TDD Claude Skill — Test-Driven Development With Claude Guiding Every Step

Test-driven development is one of the most proven software engineering practices. Write a failing test, make it pass, refactor. The code that emerges from TDD is more modular, better tested, and easier to change than code written without tests.

But most developers skip TDD because the cycle feels slow — especially when you are under deadline pressure or working alone without a pairing partner to keep you on track.

The TDD Skill makes Claude your TDD pairing partner. It guides you through the red-green-refactor cycle, writes the failing tests first, then drives the implementation — keeping you in the TDD rhythm without the friction.

The TDD Cycle With Claude

Red — Write a failing test Claude writes the test first, before any implementation exists. The test defines exactly what the code should do.

Green — Make it pass Claude writes the minimum implementation to make the test pass. No extra features, no premature optimisation — just enough to go green.

Refactor — Clean it up With the test passing, Claude refactors the implementation for clarity and quality. The test catches any regressions immediately.

This cycle repeats for every feature, every function, every edge case.

What the TDD Skill Works For

Flutter widget tests — write widget tests before building the UI. Define what the widget should render, what interactions it should handle, what state it should manage.

Dart unit tests — test business logic, utility functions, and data transformations before writing the implementation.

Next.js API route tests — define the expected request/response contract before writing the Route Handler.

React component tests — test user interactions and rendering behaviour before building the component.

Utility and helper functions — any pure function that transforms data is an ideal TDD candidate.

How to Use the TDD Skill

Once installed, start any feature with:

I want to build a function that validates an email address.
Let's do this TDD style — write the failing tests first.

Claude writes the tests. You run them — they fail (red). Then:

Tests are failing. Now write the minimum implementation to make them pass.

Claude writes the implementation. You run the tests — they pass (green). Then:

Tests are green. Refactor the implementation for clarity.

Claude cleans up the code. Tests still pass. Feature complete with full test coverage.

How to Install the TDD Skill

1. Visit rohansurve.in/rohankit/skills/tdd for the install guide
2. Run:

npx skills add tdd

1. Start your next feature with tests first

TDD for Solo Developers

TDD is especially valuable when working alone because there is no second pair of eyes catching your assumptions. The tests force you to define what the code should do before you write it — which surfaces design problems early rather than after the implementation is complete.

With Claude as your TDD partner, you get the discipline of test-first development without needing a pairing partner.

Related RohanKit Skills

• Code Review Skill — review the implementation Claude writes in the green phase
• Flutter Development Skill — Flutter-specific context for TDD in Dart
• Next.js Full Stack Skill — Next.js context for API route and component TDD
• API Documentation Skill — document the tested API after TDD is complete
• Git Commit Messages Skill — commit each red-green-refactor cycle with clean messages

All free at rohansurve.in/rohankit.

Ship Code You Can Trust

The TDD Skill makes test-driven development the path of least resistance instead of the path of most discipline. Tests first, implementation second, confidence always.