tdd

Guide test-driven development workflows with red-green-refactor and behavior-focused tests.

9|Updated Feb 14, 2026
One-click install
npx skills add https://github.com/koolamusic/claudefiles --skill tdd-koolamusic
Or copy as Structured Prompt for Agent▼
Please help me install this Agent Skill.
Skill: tdd
Source: https://github.com/koolamusic/claudefiles/tree/main/skills/tdd
Command: npx skills add https://github.com/koolamusic/claudefiles --skill tdd-koolamusic

SYSTEM DOCUMENTATION & REQUIREMENTS

What problem does it solve?

This Skill helps developers avoid fragile tests and unclear requirements by guiding them through test-driven development focused on observable behavior, public interfaces, and incremental implementation.

Core Features & Use Cases

  • Red-Green-Refactor Workflow: Guides feature development and bug fixes through writing failing tests, implementing minimal solutions, and refactoring safely.
  • Behavior-Focused Testing: Encourages integration-style tests that validate user-facing behavior instead of implementation details.
  • Use Case: Apply this Skill when building a new feature, fixing a regression, designing testable interfaces, or preventing refactor-related test failures.

Quick Start

Ask the tdd skill to help me implement this feature using a red-green-refactor workflow with behavior-focused tests.

Frequently Asked Questions about tdd

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

FAQPage Schema
How do I write test-driven development tests that focus on behavior instead of implementation details?▼

Test-driven development tests should validate software behavior through public interfaces rather than internal implementation details. By using integration-style tests and boundary-aware mocking, you ensure tests remain reliable during refactoring and accurately reflect user-facing behavior.

What is the red-green-refactor workflow for implementing new features?▼

The red-green-refactor workflow involves writing a failing test to define desired behavior, implementing the minimal code required to pass that test, and then safely refactoring the solution. This incremental test-first development approach ensures reliable feature implementation and bug fixes.

How do I prevent my integration tests from breaking when refactoring code?▼

To prevent integration tests from breaking during refactoring, design tests around observable behavior and public interfaces. Avoid coupling tests to internal implementation details, apply boundary-aware mocking, and use compile-time type validation to verify structural changes safely.

When should I use test-driven development for fixing a regression?▼

Test-driven development is ideal for fixing regressions because it forces you to first write a failing test that reproduces the specific bug. This validates the software behavior through a public interface, ensuring your minimal solution actually resolves the issue without side effects.

Does test-driven development work for designing testable interfaces?▼

Test-driven development works effectively for designing testable interfaces because it applies a behavior-first approach. By defining software behavior through public interfaces and vertical slicing before implementation, you ensure the resulting API is inherently testable and reliable.

What's the difference between behavior-focused tests and standard unit tests?▼

Behavior-focused tests validate user-facing software behavior through public interfaces, whereas standard unit tests often verify internal implementation details. The behavior-first approach uses integration-style tests and boundary-aware mocking to ensure refactoring does not cause fragile test failures.