tdd

Guide .NET development through the TDD red-green-refactor loop.

Updated Jan 9, 2026

Search Tags:#test-driven development #interface design #red-green-refactor #mocking #xUnit

Ready to run

npx skills add https://github.com/LeeSanderson/OpinionatedDotNetCodingStandards --skill tdd-leesanderson

💬 Prompt for ChatGPT / Claude Chat▼

Please help me install this Agent Skill.
Skill: tdd
Source: https://github.com/LeeSanderson/OpinionatedDotNetCodingStandards/tree/main/.claude/skills/tdd
Command: npx skills add https://github.com/LeeSanderson/OpinionatedDotNetCodingStandards --skill tdd-leesanderson

SYSTEM DOCUMENTATION & REQUIREMENTS

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

What problem does it solve?

This Skill guides developers through the test-driven development (TDD) process, providing a structured approach to building software with tests first, enhancing code quality and maintainability.

Core Features & Use Cases

TDD Workflow: Follows the TDD lifecycle with planning, tracer bullets, and incremental refactoring.
Best Practices: Encourages deep modules, public interfaces, and avoiding horizontal slicing.
Use Case: A developer looking to implement TDD for a .NET solution can use this Skill to learn how to design testable interfaces, write effective tests, and refactor code in a TDD context.

Quick Start

Apply the TDD Skill to start your new project with a well-structured test plan and a test for the first behavior.

Frequently Asked Questions about tdd

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

FAQPage Schema

What is the red-green-refactor workflow in test-driven development?▼

The red-green-refactor workflow in test-driven development is a lifecycle of writing a failing test, making it pass, and then incrementally refactoring the code to ensure tests act as a reliable safety net.

How do I design testable interfaces for .NET solutions using TDD?▼

To design testable interfaces for .NET solutions using TDD, you should focus on creating deep modules, establishing clear public interfaces, and avoiding horizontal slicing when planning your system boundaries.

When do I need mocking in test-driven development?▼

You need mocking in test-driven development when verifying the behavior of system boundaries, allowing you to isolate the code under test and design public interfaces without relying on external dependencies.

What is the best way to start a new .NET project with a test plan?▼

The best way to start a new .NET project with a test plan is to apply test-driven development by planning your approach, laying down tracer bullets, and writing a test for the first behavior.

Does test-driven development work with xUnit for .NET development?▼

Yes, test-driven development works effectively with xUnit for .NET development, providing a structured approach to building software with tests first to enhance code quality and maintainability.

Why should I avoid horizontal slicing when writing testable code?▼

You should avoid horizontal slicing when writing testable code because it undermines the creation of deep modules and clear public interfaces, making tests less effective as a reliable safety net during refactoring.