using System;

using System.Collections.Generic;

using System.Web;

using System.Linq;

​

public class Program

{

    public static void Main()

    {

        new UnitTests().PerformUnitTest();

    }

}

​

// INSTRUCTIONS:

// The CustomerManager class has an UpdateZip() method that updates a customer's

// zip code after validating it.  To do so, it retrieves a value from the current

// HttpContext and requires an API call to validate the new zip.

//

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

// without interacting with any of these external services and return two PASS lines

// in the console.  (If necessary, update other classes so that tests can execute.)

//

// UpdateZip() must still interact with the HttpContext and DbContext when run in the 

// context of the host application.

//

// Do not make any changes to PerformUnitTest().

​

public class UnitTests

{

    public void PerformUnitTest()

    {

        var sut = new CustomerManager(new CustomerRepositoryMock());

        var expected = true;

        var actual = sut.UpdateZip("12345"); // GOOD zip code

        var result = expected == actual ? "PASS" : "FAIL";

        Console.WriteLine(result);

        expected = false;

        actual = sut.UpdateZip("9999"); // BAD zip code

        result = expected == actual ? "PASS" : "FAIL";

        Console.WriteLine(result);

    }

}

​

public class CustomerManager

{

    // Add interface to allow mocking

    private ICustomerRepository _repository;

    // Default constructor uses normal repository

    public CustomerManager()

    {

        _repository = new CustomerRepository();

    }

    // Allow unit tests to inject their own implementation of repository

    public CustomerManager(ICustomerRepository repository)

    {

        _repository = repository;

    }

    public bool UpdateZip(string newZipCode)

    {

        var allZipCodes = GetAllValidZipCodes();

        if (allZipCodes.Contains(newZipCode))

        {

            int customerId = (int)HttpContext.Current.Profile.GetPropertyValue("CustomerId");

            _repository.UpdateZip(customerId, newZipCode);

            return true;

        }

        else

        {

            return false;

        }

    }

​

    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

{

    void UpdateZip(int customerId, string newZipCode);

}

​

public class CustomerRepository : ICustomerRepository

{

    public void UpdateZip(int customerId, string newZipCode)

    {

        var db = new DbContext();

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

        customer.ZipCode = newZipCode;

    }

}

​

public class CustomerRepositoryMock : ICustomerRepository

{

    private Dictionary<int, string> _codes = new Dictionary<int, string>();

​

    public void UpdateZip(int customerId, string newZipCode)

    {

        if (_codes.ContainsKey(customerId))

            _codes[customerId] = newZipCode;

        else

            _codes.Add(customerId, newZipCode);

    }

}

​

public class DbContext

{

    public List<Customer> Customers

    {

        get;

        set;

    }

}

​

public class HttpClient

{

    public T Get<T>(string url)

    {

        // perform HTTP call and return response

        return default(T);

    }

}