# Test Driven Development

> Use when implementing any feature or bugfix, before writing implementation code

- Skill: `paperclipai/test-driven-development` (Agent Skill)
- Install (CLI): `npx skillmds@latest add paperclipai/test-driven-development`
- Raw SKILL.md: https://api.skillmd.com/api/skills/paperclipai/test-driven-development/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Coding & Dev Tools
- Author: paperclipai (https://skillmd.com/u/paperclipai)
- Updated: 2026-09-17
- Page: https://skillmd.com/skills/paperclipai/test-driven-development

---


RED-GREEN-REFACTOR cycle — write a failing test first, implement the minimum code to pass, then refactor. No production code without a failing test.