public IActionResult CustomerPhoneNumbers(Guid guid) { Customer customer; try { //customer = PhoneService.FindCustomerByGuid(guid); //Moved to controller to enable testing with Moq List <Customer> customers = PhoneService.GetAllCustomers(); customer = customers.FirstOrDefault(c => c.Id == guid); if (customer == default(Customer)) { customer = null; } } catch { return(NotFound()); } if (customer == null) { return(NotFound()); } List <PhoneNumber> phoneNumbers = PhoneService.GetAllPhoneNumbers(); var results = phoneNumbers.Where(p => p.Customer == customer).ToList <PhoneNumber>(); return(Ok(results)); }