testing

name	testing
description	Use this skill when writing or modifying Python test files. Enforces pytest as the framework, src-mirroring file paths, test_-prefixed function names, fixtures for shared setup, parametrize for similar cases, and specific-value assertions over truthiness.

paths:

• "tests/**/*py"
• "*/test_py"

Testing Standards

Trigger

When writing or modifying test files.

Instructions

• Framework: pytest (never use unittest)
• Test file location: mirror source path src/utils/format.py→ tests/utils/test_format.py
• Naming: test functions start with test_ followed by descriptive name: test_validate_email_rejects_missing_domain
• Each function gets minimum 3 tests:

1. Happy path with typical input
2. Error case (None, empty, invalid type)
3. Edge case (boundary values, unicode, large inputs)

• Use pytest fixtures for shared setup
• Use parametrize for 3+ similar test cases
• Assert on specific values, not truthiness
• Bad: assert result

Good: assert result == 'validated'

Constraints

• Do not import from unittest
• Do not use mock patch unless the dependency is external (API, DB)
• Do not test private functions (prefix _) directly