Omit unrolled augmented assignments in PIE794

crates/ruff_linter/resources/test/fixtures/flake8_pie/PIE794.py

@@ -38,3 +38,15 @@ class User:
     foo: bool = BooleanField()
     # ...
     bar = StringField()  # PIE794
+
+
+class Person:
+    name = "Foo"
+    name = name + " Bar"
+    name = "Bar"  # PIE794
+
+
+class Person:
+    name: str = "Foo"
+    name: str = name + " Bar"
+    name: str = "Bar"  # PIE794

crates/ruff_linter/src/rules/flake8_pie/rules/duplicate_class_field_definition.rs

@@ -3,6 +3,7 @@ use rustc_hash::FxHashSet;
 use ruff_diagnostics::Diagnostic;
 use ruff_diagnostics::{AlwaysFixableViolation, Fix};
 use ruff_macros::{derive_message_formats, violation};
+use ruff_python_ast::helpers::any_over_expr;
 use ruff_python_ast::{self as ast, Expr, Stmt};
 use ruff_text_size::Ranged;
 
@@ -55,14 +56,14 @@ pub(crate) fn duplicate_class_field_definition(checker: &mut Checker, body: &[St
         // Extract the property name from the assignment statement.
         let target = match stmt {
             Stmt::Assign(ast::StmtAssign { targets, .. }) => {
-                if let [Expr::Name(ast::ExprName { id, .. })] = targets.as_slice() {
+                if let [Expr::Name(id)] = targets.as_slice() {
                     id
                 } else {
                     continue;
                 }
             }
             Stmt::AnnAssign(ast::StmtAnnAssign { target, .. }) => {
-                if let Expr::Name(ast::ExprName { id, .. }) = target.as_ref() {
+                if let Expr::Name(id) = target.as_ref() {
                     id
                 } else {
                     continue;
@@ -71,10 +72,31 @@ pub(crate) fn duplicate_class_field_definition(checker: &mut Checker, body: &[St
             _ => continue,
         };
 
-        if !seen_targets.insert(target) {
+        // If this is an unrolled augmented assignment (e.g., `x = x + 1`), skip it.
+        match stmt {
+            Stmt::Assign(ast::StmtAssign { value, .. }) => {
+                if any_over_expr(value.as_ref(), &|expr| {
+                    expr.as_name_expr().is_some_and(|name| name.id == target.id)
+                }) {
+                    continue;
+                }
+            }
+            Stmt::AnnAssign(ast::StmtAnnAssign {
+                value: Some(value), ..
+            }) => {
+                if any_over_expr(value.as_ref(), &|expr| {
+                    expr.as_name_expr().is_some_and(|name| name.id == target.id)
+                }) {
+                    continue;
+                }
+            }
+            _ => continue,
+        }
+
+        if !seen_targets.insert(target.id.as_str()) {
             let mut diagnostic = Diagnostic::new(
                 DuplicateClassFieldDefinition {
-                    name: target.to_string(),
+                    name: target.id.to_string(),
                 },
                 stmt.range(),
             );

crates/ruff_linter/src/rules/flake8_pie/snapshots/ruff_linter__rules__flake8_pie__tests__PIE794_PIE794.py.snap

@@ -73,5 +73,41 @@ PIE794.py:40:5: PIE794 [*] Class field `bar` is defined multiple times
 38 38 |     foo: bool = BooleanField()
 39 39 |     # ...
 40    |-    bar = StringField()  # PIE794
+41 40 | 
+42 41 | 
+43 42 | class Person:
+
+PIE794.py:46:5: PIE794 [*] Class field `name` is defined multiple times
+   |
+44 |     name = "Foo"
+45 |     name = name + " Bar"
+46 |     name = "Bar"  # PIE794
+   |     ^^^^^^^^^^^^ PIE794
+   |
+   = help: Remove duplicate field definition for `name`
+
+ℹ Unsafe fix
+43 43 | class Person:
+44 44 |     name = "Foo"
+45 45 |     name = name + " Bar"
+46    |-    name = "Bar"  # PIE794
+47 46 | 
+48 47 | 
+49 48 | class Person:
+
+PIE794.py:52:5: PIE794 [*] Class field `name` is defined multiple times
+   |
+50 |     name: str = "Foo"
+51 |     name: str = name + " Bar"
+52 |     name: str = "Bar"  # PIE794
+   |     ^^^^^^^^^^^^^^^^^ PIE794
+   |
+   = help: Remove duplicate field definition for `name`
+
+ℹ Unsafe fix
+49 49 | class Person:
+50 50 |     name: str = "Foo"
+51 51 |     name: str = name + " Bar"
+52    |-    name: str = "Bar"  # PIE794