testing-workflow

Unit tests with pytest start by creating a tests/ directory and writing test functions prefixed with test_. Use pytest fixtures for reusable setup, mocking to isolate dependencies, and parametrization to test multiple inputs. Run pytest from your project root to execute all tests and view results.

Organize tests by mirroring your source code structure in a tests/ directory. Separate unit, integration, and async tests into distinct modules. Use pytest fixtures in conftest.py for shared setup across test files. This structure scales and makes maintenance straightforward.

Fixtures are reusable setup functions decorated with @pytest.fixture that dependencies inject into test functions. Use mocking to replace external calls with controlled substitutes. Define fixtures in conftest.py for project-wide reuse, keeping tests isolated and deterministic.

Yes, pytest supports async tests through plugins like pytest-asyncio. Mark async test functions with @pytest.mark.asyncio and define async fixtures with @pytest.fixture. This lets you test coroutines and async workflows alongside synchronous tests.

Use pytest with coverage.py to measure which code paths your tests exercise. Run pytest --cov to generate coverage reports identifying untested lines. Set coverage targets and iterate to close gaps, improving reliability and catching edge cases.

Fixtures provide reusable setup and teardown; mocks replace real dependencies with controlled substitutes. Use fixtures for common test state and mocks to isolate the code under test from external systems, databases, or APIs.