Handle decorators in class-parenthesis-modifying rules (#5034)

## Summary

A few of our rules look at the parentheses that follow a class
definition (e.g., `class Foo(object):`) and attempt to modify those
parentheses. Neither of those rules were behaving properly in the
presence of decorators, which were recently added to the statement
range.

## Test Plan

`cargo test` with a variety of new fixture tests.

crates/ruff/resources/test/fixtures/pyupgrade/UP004.py

@@ -134,6 +134,19 @@ class A(
     ...
 
 
+class A(object, object):
+    ...
+
+
+@decorator()
+class A(object):
+    ...
+
+@decorator()  # class A(object):
+class A(object):
+    ...
+
+
 object = A
 
 

crates/ruff/resources/test/fixtures/pyupgrade/UP039.py

@@ -13,6 +13,14 @@ class A \
     pass
 
 
+@decorator()
+class A():
+    pass
+
+@decorator
+class A():
+    pass
+
 # OK
 class A:
     pass
@@ -24,3 +32,12 @@ class A(A):
 
 class A(metaclass=type):
     pass
+
+
+@decorator()
+class A:
+    pass
+
+@decorator
+class A:
+    pass

crates/ruff/src/checkers/ast/mod.rs

@@ -727,10 +727,10 @@ where
                     pylint::rules::global_statement(self, name);
                 }
                 if self.enabled(Rule::UselessObjectInheritance) {
-                    pyupgrade::rules::useless_object_inheritance(self, stmt, name, bases, keywords);
+                    pyupgrade::rules::useless_object_inheritance(self, class_def, stmt);
                 }
                 if self.enabled(Rule::UnnecessaryClassParentheses) {
-                    pyupgrade::rules::unnecessary_class_parentheses(self, class_def);
+                    pyupgrade::rules::unnecessary_class_parentheses(self, class_def, stmt);
                 }
 
                 if self.enabled(Rule::AmbiguousClassName) {

crates/ruff/src/rules/pyupgrade/rules/unnecessary_class_parentheses.rs

@@ -1,10 +1,11 @@
 use std::ops::Add;
 
 use ruff_text_size::{TextRange, TextSize};
-use rustpython_parser::ast::{self};
+use rustpython_parser::ast::{self, Stmt};
 
 use ruff_diagnostics::{AlwaysAutofixableViolation, Diagnostic, Edit, Fix};
 use ruff_macros::{derive_message_formats, violation};
+use ruff_python_ast::helpers::identifier_range;
 
 use crate::checkers::ast::Checker;
 use crate::registry::AsRule;
@@ -43,12 +44,17 @@ impl AlwaysAutofixableViolation for UnnecessaryClassParentheses {
 }
 
 /// UP039
-pub(crate) fn unnecessary_class_parentheses(checker: &mut Checker, class_def: &ast::StmtClassDef) {
+pub(crate) fn unnecessary_class_parentheses(
+    checker: &mut Checker,
+    class_def: &ast::StmtClassDef,
+    stmt: &Stmt,
+) {
     if !class_def.bases.is_empty() || !class_def.keywords.is_empty() {
         return;
     }
 
-    let contents = checker.locator.slice(class_def.range);
+    let offset = identifier_range(stmt, checker.locator).start();
+    let contents = checker.locator.after(offset);
 
     // Find the open and closing parentheses between the class name and the colon, if they exist.
     let mut depth = 0u32;
@@ -85,8 +91,8 @@ pub(crate) fn unnecessary_class_parentheses(checker: &mut Checker, class_def: &a
     let end = TextSize::try_from(end).unwrap();
 
     // Add initial offset.
-    let start = class_def.range.start().add(start);
+    let start = offset.add(start);
-    let end = class_def.range.start().add(end);
+    let end = offset.add(end);
 
     let mut diagnostic = Diagnostic::new(UnnecessaryClassParentheses, TextRange::new(start, end));
     if checker.patch(diagnostic.kind.rule()) {

crates/ruff/src/rules/pyupgrade/rules/useless_object_inheritance.rs

@@ -1,9 +1,8 @@
-use rustpython_parser::ast::{self, Expr, Keyword, Ranged, Stmt};
+use rustpython_parser::ast::{self, Expr, Ranged, Stmt};
 
