单元测试模拟 ControllerContext HttpContext 没有为类型“Microsoft.AspNetCore.Mvc.View...ITempDataDictionaryFactory”注册服务

Question

In my test project i am using xUnit with Moq.

now i want to unit test these piece of code in the controller:

[HttpGet]
[AllowAnonymous]
public async Task<IActionResult> Login(string returnUrl = null)
{
    await HttpContext.SignOutAsync(IdentityConstants.ExternalScheme);

    ViewData["ReturnUrl"] = returnUrl;
    return View();
}

As you see it uses the SignOutAsync of the HttpContext .

I tried so many solution such as ASP.NET MVC - Unit testing, mocking HttpContext without using any mock framework but didn't work for me, since i dont have access to the HttpRequestBase

Using Moq, i am trying to mock this HttpContext , so i tried this:

public static Mock<HttpContext> GenerateFakeHttpContext()
{
   var mockHttpContext = new Mock<HttpContext>();
   var authServiceMock = new Mock<IAuthenticationService>();
   authServiceMock.Setup(_ => _.SignOutAsync(
                                   It.IsAny<HttpContext>(), 
                                   It.IsAny<string>(), 
                                   It.IsAny<AuthenticationProperties>()))
       .Returns(Task.FromResult((object)null));

   var serviceProviderMock = new Mock<IServiceProvider>();

   serviceProviderMock.Setup(_ => _.GetService(typeof(IAuthenticationService)))
           .Returns(authServiceMock.Object);

   mockHttpContext.Setup(x => x.RequestServices)
           .Returns(serviceProviderMock.Object);

   return mockHttpContext;
}

inspired from this question: MSTest: Unit Testing HttpContext.SignoutAsync for the logout , after a multiple research.

The test method is like this:

public async Task Login_ShouldSignOutToClearCoockies_WhenReturnUrlIsNullOrNotNull()
{
    //Arrange
    _sutAccountController
    .ControllerContext.HttpContext = TestsHelper.GenerateFakeHttpContext().Object;

    //Act
    var result = await _sutAccountController.Login(null);

    //Assert
    result.Should().NotBeNull();
}

but in runtime i get this exception:

   Duration: 367 ms

  Message: 
System.InvalidOperationException : No service for type 'Microsoft.AspNetCore.Mvc.ViewFeatures.ITempDataDictionaryFactory' has been registered.

  Stack Trace: 
ServiceProviderServiceExtensions.GetRequiredService(IServiceProvider provider, Type serviceType)
ServiceProviderServiceExtensions.GetRequiredService[T](IServiceProvider provider)
Controller.get_TempData()
Controller.View(String viewName, Object model)
Controller.View(String viewName)
Controller.View()
AccountController.Login(String returnUrl) line 38
AccountControllerTests.Login_ShouldSignOutToClearCoockies_WhenReturnUrlIsNullOrNotNull() line 46
--- End of stack trace from previous location ---

if there's a better way to mock the HttpContext .

Thanks.

Answer 1

i finally, found a solution by mocking the controller TempData

Source: Mocking a TempData in ASP.NET Core in MSTest

var tempData = new Microsoft.AspNetCore.Mvc.ViewFeatures
.TempDataDictionary(httpContext, Mock.Of<Microsoft.AspNetCore.Mvc.ViewFeatures.ITempDataProvider>());
tempData["ReturnUrl"] = "";

_sutController.ControllerContext.HttpContext = httpContext;
_sutController.TempData = tempData