Tests in real browsers via Chrome DevTools MCP. Use when building or debugging anything that runs in a browser. Use when you need to inspect the DOM, capture console errors, analyze network requests, profile performance, or verify visual output with real runtime data. Requires the chrome-devtools MCP server to be configured.
test-driven-development
test-driven-development is an open-source testing skill for Claude Code and compatible agents, published by addyosmani. Its author describes it as: “Drives development with tests. 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…”. The project has 88k stars on GitHub and is available under the MIT license. Add it to your setup with `/plugin marketplace add addyosmani/agent-skills`.
What test-driven-development does
Write a failing test before writing the code that makes it pass. For bug fixes, reproduce the bug with a test before attempting a fix. Tests are proof — "seems right" is not done. A codebase with good tests is an AI agent's superpower; a codebase without tests is a liability.
Installation
Add test-driven-development to your agent with:
/plugin marketplace add addyosmani/agent-skillsAlways review a skill's source before installing it. This command comes from the skill's public repository; the linked repo is the source of truth for exact setup steps.
What's inside
The SKILL.md for test-driven-development is organised into these sections:
- Overview
- When to Use
- Discover the Stack First
- The TDD Cycle
- Step 1: RED — Write a Failing Test
- Step 2: GREEN — Make It Pass
- Step 3: REFACTOR — Clean Up
- The Prove-It Pattern (Bug Fixes)
- The Test Pyramid
- Test Sizes (Resource Model)
- Decision Guide
- Writing Good Tests
When to use it
Reach for test-driven-development when you want testing help from your agent without writing the same instructions every session. Load the skill and the agent picks it up automatically for relevant tasks.
Strengths
- Clear MIT license — safe to read and adapt
- Ships in addyosmani/agent-skills, an established project with 88,280 GitHub stars
- Actively maintained (recent commits)
Topics
Frequently asked questions
- What does test-driven-development do?
- Drives development with tests. 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.
- How do I install test-driven-development?
- Run /plugin marketplace add addyosmani/agent-skills in your agent, then reload your skills. Review the source at https://github.com/addyosmani/agent-skills before installing.
- Is test-driven-development free to use?
- Yes. test-driven-development is free and open source under the MIT license, so you can read, run, and adapt it within that license's terms.
- Where does test-driven-development come from?
- test-driven-development ships inside addyosmani/agent-skills, a repository that contains 25 catalogued skills in total. The repository's 88,280 GitHub stars apply to that whole collection, not to this skill on its own.
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