-use ruff_diagnostics::{AlwaysAutofixableViolation, Diagnostic};
+use ruff_diagnostics::{AlwaysAutofixableViolation, Diagnostic, Fix};
 use ruff_macros::{derive_message_formats, violation};
-use ruff_python_semantic::binding::{Binding, BindingKind, Bindings};
+use ruff_python_ast::helpers::identifier_range;
-use ruff_python_semantic::scope::Scope;
 
 use crate::autofix::edits::remove_argument;
 use crate::checkers::ast::Checker;
@@ -26,62 +25,40 @@ impl AlwaysAutofixableViolation for UselessObjectInheritance {
     }
 }
 
-fn rule(name: &str, bases: &[Expr], scope: &Scope, bindings: &Bindings) -> Option<Diagnostic> {
+/// UP004
-    for expr in bases {
+pub(crate) fn useless_object_inheritance(
+    checker: &mut Checker,
+    class_def: &ast::StmtClassDef,
+    stmt: &Stmt,
+) {
+    for expr in &class_def.bases {
         let Expr::Name(ast::ExprName { id, .. }) = expr else {
             continue;
         };
         if id != "object" {
             continue;
         }
-        if !matches!(
+        if !checker.semantic_model().is_builtin("object") {
-            scope
-                .get(id.as_str())
-                .map(|binding_id| &bindings[binding_id]),
-            None | Some(Binding {
-                kind: BindingKind::Builtin,
-                ..
-            })
-        ) {
             continue;
         }
-        return Some(Diagnostic::new(
+
+        let mut diagnostic = Diagnostic::new(
             UselessObjectInheritance {
-                name: name.to_string(),
+                name: class_def.name.to_string(),
             },
             expr.range(),
-        ));
+        );
-    }
-
-    None
-}
-
-/// UP004
-pub(crate) fn useless_object_inheritance(
-    checker: &mut Checker,
-    stmt: &Stmt,
-    name: &str,
-    bases: &[Expr],
-    keywords: &[Keyword],
-) {
-    if let Some(mut diagnostic) = rule(
-        name,
-        bases,
-        checker.semantic_model().scope(),
-        &checker.semantic_model().bindings,
-    ) {
         if checker.patch(diagnostic.kind.rule()) {
-            let expr_range = diagnostic.range();
+            diagnostic.try_set_fix(|| {
-            #[allow(deprecated)]
+                let edit = remove_argument(
-            diagnostic.try_set_fix_from_edit(|| {
-                remove_argument(
                     checker.locator,
-                    stmt.start(),
+                    identifier_range(stmt, checker.locator).start(),
-                    expr_range,
+                    expr.range(),
-                    bases,
+                    &class_def.bases,
-                    keywords,
+                    &class_def.keywords,
                     true,
-                )
+                )?;
+                Ok(Fix::automatic(edit))
             });
         }
         checker.diagnostics.push(diagnostic);

crates/ruff/src/rules/pyupgrade/snapshots/ruff__rules__pyupgrade__tests__UP004.py.snap

@@ -9,7 +9,7 @@ UP004.py:5:9: UP004 [*] Class `A` inherits from `object`
   |
   = help: Remove `object` inheritance
 
-ℹ Suggested fix
+ℹ Fix
 2 2 |     ...
 3 3 | 
 4 4 | 
@@ -29,7 +29,7 @@ UP004.py:10:5: UP004 [*] Class `A` inherits from `object`
    |
    = help: Remove `object` inheritance
 
-ℹ Suggested fix
+ℹ Fix
 6  6  |     ...
 7  7  | 
 8  8  | 
@@ -51,7 +51,7 @@ UP004.py:16:5: UP004 [*] Class `A` inherits from `object`
    |
    = help: Remove `object` inheritance
 
-ℹ Suggested fix
+ℹ Fix
 12 12 |     ...
 13 13 | 
 14 14 | 
@@ -75,7 +75,7 @@ UP004.py:24:5: UP004 [*] Class `A` inherits from `object`
    |
    = help: Remove `object` inheritance
 
