What is the 'Iron Law' in this TDD skill?

The Iron Law states that no production code should be written without a failing test first. If code is written before a test, it must be deleted and rewritten after the test is established.

When can I skip TDD using this skill?

TDD is expected for almost all tasks. Exceptions include throwaway prototypes, generated code, or configuration files, and should be cleared with a human partner.

How does this skill handle bug fixes?

For bug fixes, the skill requires writing a test that reproduces the bug, verifying it fails, and then writing the minimal code necessary to make the test pass.

Does this skill work with existing codebases?

Yes, it is ideal for improving existing code by adding tests for new changes and ensuring that refactoring does not break current functionality.

Why does this skill require watching a test fail?

Watching a test fail (the Red phase) proves that the test is actually checking the intended behavior and that the failure isn't due to a typo or unrelated error.

Test-Driven Development (TDD) Protocol

Name: Test-Driven Development (TDD) Protocol
Author: Krosebrook

byKrosebrook

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セキュリティとテスト

Enforces a strict Red-Green-Refactor workflow to ensure all production code is verified by failing tests before implementation.

This skill implements a rigorous Test-Driven Development (TDD) framework for Claude, mandating that every feature or bug fix begins with a failing test. By following the 'Iron Law'—no production code without a prior test failure—it ensures high-quality, verifiable codebases and prevents the common pitfalls of testing after implementation. It guides Claude through the Red-Green-Refactor cycle, helping developers maintain a clean, regression-proof source of truth while strictly adhering to the best practices of software craftsmanship and behavioral verification.

主な機能

01Automated verification of test failure messages before coding

02Guidance on writing minimal, behavior-focused unit tests

03Strict Red-Green-Refactor cycle enforcement

04Iron Law compliance: prevents untested production code

05Comprehensive TDD verification checklist for work completion

061 GitHub stars

ユースケース

01Implementing new features with guaranteed logic coverage

02Refactoring legacy codebases while maintaining functional parity

03Fixing bugs by first reproducing them with a failing test case

What are Skills?·How to Install

Install with 🐟 Skill.Fish

npx skillfish add krosebrook/source-of-truth-monorepo test-driven-development

For use in Claude.ai and ChatGPT

Download Skill