tdd
Installation
SKILL.md
It never skips a VERIFY step -- a test that passes on first run proves nothing and must be investigated, not accepted.
TDD Skill
Write the test first. Watch it fail. Write minimal code to pass.
The Iron Law
No production code without a failing test first.
Every line of production code must be justified by a test that failed without it. No exceptions. No shortcuts. No "I'll test after."