如何使用Robolectric测试PreferenceFragment

Question

Im trying to test my PreferenceActivity that uses two different PreferenceFragments. I start the Activity with an Intent like:

public static Intent getActivityIntent(Context context, Mode mode){
    Intent intent = new Intent(context, MyPreferencesActivity.class);
    intent.putExtra( PreferenceActivity.EXTRA_SHOW_FRAGMENT, getMainFragmentName(mode));
    intent.putExtra( PreferenceActivity.EXTRA_SHOW_FRAGMENT_ARGUMENTS, getMainFragmentArguments(mode));
    intent.putExtra( PreferenceActivity.EXTRA_NO_HEADERS, true );
    return intent;
}

where getMainFragmentName and getMainFragmentArguments returns different fragments and arguments depending on the mode.

Now, my problem is that when I start the activity with robolectric like:

Robolectric.buildActivity(MyPreferencesActivity.class)
            .withIntent(MyPreferencesActivity.getActivityIntent(Robolectric.application,
                    MyPreferencesActivity.Mode.FULL))
            .attach()
            .create()
            .postCreate(null)
            .start()
            .resume()
            .get();

I don't know how to make sure that the correct fragment has been create. When I debug the code, it looks like no fragment were created. Shouldn't the code above be enough to create the fragment?

I have tried to use a shadow of the PreferenceActivity and tested :

assertNotNull(shadowPreferenceActivity.getPreferencesScreen());

but that just fails.

The code works perfectly in my application and the correct fragment is created and added.

Answer 1

I don't know about the preferences in particular, but I have done general fragment testing. I think you need to add a call to ActivityController.visible() when building your activity in order for it to create the fragments. I've also found you need to be careful about the ordering of the call to visible after create. In my tests I do create then visible then start, but see what works for you. eg:

activity = Robolectric.buildActivity(YourActivity.class).create(bundle).visible().start().resume().get();

Also note that getPreferencesScreen has been deprecated. So you should use one of the standard android methods findFragmentBy[Id|Tag] to get hold of the fragment. eg:

Fragment f = activity.getSupportFragmentManager().findFragmentById(R.id.your_id);