Testing Strategy

Unit Tests

public class CreateProductCommandHandlerTests
{
    [Fact]
    public async Task Handle_ValidProduct_ReturnsProductId()
    {
        // Arrange
        var context = new Mock<IApplicationDbContext>();
        var handler = new CreateProductCommandHandler(context.Object);
        var command = new CreateProductCommand("Test Product", 99.99m);

        // Act
        var result = await handler.Handle(command, CancellationToken.None);

        // Assert
        Assert.True(result > 0);
    }
}

Integration Tests

public class ProductsEndpointTests : IClassFixture<WebApplicationFactory<Program>>
{
    private readonly HttpClient _client;

    public ProductsEndpointTests(WebApplicationFactory<Program> factory)
    {
        _client = factory.CreateClient();
    }

    [Fact]
    public async Task GetProducts_ReturnsSuccessStatusCode()
    {
        var response = await _client.GetAsync("/api/products");
        response.EnsureSuccessStatusCode();
    }
}

Test Containers

dotnet add package Testcontainers

public class DatabaseFixture : IAsyncLifetime
{
    private readonly MsSqlContainer _container = new MsSqlBuilder().Build();

    public async Task InitializeAsync()
    {
        await _container.StartAsync();
    }

    public async Task DisposeAsync()
    {
        await _container.StopAsync();
    }
}