SONARPY-1007 S5644 (ItemOperationsTypeCheck) should not raise when accessing type with generics (#1120)

Author: andrea-guarino-sonarsource

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

@@ -33,6 +33,7 @@
 import org.sonar.plugins.python.api.tree.Tree;
 import org.sonar.python.tree.TreeUtils;
 
+import static org.sonar.python.tree.TreeUtils.getSymbolFromTree;
 import static org.sonar.python.tree.TreeUtils.nameFromExpression;
 
 public abstract class ItemOperationsType extends PythonSubscriptionCheck {
@@ -47,7 +48,7 @@ public void initialize(Context context) {
 
   private void checkSubscription(SubscriptionContext ctx) {
     SubscriptionExpression subscriptionExpression = (SubscriptionExpression) ctx.syntaxNode();
-    if (isWithinTypeAnnotation(subscriptionExpression)) {
+    if (isWithinTypeAnnotation(subscriptionExpression) || isTypeSubscription(subscriptionExpression.object())) {
       return;
     }
     Map<LocationInFile, String> secondaries = new HashMap<>();
@@ -69,6 +70,11 @@ private void checkSubscription(SubscriptionContext ctx) {
     }
   }
 
+  // Avoid FPs on alias with type generics like `alias = type[Foo]`
+  private static boolean isTypeSubscription(Expression subscriptionObject) {
+    return getSymbolFromTree(subscriptionObject).filter(symbol -> "type".equals(symbol.fullyQualifiedName())).isPresent();
+  }
+
   private static boolean isWithinTypeAnnotation(SubscriptionExpression subscriptionExpression) {
     return TreeUtils.firstAncestor(subscriptionExpression,
       t -> t.is(Tree.Kind.PARAMETER_TYPE_ANNOTATION, Tree.Kind.RETURN_TYPE_ANNOTATION, Tree.Kind.VARIABLE_TYPE_ANNOTATION)) != null;

python-checks/src/test/resources/checks/itemOperationsTypeCheck/itemOperations_getitem.py

@@ -189,3 +189,6 @@ def python3_9():
   from asyncio import Future
   class A(Future[TSource]): ...
 
+
+def python3_10():
+  type_alias = type[Exception]