Basic Test Structure
import pytest
class TestUserService: def test_create_user_success(self): user = create_user(name="John", email="john@test.com") assert user.name == "John" assert user.email == "john@test.com"
def test_create_user_invalid_email_fails(self):
with pytest.raises(ValueError, match="Invalid email"):
create_user(name="John", email="invalid")
Fixtures
import pytest
@pytest.fixture def user(): """Create a test user.""" return User(name="Test User", email="test@example.com")
@pytest.fixture def authenticated_client(client, user): """Client with authenticated user.""" client.force_login(user) return client
Fixture with teardown
@pytest.fixture def temp_file(): path = Path("/tmp/test_file.txt") path.write_text("test content") yield path # Test runs here path.unlink() # Cleanup after test
Fixture scopes
@pytest.fixture(scope="module") # Once per module @pytest.fixture(scope="class") # Once per class @pytest.fixture(scope="session") # Once per test session
conftest.py
tests/conftest.py - Shared fixtures
import pytest
@pytest.fixture def db_session(): session = create_session() yield session session.rollback()
@pytest.fixture def api_client(): return TestClient(app)
Mocking
from unittest.mock import patch, MagicMock
class TestPaymentService: def test_process_payment_success(self): with patch("services.payment.stripe_client") as mock_stripe: mock_stripe.charge.return_value = {"id": "ch_123", "status": "succeeded"}
result = process_payment(amount=100)
assert result["status"] == "succeeded"
mock_stripe.charge.assert_called_once_with(amount=100)
def test_process_payment_failure(self):
with patch("services.payment.stripe_client") as mock_stripe:
mock_stripe.charge.side_effect = PaymentError("Card declined")
with pytest.raises(PaymentError):
process_payment(amount=100)
MagicMock for complex objects
def test_with_mock_object(): mock_user = MagicMock() mock_user.id = "user-123" mock_user.name = "Test User" mock_user.is_active = True
result = get_user_info(mock_user)
assert result["name"] == "Test User"
Parametrize
@pytest.mark.parametrize("input,expected", [ ("hello", "HELLO"), ("world", "WORLD"), ("pytest", "PYTEST"), ]) def test_uppercase(input, expected): assert input.upper() == expected
@pytest.mark.parametrize("email,is_valid", [ ("user@example.com", True), ("invalid-email", False), ("", False), ("user@.com", False), ]) def test_email_validation(email, is_valid): assert validate_email(email) == is_valid
Markers
pytest.ini or pyproject.toml
[tool.pytest.ini_options] markers = [ "slow: marks tests as slow", "integration: marks integration tests", ]
Usage
@pytest.mark.slow def test_large_data_processing(): ...
@pytest.mark.integration def test_database_connection(): ...
@pytest.mark.skip(reason="Not implemented yet") def test_future_feature(): ...
@pytest.mark.skipif(sys.platform == "win32", reason="Unix only") def test_unix_specific(): ...
Run specific markers
pytest -m "not slow"
pytest -m "integration"
Async Tests
import pytest
@pytest.mark.asyncio async def test_async_function(): result = await async_fetch_data() assert result is not None
Commands
pytest # Run all tests pytest -v # Verbose output pytest -x # Stop on first failure pytest -k "test_user" # Filter by name pytest -m "not slow" # Filter by marker pytest --cov=src # With coverage pytest -n auto # Parallel (pytest-xdist) pytest --tb=short # Short traceback
References
For general pytest documentation, see:
- Official Docs: https://docs.pytest.org/en/stable/
For Prowler SDK testing with provider-specific patterns (moto, MagicMock), see:
- Documentation: references/prowler-testing.md