test-driven-development

Drive development with tests written before implementation using the red-green-refactor workflow.

1|Updated Apr 28, 2026

Search Tags:#testing #tdd #quality #regression #red-green-refactor #unit-tests

Ready to run

npx skills add https://github.com/yolo-labs-hq/yolo-skills-registry --skill test-driven-development-yolo-labs-hq

💬 Prompt for ChatGPT / Claude Chat▼

Please help me install this Agent Skill.
Skill: test-driven-development
Source: https://github.com/yolo-labs-hq/yolo-skills-registry/tree/main/skills/test-driven-development
Command: npx skills add https://github.com/yolo-labs-hq/yolo-skills-registry --skill test-driven-development-yolo-labs-hq

SYSTEM DOCUMENTATION & REQUIREMENTS

What problem does it solve?

Writing tests before implementing logic prevents hidden bugs, clarifies desired behavior, and guards against regressions by making expectations explicit.

Core Features & Use Cases

Promotes the Red-Green-Refactor cycle to rapidly validate behavior.
Uses reproduction tests for bug fixes to prevent regressions.
Improves design confidence during refactors and feature additions.

Quick Start

Begin by writing a failing test for the feature you plan to implement, then write the minimal code to make the test pass.

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 regressions?▼

Test-driven development is a workflow where you write tests before implementation, making expectations explicit to prevent hidden bugs and guard against regressions as code evolves. It clarifies desired behavior by requiring reproducible tests.

How do I start writing unit tests before implementing new features?▼

To start writing unit tests before implementation, begin by writing a failing test for the feature you plan to implement, then write the minimal code required to make that test pass. This follows the red-green-refactor cycle.

Can I use test-driven development for bug fixes and refactoring large codebases?▼

Yes, test-driven development is applicable to bug fixes and refactors across projects, from small modules to large codebases. It uses reproduction tests for bug fixes to prevent regressions and improves design confidence during refactors.

What is the red-green-refactor cycle in unit testing?▼

The red-green-refactor cycle is a unit testing workflow where you write a failing test, implement minimal code to make it pass, and then refactor. This process rapidly validates behavior and ensures software correctness through disciplined test maintenance.

Does test-driven development work without any external testing dependencies?▼

Test-driven development requires no external dependencies to implement the red-green-refactor workflow. It relies on reproducible tests and disciplined test maintenance to guarantee behavior as code evolves, rather than specific testing frameworks.

Why does writing tests after implementation lead to hidden bugs?▼

Writing tests after implementation leads to hidden bugs because it fails to clarify desired behavior upfront. Test-driven development solves this by making expectations explicit before logic is written, preventing hidden bugs and guarding against regressions.