Moq具有“新”成员的模拟接口

Question

I'm having problems mocking an set of interfaces:

interface IFoo
{
    object Blah { get; }
}

interface IBar : IFoo
{
    new string Blah { get; }
}

I tried mocking as:

var mock = new Mock<IFoo>();
mock.SetupGet(m => m.Blah).Returns("Blah");

This works now:

Assert.That(mock.Object.Blah, Is.EqualTo("Blah"));

The problem is that when I add the following, to also have a value for the IBar interface, the value of IFoo.Blah is null.

var bar = mock.As<IBar>();
bar.SetupGet(m => m.Blah).Returns("Blah");

This works now:

Assert.That(((IBar)mock.Object).Blah, Is.EqualTo("Blah"));

But the old one fails:

Assert.That(mock.Object.Blah, Is.EqualTo("Blah"));
// mock.Object.Blah is null now

Is there a way to get both to work?

Answer 1

With MOQ (v4.0.10827) and .Net 4, this code is working:

var mock = new Mock<IFoo>();
var bar = mock.As<IBar>();
mock.SetupGet(m => m.Blah).Returns("Blah");
Assert.That(mock.Object.Blah, Is.EqualTo("Blah"));
bar.SetupGet(m => m.Blah).Returns("BlahBlah");
Assert.That(((IBar)mock.Object).Blah, Is.EqualTo("BlahBlah"));
Assert.That(mock.Object.Blah, Is.EqualTo("Blah"));

You must initialize your interface before setting up your property.

Answer 2

I think you need to use "override" instead of "new". When you use "new", you're actually making a second function. Here's the doc: http://msdn.microsoft.com/en-us/library/ms173153.aspx