Testing controller Action that uses User.Identity.Name

Question

Hello, I have an action that relies on User.Identity.Name to get the username of the current user to get a list of his orders:

public ActionResult XLineas()
    {
        ViewData["Filtre"] = _options.Filtre;
        ViewData["NomesPendents"] = _options.NomesPendents;
        return View(_repository.ObteLiniesPedido(User.Identity.Name,_options.Filtre,_options.NomesPendents));
    }

Now I'm trying to write unit tests for this, but I get stuck on how to provide a Mock for User.Identity.Name. If I run my test as I have it (without mock for User...), I get a Null.. exception.

Which is the correct approach for this? I'm thinking that my Action code is not good for unit testing.

Answer 1

A better way of doing this would be to pass a string argument userName (or an IPrincipal argument user, if you need more information than just the name) to the ActionMethod, which you "inject" in a normal request using an ActionFilterAttribute. When you test it, you just supply your own mock object, as the action filter's code will not run (in most cases - there are ways to, if you specifically want to...)

Kazi Manzur Rashid describes this in detail under point 7 in an excellent blog post.