Avoid A003 violations for explicitly overridden methods (#6076)

## Summary

If a method is annotated with `@typing_extensions.override`, we should
avoid flagging A003 on it. This isn't part of the standard library yet,
but it's used to explicitly mark methods as overrides.

crates/ruff/resources/test/fixtures/flake8_builtins/A003.py

@@ -39,3 +39,15 @@ class CustomFilter(Filter):
 
     def str(self) -> None:
         ...
+
+
+from typing_extensions import override
+
+
+class MyClass:
+    @override
+    def str(self):
+        pass
+
+    def int(self):
+        pass

crates/ruff/src/checkers/ast/analyze/statement.rs

@@ -332,10 +332,11 @@ pub(crate) fn statement(stmt: &Stmt, checker: &mut Checker) {
             }
             if let ScopeKind::Class(class_def) = checker.semantic.scope().kind {
                 if checker.enabled(Rule::BuiltinAttributeShadowing) {
-                    flake8_builtins::rules::builtin_attribute_shadowing(
+                    flake8_builtins::rules::builtin_method_shadowing(
                         checker,
                         class_def,
                         name,
+                        decorator_list,
                         name.range(),
                     );
                 }

crates/ruff/src/rules/flake8_builtins/rules/builtin_attribute_shadowing.rs

@@ -1,5 +1,6 @@
 use ruff_text_size::TextRange;
 use rustpython_parser::ast;
+use rustpython_parser::ast::Decorator;
 
 use ruff_diagnostics::Diagnostic;
 use ruff_diagnostics::Violation;
@@ -10,7 +11,8 @@ use crate::checkers::ast::Checker;
 use crate::rules::flake8_builtins::helpers::shadows_builtin;
 
 /// ## What it does
-/// Checks for any class attributes that use the same name as a builtin.
+/// Checks for any class attributes or methods that use the same name as a
+/// builtin.
 ///
 /// ## Why is this bad?
 /// Reusing a builtin name for the name of an attribute increases the
@@ -20,7 +22,9 @@ use crate::rules::flake8_builtins::helpers::shadows_builtin;
 ///
 /// Builtins can be marked as exceptions to this rule via the
 /// [`flake8-builtins.builtins-ignorelist`] configuration option, or
-/// converted to the appropriate dunder method.
+/// converted to the appropriate dunder method. Methods decorated with
+/// `@typing.override` or `@typing_extensions.override` are also
+/// ignored.
 ///
 /// ## Example
 /// ```python
@@ -81,12 +85,39 @@ pub(crate) fn builtin_attribute_shadowing(
             return;
         }
 
+        checker.diagnostics.push(Diagnostic::new(
+            BuiltinAttributeShadowing {
+                name: name.to_string(),
+            },
+            range,
+        ));
+    }
+}
+
+/// A003
+pub(crate) fn builtin_method_shadowing(
+    checker: &mut Checker,
+    class_def: &ast::StmtClassDef,
+    name: &str,
+    decorator_list: &[Decorator],
+    range: TextRange,
+) {
+    if shadows_builtin(name, &checker.settings.flake8_builtins.builtins_ignorelist) {
         // Ignore some standard-library methods. Ideally, we'd ignore all overridden methods, since
         // those should be flagged on the superclass, but that's more difficult.
         if is_standard_library_override(name, class_def, checker.semantic()) {
             return;
         }
 
+        // Ignore explicit overrides.
+        if decorator_list.iter().any(|decorator| {
+            checker
+                .semantic()
+                .match_typing_expr(&decorator.expression, "override")
+        }) {
+            return;
+        }
+
         checker.diagnostics.push(Diagnostic::new(
             BuiltinAttributeShadowing {
                 name: name.to_string(),

crates/ruff/src/rules/flake8_builtins/snapshots/ruff__rules__flake8_builtins__tests__A003_A003.py.snap

@@ -56,4 +56,13 @@ A003.py:40:9: A003 Class attribute `str` is shadowing a Python builtin
 41 |         ...
    |
 
+A003.py:52:9: A003 Class attribute `int` is shadowing a Python builtin
+   |
+50 |         pass
+51 | 
+52 |     def int(self):
+   |         ^^^ A003
+53 |         pass
+   |
+
 

crates/ruff/src/rules/flake8_builtins/snapshots/ruff__rules__flake8_builtins__tests__A003_A003.py_builtins_ignorelist.snap

@@ -37,4 +37,13 @@ A003.py:40:9: A003 Class attribute `str` is shadowing a Python builtin
 41 |         ...
    |
 
+A003.py:52:9: A003 Class attribute `int` is shadowing a Python builtin
+   |
+50 |         pass
+51 | 
+52 |     def int(self):
+   |         ^^^ A003
+53 |         pass
+   |
+