public When_ProviderVenue_Add_Venue_Does_Not_Exist() { _providerVenueService = Substitute.For <IProviderVenueService>(); _providerVenueService.IsValidPostcodeAsync("CV1 2WT").Returns((true, "CV1 2WT")); _providerVenueService.GetVenueAsync(1, "CV1 2WT").ReturnsNull(); _providerVenueService.CreateVenueAsync(Arg.Any <AddProviderVenueViewModel>()).Returns(1); var providerVenueController = new ProviderVenueController(_providerVenueService); var controllerWithClaims = new ClaimsBuilder <ProviderVenueController>(providerVenueController) .AddUserName("username") .AddEmail("*****@*****.**") .Build(); var viewModel = new AddProviderVenueViewModel { ProviderId = 1, Postcode = "CV1 2WT" }; _result = controllerWithClaims.CreateVenueAsync(viewModel).GetAwaiter().GetResult(); }