Profile My skills Saved My plugins Edit profile Submit a skill

Python3 Tdd

Guides test-driven development for Python using a five-phase red-green-refactor cycle. Use when asked to write tests first, apply TDD, do test-first implementation, or follow red-green-refactor — designs typed interfaces and Protocol classes, writes failing pytest tests (RED), implements minimal passing code (GREEN), verifies with prek or ruff plus pytest-cov, and enforces a quality gate requiring all tests pass with no lint or type errors and coverage at or above 80 percent.

Jamie-BitFlight Updated
Coding & Dev Tools

File contents

TDD Workflow

Consult python3-core for standing defaults. Load python3-testing for detailed test patterns.

Input

Task: $ARGUMENTS

Phases

1. Design Interface

  • Define function signatures with full type annotations
  • Create Protocol classes for dependencies
  • Write docstrings before implementation
  • Load python3-typing when boundary types or models are involved

2. Write Failing Tests

  • Load python3-testing for fixture patterns and test structure
  • Tests must fail initially (RED)
  • AAA pattern; behavioral naming
  • Run uv run pytest -v — confirm failures

3. Implement to Pass

  • Minimal code to make tests pass (GREEN)
  • Run uv run pytest -v after each change
  • Refactor only while tests stay green

4. Verify

# Linting, formatting, and type checking
uv run prek run --files src/ tests/
# Fallback when no .pre-commit-config.yaml:
# uv run ruff check src/ tests/
# uv run ruff format --check src/ tests/

# Tests with coverage
uv run pytest --cov=src --cov-report=term-missing

5. Quality Gate

  • All tests pass
  • No lint errors
  • No type errors
  • Coverage ≥80%
  • Shebang validated on scripts

Jamie-BitFlight/claude_skills/tree/main/plugins/python-engineering/skills/python3-tdd commit 6838df58f2

Browse category

Frequently asked questions

npx skillmds@latest add jamie-bitflight/python3-tdd