import pytest

@pytest.mark.xfail
def test_missing_file(audiomgr):
    sound = audiomgr.get_sound('/not/a/valid/file.ogg')
    assert sound is None

import pytest

def test_missing_file(audiomgr):
    sound = audiomgr.get_sound('/not/a/valid/file.ogg')
    assert str(sound).startswith('NullAudioSound')

Update audio test to recognize missing sounds as NullAudioSound
tests: Update audio test to recognize missing sounds as NullAudioSound
