pytest

Overview

pytest collects functions named test_* in files named test_*.py (or *_test.py), runs them, and rewrites plain assert statements so a failure shows both sides of the comparison. Fixtures provide setup and teardown, parametrize runs one test over many inputs, and plugins add async support, coverage, mocking and parallel runs. This skill targets pytest 9.x (checked against 9.1) with pytest-asyncio 1.x.

Instructions

Step 1: Install and configure

python -m venv .venv && source .venv/bin/activate
pip install pytest pytest-asyncio pytest-cov pytest-mock pytest-xdist

Put configuration in pyproject.toml ([tool.pytest.ini_options]) or, since pytest 9, in a native pytest.toml: