Bump version to 0.0.35

.pre-commit-config.yaml

@@ -1,5 +1,5 @@
 repos:
   - repo: https://github.com/charliermarsh/ruff
-    rev: v0.0.30
+    rev: v0.0.35
     hooks:
       - id: lint

Cargo.lock

@@ -1744,7 +1744,7 @@ dependencies = [
 
 [[package]]
 name = "ruff"
-version = "0.0.30"
+version = "0.0.35"
 dependencies = [
  "anyhow",
  "bincode",
@@ -1759,6 +1759,7 @@ dependencies = [
  "filetime",
  "glob",
  "itertools",
+ "lazy_static",
  "log",
  "notify",
  "once_cell",
@@ -1787,7 +1788,7 @@ 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 +1797,7 @@ 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 +1814,7 @@ 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",

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "ruff"
-version = "0.0.30"
+version = "0.0.35"
 edition = "2021"
 
 [lib]
@@ -20,12 +20,13 @@ fern = { version = "0.6.1" }
 filetime = { version = "0.2.17" }
 glob = { version = "0.3.0" }
 itertools = "0.10.3"
+lazy_static = "1.4.0"
 log = { version = "0.4.17" }
 notify = { version = "4.0.17" }
 once_cell = { version = "1.13.1" }
 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" }

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: v0.0.30
+  rev: v0.0.35
   hooks:
     - id: lint
 ```
@@ -86,7 +86,7 @@ ruff path/to/code/ --select F401 F403
 See `ruff --help` for more:
 
 ```shell
-ruff (v0.0.30)
+ruff (v0.0.35)
 An extremely fast Python linter.
 
 USAGE:
@@ -96,16 +96,17 @@ 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 file and/or directory patterns to exclude from checks
+    -f, --fix                     Attempt to automatically fix lint errors
+    -h, --help                    Print help information
+        --ignore <IGNORE>...      List of error codes to ignore
+    -n, --no-cache                Disable cache reads
+    -q, --quiet                   Disable all logging (but still exit with status code "1" upon
+                                  detecting errors)
+        --select <SELECT>...      List of error codes to enable
+    -v, --verbose                 Enable verbose logging
+    -w, --watch                   Run in watch mode by re-running whenever files change
 ```
 
 ### Compatibility with Black
@@ -123,7 +124,7 @@ ruff's goal is to achieve feature-parity with Flake8 when used (1) without any p
 stylistic checks; limiting to Python 3 obviates the need for certain compatibility checks.)
 
 Under those conditions, Flake8 implements about 58 rules, give or take. At time of writing, ruff
-implements 24 rules. (Note that these 24 rules likely cover a disproportionate share of errors:
+implements 33 rules. (Note that these 33 rules likely cover a disproportionate share of errors:
 unused imports, undefined variables, etc.)
 
 Of the unimplemented rules, ruff is missing:
@@ -152,12 +153,19 @@ Beyond rule-set parity, ruff suffers from the following limitations vis-à-vis F
 | E713 | NotInTest | Test for membership should be `not in` |
 | E714 | NotIsTest | Test for object identity should be `is not` |
 | E731 | DoNotAssignLambda | Do not assign a lambda expression, use a def |
+| E741 | AmbiguousVariableName | ambiguous variable name '...' |
+| E742 | AmbiguousClassName | ambiguous class name '...' |
+| E743 | AmbiguousFunctionName | ambiguous function name '...' |
 | E902 | IOError | No such file or directory: `...` |
 | F401 | UnusedImport | `...` imported but unused |
 | F403 | ImportStarUsage | Unable to detect undefined names |
+| F404 | LateFutureImport | from __future__ imports must occur at the beginning of the file |
+| 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` |
 | F634 | IfTuple | If test is a tuple, which is always `True` |
 | F704 | YieldOutsideFunction | a `yield` or `yield from` statement outside of a function/method |
@@ -204,7 +212,7 @@ 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",

examples/generate_rules_table.rs

@@ -3,14 +3,19 @@ use ruff::checks::{CheckKind, RejectedCmpop};
 
 fn main() {
     let mut check_kinds: Vec<CheckKind> = vec![
+        CheckKind::AmbiguousVariableName("...".to_string()),
+        CheckKind::AmbiguousClassName("...".to_string()),
+        CheckKind::AmbiguousFunctionName("...".to_string()),
         CheckKind::AssertTuple,
         CheckKind::DefaultExceptNotLast,
         CheckKind::DoNotAssignLambda,
         CheckKind::DuplicateArgumentName,
         CheckKind::FStringMissingPlaceholders,
+        CheckKind::FutureFeatureNotDefined("...".to_string()),
         CheckKind::IOError("...".to_string()),
         CheckKind::IfTuple,
         CheckKind::ImportStarUsage,
+        CheckKind::LateFutureImport,
         CheckKind::LineTooLong,
         CheckKind::ModuleImportNotAtTopOfFile,
         CheckKind::MultiValueRepeatedKeyLiteral,
@@ -21,7 +26,9 @@ fn main() {
         CheckKind::NotIsTest,
         CheckKind::RaiseNotImplemented,
         CheckKind::ReturnOutsideFunction,
+        CheckKind::TooManyExpressionsInStarredAssignment,
         CheckKind::TrueFalseComparison(true, RejectedCmpop::Eq),
+        CheckKind::TwoStarredExpressions,
         CheckKind::UndefinedExport("...".to_string()),
         CheckKind::UndefinedLocal("...".to_string()),
         CheckKind::UndefinedName("...".to_string()),

resources/test/fixtures/E741.py

@@ -0,0 +1,72 @@
+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

