply,
+    None,
+}
+
+impl From<bool> for Mode {
+    fn from(value: bool) -> Self {
+        match value {
+            true => Mode::Apply,
+            false => Mode::None,
+        }
+    }
+}
+
+/// Auto-fix errors in a file, and write the fixed source code to disk.
+pub fn fix_file(checks: &mut [Check], contents: &str, path: &Path) -> Result<()> {
+    if checks.iter().all(|check| check.fix.is_none()) {
+        return Ok(());
+    }
+
+    let output = apply_fixes(
+        checks.iter_mut().filter_map(|check| check.fix.as_mut()),
+        contents,
+    );
+
+    fs::write(path, output).map_err(|e| e.into())
+}
+
+/// Apply a series of fixes.
+fn apply_fixes<'a>(fixes: impl Iterator<Item = &'a mut Fix>, contents: &str) -> String {
+    let lines: Vec<&str> = contents.lines().collect();
+
+    let mut output = "".to_string();
+    let mut last_pos: Location = Location::new(0, 0);
+
+    for fix in fixes {
+        // Best-effort approach: if this fix overlaps with a fix we've already applied, skip it.
+        if last_pos > fix.start {
+            continue;
+        }
+
+        if fix.start.row() > last_pos.row() {
+            if last_pos.row() > 0 || last_pos.column() > 0 {
+                output.push_str(&lines[last_pos.row() - 1][last_pos.column() - 1..]);
+                output.push('\n');
+            }
+            for line in &lines[last_pos.row()..fix.start.row() - 1] {
+                output.push_str(line);
+                output.push('\n');
+            }
+            output.push_str(&lines[fix.start.row() - 1][..fix.start.column() - 1]);
+            output.push_str(&fix.content);
+        } else {
+            output.push_str(
+                &lines[last_pos.row() - 1][last_pos.column() - 1..fix.start.column() - 1],
+            );
+            output.push_str(&fix.content);
+        }
+
+        last_pos = fix.end;
+        fix.applied = true;
+    }
+
+    if last_pos.row() > 0 || last_pos.column() > 0 {
+        output.push_str(&lines[last_pos.row() - 1][last_pos.column() - 1..]);
+        output.push('\n');
+    }
+    for line in &lines[last_pos.row()..] {
+        output.push_str(line);
+        output.push('\n');
+    }
+
+    output
+}
+
+#[cfg(test)]
+mod tests {
+    use anyhow::Result;
+    use rustpython_parser::ast::Location;
+
+    use crate::autofix::fixer::apply_fixes;
+    use crate::checks::Fix;
+
+    #[test]
+    fn empty_file() -> Result<()> {
+        let mut fixes = vec![];
+        let actual = apply_fixes(fixes.iter_mut(), "");
+        let expected = "";
+
+        assert_eq!(actual, expected);
+
+        Ok(())
+    }
+
+    #[test]
+    fn apply_single_replacement() -> Result<()> {
+        let mut fixes = vec![Fix {
+            content: "Bar".to_string(),
+            start: Location::new(1, 9),
+            end: Location::new(1, 15),
+            applied: false,
+        }];
+        let actual = apply_fixes(
+            fixes.iter_mut(),
+            "class A(object):
+        ...
+",
+        );
+
+        let expected = "class A(Bar):
+        ...
+";
+
+        assert_eq!(actual, expected);
+
+        Ok(())
+    }
+
+    #[test]
+    fn apply_single_removal() -> Result<()> {
+        let mut fixes = vec![Fix {
+            content: "".to_string(),
+            start: Location::new(1, 8),
+            end: Location::new(1, 16),
+            applied: false,
+        }];
+        let actual = apply_fixes(
+            fixes.iter_mut(),
+            "class A(object):
+        ...
+",
+        );
+
+        let expected = "class A:
+        ...
+";
+
+        assert_eq!(actual, expected);
+
+        Ok(())
+    }
+
+    #[test]
+    fn apply_double_removal() -> Result<()> {
+        let mut fixes = vec![
+            Fix {
+                content: "".to_string(),
+                start: Location::new(1, 8),
+                end: Location::new(1, 17),
+                applied: false,
+            },
+            Fix {
+                content: "".to_string(),
+                start: Location::new(1, 17),
+                end: Location::new(1, 24),
+                applied: false,
+            },
+        ];
+        let actual = apply_fixes(
+            fixes.iter_mut(),
+            "class A(object, object):
+        ...
+",
+        );
+
+        let expected = "class A:
+        ...
+";
+
+        assert_eq!(actual, expected);
+
+        Ok(())
+    }
+
+    #[test]
+    fn ignore_overlapping_fixes() -> Result<()> {
+        let mut fixes = vec![
+            Fix {
+                content: "".to_string(),
+                start: Location::new(1, 8),
+                end: Location::new(1, 16),
+                applied: false,
+            },
+            Fix {
+                content: "ignored".to_string(),
+                start: Location::new(1, 10),
+                end: Location::new(1, 12),
+                applied: false,
+            },
+        ];
+        let actual = apply_fixes(
+            fixes.iter_mut(),
+            "class A(object):
+    ...
+",
+        );
+
+        let expected = "class A:
+    ...
+";
+
+        assert_eq!(actual, expected);
+
+        Ok(())
+    }
+}
--- a/src/autofix/fixes.rs
+++ b/src/autofix/fixes.rs
@@ -1,8 +1,8 @@
-use crate::ast_ops::SourceCodeLocator;
 use rustpython_parser::ast::{Expr, Keyword, Location};
 use rustpython_parser::lexer;
 use rustpython_parser::token::Tok;

+use crate::ast::operations::SourceCodeLocator;
 use crate::checks::Fix;

 /// Convert a location within a file (relative to `base`) to an absolute position.
--- a/src/cache.rs
+++ b/src/cache.rs
@@ -1,14 +1,16 @@
 use std::collections::hash_map::DefaultHasher;
-use std::fs::Metadata;
+use std::fs::{File, Metadata};
 use std::hash::{Hash, Hasher};
+use std::io::Write;
 use std::path::Path;

-use crate::autofix;
+use anyhow::Result;
 use cacache::Error::EntryNotFound;
 use filetime::FileTime;
 use log::error;
 use serde::{Deserialize, Serialize};

+use crate::autofix::fixer;
 use crate::message::Message;
 use crate::settings::Settings;

@@ -62,7 +64,7 @@ impl From<bool> for Mode {
    fn from(value: bool) -> Self {
        match value {
            true => Mode::ReadWrite,
-            false => Mode::WriteOnly,
+            false => Mode::None,
        }
    }
 }
@@ -71,7 +73,7 @@ fn cache_dir() -> &'static str {
    "./.ruff_cache"
 }

-fn cache_key(path: &Path, settings: &Settings, autofix: &autofix::Mode) -> String {
+fn cache_key(path: &Path, settings: &Settings, autofix: &fixer::Mode) -> String {
    let mut hasher = DefaultHasher::new();
    settings.hash(&mut hasher);
    autofix.hash(&mut hasher);
@@ -83,11 +85,20 @@ fn cache_key(path: &Path, settings: &Settings, autofix: &autofix::Mode) -> Strin
    )
 }

+pub fn init() -> Result<()> {
+    let gitignore_path = Path::new(cache_dir()).join(".gitignore");
+    if gitignore_path.exists() {
+        return Ok(());
+    }
+    let mut file = File::create(gitignore_path)?;
+    file.write_all(b"*").map_err(|e| e.into())
+}
+
 pub fn get(
    path: &Path,
    metadata: &Metadata,
    settings: &Settings,
-    autofix: &autofix::Mode,
+    autofix: &fixer::Mode,
    mode: &Mode,
 ) -> Option<Vec<Message>> {
    if !mode.allow_read() {
@@ -116,7 +127,7 @@ pub fn set(
    path: &Path,
    metadata: &Metadata,
    settings: &Settings,
-    autofix: &autofix::Mode,
+    autofix: &fixer::Mode,
    messages: &[Message],
    mode: &Mode,
 ) {
--- a/src/check_ast.rs
+++ b/src/check_ast.rs
--- a/src/check_lines.rs
+++ b/src/check_lines.rs
@@ -1,11 +1,11 @@
 use rustpython_parser::ast::Location;

-use crate::checks::{Check, CheckKind};
+use crate::checks::{Check, CheckCode, CheckKind};
 use crate::settings::Settings;

 /// Whether the given line is too long and should be reported.
-fn should_enforce_line_length(line: &str, limit: usize) -> bool {
-    if line.len() > limit {
+fn should_enforce_line_length(line: &str, length: usize, limit: usize) -> bool {
+    if length > limit {
        let mut chunks = line.split_whitespace();
        if let (Some(first), Some(_)) = (chunks.next(), chunks.next()) {
            // Do not enforce the line length for commented lines with a single word
@@ -20,7 +20,7 @@ fn should_enforce_line_length(line: &str, limit: usize) -> bool {
 }

 pub fn check_lines(checks: &mut Vec<Check>, contents: &str, settings: &Settings) {
-    let enforce_line_too_long = settings.select.contains(CheckKind::LineTooLong.code());
+    let enforce_line_too_long = settings.select.contains(&CheckCode::E501);

    let mut line_checks = vec![];
    let mut ignored = vec![];
@@ -34,13 +34,16 @@ pub fn check_lines(checks: &mut Vec<Check>, contents: &str, settings: &Settings)
        }

        // Enforce line length.
-        if enforce_line_too_long && should_enforce_line_length(line, settings.line_length) {
-            let check = Check::new(
-                CheckKind::LineTooLong,
-                Location::new(row + 1, settings.line_length + 1),
-            );
-            if !check.is_inline_ignored(line) {
-                line_checks.push(check);
+        if enforce_line_too_long {
+            let line_length = line.len();
+            if should_enforce_line_length(line, line_length, settings.line_length) {
+                let check = Check::new(
+                    CheckKind::LineTooLong(line_length, settings.line_length),
+                    Location::new(row + 1, settings.line_length + 1),
+                );
+                if !check.is_inline_ignored(line) {
+                    line_checks.push(check);
+                }
            }
        }
    }
--- a/src/checks.rs
+++ b/src/checks.rs
@@ -14,16 +14,34 @@ pub enum CheckCode {
    E712,
    E713,
    E714,
+    E721,
+    E722,
    E731,
+    E741,
+    E742,
+    E743,
    E902,
+    E999,
    F401,
    F403,
+    F404,
+    F406,
+    F407,
    F541,
+    F601,
+    F602,
+    F621,
+    F622,
    F631,
+    F632,
+    F633,
    F634,
+    F701,
+    F702,
    F704,
    F706,
    F707,
+    F722,
    F821,
    F822,
    F823,
@@ -45,16 +63,34 @@ impl FromStr for CheckCode {
            "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),
            "F403" => Ok(CheckCode::F403),
+            "F404" => Ok(CheckCode::F404),
+            "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),
@@ -77,16 +113,34 @@ impl CheckCode {
            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::F403 => "F403",
+            CheckCode::F404 => "F404",
+            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",
@@ -98,33 +152,12 @@ impl CheckCode {
        }
    }