-ℹ Suggested fix
+ℹ Fix
 19 19 |     ...
 20 20 | 
 21 21 | 
@@ -99,7 +99,7 @@ UP004.py:31:5: UP004 [*] Class `A` inherits from `object`
    |
    = help: Remove `object` inheritance
 
-ℹ Suggested fix
+ℹ Fix
 26 26 |     ...
 27 27 | 
 28 28 | 
@@ -122,7 +122,7 @@ UP004.py:37:5: UP004 [*] Class `A` inherits from `object`
    |
    = help: Remove `object` inheritance
 
-ℹ Suggested fix
+ℹ Fix
 33 33 |     ...
 34 34 | 
 35 35 | 
@@ -146,7 +146,7 @@ UP004.py:45:5: UP004 [*] Class `A` inherits from `object`
    |
    = help: Remove `object` inheritance
 
-ℹ Suggested fix
+ℹ Fix
 40 40 |     ...
 41 41 | 
 42 42 | 
@@ -171,7 +171,7 @@ UP004.py:53:5: UP004 [*] Class `A` inherits from `object`
    |
    = help: Remove `object` inheritance
 
-ℹ Suggested fix
+ℹ Fix
 48 48 |     ...
 49 49 | 
 50 50 | 
@@ -196,7 +196,7 @@ UP004.py:61:5: UP004 [*] Class `A` inherits from `object`
    |
    = help: Remove `object` inheritance
 
-ℹ Suggested fix
+ℹ Fix
 56 56 |     ...
 57 57 | 
 58 58 | 
@@ -221,7 +221,7 @@ UP004.py:69:5: UP004 [*] Class `A` inherits from `object`
    |
    = help: Remove `object` inheritance
 
-ℹ Suggested fix
+ℹ Fix
 64 64 |     ...
 65 65 | 
 66 66 | 
@@ -243,7 +243,7 @@ UP004.py:75:12: UP004 [*] Class `B` inherits from `object`
    |
    = help: Remove `object` inheritance
 
-ℹ Suggested fix
+ℹ Fix
 72 72 |     ...
 73 73 | 
 74 74 | 
@@ -261,7 +261,7 @@ UP004.py:79:9: UP004 [*] Class `B` inherits from `object`
    |
    = help: Remove `object` inheritance
 
-ℹ Suggested fix
+ℹ Fix
 76 76 |     ...
 77 77 | 
 78 78 | 
@@ -281,7 +281,7 @@ UP004.py:84:5: UP004 [*] Class `B` inherits from `object`
    |
    = help: Remove `object` inheritance
 
-ℹ Suggested fix
+ℹ Fix
 81 81 | 
 82 82 | 
 83 83 | class B(
@@ -301,7 +301,7 @@ UP004.py:92:5: UP004 [*] Class `B` inherits from `object`
    |
    = help: Remove `object` inheritance
 
-ℹ Suggested fix
+ℹ Fix
 89 89 | 
 90 90 | class B(
 91 91 |     A,
@@ -320,7 +320,7 @@ UP004.py:98:5: UP004 [*] Class `B` inherits from `object`
     |
     = help: Remove `object` inheritance
 
-ℹ Suggested fix
+ℹ Fix
 95 95 | 
 96 96 | 
 97 97 | class B(
@@ -340,7 +340,7 @@ UP004.py:108:5: UP004 [*] Class `B` inherits from `object`
     |
     = help: Remove `object` inheritance
 
-ℹ Suggested fix
+ℹ Fix
 105 105 | class B(
 106 106 |     # Comment on A.
 107 107 |     A,
@@ -349,25 +349,6 @@ UP004.py:108:5: UP004 [*] Class `B` inherits from `object`
 110 109 |     ...
 111 110 | 
 
-UP004.py:114:13: UP004 [*] Class `A` inherits from `object`
-    |
-113 | def f():
-114 |     class A(object):
-    |             ^^^^^^ UP004
-115 |         ...
-    |
-    = help: Remove `object` inheritance
-
-ℹ Suggested fix
-111 111 | 
-112 112 | 
-113 113 | def f():
-114     |-    class A(object):
-    114 |+    class A:
-115 115 |         ...
-116 116 | 
-117 117 | 
-
 UP004.py:119:5: UP004 [*] Class `A` inherits from `object`
     |
 118 | class A(
@@ -378,7 +359,7 @@ UP004.py:119:5: UP004 [*] Class `A` inherits from `object`
     |
     = help: Remove `object` inheritance
 
