test-driven-development

Prompts iterative cycles of writing a failing test, then minimal code to pass it.

Updated Dec 18, 2025
One-click install
npx skills add https://github.com/malston/diego-capacity-analyzer --skill test-driven-development-malston
Or copy as Structured Prompt for Agent▼
Please help me install this Agent Skill.
Skill: test-driven-development
Source: https://github.com/malston/diego-capacity-analyzer/tree/main/.devcontainer/claude-config/.library/skills/test-driven-development
Command: npx skills add https://github.com/malston/diego-capacity-analyzer --skill test-driven-development-malston

SYSTEM DOCUMENTATION & REQUIREMENTS

What problem does it solve?

This Skill guides developers to adopt a test-driven development approach, ensuring that code behavior is verified by failing tests before implementation and reducing regressions.

Core Features & Use Cases

  • Red-Green-Refactor workflow: write a failing test, implement minimal code to pass, then refactor with confidence.
  • Regression prevention: maintain a test suite that guards against new bugs during feature fixes and refactoring.
  • Design-first discipline: encourages clear interfaces and incremental development across features.

Quick Start

  • Write a failing unit test for the new feature or bug fix.
  • Implement the minimal production code required to make the test pass.
  • Refactor the codebase for readability and maintainability, rerun tests, and iterate.

Frequently Asked Questions about test-driven-development

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

FAQPage Schema
What is test-driven development and how does it prevent code regressions?▼

Test-driven development is a tests-first approach where you write a failing unit test before production code, ensuring behavior is verified upfront and reducing regressions during feature development and bug fixes.

How do I apply the red-green-refactor workflow during feature development?▼

To apply red-green-refactor, write a failing unit test for the feature, implement minimal code to pass it, then refactor for readability and maintainability while rerunning tests to iterate.

Does test-driven development work for refactoring existing code?▼

Yes, test-driven development works for refactoring by maintaining a test suite that guards against new bugs, allowing you to refactor codebases for readability and maintainability with confidence.

What's the best way to start writing unit tests before implementation?▼

The best way to start is to write a failing unit test defining the new feature or bug fix, implement minimal production code to pass it, then refactor while rerunning tests to iterate.

When should I not use a test-first approach for software engineering?▼

A test-first approach may not suit projects lacking clear interfaces or incremental development goals, as it relies on design-first discipline to guide incremental feature implementation across the codebase.