-    /// The source for the check (either the AST, or the physical lines).
+    /// The source for the check (either the AST, the filesystem, or the physical lines).
    pub fn lint_source(&self) -> &'static LintSource {
        match self {
-            CheckCode::E402 => &LintSource::AST,
            CheckCode::E501 => &LintSource::Lines,
-            CheckCode::E711 => &LintSource::AST,
-            CheckCode::E712 => &LintSource::AST,
-            CheckCode::E713 => &LintSource::AST,
-            CheckCode::E714 => &LintSource::AST,
-            CheckCode::E731 => &LintSource::AST,
-            CheckCode::E902 => &LintSource::FileSystem,
-            CheckCode::F401 => &LintSource::AST,
-            CheckCode::F403 => &LintSource::AST,
-            CheckCode::F541 => &LintSource::AST,
-            CheckCode::F631 => &LintSource::AST,
-            CheckCode::F634 => &LintSource::AST,
-            CheckCode::F704 => &LintSource::AST,
-            CheckCode::F706 => &LintSource::AST,
-            CheckCode::F707 => &LintSource::AST,
-            CheckCode::F821 => &LintSource::AST,
-            CheckCode::F822 => &LintSource::AST,
-            CheckCode::F823 => &LintSource::AST,
-            CheckCode::F831 => &LintSource::AST,
-            CheckCode::F841 => &LintSource::AST,
-            CheckCode::F901 => &LintSource::AST,
-            CheckCode::R001 => &LintSource::AST,
-            CheckCode::R002 => &LintSource::AST,
+            CheckCode::E902 | CheckCode::E999 => &LintSource::FileSystem,
+            _ => &LintSource::AST,
        }
    }
 }
@@ -144,23 +177,41 @@ pub enum RejectedCmpop {

 #[derive(Debug, PartialEq, Eq, Serialize, Deserialize)]
 pub enum CheckKind {
+    AmbiguousClassName(String),
+    AmbiguousFunctionName(String),
+    AmbiguousVariableName(String),
    AssertTuple,
+    BreakOutsideLoop,
+    ContinueOutsideLoop,
    DefaultExceptNotLast,
    DoNotAssignLambda,
+    DoNotUseBareExcept,
    DuplicateArgumentName,
+    ForwardAnnotationSyntaxError(String),
    FStringMissingPlaceholders,
+    FutureFeatureNotDefined(String),
    IOError(String),
    IfTuple,
-    ImportStarUsage,
-    LineTooLong,
+    ImportStarNotPermitted(String),
+    ImportStarUsage(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),
@@ -174,23 +225,43 @@ 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::ImportStarUsage => "ImportStarUsage",
-            CheckKind::LineTooLong => "LineTooLong",
-            CheckKind::DoNotAssignLambda => "DoNotAssignLambda",
+            CheckKind::ImportStarNotPermitted(_) => "ImportStarNotPermitted",
+            CheckKind::ImportStarUsage(_) => "ImportStarUsage",
+            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",
@@ -204,23 +275,41 @@ impl CheckKind {
    /// A four-letter shorthand code for the check.
    pub fn code(&self) -> &'static CheckCode {
        match self {
+            CheckKind::AmbiguousClassName(_) => &CheckCode::E742,
+            CheckKind::AmbiguousFunctionName(_) => &CheckCode::E743,
+            CheckKind::AmbiguousVariableName(_) => &CheckCode::E741,
            CheckKind::AssertTuple => &CheckCode::F631,
+            CheckKind::BreakOutsideLoop => &CheckCode::F701,
+            CheckKind::ContinueOutsideLoop => &CheckCode::F702,
            CheckKind::DefaultExceptNotLast => &CheckCode::F707,
+            CheckKind::DoNotAssignLambda => &CheckCode::E731,
+            CheckKind::DoNotUseBareExcept => &CheckCode::E722,
            CheckKind::DuplicateArgumentName => &CheckCode::F831,
            CheckKind::FStringMissingPlaceholders => &CheckCode::F541,
+            CheckKind::ForwardAnnotationSyntaxError(_) => &CheckCode::F722,
+            CheckKind::FutureFeatureNotDefined(_) => &CheckCode::F407,
            CheckKind::IOError(_) => &CheckCode::E902,
            CheckKind::IfTuple => &CheckCode::F634,
-            CheckKind::ImportStarUsage => &CheckCode::F403,
-            CheckKind::LineTooLong => &CheckCode::E501,
-            CheckKind::DoNotAssignLambda => &CheckCode::E731,
+            CheckKind::ImportStarNotPermitted(_) => &CheckCode::F406,
+            CheckKind::ImportStarUsage(_) => &CheckCode::F403,
+            CheckKind::InvalidPrintSyntax => &CheckCode::F633,
+            CheckKind::IsLiteral => &CheckCode::F632,
+            CheckKind::LateFutureImport => &CheckCode::F404,
+            CheckKind::LineTooLong(_, _) => &CheckCode::E501,
            CheckKind::ModuleImportNotAtTopOfFile => &CheckCode::E402,
+            CheckKind::MultiValueRepeatedKeyLiteral => &CheckCode::F601,
+            CheckKind::MultiValueRepeatedKeyVariable(_) => &CheckCode::F602,
            CheckKind::NoAssertEquals => &CheckCode::R002,
            CheckKind::NoneComparison(_) => &CheckCode::E711,
            CheckKind::NotInTest => &CheckCode::E713,
            CheckKind::NotIsTest => &CheckCode::E714,
            CheckKind::RaiseNotImplemented => &CheckCode::F901,
            CheckKind::ReturnOutsideFunction => &CheckCode::F706,
+            CheckKind::SyntaxError(_) => &CheckCode::E999,
+            CheckKind::TooManyExpressionsInStarredAssignment => &CheckCode::F621,
            CheckKind::TrueFalseComparison(_, _) => &CheckCode::E712,
+            CheckKind::TwoStarredExpressions => &CheckCode::F622,
+            CheckKind::TypeComparison => &CheckCode::E721,
            CheckKind::UndefinedExport(_) => &CheckCode::F822,
            CheckKind::UndefinedLocal(_) => &CheckCode::F823,
            CheckKind::UndefinedName(_) => &CheckCode::F821,
@@ -234,30 +323,66 @@ impl CheckKind {
    /// The body text for the check.
    pub fn body(&self) -> String {
        match self {
+            CheckKind::AmbiguousClassName(name) => {
+                format!("ambiguous class name '{}'", name)
+            }
+            CheckKind::AmbiguousFunctionName(name) => {
+                format!("ambiguous function name '{}'", name)
+            }
+            CheckKind::AmbiguousVariableName(name) => {
+                format!("ambiguous variable name '{}'", name)
+            }
            CheckKind::AssertTuple => {
                "Assert test is a non-empty tuple, which is always `True`".to_string()
            }
+            CheckKind::BreakOutsideLoop => "`break` outside loop".to_string(),
+            CheckKind::ContinueOutsideLoop => "`continue` not properly in loop".to_string(),
            CheckKind::DefaultExceptNotLast => {
                "an `except:` block as not the last exception handler".to_string()
            }
+            CheckKind::DoNotAssignLambda => {
+                "Do not assign a lambda expression, use a def".to_string()
+            }
+            CheckKind::DoNotUseBareExcept => "Do not use bare `except`".to_string(),
            CheckKind::DuplicateArgumentName => {
                "Duplicate argument name in function definition".to_string()
            }
+            CheckKind::ForwardAnnotationSyntaxError(body) => {
+                format!("syntax error in forward annotation '{body}'")
+            }
            CheckKind::FStringMissingPlaceholders => {
                "f-string without any placeholders".to_string()
            }
+            CheckKind::FutureFeatureNotDefined(name) => {
+                format!("future feature '{name}' is not defined")
+            }
            CheckKind::IOError(name) => {
                format!("No such file or directory: `{name}`")
            }
            CheckKind::IfTuple => "If test is a tuple, which is always `True`".to_string(),
-            CheckKind::ImportStarUsage => "Unable to detect undefined names".to_string(),
-            CheckKind::LineTooLong => "Line too long".to_string(),
-            CheckKind::DoNotAssignLambda => {
-                "Do not assign a lambda expression, use a def".to_string()
+            CheckKind::InvalidPrintSyntax => "use of >> is invalid with print function".to_string(),
+            CheckKind::ImportStarNotPermitted(name) => {
+                format!("`from {name} import *` only allowed at module level")
+            }
+            CheckKind::ImportStarUsage(name) => {
+                format!("`from {name} import *` used; unable to detect undefined names")
+            }
+            CheckKind::IsLiteral => "use ==/!= to compare constant literals".to_string(),
+            CheckKind::LateFutureImport => {
+                "from __future__ imports must occur at the beginning of the file".to_string()
+            }
+            CheckKind::LineTooLong(length, limit) => {
+                format!("Line too long ({length} > {limit} characters)")
            }
            CheckKind::ModuleImportNotAtTopOfFile => {
                "Module level import not at top of file".to_string()
            }
+            CheckKind::MultiValueRepeatedKeyLiteral => {
+                "Dictionary key literal repeated".to_string()
+            }
+            CheckKind::MultiValueRepeatedKeyVariable(name) => {
+                format!("Dictionary key `{name}` repeated")
+            }
            CheckKind::NoAssertEquals => {
                "`assertEquals` is deprecated, use `assertEqual` instead".to_string()
            }
@@ -275,6 +400,10 @@ impl CheckKind {
            CheckKind::ReturnOutsideFunction => {
                "a `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::TrueFalseComparison(value, op) => match *value {
                true => match op {
                    RejectedCmpop::Eq => {
@@ -293,15 +422,17 @@ impl CheckKind {
                    }
                },
            },
+            CheckKind::TwoStarredExpressions => "two starred expressions in assignment".to_string(),
+            CheckKind::TypeComparison => "do not compare types, use `isinstance()`".to_string(),
            CheckKind::UndefinedExport(name) => {
                format!("Undefined name `{name}` in `__all__`")
            }
-            CheckKind::UndefinedName(name) => {
-                format!("Undefined name `{name}`")
-            }
            CheckKind::UndefinedLocal(name) => {
                format!("Local variable `{name}` referenced before assignment")
            }
+            CheckKind::UndefinedName(name) => {
+                format!("Undefined name `{name}`")
+            }
            CheckKind::UnusedImport(name) => format!("`{name}` imported but unused"),
            CheckKind::UnusedVariable(name) => {
                format!("Local variable `{name}` is assigned to but never used")
@@ -317,32 +448,10 @@ impl CheckKind {

