验证异步任务是否在robolectric 3上运行

Question

I have a method that starts couple of async tasks on background thread:

public void fetchSome() {
    new SomeTask1().execute();
    new SomeTask2().execute();
    new SomeTask3().execute();
}

How can I test that these three tasks are executed with Robolectric 3.0 .

Answer 1

Before I would warn you that AsyncTask are not good solution for performing background operations. Take a look to talks in internet what is so bad with AsyncTask .

As for me you're trying to test too many things. I would split it.

1. Test that your code is starting async tasks:

   • Write a Factory class which will instantiate async tasks for you
   • Mock factory in test and return mocks for tasks
   • Check that execute for task happened

2. Test that your tasks are doing right job:

   • Write test for every async task class
   • mock dependencies and check that tasks are interacting with outside world correctly

3. Test that your tasks update UI with result:

   • Introduce listeners
   • Mock them and pass to async tasks
   • Check that sync tasks calls them during final own lifecycle
   • Make UI implement listeners contract
   • Call in UI test listener methods
   • Check that it is updated correctly with results

Hope it helps!