Why does the skill insist on deleting code written before a test?

Writing tests after code often leads to confirmation bias where you only test what you built rather than what is required. Deleting and restarting ensures the test actually validates the intended behavior.

How does this skill handle the 'Red' phase of TDD?

It requires writing a minimal test and running it to watch it fail. This confirms that the test is actually checking for the missing feature and not failing due to syntax errors or typos.

When should I skip TDD according to this skill?

TDD should always be used for new features, bug fixes, and refactoring. Exceptions are only allowed for throwaway prototypes, generated code, or configuration files, and usually require human confirmation.

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

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

Test-Driven Development (TDD)

Name: Test-Driven Development (TDD)
Author: claudiodearaujo

byclaudiodearaujo

0•

Security & Testing

Enforces a strict Red-Green-Refactor workflow to ensure high-quality, bug-free production code through disciplined testing.

This skill implements a rigorous Test-Driven Development (TDD) framework for Claude, adhering to the 'Iron Law' that no production code is written without a preceding failing test. It guides developers through the complete lifecycle of software creation—from writing minimal failing tests and verifying failures to implementing the simplest possible solution and refactoring for excellence. By eliminating common rationalizations for skipping tests, this skill helps teams build robust, self-documenting systems that are easy to maintain and refactor with confidence.

Key Features

01Strict Red-Green-Refactor cycle enforcement

020 GitHub stars

03Minimalist coding guidance to avoid over-engineering (YAGNI)

04Verification checklists for ensuring complete test coverage

05Mandatory verification of failing tests to prevent false positives

06Comprehensive troubleshooting for common TDD anti-patterns

Use Cases

01Fixing bugs by reproducing them with failing tests before applying fixes

02Implementing new features with built-in behavioral documentation and safety nets

03Safe refactoring of legacy code by establishing a baseline of automated tests

What are Skills?·How to Install

Install with 🐟 Skill.Fish

npx skillfish add claudiodearaujo/izacenter test-driven-development

For use in Claude.ai and ChatGPT

Key Features

01Strict Red-Green-Refactor cycle enforcement

020 GitHub stars

03Minimalist coding guidance to avoid over-engineering (YAGNI)

04Verification checklists for ensuring complete test coverage

05Mandatory verification of failing tests to prevent false positives

06Comprehensive troubleshooting for common TDD anti-patterns

Use Cases

01Fixing bugs by reproducing them with failing tests before applying fixes

02Implementing new features with built-in behavioral documentation and safety nets

03Safe refactoring of legacy code by establishing a baseline of automated tests

What are Skills?·How to Install

Install with 🐟 Skill.Fish

npx skillfish add claudiodearaujo/izacenter test-driven-development

For use in Claude.ai and ChatGPT