Verifying event registration using Moq

Question

I\'m developing an asp.net (classic) application trying to implement the MVP pattern using this example. In trying to unit test my presenter and using the following pattern,

Answer 1

I know it's maybe too late for #Dilip, but this answer can be helpful for those who are trying to do the same. Here is the test class

public delegate void SubscriptionHandler(string name, T handler);

public class SomePresenterTest
{
    [Test]
    public void Subscription_Test()
    {
        var someServiceMock = new Mock();
        var viewMock = new Mock();
        //Setup your viewMock here

        var someView = new FakeView(viewMock.Object);
        EventHandler initHandler = null;            
        someView.Subscription += (n, h) => { if ((nameof(someView.Init)).Equals(n)) initHandler=h; };

        Assert.IsNull(initHandler);

        var presenter = new SomePresenter(someServiceMock.Object, someView);

        Assert.IsNotNull(initHandler);
        Assert.AreEqual("OnInit", initHandler.Method?.Name);
    }
}

FakeView is a decorator implemented as follow (pay attention to Events:Init/Load{add;remove}):

public class FakeView : IView
{
    public event SubscriptionHandler Subscription;
    public event SubscriptionHandler Unsubscription;
    private IView _view;
    public FakeView(IView view)
    {
        Assert.IsNotNull(view);
        _view = view;
    }

    public bool IsPostBack => _view.IsPostBack;
    public bool IsValid => _view.IsValid;

    public event EventHandler Init
    {
        add
        {
            Subscription?.Invoke(nameof(Init), value);
            _view.Init += value;
        }

        remove
        {
            Unsubscription?.Invoke(nameof(Init), value);
            _view.Init -= value;
        }
    }
    public event EventHandler Load
    {

        add
        {
            Subscription?.Invoke(nameof(Load), value);
            _view.Init += value;
        }

        remove
        {
            Unsubscription?.Invoke(nameof(Load), value);
            _view.Init -= value;
        }
    }

    public void DataBind()
    {
        _view.DataBind();
    }
}