test-driven-development

Enforce writing failing tests before implementation using the Red-Green-Refactor workflow.

8|4|Updated Dec 15, 2025

Search Tags:#testing #tdd #red-green-refactor #unit-tests #test-driven-development

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npx skills add https://github.com/Jst-Well-Dan/Skill-Box --skill test-driven-development-jst-well-dan

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Please help me install this Agent Skill.
Skill: test-driven-development
Source: https://github.com/Jst-Well-Dan/Skill-Box/tree/main/no-code-builder/test-driven-development
Command: npx skills add https://github.com/Jst-Well-Dan/Skill-Box --skill test-driven-development-jst-well-dan

SYSTEM DOCUMENTATION & REQUIREMENTS

What problem does it solve?

This Skill enforces writing failing tests before implementing features, ensuring you verify behavior before production code.

Core Features & Use Cases

Red-Green-Refactor cycle: write a failing test, implement minimal code to pass, then refactor for clarity.
Test-first discipline: ensures changes are validated by tests and guards against regressions.
Use Case: when implementing a new feature or bug fix, write tests first to verify expectations.

Quick Start

Use this skill to structure your testing workflow by writing a failing test first, then implementing the code to pass it.

Frequently Asked Questions about test-driven-development

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

FAQPage Schema

How do I write tests before implementing code?▼

Test-driven development starts by writing a failing test that describes your desired behavior, then implementing minimal production code to pass it. This Red-Green-Refactor cycle—fail, pass, refactor—ensures your code is validated by tests from the start and guards against regressions.

What is the Red-Green-Refactor workflow?▼

Red-Green-Refactor is a three-step cycle: write a failing test (Red), implement minimal code to pass it (Green), then improve code clarity without changing behavior (Refactor). This discipline ensures tests drive design and every feature has test coverage.

When should I use test-driven development?▼

Apply test-driven development when implementing new features, fixing bugs, refactoring existing code, or making behavior changes across codebases. Writing failing tests first verifies expectations and prevents regressions in all these scenarios.

Why write failing tests before production code?▼

Failing tests first enforce test-first discipline, ensuring every change is validated by tests and preventing untested code from entering production. This approach catches regressions early and confirms behavior works as intended.

Can I apply test-driven development to existing codebases?▼

Yes. Test-driven development works for bug fixes, refactoring, and new features in existing codebases. Write a failing test to capture the desired behavior or bug fix, then implement minimal code to pass—maintaining test-first discipline across your codebase.

What's the minimal code approach in TDD?▼

Minimal code means implementing only what's necessary to pass the failing test, avoiding speculation or over-engineering. This keeps changes well-scoped, focused on verified behavior, and easier to review and maintain.