Frinkware.Testing.WebApplicationFactory 1.0.0

Frinkware.Testing.WebApplicationFactory

A NuGet package that provides a custom XUnit fixture class library for behavioral testing in ASP.NET Core applications. This library wraps Microsoft.AspNetCore.Mvc.Testing.WebApplicationFactory to simplify test setup, mock configuration, and test context reuse.

Features

• Configurable Web Application Factory: Easily configure test services and command-line arguments
• Behavioral Test Context Fixture: Reuse WebApplicationFactory across multiple tests in a class
• Mock Management: Built-in support for Moq with behavioral reset capabilities
• Service Replacement: Simple extension methods for replacing services with mocks
• Hosted Service Control: Automatically filter out background services during tests
• Default Value Provider: Set up default return values for mocked dependencies

Installation

dotnet add package Frinkware.Testing.WebApplicationFactory

Quick Start

Basic Usage

using Frinkware.Testing.WebApplicationFactory;
using Xunit;

public class MyApiTests : IClassFixture<BehavioralTestContextFixture<Startup>>
{
    private readonly HttpClient _httpClient;
    private readonly Mock<IMyService> _myServiceMock;

    public MyApiTests(BehavioralTestContextFixture<Startup> fixture)
    {
        // Mock out your dependencies
        _myServiceMock = fixture.Mock<IMyService>();
        _myServiceMock
            .Setup(x => x.GetDataAsync())
            .ReturnsAsync("test data");

        // Create an HTTP client
        _httpClient = fixture.CreateClient();
    }

    [Fact]
    public async Task MyEndpoint_ShouldReturnExpectedData()
    {
        // Act
        var response = await _httpClient.GetAsync("/api/myendpoint");

        // Assert
        response.EnsureSuccessStatusCode();
        var content = await response.Content.ReadAsStringAsync();
        Assert.Contains("test data", content);
    }
}

Using WithDefault for Simpler Mock Setup

public MyApiTests(BehavioralTestContextFixture<Startup> fixture)
{
    // Use WithDefault to automatically set return values for any method returning this type
    _myServiceMock = fixture.Mock<IMyService>()
        .WithDefault(() => myDefaultData);

    _httpClient = fixture.CreateClient();
}

Advanced Configuration

public class CustomFixture : BehavioralTestContextFixture<Startup>
{
    protected override Dictionary<string, object>? CommandLineArguments()
    {
        return new Dictionary<string, object>
        {
            { "ConnectionStrings:DefaultConnection", "test-connection-string" }
        };
    }
}

public class MyTests : IClassFixture<CustomFixture>
{
    // Your tests here
}

Key Components

ConfigurableWebApplicationFactory<TEntryPoint>

Extends Microsoft.AspNetCore.Mvc.Testing.WebApplicationFactory with:

• Service collection configuration
• Command-line argument injection
• Hosted service filtering

BehavioralTestContextFixture<TEntryPoint>

XUnit class fixture that:

• Shares a single WebApplicationFactory instance across tests
• Manages mock lifecycle with behavioral reset
• Provides easy client creation

Extension Methods

• Mock<T>(): Create and register mocks with the test services
• WithDefault<T, TReturn>(): Set default return values for mock methods
• ResetBehavioral(): Reset mocks including custom default value providers
• ReplaceAllWithSingleton<T>(): Replace all service registrations with a singleton

Dependencies

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

Credits

This library is based on the behavioral testing patterns from the BehavioralTesting repository by Jose-A-ProfessorFrink.

License

MIT

Contributing

Contributions are welcome! Please feel free to submit issues or pull requests. This project contains code to facilitate behavioral testing using Moq and the WebApplicationFactory.