Question

I want to write unit tests for a web service. I create my test project, reference my web project (not service reference, assembly reference), then write some code to test the web services – they work fine. However, there are some services which make sure the user is logged in to the web application by using HttpContext.Current.User.Identity.IsAuthenticated.

In the context of the tests, there is no such thing as HttpContext, so the tests always fail. How should these kinds of web services be unit tested?

Answer 1

Here is a related discussion.

I stopped referencing HttpContext.Current directly. and use this class instead:

public class HttpContextFactory
{
    private static HttpContextBase m_context;
    public static HttpContextBase Current
    {
        get
        {
            if (m_context != null)
                return m_context;

            if (HttpContext.Current == null)
                throw new InvalidOperationException("HttpContext not available");

            return new HttpContextWrapper(HttpContext.Current);
        }
    }

    public static void SetCurrentContext(HttpContextBase context)
    {
        m_context = context;
    }
}

and use HttpContextFactory.Current instead of HttpContext.Current in our code.

Then you write this in your test:

        HttpContextFactory.SetCurrentContext(GetMockedHttpContext());

where GetMockedHttpContext() is from here and looks like this:

    private System.Web.HttpContextBase GetMockedHttpContext()
    {
        var context = new Mock<HttpContextBase>();
        var request = new Mock<HttpRequestBase>();
        var response = new Mock<HttpResponseBase>();
        var session = new Mock<HttpSessionStateBase>();
        var server = new Mock<HttpServerUtilityBase>();
        var user = new Mock<IPrincipal>();     
        var identity = new Mock<IIdentity>();

        context.Setup(ctx => ctx.Request).Returns(request.Object);
        context.Setup(ctx => ctx.Response).Returns(response.Object);
        context.Setup(ctx => ctx.Session).Returns(session.Object);
        context.Setup(ctx => ctx.Server).Returns(server.Object);
        context.Setup(ctx => ctx.User).Returns(user.Object);
        user.Setup(x => x.Identity).Returns(identity.Object);
        identity.Setup(id => id.IsAuthenticated).Returns(true);
        identity.Setup(id => id.Name).Returns("test");

        return context.Object;
    }

It uses a mocking framework called moq

In your test project you have to add a reference to System.Web and System.Web.Abstractions, where HttpContextBase is defined.