resources/test/fixtures/E742.py

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

resources/test/fixtures/E743.py

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

resources/test/fixtures/F401.py

@@ -11,10 +11,13 @@ import multiprocessing.pool
 import multiprocessing.process
 import logging.config
 import logging.handlers
-from typing import NamedTuple, Dict, Type, TypeVar, List, Set
+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
@@ -32,3 +35,7 @@ __all__ += ["ClassC"]
 X = TypeVar("X")
 Y = TypeVar("Y", bound="Dict")
 Z = TypeVar("Z", "List", "Set")
+
+a = list["Fruit"]
+b = Union["Nut", None]
+c = cast("Vegetable", b)

resources/test/fixtures/F404.py

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

resources/test/fixtures/F407.py

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

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)

resources/test/fixtures/F821.py

@@ -56,3 +56,24 @@ 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

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

resources/test/fixtures/pyproject.toml

@@ -9,12 +9,19 @@ select = [
     "E713",
     "E714",
     "E731",
+    "E741",
+    "E742",
+    "E743",
     "E902",
     "F401",
     "F403",
+    "F404",
+    "F407",
     "F541",
     "F601",
     "F602",
+    "F621",
+    "F622",
     "F631",
     "F634",
     "F704",

src/ast.rs

@@ -0,0 +1,5 @@
+pub mod checks;
+pub mod operations;
+pub mod relocate;
+pub mod types;
+pub mod visitor;

src/ast/checks.rs

@@ -0,0 +1,470 @@
+use std::collections::BTreeSet;
+
+use itertools::izip;
+use rustpython_parser::ast::{
+    Arg, Arguments, Cmpop, Constant, Excepthandler, ExcepthandlerKind, Expr, ExprKind, Keyword,
+    Location, Stmt, 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 {
+            match ops[..] {
+                [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)
+                            || matches!(autofix, 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)
+                        || matches!(autofix, 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
+}
+
+/// 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
+}

src/ast/operations.rs

@@ -1,58 +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)
-}
-
-#[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 {
-    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> {
@@ -118,6 +66,58 @@ pub fn extract_all_names(stmt: &Stmt, scope: &Scope) -> Vec<String> {
     names
 }
 
+/// Check if a node is parent of a conditional branch.
+pub fn on_conditional_branch(parent_stack: &[usize], parents: &[&Stmt]) -> bool {
+    for index in parent_stack.iter().rev() {
+        let parent = parents[*index];
+        if matches!(parent.node, StmtKind::If { .. })
+            || matches!(parent.node, 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 { .. })
+            || matches!(parent.node, StmtKind::If { .. })
+            || matches!(parent.node, 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,

src/ast/types.rs

@@ -0,0 +1,57 @@
+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,
+    pub used: Option<usize>,
+}

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;

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(())
+    }
+}

src/autofix/fixes.rs

@@ -2,7 +2,7 @@ use rustpython_parser::ast::{Expr, Keyword, Location};
 use rustpython_parser::lexer;
 use rustpython_parser::token::Tok;
 
-use crate::ast_ops::SourceCodeLocator;
+use crate::ast::operations::SourceCodeLocator;
 use crate::checks::Fix;
 
 /// Convert a location within a file (relative to `base`) to an absolute position.

src/cache.rs

@@ -8,7 +8,7 @@ use filetime::FileTime;
 use log::error;
 use serde::{Deserialize, Serialize};
 
-use crate::autofix;
+use crate::autofix::fixer;
 use crate::message::Message;
 use crate::settings::Settings;
 
@@ -71,7 +71,7 @@ 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);
@@ -87,7 +87,7 @@ 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 +116,7 @@ pub fn set(
     path: &Path,
     metadata: &Metadata,
     settings: &Settings,
-    autofix: &autofix::Mode,
+    autofix: &fixer::Mode,
     messages: &[Message],
     mode: &Mode,
 ) {

src/checks.rs

@@ -15,12 +15,19 @@ pub enum CheckCode {
     E713,
     E714,
     E731,
+    E741,
+    E742,
+    E743,
     E902,
     F401,
     F403,
+    F404,
+    F407,
     F541,
     F601,
     F602,
+    F621,
+    F622,
     F631,
     F634,
     F704,
@@ -48,12 +55,19 @@ impl FromStr for CheckCode {
             "E713" => Ok(CheckCode::E713),
             "E714" => Ok(CheckCode::E714),
             "E731" => Ok(CheckCode::E731),
+            "E741" => Ok(CheckCode::E741),
+            "E742" => Ok(CheckCode::E742),
+            "E743" => Ok(CheckCode::E743),
             "E902" => Ok(CheckCode::E902),
             "F401" => Ok(CheckCode::F401),
             "F403" => Ok(CheckCode::F403),
+            "F404" => Ok(CheckCode::F404),
+            "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),
             "F634" => Ok(CheckCode::F634),
             "F704" => Ok(CheckCode::F704),
@@ -82,12 +96,19 @@ impl CheckCode {
             CheckCode::E713 => "E713",
             CheckCode::E714 => "E714",
             CheckCode::E731 => "E731",
+            CheckCode::E741 => "E741",
