Possibility to preserve skipped attributes on reify

lib/paper_trail/version_concern.rb

@@ -162,6 +162,8 @@ def object_changes_col_is_json?
     #                       This option is handy for people who want to persist the reified version.
     # :dup                  `false` default behavior
     #                       `true` it always create a new object instance. It is useful for comparing two versions of the same object
+    # :preserve             `false` default behaviour
+    #                       `true` preserve attributes of reified object instead of setting unknown attributes to nil
     def reify(options = {})
       return nil if object.nil?
 
@@ -191,7 +193,9 @@ def reify(options = {})
         if options[:dup] != true && item
           model = item
           # Look for attributes that exist in the model and not in this version. These attributes should be set to nil.
-          (model.attribute_names - attrs.keys).each { |k| attrs[k] = nil }
+          if options[:preserve] != true
+            (model.attribute_names - attrs.keys).each { |k| attrs[k] = nil }
+          end
         else
           inheritance_column_name = item_type.constantize.inheritance_column
           class_name = attrs[inheritance_column_name].blank? ? item_type : attrs[inheritance_column_name]
@@ -200,7 +204,7 @@ def reify(options = {})
           # to look for the item outside of default scope(s)
           if options[:dup] || (_item = klass.unscoped.find_by_id(item_id)).nil?
             model = klass.new
-          else
+          elsif options[:preserve] != true
             model = _item
             # Look for attributes that exist in the model and not in this version. These attributes should be set to nil.
             (model.attribute_names - attrs.keys).each { |k| attrs[k] = nil }

spec/models/skipper_spec.rb

@@ -1,16 +1,45 @@
 require 'rails_helper'
 
 describe Skipper, :type => :model do
-  describe "#update_attributes!", :versioning => true do
-    context "updating a skipped attribute" do
-      let(:t1) { Time.zone.local(2015, 7, 15, 20, 34, 0) }
-      let(:t2) { Time.zone.local(2015, 7, 15, 20, 34, 30) }
+  with_versioning do
+    it { is_expected.to be_versioned }
 
-      it "should not create a version" do
-        skipper = Skipper.create!(:another_timestamp => t1)
-        expect {
-          skipper.update_attributes!(:another_timestamp => t2)
-        }.to_not change { skipper.versions.length }
+    describe "#update_attributes!", :versioning => true do
+      context "updating a skipped attribute" do
+        let(:t1) { Time.zone.local(2015, 7, 15, 20, 34, 0) }
+        let(:t2) { Time.zone.local(2015, 7, 15, 20, 34, 30) }
+
+        it "should not create a version" do
+          skipper = Skipper.create!(:another_timestamp => t1)
+          expect {
+            skipper.update_attributes!(:another_timestamp => t2)
+          }.to_not change { skipper.versions.length }
+        end
+      end
+    end
+
+    describe "reify" do
+      context "reifying a with a skipped attribute" do
+        let(:t1) { Time.zone.local(2015, 7, 15, 20, 34, 0) }
+        let(:t2) { Time.zone.local(2015, 7, 15, 20, 34, 30) }
+
+        context "without preserve (default)" do
+          it "should have no timestamp" do
+            skipper = Skipper.create!(:another_timestamp => t1)
+            skipper.update_attributes!(:another_timestamp => t2, name: "Foobar")
+            skipper = skipper.versions.last.reify
+            expect(skipper.another_timestamp).to be(nil)
+          end
+        end
+
+        context "with preserve" do
+          it "should preserve its timestamp" do
+            skipper = Skipper.create!(:another_timestamp => t1)
+            skipper.update_attributes!(:another_timestamp => t2, name: "Foobar")
+            skipper = skipper.versions.last.reify(preserve: true)
+            expect(skipper.another_timestamp).to eq(t2)
+          end
+        end
       end
     end
   end

test/dummy/db/migrate/20110208155312_set_up_test_tables.rb

@@ -1,6 +1,7 @@
 class SetUpTestTables < ActiveRecord::Migration
   def self.up
     create_table :skippers, :force => true do |t|
+      t.string   :name
       t.datetime :another_timestamp
       t.timestamps :null => true
     end

test/dummy/db/schema.rb

@@ -13,77 +13,108 @@
 
 ActiveRecord::Schema.define(version: 20110208155312) do
 
-  create_table "animals", force: true do |t|
+  create_table "animals", force: :cascade do |t|
     t.string "name"
     t.string "species"
   end
 
-  create_table "articles", force: true do |t|
+  create_table "articles", force: :cascade do |t|
     t.string "title"
     t.string "content"
     t.string "abstract"
     t.string "file_upload"
   end
 
-  create_table "authorships", force: true do |t|
+  create_table "authorships", force: :cascade do |t|
     t.integer "book_id"
     t.integer "person_id"
   end
 
-  create_table "books", force: true do |t|
+  create_table "banana_versions", force: :cascade do |t|
+    t.string   "item_type",  null: false
+    t.integer  "item_id",    null: false
+    t.string   "event",      null: false
+    t.string   "whodunnit"
+    t.text     "object"
+    t.datetime "created_at"
+  end
+
+  add_index "banana_versions", ["item_type", "item_id"], name: "index_banana_versions_on_item_type_and_item_id"
+
+  create_table "bananas", force: :cascade do |t|
+    t.datetime "created_at"
+    t.datetime "updated_at"
+  end
+
+  create_table "books", force: :cascade do |t|
     t.string "title"
   end
 
