rhino-mocks | Dynamic Mocking Framework for .NET | Mock library

I have read this article, but in your case, I think that doing such a thing would be an overkill..

Since GetOwinContext() return an interface all you have to do is to separate this call from the method, doing such a thing has 2 problems:

1. The method under test(OnActionExecuting() is owned by an attribute class.
2. GetOwinContext() is a static method.

The best 2 solutions that I can offer you is:

1. Use code waving tool like MsFakes, Typemock Isolator and etc, instead of proxy based tool like RhinoMocks.
2. Extract GetOwinContext() to a virtual method and then use PartialMock technique(This technique is usually in use for abstract classes):

Let's say that MyCustonAttributte is your attribute:

This sounds an integration test to me. Anyways, forget RhinoMock in this case because there's no other way to do it but to create your own test suite here. In our case we actually used HttpClient to call the controller/api and pass the url and argument needed for action and anticipate the result for validation.