Problem unit testing async calls

[Tony Wright]

Hi all,

I have been trying to unit test an async call in an MVC app and I can't
quite get it right.

The application is an MVC app written in dot net.

I am using xUnit to test the method, and Fluent Assertions to more
naturally describe the expected outcome (BDD).

The test case is a Quiz application.

Here is the test:

 [Fact(DisplayName = "Calling the NextQuizQuestion api returns a question")]
 public async void CallingNextQuizQuestionGetsAResult()
 {
     //Arrange
     string userId = "t...@blah.com";
     var triviaRepository = Mock.Create<TriviaRepository>();
     Mock.Arrange(() => triviaRepository.NextQuestionAsync(userId))
         .Returns(() =>
             Task.FromResult(
                 new TriviaQuestion
                 {
                     Title = "When was .NET first released?",
                     Options = (new TriviaOption[]
                     {
                         new TriviaOption {Title = "2000", IsCorrect = false},
                         new TriviaOption {Title = "2001", IsCorrect = false},
                         new TriviaOption {Title = "2002", IsCorrect = true},
                         new TriviaOption {Title = "2003", IsCorrect = false}
                     }).ToList()
                 })
                 ).MustBeCalled();

     //Act
     UnitOfWork uow = new UnitOfWork(triviaRepository);
     TriviaController controller = new TriviaController(uow);

     var taskResult = await controller.Get();

     var result = Task.FromResult(taskResult);

     //Assert
     Assert.IsType<OkResult>(result.Result);

 }

The controller method that I am instantiating is:

[ResponseType(typeof(TriviaQuestion))]public async Task<IHttpActionResult> Get()
{
    var userId = User.Identity.Name;

    TriviaQuestion nextQuestion = await
unitOfWork.TriviaRepository.NextQuestionAsync(userId);

    if (nextQuestion == null)
    {
        return this.NotFound();
    }

    return this.Ok(nextQuestion);
}


The test crashes on the line

var taskResult = await controller.Get();

due to a timeout.

The issue here I believe is that the test is single threaded and it never
returns from the call because it doesn't have a synchronisation context to
return to.

Does anyone know how I can get this test to work?

Regards,
Tony