Testing that button starts an Activity with Robolectric

Question

Hi I have the following code:

@RunWith(Test9Runner.class)
public class MainActivityTest 
{
    private MainActivity activity;
    private Button pressMeButton;

    @Before
    public void setUp() throws Exception 
    {
        activity = new MainActivity();
        activity.onCreate(null);
        pressMeButton = (Button) activity.findViewById(R.id.button1);
    }

    @Test
    public void shouldUpdateResultsWhenButtonIsClicked() throws Exception 
    {
        pressMeButton.performClick();
        ShadowActivity shadowActivity = shadowOf(activity);
        Intent intent = shadowActivity.getResultIntent();
        System.out.print(intent.toString());
    }
}

But I have no idea how to test that pressing pressMeButton started a new Activity. Actually it does, but how to write the correct Robolectric unit test for this fact?

Answer 1

In Robolectric 2.1.1 you can verify if Intent starting new Activity was emitted in following way.

@RunWith(RobolectricTestRunner.class)
public class MyTest {
  private ShadowActivity shadowActivity;
  private MyActivity activity;

  @Before
  public void setup() {
    activity = new MyActivity();
    shadowActivity = Robolectric.shadowOf(activity);        
  }

  @Test
  public shouldStartNewActivityWhenSomething() {
    //Perform activity startup
    //Do some action which starts second activity, for example View::performClick()
    //...
    //Check Intent
    Intent intent = shadowActivity.peekNextStartedActivityForResult().intent;
    assertThat(intent.getStringExtra(MySecondActivity.EXTRA_MESSAGE)).isEqualTo("blebleble");
    assertThat(intent.getComponent()).isEqualTo(new ComponentName(activity, MySecondActivity.class));
  }
}

This is similar to what I am doing. Please note that creating Activity by calling new Activity() will make Robolectric print warnings about creating activity improperly, this probably can be done better...