Question

Given 2 interfaces having one function in common

public interface I1 { void Foo(string p);};
public interface I2 { void Foo(string p);};

We create a mock of both interfaces using moq

Mock<I1> menuServiceMock = new Mock<I1>();
menuServiceMock.As<I2>();

The problem is that when you call Foo on I2

(menuServiceMock.Object as I2).Foo("foo"); // in real code, we have a handle on I2

You cannot verify it with:

menuServiceMock.Verify(x => x.Foo("foo"), Times.Once());

…because only calls to I1::Foo are counted.

How can we overcome that (apart from reversing I1 and I2 in mock construction)?

Answer 1

I think you need to do this:

Mock<I1> menuServiceMock = new Mock<I1>();
var i2Mock = menuServiceMock.As<I2>();

// Verifies that I2.Foo was called on the object
i2Mock.Verify(x => x.Foo("foo"), Times.Once());
// Verifies that I1.Foo was called on the object:
menuServiceMock.Verify(x => x.Foo("foo"), Times.Once());