# Run all tests
cd backend && uv run pytest -v

# Run specific test file
uv run pytest tests/downloads/test_prowlarr_api.py -v

# Run specific test class
uv run pytest tests/downloads/test_qbittorrent_client.py::TestAddTorrent -v

# Run with output
uv run pytest -v -s

from unittest.mock import Mock, patch

@pytest.fixture
def mock_client():
    """Create client with mocked external dependency"""
    with patch('app.downloads.clients.qbittorrent.QBClient') as mock:
        mock_instance = Mock()
        mock.return_value = mock_instance
        mock_instance.app.version = "v4.6.0"
        
        client = QBittorrentClient(host="localhost", port=8080, ...)
        yield client

def test_successful_connection(self, mock_client):
    result = mock_client.test_connection()
    assert result is True

@pytest.fixture(scope="function")
def db_session():
    """Fresh database session per test"""
    Base.metadata.create_all(bind=engine)
    session = SessionLocal()
    try:
        yield session
    finally:
        session.close()
        Base.metadata.drop_all(bind=engine)

def test_create_task(self, db_session, sample_book):
    task = DownloadTask(book_id=sample_book.id, format="ebook", ...)
    db_session.add(task)
    db_session.commit()
    assert task.id is not None

backend/tests/
├── downloads/
│   ├── __init__.py
│   ├── test_models.py         # Integration: database models
│   ├── test_prowlarr_api.py   # Unit: Prowlarr client
│   ├── test_qbittorrent_client.py  # Unit: qBittorrent
│   └── test_nzbget_client.py  # Unit: NZBGet
└── conftest.py                # Shared fixtures (create if needed)