public void GenerateAndApplyReversePatch() { var initial = new PhoneBook() { Entries = new Dictionary <string, TestPerson>() { ["0800JOHNDOE"] = new TestPerson() { FirstName = "John", LastName = "Doe", IsAdult = true, }, ["0800JANEDOE"] = new TestPerson() { FirstName = "Jane", LastName = "Doe", IsAdult = true, }, }, }; using DraftScope scope = (DraftScope)DraftExtensions.CreateDraft(initial, out PhoneBook draft); var patchGenerator = new DictionaryPatchGenerator(); var patches = new JsonPatchDocument(); var inversePatches = new JsonPatchDocument(); draft.Entries.Remove("0800JANEDOE"); draft.Entries.Add("0800BABYDOE", new TestPerson() { FirstName = "Baby", LastName = "Doe", }); // trick the scope into thinking that is finishing and should not create proxies anymore. scope.IsFinishing = true; patchGenerator.Generate((IDraft)draft.Entries, "/Entries", patches, inversePatches); // inverse order of inverse patches. inversePatches.Operations.Reverse(); var final = scope.FinishDraft <PhoneBook, IPhoneBook>(draft); var result = IPhoneBook.Produce(initial, p => { patches.ApplyTo(p); }); result = result.Produce(p => { inversePatches.ApplyTo(p); }); Assert.Equal(2, result.Entries.Count); Assert.Same(initial.Entries["0800JOHNDOE"], result.Entries["0800JOHNDOE"]); Assert.Same(initial.Entries["0800JANEDOE"], result.Entries["0800JANEDOE"]); }