    /// Whether the check kind is (potentially) fixable.
    pub fn fixable(&self) -> bool {
-        match self {
-            CheckKind::AssertTuple => false,
-            CheckKind::DefaultExceptNotLast => false,
-            CheckKind::DuplicateArgumentName => false,
-            CheckKind::FStringMissingPlaceholders => false,
-            CheckKind::IOError(_) => false,
-            CheckKind::IfTuple => false,
-            CheckKind::ImportStarUsage => false,
-            CheckKind::DoNotAssignLambda => false,
-            CheckKind::LineTooLong => false,
-            CheckKind::ModuleImportNotAtTopOfFile => false,
-            CheckKind::NoAssertEquals => true,
-            CheckKind::NotInTest => false,
-            CheckKind::NotIsTest => false,
-            CheckKind::NoneComparison(_) => false,
-            CheckKind::RaiseNotImplemented => false,
-            CheckKind::ReturnOutsideFunction => false,
-            CheckKind::TrueFalseComparison(_, _) => false,
-            CheckKind::UndefinedExport(_) => false,
-            CheckKind::UndefinedLocal(_) => false,
-            CheckKind::UndefinedName(_) => false,
-            CheckKind::UnusedImport(_) => false,
-            CheckKind::UnusedVariable(_) => false,
-            CheckKind::UselessObjectInheritance(_) => true,
-            CheckKind::YieldOutsideFunction => false,
-        }
+        matches!(
+            self,
+            CheckKind::NoAssertEquals | CheckKind::UselessObjectInheritance(_)
+        )
    }
 }

--- a/src/fs.rs
+++ b/src/fs.rs
@@ -1,37 +1,86 @@
+use std::env;
 use std::fs::File;
 use std::io::{BufReader, Read};
 use std::path::{Path, PathBuf};

 use anyhow::Result;
 use glob::Pattern;
+use log::debug;
+use path_absolutize::Absolutize;
 use walkdir::{DirEntry, WalkDir};

-fn is_not_hidden(entry: &DirEntry) -> bool {
-    entry
-        .file_name()
-        .to_str()
-        .map(|s| (entry.depth() == 0 || !s.starts_with('.')))
-        .unwrap_or(false)
+fn is_excluded(path: &Path, exclude: &[Pattern]) -> bool {
+    // Check the basename.
+    if let Some(file_name) = path.file_name() {
+        if let Some(file_name) = file_name.to_str() {
+            for pattern in exclude {
+                if pattern.matches(file_name) {
+                    return true;
+                }
+            }
+        }
+    }
+
+    // Check the complete path.
+    if let Some(file_name) = path.to_str() {
+        for pattern in exclude {
+            if pattern.matches(file_name) {
+                return true;
+            }
+        }
+    }
+
+    false
 }

-fn is_not_excluded(entry: &DirEntry, exclude: &[Pattern]) -> bool {
-    entry
-        .path()
-        .to_str()
-        .map(|s| !exclude.iter().any(|pattern| pattern.matches(s)))
-        .unwrap_or(false)
+fn is_included(path: &Path) -> bool {
+    let file_name = path.to_string_lossy();
+    file_name.ends_with(".py") || file_name.ends_with(".pyi")
 }

 pub fn iter_python_files<'a>(
    path: &'a PathBuf,
    exclude: &'a [Pattern],
+    extend_exclude: &'a [Pattern],
 ) -> impl Iterator<Item = DirEntry> + 'a {
-    WalkDir::new(path)
+    WalkDir::new(normalize_path(path))
        .follow_links(true)
        .into_iter()
-        .filter_entry(|entry| is_not_hidden(entry) && is_not_excluded(entry, exclude))
+        .filter_entry(|entry| {
+            if exclude.is_empty() && extend_exclude.is_empty() {
+                return true;
+            }
+
+            let path = entry.path();
+            if is_excluded(path, exclude) {
+                debug!("Ignored path via `exclude`: {:?}", path);
+                false
+            } else if is_excluded(path, extend_exclude) {
+                debug!("Ignored path via `extend-exclude`: {:?}", path);
+                false
+            } else {
+                true
+            }
+        })
        .filter_map(|entry| entry.ok())
-        .filter(|entry| entry.path().to_string_lossy().ends_with(".py"))
+        .filter(|entry| {
+            let path = entry.path();
+            is_included(path)
+        })
+}
+
+pub fn normalize_path(path: &PathBuf) -> PathBuf {
+    if path == Path::new(".") || path == Path::new("..") {
+        return path.clone();
+    }
+    if let Ok(path) = path.absolutize() {
+        if let Ok(root) = env::current_dir() {
+            if let Ok(path) = path.strip_prefix(root) {
+                return Path::new(".").join(path);
+            }
+        }
+    }
+    path.clone()
 }

 pub fn read_file(path: &Path) -> Result<String> {
@@ -41,3 +90,58 @@ pub fn read_file(path: &Path) -> Result<String> {
    buf_reader.read_to_string(&mut contents)?;
    Ok(contents)
 }
+
+#[cfg(test)]
+mod tests {
+    use std::path::Path;
+
+    use glob::Pattern;
+
+    use crate::fs::{is_excluded, is_included};
+
+    #[test]
+    fn inclusions() {
+        let path = Path::new("foo/bar/baz.py");
+        assert!(is_included(path));
+
+        let path = Path::new("foo/bar/baz.pyi");
+        assert!(is_included(path));
+
+        let path = Path::new("foo/bar/baz.js");
+        assert!(!is_included(path));
+
+        let path = Path::new("foo/bar/baz");
+        assert!(!is_included(path));
+    }
+
+    #[test]
+    fn exclusions() {
+        let path = Path::new("foo");
+        let exclude = vec![Pattern::new("foo").unwrap()];
+        assert!(is_excluded(path, &exclude));
+
+        let path = Path::new("foo/bar");
+        let exclude = vec![Pattern::new("bar").unwrap()];
+        assert!(is_excluded(path, &exclude));
+
+        let path = Path::new("foo/bar/baz.py");
+        let exclude = vec![Pattern::new("baz.py").unwrap()];
+        assert!(is_excluded(path, &exclude));
+
+        let path = Path::new("foo/bar");
+        let exclude = vec![Pattern::new("foo/bar").unwrap()];
+        assert!(is_excluded(path, &exclude));
+
+        let path = Path::new("foo/bar/baz.py");
+        let exclude = vec![Pattern::new("foo/bar/baz.py").unwrap()];
+        assert!(is_excluded(path, &exclude));
+
+        let path = Path::new("foo/bar/baz.py");
+        let exclude = vec![Pattern::new("foo/bar/*.py").unwrap()];
+        assert!(is_excluded(path, &exclude));
+
+        let path = Path::new("foo/bar/baz.py");
+        let exclude = vec![Pattern::new("baz").unwrap()];
+        assert!(!is_excluded(path, &exclude));
+    }
+}
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1,17 +1,16 @@
 extern crate core;

-mod ast_ops;
+mod ast;
 mod autofix;
-mod builtins;
-mod cache;
+pub mod cache;
 pub mod check_ast;
 mod check_lines;
 pub mod checks;
-mod fixer;
 pub mod fs;
 pub mod linter;
 pub mod logging;
 pub mod message;
+pub mod printer;
 mod pyproject;
+mod python;
 pub mod settings;
-mod visitor;
--- a/src/linter.rs
+++ b/src/linter.rs
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,4 +1,4 @@
-use std::path::{Path, PathBuf};
+use std::path::PathBuf;
 use std::process::ExitCode;
 use std::sync::mpsc::channel;
 use std::time::Instant;
@@ -6,17 +6,20 @@ use std::time::Instant;
 use anyhow::Result;
 use clap::{Parser, ValueHint};
 use colored::Colorize;
+use glob::Pattern;
 use log::{debug, error};
 use notify::{raw_watcher, RecursiveMode, Watcher};
 use rayon::prelude::*;
 use walkdir::DirEntry;

+use ::ruff::cache;
 use ::ruff::checks::CheckCode;
 use ::ruff::checks::CheckKind;
 use ::ruff::fs::iter_python_files;
 use ::ruff::linter::lint_path;
 use ::ruff::logging::set_up_logging;
 use ::ruff::message::Message;
+use ::ruff::printer::{Printer, SerializationFormat};
 use ::ruff::settings::Settings;
 use ::ruff::tell_user;

@@ -47,12 +50,21 @@ struct Cli {
    /// Disable cache reads.
    #[clap(short, long, action)]
    no_cache: bool,
-    /// Comma-separated list of error codes to enable.
+    /// List of error codes to enable.
    #[clap(long, multiple = true)]
    select: Vec<CheckCode>,
-    /// Comma-separated list of error codes to ignore.
+    /// List of error codes to ignore.
    #[clap(long, multiple = true)]
    ignore: Vec<CheckCode>,
+    /// List of paths, used to exclude files and/or directories from checks.
+    #[clap(long, multiple = true)]
+    exclude: Vec<Pattern>,
+    /// Like --exclude, but adds additional files and directories on top of the excluded ones.
+    #[clap(long, multiple = true)]
+    extend_exclude: Vec<Pattern>,
+    /// Output serialization format for error messages.
+    #[clap(long, arg_enum, default_value_t=SerializationFormat::Text)]
+    format: SerializationFormat,
 }

 #[cfg(feature = "update-informer")]
@@ -89,7 +101,7 @@ fn run_once(
    let start = Instant::now();
    let paths: Vec<DirEntry> = files
        .iter()
-        .flat_map(|path| iter_python_files(path, &settings.exclude))
+        .flat_map(|path| iter_python_files(path, &settings.exclude, &settings.extend_exclude))
        .collect();
    let duration = start.elapsed();
    debug!("Identified files to lint in: {:?}", duration);
@@ -99,8 +111,17 @@ fn run_once(
        .par_iter()
        .map(|entry| {
            lint_path(entry.path(), settings, &cache.into(), &autofix.into()).unwrap_or_else(|e| {
-                error!("Failed to check {}: {e:?}", entry.path().to_string_lossy());
-                vec![]
+                if settings.select.contains(&CheckCode::E999) {
+                    vec![Message {
+                        kind: CheckKind::SyntaxError(e.to_string()),
+                        fixed: false,
+                        location: Default::default(),
+                        filename: entry.path().to_string_lossy().to_string(),
+                    }]
+                } else {
+                    error!("Failed to check {}: {e:?}", entry.path().to_string_lossy());
+                    vec![]
+                }
            })
        })
        .flatten()
@@ -126,81 +147,46 @@ fn run_once(
    Ok(messages)
 }

-fn report_once(messages: &[Message]) -> Result<()> {
-    let (fixed, outstanding): (Vec<&Message>, Vec<&Message>) =
-        messages.iter().partition(|message| message.fixed);
-    let num_fixable = outstanding
-        .iter()
-        .filter(|message| message.kind.fixable())
-        .count();
-
-    if !outstanding.is_empty() {
-        for message in &outstanding {
-            println!("{}", message);
-        }
-        println!();
-    }
-
-    if !fixed.is_empty() {
-        println!(
-            "Found {} error(s) ({} fixed).",
-            outstanding.len(),
-            fixed.len()
-        );
-    } else {
-        println!("Found {} error(s).", outstanding.len());
-    }
-
-    if num_fixable > 0 {
-        println!("{num_fixable} potentially fixable with the --fix option.");
-    }
-
-    Ok(())
-}
-
-fn report_continuously(messages: &[Message]) -> Result<()> {
-    tell_user!(
-        "Found {} error(s). Watching for file changes.",
-        messages.len(),
-    );
-
-    if !messages.is_empty() {
-        println!();
-        for message in messages {
-            println!("{}", message);
-        }
-    }
-
-    Ok(())
-}
-
 fn inner_main() -> Result<ExitCode> {
    let cli = Cli::parse();

    set_up_logging(cli.verbose)?;

