Unit Testing Web Services - HttpContext

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 we

Answer 1

You might consider taking a dependency on System.Web.Abstractions.HttpContextBase instead of using HttpContext.Current. The System.Web.Abstractions assembly has a lot of common ASP.NET Http* classes already wrapped for you. They're used all over the ASP.NET MVC code. If you're using an IoC/DI framework, it's pretty easy to use. For example, in Ninject:

Bind<HttpContextBase>.ToMethod(x => new HttpContextWrapper(HttpContext.Current));

and then in your constructor...

public class SomeWebService
{
    private HttpContextBase _httpContext;

    public SomeWebService(HttpContextBase httpContext)
    {
        _httpContext = httpContext;
    }

    public void SomeOperationNeedingAuthorization()
    {
        IIdentity userIdentity = _httpContext.User.Identity;

        if (!userIdentity.IsAuthenticated)
            return;

        // Do something here...
    }
}

That's WAY oversimplified, but I hope you get the idea... As Aliostad mentioned, you can easily mock HttpContextBase using Rhino Mocks or Moq, etc. to test SomeOperationNeedingAuthorization.

Answer 2

I ended up putting a property on the web service:

Private mIdentity As System.Security.Principal.IIdentity
Public Property Identity() As System.Security.Principal.IIdentity
  Get
    If mIdentity Is Nothing Then mIdentity = HttpContext.Current.User.Identity
    Return mIdentity
  End Get
  Set(ByVal value As System.Security.Principal.IIdentity)
    mIdentity = value
  End Set
End Property

Then in my web service method:

<WebMethod()> _
Public Function GetProject(ByVal projectId As Int32) As String

  If Me.Identity.IsAuthenticated Then

    'code here

  End If

End Function

Then in my test (I'm using RhinoMocks):

Dim mockery As New MockRepository()
Dim mockIdentity As System.Security.Principal.IIdentity = mockery.DynamicMock(Of System.Security.Principal.IIdentity)()

Dim projectService As New TeamDynamix.Enterprise.Web.Next.ProjectService()
projectService.Identity = mockIdentity
mockIdentity.Stub(Function(i As System.Security.Principal.IIdentity) i.IsAuthenticated).Return(True)

Answer 3

If you are using mocking, you can wrap this logic in another class:

interface IAuthenticator
{
   bool IsAuthenticated();
}

and implement the real one:

class Authenticator : IAuthenticator
{
   bool IsAuthenticated()
   {
      return HttpContext.Current.User.Identity.IsAuthenticated;
   }
}

but in the test, create a mock and return true or false:

Mock<IAuthenticator> mock = new Mock<IAuthenticator>();
mock.Expect(x => x.IsAuthenticated()).Returns(true);

Answer 4

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.

Answer 5

Based on the solution above, I've implemented a wrapper class in the O2 Platform that allows the easy use of these mocking classes, for example this is how I can write and read from the HttpRequest.InputStream

var mockHttpContext = new API_Moq_HttpContext();
var httpContext = mockHttpContext.httpContext();
httpContext.request_Write("<html><body>".line());
httpContext.request_Write("   this is a web page".line());  
httpContext.request_Write("</body></html>"); 
return httpContext.request_Read();

see this blog post for more details: http://o2platform.wordpress.com/2011/04/05/mocking-httpcontext-httprequest-and-httpresponse-for-unittests-using-moq/