+            CheckCode::E742 => "E742",
+            CheckCode::E743 => "E743",
             CheckCode::E902 => "E902",
             CheckCode::F401 => "F401",
             CheckCode::F403 => "F403",
+            CheckCode::F404 => "F404",
+            CheckCode::F407 => "F407",
             CheckCode::F541 => "F541",
             CheckCode::F601 => "F601",
             CheckCode::F602 => "F602",
+            CheckCode::F621 => "F621",
+            CheckCode::F622 => "F622",
             CheckCode::F631 => "F631",
             CheckCode::F634 => "F634",
             CheckCode::F704 => "F704",
@@ -114,12 +135,19 @@ impl CheckCode {
             CheckCode::E713 => &LintSource::AST,
             CheckCode::E714 => &LintSource::AST,
             CheckCode::E731 => &LintSource::AST,
+            CheckCode::E741 => &LintSource::AST,
+            CheckCode::E742 => &LintSource::AST,
+            CheckCode::E743 => &LintSource::AST,
             CheckCode::E902 => &LintSource::FileSystem,
             CheckCode::F401 => &LintSource::AST,
             CheckCode::F403 => &LintSource::AST,
+            CheckCode::F404 => &LintSource::AST,
+            CheckCode::F407 => &LintSource::AST,
             CheckCode::F541 => &LintSource::AST,
             CheckCode::F601 => &LintSource::AST,
             CheckCode::F602 => &LintSource::AST,
+            CheckCode::F621 => &LintSource::AST,
+            CheckCode::F622 => &LintSource::AST,
             CheckCode::F631 => &LintSource::AST,
             CheckCode::F634 => &LintSource::AST,
             CheckCode::F704 => &LintSource::AST,
@@ -153,13 +181,18 @@ pub enum RejectedCmpop {
 #[derive(Debug, PartialEq, Eq, Serialize, Deserialize)]
 pub enum CheckKind {
     AssertTuple,
+    AmbiguousVariableName(String),
+    AmbiguousClassName(String),
+    AmbiguousFunctionName(String),
     DefaultExceptNotLast,
     DoNotAssignLambda,
     DuplicateArgumentName,
     FStringMissingPlaceholders,
+    FutureFeatureNotDefined(String),
     IOError(String),
     IfTuple,
     ImportStarUsage,
+    LateFutureImport,
     LineTooLong,
     ModuleImportNotAtTopOfFile,
     MultiValueRepeatedKeyLiteral,
@@ -170,7 +203,9 @@ pub enum CheckKind {
     NotIsTest,
     RaiseNotImplemented,
     ReturnOutsideFunction,
+    TooManyExpressionsInStarredAssignment,
     TrueFalseComparison(bool, RejectedCmpop),
+    TwoStarredExpressions,
     UndefinedExport(String),
     UndefinedLocal(String),
     UndefinedName(String),
@@ -185,12 +220,17 @@ impl CheckKind {
     pub fn name(&self) -> &'static str {
         match self {
             CheckKind::AssertTuple => "AssertTuple",
+            CheckKind::AmbiguousVariableName(_) => "AmbiguousVariableName",
+            CheckKind::AmbiguousClassName(_) => "AmbiguousClassName",
+            CheckKind::AmbiguousFunctionName(_) => "AmbiguousFunctionName",
             CheckKind::DefaultExceptNotLast => "DefaultExceptNotLast",
             CheckKind::DuplicateArgumentName => "DuplicateArgumentName",
             CheckKind::FStringMissingPlaceholders => "FStringMissingPlaceholders",
+            CheckKind::FutureFeatureNotDefined(_) => "FutureFeatureNotDefined",
             CheckKind::IOError(_) => "IOError",
             CheckKind::IfTuple => "IfTuple",
             CheckKind::ImportStarUsage => "ImportStarUsage",
+            CheckKind::LateFutureImport => "LateFutureImport",
             CheckKind::LineTooLong => "LineTooLong",
             CheckKind::DoNotAssignLambda => "DoNotAssignLambda",
             CheckKind::ModuleImportNotAtTopOfFile => "ModuleImportNotAtTopOfFile",
@@ -202,7 +242,11 @@ impl CheckKind {
             CheckKind::NotIsTest => "NotIsTest",
             CheckKind::RaiseNotImplemented => "RaiseNotImplemented",
             CheckKind::ReturnOutsideFunction => "ReturnOutsideFunction",
+            CheckKind::TooManyExpressionsInStarredAssignment => {
+                "TooManyExpressionsInStarredAssignment"
+            }
             CheckKind::TrueFalseComparison(_, _) => "TrueFalseComparison",
+            CheckKind::TwoStarredExpressions => "TwoStarredExpressions",
             CheckKind::UndefinedExport(_) => "UndefinedExport",
             CheckKind::UndefinedLocal(_) => "UndefinedLocal",
             CheckKind::UndefinedName(_) => "UndefinedName",
@@ -220,11 +264,16 @@ impl CheckKind {
             CheckKind::DefaultExceptNotLast => &CheckCode::F707,
             CheckKind::DuplicateArgumentName => &CheckCode::F831,
             CheckKind::FStringMissingPlaceholders => &CheckCode::F541,
+            CheckKind::FutureFeatureNotDefined(_) => &CheckCode::F407,
             CheckKind::IOError(_) => &CheckCode::E902,
             CheckKind::IfTuple => &CheckCode::F634,
             CheckKind::ImportStarUsage => &CheckCode::F403,
+            CheckKind::LateFutureImport => &CheckCode::F404,
             CheckKind::LineTooLong => &CheckCode::E501,
             CheckKind::DoNotAssignLambda => &CheckCode::E731,
+            CheckKind::AmbiguousVariableName(_) => &CheckCode::E741,
+            CheckKind::AmbiguousClassName(_) => &CheckCode::E742,
+            CheckKind::AmbiguousFunctionName(_) => &CheckCode::E743,
             CheckKind::ModuleImportNotAtTopOfFile => &CheckCode::E402,
             CheckKind::MultiValueRepeatedKeyLiteral => &CheckCode::F601,