-    // TODO(charlie): Can we avoid this cast?
-    let paths: Vec<&Path> = cli.files.iter().map(PathBuf::as_path).collect();
-    let mut settings = Settings::from_paths(paths)?;
+    let mut settings = Settings::from_paths(&cli.files);
+
+    let mut printer = Printer::new(cli.format);
+
    if !cli.select.is_empty() {
        settings.select(cli.select);
    }
    if !cli.ignore.is_empty() {
        settings.ignore(&cli.ignore);
    }
+    if !cli.exclude.is_empty() {
+        settings.exclude = cli.exclude;
+    }
+    if !cli.extend_exclude.is_empty() {
+        settings.extend_exclude = cli.extend_exclude;
+    }
+
+    cache::init()?;

    if cli.watch {
        if cli.fix {
-            println!("Warning: --fix is not enabled in watch mode.")
+            println!("Warning: --fix is not enabled in watch mode.");
+        }
+
+        if cli.format != SerializationFormat::Text {
+            println!("Warning: --format 'text' is used in watch mode.");
        }

        // Perform an initial run instantly.
-        clearscreen::clear()?;
+        printer.clear_screen()?;
        tell_user!("Starting linter in watch mode...\n");

        let messages = run_once(&cli.files, &settings, !cli.no_cache, false)?;
        if !cli.quiet {
-            report_continuously(&messages)?;
+            printer.write_continuously(&messages)?;
        }

        // Configure the file watcher.
@@ -215,12 +201,12 @@ fn inner_main() -> Result<ExitCode> {
                Ok(e) => {
                    if let Some(path) = e.path {
                        if path.to_string_lossy().ends_with(".py") {
-                            clearscreen::clear()?;
+                            printer.clear_screen()?;
                            tell_user!("File change detected...\n");

                            let messages = run_once(&cli.files, &settings, !cli.no_cache, false)?;
                            if !cli.quiet {
-                                report_continuously(&messages)?;
+                                printer.write_continuously(&messages)?;
                            }
                        }
                    }
@@ -231,7 +217,7 @@ fn inner_main() -> Result<ExitCode> {
    } else {
        let messages = run_once(&cli.files, &settings, !cli.no_cache, cli.fix)?;
        if !cli.quiet {
-            report_once(&messages)?;
+            printer.write_once(&messages)?;
        }

        #[cfg(feature = "update-informer")]
--- a/src/message.rs
+++ b/src/message.rs
@@ -20,7 +20,7 @@ impl Ord for Message {
        (&self.filename, self.location.row(), self.location.column()).cmp(&(
            &other.filename,
            other.location.row(),
-            self.location.column(),
+            other.location.column(),
        ))
    }
 }
--- a/src/printer.rs
+++ b/src/printer.rs
@@ -0,0 +1,80 @@
+use colored::Colorize;
+
+use anyhow::Result;
+use clap::ValueEnum;
+
+use crate::message::Message;
+use crate::tell_user;
+
+#[derive(Clone, Copy, ValueEnum, PartialEq, Eq, Debug)]
+pub enum SerializationFormat {
+    Text,
+    Json,
+}
+
+pub struct Printer {
+    format: SerializationFormat,
+}
+
+impl Printer {
+    pub fn new(format: SerializationFormat) -> Self {
+        Self { format }
+    }
+
+    pub fn write_once(&mut self, messages: &[Message]) -> Result<()> {
+        let (fixed, outstanding): (Vec<&Message>, Vec<&Message>) =
+            messages.iter().partition(|message| message.fixed);
+        let num_fixable = outstanding
+            .iter()
+            .filter(|message| message.kind.fixable())
+            .count();
+
+        match self.format {
+            SerializationFormat::Json => {
+                println!("{}", serde_json::to_string_pretty(&messages)?)
+            }
+            SerializationFormat::Text => {
+                if !fixed.is_empty() {
+                    println!(
+                        "Found {} error(s) ({} fixed).",
+                        outstanding.len(),
+                        fixed.len()
+                    )
+                } else {
+                    println!("Found {} error(s).", outstanding.len())
+                }
+
+                for message in outstanding {
+                    println!("{}", message)
+                }
+
+                if num_fixable > 0 {
+                    println!("{num_fixable} potentially fixable with the --fix option.")
+                }
+            }
+        }
+
+        Ok(())
+    }
+
+    pub fn write_continuously(&mut self, messages: &[Message]) -> Result<()> {
+        tell_user!(
+            "Found {} error(s). Watching for file changes.",
+            messages.len(),
+        );
+
+        if !messages.is_empty() {
+            println!();
+            for message in messages {
+                println!("{}", message)
+            }
+        }
+
+        Ok(())
+    }
+
+    pub fn clear_screen(&mut self) -> Result<()> {
+        clearscreen::clear()?;
+        Ok(())
+    }
+}
--- a/src/pyproject.rs
+++ b/src/pyproject.rs
@@ -1,4 +1,3 @@
-use std::collections::BTreeSet;
 use std::path::{Path, PathBuf};

 use anyhow::Result;
@@ -9,29 +8,26 @@ use serde::Deserialize;
 use crate::checks::CheckCode;
 use crate::fs;

-pub fn load_config<'a>(paths: impl IntoIterator<Item = &'a Path>) -> Result<(PathBuf, Config)> {
+pub fn load_config(paths: &[PathBuf]) -> Config {
    match find_project_root(paths) {
        Some(project_root) => match find_pyproject_toml(&project_root) {
            Some(path) => {
-                debug!("Found pyproject.toml at: {}", path.to_string_lossy());
+                debug!("Found pyproject.toml at: {:?}", path);
                match parse_pyproject_toml(&path) {
-                    Ok(pyproject) => {
-                        let config = pyproject
-                            .tool
-                            .and_then(|tool| tool.ruff)
-                            .unwrap_or_default();
-                        Ok((project_root, config))
-                    }
+                    Ok(pyproject) => pyproject
+                        .tool
+                        .and_then(|tool| tool.ruff)
+                        .unwrap_or_default(),
                    Err(e) => {
                        println!("Failed to load pyproject.toml: {:?}", e);
                        println!("Falling back to default configuration...");
-                        Ok(Default::default())
+                        Default::default()
                    }
                }
            }
-            None => Ok(Default::default()),
+            None => Default::default(),
        },
-        None => Ok(Default::default()),
+        None => Default::default(),
    }
 }

@@ -40,7 +36,9 @@ pub fn load_config<'a>(paths: impl IntoIterator<Item = &'a Path>) -> Result<(Pat
 pub struct Config {
    pub line_length: Option<usize>,
    pub exclude: Option<Vec<PathBuf>>,
-    pub select: Option<BTreeSet<CheckCode>>,
+    pub extend_exclude: Option<Vec<PathBuf>>,
+    pub select: Option<Vec<CheckCode>>,
+    pub ignore: Option<Vec<CheckCode>>,
 }

 #[derive(Debug, PartialEq, Eq, Deserialize)]
@@ -70,8 +68,8 @@ fn find_user_pyproject_toml() -> Option<PathBuf> {
    dirs::home_dir().map(|path| path.join(".ruff"))
 }

-fn find_project_root<'a>(sources: impl IntoIterator<Item = &'a Path>) -> Option<PathBuf> {
-    if let Some(prefix) = common_path_all(sources) {
+fn find_project_root(sources: &[PathBuf]) -> Option<PathBuf> {
+    if let Some(prefix) = common_path_all(sources.iter().map(PathBuf::as_path)) {
        for directory in prefix.ancestors() {
            if directory.join(".git").is_dir() {
                return Some(directory.to_path_buf());
@@ -90,8 +88,7 @@ fn find_project_root<'a>(sources: impl IntoIterator<Item = &'a Path>) -> Option<

 #[cfg(test)]
 mod tests {
-    use std::collections::BTreeSet;
-    use std::path::Path;
+    use std::path::{Path, PathBuf};

    use anyhow::Result;

@@ -124,7 +121,9 @@ mod tests {
                ruff: Some(Config {
                    line_length: None,
                    exclude: None,
+                    extend_exclude: None,
                    select: None,
+                    ignore: None,
                })
            })
        );
@@ -142,7 +141,9 @@ line-length = 79
                ruff: Some(Config {
                    line_length: Some(79),
                    exclude: None,
+                    extend_exclude: None,
                    select: None,
+                    ignore: None,
                })
            })
        );
@@ -160,7 +161,9 @@ exclude = ["foo.py"]
                ruff: Some(Config {
                    line_length: None,
                    exclude: Some(vec![Path::new("foo.py").to_path_buf()]),
+                    extend_exclude: None,
                    select: None,
+                    ignore: None,
                })
            })
        );
@@ -178,7 +181,29 @@ select = ["E501"]
                ruff: Some(Config {
                    line_length: None,
                    exclude: None,
-                    select: Some(BTreeSet::from([CheckCode::E501])),
+                    extend_exclude: None,
+                    select: Some(vec![CheckCode::E501]),
+                    ignore: None,
+                })
+            })
+        );
+
+        let pyproject: PyProject = toml::from_str(
+            r#"
+[tool.black]
+[tool.ruff]
+ignore = ["E501"]
+"#,
+        )?;
+        assert_eq!(
+            pyproject.tool,
+            Some(Tools {
+                ruff: Some(Config {
+                    line_length: None,
+                    exclude: None,
+                    extend_exclude: None,
+                    select: None,
+                    ignore: Some(vec![CheckCode::E501]),
                })
            })
        );
@@ -216,8 +241,9 @@ other-attribute = 1

    #[test]
    fn find_and_parse_pyproject_toml() -> Result<()> {
-        let project_root = find_project_root([Path::new("resources/test/fixtures/__init__.py")])
-            .expect("Unable to find project root.");
+        let project_root =
+            find_project_root(&[PathBuf::from("resources/test/fixtures/__init__.py")])
+                .expect("Unable to find project root.");
        assert_eq!(project_root, Path::new("resources/test/fixtures"));

        let path = find_pyproject_toml(&project_root).expect("Unable to find pyproject.toml.");
@@ -232,27 +258,47 @@ other-attribute = 1
            config,
            Config {
                line_length: Some(88),
-                exclude: Some(vec![
+                exclude: None,
+                extend_exclude: Some(vec![
                    Path::new("excluded.py").to_path_buf(),
-                    Path::new("**/migrations").to_path_buf()
+                    Path::new("migrations").to_path_buf(),
+                    Path::new("./resources/test/fixtures/directory/also_excluded.py").to_path_buf()
                ]),
-                select: Some(BTreeSet::from([
+                select: Some(vec![
                    CheckCode::E402,
                    CheckCode::E501,
                    CheckCode::E711,
                    CheckCode::E712,
                    CheckCode::E713,
                    CheckCode::E714,
+                    CheckCode::E721,
+                    CheckCode::E722,
                    CheckCode::E731,
+                    CheckCode::E741,
+                    CheckCode::E742,
+                    CheckCode::E743,
                    CheckCode::E902,
+                    CheckCode::E999,
                    CheckCode::F401,
                    CheckCode::F403,
+                    CheckCode::F404,
+                    CheckCode::F406,
+                    CheckCode::F407,
                    CheckCode::F541,
+                    CheckCode::F601,
+                    CheckCode::F602,
+                    CheckCode::F621,
+                    CheckCode::F622,
                    CheckCode::F631,
+                    CheckCode::F632,
+                    CheckCode::F633,
                    CheckCode::F634,
+                    CheckCode::F701,
+                    CheckCode::F702,
                    CheckCode::F704,
                    CheckCode::F706,
                    CheckCode::F707,
+                    CheckCode::F722,
                    CheckCode::F821,
                    CheckCode::F822,
                    CheckCode::F823,
@@ -261,7 +307,8 @@ other-attribute = 1
                    CheckCode::F901,
                    CheckCode::R001,
                    CheckCode::R002,
-                ])),
+                ]),
+                ignore: None,
            }
        );

