csharp-testing

npx skills add mturac/everything-openai-codex --skill csharp-testing --agent codex

Same command for any agent — swap --agent for claude-code, cursor, copilot.

# C# Testing Patterns Comprehensive testing patterns for .NET applications using xUnit, FluentAssertions, and modern testing practices. ## When to Activate - Writing new tests for C# code - Reviewing test quality and coverage - Setting up test infrastructure for .NET projects - Debugging flaky or slow tests ## Test Framework Stack | Tool | Purpose | |---|---| | **xUnit** | Test framework (preferred for .NET) | | **FluentAssertions** | Readable assertion syntax | | **NSubstitute** or **Moq** | Mocking dependencies | | **Testcontainers** | Real infrastructure in integration tests | | **WebApplicationFactory** | ASP.NET Core integration tests | | **Bogus** | Realistic test data generation | ## Unit Test Structure ### Arrange-Act-Assert ```csharp public sealed class OrderServiceTests { private readonly IOrderRepository _repository = Substitute.For<IOrderRepository>(); private readonly ILogger<OrderService> _logger = Substitute.For<ILogger<OrderService>>(); private readonly OrderService _sut; public OrderServiceTests() { _sut = new OrderService(_repository, _logger); } [Fact] public async Task PlaceOrderAsync_ReturnsSuccess_WhenRequestIsValid() { // Arrange var request = new CreateOrder

Run all tests
dotnet test
Run with coverage
dotnet test --collect:"XPlat Code Coverage"
Run specific project
dotnet test tests/MyApp.UnitTests/
Filter by test name
dotnet test --filter "FullyQualifiedName~OrderService"
Watch mode during development
dotnet watch test --project tests/MyApp.UnitTests/