             CheckKind::MultiValueRepeatedKeyVariable(_) => &CheckCode::F602,
@@ -234,7 +283,9 @@ impl CheckKind {
             CheckKind::NotIsTest => &CheckCode::E714,
             CheckKind::RaiseNotImplemented => &CheckCode::F901,
             CheckKind::ReturnOutsideFunction => &CheckCode::F706,
+            CheckKind::TooManyExpressionsInStarredAssignment => &CheckCode::F621,
             CheckKind::TrueFalseComparison(_, _) => &CheckCode::E712,
+            CheckKind::TwoStarredExpressions => &CheckCode::F622,
             CheckKind::UndefinedExport(_) => &CheckCode::F822,
             CheckKind::UndefinedLocal(_) => &CheckCode::F823,
             CheckKind::UndefinedName(_) => &CheckCode::F821,
@@ -260,15 +311,30 @@ impl CheckKind {
             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::LateFutureImport => {
+                "from __future__ imports must occur at the beginning of the file".to_string()
+            }
             CheckKind::LineTooLong => "Line too long".to_string(),
             CheckKind::DoNotAssignLambda => {
                 "Do not assign a lambda expression, use a def".to_string()
             }
+            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::ModuleImportNotAtTopOfFile => {
                 "Module level import not at top of file".to_string()
             }
@@ -295,6 +361,9 @@ impl CheckKind {
             CheckKind::ReturnOutsideFunction => {
                 "a `return` statement outside of a function/method".to_string()
             }
+            CheckKind::TooManyExpressionsInStarredAssignment => {
+                "too many expressions in star-unpacking assignment".to_string()
+            }
             CheckKind::TrueFalseComparison(value, op) => match *value {
                 true => match op {
                     RejectedCmpop::Eq => {
@@ -313,6 +382,7 @@ impl CheckKind {
                     }
                 },
             },
+            CheckKind::TwoStarredExpressions => "two starred expressions in assignment".to_string(),
             CheckKind::UndefinedExport(name) => {
                 format!("Undefined name `{name}` in `__all__`")
             }
@@ -338,25 +408,32 @@ impl CheckKind {
     /// Whether the check kind is (potentially) fixable.
     pub fn fixable(&self) -> bool {
         match self {
+            CheckKind::AmbiguousClassName(_) => true,
+            CheckKind::AmbiguousFunctionName(_) => true,
+            CheckKind::AmbiguousVariableName(_) => false,
             CheckKind::AssertTuple => false,
             CheckKind::DefaultExceptNotLast => false,
+            CheckKind::DoNotAssignLambda => false,
             CheckKind::DuplicateArgumentName => false,
             CheckKind::FStringMissingPlaceholders => false,
+            CheckKind::FutureFeatureNotDefined(_) => false,
             CheckKind::IOError(_) => false,
             CheckKind::IfTuple => false,
             CheckKind::ImportStarUsage => false,
-            CheckKind::DoNotAssignLambda => false,
+            CheckKind::LateFutureImport => false,
             CheckKind::LineTooLong => false,
             CheckKind::ModuleImportNotAtTopOfFile => false,
             CheckKind::MultiValueRepeatedKeyLiteral => false,
             CheckKind::MultiValueRepeatedKeyVariable(_) => false,
             CheckKind::NoAssertEquals => true,
+            CheckKind::NoneComparison(_) => false,
             CheckKind::NotInTest => false,
             CheckKind::NotIsTest => false,
-            CheckKind::NoneComparison(_) => false,
             CheckKind::RaiseNotImplemented => false,
             CheckKind::ReturnOutsideFunction => false,
+            CheckKind::TooManyExpressionsInStarredAssignment => false,
             CheckKind::TrueFalseComparison(_, _) => false,
+            CheckKind::TwoStarredExpressions => false,
             CheckKind::UndefinedExport(_) => false,
             CheckKind::UndefinedLocal(_) => false,
             CheckKind::UndefinedName(_) => false,

src/lib.rs

@@ -1,18 +1,15 @@
 extern crate core;
 
-mod ast_ops;
+mod ast;
 mod autofix;
-mod builtins;
 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;
 mod pyproject;
-mod relocator;
+mod python;
 pub mod settings;
-mod visitor;

src/linter.rs

@@ -4,15 +4,16 @@ use anyhow::Result;
 use log::debug;
 use rustpython_parser::parser;
 
-use crate::autofix::fix_file;
+use crate::autofix::fixer;
+use crate::autofix::fixer::fix_file;
 use crate::check_ast::check_ast;
 use crate::check_lines::check_lines;
 use crate::checks::{Check, LintSource};
 use crate::message::Message;
 use crate::settings::Settings;
-use crate::{autofix, cache, fs};
+use crate::{cache, fs};
 
-fn check_path(path: &Path, settings: &Settings, autofix: &autofix::Mode) -> Result<Vec<Check>> {
+fn check_path(path: &Path, settings: &Settings, autofix: &fixer::Mode) -> Result<Vec<Check>> {
     // Read the file from disk.
     let contents = fs::read_file(path)?;
 
@@ -40,7 +41,7 @@ pub fn lint_path(
     path: &Path,
     settings: &Settings,
     mode: &cache::Mode,
-    autofix: &autofix::Mode,
+    autofix: &fixer::Mode,
 ) -> Result<Vec<Message>> {
     let metadata = path.metadata()?;
 
@@ -57,7 +58,7 @@ pub fn lint_path(
     let mut checks = check_path(path, settings, autofix)?;
 
     // Apply autofix.
