Is this skill compatible with existing codebases?

Yes, it encourages adding tests for new changes and bug fixes even in legacy projects to systematically improve code quality and prevent regressions.

How does this skill handle the Red-Green-Refactor cycle?

It guides the developer through writing a minimal failing test (Red), implementing just enough code to pass (Green), and then cleaning up the code without changing behavior (Refactor).

Why is watching a test fail mandatory?

Watching a test fail proves that the test actually checks the intended logic and isn't passing by accident or due to existing behavior.

Can I skip TDD for simple fixes?

The skill emphasizes that even 'simple' code breaks; skipping TDD is seen as technical debt, though exceptions can be discussed with a human partner for throwaway prototypes.

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

The Iron Law mandates that no production code should be written without a failing test first; any code written beforehand must be deleted to ensure true test-first development.

Test-Driven Development (TDD)

Name: Test-Driven Development (TDD)
Author: ben-mad-jlp

byben-mad-jlp

Security & Testing

Enforces a strict Red-Green-Refactor workflow to ensure high-quality, bug-free production code through mandatory failing tests.

About

The Test-Driven Development (TDD) skill provides Claude with a rigorous framework for software development, prioritizing test creation before implementation. By following the 'Iron Law'—no production code without a failing test first—it ensures that every feature and bug fix is verified against actual requirements rather than assumptions. This skill guides Claude through the full TDD cycle, including failure verification, minimal code implementation, and safe refactoring, resulting in more maintainable, reliable, and well-documented codebases.

Key Features

Promotes minimal code implementation to satisfy test requirements
Ensures mandatory verification of failing tests to prevent false positives
Enforces the Red-Green-Refactor cycle for all features and bug fixes
0 GitHub stars
Eliminates technical debt by preventing unverified production code
Provides systematic refactoring guidance while maintaining green test states

Use Cases

Implementing new features with clear behavioral specifications
Fixing bugs by reproducing them with a failing test first
Safe refactoring of legacy code by establishing a test baseline

About

Key Features

Promotes minimal code implementation to satisfy test requirements
Ensures mandatory verification of failing tests to prevent false positives
Enforces the Red-Green-Refactor cycle for all features and bug fixes
0 GitHub stars
Eliminates technical debt by preventing unverified production code
Provides systematic refactoring guidance while maintaining green test states

Use Cases

Implementing new features with clear behavioral specifications
Fixing bugs by reproducing them with a failing test first
Safe refactoring of legacy code by establishing a test baseline