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.
Install
npx skills add addyosmani/agent-skills --skill test-driven-developmentnpx skills add addyosmani/agent-skills --skill test-driven-development -a claude-code -gnpx skills add addyosmani/agent-skills --skill test-driven-development -a codex -ggemini skills install https://github.com/addyosmani/agent-skills.git --path skills/test-driven-developmentgh skill install addyosmani/agent-skills test-driven-developmentgit clone --depth 1 https://github.com/addyosmani/agent-skills /tmp/addyosmani__agent-skills
mkdir -p ~/.claude/skills ~/.agents/skills
cp -R /tmp/addyosmani__agent-skills/skills/test-driven-development ~/.claude/skills/test-driven-development # Claude Code
cp -R /tmp/addyosmani__agent-skills/skills/test-driven-development ~/.agents/skills/test-driven-development # Codex, Cursor, Gemini CLI, Copilot, OpenCode