# Test Driven Development · Addy Osmani

Drives development with tests using the red\-green\-refactor loop\.

Canonical: https://claudelist.com/listings/skill-addyosmani-agent-skills-test-driven-development

Category: Skills

Source: community · Addy Osmani

Source checked: 2026-10-14

Website: https://github.com/addyosmani/agent-skills/tree/main/skills/test-driven-development

Drives development with tests using the red-green-refactor loop. Use when implementing any logic, fixing any bug, or changing any behavior. Use when you need to prove that code works, when a bug report arrives, or when you're about to modify existing functionality. Use when asked to add tests to a function, fix a bug in it or change its behavior, even when the code is pasted inline and the request does not mention tests.

## Install or set up

1. Review this skill’s `SKILL.md` and any prerequisites at the source.
2. From the project where you use Claude Code, run the command below. It installs only this skill into project scope; add `-g` for your personal scope.
3. Restart Claude Code and invoke `/test-driven-development` or ask Claude to use the skill. If it does not appear, check `.claude/skills/` and the source’s setup notes.

```sh
npx skills add https://github.com/addyosmani/agent-skills/tree/main/skills/test-driven-development --agent claude-code
```

Installation guide: https://github.com/addyosmani/agent-skills/tree/main/skills/test-driven-development