--- a/src/python.rs
+++ b/src/python.rs
@@ -0,0 +1,3 @@
+pub mod builtins;
+pub mod future;
+pub mod typing;
--- a/src/python/builtins.rs
+++ b/src/python/builtins.rs
@@ -156,8 +156,8 @@ pub const BUILTINS: &[&str] = &[
 // Globally defined names which are not attributes of the builtins module, or are only present on
 // some platforms.
 pub const MAGIC_GLOBALS: &[&str] = &[
-    "__file__",
-    "__builtins__",
-    "__annotations__",
    "WindowsError",
+    "__annotations__",
+    "__builtins__",
+    "__file__",
 ];
--- a/src/python/future.rs
+++ b/src/python/future.rs
@@ -0,0 +1,13 @@
+/// A copy of `__future__.all_feature_names`.
+pub const ALL_FEATURE_NAMES: &[&str] = &[
+    "nested_scopes",
+    "generators",
+    "division",
+    "absolute_import",
+    "with_statement",
+    "print_function",
+    "unicode_literals",
+    "barry_as_FLUFL",
+    "generator_stop",
+    "annotations",
+];
--- a/src/python/typing.rs
+++ b/src/python/typing.rs
@@ -0,0 +1,88 @@
+use once_cell::sync::Lazy;
+use std::collections::BTreeSet;
+
+static ANNOTATED_SUBSCRIPTS: Lazy<BTreeSet<&'static str>> = Lazy::new(|| {
+    BTreeSet::from([
+        "AbstractAsyncContextManager",
+        "AbstractContextManager",
+        "AbstractSet",
+        "AsyncContextManager",
+        "AsyncGenerator",
+        "AsyncIterable",
+        "AsyncIterator",
+        "Awaitable",
+        "BinaryIO",
+        "BsdDbShelf",
+        "ByteString",
+        "Callable",
+        "ChainMap",
+        "ClassVar",
+        "Collection",
+        "Concatenate",
+        "Container",
+        "ContextManager",
+        "Coroutine",
+        "Counter",
+        "Counter",
+        "DbfilenameShelf",
+        "DefaultDict",
+        "Deque",
+        "Dict",
+        "Field",
+        "Final",
+        "FrozenSet",
+        "Generator",
+        "Iterator",
+        "Generic",
+        "IO",
+        "ItemsView",
+        "Iterable",
+        "Iterator",
+        "KeysView",
+        "LifoQueue",
+        "List",
+        "Mapping",
+        "MappingProxyType",
+        "MappingView",
+        "Match",
+        "MutableMapping",
+        "MutableSequence",
+        "MutableSet",
+        "Optional",
+        "OrderedDict",
+        "PathLike",
+        "Pattern",
+        "PriorityQueue",
+        "Protocol",
+        "Queue",
+        "Reversible",
+        "Sequence",
+        "Set",
+        "Shelf",
+        "SimpleQueue",
+        "TextIO",
+        "Tuple",
+        "Type",
+        "TypeGuard",
+        "Union",
+        "ValuesView",
+        "WeakKeyDictionary",
+        "WeakMethod",
+        "WeakSet",
+        "WeakValueDictionary",
+        "cached_property",
+        "defaultdict",
+        "deque",
+        "dict",
+        "frozenset",
+        "list",
+        "partialmethod",
+        "set",
+        "tuple",
+        "type",
+    ])
+});
+
+pub fn is_annotated_subscript(name: &str) -> bool {
+    ANNOTATED_SUBSCRIPTS.contains(name)
+}
--- a/src/settings.rs
+++ b/src/settings.rs
@@ -1,9 +1,9 @@
 use std::collections::BTreeSet;
 use std::hash::{Hash, Hasher};
-use std::path::Path;
+use std::path::PathBuf;

-use anyhow::Result;
 use glob::Pattern;
+use once_cell::sync::Lazy;

 use crate::checks::CheckCode;
 use crate::pyproject::load_config;
@@ -12,6 +12,7 @@ use crate::pyproject::load_config;
 pub struct Settings {
    pub line_length: usize,
    pub exclude: Vec<Pattern>,
+    pub extend_exclude: Vec<Pattern>,
    pub select: BTreeSet<CheckCode>,
 }

@@ -24,42 +25,92 @@ impl Hash for Settings {
    }
 }

+static DEFAULT_EXCLUDE: Lazy<Vec<Pattern>> = Lazy::new(|| {
+    vec![
+        Pattern::new(".bzr").unwrap(),
+        Pattern::new(".direnv").unwrap(),
+        Pattern::new(".eggs").unwrap(),
+        Pattern::new(".git").unwrap(),
+        Pattern::new(".hg").unwrap(),
+        Pattern::new(".mypy_cache").unwrap(),
+        Pattern::new(".nox").unwrap(),
+        Pattern::new(".pants.d").unwrap(),
+        Pattern::new(".ruff_cache").unwrap(),
+        Pattern::new(".svn").unwrap(),
+        Pattern::new(".tox").unwrap(),
+        Pattern::new(".venv").unwrap(),
+        Pattern::new("__pypackages__").unwrap(),
+        Pattern::new("_build").unwrap(),
+        Pattern::new("buck-out").unwrap(),
+        Pattern::new("build").unwrap(),
+        Pattern::new("dist").unwrap(),
+        Pattern::new("node_modules").unwrap(),
+        Pattern::new("venv").unwrap(),
+    ]
+});
+
 impl Settings {
-    pub fn from_paths<'a>(paths: impl IntoIterator<Item = &'a Path>) -> Result<Self> {
-        let (project_root, config) = load_config(paths)?;
-        Ok(Settings {
+    pub fn from_paths(paths: &[PathBuf]) -> Self {
+        let config = load_config(paths);
+        let mut settings = Settings {
            line_length: config.line_length.unwrap_or(88),
            exclude: config
                .exclude
-                .unwrap_or_default()
-                .into_iter()
-                .map(|path| {
-                    if path.is_relative() {
-                        project_root.join(path)
-                    } else {
-                        path
-                    }
+                .map(|paths| {
+                    paths
+                        .iter()
+                        .map(|path| {
+                            Pattern::new(&path.to_string_lossy()).expect("Invalid pattern.")
+                        })
+                        .collect()
                })
-                .map(|path| Pattern::new(&path.to_string_lossy()).expect("Invalid pattern."))
-                .collect(),
-            select: config.select.unwrap_or_else(|| {
-                BTreeSet::from([
+                .unwrap_or_else(|| DEFAULT_EXCLUDE.clone()),
+            extend_exclude: config
+                .extend_exclude
+                .map(|paths| {
+                    paths
+                        .iter()
+                        .map(|path| {
+                            Pattern::new(&path.to_string_lossy()).expect("Invalid pattern.")
+                        })
+                        .collect()
+                })
+                .unwrap_or_default(),
+            select: BTreeSet::from_iter(config.select.unwrap_or_else(|| {
+                vec![
                    CheckCode::E402,
                    CheckCode::E501,
                    CheckCode::E711,
                    CheckCode::E712,
                    CheckCode::E713,
                    CheckCode::E714,
+                    CheckCode::E721,
+                    CheckCode::E722,
                    CheckCode::E731,
+                    CheckCode::E741,
+                    CheckCode::E742,
+                    CheckCode::E743,
                    CheckCode::E902,
+                    CheckCode::E999,
                    CheckCode::F401,
                    CheckCode::F403,
+                    CheckCode::F406,
+                    CheckCode::F407,
                    CheckCode::F541,
+                    CheckCode::F601,
+                    CheckCode::F602,
+                    CheckCode::F621,
+                    CheckCode::F622,
                    CheckCode::F631,
+                    CheckCode::F632,
+                    CheckCode::F633,
                    CheckCode::F634,
+                    CheckCode::F701,
+                    CheckCode::F702,
                    CheckCode::F704,
                    CheckCode::F706,
                    CheckCode::F707,
+                    CheckCode::F722,
                    CheckCode::F821,
                    CheckCode::F822,
                    CheckCode::F823,
@@ -69,9 +120,13 @@ impl Settings {
                    // Disable refactoring codes by default.
                    // CheckCode::R001,
                    // CheckCode::R002,
-                ])
-            }),
-        })
+                ]
+            })),
+        };
+        if let Some(ignore) = &config.ignore {
+            settings.ignore(ignore);
+        }
+        settings
    }

