单元测试ASP.NET MVC5应用程序

Question

我通过添加一个新属性来扩展ApplicationUser类(如教程中所示, 使用Facebook和Google OAuth2和OpenID登录创建一个ASP.NET MVC 5应用程序(C#))

public class ApplicationUser : IdentityUser
{
    public DateTime BirthDate { get; set; }
}

现在我想创建一个单元测试来验证我的AccountController是否正确保存了BirthDate.

我创建了一个名为TestUserStore的内存用户存储

[TestMethod]
public void Register()
{
    // Arrange
    var userManager = new UserManager<ApplicationUser>(new TestUserStore<ApplicationUser>());
    var controller = new AccountController(userManager);

    // This will setup a fake HttpContext using Moq
    controller.SetFakeControllerContext();

    // Act
    var result =
        controller.Register(new RegisterViewModel
        {
            BirthDate = TestBirthDate,
            UserName = TestUser,
            Password = TestUserPassword,
            ConfirmPassword = TestUserPassword
        }).Result;

    // Assert
    Assert.IsNotNull(result);

    var addedUser = userManager.FindByName(TestUser);
    Assert.IsNotNull(addedUser);
    Assert.AreEqual(TestBirthDate, addedUser.BirthDate);
}

controller.Register方法是由MVC5生成的样板代码,但为了参考目的,我在这里包含它.

// POST: /Account/Register
[HttpPost]
[AllowAnonymous]
[ValidateAntiForgeryToken]
public async Task<ActionResult> Register(RegisterViewModel model)
{
    if (ModelState.IsValid)
    {
        var user = new ApplicationUser() { UserName = model.UserName, BirthDate = model.BirthDate };
        var result = await UserManager.CreateAsync(user, model.Password);
        if (result.Succeeded)
        {
            await SignInAsync(user, isPersistent: false);
            return RedirectToAction("Index", "Home");
        }
        else
        {
            AddErrors(result);
        }
    }

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

当我调用Register时,它会调用SignInAsync,这就是发生故障的地方.

private async Task SignInAsync(ApplicationUser user, bool isPersistent)
{
    AuthenticationManager.SignOut(DefaultAuthenticationTypes.ExternalCookie);
    var identity = await UserManager.CreateIdentityAsync(user, DefaultAuthenticationTypes.ApplicationCookie);
    AuthenticationManager.SignIn(new AuthenticationProperties() { IsPersistent = isPersistent }, identity);
}

在最低层,样板代码包括这个花絮

private IAuthenticationManager AuthenticationManager
{
    get
    {
        return HttpContext.GetOwinContext().Authentication;
    }
}

这是问题的根源发生的地方.这个对GetOwinContext的调用是一个扩展方法,我无法模拟,我不能用存根替换(除非我当然更改了样板代码).

当我运行此测试时,我得到一个例外

Test method MVCLabMigration.Tests.Controllers.AccountControllerTest.Register threw exception: 
System.AggregateException: One or more errors occurred. ---> System.NullReferenceException: Object reference not set to an instance of an object.
at System.Web.HttpContextBaseExtensions.GetOwinEnvironment(HttpContextBase context)
at System.Web.HttpContextBaseExtensions.GetOwinContext(HttpContextBase context)
at MVCLabMigration.Controllers.AccountController.get_AuthenticationManager() in AccountController.cs: line 330
at MVCLabMigration.Controllers.AccountController.<SignInAsync>d__40.MoveNext() in AccountController.cs: line 336

在以前的版本中,ASP.NET MVC团队非常努力地使代码可以测试.从表面上看,现在测试AccountController并不容易.我有一些选择.

我可以

1. 修改锅炉板代码,使其不调用扩展方法并在该级别处理此问题

2. 设置OWin管道以进行测试

3. 避免编写需要AuthN/AuthZ基础设施的测试代码(不是合理的选择)

我不确定哪条路更好.任何人都可以解决这个问题.我的问题归结为哪个是最好的策略.

