outside-in-tdd

Orchestrate Outside-In TDD workflows from end-to-end tests to unit tests.

25|3|Updated Mar 10, 2026
One-click install
npx skills add https://github.com/JoeGaebel/outside-in-tdd-starter --skill outside-in-tdd
Or copy as Structured Prompt for Agent▼
Please help me install this Agent Skill.
Skill: outside-in-tdd
Source: https://github.com/JoeGaebel/outside-in-tdd-starter/tree/main/.claude/skills/outside-in-tdd
Command: npx skills add https://github.com/JoeGaebel/outside-in-tdd-starter --skill outside-in-tdd

SYSTEM DOCUMENTATION & REQUIREMENTS

💡 This Skill includes scripts (resource) and references (resource) components.

What problem does it solve?

This Skill automates the process of implementing new features using a strict Outside-In Test-Driven Development (TDD) methodology, ensuring code quality and comprehensive test coverage from the start.

Core Features & Use Cases

  • Automated TDD Workflow: Guides the AI through planning, writing failing tests (E2E down to unit), implementing code, and refactoring.
  • Layered Testing: Enforces testing at the appropriate architectural layer, starting from E2E and drilling down.
  • Use Case: When you request a new feature, like adding a user profile editing function, this Skill will automatically orchestrate the entire TDD process, writing all necessary tests and code before completion.

Quick Start

Use the outside-in-tdd skill to implement the dark mode toggle feature.

Frequently Asked Questions about outside-in-tdd

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

FAQPage Schema
What is outside-in TDD and how does it guide feature implementation?▼

Outside-in TDD is a development workflow that starts with end-to-end tests and progressively drills down to unit tests across architectural layers. It guides implementation by cycling through failing tests, writing code to pass them, and refactoring.

How do I implement a new feature using test-driven development from end-to-end tests down to units?▼

You can implement a feature by triggering an automated TDD workflow that plans the feature, writes failing end-to-end tests first, drills down through architectural layers to unit tests, implements the code, and refactors until all tests pass.

Can I use this outside-in TDD workflow to build any type of application feature?▼

Yes, this workflow triggers automatically for new feature implementation requests. It orchestrates the strict outside-in testing methodology to build features by enforcing testing at each appropriate architectural layer, starting from end-to-end down to units.

What is the difference between outside-in TDD and traditional unit-first test-driven development?▼

Outside-in TDD starts from end-to-end tests to define the feature's external behavior, then progressively drills down to unit tests across architectural layers. Traditional unit-first TDD starts with isolated component tests and builds outward, often lacking comprehensive end-to-end coverage from the start.

Does this TDD workflow handle the refactoring phase automatically after tests pass?▼

Yes, the workflow guides the AI through the complete refactoring phase for each architectural layer after the implementation reaches a passing state. It ensures code quality is maintained while keeping all end-to-end and unit tests green.

When should I not use an outside-in testing approach for feature development?▼

You should avoid outside-in TDD when building features with unclear or rapidly changing external requirements, as rewriting end-to-end tests repeatedly becomes costly. It suits features where defining the expected external behavior upfront is feasible.