    pub fn select(&mut self, codes: Vec<CheckCode>) {
--- a/src/snapshots/rufflintertests__e402.snap
+++ b/src/snapshots/rufflintertests__e402.snap
@@ -0,0 +1,10 @@
+---
+source: src/linter.rs
+expression: checks
+---
+- kind: ModuleImportNotAtTopOfFile
+  location:
+    row: 20
+    column: 1
+  fix: ~
+
--- a/src/snapshots/rufflintertests__e501.snap
+++ b/src/snapshots/rufflintertests__e501.snap
@@ -0,0 +1,13 @@
+---
+source: src/linter.rs
+expression: checks
+---
+- kind:
+    LineTooLong:
+      - 123
+      - 88
+  location:
+    row: 5
+    column: 89
+  fix: ~
+
--- a/src/snapshots/rufflintertests__e711.snap
+++ b/src/snapshots/rufflintertests__e711.snap
@@ -0,0 +1,53 @@
+---
+source: src/linter.rs
+expression: checks
+---
+- kind:
+    NoneComparison: Eq
+  location:
+    row: 2
+    column: 11
+  fix: ~
+- kind:
+    NoneComparison: NotEq
+  location:
+    row: 5
+    column: 11
+  fix: ~
+- kind:
+    NoneComparison: Eq
+  location:
+    row: 8
+    column: 4
+  fix: ~
+- kind:
+    NoneComparison: NotEq
+  location:
+    row: 11
+    column: 4
+  fix: ~
+- kind:
+    NoneComparison: Eq
+  location:
+    row: 14
+    column: 14
+  fix: ~
+- kind:
+    NoneComparison: NotEq
+  location:
+    row: 17
+    column: 14
+  fix: ~
+- kind:
+    NoneComparison: NotEq
+  location:
+    row: 20
+    column: 4
+  fix: ~
+- kind:
+    NoneComparison: Eq
+  location:
+    row: 23
+    column: 4
+  fix: ~
+
--- a/src/snapshots/rufflintertests__e712.snap
+++ b/src/snapshots/rufflintertests__e712.snap
@@ -0,0 +1,77 @@
+---
+source: src/linter.rs
+expression: checks
+---
+- kind:
+    TrueFalseComparison:
+      - true
+      - Eq
+  location:
+    row: 2
+    column: 11
+  fix: ~
+- kind:
+    TrueFalseComparison:
+      - false
+      - NotEq
+  location:
+    row: 5
+    column: 11
+  fix: ~
+- kind:
+    TrueFalseComparison:
+      - true
+      - NotEq
+  location:
+    row: 8
+    column: 4
+  fix: ~
+- kind:
+    TrueFalseComparison:
+      - false
+      - Eq
+  location:
+    row: 11
+    column: 4
+  fix: ~
+- kind:
+    TrueFalseComparison:
+      - true
+      - Eq
+  location:
+    row: 14
+    column: 14
+  fix: ~
+- kind:
+    TrueFalseComparison:
+      - false
+      - NotEq
+  location:
+    row: 17
+    column: 14
+  fix: ~
+- kind:
+    TrueFalseComparison:
+      - true
+      - Eq
+  location:
+    row: 20
+    column: 20
+  fix: ~
+- kind:
+    TrueFalseComparison:
+      - false
+      - Eq
+  location:
+    row: 20
+    column: 44
+  fix: ~
+- kind:
+    TrueFalseComparison:
+      - true
+      - Eq
+  location:
+    row: 22
+    column: 5
+  fix: ~
+
--- a/src/snapshots/rufflintertests__e713.snap
+++ b/src/snapshots/rufflintertests__e713.snap
@@ -0,0 +1,30 @@
+---
+source: src/linter.rs
+expression: checks
+---
+- kind: NotInTest
+  location:
+    row: 2
+    column: 10
+  fix: ~
+- kind: NotInTest
+  location:
+    row: 5
+    column: 12
+  fix: ~
+- kind: NotInTest
+  location:
+    row: 8
+    column: 10
+  fix: ~
+- kind: NotInTest
+  location:
+    row: 11
+    column: 25
+  fix: ~
+- kind: NotInTest
+  location:
+    row: 14
+    column: 11
+  fix: ~
+
--- a/src/snapshots/rufflintertests__e714.snap
+++ b/src/snapshots/rufflintertests__e714.snap
@@ -0,0 +1,20 @@
+---
+source: src/linter.rs
+expression: checks
+---
+- kind: NotIsTest
+  location:
+    row: 2
+    column: 10
+  fix: ~
+- kind: NotIsTest
+  location:
+    row: 5
+    column: 12
+  fix: ~
+- kind: NotIsTest
+  location:
+    row: 8
+    column: 10
+  fix: ~
+
--- a/src/snapshots/rufflintertests__e721.snap
+++ b/src/snapshots/rufflintertests__e721.snap
@@ -0,0 +1,85 @@
+---
+source: src/linter.rs
+expression: checks
+---
+- kind: TypeComparison
+  location:
+    row: 2
+    column: 14
+  fix: ~
+- kind: TypeComparison
+  location:
+    row: 5
+    column: 14
+  fix: ~
+- kind: TypeComparison
+  location:
+    row: 10
+    column: 8
+  fix: ~
+- kind: TypeComparison
+  location:
+    row: 15
+    column: 14
+  fix: ~
+- kind: TypeComparison
+  location:
+    row: 18
+    column: 18
+  fix: ~
+- kind: TypeComparison
+  location:
+    row: 18
+    column: 46
+  fix: ~
+- kind: TypeComparison
+  location:
+    row: 20
+    column: 18
+  fix: ~
+- kind: TypeComparison
+  location:
+    row: 22
+    column: 18
+  fix: ~
+- kind: TypeComparison
+  location:
+    row: 24
+    column: 18
+  fix: ~
+- kind: TypeComparison
+  location:
+    row: 26
+    column: 18
+  fix: ~
+- kind: TypeComparison
+  location:
+    row: 28
+    column: 18
+  fix: ~
+- kind: TypeComparison
+  location:
+    row: 30
+    column: 18
+  fix: ~
+- kind: TypeComparison
+  location:
+    row: 32
+    column: 18
+  fix: ~
+- kind: TypeComparison
+  location:
+    row: 34
+    column: 18
+  fix: ~
+- kind: TypeComparison
+  location:
+    row: 40
+    column: 18
+  fix: ~
+- kind: TypeComparison
+  location:
+    row: 42
+    column: 18
+  fix: ~
+
--- a/src/snapshots/rufflintertests__e722.snap
+++ b/src/snapshots/rufflintertests__e722.snap
@@ -0,0 +1,20 @@
+---
+source: src/linter.rs
+expression: checks
+---
+- kind: DoNotUseBareExcept
+  location:
+    row: 4
+    column: 1
+  fix: ~
+- kind: DoNotUseBareExcept
+  location:
+    row: 11
+    column: 1
+  fix: ~
+- kind: DoNotUseBareExcept
+  location:
+    row: 16
+    column: 1
+  fix: ~
+
--- a/src/snapshots/rufflintertests__e731.snap
+++ b/src/snapshots/rufflintertests__e731.snap
@@ -0,0 +1,30 @@
+---
+source: src/linter.rs
+expression: checks
+---
+- kind: DoNotAssignLambda
+  location:
+    row: 2
+    column: 1
+  fix: ~
+- kind: DoNotAssignLambda
+  location:
+    row: 4
+    column: 1
+  fix: ~
+- kind: DoNotAssignLambda
+  location:
+    row: 7
+    column: 5
+  fix: ~
+- kind: DoNotAssignLambda
+  location:
+    row: 12
+    column: 1
+  fix: ~
+- kind: DoNotAssignLambda
+  location:
+    row: 16
+    column: 1
+  fix: ~
+
--- a/src/snapshots/rufflintertests__e741.snap
+++ b/src/snapshots/rufflintertests__e741.snap
@@ -0,0 +1,155 @@
+---
+source: src/linter.rs
+expression: checks
+---
+- kind:
+    AmbiguousVariableName: l
+  location:
+    row: 3
+    column: 1
+  fix: ~
+- kind:
+    AmbiguousVariableName: I
+  location:
+    row: 4
+    column: 1
+  fix: ~
+- kind:
+    AmbiguousVariableName: O
+  location:
+    row: 5
+    column: 1
+  fix: ~
+- kind:
+    AmbiguousVariableName: l
+  location:
+    row: 6
+    column: 1
+  fix: ~
+- kind:
+    AmbiguousVariableName: l
+  location:
+    row: 8
+    column: 4
+  fix: ~
+- kind:
+    AmbiguousVariableName: l
+  location:
+    row: 9
+    column: 5
+  fix: ~
+- kind:
+    AmbiguousVariableName: l
+  location:
+    row: 10
+    column: 5
+  fix: ~
+- kind:
+    AmbiguousVariableName: l
+  location:
+    row: 11
+    column: 5
+  fix: ~
+- kind:
+    AmbiguousVariableName: l
+  location:
+    row: 16
+    column: 5
+  fix: ~
+- kind:
+    AmbiguousVariableName: l
+  location:
+    row: 20
+    column: 8
+  fix: ~
+- kind:
+    AmbiguousVariableName: l
+  location:
+    row: 25
+    column: 5
+  fix: ~
+- kind:
+    AmbiguousVariableName: l
+  location:
+    row: 26
+    column: 5
+  fix: ~
+- kind:
+    AmbiguousVariableName: l
+  location:
+    row: 30
+    column: 5
+  fix: ~
+- kind:
+    AmbiguousVariableName: l
+  location:
+    row: 33
+    column: 9
+  fix: ~
+- kind:
+    AmbiguousVariableName: l
+  location:
+    row: 34
+    column: 9
+  fix: ~
+- kind:
+    AmbiguousVariableName: l
+  location:
+    row: 40
+    column: 8
+  fix: ~
+- kind:
+    AmbiguousVariableName: I
+  location:
+    row: 40
+    column: 14
+  fix: ~
+- kind:
+    AmbiguousVariableName: l
+  location:
+    row: 44
+    column: 8
+  fix: ~
+- kind:
+    AmbiguousVariableName: I
+  location:
+    row: 44
+    column: 16
+  fix: ~
+- kind:
+    AmbiguousVariableName: l
+  location:
+    row: 48
+    column: 9
+  fix: ~
+- kind:
+    AmbiguousVariableName: I
+  location:
+    row: 48
+    column: 14
+  fix: ~
+- kind:
+    AmbiguousVariableName: l
+  location:
+    row: 57
+    column: 16
+  fix: ~
+- kind:
+    AmbiguousVariableName: l
+  location:
+    row: 66
+    column: 20
+  fix: ~
+- kind:
+    AmbiguousVariableName: l
+  location:
+    row: 71
+    column: 1
+  fix: ~
+- kind:
+    AmbiguousVariableName: l
+  location:
+    row: 74
+    column: 5
+  fix: ~
+
--- a/src/snapshots/rufflintertests__e742.snap
+++ b/src/snapshots/rufflintertests__e742.snap
@@ -0,0 +1,23 @@
+---
+source: src/linter.rs
+expression: checks
+---
+- kind:
+    AmbiguousClassName: l
+  location:
+    row: 1
+    column: 1
+  fix: ~
+- kind:
+    AmbiguousClassName: I
+  location:
+    row: 5
+    column: 1
+  fix: ~
+- kind:
+    AmbiguousClassName: O