-    if matches!(autofix, autofix::Mode::Apply) {
+    if matches!(autofix, fixer::Mode::Apply) {
         fix_file(&mut checks, &contents, path)?;
     };
 
@@ -84,9 +85,10 @@ mod tests {
     use anyhow::Result;
     use rustpython_parser::ast::Location;
 
+    use crate::autofix::fixer;
     use crate::checks::{Check, CheckCode, CheckKind, Fix, RejectedCmpop};
     use crate::linter::check_path;
-    use crate::{autofix, settings};
+    use crate::settings;
 
     #[test]
     fn e402() -> Result<()> {
@@ -97,7 +99,7 @@ mod tests {
                 exclude: vec![],
                 select: BTreeSet::from([CheckCode::E402]),
             },
-            &autofix::Mode::Generate,
+            &fixer::Mode::Generate,
         )?;
         actual.sort_by_key(|check| check.location);
         let expected = vec![Check {
@@ -122,7 +124,7 @@ mod tests {
                 exclude: vec![],
                 select: BTreeSet::from([CheckCode::E501]),
             },
-            &autofix::Mode::Generate,
+            &fixer::Mode::Generate,
         )?;
         actual.sort_by_key(|check| check.location);
         let expected = vec![Check {
@@ -147,7 +149,7 @@ mod tests {
                 exclude: vec![],
                 select: BTreeSet::from([CheckCode::E711]),
             },
-            &autofix::Mode::Generate,
+            &fixer::Mode::Generate,
         )?;
         actual.sort_by_key(|check| check.location);
         let expected = vec![
@@ -179,7 +181,7 @@ mod tests {
                 exclude: vec![],
                 select: BTreeSet::from([CheckCode::E712]),
             },
-            &autofix::Mode::Generate,
+            &fixer::Mode::Generate,
         )?;
         actual.sort_by_key(|check| check.location);
         let expected = vec![
@@ -222,7 +224,7 @@ mod tests {
                 exclude: vec![],
                 select: BTreeSet::from([CheckCode::E713]),
             },
-            &autofix::Mode::Generate,
+            &fixer::Mode::Generate,
         )?;
         actual.sort_by_key(|check| check.location);
         let expected = vec![Check {
@@ -247,7 +249,7 @@ mod tests {
                 exclude: vec![],
                 select: BTreeSet::from([CheckCode::E714]),
             },
-            &autofix::Mode::Generate,
+            &fixer::Mode::Generate,
         )?;
         actual.sort_by_key(|check| check.location);
         let expected = vec![Check {
@@ -272,7 +274,7 @@ mod tests {
                 exclude: vec![],
                 select: BTreeSet::from([CheckCode::E731]),
             },
-            &autofix::Mode::Generate,
+            &fixer::Mode::Generate,
         )?;
         actual.sort_by_key(|check| check.location);
         let expected = vec![
@@ -296,6 +298,225 @@ mod tests {
         Ok(())
     }
 
+    #[test]
+    fn e741() -> Result<()> {
+        let mut actual = check_path(
+            Path::new("./resources/test/fixtures/E741.py"),
+            &settings::Settings {
+                line_length: 88,
+                exclude: vec![],
+                select: BTreeSet::from([CheckCode::E741]),
+            },
+            &fixer::Mode::Generate,
+        )?;
+        actual.sort_by_key(|check| check.location);
+        let expected = vec![
+            Check {
+                kind: CheckKind::AmbiguousVariableName("l".to_string()),
+                location: Location::new(3, 1),
+                fix: None,
+            },
+            Check {
+                kind: CheckKind::AmbiguousVariableName("I".to_string()),
+                location: Location::new(4, 1),
+                fix: None,
+            },
+            Check {
+                kind: CheckKind::AmbiguousVariableName("O".to_string()),
+                location: Location::new(5, 1),
+                fix: None,
+            },
+            Check {
+                kind: CheckKind::AmbiguousVariableName("l".to_string()),
+                location: Location::new(6, 1),
+                fix: None,
+            },
+            Check {
+                kind: CheckKind::AmbiguousVariableName("l".to_string()),
+                location: Location::new(8, 4),
+                fix: None,
+            },
+            Check {
+                kind: CheckKind::AmbiguousVariableName("l".to_string()),
+                location: Location::new(9, 5),
+                fix: None,
+            },
+            Check {
+                kind: CheckKind::AmbiguousVariableName("l".to_string()),
+                location: Location::new(10, 5),
+                fix: None,
+            },
+            Check {
+                kind: CheckKind::AmbiguousVariableName("l".to_string()),
+                location: Location::new(11, 5),
+                fix: None,
+            },
+            Check {
+                kind: CheckKind::AmbiguousVariableName("l".to_string()),
+                location: Location::new(16, 5),
+                fix: None,
+            },
+            Check {
+                kind: CheckKind::AmbiguousVariableName("l".to_string()),
+                location: Location::new(20, 8),
+                fix: None,
+            },
+            Check {
+                kind: CheckKind::AmbiguousVariableName("l".to_string()),
+                location: Location::new(25, 5),
+                fix: None,
+            },
+            Check {
+                kind: CheckKind::AmbiguousVariableName("l".to_string()),
+                location: Location::new(26, 5),
+                fix: None,
+            },
+            Check {
+                kind: CheckKind::AmbiguousVariableName("l".to_string()),
+                location: Location::new(30, 5),
+                fix: None,
+            },
+            Check {
+                kind: CheckKind::AmbiguousVariableName("l".to_string()),
+                location: Location::new(33, 9),
+                fix: None,
