tests/test_downloader.py

from unittest.mock import AsyncMock

import respx
from httpx import Response

from app.services.downloader import Downloader
from app.services.validator import MediaValidator


@respx.mock
async def test_url_download_streams_to_disk(settings, tmp_path) -> None:
    url = "https://media.example.test/sample.mp3"
    respx.get(url).mock(
        return_value=Response(200, content=b"ID3data", headers={"content-type": "audio/mpeg"})
    )
    downloader = Downloader(settings, MediaValidator(settings))
    downloader.validate_url = AsyncMock()  # type: ignore[method-assign]
    path, mime_type = await downloader.download(url, tmp_path)
    assert path.read_bytes() == b"ID3data"
    assert mime_type == "audio/mpeg"