+  location:
+    row: 9
+    column: 1
+  fix: ~
+
--- a/src/snapshots/rufflintertests__e743.snap
+++ b/src/snapshots/rufflintertests__e743.snap
@@ -0,0 +1,23 @@
+---
+source: src/linter.rs
+expression: checks
+---
+- kind:
+    AmbiguousFunctionName: l
+  location:
+    row: 1
+    column: 1
+  fix: ~
+- kind:
+    AmbiguousFunctionName: I
+  location:
+    row: 5
+    column: 1
+  fix: ~
+- kind:
+    AmbiguousFunctionName: O
+  location:
+    row: 10
+    column: 5
+  fix: ~
+
--- a/src/snapshots/rufflintertests__f401.snap
+++ b/src/snapshots/rufflintertests__f401.snap
@@ -0,0 +1,23 @@
+---
+source: src/linter.rs
+expression: checks
+---
+- kind:
+    UnusedImport: functools
+  location:
+    row: 3
+    column: 1
+  fix: ~
+- kind:
+    UnusedImport: collections.OrderedDict
+  location:
+    row: 5
+    column: 1
+  fix: ~
+- kind:
+    UnusedImport: logging.handlers
+  location:
+    row: 13
+    column: 1
+  fix: ~
+
--- a/src/snapshots/rufflintertests__f403.snap
+++ b/src/snapshots/rufflintertests__f403.snap
@@ -0,0 +1,17 @@
+---
+source: src/linter.rs
+expression: checks
+---
+- kind:
+    ImportStarUsage: F634
+  location:
+    row: 1
+    column: 1
+  fix: ~
+- kind:
+    ImportStarUsage: F634
+  location:
+    row: 2
+    column: 1
+  fix: ~
+
--- a/src/snapshots/rufflintertests__f404.snap
+++ b/src/snapshots/rufflintertests__f404.snap
@@ -0,0 +1,10 @@
+---
+source: src/linter.rs
+expression: checks
+---
+- kind: LateFutureImport
+  location:
+    row: 7
+    column: 1
+  fix: ~
+
--- a/src/snapshots/rufflintertests__f406.snap
+++ b/src/snapshots/rufflintertests__f406.snap
@@ -0,0 +1,17 @@
+---
+source: src/linter.rs
+expression: checks
+---
+- kind:
+    ImportStarNotPermitted: F634
+  location:
+    row: 5
+    column: 5
+  fix: ~
+- kind:
+    ImportStarNotPermitted: F634
+  location:
+    row: 9
+    column: 5
+  fix: ~
+
--- a/src/snapshots/rufflintertests__f407.snap
+++ b/src/snapshots/rufflintertests__f407.snap
@@ -0,0 +1,11 @@
+---
+source: src/linter.rs
+expression: checks
+---
+- kind:
+    FutureFeatureNotDefined: non_existent_feature
+  location:
+    row: 2
+    column: 1
+  fix: ~
+
--- a/src/snapshots/rufflintertests__f541.snap
+++ b/src/snapshots/rufflintertests__f541.snap
@@ -0,0 +1,20 @@
+---
+source: src/linter.rs
+expression: checks
+---
+- kind: FStringMissingPlaceholders
+  location:
+    row: 4
+    column: 7
+  fix: ~
+- kind: FStringMissingPlaceholders
+  location:
+    row: 5
+    column: 7
+  fix: ~
+- kind: FStringMissingPlaceholders
+  location:
+    row: 7
+    column: 7
+  fix: ~
+
--- a/src/snapshots/rufflintertests__f601.snap
+++ b/src/snapshots/rufflintertests__f601.snap
@@ -0,0 +1,20 @@
+---
+source: src/linter.rs
+expression: checks
+---
+- kind: MultiValueRepeatedKeyLiteral
+  location:
+    row: 3
+    column: 6
+  fix: ~
+- kind: MultiValueRepeatedKeyLiteral
+  location:
+    row: 9
+    column: 5
+  fix: ~
+- kind: MultiValueRepeatedKeyLiteral
+  location:
+    row: 11
+    column: 7
+  fix: ~
+
--- a/src/snapshots/rufflintertests__f602.snap
+++ b/src/snapshots/rufflintertests__f602.snap
@@ -0,0 +1,11 @@
+---
+source: src/linter.rs
+expression: checks
+---
+- kind:
+    MultiValueRepeatedKeyVariable: a
+  location:
+    row: 5
+    column: 5
+  fix: ~
+
--- a/src/snapshots/rufflintertests__f622.snap
+++ b/src/snapshots/rufflintertests__f622.snap
@@ -0,0 +1,10 @@
+---
+source: src/linter.rs
+expression: checks
+---
+- kind: TwoStarredExpressions
+  location:
+    row: 1
+    column: 1
+  fix: ~
+
--- a/src/snapshots/rufflintertests__f631.snap
+++ b/src/snapshots/rufflintertests__f631.snap
@@ -0,0 +1,15 @@
+---
+source: src/linter.rs
+expression: checks
+---
+- kind: AssertTuple
+  location:
+    row: 1
+    column: 1
+  fix: ~
+- kind: AssertTuple
+  location:
+    row: 2
+    column: 1
+  fix: ~
+
--- a/src/snapshots/rufflintertests__f632.snap
+++ b/src/snapshots/rufflintertests__f632.snap
@@ -0,0 +1,15 @@
+---
+source: src/linter.rs
+expression: checks
+---
+- kind: IsLiteral
+  location:
+    row: 1
+    column: 6
+  fix: ~
+- kind: IsLiteral
+  location:
+    row: 4
+    column: 8
+  fix: ~
+
--- a/src/snapshots/rufflintertests__f633.snap
+++ b/src/snapshots/rufflintertests__f633.snap
@@ -0,0 +1,10 @@
+---
+source: src/linter.rs
+expression: checks
+---
+- kind: InvalidPrintSyntax
+  location:
+    row: 4
+    column: 1
+  fix: ~
+
--- a/src/snapshots/rufflintertests__f634.snap
+++ b/src/snapshots/rufflintertests__f634.snap
@@ -0,0 +1,15 @@
+---
+source: src/linter.rs
+expression: checks
+---
+- kind: IfTuple
+  location:
+    row: 1
+    column: 1
+  fix: ~
+- kind: IfTuple
+  location:
+    row: 7
+    column: 5
+  fix: ~
+
--- a/src/snapshots/rufflintertests__f701.snap
+++ b/src/snapshots/rufflintertests__f701.snap
@@ -0,0 +1,25 @@
+---
+source: src/linter.rs
+expression: checks
+---
+- kind: BreakOutsideLoop
+  location:
+    row: 4
+    column: 5
+  fix: ~
+- kind: BreakOutsideLoop
+  location:
+    row: 16
+    column: 5
+  fix: ~
+- kind: BreakOutsideLoop
+  location:
+    row: 20
+    column: 5
+  fix: ~
+- kind: BreakOutsideLoop
+  location:
+    row: 23
+    column: 1
+  fix: ~
+
--- a/src/snapshots/rufflintertests__f702.snap
+++ b/src/snapshots/rufflintertests__f702.snap
@@ -0,0 +1,25 @@
+---
+source: src/linter.rs
+expression: checks
+---
+- kind: ContinueOutsideLoop
+  location:
+    row: 4
+    column: 5
+  fix: ~
+- kind: ContinueOutsideLoop
+  location:
+    row: 16
+    column: 5
+  fix: ~
+- kind: ContinueOutsideLoop
+  location:
+    row: 20
+    column: 5
+  fix: ~
+- kind: ContinueOutsideLoop
+  location:
+    row: 23
+    column: 1
+  fix: ~
+
--- a/src/snapshots/rufflintertests__f704.snap
+++ b/src/snapshots/rufflintertests__f704.snap
@@ -0,0 +1,20 @@
+---
+source: src/linter.rs
+expression: checks
+---
+- kind: YieldOutsideFunction
+  location:
+    row: 6
+    column: 5
+  fix: ~
+- kind: YieldOutsideFunction
+  location:
+    row: 9
+    column: 1
+  fix: ~
+- kind: YieldOutsideFunction
+  location:
+    row: 10
+    column: 1
+  fix: ~
+
--- a/src/snapshots/rufflintertests__f706.snap
+++ b/src/snapshots/rufflintertests__f706.snap
@@ -0,0 +1,15 @@
+---
+source: src/linter.rs
+expression: checks
+---
+- kind: ReturnOutsideFunction
+  location:
+    row: 6
+    column: 5
+  fix: ~
+- kind: ReturnOutsideFunction
+  location:
+    row: 9
+    column: 1
+  fix: ~
+
--- a/src/snapshots/rufflintertests__f707.snap
+++ b/src/snapshots/rufflintertests__f707.snap
@@ -0,0 +1,20 @@
+---
+source: src/linter.rs
+expression: checks
+---
+- kind: DefaultExceptNotLast
+  location:
+    row: 3
+    column: 1
+  fix: ~
+- kind: DefaultExceptNotLast
+  location:
+    row: 10
+    column: 1
+  fix: ~
+- kind: DefaultExceptNotLast
+  location:
+    row: 19
+    column: 1
+  fix: ~
+
--- a/src/snapshots/rufflintertests__f722.snap
+++ b/src/snapshots/rufflintertests__f722.snap
@@ -0,0 +1,11 @@
+---
+source: src/linter.rs
+expression: checks
+---
+- kind:
+    ForwardAnnotationSyntaxError: ///
+  location:
+    row: 9
+    column: 13
+  fix: ~
+
--- a/src/snapshots/rufflintertests__f821.snap
+++ b/src/snapshots/rufflintertests__f821.snap
@@ -0,0 +1,41 @@
+---
+source: src/linter.rs
+expression: checks
+---
+- kind:
+    UndefinedName: self
+  location:
+    row: 2
+    column: 12
+  fix: ~
+- kind:
+    UndefinedName: self
+  location:
+    row: 6
+    column: 13
+  fix: ~
+- kind:
+    UndefinedName: self
+  location:
+    row: 10
+    column: 9
+  fix: ~
+- kind:
+    UndefinedName: numeric_string
+  location:
+    row: 21
+    column: 12
+  fix: ~
+- kind:
+    UndefinedName: Bar
+  location:
+    row: 58
+    column: 5
+  fix: ~
+- kind:
+    UndefinedName: TOMATO
+  location:
+    row: 83
+    column: 11
+  fix: ~
+
--- a/src/snapshots/rufflintertests__f822.snap
+++ b/src/snapshots/rufflintertests__f822.snap
@@ -0,0 +1,11 @@
+---
+source: src/linter.rs
+expression: checks
+---
+- kind:
+    UndefinedExport: b
+  location:
+    row: 3
+    column: 1
+  fix: ~
+
--- a/src/snapshots/rufflintertests__f823.snap
+++ b/src/snapshots/rufflintertests__f823.snap
@@ -0,0 +1,11 @@
+---
+source: src/linter.rs
+expression: checks
+---
+- kind:
+    UndefinedLocal: my_var
+  location:
+    row: 6
+    column: 5
+  fix: ~
+
--- a/src/snapshots/rufflintertests__f831.snap
+++ b/src/snapshots/rufflintertests__f831.snap
@@ -0,0 +1,20 @@
+---
+source: src/linter.rs
+expression: checks
+---
+- kind: DuplicateArgumentName
+  location:
+    row: 1
+    column: 25
+  fix: ~
+- kind: DuplicateArgumentName
+  location:
+    row: 5
+    column: 28
+  fix: ~
+- kind: DuplicateArgumentName
+  location:
+    row: 9
+    column: 27