+            },
+            Check {
+                kind: CheckKind::AmbiguousVariableName("l".to_string()),
+                location: Location::new(34, 9),
+                fix: None,
+            },
+            Check {
+                kind: CheckKind::AmbiguousVariableName("l".to_string()),
+                location: Location::new(40, 8),
+                fix: None,
+            },
+            Check {
+                kind: CheckKind::AmbiguousVariableName("I".to_string()),
+                location: Location::new(40, 14),
+                fix: None,
+            },
+            Check {
+                kind: CheckKind::AmbiguousVariableName("l".to_string()),
+                location: Location::new(44, 8),
+                fix: None,
+            },
+            Check {
+                kind: CheckKind::AmbiguousVariableName("I".to_string()),
+                location: Location::new(44, 16),
+                fix: None,
+            },
+            Check {
+                kind: CheckKind::AmbiguousVariableName("l".to_string()),
+                location: Location::new(48, 9),
+                fix: None,
+            },
+            Check {
+                kind: CheckKind::AmbiguousVariableName("I".to_string()),
+                location: Location::new(48, 14),
+                fix: None,
+            },
+            Check {
+                kind: CheckKind::AmbiguousVariableName("l".to_string()),
+                location: Location::new(57, 16),
+                fix: None,
+            },
+            Check {
+                kind: CheckKind::AmbiguousVariableName("l".to_string()),
+                location: Location::new(66, 20),
+                fix: None,
+            },
+            Check {
+                kind: CheckKind::AmbiguousVariableName("l".to_string()),
+                location: Location::new(71, 1),
+                fix: None,
+            },
+        ];
+
+        assert_eq!(actual.len(), expected.len());
+        for i in 0..actual.len() {
+            assert_eq!(actual[i], expected[i]);
+        }
+
+        Ok(())
+    }
+
+    #[test]
+    fn e742() -> Result<()> {
+        let mut actual = check_path(
+            Path::new("./resources/test/fixtures/E742.py"),
+            &settings::Settings {
+                line_length: 88,
+                exclude: vec![],
+                select: BTreeSet::from([CheckCode::E742]),
+            },
+            &fixer::Mode::Generate,
+        )?;
+        actual.sort_by_key(|check| check.location);
+        let expected = vec![
+            Check {
+                kind: CheckKind::AmbiguousClassName("l".to_string()),
+                location: Location::new(1, 1),
+                fix: None,
+            },
+            Check {
+                kind: CheckKind::AmbiguousClassName("I".to_string()),
+                location: Location::new(5, 1),
+                fix: None,
+            },
+            Check {
+                kind: CheckKind::AmbiguousClassName("O".to_string()),
+                location: Location::new(9, 1),
+                fix: None,
+            },
+        ];
+
+        assert_eq!(actual.len(), expected.len());
+        for i in 0..actual.len() {
+            assert_eq!(actual[i], expected[i]);
+        }
+
+        Ok(())
+    }
+
+    #[test]
+    fn e743() -> Result<()> {
+        let mut actual = check_path(
+            Path::new("./resources/test/fixtures/E743.py"),
+            &settings::Settings {
+                line_length: 88,
+                exclude: vec![],
+                select: BTreeSet::from([CheckCode::E743]),
+            },
+            &fixer::Mode::Generate,
+        )?;
+        actual.sort_by_key(|check| check.location);
+        let expected = vec![
+            Check {
+                kind: CheckKind::AmbiguousFunctionName("l".to_string()),
+                location: Location::new(1, 1),
+                fix: None,
+            },
+            Check {
+                kind: CheckKind::AmbiguousFunctionName("I".to_string()),
+                location: Location::new(5, 1),
+                fix: None,
+            },
+            Check {
+                kind: CheckKind::AmbiguousFunctionName("O".to_string()),
+                location: Location::new(10, 5),
+                fix: None,
+            },
+        ];
+
+        assert_eq!(actual.len(), expected.len());
+        for i in 0..actual.len() {
+            assert_eq!(actual[i], expected[i]);
+        }
+
+        Ok(())
+    }
+
     #[test]
     fn f401() -> Result<()> {
         let mut actual = check_path(
@@ -305,7 +526,7 @@ mod tests {
                 exclude: vec![],
                 select: BTreeSet::from([CheckCode::F401]),
             },
-            &autofix::Mode::Generate,
+            &fixer::Mode::Generate,
         )?;
         actual.sort_by_key(|check| check.location);
         let expected = vec![
@@ -342,7 +563,7 @@ mod tests {
                 exclude: vec![],
                 select: BTreeSet::from([CheckCode::F403]),
             },
-            &autofix::Mode::Generate,
+            &fixer::Mode::Generate,
         )?;
         actual.sort_by_key(|check| check.location);
         let expected = vec![
@@ -364,6 +585,57 @@ mod tests {
 
         Ok(())
     }
+
+    #[test]
+    fn f404() -> Result<()> {
+        let mut actual = check_path(
+            Path::new("./resources/test/fixtures/F404.py"),
+            &settings::Settings {
+                line_length: 88,
+                exclude: vec![],
+                select: BTreeSet::from([CheckCode::F404]),
+            },
+            &fixer::Mode::Generate,
+        )?;
+        actual.sort_by_key(|check| check.location);
+        let expected = vec![Check {
+            kind: CheckKind::LateFutureImport,
+            location: Location::new(7, 1),
+            fix: None,
