tdd

Guide feature implementation with red-green-refactor test-driven development loops.

Updated Apr 16, 2026
One-click install
npx skills add https://github.com/ejoliet/claude-skills --skill tdd-ejoliet
Or copy as Structured Prompt for Agent
Please help me install this Agent Skill.
Skill: tdd
Source: https://github.com/ejoliet/claude-skills/tree/main/tdd
Command: npx skills add https://github.com/ejoliet/claude-skills --skill tdd-ejoliet

SYSTEM DOCUMENTATION & REQUIREMENTS

What problem does it solve?

Red-green-refactor driven development helps teams safely implement new features and refactors by enforcing a test-first workflow that validates behavior through public interfaces, reducing regressions and misaligned implementations.

Core Features & Use Cases

  • Vertical-slice tracer bullets guide incremental development from planning to implementation.
  • Planning, tracing, incremental loops, and refactoring steps ensure safe progression and test coverage.
  • Works across API endpoints, modules, and data processing features to maintain stability during change.

Quick Start

Write a single failing test for the new behavior, then implement the minimal code to pass, and repeat until the feature is complete.

Frequently Asked Questions about tdd

High-intent search queries and answers about installing and using this skill.

FAQPage Schema
How do I implement test-driven development using a red-green-refactor loop?

Test-driven development using a red-green-refactor loop involves writing a failing test for new behavior, implementing minimal code to pass it, and refactoring safely. This cycle validates behavior through public interfaces and reduces regressions.

What is the best way to start incremental development on a new API endpoint feature?

The best way to start incremental development on an API endpoint is using vertical-slice tracer bullets. This approach guides progression from planning to implementation while ensuring safe test coverage and stability during changes.

How does test-first workflow help with safe refactoring across modular components?

A test-first workflow helps safe refactoring across modular components by validating behavior through public interfaces before changes are made. This enforces a disciplined progression that maintains stability and reduces misaligned implementations.

Can I use red-green test cycles for bug fixes with regression tests?

Yes, you can use red-green test cycles for bug fixes by writing a failing regression test that captures the defect. Applying the test-first workflow validates the fix and prevents future regressions across API endpoints and modules.

When do I need to validate behavior through public interfaces during feature implementation?

You need to validate behavior through public interfaces during feature start, bug fixes with regression tests, and safe refactors. This test-driven approach ensures requirements are met for planning, tracer bullets, and incremental development workflows.