Asp .Net Core单元测试模拟UserManager.CreateAsync并返回Identity结果

致力于 .Net Core 项目并创建了以下服务来跨页面共享通用方法。

namespace MyApp.Tests.Services
{
    public class UserServiceTest
    {
        [Fact]
        public async Task CreateUser_ShouldCreateUser()
        {
            var user = new UserResponse
            {
                Id = "111",
                Email = "[email protected] /cdn-cgi/l/email-protection",
                FirstName = "John",
                LastName = "Doe",
                CompanyName = "SomeCompany",
                PhoneNumber = "9123456789"
            };

            var appUser = new ApplicationUser
            {
                UserName = user.Email,
                Email = user.Email,
                FirstName = user.FirstName,
                LastName = user.LastName,
                CompanyName = user.CompanyName,
                PhoneNumber = user.PhoneNumber
            };

            var logger = Mock.Of<ILogger<UserService>>();
            var mockUserStore = new Mock<IUserStore<ApplicationUser>>();
            mockUserStore
                .Setup(x => x.CreateAsync(appUser, CancellationToken.None))
                .ReturnsAsync(IdentityResult.Success).Verifiable();

            // Tried this one as well but still getting null instead of IdentityResult
            // mockUserStore
            //     .Setup(x => x.CreateAsync(appUser, CancellationToken.None))
            //     .ReturnsAsync(new IdentityResultMock(true));

            var userManager = new UserManager<ApplicationUser>(mockUserStore.Object, null, null, null, null, null, null, null, null);
            var _userService = new UserService(userManager, logger);

            var result = await _userService.CreateUserInApp(user);

            Assert.True(result.Succeeded);
        }
    }

    public class IdentityResultMock : IdentityResult
    {
        public IdentityResultMock(bool succeeded) {
            base.Succeeded = succeeded;
         }
    }
}

还为此服务编写了单元测试用例，如下所示来测试 UserService

namespace MyApp.Tests.Services
{
    public class UserServiceTest
    {
        [Fact]
        public async Task CreateUser_ShouldCreateUser()
        {
            var user = new UserResponse
            {
                Id = "111",
                Email = "[email protected] /cdn-cgi/l/email-protection",
                FirstName = "John",
                LastName = "Doe",
                CompanyName = "SomeCompany",
                PhoneNumber = "9123456789"
            };

            var appUser = new ApplicationUser
            {
                UserName = user.Email,
                Email = user.Email,
                FirstName = user.FirstName,
                LastName = user.LastName,
                CompanyName = user.CompanyName,
                PhoneNumber = user.PhoneNumber
            };

            var logger = Mock.Of<ILogger<UserService>>();
            var mockUserStore = new Mock<IUserStore<ApplicationUser>>();
            mockUserStore
                .Setup(x => x.CreateAsync(appUser, CancellationToken.None))
                .ReturnsAsync(IdentityResult.Success).Verifiable(); ;

            var userManager = new UserManager<ApplicationUser>(mockUserStore.Object, null, null, null, null, null, null, null, null);
            var _userService = new UserService(userManager, logger);

            var result = await _userService.CreateUserInApp(user);

            Assert.True(result.Succeeded);
        }
    }
}

在用户服务中运行测试时

var createResult = await _userManager.CreateAsync(appUser);

createResult 由于此测试用例失败并出现空引用异常，我得到了空值。 如果我可以从模拟 CreateAsync 设置返回 IdentityResult，那么它会通过，但不确定我做错了什么。 也无法创建 IdentityResult 对象，因为“成功”受到保护并且无法显式赋值。 请帮忙。谢谢 ：）

我们需要看看构造函数内部发生了什么：

var userManager = new UserManager<ApplicationUser>(mockUserStore.Object, null, null, null, null, null, null, null, null);

但事实并非如此。如果您正在测试UserService在这里，那么你应该嘲笑的是UserManager而不是它的内部依赖IUserStore.

这是为什么？因为内部的UserManager可能会改变，然后你必须改变UserManager测试和UserService tests.

模拟创建UserManager就像你为IUserStore您会看到它是 UserStore 中的其他依赖项或完全超出单元测试范围的其他地方。

Edit 1

我想我已经找到你的问题了：

mockUserStore
    .Setup(x => x.CreateAsync(appUser, CancellationToken.None))
    .ReturnsAsync(IdentityResult.Success).Verifiable();

和调用

var result = await _userService.CreateUserInApp(user);

User 对象和 appUser 对象不相同，因此模拟框架不会返回预期值。

为了确保这是问题所在，请尝试使用

mockUserStore
    .Setup(x => x.CreateAsync(It.IsAny<ApplicationUser>(), It.IsAny<CancellationToken>()))
    .ReturnsAsync(IdentityResult.Success).Verifiable();