TDD Tidy First Skill

Use this skill to keep code changes small, verifiable, and easy to review.

1. Core Defaults

• Prefer the smallest next step that can be verified quickly
• For behavioral changes, start with a failing test or minimal reproducer when that is cheap to add
• Implement only enough code to pass the new check
• Refactor only after the behavior is verified
• Keep structural changes separate from behavioral changes when practical

2. Red -> Green -> Refactor