Test Driven Development

Drive behavior changes through failing tests, minimal implementation, and refactoring.

577|62|Updated May 15, 2026

Search Tags:#tdd #refactoring #unit-testing #development-workflow #test-driven-development

Ready to run

npx skills add https://github.com/agentic-in/elephant-agent --skill test-driven-development-agentic-in

💬 Prompt for ChatGPT / Claude Chat▼

Please help me install this Agent Skill.
Skill: Test Driven Development
Source: https://github.com/agentic-in/elephant-agent/tree/main/packages/skills/builtin_packages/software-development/test-driven-development
Command: npx skills add https://github.com/agentic-in/elephant-agent --skill test-driven-development-agentic-in

SYSTEM DOCUMENTATION & REQUIREMENTS

What problem does it solve?

Test Driven Development helps teams shape software behavior by starting from a failing test, implementing the smallest change that makes it pass, and then refactoring to improve design once the behavior is stabilized.

Core Features & Use Cases

Test-first workflow: define expected behavior via tests before implementing code.
Minimal implementation: make tests pass with the smallest change.
Refactor safely: clean up while preserving behavior after success.
Use Case: when introducing a new feature, the test drives the API contract and guides design decisions.

Quick Start

Identify the failing test, implement the smallest change to make it pass, then refactor to improve design after the behavior is locked.

Frequently Asked Questions about Test Driven Development

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

FAQPage Schema

How does test-driven development workflow guide software implementation?▼

Test-driven development workflow uses a failing test to drive the smallest working implementation, then cleans up the design once the behavior is locked. This ensures tests guide implementation and clarify requirements deterministically.

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

To start writing unit tests before implementation, identify a failing test that defines the expected behavior. Then implement the smallest change to make it pass, and finally refactor to improve the design while preserving the locked behavior.

Can I use test-driven development for refactoring existing code?▼

Yes, you can use test-driven development for refactoring existing code. The workflow supports refactoring safely by cleaning up and improving design after the behavior is stabilized and locked by passing tests.

What is the best way to enforce design decisions during feature development?▼

The best way to enforce design decisions during feature development is using a test-first approach. The test drives the API contract, clarifies requirements, and guides incremental changes to ensure the implementation matches the expected behavior.

What are the limitations of relying on a test-driven development workflow?▼

A key limitation of a test-driven development workflow is the risk of overreliance on fragile test suites. The workflow requires guardrails to prevent overreliance and ensure tests remain deterministic and effective during implementation.

Why does test-driven development require a failing test before implementation?▼

Test-driven development requires a failing test before implementation to clarify requirements and define the expected behavior. This failing test acts as a contract that guides the smallest working implementation and locks the behavior before refactoring.