Frinkware.Testing.WebApplicationFactory 1.1.0

Frinkware.Testing.WebApplicationFactory

A NuGet package that provides a simple XUnit fixture class for behavioral testing in ASP.NET Core applications. This library wraps Microsoft.AspNetCore.Mvc.Testing.WebApplicationFactory to simplify test setup with Moq-based mocking and reusable test contexts.

Features

• Behavioral Test Context: Reuse a single WebApplicationFactory instance across multiple tests in a class
• Mock Management: Built-in Moq integration with automatic behavioral reset between tests
• Simple API: Create mocks and HTTP clients with minimal boilerplate
• XUnit Integration: Works seamlessly as an XUnit class fixture

Installation

dotnet add package Frinkware.Testing.WebApplicationFactory

Quick Start

Basic Usage

using Frinkware.Testing.WebApplicationFactory;
using Xunit;

public class MyApiTests : IClassFixture<BehavioralTestContext<Program>>
{
    private readonly BehavioralTestContext<Program> _context;
    private readonly Mock<IMyService> _myServiceMock;

    public MyApiTests(BehavioralTestContext<Program> context)
    {
        _context = context;
        
        // Mock out your dependencies
        _myServiceMock = context.Mock<IMyService>();
        _myServiceMock
            .Setup(x => x.GetDataAsync())
            .ReturnsAsync("test data");
    }

    [Fact]
    public async Task MyEndpoint_ShouldReturnExpectedData()
    {
        // Arrange
        var client = _context.CreateClient();

        // Act
        var response = await client.GetAsync("/api/myendpoint");

        // Assert
        response.EnsureSuccessStatusCode();
        var content = await response.Content.ReadAsStringAsync();
        Assert.Contains("test data", content);
    }
    
    [Fact]
    public async Task AnotherTest_MocksAreReset()
    {
        // The mock is automatically reset between tests
        // You can set up new behavior for this test
        _myServiceMock
            .Setup(x => x.GetDataAsync())
            .ReturnsAsync("different data");
            
        var client = _context.CreateClient();
        // ... test continues
    }
}

How It Works

BehavioralTestContext<TEntryPoint>

The BehavioralTestContext<TEntryPoint> class is the main public API:

• Mock<T>(MockBehavior behavior = MockBehavior.Default): Creates a mock and registers it with the test application's dependency injection container. Mocks are automatically reset between tests.

• CreateClient(): Creates an HttpClient configured to call your test application.

• CreateClient(WebApplicationFactoryClientOptions options): Creates an HttpClient with custom options.

Important Notes

• Mock Early: All mocks must be created in your test class constructor, before calling CreateClient() for the first time
• Automatic Reset: Mocks are automatically reset when accessed in subsequent tests, clearing all setups and verifications
• One Factory: The same WebApplicationFactory instance is shared across all tests in the class for performance

Example: Testing a Weather API

public class WeatherForecastTests : IClassFixture<BehavioralTestContext<Program>>
{
    private readonly BehavioralTestContext<Program> _context;
    private readonly Mock<IWeatherService> _weatherServiceMock;

    public WeatherForecastTests(BehavioralTestContext<Program> context)
    {
        _context = context;
        _weatherServiceMock = context.Mock<IWeatherService>();
    }

    [Fact]
    public async Task GetWeather_ReturnsSunny()
    {
        // Arrange
        _weatherServiceMock
            .Setup(x => x.GetForecastAsync())
            .ReturnsAsync(new[] { new WeatherForecast { Summary = "Sunny" } });

        var client = _context.CreateClient();

        // Act
        var response = await client.GetAsync("/weatherforecast");

        // Assert
        response.EnsureSuccessStatusCode();
        var forecast = await response.Content.ReadFromJsonAsync<WeatherForecast[]>();
        Assert.Equal("Sunny", forecast[0].Summary);
    }
}

Dependencies

• .NET 8.0+
• Microsoft.AspNetCore.Mvc.Testing 8.0.0+
• Moq 4.20.70+
• xunit.core 2.6.6+

License

MIT

Contributing

Contributions are welcome! Please feel free to submit issues or pull requests at GitHub.