How to test Event Listeners in Camunda?

Question

I have used Execution and Task Listener in my process. How to unit test them using Junit in Camunda.

Answer 1

You could use for example the Camunda Model API and write a unit test to test your Execution listener.

The unit test could look like the following:

  @Test
  public void testEndExecutionListenerIsCalledOnlyOnce() {

    BpmnModelInstance modelInstance = Bpmn.createExecutableProcess("process")
      .startEvent()
      .userTask()
      .camundaExecutionListenerClass(ExecutionListener.EVENTNAME_END, TestingExecutionListener.class.getName())
      .endEvent()
      .done();

    testHelper.deploy(modelInstance);

    // given
    ProcessInstance procInst = runtimeService.startProcessInstanceByKey("process");
    TaskQuery taskQuery = taskService.createTaskQuery().processInstanceId(procInst.getId());

    //when task is completed
    taskService.complete(taskQuery.singleResult().getId());

    // then end listener is called
    // assert something for example a variable is set or something else
  }

For more examples see how Camunda tests the Execution Listeners in ExecutionListenerTest.java.