Testing if a recently launched activity actually has started

I have looked into a few similar questions on SO, but have not yeet managed to successfully test this.

Android - testing if another activity has started

I tried this one, but for me, origactivity turns out to be null, so I used .baseIntent.getComponent() instead to identify the started activity(I suppose this should give me the same result?)

My JUnit test code:

public class MainMenuTest extends
        ActivityInstrumentationTestCase2<MainMenuActivity> {

    public MainMenuTest() {
        super("package.name", MainMenuActivity.class);
    }

    private MainMenuActivity mActivity;
    private ActivityManager am;

    public void setUp() throws Exception {
        super.setUp();
        mActivity = this.getActivity();
        am = (ActivityManager) mActivity.getSystemService(Service.ACTIVITY_SERVICE);
        Intent i = new Intent(mActivity, GameActivity.class).setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
        mActivity.startActivity(i);
    }

    public void testNewGameButton() {
        final ActivityManager am2 = am;

        mActivity.runOnUiThread(new Runnable() {
            public void run() {                 
                List<ActivityManager.RecentTaskInfo> processes = am2.getRecentTasks(2, ActivityManager.RECENT_WITH_EXCLUDED);
                ActivityManager.RecentTaskInfo recentTask = processes.get(0);
                assertEquals(recentTask.baseIntent.get开发者_Go百科Component().getClassName(), GameActivity.class.getName());
            }
        });
    }
}

Unfortunately, this causes the assertEquals(recentTask.baseIntent.getComponent().getClassName(), assertion to fail.

Why is this, and is there a better way to test this?

---

The assert fails because ActivityManager.getRecentTasks(...) returns activities that caused new task to be created, and in your case that is MainMenuActivity, not GameActivity. You can use Instrumentation.ActivityMonitor though, like this:

public class MainMenuTest extends
        ActivityInstrumentationTestCase2<MainMenuActivity> {

    public MainMenuTest() {
        super("package.name", MainMenuActivity.class);
    }

    private MainMenuActivity mActivity;
    private ActivityMonitor mGameActivityMonitor;

    public void setUp() throws Exception {
        super.setUp();
        mActivity = this.getActivity();
        Intent i  = new Intent(mActivity,
                GameActivity.class).setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);

        // Add a monitor before we start the activity
        mGameActivityMonitor = 
                new ActivityMonitor(GameActivity.class.getName(), null, false);
        getInstrumentation().addMonitor(mGameActivityMonitor);

        mActivity.startActivity(i);
    }

    public void testNewGameButton() {
        // Use the monitor to ensure the activity was started
        Activity activity = mGameActivityMonitor.waitForActivityWithTimeout(5 * 1000);
        assertNotNull("Activity was not started", activity);
    }
}