tests/test_lyrics.py

from __future__ import annotations

import numpy as np
import pytest

from openmusic_analysis.analyzers.lyrics import BGEM3LyricsAnalyzer, LyricsPreprocessor
from openmusic_analysis.errors import AnalysisError
from openmusic_analysis.settings import LyricsConfig

from .conftest import FakeTextEncoder


def analyzer(max_tokens: int = 12) -> BGEM3LyricsAnalyzer:
    return BGEM3LyricsAnalyzer(
        FakeTextEncoder(),
        LyricsPreprocessor(),
        LyricsConfig(max_chunk_tokens=max_tokens, batch_size=4),
    )


@pytest.mark.asyncio
@pytest.mark.parametrize(
    "lyrics",
    [
        "[Verse]\nHello, world!\nI remember you.\n\n[Chorus]\nCome home, come home.",
        "[Куплет 1]\nЯ помню этот день.\n\n[Припев]\nВернись, вернись ко мне!",
    ],
)
async def test_english_and_russian_are_finite_and_normalized(lyrics):
    result = await analyzer().analyze(lyrics)
    vector = np.asarray(result.embedding)
    assert result.dimension == 6
    assert np.isfinite(vector).all()
    assert np.linalg.norm(vector) == pytest.approx(1.0, abs=1e-6)


def test_preprocessor_preserves_multiline_sections_punctuation_and_repeated_chorus():
    lyrics = "[ar:metadata]\r\n[Verse]\r\nHello, world!\r\n\r\n[Chorus]\r\nAgain!\r\n[Chorus]\r\nAgain!"
    prepared = LyricsPreprocessor().prepare(lyrics)
    assert "[ar:metadata]" not in prepared.normalized_text
    assert "Hello, world!" in prepared.normalized_text
    assert [section.label.lower() for section in prepared.sections] == [
        "verse",
        "chorus",
        "chorus",
    ]
    assert [section.text for section in prepared.sections].count("Again!") == 2


@pytest.mark.asyncio
async def test_long_lyrics_use_token_chunks_and_deterministic_aggregation():
    lyrics = "[Verse]\n" + " ".join(f"word{index}" for index in range(80))
    first = await analyzer(max_tokens=10).analyze(lyrics)
    second = await analyzer(max_tokens=10).analyze(lyrics)
    assert first.analysis["chunk_count"] > 1
    assert max(first.analysis["chunk_token_counts"]) <= 10
    assert first.embedding == pytest.approx(second.embedding, abs=1e-7)


@pytest.mark.asyncio
async def test_empty_lyrics_are_rejected():
    with pytest.raises(AnalysisError) as raised:
        await analyzer().analyze(" \n\t ")
    assert raised.value.code == "INVALID_LYRICS"