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C# and .NET Testing Patterns

Write C# and .NET tests with xUnit, FluentAssertions, mocking and integration tests

Repository
affaan-m/ECC
Stars
295,127
Licence
MIT
Files
1 file

What it does

This skill gives an AI agent a reference guide for writing automated tests in C# and .NET. Once installed, the agent follows the documented patterns: structuring unit tests (Arrange-Act-Assert), parameterised tests, mocking dependencies with NSubstitute or Moq, ASP.NET Core API tests with WebApplicationFactory, database tests with Testcontainers, and a suggested folder layout for test projects. It is guidance only; it does not run anything by itself.

Great for

  • C# developers who want consistent, readable xUnit tests
  • Teams setting up test projects for an ASP.NET Core or .NET application
  • Developers debugging slow or flaky tests who want a reference for better structure

Skip it if

  • Non-.NET languages such as Python or JavaScript, since the patterns are specific to C# and .NET
  • Projects that already have an established testing convention, where the agent may suggest conflicting styles
  • Anyone expecting the skill to execute tests or verify correctness itself; it only supplies example code and guidance

Try asking

  • “Write xUnit unit tests for my OrderService using FluentAssertions and NSubstitute”
  • “Set up WebApplicationFactory integration tests for my ASP.NET Core orders API”
  • “Use Testcontainers with PostgreSQL to test my repository layer”
  • “Help me convert these tests to parameterised [Theory] tests with InlineData”
Step-by-step guide: how to use C# and .NET Testing PatternsInstall, first run, examples, tips and FAQs

Install in 3 steps

  1. 1

    Download the skill

    The ZIP contains the 1 original files, the MIT licence and an attribution note.

    csharp-testing.zip
  2. 2

    Add it to your agent

    Claude Code (all projects)

    mkdir -p ~/.claude/skills && unzip csharp-testing.zip -d ~/.claude/skills/

    Claude Code / Agent SDK (this project only)

    mkdir -p .claude/skills && unzip csharp-testing.zip -d .claude/skills/

    Claude apps (web/desktop): Settings → Capabilities → Skills → Upload skill, and choose the ZIP.

  3. 3

    Ask for the task

    No special command needed — the agent reads the skill's description and loads it when your request matches. Try one of the prompts above.

Get better results

  • Name the libraries you already use (for example Moq instead of NSubstitute) so the agent adapts the examples to your project.
  • Ask the agent to check generated tests by running dotnet test yourself, since the skill does not verify code.
  • Share your existing test folder layout so the agent follows your conventions rather than the suggested tests/ structure.

What's inside

  • SKILL.md

Redistributed unmodified from affaan-m/ECC under the MIT licence. The assessment was drafted with AI from the skill's files on 2026-10-29. Skills can instruct your agent to run code — read SKILL.md and any scripts before installing.