如何在 .Net Core 测试中模拟 UserManager？

Question

我有以下代码。我试图为创建用户运行一个测试用例。以下是我到目前为止所尝试的。

public class CreateUserCommandHandlerTest
{
    private Mock<UserManager<ApplicationUser>> _userManager;
    private CreateUserCommandHandler _systemUnderTest;

    public CreateUserCommandHandlerTest()
    {
        _userManager = MockUserManager.GetUserManager<ApplicationUser>();
        var user = new ApplicationUser() { UserName = "ancon1", Email = "ancon@mail.com", RoleType = RoleTypes.Anonymous };
        _userManager
            .Setup(u => u.CreateAsync(user, "ancon2")).ReturnsAsync(IdentityResult.Success);
        _systemUnderTest = new CreateUserCommandHandler(_userManager.Object);
    }

    [Fact]
    public async void Handle_GivenValidInput_ReturnsCreatedResponse()
    {
        var command = new CreateUserCommand { Username = "ancon1", Email = "ancon@mail.com", Password = "ancon2", RoleType = RoleTypes.Anonymous };
        var result = await _systemUnderTest.Handle(command, default(CancellationToken));
        Assert.NotNull(result);
        Assert.IsType<Application.Commands.CreatedResponse>(result);
    }
}

我的用户管理员在这里：

public static class MockUserManager
{
    public static Mock<UserManager<TUser>> GetUserManager<TUser>()
        where TUser : class
    {
        var store = new Mock<IUserStore<TUser>>();
        var passwordHasher = new Mock<IPasswordHasher<TUser>>();
        IList<IUserValidator<TUser>> userValidators = new List<IUserValidator<TUser>>
        {
            new UserValidator<TUser>()
        };
        IList<IPasswordValidator<TUser>> passwordValidators = new List<IPasswordValidator<TUser>>
        {
            new PasswordValidator<TUser>()
        };
        userValidators.Add(new UserValidator<TUser>());
        passwordValidators.Add(new PasswordValidator<TUser>());
        var userManager = new Mock<UserManager<TUser>>(store.Object, null, passwordHasher.Object, userValidators, passwordValidators, null, null, null, null);
        return userManager;
    }
}

我的命令处理程序是这样的：

 public class CreateUserCommandHandler : IRequestHandler<CreateUserCommand, BaseCommandResponse>
{
    private readonly UserManager<ApplicationUser> _userManager;

    public CreateUserCommandHandler(UserManager<ApplicationUser> userManager)
    {
        _userManager = userManager;
    }

    public async Task<BaseCommandResponse> Handle(CreateUserCommand createUserCommand, CancellationToken cancellationToken)
    {
        var user = new ApplicationUser { UserName = createUserCommand.Username, Email = createUserCommand.Email, RoleType = createUserCommand.RoleType };
        var result = await _userManager.CreateAsync(user, createUserCommand.Password);
        if (result.Succeeded)
        {
            return new CreatedResponse();
        }

        ErrorResponse errorResponse = new ErrorResponse(result.Errors.Select(e => e.Description).First());

        return errorResponse;
    }
}

当我运行我的测试时，它失败并说对象引用未设置为对象的瞬间。

我在这里做错了什么？？

Answer 1

我知道这已经有几个月了，但我一直在回到这个线程。我将在这个主题上扩展我自己的答案，因为仅仅指向 Haok 的 GitHub 示例就像是在说：“读一本书”，因为它很大。它没有指出问题以及您需要做什么。您需要隔离一个 Mock 对象，但不仅如此，您还需要“设置”“CreateAsync”的方法。所以让我们把它分成三个部分：

1. 如果您使用 MOQ 或类似框架来模拟创建 UserManager，则需要 MOCK。
2. 您需要设置希望从中获取结果的 UserManager 方法。
3. （可选）您希望从模拟的 Entity Framework Core 2.1 或类似版本中注入一些通用列表，以便您可以实际看到 IDentity 用户列表实际增加或减少。不仅是 UserManager 成功了，没有别的了

假设我有一个返回模拟用户管理器的辅助方法。与 Haok 代码略有不同：

public static Mock<UserManager<TUser>> MockUserManager<TUser>(List<TUser> ls) where TUser : class
{
    var store = new Mock<IUserStore<TUser>>();
    var mgr = new Mock<UserManager<TUser>>(store.Object, null, null, null, null, null, null, null, null);
    mgr.Object.UserValidators.Add(new UserValidator<TUser>());
    mgr.Object.PasswordValidators.Add(new PasswordValidator<TUser>());

    mgr.Setup(x => x.DeleteAsync(It.IsAny<TUser>())).ReturnsAsync(IdentityResult.Success);
    mgr.Setup(x => x.CreateAsync(It.IsAny<TUser>(), It.IsAny<string>())).ReturnsAsync(IdentityResult.Success).Callback<TUser, string>((x, y) => ls.Add(x));
    mgr.Setup(x => x.UpdateAsync(It.IsAny<TUser>())).ReturnsAsync(IdentityResult.Success);

    return mgr;
}

对此的关键是我正在注入一个通用的“TUser”，这也是我将要测试的内容以及注入此列表的内容。类似于我的示例：

 private List<ApplicationUser> _users = new List<ApplicationUser>
 {
      new ApplicationUser("User1", "user1@bv.com") { Id = 1 },
      new ApplicationUser("User2", "user2@bv.com") { Id = 2 }
 };
    