-  create_table "customers", force: true do |t|
+  create_table "boolits", force: :cascade do |t|
+    t.string  "name"
+    t.boolean "scoped", default: true
+  end
+
+  create_table "customers", force: :cascade do |t|
     t.string "name"
   end
 
-  create_table "documents", force: true do |t|
+  create_table "documents", force: :cascade do |t|
     t.string "name"
   end
 
-  create_table "editors", force: true do |t|
+  create_table "editors", force: :cascade do |t|
     t.string "name"
   end
 
-  create_table "editorships", force: true do |t|
+  create_table "editorships", force: :cascade do |t|
     t.integer "book_id"
     t.integer "editor_id"
   end
 
-  create_table "fluxors", force: true do |t|
+  create_table "fluxors", force: :cascade do |t|
     t.integer "widget_id"
     t.string  "name"
   end
 
-  create_table "gadgets", force: true do |t|
+  create_table "fruits", force: :cascade do |t|
+    t.string "name"
+    t.string "color"
+  end
+
+  create_table "gadgets", force: :cascade do |t|
     t.string   "name"
     t.string   "brand"
     t.datetime "created_at"
     t.datetime "updated_at"
   end
 
-  create_table "legacy_widgets", force: true do |t|
+  create_table "legacy_widgets", force: :cascade do |t|
     t.string  "name"
     t.integer "version"
   end
 
-  create_table "line_items", force: true do |t|
+  create_table "line_items", force: :cascade do |t|
     t.integer "order_id"
     t.string  "product"
   end
 
-  create_table "orders", force: true do |t|
+  create_table "not_on_updates", force: :cascade do |t|
+    t.datetime "created_at"
+    t.datetime "updated_at"
+  end
+
+  create_table "orders", force: :cascade do |t|
     t.integer "customer_id"
     t.string  "order_date"
   end
 
-  create_table "people", force: true do |t|
+  create_table "people", force: :cascade do |t|
     t.string "name"
     t.string "time_zone"
   end
 
-  create_table "post_versions", force: true do |t|
+  create_table "post_versions", force: :cascade do |t|
     t.string   "item_type",  null: false
     t.integer  "item_id",    null: false
     t.string   "event",      null: false
@@ -96,31 +127,38 @@
 
   add_index "post_versions", ["item_type", "item_id"], name: "index_post_versions_on_item_type_and_item_id"
 
-  create_table "post_with_statuses", force: true do |t|
+  create_table "post_with_statuses", force: :cascade do |t|
     t.integer "status"
   end
 
-  create_table "posts", force: true do |t|
+  create_table "posts", force: :cascade do |t|
     t.string "title"
     t.string "content"
   end
 
-  create_table "songs", force: true do |t|
+  create_table "skippers", force: :cascade do |t|
+    t.string   "name"
+    t.datetime "another_timestamp"
+    t.datetime "created_at"
+    t.datetime "updated_at"
+  end
+
+  create_table "songs", force: :cascade do |t|
     t.integer "length"
   end
 
-  create_table "things", force: true do |t|
+  create_table "things", force: :cascade do |t|
     t.string "name"
   end
 
-  create_table "translations", force: true do |t|
+  create_table "translations", force: :cascade do |t|
     t.string "headline"
     t.string "content"
     t.string "language_code"
     t.string "type"
   end
 
-  create_table "version_associations", force: true do |t|
+  create_table "version_associations", force: :cascade do |t|
     t.integer "version_id"
     t.string  "foreign_key_name", null: false
     t.integer "foreign_key_id"
@@ -129,7 +167,7 @@
   add_index "version_associations", ["foreign_key_name", "foreign_key_id"], name: "index_version_associations_on_foreign_key"
   add_index "version_associations", ["version_id"], name: "index_version_associations_on_version_id"
 
-  create_table "versions", force: true do |t|
+  create_table "versions", force: :cascade do |t|
     t.string   "item_type",      null: false
     t.integer  "item_id",        null: false
     t.string   "event",          null: false
@@ -149,13 +187,13 @@
 
   add_index "versions", ["item_type", "item_id"], name: "index_versions_on_item_type_and_item_id"
 
-  create_table "whatchamajiggers", force: true do |t|
+  create_table "whatchamajiggers", force: :cascade do |t|
     t.string  "owner_type"
     t.integer "owner_id"
     t.string  "name"
   end
 
-  create_table "widgets", force: true do |t|
+  create_table "widgets", force: :cascade do |t|
     t.string   "name"
     t.text     "a_text"
     t.integer  "an_integer"
@@ -171,7 +209,7 @@
     t.datetime "updated_at"
   end
 
-  create_table "wotsits", force: true do |t|
+  create_table "wotsits", force: :cascade do |t|
     t.integer  "widget_id"
     t.string   "name"
     t.datetime "created_at"