Robolectric：如何验证片段显示D​​ialogFragment

Question

我有以下例程，我正在尝试使用Robolectric进行测试：

/**
 * The add attachment button has been selected, present the picker.
 */
public void onAddAttachment() {
    AttachmentPickerDialog.create(this).show(getFragmentManager(), "attachment");
}

到目前为止，我的测试看起来像：

@Test
public void onAddAttachment() {
    // Bunch of setup stuff so APD can do it's thing and MessageFragment can do their things

    // Create and start the fragment
    MessageFragment fragment = new MessageFragment();
    fragment.setMessage(new MailMessage(RuntimeEnvironment.application, "http://some.random.com", 32));
    startFragment(fragment);

    // Call I'm actually trying to test
    fragment.onAddAttachment();

    // This verifies that my desired fragment is the top fragment
    List<Fragment> fragments = fragment.getFragmentManager().getFragments();
    AttachmentPickerDialog attachmentPickerDialog = (AttachmentPickerDialog) fragments.get(fragments.size() - 1);

    // And that it got initialized with the correct stuff, really an APD test
    // not an onAddAttachment test
    assertEquals(providers, attachmentPickerDialog.getOptions());

    // How to verify that the fragment dialog showing happened correctly?
    // This verifies that A dialog was created, but not necessarily that
    // it was a result of apd.show
    Dialog dialog = ShadowDialog.getLatestDialog();
    assertNotNull(dialog);
}

这一切似乎工作正常，我可以验证是否显示了正确的片段并且它已正确设置，但我正在努力尝试验证DialogFragment对话框是否显示。我是否需要麻烦，或者是否足以验证片段堆栈顶部是否有正确的DF？