tests/test_sting.py

"""The synthesized audio returns valid, non-trivial WAV bytes."""
import io
import wave

from sting import (chime_wav_bytes, flatline_wav_bytes, heartbeat_wav_bytes,
                   menu_loop_wav_bytes, sigh_wav_bytes, sting_wav_bytes,
                   type_tick_wav_bytes)


def _frames(b: bytes) -> int:
    with wave.open(io.BytesIO(b), "rb") as w:
        assert w.getnchannels() == 1
        assert w.getsampwidth() == 2
        return w.getnframes()


def test_heartbeat_is_a_whole_number_of_beats_for_seamless_loop():
    # 2 beats at 0.85 s => 1.7 s of audio at 22050 Hz
    frames = _frames(heartbeat_wav_bytes())
    assert frames == int(22050 * 1.7)


def test_sigh_is_a_few_seconds_of_audio():
    assert _frames(sigh_wav_bytes()) == int(22050 * 2.6)


def test_flatline_is_four_seconds():
    assert _frames(flatline_wav_bytes()) == int(22050 * 4.0)


def test_existing_sounds_still_synthesize():
    assert len(sting_wav_bytes()) > 1000
    assert len(chime_wav_bytes(0)) > 500


def test_menu_loop_is_valid_wav():
    b = menu_loop_wav_bytes()
    assert len(b) > 2000
    assert _frames(b) > int(22050 * 7)


def test_type_tick_is_a_short_valid_wav():
    b = type_tick_wav_bytes()
    assert len(b) > 400              # real audio, not empty
    assert _frames(b) < int(22050 * 0.2)   # a short tick, well under 0.2s