Test-Driven Development

Drive implementation through tests using the red-green-refactor cycle.

Adapted from Matt Pocock's TDD skill

Trigger Patterns

• "use TDD"
• "TDD this feature"
• "red-green-refactor"
• "test-driven"
• "write tests first"

Do not activate for general "write tests for X" or "add test coverage" requests. This skill is specifically for the TDD workflow where tests lead implementation.

Philosophy

Test behavior, not implementation. Every test should verify what the code does from the outside, not how it works inside. See deep-modules.md for the reasoning behind this.