Writing automated tests for System.Web.HttpApplication

Question

I am currently using Moq to write automated tests for System.Web.HttpApplication in C#:

public FakeHttpApplication CreateBaseMocks()
{
    MockContext = new Mock<HttpContextBase>();
    MockRequest = new Mock<HttpRequestBase>();
    MockResponse = new Mock<HttpResponseBase>();
    MockSession = new Mock<HttpSessionStateBase>();
    MockServer = new Mock<HttpServerUtilityBase>();

    MockContext.Setup(ctx => ctx.Request).Returns(MockRequest.Object);
    MockContext.Setup(ctx => ctx.Response).Returns(MockResponse.Object);
    MockContext.Setup(ctx => ctx.Session).Returns(MockSession.Object);
    MockContext.Setup(ctx => ctx.Server).Returns(MockServer.Object);

    HttpContextBase = MockContext.Object;
    HttpRequestBase = MockRequest.Object;
    HttpResponseBase = MockResponse.Object;

    MockRequest.Setup(r => r.Headers).Returns(new NameValueCollection());
    return this;
}

public FakeHttpApplication SetupNormalRequestValues()
{
    //Context.User
    MockUser = new Mock<IPrincipal>();
    MockIdentity = new Mock<IIdentity>();
    MockContext.Setup(context => context.User).Returns(MockUser.Object);
    MockUser.Setup(context => context.Identity).Returns(MockIdentity.Object);

    //Request
    MockRequest.Setup(request => request.InputStream).Returns(new MemoryStream());

    //Response
    MockResponse.Setup(response => response.OutputStream).Returns(new MemoryStream());
    return this;
}

However, setting up the objects this way leaves a lot to be desired considering that most of the internal objects and properties remain null. Does anyone know of a better way to do this? I am looking for a way to instantiate a more lifelike HttpApplication object and don't mind a little complexity.

Answer 1

I am trying a mock that uses an Object List of return values as a queue. Every time my mock is supposed to return something, it first looks in the queue to see if I've queued anything, and if so, returns it.

Then I implemented an additional Queue method for my mock that I can call during test setup that just adds items to the List in the order I want them returned.

In this case, all of my return values will be ActionResults (we are using MVC) so I don't need to worry about return types, but you could use Reflection to implement something similar, where you return the first item in the queue that IsAssignableTo the return type of the method (I think that's the method in Reflection that you want . . . not sure).

You could also look at other mocking libraries that have this kind of "Record and Playback" functionality built-in. Moq is geared more towards being able to see if the right APIs are being called, etc., then about checking what the mocked interface returns. This article digresses into a discussion of philosophies about testing with mocks that explains this difference.

Answer 2

I would probably use selenium to drive the UI testing in the browser for ASP.NET. The UI test will be more brittle but they will give you an accurate indication if you application works correctly.

You will find that mocking the items you have shown will still need you to test that they function correctly through the UI. So you might as well push the testing up to integrated UI testing and drive them through a browser.