Add one more test for YAQL error message format

Change-Id: I69d7551d380eb4feed957b8815624529ebcdeca9
Closes-Bug: #1630473

mistral/tests/unit/engine/test_error_handling.py

@@ -363,7 +363,7 @@ class ErrorHandlingEngineTest(base.EngineTestCase):
             state=states.SUCCESS
         )
 
-    def test_error_message_format(self):
+    def test_error_message_format_key_error(self):
         wf_text = """
         version: '2.0'
 
@@ -390,3 +390,31 @@ class ErrorHandlingEngineTest(base.EngineTestCase):
 
         self.assertIsNotNone(state_info)
         self.assertTrue(state_info.find('error') < state_info.find('data'))
+
+    def test_error_message_format_unknown_function(self):
+        wf_text = """
+        version: '2.0'
+
+        wf:
+          tasks:
+            task1:
+              action: std.noop
+              publish:
+                my_var: <% invalid_yaql_function() %>
+        """
+
+        wf_service.create_workflows(wf_text)
+
+        wf_ex = self.engine.start_workflow('wf', {})
+
+        self.await_workflow_error(wf_ex.id)
+
+        with db_api.transaction():
+            wf_ex = db_api.get_workflow_execution(wf_ex.id)
+
+            task_ex = wf_ex.task_executions[0]
+
+        state_info = task_ex.state_info
+
+        self.assertIsNotNone(state_info)
+        self.assertTrue(state_info.find('error') < state_info.find('data'))