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

{   

    public void PerformUnitTest()

    {

        // add in mock repositories for testing

        var sut = new CustomerValidator(new TestCustomerRepository(), new TestZipCodeService());

        var expected = true;

        var actual = sut.GetCustomerAndValidateZip(1);

        CompareResults(expected, actual);

        expected = false;

        actual = sut.GetCustomerAndValidateZip(2);

        CompareResults(expected, actual);

    }

​

    private void CompareResults(bool expected, bool actual)

    {

        Console.WriteLine(expected == actual ? "PASS" : "FAIL");

    }

}

​

public class CustomerValidator

{

    ICustomerRepository _customerRepo;

    IZipCodeService _zipService;

    // deafult customer validator to using the actual services by default

    public CustomerValidator()

    {

        _customerRepo = new CustomerRepository();

        _zipService = new ZipCodeService();

    }

    // allow for setting custom interface implementations

    public CustomerValidator(ICustomerRepository customerRepo, IZipCodeService zipService)

    {

        _customerRepo = customerRepo;

        _zipService = zipService;

    }

    // allow to optionally send customer ID

    public bool GetCustomerAndValidateZip(int? customerId = null)

    {

        var repository = new CustomerRepository();

        // if the function wasn't called with a customer ID, get the customer ID from the HttpContext

        if(!customerId.HasValue)

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

        var customer = _customerRepo.GetCustomer(customerId.Value);

        var allZipCodes = _zipService.GetAllValidZipCodes();

        return allZipCodes.Contains(customer.ZipCode);

    }

}

​

public interface IZipCodeService

{

    List<string> GetAllValidZipCodes();

}

​

public class ZipCodeService : IZipCodeService

{

    public List<string> GetAllValidZipCodes()

    {

        var httpClient = new HttpClient();

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

    }

}

​

public class TestZipCodeService : IZipCodeService

{

    public List<string> GetAllValidZipCodes()

    {

        return new List<string>()

        {

            "12345"

        };

    }

}

​

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 TestCustomerRepository : ICustomerRepository

{

    DbContext _context;

    public TestCustomerRepository()

    {

        _context = new DbContext();

        _context.Customers = new List<Customer>(){

            new Customer

            {

                ID = 1,

                ZipCode = "12345"

            },

            new Customer

            {

                ID = 2,

                ZipCode = "23456"

            }

        };

    }

​

    public Customer GetCustomer(int customerId)

    {

        return _context.Customers.FirstOrDefault(c => c.ID == customerId);

    }

}

​

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);

    }

}