-ℹ Suggested fix
+ℹ Fix
 115 115 |         ...
 116 116 | 
 117 117 | 
@@ -400,7 +381,7 @@ UP004.py:125:5: UP004 [*] Class `A` inherits from `object`
     |
     = help: Remove `object` inheritance
 
-ℹ Suggested fix
+ℹ Fix
 121 121 |     ...
 122 122 | 
 123 123 | 
@@ -422,7 +403,7 @@ UP004.py:131:5: UP004 [*] Class `A` inherits from `object`
     |
     = help: Remove `object` inheritance
 
-ℹ Suggested fix
+ℹ Fix
 127 127 |     ...
 128 128 | 
 129 129 | 
@@ -435,4 +416,78 @@ UP004.py:131:5: UP004 [*] Class `A` inherits from `object`
 135 132 | 
 136 133 | 
 
+UP004.py:137:9: UP004 [*] Class `A` inherits from `object`
+    |
+137 | class A(object, object):
+    |         ^^^^^^ UP004
+138 |     ...
+    |
+    = help: Remove `object` inheritance
+
+ℹ Fix
+134 134 |     ...
+135 135 | 
+136 136 | 
+137     |-class A(object, object):
+    137 |+class A(object):
+138 138 |     ...
+139 139 | 
+140 140 | 
+
+UP004.py:137:17: UP004 [*] Class `A` inherits from `object`
+    |
+137 | class A(object, object):
+    |                 ^^^^^^ UP004
+138 |     ...
+    |
+    = help: Remove `object` inheritance
+
+ℹ Fix
+134 134 |     ...
+135 135 | 
+136 136 | 
+137     |-class A(object, object):
+    137 |+class A(object):
+138 138 |     ...
+139 139 | 
+140 140 | 
+
+UP004.py:142:9: UP004 [*] Class `A` inherits from `object`
+    |
+141 | @decorator()
+142 | class A(object):
+    |         ^^^^^^ UP004
+143 |     ...
+    |
+    = help: Remove `object` inheritance
+
+ℹ Fix
+139 139 | 
+140 140 | 
+141 141 | @decorator()
+142     |-class A(object):
+    142 |+class A:
+143 143 |     ...
+144 144 | 
+145 145 | @decorator()  # class A(object):
+
+UP004.py:146:9: UP004 [*] Class `A` inherits from `object`
+    |
+145 | @decorator()  # class A(object):
+146 | class A(object):
+    |         ^^^^^^ UP004
+147 |     ...
+    |
+    = help: Remove `object` inheritance
+
+ℹ Fix
+143 143 |     ...
+144 144 | 
+145 145 | @decorator()  # class A(object):
+146     |-class A(object):
+    146 |+class A:
+147 147 |     ...
+148 148 | 
+149 149 | 
+
 

crates/ruff/src/rules/pyupgrade/snapshots/ruff__rules__pyupgrade__tests__UP039.py.snap

@@ -56,4 +56,42 @@ UP039.py:12:9: UP039 [*] Unnecessary parentheses after class definition
 14 14 | 
 15 15 | 
 
+UP039.py:17:8: UP039 [*] Unnecessary parentheses after class definition
+   |
+16 | @decorator()
+17 | class A():
+   |        ^^ UP039
+18 |     pass
+   |
+   = help: Remove parentheses
+
+ℹ Fix
+14 14 | 
+15 15 | 
+16 16 | @decorator()
+17    |-class A():
+   17 |+class A:
+18 18 |     pass
+19 19 | 
+20 20 | @decorator
+
+UP039.py:21:8: UP039 [*] Unnecessary parentheses after class definition
+   |
+20 | @decorator
+21 | class A():
+   |        ^^ UP039
+22 |     pass
+   |
+   = help: Remove parentheses
+
+ℹ Fix
+18 18 |     pass
+19 19 | 
+20 20 | @decorator
+21    |-class A():
+   21 |+class A:
+22 22 |     pass
+23 23 | 
+24 24 | # OK
+