AudioPlayerViewModel extends ViewModel implements MediaPlayer.OnCompletionListener { public void stop() { if (currentlyPlaying.getValue() != null) { getMediaPlayer().stop(); } cleanUpAfterClip(); } AudioPlayerViewModel(MediaPlayerFactory mediaPlayerFactory, Scheduler scheduler); void play(Clip clip); void playInOrder(List<Clip> clips); void stop(); void pause(); LiveData<Boolean> isPlaying(@NonNull String clipID); LiveData<Integer> getPosition(String clipID); void setPosition(String clipID, Integer newPosition); void background(); @Override void onCompletion(MediaPlayer mediaPlayer); LiveData<Exception> getError(); void dismissError();  }
@Test public void stop_beforePlay_doesntCallStopOnMediaPlayer() { viewModel.stop(); verify(mediaPlayer, never()).stop(); }