csharp-testing

Guide C#/.NET testing with xUnit, Moq, NSubstitute, and Coverlet.

Updated Aug 27, 2026

Search Tags:#tdd #integration testing #unit testing #code coverage #mocking #c##.net

Ready to run

npx skills add https://github.com/digitalhand/claude-skills-agents --skill csharp-testing

💬 Prompt for ChatGPT / Claude Chat▼

Please help me install this Agent Skill.
Skill: csharp-testing
Source: https://github.com/digitalhand/claude-skills-agents/tree/main/skills/csharp-testing
Command: npx skills add https://github.com/digitalhand/claude-skills-agents --skill csharp-testing

SYSTEM DOCUMENTATION & REQUIREMENTS

What problem does it solve?

This Skill streamlines the process of writing robust and maintainable C# code by providing a comprehensive guide to Test-Driven Development (TDD) and various testing frameworks and patterns.

Core Features & Use Cases

TDD Workflow: Implement the Red-Green-Refactor cycle for writing effective tests.
Unit Testing: Utilize xUnit for writing unit tests, including Facts and Theories.
Mocking: Learn to use Moq and NSubstitute for isolating dependencies.
Assertions: Employ FluentAssertions for clear and expressive test assertions.
Integration Testing: Set up integration tests using WebApplicationFactory for ASP.NET Core applications.
Database Testing: Integrate Testcontainers for realistic database testing environments.
Code Coverage: Configure and utilize Coverlet for measuring test coverage.

Quick Start

Write a failing xUnit test for a new C# feature, then implement the minimal code to make it pass.

Frequently Asked Questions about csharp-testing

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

FAQPage Schema

How do I start Test-Driven Development in C# .NET?▼

Start Test-Driven Development in C# by writing a failing xUnit test for a new feature, then implement minimal code to pass it. This guides users through the Red-Green-Refactor cycle.

What is the best way to mock dependencies for xUnit tests in .NET?▼

Mock dependencies for xUnit tests using Moq or NSubstitute to isolate components. This allows you to verify interactions and isolate the system under test without external side effects.

How do I set up integration testing for ASP.NET Core applications?▼

Set up integration testing for ASP.NET Core using WebApplicationFactory. This creates a test server host to run end-to-end API tests within your .NET testing pipeline.

Does Testcontainers work for .NET database testing?▼

Testcontainers works for .NET database testing by spinning up realistic, ephemeral database environments in Docker. This ensures your integration tests run against actual database instances.

How do I measure C# code coverage with Coverlet?▼

Measure C# code coverage by configuring Coverlet to collect test execution data alongside xUnit runs. This generates coverage reports to identify untested code paths in your .NET application.

Why use FluentAssertions instead of standard xUnit asserts?▼

FluentAssertions provides clear and expressive test assertions for .NET compared to standard xUnit asserts. It improves test readability and generates detailed failure messages to speed up debugging.