如何测试返回 Ok(new { token = tokenStr }); 的函数

Question

这是我的控制器类的函数，我想测试它，但我不知道为什么检查 OkObject 为空。我需要一些建议和解决这个问题的方法：

[HttpGet]
        public async Task<IActionResult> LoginAsync(string phoneNumber, string pass)
        {
            User login = new User();
            login.Phone = phoneNumber;
            login.Password = pass;
            IActionResult response = Unauthorized();

            var user = await _loginService.AuthenticateUserAsync(login);
            if(user != null)
            {
                var tokenStr = _loginService.GenerateJWT(user);
                response = Ok(new { token = tokenStr });
            }
            return response;
        }

我的测试功能是：

[Fact]
        public async Task LoginAsync_ReturnOk()
        {
            var mock = new Mock<ILoginService>();

            var controller = new LoginController(mock.Object);

            var phone = "0123456789";
            var pass = "abc123";
            var okResult = await controller.LoginAsync(phone, pass);
            Assert.IsType<OkObjectResult>(okResult as OkObjectResult);


        }

我真的需要你的帮助。

Answer 1

测试失败，因为模拟的依赖项尚未配置为当前测试用例的预期行为。

指定测试用例的被测主体需要

//...

 if(user != null)

//...

为true，但未为测试用例配置_loginService

//...

var user = await _loginService.AuthenticateUserAsync(login);

//...

这意味着被测主体将返回UnauthorizedResult

这将导致 okResult as OkObjectResult 为 null

需要安排测试，以便测试用例在执行时将按预期运行

[Fact]
public async Task LoginAsync_Should_Return_Ok() {
    // Arrange
    var mock = new Mock<ILoginService>();

    var user = new UserResult(); //Or what ever the actual user type is
    
    mock.Setup(_ => _.AuthenticateUserAsync(It.IsAny<User>()))
        .ReturnsAsync(user);

    string tokenStr = "some token value";

    mock.Setup(_ => _.GenerateJWT(user)).Returns(tokenStr);

    LoginController controller = new LoginController(mock.Object);

    string phone = "0123456789";
    string pass = "abc123";

    //Act
    IActionResult response = await controller.LoginAsync(phone, pass);

    //Assert
    OkObjectResult okResult = Assert.IsType<OkObjectResult>(response);
    
    //Optional: additional assertions for this test case
    dynamic value = okResult.Value;
    Assert.NotNull(value);

    string token = (string)value.token;
    Assert.Equal(token, tokenStr);
}

并且因为有还有未经授权的响应的可能结果，这里是另一个测试用例来覆盖该控制器操作

[Fact]
public async Task LoginAsync_Should_Return_Unauthorized() {
    //Arrange
    var mock = new Mock<ILoginService>();
    mock.Setup(_ => _.AuthenticateUserAsync(It.IsAny<User>()))
        .ReturnsAsync((UserResult)null); //Or what ever the actual user type is

    LoginController controller = new LoginController(mock.Object);

    string phone = "0123456789";
    string pass = "abc123";

    //Act
    IActionResult response = await controller.LoginAsync(phone, pass);

    //Assert
    Assert.IsType<UnauthorizedResult>(response);
}