单元测试MVC Controller时如何模拟FormsAuthentication

假如你的Controller里面包含如下代码

 public ActionResult Register(RegisterModel model)
        {
             ......................

                if (createStatus == MembershipCreateStatus.Success)
                {
                    FormsAuthentication.SetAuthCookie(userName, createPersistentCookie);
                    return RedirectToAction("Index", "Home");
                }           
            return View(model);
        }

在单元测试时候,红色那部分会抛异常。造成测试不便的原因是违反了SoC(separation of concern)原则。注册逻辑和登录逻辑混在一起。解决方案是将登录逻辑提取出来。

 public interface IAuthProvider
    {
        void SetAuthCookie(string userName, bool createPersistentCookie);
    }

    public class FormsAuthProvider : IAuthProvider
    {
      
        public void SetAuthCookie(string userName, bool createPersistentCookie)
        {
            FormsAuthentication.SetAuthCookie(userName, createPersistentCookie);
        }
    }
  public ActionResult Register(RegisterModel model)
        {
          
                if (createStatus == MembershipCreateStatus.Success)
                {
                    this.authProvider.SetAuthCookie(model.UserName, false /* createPersistentCookie */);
                    return RedirectToAction("Index", "Home");
                }
                else
                {
                    ModelState.AddModelError("", ErrorCodeToString(createStatus));
                }
            }

            // If we got this far, something failed, redisplay form
            return View(model);
        }

在测试时候用Moq去模拟FormsAuthentication，代码如下：

 public void RegisterTest()
        {
            Mock<IAuthProvider> mock = new Mock<IAuthProvider>();
            mock.Setup(m => m.SetAuthCookie("admin", false));

            var controller = new AccountController(mock.Object);         
            var result = (RedirectToRouteResult)controller.Register(model);
             Assert.AreEqual("Index", result.RouteValues["action"]);
          ;
        }

该方案来源于《Pro ASP.NET MVC 3 Framework》