android - How can I shadow the PackageManager with Robolectric

Question

My Android application has a simple method to fire off an intent to display a URL.

protected void launchBrowser(int id)
{
    Uri uri = Uri.parse( getString( id ) );
    Intent intent = new Intent( ACTION_VIEW, uri);

    PackageManager packageManager = getPackageManager();
    List<ResolveInfo> activities = packageManager.queryIntentActivities(intent, 0);
    if (activities.size() > 0)
    {
        startActivity(intent);
    }
    else
    {
        Toast.makeText(getApplicationContext(),
                       "ERROR - no application to display a web page",
                       Toast.LENGTH_SHORT).show();
    }
}

I'm using Robolectric for unit testing but I'm having trouble verifying this method. Specifically, getPackageManager() is always returning null. How I can shadow the PackageManager? I tried creating a ShadowPackageManager and calling bindShadowClass, but none of my code gets executed - getPackageManager() always returns null. I also tried to Shadow the Application context and return a concrete StubPackageManager, but got the same results. Maybe I've been searching/staring too long - is there a better way to unit test this method?

Answer 1

I'm using Robolectric 2.3 for this. As noted in other answers, getPackageManager() does not return null, but shadowApplication.setPackageManager no longer exists.

Since you can't mock PackageManager, you can't give it a list of Intents to resolve for. Fortunately, Robolectric's PackageManager subclass, RobolectricPackageManager, can let you add these intents without a mock:

RobolectricPackageManager rpm = (RobolectricPackageManager)Robolectric.application.getPackageManager();
rpm.addResolveInfoForIntent(new Intent(Settings.ACTION_APPLICATION_DEVELOPMENT_SETTINGS), new ResolveInfo());