注意:是的,我知道我不需要测试我没写过的代码.UserManager基础设施提供MVC5就是这样一个基础设施但是如果我想编写验证我对ApplicationUser的修改的测试或验证依赖于用户角色的行为的代码那么我必须使用UserManager进行测试.

Answer 1

我正在回答我自己的问题,所以如果你认为这是一个很好的答案,我可以从社区得到一个感觉.

步骤1:修改生成的AccountController,使用支持字段为AuthenticationManager提供属性设置器.

// Add this private variable
private IAuthenticationManager _authnManager;

// Modified this from private to public and add the setter
public IAuthenticationManager AuthenticationManager
{
    get
    {
        if (_authnManager == null)
            _authnManager = HttpContext.GetOwinContext().Authentication;
        return _authnManager;
    }
    set { _authnManager = value; }
}

步骤2: 修改单元测试以为Microsoft.OWin.IAuthenticationManager接口添加模拟

[TestMethod]
public void Register()
{
    // Arrange
    var userManager = new UserManager<ApplicationUser>(new TestUserStore<ApplicationUser>());
    var controller = new AccountController(userManager);
    controller.SetFakeControllerContext();

    // Modify the test to setup a mock IAuthenticationManager
    var mockAuthenticationManager = new Mock<IAuthenticationManager>();
    mockAuthenticationManager.Setup(am => am.SignOut());
    mockAuthenticationManager.Setup(am => am.SignIn());

    // Add it to the controller - this is why you have to make a public setter
    controller.AuthenticationManager = mockAuthenticationManager.Object;

    // Act
    var result =
        controller.Register(new RegisterViewModel
        {
            BirthDate = TestBirthDate,
            UserName = TestUser,
            Password = TestUserPassword,
            ConfirmPassword = TestUserPassword
        }).Result;

    // Assert
    Assert.IsNotNull(result);

    var addedUser = userManager.FindByName(TestUser);
    Assert.IsNotNull(addedUser);
    Assert.AreEqual(TestBirthDate, addedUser.BirthDate);
}

现在测试通过.

好主意？馊主意？

Answer 2

我的需求是相似的，但我意识到我不想对我的 AccountController 进行纯单元测试。相反，我想在尽可能接近其自然栖息地的环境中对其进行测试（如果需要，可以进行集成测试）。所以我不想模拟周围的物体，而是使用真实的物体，尽可能少地使用我自己的代码。

HttpContextBaseExtensions.GetOwinContext 方法也妨碍了我，所以我对 Blisco 的提示非常满意。现在我的解决方案最重要的部分如下所示：

/// <summary> Set up an account controller with just enough context to work through the tests. </summary>
/// <param name="userManager"> The user manager to be used </param>
/// <returns>A new account controller</returns>
private static AccountController SetupAccountController(ApplicationUserManager userManager)
{
    AccountController controller = new AccountController(userManager);
    Uri url = new Uri("https://localhost/Account/ForgotPassword"); // the real string appears to be irrelevant
    RouteData routeData = new RouteData();

    HttpRequest httpRequest = new HttpRequest("", url.AbsoluteUri, "");
    HttpResponse httpResponse = new HttpResponse(null);
    HttpContext httpContext = new HttpContext(httpRequest, httpResponse);
    Dictionary<string, object> owinEnvironment = new Dictionary<string, object>()
    {
        {"owin.RequestBody", null}
    };
    httpContext.Items.Add("owin.Environment", owinEnvironment);
    HttpContextWrapper contextWrapper = new HttpContextWrapper(httpContext);

    ControllerContext controllerContext = new ControllerContext(contextWrapper, routeData, controller);
    controller.ControllerContext = controllerContext;
    controller.Url = new UrlHelper(new RequestContext(contextWrapper, routeData));
    // We have not found out how to set up this UrlHelper so that we get a real callbackUrl in AccountController.ForgotPassword.

    return controller;
}

我还没有成功地让一切正常工作（特别是，我无法让 UrlHelper 在 ForgotPassword 方法中生成正确的 URL），但现在我的大部分需求都得到了满足。