CFNv2: Support the list parameter type (#12904)

simonrw · web-flow · commit c917f5048e48 · 2025-07-24T21:11:40.000+01:00
diff --git a/localstack-core/localstack/services/cloudformation/engine/v2/change_set_model_preproc.py b/localstack-core/localstack/services/cloudformation/engine/v2/change_set_model_preproc.py
@@ -933,6 +933,19 @@ def visit_node_parameter(self, node_parameter: NodeParameter) -> PreprocEntityDe
         before = dynamic_delta.before or default_delta.before
         after = dynamic_delta.after or default_delta.after
 
+        parameter_type = self.visit(node_parameter.type_)
+
+        def _resolve_parameter_type(value: str, type_: str) -> Any:
+            match type_:
+                case "List<String>":
+                    return [item.strip() for item in value.split(",")]
+            return value
+
+        if not is_nothing(before):
+            before = _resolve_parameter_type(before, parameter_type.before)
+        if not is_nothing(after):
+            after = _resolve_parameter_type(after, parameter_type.after)
+
         return PreprocEntityDelta(before=before, after=after)
 
     def visit_node_depends_on(self, node_depends_on: NodeDependsOn) -> PreprocEntityDelta:
diff --git a/tests/aws/services/cloudformation/v2/ported_from_v1/api/test_stacks.py b/tests/aws/services/cloudformation/v2/ported_from_v1/api/test_stacks.py
@@ -677,7 +677,6 @@ def test_events_resource_types(deploy_cfn_template, snapshot, aws_client):
     snapshot.match("resource_types", resource_types)
 
 
-@pytest.mark.skip(reason="CFNV2:Deletion")
 @markers.aws.validated
 def test_list_parameter_type(aws_client, deploy_cfn_template, cleanups):
     stack_name = f"test-stack-{short_uid()}"
