# Tdd

> Write a minimal failing test before implementation, make it pass with the simplest code, and refactor cleanly. Use when implementing bug fixes or features with clear verification targets.

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

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# Test-Driven Development (TDD)

1. Understand the exact requirement or bug and identify the narrowest executable check.
2. Write the failing test first. Ensure it fails for the expected reason, not a setup or syntax error.
3. Implement the minimal production code needed to make the failing test pass. Avoid speculative features.
4. Re-run the test to confirm green.
5. Refactor: clean up names, remove duplication, and simplify structure while keeping tests green.
6. Verify adjacent tests and broader contracts to ensure no regressions.