Python Testing Hub

Testing standards for pytest configuration, fixture management, and TDD implementation.

Table of Contents

1. Quick Start
2. When to Use
3. Modules

Quick Start

1. Dependencies:

   pip install pytest pytest-cov pytest-asyncio pytest-mock

2. Configuration: Add the following to

   pyproject.toml

   :

   [tool.pytest.ini_options]
   testpaths = ["tests"]
   addopts = "--cov=src"
   

3. Verification: Run

   pytest

   to confirm discovery of files matching

   test_*.py

   .

When To Use

• Constructing unit and integration tests for Python 3.9+ projects.
• Isolating external dependencies using

  pytest-mock

  or custom monkeypatching.
• Validating asynchronous logic with

  pytest-asyncio

  markers and event loop management.
• Configuring project-wide coverage thresholds and reporting.

When NOT To Use

• Evaluating test quality - use pensive:test-review instead
• Infrastructure test config - use leyline:pytest-config

Modules

This skill uses modular loading to manage the system prompt budget.

Core Implementation

• See

  modules/unit-testing.md

  - AAA (Arrange-Act-Assert) pattern, basic test structure, and exception validation.
• See

  modules/fixtures-and-mocking.md

  - Request-scoped fixtures, parameterization, and boundary mocking.
• See

  modules/async-testing.md

  - Coroutine testing, async fixtures, and concurrency validation.

Infrastructure & Workflow

• See

  modules/test-infrastructure.md

  - Directory standards,

  conftest.py

  management, and coverage tools.
• See

  modules/testing-workflows.md

  - Local execution patterns and GitHub Actions integration.

Standards

• See

  modules/test-quality.md

  - Identification of common anti-patterns like broad exception catching or shared state between tests.

Exit Criteria

• Tests implement the AAA pattern.
• Coverage reaches the 80% project minimum.
• Individual tests are independent and do not rely on execution order.
• Fixtures are scoped appropriately (function, class, or session) to prevent side effects.
• Mocking is restricted to external system boundaries.

Troubleshooting

• Test Discovery: Verify filenames match the

  test_*.py

  pattern. Use

  pytest --collect-only

  to debug discovery paths.
• Import Errors: Ensure the local source directory is in the path, typically by installing in editable mode with

  pip install -e .

  .
• Async Failures: Confirm that

  pytest-asyncio

  is installed and that async tests use the

  @pytest.mark.asyncio

  decorator or corresponding auto-mode configuration.