+        }];
+        assert_eq!(actual.len(), expected.len());
+        for i in 0..actual.len() {
+            assert_eq!(actual[i], expected[i]);
+        }
+
+        Ok(())
+    }
+
+    #[test]
+    fn f407() -> Result<()> {
+        let mut actual = check_path(
+            Path::new("./resources/test/fixtures/F407.py"),
+            &settings::Settings {
+                line_length: 88,
+                exclude: vec![],
+                select: BTreeSet::from([CheckCode::F407]),
+            },
+            &fixer::Mode::Generate,
+        )?;
+        actual.sort_by_key(|check| check.location);
+        let expected = vec![Check {
+            kind: CheckKind::FutureFeatureNotDefined("non_existent_feature".to_string()),
+            location: Location::new(2, 1),
+            fix: None,
+        }];
+        assert_eq!(actual.len(), expected.len());
+        for i in 0..actual.len() {
+            assert_eq!(actual[i], expected[i]);
+        }
+
+        Ok(())
+    }
+
     #[test]
     fn f541() -> Result<()> {
         let mut actual = check_path(
@@ -373,7 +645,7 @@ mod tests {
                 exclude: vec![],
                 select: BTreeSet::from([CheckCode::F541]),
             },
-            &autofix::Mode::Generate,
+            &fixer::Mode::Generate,
         )?;
         actual.sort_by_key(|check| check.location);
         let expected = vec![
@@ -410,7 +682,7 @@ mod tests {
                 exclude: vec![],
                 select: BTreeSet::from([CheckCode::F601]),
             },
-            &autofix::Mode::Generate,
+            &fixer::Mode::Generate,
         )?;
         let expected = vec![
             Check {
@@ -446,7 +718,7 @@ mod tests {
                 exclude: vec![],
                 select: BTreeSet::from([CheckCode::F602]),
             },
-            &autofix::Mode::Generate,
+            &fixer::Mode::Generate,
         )?;
         let expected = vec![Check {
             kind: CheckKind::MultiValueRepeatedKeyVariable("a".to_string()),
@@ -461,6 +733,30 @@ mod tests {
         Ok(())
     }
 
+    #[test]
+    fn f622() -> Result<()> {
+        let actual = check_path(
+            Path::new("./resources/test/fixtures/F622.py"),
+            &settings::Settings {
+                line_length: 88,
+                exclude: vec![],
+                select: BTreeSet::from([CheckCode::F622]),
+            },
+            &fixer::Mode::Generate,
+        )?;
+        let expected = vec![Check {
+            kind: CheckKind::TwoStarredExpressions,
+            location: Location::new(1, 1),
+            fix: None,
+        }];
+        assert_eq!(actual.len(), expected.len());
+        for i in 0..actual.len() {
+            assert_eq!(actual[i], expected[i]);
+        }
+
+        Ok(())
+    }
+
     #[test]
     fn f631() -> Result<()> {
         let mut actual = check_path(
@@ -470,7 +766,7 @@ mod tests {
                 exclude: vec![],
                 select: BTreeSet::from([CheckCode::F631]),
             },
-            &autofix::Mode::Generate,
+            &fixer::Mode::Generate,
         )?;
         actual.sort_by_key(|check| check.location);
         let expected = vec![
@@ -502,7 +798,7 @@ mod tests {
                 exclude: vec![],
                 select: BTreeSet::from([CheckCode::F634]),
             },
-            &autofix::Mode::Generate,
+            &fixer::Mode::Generate,
         )?;
         actual.sort_by_key(|check| check.location);
         let expected = vec![
@@ -534,7 +830,7 @@ mod tests {
                 exclude: vec![],
                 select: BTreeSet::from([CheckCode::F704]),
             },
-            &autofix::Mode::Generate,
+            &fixer::Mode::Generate,
         )?;
         actual.sort_by_key(|check| check.location);
         let expected = vec![
@@ -571,7 +867,7 @@ mod tests {
                 exclude: vec![],
                 select: BTreeSet::from([CheckCode::F706]),
             },
-            &autofix::Mode::Generate,
+            &fixer::Mode::Generate,
         )?;
         actual.sort_by_key(|check| check.location);
         let expected = vec![
@@ -603,7 +899,7 @@ mod tests {
                 exclude: vec![],
                 select: BTreeSet::from([CheckCode::F707]),
             },
-            &autofix::Mode::Generate,
+            &fixer::Mode::Generate,
         )?;
         actual.sort_by_key(|check| check.location);
         let expected = vec![
@@ -640,7 +936,7 @@ mod tests {
                 exclude: vec![],
                 select: BTreeSet::from([CheckCode::F821]),
             },
-            &autofix::Mode::Generate,
+            &fixer::Mode::Generate,
         )?;
         actual.sort_by_key(|check| check.location);
         let expected = vec![
@@ -687,7 +983,7 @@ mod tests {
                 exclude: vec![],
                 select: BTreeSet::from([CheckCode::F822]),
             },
-            &autofix::Mode::Generate,
+            &fixer::Mode::Generate,
         )?;
         actual.sort_by_key(|check| check.location);
         let expected = vec![Check {
@@ -712,7 +1008,7 @@ mod tests {
                 exclude: vec![],
                 select: BTreeSet::from([CheckCode::F823]),
             },
-            &autofix::Mode::Generate,
+            &fixer::Mode::Generate,
         )?;
         actual.sort_by_key(|check| check.location);
         let expected = vec![Check {
@@ -737,7 +1033,7 @@ mod tests {
                 exclude: vec![],
                 select: BTreeSet::from([CheckCode::F831]),
             },
-            &autofix::Mode::Generate,
+            &fixer::Mode::Generate,
         )?;
         actual.sort_by_key(|check| check.location);
         let expected = vec![
@@ -774,7 +1070,7 @@ mod tests {
                 exclude: vec![],
                 select: BTreeSet::from([CheckCode::F841]),
