This project aims to emulate the functionality provided by IIS Integration in an ASP.NET Core project that uses Windows Authentication for the purposes of testing with ASP.NET Core's TestServer from Microsoft.AspNetCore.TestHost.

It provides real, authenticated Windows Auth capabilities - not just a mock of such. The WindowsIdentity of the WindowsPrincipal that will be signed into your application can use all normal behaviors, including .Impersonate().

Visit Nuget.org to pull this library into your project as a dependency.

There are two main ways to use this library:

1. Use the provided TestServer fixture that will add the required services for you.
2. Use your own fixture and build a WebHostBuilder and TestServer yourself.

This project is designed to be used with xunit, but has no hard dependencies on it. The below example assumes xunit usage, but could easily be adapted for other test frameworks.

In your test project:

public class MyProjectServerFixture : WindowsAuthServerFixture<Startup>
{
    // Override members as desired. Likely culprits are:

    protected override string ApplicationName => "MyCompany.MyProject.Web";

    // Path to the web project, relative to the working directory of the running test assembly. 
    // Default value (seen below) assumes test and web project live side-by-side.
    // If projects are nested differently (e.g. separate 'src' and 'test' directories), modify as needed.
    protected override string ContentRoot => $"../../../../{ApplicationName}";
}

For more info about overridable members of WindowsAuthServerFixture, view this project's source code.

If the provided fixture doesn't fit your needs, or you already have your own fixture for a TestServer/WebHostBuilder, you can simply add the needed services yourself:

var builder = new WebHostBuilder()
    // Your method calls go here...
    .ConfigureServices(services =>
    {
        services.AddWindowsAuthenticationForTesting();

        // ONLY IF AuthenticationMiddleware (UseAuthentication) isn't normally part of your pipeline:
        services.AddTransient<IStartupFilter, AddAuthenticationStartupFilter>();
    });

You would then create a test fixture (or equivalent for your preferred test framework) that would expose a TestServer created from this WebHostBuilder.

Then, in an xunit test:

public class MyTests : IClassFixture<MyProjectServerFixture>
{
    private readonly TestServer _server;

    public MyTests(MyProjectServerFixture fixture)
    {
        _server = fixture.Server;
    }

    [Fact]
    public async Task MyTest() 
    {
        HttpClient client;
        // Choose one:
        client = _server.ClientForAnonymous();
        client = _server.ClientForCurrentUser(); // Effectively: UseDefaultCredentials = true
        client = _server.ClientForUser(new NetworkCredential("userName", "password", "DOMAIN"));

        // Make requests against the HttpClient. The requests will be appropriately authenticated when they are handled by your web application, despite not running with IIS.
    }
}

• If requests aren't being authenticated, ensure that the standard AuthenticationMiddleware is part of your request pipeline. Typically, this middleware is added by calling app.UseAuthentication() in the Configure method of Startup.cs. This middleware isn't strictly required when using IIS integration with Windows auth enabled and anonymous auth disabled, but it is required for this library. There is an overridable property, AddAuthenticationMiddleware, on WindowsAuthServerFixture that if overridden to true will add the middleware on your behalf.
• This library sets its authentication handler as the default authentication scheme, overriding any other scheme configured in your Startup.cs. If this is not desired, check out WindowsAuthServiceCollectionExtensions.cs for how to add in the required services yourself in a different manner.