SONARPY-3030 Fix S6546 false positive for union types inside typing.Annotated (#1002)

Co-authored-by: Vibe Bot <vibe-bot@sonarsource.com>
GitOrigin-RevId: cbb9c9f4c9648b2e541e997c467235569a1f7301

Author: 2 people

python-checks/src/main/java/org/sonar/python/checks/UnionTypeExpressionCheck.java

@@ -16,20 +16,23 @@
  */
 package org.sonar.python.checks;
 
+import java.util.function.Predicate;
 import org.sonar.check.Rule;
 import org.sonar.plugins.python.api.PythonSubscriptionCheck;
 import org.sonar.plugins.python.api.PythonVersionUtils;
 import org.sonar.plugins.python.api.SubscriptionContext;
 import org.sonar.plugins.python.api.tree.Expression;
 import org.sonar.plugins.python.api.tree.Tree;
 import org.sonar.plugins.python.api.tree.TypeAnnotation;
-import org.sonar.plugins.python.api.types.InferredType;
-import org.sonar.python.types.InferredTypes;
+import org.sonar.plugins.python.api.types.v2.matchers.TypeMatcher;
+import org.sonar.plugins.python.api.types.v2.matchers.TypeMatchers;
+import org.sonar.python.tree.TreeUtils;
 
 @Rule(key = "S6546")
 public class UnionTypeExpressionCheck extends PythonSubscriptionCheck {
 
   private static final String MESSAGE = "Use a union type expression for this type hint.";
+  private static final TypeMatcher TYPING_UNION_MATCHER = TypeMatchers.isType("typing.Union");
 
   @Override
   public void initialize(Context context) {
@@ -45,13 +48,9 @@ private static void checkTypeAnnotation(SubscriptionContext ctx) {
 
     TypeAnnotation typeAnnotation = (TypeAnnotation) ctx.syntaxNode();
     Expression expression = typeAnnotation.expression();
-    if (expression.is(Tree.Kind.BITWISE_OR)) {
-      return;
-    }
 
-    InferredType type = InferredTypes.fromTypeAnnotation(typeAnnotation);
-    String fqn = InferredTypes.fullyQualifiedTypeName(type);
-    if ("typing.Union".equals(fqn)) {
+    Predicate<Tree> isUnionName = n -> n.is(Tree.Kind.NAME) && TYPING_UNION_MATCHER.isTrueFor((Expression) n, ctx);
+    if (isUnionName.test(expression) || TreeUtils.hasDescendant(expression, isUnionName)) {
       ctx.addIssue(expression, MESSAGE);
     }
   }

python-checks/src/test/resources/checks/unionTypeExpression.py

@@ -1,4 +1,4 @@
-from typing import Union
+from typing import Annotated, Union
 from typing import Union as u
 import typing
 import typing as t
@@ -40,8 +40,7 @@ def instance_method() -> Union[int, str]: # Noncompliant
         pass
 
 
-# There is no clear recommendation on this case, so we will just not handle them for the time being.
-def union_in_generic_type() -> list[Union[int, str]]: # FN
+def union_in_generic_type() -> list[Union[int, str]]: # Noncompliant
     pass
 
 def ok(param: int | str) -> int | str:
@@ -66,3 +65,13 @@ def unknown_return_type() -> unknown:
 
 def unknown_return_type_subscript() -> unknown[int, str]:
     pass
+
+variable: Annotated[int | str, "metadata"]
+
+top_level: Annotated[float | bytes, "info"]
+
+def annotated_param(value: Annotated[int | str, "description"]) -> None:
+    pass
+
+def annotated_return() -> Annotated[int | str, "result"]:
+    return 42