             },
-            &autofix::Mode::Generate,
+            &fixer::Mode::Generate,
         )?;
         actual.sort_by_key(|check| check.location);
         let expected = vec![
@@ -788,6 +1084,21 @@ mod tests {
                 location: Location::new(16, 5),
                 fix: None,
             },
+            Check {
+                kind: CheckKind::UnusedVariable("foo".to_string()),
+                location: Location::new(20, 5),
+                fix: None,
+            },
+            Check {
+                kind: CheckKind::UnusedVariable("a".to_string()),
+                location: Location::new(21, 6),
+                fix: None,
+            },
+            Check {
+                kind: CheckKind::UnusedVariable("b".to_string()),
+                location: Location::new(21, 9),
+                fix: None,
+            },
         ];
         assert_eq!(actual.len(), expected.len());
         for i in 0..actual.len() {
@@ -806,18 +1117,18 @@ mod tests {
                 exclude: vec![],
                 select: BTreeSet::from([CheckCode::F901]),
             },
-            &autofix::Mode::Generate,
+            &fixer::Mode::Generate,
         )?;
         actual.sort_by_key(|check| check.location);
         let expected = vec![
             Check {
                 kind: CheckKind::RaiseNotImplemented,
-                location: Location::new(2, 5),
+                location: Location::new(2, 25),
                 fix: None,
             },
             Check {
                 kind: CheckKind::RaiseNotImplemented,
-                location: Location::new(6, 5),
+                location: Location::new(6, 11),
                 fix: None,
             },
         ];
@@ -838,7 +1149,7 @@ mod tests {
                 exclude: vec![],
                 select: BTreeSet::from([CheckCode::R001]),
             },
-            &autofix::Mode::Generate,
+            &fixer::Mode::Generate,
         )?;
         actual.sort_by_key(|check| check.location);
         let expected = vec![
@@ -1060,13 +1371,13 @@ mod tests {
                 exclude: vec![],
                 select: BTreeSet::from([CheckCode::R002]),
             },
-            &autofix::Mode::Generate,
+            &fixer::Mode::Generate,
         )?;
         actual.sort_by_key(|check| check.location);
         let expected = vec![
             Check {
                 kind: CheckKind::NoAssertEquals,
-                location: Location::new(1, 19),
+                location: Location::new(1, 5),
                 fix: Some(Fix {
                     content: "assertEqual".to_string(),
                     start: Location::new(1, 6),
@@ -1076,7 +1387,7 @@ mod tests {
             },
             Check {
                 kind: CheckKind::NoAssertEquals,
-                location: Location::new(2, 18),
+                location: Location::new(2, 5),
                 fix: Some(Fix {
                     content: "assertEqual".to_string(),
                     start: Location::new(2, 6),

src/main.rs

@@ -6,6 +6,7 @@ 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::*;
@@ -47,12 +48,15 @@ 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 file and/or directory patterns to exclude from checks.
+    #[clap(long, multiple = true)]
+    exclude: Vec<Pattern>,
 }
 
 #[cfg(feature = "update-informer")]
@@ -188,6 +192,9 @@ fn inner_main() -> Result<ExitCode> {
     if !cli.ignore.is_empty() {
         settings.ignore(&cli.ignore);
     }
+    if !cli.exclude.is_empty() {
+        settings.exclude(cli.exclude);
+    }
 
     if cli.watch {
         if cli.fix {

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(),
         ))
     }
 }

src/pyproject.rs

@@ -266,12 +266,19 @@ other-attribute = 1
                     CheckCode::E713,
                     CheckCode::E714,
                     CheckCode::E731,
+                    CheckCode::E741,
+                    CheckCode::E742,
+                    CheckCode::E743,
                     CheckCode::E902,
                     CheckCode::F401,
                     CheckCode::F403,
+                    CheckCode::F404,
+                    CheckCode::F407,
                     CheckCode::F541,
                     CheckCode::F601,
                     CheckCode::F602,
+                    CheckCode::F621,
+                    CheckCode::F622,
                     CheckCode::F631,
                     CheckCode::F634,
                     CheckCode::F704,

src/python.rs

@@ -0,0 +1,3 @@
+pub mod builtins;
+pub mod future;
+pub mod typing;

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__",
 ];

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",
+];

src/python/typing.rs

@@ -0,0 +1,88 @@
+use lazy_static::lazy_static;
+use std::collections::BTreeSet;
+
+lazy_static! {
+    static ref ANNOTATED_SUBSCRIPTS: BTreeSet<&'static str> = 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)
+}

src/settings.rs

@@ -51,12 +51,18 @@ impl Settings {
                     CheckCode::E713,
                     CheckCode::E714,
                     CheckCode::E731,
+                    CheckCode::E741,
+                    CheckCode::E742,
+                    CheckCode::E743,
                     CheckCode::E902,
                     CheckCode::F401,
                     CheckCode::F403,
+                    CheckCode::F407,
                     CheckCode::F541,
                     CheckCode::F601,
                     CheckCode::F602,
+                    CheckCode::F621,
+                    CheckCode::F622,
                     CheckCode::F631,
                     CheckCode::F634,
                     CheckCode::F704,
@@ -92,4 +98,8 @@ impl Settings {
             self.select.remove(code);
         }
     }
+
+    pub fn exclude(&mut self, exclude: Vec<Pattern>) {
+        self.exclude = exclude;
+    }
 }