README.md

Kralizek.AutoFixture.Extensions.AspNetCore.WebApplicationFactory

This package is meant to provide an easy integration between AutoFixture and Microsoft.AspNetCore.Mvc.Testing to create integration tests for ASP.NET Core web applications.

Basic usage

You can use this extension by simply invoking the AddWebApplicationFactorySupport method on the IFixture instance at hand.

var fixture = new Fixture().AddWebApplicationFactorySupport<TestWebSite.Startup>();

var message = fixture.Create<string>();

var http = fixture.Create<HttpClient>();

var response = await http.PostAsync("/", new FormUrlEncodedContent(new Dictionary<string, string> { ["message"] = message }));

response.EnsureSuccessStatusCode();

var responseContent = await response.Content.ReadAsStringAsync();

Assert.That(responseContent, Is.EqualTo(message));

Usage with AutoData

Alternatively, you can use a customized version of the AutoData attribute to improve the readability of your unit tests.

[AttributeUsage(AttributeTargets.Method)]
public class TestAutoDataAttribute : AutoDataAttribute
{
    public TestAutoDataAttribute() : base(() => new Fixture().AddWebApplicationFactorySupport<TestWebSite.Startup>()) { }
}

[Test, TestAutoData]
public async Task Should_work_with_custom_auto_data_attribute(HttpClient http, string message)
{
    var response = await http.PostAsync("/", new FormUrlEncodedContent(new Dictionary<string, string> { ["message"] = message }));

    response.EnsureSuccessStatusCode();

    var responseContent = await response.Content.ReadAsStringAsync();

    Assert.That(responseContent, Is.EqualTo(message));
}

The HttpClient received as a parameter is already configured to target the in-memory instance of the web application under test.

Customizing the tested application

The WebApplicationFactory utility offered by Microsoft.AspNetCore.Mvc.Testing gives developers the possibility to customize the application to test.

A simple example is altering the service registrations to provide fakes instead of real dependencies.

This library allows the same workflow.

public interface IService
{
    string Echo(string message);
}

[AttributeUsage(AttributeTargets.Method)]
public class TestAutoDataAttribute : AutoDataAttribute
{
    public TestAutoDataAttribute() : base(CreateFixture) { }

    private static IFixture CreateFixture()
    {
        var fixture = new Fixture();

        fixture.Customize(new AutoMoqCustomization
        {
            ConfigureMembers = true,
            GenerateDelegates = true
        });

        fixture.Register<IService>(() => Mock.Of<MyTestServiceImpl>());

        fixture.AddWebApplicationFactorySupport<TestWebSite.Startup>(builder =>
        {
            builder.ConfigureServices(services =>
            {
                services.AddTransient<IService>(_ => fixture.Create<IService>());
            });
        });

        return fixture;
    }
}

[Test, TestAutoData]
public async Task Dependencies_are_overridden(HttpClient http, IService service)
{
    Mock.Get(service).Setup(p => p.Echo(It.IsAny<string>())).Returns((string str) => str);

    Assume.That(service, Is.InstanceOf<MyTestServiceImpl>());

    var response = await http.PostAsync("/", new FormUrlEncodedContent(new Dictionary<string, string> { ["message"] = message }));

    Mock.Get(service).Verify(p => p.Echo(It.IsAny<string>()), Times.Once());
}