public void service_undoes_are_in_the_correct_order() { var p1 = new Person(null, false); var p2 = new Person(null, false); var p3 = new Person(null, false); ChangeTrackingService svc = new ChangeTrackingService(); PersonCollection list = new PersonCollection(svc); list.Add(p1); list.Add(p2); list.Add(p3); list.Move(p2, 0); list.Remove(p1); svc.Undo(); Assert.AreEqual <int>(3, list.Count); Assert.IsTrue(list.Contains(p1)); svc.Undo(); Assert.AreEqual <int>(1, list.IndexOf(p2)); svc.Undo(); Assert.AreEqual <int>(2, list.Count); Assert.IsFalse(list.Contains(p3)); svc.Undo(); Assert.AreEqual <int>(1, list.Count); Assert.IsFalse(list.Contains(p2)); svc.Undo(); Assert.AreEqual <int>(0, list.Count); Assert.IsFalse(list.Contains(p1)); }