Mocking User.Identity.Name

One of the other issue you might encounter while unit testing your Controller is when you dealing with Identity. Consider the following action method.

public async Task<BarResponse> Foo(BarRequest user)
{
    if (ModelState.IsValid)
    {
        try
        {
            var userName = User.Identity.Name;
            // Do Task
            return new BarResponse{
                
            };
        }
        catch (Exception ex)
        {
            return new BarResponse { ErrorMessage = ex.Message};
        }
    }
    else
    {
        var errrorMessages = ModelState.Values.SelectMany(x => x.Errors.Select(c => c.ErrorMessage));
        return new BarResponse { ErrorMessage = string.Join(Environment.NewLine, errrorMessages), modelState = ModelState };
    }
}

One of the issues is how do one mock the User.Identity.Name. The trick lies in creating a Test instance of DefaultHttpContext and replace with Controller’s context. Let’s write an Unit Test for the above code.

var user = new ClaimsPrincipal(new ClaimsIdentity(new Claim[]
{
    new Claim(ClaimTypes.Name, "anuviswan"),
    
}, "mock"));
userController.ControllerContext.HttpContext = new DefaultHttpContext() { User = user };

Guess what, I spend atleast 5 hours for figuring out this. Some of the harder days in life.