Can I keep pre-written code as a reference when using this skill?

No, the skill's non-negotiable rules mandate deleting any production code written before the corresponding tests to ensure true test-driven design.

How does this skill handle bug fixes?

The skill requires you to write a test that reproduces the bug and fails first. This confirms the bug is understood and provides a permanent regression test once the fix is implemented.

What is the Red-Green-Refactor cycle in this skill?

It is a disciplined three-step process: first, write a failing test (Red); second, write the minimum code necessary to pass the test (Green); and third, optimize the code while keeping tests passing (Refactor).

Why does the TDD skill require tests to fail before implementation?

Verifying a test fails for the correct reason ensures that the test is actually evaluating the new feature or bug and isn't passing due to a false positive or existing code.

Test-Driven Development (TDD)

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

bysharpner

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Security & Testing

Enforces a disciplined Red-Green-Refactor workflow to ensure high-quality code through test-first implementation.

The Test-Driven Development (TDD) skill for Claude Code establishes a rigorous development framework where tests are written and verified as failing before any production code is authored. By following the strict Red-Green-Refactor cycle, it prevents regressions, eliminates the risk of untested edge cases, and ensures that every line of code serves a specific, verified purpose. This skill is particularly effective for complex feature development and bug fixing, providing a standardized reporting format to track progress through the testing cycle and rejecting common rationalizations for skipping tests.

Key Features

01Zero-tolerance policy for implementation-first coding

02Automated regression testing for bug reproduction and fixes

031 GitHub stars

04Standardized TDD progress reporting and status updates

05Strict Red-Green-Refactor cycle enforcement

06Mandatory failing test verification for all new logic

Use Cases

01Implementing complex business logic with 100% test coverage

02Refactoring existing code while maintaining functional integrity

03Fixing software bugs by creating reliable reproduction test cases

What are Skills?·How to Install

Install with 🐟 Skill.Fish

npx skillfish add sharpner/claude-agents tdd

For use in Claude.ai and ChatGPT

Download Skill