using System;

using System.Collections.Generic;

using System.Web;

using System.Linq;

​

public class Program

{

    public static void Main()

    {

        new UnitTests().PerformUnitTest();

    }

}

​

// INSTRUCTIONS:

​

// The CustomerValidator class retrieves a value from the current HttpContext,

// uses that value to pull a record from the database, plus makes an API call.

​

// Refactor CustomerValidator so that the PerformUnitTest() method can execute 

// without interacting with any of these external services.  GetCustomerAndValidateZip()

// must still interact with all these services when run in the context of the

// host application.

​

// Adjust the unit test so that it tests one good zip code and one bad one,

// resulting in two "PASS" lines in the console.

​

// Focus on what needs to change in CustomerValidator() and UnitTests():

// changes to the other classes would be expected in real life, but are not

// necessary for this activity.

public class UnitTests

{   

    private static List<string> _validZips = new List<string> { "37738", "37064" };

    public class TestClient1 : IHttpClient {

        public int GetCustomerId() {

            return 1;   

        }

        public List<string> GetAllValidZipCodes() {

            return _validZips;

        }

    }

    public class TestClient2 : IHttpClient {

        public int GetCustomerId() {

            return 2;   

        }

        public List<string> GetAllValidZipCodes() {

            return _validZips;

        }

    }

    public class TestRepo : ICustomerRepository {

        public Customer GetCustomer(int customerId)

        {

            var customers = new List<Customer> {

                new Customer { ID = 1, ZipCode = "37738" },

                new Customer { ID = 2, ZipCode = "ABCDE" }

            };

            return customers.SingleOrDefault(p => p.ID == customerId);

        }

    }

    public void PerformUnitTest()

    {

        // mock repo

        ICustomerRepository repo = new TestRepo();

        // mock clients

        IHttpClient client1 = new TestClient1();

        IHttpClient client2 = new TestClient2();

        // test 1 -> testing valid one

        var sut1 = new CustomerValidator(repo, client1);

        var expected1 = true;

        var actual1 = sut1.GetCustomerAndValidateZip();

        var result1 = expected1 == actual1 ? "PASS" : "FAIL";

        Console.WriteLine(result1);

        // test 2 -> testing invalid one

        var sut2 = new CustomerValidator(repo, client2);

        var expected2 = true;

        var actual2 = sut2.GetCustomerAndValidateZip();

        var result2 = expected2 == actual2 ? "FAIL" : "PASS";

        Console.WriteLine(result2);

    }

}

​

public class CustomerValidator

{

    private readonly ICustomerRepository _customerRepository;

    private readonly IHttpClient _httpClient;

    public CustomerValidator(ICustomerRepository customerRepository, IHttpClient httpClient) {

        _customerRepository = customerRepository;   

        _httpClient = httpClient;

    }

    public bool GetCustomerAndValidateZip()

    {

        int customerId = _httpClient.GetCustomerId();

        var customer = _customerRepository.GetCustomer(customerId);

        var allZipCodes = _httpClient.GetAllValidZipCodes();

        return allZipCodes.Contains(customer.ZipCode);

    }

​

    private List<string> GetAllValidZipCodes()

    {

        var httpClient = new HttpClient();

        return httpClient.Get<List<string>>("http://somezipcodeapi.com/GetAll");

    }

}

​

public class Customer

{

    public int ID { get; set; }

    public string ZipCode { get; set; }

}

​

public interface ICustomerRepository {

    Customer GetCustomer(int customerId);

}

​

public class CustomerRepository : ICustomerRepository

{

    public Customer GetCustomer(int customerId)

    {

        var db = new DbContext();

        return db.Customers.SingleOrDefault(i => i.ID == customerId);

    }

}

​

public class DbContext

{

    public List<Customer> Customers { get; set; }

}

​

public interface IHttpClient {

    int GetCustomerId();

    List<string> GetAllValidZipCodes();

}

​

public class HttpClient : IHttpClient

{

    public T Get<T>(string url)

    {

        // perform HTTP call and return response

        return default(T);

    }

    public int GetCustomerId() {

        return (int)HttpContext.Current.Profile.GetPropertyValue("CustomerId");

    }

    public List<string> GetAllValidZipCodes()

    {

        return this.Get<List<string>>("http://somezipcodeapi.com/GetAll");

    }

}