 ...

 private _userManager = MockUserManager<ApplicationUser>(_users).Object; 

最后我正在使用类似于我要测试的这个实现的存储库来测试一个模式：

 public async Task<int> CreateUser(ApplicationUser user, string password) => (await _userManager.CreateAsync(user, password)).Succeeded ? user.Id : -1;

我是这样测试的：

 [Fact]
 public async Task CreateAUser()
 {
      var newUser = new ApplicationUser("NewUser", "New@test.com");
      var password = "P@ssw0rd!";

      var result = await CreateUser(newUser, password);

      Assert.Equal(3, _users.Count);
  }

我所做的关键在于，我不仅“设置”了 CreateAsync，而且还提供了一个回调，因此我实际上可以看到我注入的列表增加了。希望这对某人有所帮助。

Answer 2

aspnet/Identity 是开源的，所以你可以做的是看看他们如何自己模拟它。

他们是这样做的：MockHelpers.cs

测试用户管理器

public static UserManager<TUser> TestUserManager<TUser>(IUserStore<TUser> store = null) where TUser : class
{
    store = store ?? new Mock<IUserStore<TUser>>().Object;
    var options = new Mock<IOptions<IdentityOptions>>();
    var idOptions = new IdentityOptions();
    idOptions.Lockout.AllowedForNewUsers = false;
    options.Setup(o => o.Value).Returns(idOptions);
    var userValidators = new List<IUserValidator<TUser>>();
    var validator = new Mock<IUserValidator<TUser>>();
    userValidators.Add(validator.Object);
    var pwdValidators = new List<PasswordValidator<TUser>>();
    pwdValidators.Add(new PasswordValidator<TUser>());
    var userManager = new UserManager<TUser>(store, options.Object, new PasswordHasher<TUser>(),
        userValidators, pwdValidators, new UpperInvariantLookupNormalizer(),
        new IdentityErrorDescriber(), null,
        new Mock<ILogger<UserManager<TUser>>>().Object);
    validator.Setup(v => v.ValidateAsync(userManager, It.IsAny<TUser>()))
        .Returns(Task.FromResult(IdentityResult.Success)).Verifiable();
    return userManager;
}

Answer 3

在 .NetCore 2.2 中，您必须稍有不同。将其视为对@Nick Chapsas 答案的更新。

首先，您必须使用 IUserPasswordStore 而不是 IUserStore。 IUserPasswordStore 继承了 IUserStore，但 UserManager 想要获取 IUserPasswordStore。否则，有些事情是行不通的。

如果你想测试 UserManager 的真实行为（例如 CreateUserAsync），你可以使用 UserValidator 和 PasswordValidator 的真实实现。您可能只想确保您的方法对 CreateUser 错误做出应有的反应。

这是我更新的示例：

UserManager<TUser> CreateUserManager() where TUser : class
{
    Mock<IUserPasswordStore<TUser>> userPasswordStore = new Mock<IUserPasswordStore<TUser>>();
    userPasswordStore.Setup(s => s.CreateAsync(It.IsAny<TUser>(), It.IsAny<CancellationToken>()))
        .Returns(Task.FromResult(IdentityResult.Success));

    var options = new Mock<IOptions<IdentityOptions>>();
    var idOptions = new IdentityOptions();

    //this should be keep in sync with settings in ConfigureIdentity in WebApi -> Startup.cs
    idOptions.Lockout.AllowedForNewUsers = false;
    idOptions.Password.RequireDigit = true;
    idOptions.Password.RequireLowercase = true;
    idOptions.Password.RequireNonAlphanumeric = true;
    idOptions.Password.RequireUppercase = true;
    idOptions.Password.RequiredLength = 8;
    idOptions.Password.RequiredUniqueChars = 1;

    idOptions.SignIn.RequireConfirmedEmail = false;

    // Lockout settings.
    idOptions.Lockout.DefaultLockoutTimeSpan = TimeSpan.FromMinutes(5);
    idOptions.Lockout.MaxFailedAccessAttempts = 5;
    idOptions.Lockout.AllowedForNewUsers = true;


    options.Setup(o => o.Value).Returns(idOptions);
    var userValidators = new List<IUserValidator<TUser>>();
    UserValidator<TUser> validator = new UserValidator<TUser>();
    userValidators.Add(validator);

    var passValidator = new PasswordValidator<TUser>();
    var pwdValidators = new List<IPasswordValidator<TUser>>();
    pwdValidators.Add(passValidator);
    var userManager = new UserManager<TUser>(userPasswordStore.Object, options.Object, new PasswordHasher<TUser>(),
        userValidators, pwdValidators, new UpperInvariantLookupNormalizer(),
        new IdentityErrorDescriber(), null,
        new Mock<ILogger<UserManager<TUser>>>().Object);

    return userManager;
}

请注意，如果您想从 UserManager 测试 CreateAsync，则 UserPasswordStore 有一个方法 (CreateAsync) 应该被模拟。

密码和锁定设置取自我的项目。它们应该与您的设置保持同步，以便您可以测试真实的东西。

当然你不测试例如PasswordValidator，但是你可以测试你的方法，例如：

//Part of user service
public async Task<IdentityResult> Register(UserDto data)
{
    SystemUser user = ConvertDtoToUser(data);
    IdentityResult result = userManager.CreateAsync(user, data.Password);

    //some more code that is dependent on the result
}