public virtual void testQueryByInvalidUserOperationId() { startProcessInstance(PROCESS_KEY); string taskId = taskService.createTaskQuery().singleResult().Id; // when taskService.resolveTask(taskId, Variables); //then HistoricDetailQuery query = historyService.createHistoricDetailQuery().userOperationId("invalid"); assertEquals(0, query.list().size()); assertEquals(0, query.count()); try { query.userOperationId(null); fail("It was possible to set a null value as userOperationId."); } catch (ProcessEngineException) { } }