Some moq

gistfile1.cs

using Machine.Specifications;
using Moq;
using It = Machine.Specifications.It;

namespace AssetsOptimizer.Specs.Web
{
    public class MockSpec
    {
        static string test = "orig";
        static Mock<IDep> dependency;

        Establish context = () =>
            {
                dependency = new Mock<IDep>();
                dependency.Setup(x => x.Foo())
                          .Returns(test);
            };

        Because of = () => test = "changed";

        It should_return_changed_value = () => dependency.Object.Foo().ShouldEqual("changed");
    }

    public interface  IDep
    {
        string Foo();
    }
}

Result of it

should return changed value : Failed Expected string length 7 but was 4. Strings differ at index 0.
Expected: "changed"
But was: "orig"
-----------^