What is the golden rule of the TDD skill?

The core rule is that no production code should be written until a failing test (RED state) has been created and verified.

How do I start a new TDD session?

Simply use the /tdd command followed by your feature description, for example: '/tdd email validation function'.

Does it help identify edge cases?

Yes, the process includes a specific 'Test Case Derivation' step that looks for normal cases, error cases, and boundary values.

How does the skill handle different testing scopes?

It offers flags like --unit for isolated logic, --integration for multi-component testing, and --coverage for meeting specific test surface goals.

Is this skill limited to a specific programming language?

While it follows a standardized TDD methodology, it can be applied to any programming language or framework Claude supports.

Test-Driven Development (TDD)

Name: Test-Driven Development (TDD)
Author: Ho-Gyu-Lee

byHo-Gyu-Lee

0•

Security & Testing

Implements robust software through a strict Red-Green-Refactor cycle to ensure high code quality and reliability.

The TDD skill transforms Claude into a disciplined software engineer that adheres to the fundamental philosophy of Test-Driven Development: never write production code without a failing test. It guides users through a structured workflow that starts with interface definition and test case derivation—covering normal, error, and boundary conditions—before moving into the iterative cycle of implementation and refactoring. This skill is indispensable for developers who prioritize code maintainability, comprehensive test coverage, and the elimination of regression bugs from the start of the development process.

Key Features

010 GitHub stars

02Supports specialized modes for unit tests, integration tests, and coverage

03Defines function interfaces and signatures before writing logic

04Enforces a strict Red-Green-Refactor development cycle

05Provides real-time session tracking for current test status

06Automatically derives test cases for edge, error, and boundary conditions

Use Cases

01Building API endpoints with pre-defined success and failure scenarios

02Developing complex business logic with high accuracy requirements

03Refactoring existing code by establishing a test safety net first

What are Skills?·How to Install

Install with 🐟 Skill.Fish

npx skillfish add ho-gyu-lee/hello-claude-code tdd

For use in Claude.ai and ChatGPT