+  fix: ~
+
--- a/src/snapshots/rufflintertests__f841.snap
+++ b/src/snapshots/rufflintertests__f841.snap
@@ -0,0 +1,35 @@
+---
+source: src/linter.rs
+expression: checks
+---
+- kind:
+    UnusedVariable: e
+  location:
+    row: 3
+    column: 1
+  fix: ~
+- kind:
+    UnusedVariable: z
+  location:
+    row: 16
+    column: 5
+  fix: ~
+- kind:
+    UnusedVariable: foo
+  location:
+    row: 20
+    column: 5
+  fix: ~
+- kind:
+    UnusedVariable: a
+  location:
+    row: 21
+    column: 6
+  fix: ~
+- kind:
+    UnusedVariable: b
+  location:
+    row: 21
+    column: 9
+  fix: ~
+
--- a/src/snapshots/rufflintertests__f901.snap
+++ b/src/snapshots/rufflintertests__f901.snap
@@ -0,0 +1,15 @@
+---
+source: src/linter.rs
+expression: checks
+---
+- kind: RaiseNotImplemented
+  location:
+    row: 2
+    column: 25
+  fix: ~
+- kind: RaiseNotImplemented
+  location:
+    row: 6
+    column: 11
+  fix: ~
+
--- a/src/snapshots/rufflintertests__future_annotations.snap
+++ b/src/snapshots/rufflintertests__future_annotations.snap
@@ -0,0 +1,17 @@
+---
+source: src/linter.rs
+expression: checks
+---
+- kind:
+    UnusedImport: models.Nut
+  location:
+    row: 5
+    column: 1
+  fix: ~
+- kind:
+    UndefinedName: Bar
+  location:
+    row: 22
+    column: 19
+  fix: ~
+
--- a/src/snapshots/rufflintertests__init.snap
+++ b/src/snapshots/rufflintertests__init.snap
@@ -0,0 +1,6 @@
+---
+source: src/linter.rs
+expression: checks
+---
+[]
+
--- a/Show More
+++ b/Show More
Author	SHA1	Message	Date
Charlie Marsh	06e5b3e457	Bump version to 0.0.39	2022-09-15 21:41:14 -04:00
Charlie Marsh	68a0e6dc19	Remove erroneous test dir	2022-09-15 21:41:00 -04:00
Charlie Marsh	9d4a4478f7	Improve exclusion syntax to match exact files (#209 )	2022-09-15 21:40:49 -04:00
Charlie Marsh	6bbf3f46c4	Add .gitignore to .ruff_cache (#208 )	2022-09-15 20:40:06 -04:00
Charlie Marsh	4ac4e8c991	Exclude .ruff_cache by default (#207 )	2022-09-15 20:39:39 -04:00
Dmitry Dygalo	0091a3ae5f	chore: Do not read the same file twice (#206 )	2022-09-15 16:05:29 -04:00
Patrick Haller	17b3109a8b	Update docs with --format flag (#205 )	2022-09-15 16:04:07 -04:00
Charlie Marsh	71520213c1	Allow __path__ in __init__.py (#201 )	2022-09-15 09:44:03 -04:00
Charlie Marsh	f24e7a0052	Add trailing period to help message	2022-09-15 09:43:51 -04:00
Patrick Haller	507e9f7ec3	Fix: Structured output Issue Fix (#186 )	2022-09-15 09:43:10 -04:00
Charlie Marsh	592c53c8bf	Use binding location when reporting F821 errors (#200 )	2022-09-14 22:51:07 -04:00
Charlie Marsh	a2df89dedd	Bump version to 0.0.38	2022-09-14 22:38:42 -04:00
Charlie Marsh	b8f12d2e79	Raise error when failing to parse (#199 )	2022-09-14 22:37:55 -04:00
Charlie Marsh	67b1d0463a	Pull in pycodestyle tests for E checks (#195 )	2022-09-14 22:22:53 -04:00
Charlie Marsh	d008a181ec	Improve default exclusions and support extend-exclude (#188 )	2022-09-14 22:21:17 -04:00
Charlie Marsh	6d612a428a	Migrate linter tests to insta (#194 )	2022-09-14 21:52:44 -04:00
Charlie Marsh	c0cb73ab16	Implement E721 (#193 )	2022-09-14 21:10:29 -04:00
Charlie Marsh	2e1eb84cbf	Implement F632 (#190 )	2022-09-14 18:22:35 -04:00
Charlie Marsh	b03a8728b5	Add support for from __future__ import annotations (#189 )	2022-09-14 18:22:19 -04:00
Charlie Marsh	1dd3350a30	Revert "Adding flag and logic for different output format" (#187 )	2022-09-14 14:20:02 -04:00
Patrick Haller	bda34945a5	Adding flag and logic for different output format (#185 )	2022-09-14 10:43:32 -04:00
Dmitry Dygalo	85dcaa8d3c	chore: Avoid `collect` in `inner_main` (#184 )	2022-09-14 08:16:04 -04:00
Charlie Marsh	4ac74ed0ad	Revert erroneous pyproject.toml changes	2022-09-14 08:14:26 -04:00
Dmitry Dygalo	b7e2a4b9a9	feat: Implement `InvalidPrintSyntax` (`F633`) (#182 )	2022-09-13 21:10:20 -04:00
Dmitry Dygalo	53a7758248	Avoid some allocations (#179 )	2022-09-13 10:07:22 -04:00
Dmitry Dygalo	2ba767957d	refactor: Use `while let Some` instead of calling `is_empty` (#180 )	2022-09-13 10:06:49 -04:00
Dmitry Dygalo	08152787e1	chore: Use `once_cell` instead of `lazy_static` (#178 )	2022-09-13 10:06:21 -04:00
Charlie Marsh	5f77b420cd	Bump version to 0.0.37	2022-09-12 21:35:08 -04:00
Charlie Marsh	90f9e60517	Implement F722 (#175 )	2022-09-12 21:34:27 -04:00
Brian Okken	320737f6e4	Change URL to comply with PEP 621 (#173 )	2022-09-12 18:38:20 -04:00
Charlie Marsh	dfba1416b2	Implement F406 (#172 )	2022-09-12 16:47:30 -04:00
Charlie Marsh	2ca3f35bd1	Remove one match from checks.rs	2022-09-12 16:32:27 -04:00
Adrian Garcia Badaracco	b1c40d5fa7	Run MacOS builds in parallel (#171 )	2022-09-12 16:24:13 -04:00
Charlie Marsh	a129e27b3e	Tweak rule counts	2022-09-12 15:26:21 -04:00
Charlie Marsh	ad7daa008e	Update README to enumerate missing Flake8 rules	2022-09-12 15:24:32 -04:00
Charlie Marsh	062d7081a0	Bump version to 0.0.36	2022-09-12 11:16:26 -04:00
Charlie Marsh	40c1e7e005	Implement F701 and F702 (#169 )	2022-09-12 11:16:08 -04:00
Charlie Marsh	3cbd05ddff	Update README	2022-09-12 09:31:16 -04:00
Harutaka Kawamura	9414090617	Implement E722 (#166 )	2022-09-12 09:04:39 -04:00
Harutaka Kawamura	825777edc1	Add test case for assignment expression in `E741.py` (#168 )	2022-09-12 09:03:36 -04:00
Charlie Marsh	4e0807e908	Include line length in E501 messages (#165 )	2022-09-11 22:54:11 -04:00
Charlie Marsh	546be5692a	Bump version to 0.0.35	2022-09-11 21:54:00 -04:00
Charlie Marsh	43e1f20b28	Allow unused assignments in for loops and unpacking (#163 )	2022-09-11 21:53:45 -04:00
Harutaka Kawamura	97388cefda	Implement E743 (#162 )	2022-09-11 21:27:33 -04:00
Harutaka Kawamura	63ce579989	Implement E742 (#160 )	2022-09-11 20:27:48 -04:00
Charlie Marsh	5f4a62aa40	Bump version to 0.0.34	2022-09-11 18:05:52 -04:00
Charlie Marsh	02ab52b3e2	Implement F407 (#158 )	2022-09-11 18:05:28 -04:00
Charlie Marsh	549732b1da	Implement F404 (#159 )	2022-09-11 18:05:00 -04:00
Harutaka Kawamura	c4565fe0f5	Implement E741 (#137 )	2022-09-11 12:30:28 -04:00
Charlie Marsh	81ae3bfc94	Bump version to 0.0.33	2022-09-11 10:45:02 -04:00
Charlie Marsh	62e6feadc7	Handle accesses within inner functions (#156 )	2022-09-11 10:44:27 -04:00
Charlie Marsh	18a26e8f0b	Allow setting --exclude on the command-line (#157 )	2022-09-11 10:44:23 -04:00
Charlie Marsh	2371de3895	Make late imports more permissive (#155 )	2022-09-11 10:44:06 -04:00
Charlie Marsh	e3c8f61340	Ignore deletes in conditional branches (#154 )	2022-09-11 10:28:07 -04:00
Harutaka Kawamura	f6628ae100	Fix `Message.cmp` (#152 )	2022-09-11 10:18:27 -04:00
Jakub Kuczys	989ed9c10b	Fix ruff's pyproject.toml section name in README.md (#148 )	2022-09-11 10:18:19 -04:00
Charlie Marsh	8698c06c36	Bump version to 0.0.32	2022-09-10 15:21:01 -04:00
Charlie Marsh	dfd8a4158d	Parse function annotations within the ClassDef scope (#144 )	2022-09-10 15:20:39 -04:00
Charlie Marsh	c247730bf5	Avoid treating keys as annotations in TypedDict	2022-09-10 15:19:11 -04:00
Charlie Marsh	024472d578	Implement F621 and F622 (#143 )	2022-09-10 15:04:33 -04:00
Charlie Marsh	7d69a153e8	Support remaining typing module members (#141 )	2022-09-10 14:51:43 -04:00
Charlie Marsh	4fc68e0310	Bump version to 0.0.31	2022-09-10 13:05:15 -04:00
Charlie Marsh	6a24351202	Add support for TypedDict	2022-09-10 13:03:29 -04:00
Charlie Marsh	d7f95ac6b6	Upgrade RustPython parser to handle list assignments	2022-09-10 12:53:07 -04:00
Charlie Marsh	11234ea555	Add await to YieldOutsideFunction	2022-09-08 22:54:11 -04:00
Charlie Marsh	b536159541	Pull check logic out of check_ast.rs (#135 )	2022-09-08 22:46:42 -04:00
Charlie Marsh	7c17785eac	Bump version to 0.0.30	2022-09-08 11:42:45 -04:00
Charlie Marsh	f1acd28f08	Skip slice error for invalid TypeVar calls	2022-09-08 11:40:55 -04:00
Charlie Marsh	c61ff9a947	Adjust location when parsing deferred type annotations (#133 )	2022-09-08 11:37:19 -04:00
Charlie Marsh	2c64cf3149	Add support for Literal, Type, and TypeVar (#131 )	2022-09-08 11:07:45 -04:00
Charlie Marsh	fc5f34c76f	Use scope-tracking logic for parents (#130 )	2022-09-08 09:14:58 -04:00
Charlie Marsh	a8f4faa6e4	Fix crash on missing parent	2022-09-07 22:40:25 -04:00
Charlie Marsh	2ac5c830c1	Parse assignment annotations prior to targets (#127 )	2022-09-07 22:35:39 -04:00
Charlie Marsh	994f12050d	Support 'ignore' in pyproject.toml (#126 )	2022-09-07 22:34:51 -04:00
Charlie Marsh	fad4e4c51d	Defer checking of function bodies (#125 )	2022-09-07 22:34:43 -04:00
Charlie Marsh	c0042a3ca4	Use Mode::None for --no-cache	2022-09-07 21:47:07 -04:00
Charlie Marsh	5deb63a05f	Implement F601 and F602 (#122 )	2022-09-07 12:57:50 -04:00
Charlie Marsh	5e9ea8bda2	Add documentation on parity with Flake8	2022-09-07 10:32:28 -04:00