test-driven-development
Use when implementing any feature or bugfix, before writing implementation code
Profile →npx skills add sickn33/agentic-awesome-skills --skill test-driven-development --agent claude-code
Same command for any agent — swap --agent for codex, cursor, copilot.
Weekly change comes from our own snapshots, not the repository page — it measures attention, not adoption.
# Test-Driven Development (TDD) ## Overview Write the test first. Watch it fail. Write minimal code to pass. **Core principle:** If you didn't watch the test fail, you don't know if it tests the right thing. **Violating the letter of the rules is violating the spirit of the rules.** ## When to Use **Always:** - New features - Bug fixes - Refactoring - Behavior changes **Exceptions (ask your human partner):** - Throwaway prototypes - Generated code - Configuration files Thinking "skip TDD just this once"? Stop. That's rationalization. ## The Iron Law ``` NO PRODUCTION CODE WITHOUT A FAILING TEST FIRST ``` Write code before the test? Delete it. Start over. **No exceptions:** - Don't keep it as "reference" - Don't "adapt" it while writing tests - Don't look at it - Delete means delete Implement fresh from tests. Period. ## Red-Green-Refactor ```dot digraph tdd_cycle { rankdir=LR; red [label="RED\nWrite failing test", shape=box, style=filled, fillcolor="#ffcccc"]; verify_red [label="Verify fails\ncorrectly", shape=diamond]; green [label="GREEN\nMinimal code", shape=box, style=filled, fillcolor="#ccffcc"]; verify_green [label="Verify passes\nAll green", shape=diamond]; refactor [label="
- Overview
- When to Use
- The Iron Law
- Red-Green-Refactor
- RED - Write Failing Test
- Verify RED - Watch It Fail
- GREEN - Minimal Code
- Verify GREEN - Watch It Pass
- REFACTOR - Clean Up
- Repeat
- Good Tests
- Why Order Matters
- Common Rationalizations
- Red Flags - STOP and Start Over
npm test path/to/test.test.ts npm test PASS
What does the test-driven-development skill do?
Use when implementing any feature or bugfix, before writing implementation code
How do I install it?
Run `npx skills add sickn33/agentic-awesome-skills --skill test-driven-development --agent claude-code` — it drops the skill into your project so the agent can pick it up. Swap the --agent value for codex, cursor or copilot if you use one of those.
Where does this skill come from?
From sickn33/agentic-awesome-skills, a repository with 44,414 stars. We read it straight from the repository tree rather than a submitted listing, so what you see here is what is actually published.
Is a popular skill a good skill?
Not necessarily. Stars measure attention, not adoption — a repository can trend for a week and be abandoned. That is why we show the weekly change from our own snapshots next to the total, instead of a single flattering number.