wrap an existing instance of an interface

[jpribele]

What I want to do put a mock around around existing instance so I that I verify that the methods are called

IFoo foo = GetFoo();
var mock = new Mock( foo );
mock.Setup(....)

The only way I can see to this is to implement IFoo myself that wraps the foo instance and then do
new Mock(foo)

is there some other way to do this?

[GillesTourreau]

It is not the concept of Moq and it is not possible to setup an existing instance.
The only thing that you can do is to create create an instance of the Foo class like that:

var mock = new Mock<Foo>();
mock.Setup(....)

The Foo class must be non-sealed and the methods that you setup must be virtual or abstract.

[jpribele]

Feature Request?
I can do it manually.
class MockFoo : Mock
{
MockFoo(IFoo foo)
{
Setup(m => m.DoStuff()).Callback(m=> foo.DoStuff());
}
}
For a large interface its a lot of stuff to write.