add coverage

scriptworker/test/test_cot_verify.py

@@ -1219,6 +1219,23 @@ async def test_verify_parent_task_definition_failed_diff(chain, mocker):
         )
 
 
+@pytest.mark.asyncio
+async def test_verify_parent_task_definition_failed_diff(chain, mocker):
+    link = cotverify.LinkOfTrust(chain.context, 'decision', "VQU9QMO4Teq7zr91FhBusg")
+    link.task = load_json_or_yaml(os.path.join(COTV2_DIR, "decision_hg-push.json"), is_path=True)
+    link.task['extra']['tasks_for'] = 'illegal'
+
+    mocker.patch.object(cotverify, 'load_json_or_yaml_from_url', new=cotv2_load_url)
+    mocker.patch.object(cotverify, 'load_json_or_yaml', new=cotv2_load)
+    mocker.patch.object(cotverify, 'get_pushlog_info', new=cotv2_pushlog)
+
+    chain.links = [link]
+    with pytest.raises(CoTError):
+        await cotverify.verify_parent_task_definition(
+            chain, link
+        )
+
+
 # verify_parent_task {{{1
 @pytest.mark.asyncio
 @pytest.mark.parametrize("defn_fn,min_cot_version,raises", ((