# strict-tdd

> TDD Cycle

- Skill: `a5c-ai/strict-tdd` (Agent Skill, multi-file: 2 files)
- Install (CLI): `npx skillmds add a5c-ai/strict-tdd`
- Raw SKILL.md: https://api.skillmd.com/api/skills/a5c-ai/strict-tdd/raw
- Safety review: pending (external: skillspector PASS)
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Coding & Dev Tools
- Author: a5c-ai (https://skillmd.com/u/a5c-ai)
- Updated: 2026-08-19
- Page: https://skillmd.com/skills/a5c-ai/strict-tdd

---


## TDD Cycle

### RED Phase
1. Write a test that captures exactly one acceptance criterion
2. Run the test -- it MUST fail
3. Verify it fails for the RIGHT reason (not a syntax error)
4. Commit: `test: add failing test for [criterion]`

### GREEN Phase
1. Write the MINIMUM code to make the test pass
2. Run the test -- it MUST pass
3. Verify only the target test turned green (no side effects)
4. Commit: `feat: implement [criterion]`

### REFACTOR Phase
1. Clean up code while keeping ALL tests green
2. Remove duplication, improve naming, extract methods
3. Run full test suite -- ALL tests MUST pass
4. Commit: `refactor: clean up [area]`

## Compliance Scoring

| Score | Meaning |
|-------|---------|
| 90-100 | Exemplary TDD: all cycles followed correctly |
| 70-89 | Good TDD: minor deviations |
| 50-69 | Partial TDD: some implementation before tests |
| 0-49 | TDD violation: significant implementation without tests |

## Verification Methods

1. **Git History Analysis**: Test files must appear in commits before implementation files
2. **Coverage Analysis**: New code must have >90% test coverage
3. **Commit Message Convention**: RED/GREEN/REFACTOR phases identifiable in messages