Mock service without interfaces using rhino mocks

Question

Background My application is consuming a WCF service via proxyies. I have to unit test my implementation, that it consume the service and processing are done correctly.

Method to be Tested

public class MyClass
{ 
 private ManagerServiceClientImpl myclient;

 public void MethodToBeTested();
 {
    var result = GetServiceData();
    if(result!=null)
       //some processing
 }
}

private MyObject GetServiceData()
{
    myclient = ServiceLocator.Current.GetInstance<ManagerServiceClientImpl>();
    if(myclient.ConnectToService() && myclient.MyServiceClient.IsConnected)
       return myclient.GetData();
    else
     return null;
}

This is provided by external source, so I have no right to modify it

public class ManagerServiceClientImpl
{
  public ServiceClient MyServiceClient { get; private set; }
  public bool ConnectToService()
}

How would I mock the ManagerServiceClientImpl it doesn't have interface or methods are not marked as virtual

What i tried so far.

[TestMethod]
public void IsServiceConnected_GetData()
{

  //Arrange
  ManagerServiceClientImpl clientImpl = 
               MockRepository.GenerateMock<ManagerServiceClientImpl>();

  ServiceLocator.Expect(x => x.GetInstance<ManagerServiceClientImpl>())
                .Return(clientImpl);

  var testData= new MyObject 
  {
            ID = "Test1",
            Name ="test",
  }

  //Act
  _myClass.MethodToBeTested();

  //Assert
  stubService.AssertWasCalled(h => h.SaveAllChanges());
}

Note: Using Rhino.Mocks. Its my first time using Rhino mocks

Wrap 3 rd party dependencies in an abstraction you control in your code and would be able to modify and mock. Avoid service locator anti-pattern which makes the code difficult to test as you have already discovered. This is a design issue. — Nkosi
First you need to clarify the method to be tested as your example is unclear. — Nkosi
I didn't understand you fully MethodToBeTested(); is to be tested. The logic in the method is very small. If the service data is not in inventory add to the inventory. Im not sure is this what you asking for. pardon my enlgish ` — Eldho
Check your small example and see if it even compiles. this is not a minimal reproducible example. The code you have tried so far also refers to methods that are not even indicated in the method under test. You see what I mean right? — Nkosi

JamesR JamesR · Accepted Answer · 2017-04-30T08:44:31

As Amittai Shapira mentioned you can mock it without an interface by using unit testing frameworks that support it, i'm using Typemock Isolator and i created an example test for your code:

I've created an instance of MyClass and used a feature of Typemock to mock Non-Public methods to change the return value for GetServiceData

[TestMethod]
public void TestMethod1()
{
    var testData = new MyObject
    {
        ID = "Test1",
        Name = "test",
    };

    var realObj = new MyClass();
    Isolate.NonPublic.WhenCalled(realObj, "GetServiceData").WillReturn(testData);
    Isolate.NonPublic.WhenCalled(realObj, "SaveAllChanges").CallOriginal();

    realObj.MethodToBeTested();

    Isolate.Verify.NonPublic.WasCalled(realObj, "SaveAllChanges");
}

Mock service without interfaces using rhino mocks

2 Answers