public async Task GetSurveys_Always_ReturnsOk()
{
var mockRepository = Substitute.For <ISurveyRepository>();
mockRepository.GetSurveysAsync().Returns(RandomEntitiesGenerator.PredefinedSurveys);
var controller = new SurveyController(mockRepository);
var response = await controller.GetSurveysAsync();
response.Should().NotBeNull();
response.Result.Should().BeOfType <OkObjectResult>()
.Which.StatusCode.Should().Be((int)HttpStatusCode.OK);
var ok = response.Result as OkObjectResult;
ok.Value.Should().BeAssignableTo <IEnumerable <Survey> >();
ok.Value.Should().BeEquivalentTo(RandomEntitiesGenerator.PredefinedSurveys, opt => opt.IgnoringCyclicReferences());
await mockRepository.Received().GetSurveysAsync();
}