I am trying to store a list of Mocks and some of them have multiple interfaces. I have to use the base Mock type as the type of the list and I would expect the following to work:

    [Fact]
    public void ShouldExpectGetFromBaseMock()
    {
        var list = new List<IMock>
            {
                new Mock<IFoo>().As<IBag>()
            };

        bool called = false;

        list[0].As<IFoo>().SetupGet(x => x.Value)
            .Callback(() => called = true)
            .Returns(25);

        Assert.Equal(25, ((IFoo)list[0].Object).Value);
        Assert.True(called);
    }

The AsInterface.Object isn't overriding the base Mock.Object because there is a 'new' keyword on Mock<>.Object (it's changing the output type).

In the Moq.csproj file, on the ILMerge step, the "/targetplatform:v2,$(MSBuildToolsPath)" switch is causing problems when built for v3.5. It crashes the ILMerge tool. I can fix it by removing the MSBuildToolsPath part.

don't the published 3.5 bits work just fine?

The best way I could figure to solve this is to have AsInterface implement a IMock interface directly so it can override the Mock.Object and redirect it to the owner object.

I've attached the diff file with the unit test and the modified source files. Let me know if a better solution is possible.

The published bits didn't work, and it was actually pretty hard to get v3.5 to compile. I ended up changing the msbuild and csproj files to v3.5. I didn't include those changes in the diff, except for the ILMerge problem.

As for the test, add it to one of your test classes, change IMock back to Mock, and see if it works. The returned object from ((Mock)new Mock().As()).Object doesn't have any interfaces implemented because the redirection at the AsInterface layer isn't being picked up when accessing a Mock typed object.