Mocking an IoC Container?

Question

Does it make sense to mock an IoC container? If so how would I go about it, using Moq?

I am creating a Prism 4 app, using Unity 2.0 as the IoC container. I inject th

Answer 1

I agree with Mark Seemann's answer generally for 99% of classes this works fine.

There are some factory type classes (perhaps classes that take a Model and convert it to a ViewModel where those ViewModels have dependencies) for which this doesn't work. In these cases, I generally accept the interface for the container, rather than its concrete type (IUnityContainer, in your case) and mock as usual.

public class MyWidgetFactory : IMyWidgetFactory
{
     public MyWidgetFactory(IUnityContainer container)
     {
          //...
     }
     public Widget[] GetWidgets()
     {
         //...
     }
}

public class MyWidgetFactoryConsumer
{
     private Widget[] _widgets;
     public MyWidgetFactoryConsumer(IMyWidgetFactory factory)
     {
          _widgets = factory.GetWidgets();
     }
}

Both of the above classes are testable, with the factory class needing to have a mocked version of the IUnityContainer and the consumer needing only the factory itself mocked.