public void can_get_an_expando_object_to_act_as_an_interface() { dynamic expando = Build <ExpandoObject> .NewObject( Prop1 : "Test", Prop2 : 42L, Prop3 : Guid.NewGuid(), Meth1 : Return <bool> .Arguments <int>(it => it > 5) ); IMyInterface myInterface = Impromptu.ActLike(expando); Assert.Equal("Test", myInterface.Prop1); Assert.Equal(true, myInterface.Meth1(10)); }