public async Task RegisterTaskReturnsJsonWhenThereIsModelStateError()
{
const string modelStateErrorMessage = "modelStateErrorMessage";
var sut = new TaskApiController(null, null);
sut.AddModelStateErrorWithErrorMessage(modelStateErrorMessage);
var jsonResult = await sut.RegisterTask(new EventSignupViewModel()) as JsonResult;
var result = jsonResult.GetValueForProperty<List<string>>("errors");
Assert.IsType<JsonResult>(jsonResult);
Assert.IsType<List<string>>(result);
Assert.Equal(result.First(), modelStateErrorMessage);
}