From 60f18bd0ef7a0c469343b93a96414caba556076e Mon Sep 17 00:00:00 2001
From: epenet <6771947+epenet@users.noreply.github.com>
Date: Mon, 8 Jul 2024 13:43:41 +0000
Subject: [PATCH] [flake8-return] Exempt properties (RET501)

---
 .../test/fixtures/flake8_return/RET501.py     |  5 ++++
 .../src/checkers/ast/analyze/statement.rs     |  7 ++++-
 .../src/rules/flake8_return/rules/function.rs | 30 ++++++++++++++++---
 3 files changed, 37 insertions(+), 5 deletions(-)

diff --git a/crates/ruff_linter/resources/test/fixtures/flake8_return/RET501.py b/crates/ruff_linter/resources/test/fixtures/flake8_return/RET501.py
index 9bde6810cd7a1..57e814d70d6bd 100644
--- a/crates/ruff_linter/resources/test/fixtures/flake8_return/RET501.py
+++ b/crates/ruff_linter/resources/test/fixtures/flake8_return/RET501.py
@@ -12,3 +12,8 @@ def get(self, key: str) -> str | None:
     def get(self, key: str) -> None:
         print(f"{key} not found")
         return None
+
+    @property
+    def prop(self) -> None:
+        print("Property not found")
+        return None
diff --git a/crates/ruff_linter/src/checkers/ast/analyze/statement.rs b/crates/ruff_linter/src/checkers/ast/analyze/statement.rs
index e92fee7e8d45e..433653c92ecba 100644
--- a/crates/ruff_linter/src/checkers/ast/analyze/statement.rs
+++ b/crates/ruff_linter/src/checkers/ast/analyze/statement.rs
@@ -223,7 +223,12 @@ pub(crate) fn statement(stmt: &Stmt, checker: &mut Checker) {
                 Rule::SuperfluousElseContinue,
                 Rule::SuperfluousElseBreak,
             ]) {
-                flake8_return::rules::function(checker, body, returns.as_ref().map(AsRef::as_ref));
+                flake8_return::rules::function(
+                    checker,
+                    body,
+                    decorator_list,
+                    returns.as_ref().map(AsRef::as_ref),
+                );
             }
             if checker.enabled(Rule::UselessReturn) {
                 pylint::rules::useless_return(
diff --git a/crates/ruff_linter/src/rules/flake8_return/rules/function.rs b/crates/ruff_linter/src/rules/flake8_return/rules/function.rs
index 124abdfee953e..a1f0f400fe30e 100644
--- a/crates/ruff_linter/src/rules/flake8_return/rules/function.rs
+++ b/crates/ruff_linter/src/rules/flake8_return/rules/function.rs
@@ -9,7 +9,7 @@ use ruff_python_ast::helpers::{is_const_false, is_const_true};
 use ruff_python_ast::stmt_if::elif_else_range;
 use ruff_python_ast::visitor::Visitor;
 use ruff_python_ast::whitespace::indentation;
-use ruff_python_ast::{self as ast, ElifElseClause, Expr, Stmt};
+use ruff_python_ast::{self as ast, Decorator, ElifElseClause, Expr, Stmt};
 use ruff_python_codegen::Stylist;
 use ruff_python_index::Indexer;
 use ruff_python_semantic::SemanticModel;
@@ -364,7 +364,16 @@ impl Violation for SuperfluousElseBreak {
 }
 
 /// RET501
-fn unnecessary_return_none(checker: &mut Checker, stack: &Stack) {
+fn unnecessary_return_none(checker: &mut Checker, decorator_list: &[Decorator], stack: &Stack) {
+    // Skip properties.
+    let semantic = checker.semantic();
+    if decorator_list
+        .iter()
+        .any(|decorator| semantic.match_builtin_expr(&decorator.expression, "property"))
+    {
+        return;
+    }
+
     for stmt in &stack.returns {
         let Some(expr) = stmt.value.as_deref() else {
             continue;
@@ -731,7 +740,12 @@ fn superfluous_elif_else(checker: &mut Checker, stack: &Stack) {
 }
 
 /// Run all checks from the `flake8-return` plugin.
-pub(crate) fn function(checker: &mut Checker, body: &[Stmt], returns: Option<&Expr>) {
+pub(crate) fn function(
+    checker: &mut Checker,
+    body: &[Stmt],
+    decorator_list: &[Decorator],
+    returns: Option<&Expr>,
+) {
     // Find the last statement in the function.
     let Some(last_stmt) = body.last() else {
         // Skip empty functions.
@@ -785,9 +799,17 @@ pub(crate) fn function(checker: &mut Checker, body: &[Stmt], returns: Option<&Ex
         }
     } else {
         if checker.enabled(Rule::UnnecessaryReturnNone) {
+            // Skip properties.
+            let semantic = checker.semantic();
+            if decorator_list
+                .iter()
+                .any(|decorator| semantic.match_builtin_expr(&decorator.expression, "property"))
+            {
+                return;
+            }
             // Skip functions that have a return annotation that is not `None`.
             if returns.map_or(true, Expr::is_none_literal_expr) {
-                unnecessary_return_none(checker, &stack);
+                unnecessary_return_none(checker, decorator_list, &stack);
             }
         }
     }