Add dirty methods for store accessors

activerecord/lib/active_record/store.rb

@@ -11,6 +11,10 @@ module ActiveRecord
   # of the model. This is very helpful for easily exposing store keys to a form or elsewhere that's
   # already built around just accessing attributes on the model.
   #
+  # Every accessor comes with dirty tracking methods (+key_changed?+, +key_was+ and +key_change+).
+  #
+  # NOTE: There is no +key_will_change!+ method for accessors, use +store_will_change!+ instead.
+  #
   # Make sure that you declare the database column used for the serialized store as a text, so there's
   # plenty of room.
   #
@@ -49,6 +53,12 @@ module ActiveRecord
   #   u.settings[:country]  # => 'Denmark'
   #   u.settings['country'] # => 'Denmark'
   #
+  #   # Dirty tracking
+  #   u.color = 'green'
+  #   u.color_changed? # => true
+  #   u.color_was # => 'black'
+  #   u.color_change # => ['black', 'red']
+  #
   #   # Add additional accessors to an existing store through store_accessor
   #   class SuperUser < User
   #     store_accessor :settings, :privileges, :servants
@@ -127,6 +137,24 @@ def store_accessor(store_attribute, *keys, prefix: nil, suffix: nil)
             define_method(accessor_key) do
               read_store_attribute(store_attribute, key)
             end
+
+            define_method("#{accessor_key}_changed?") do
+              return false unless attribute_changed?(store_attribute)
+              prev_store, new_store = changes[store_attribute]
+              prev_store&.dig(key) != new_store&.dig(key)
+            end
+
+            define_method("#{accessor_key}_change") do
+              return unless attribute_changed?(store_attribute)
+              prev_store, new_store = changes[store_attribute]
+              [prev_store&.dig(key), new_store&.dig(key)]
+            end
+
+            define_method("#{accessor_key}_was") do
+              return unless attribute_changed?(store_attribute)
+              prev_store, _new_store = changes[store_attribute]
+              prev_store&.dig(key)
+            end
           end
         end
 

activerecord/test/cases/adapters/postgresql/hstore_test.rb

@@ -153,6 +153,22 @@ def test_yaml_round_trip_with_store_accessors
     assert_equal "GMT", y.timezone
   end
 
+  def test_changes_with_store_accessors
+    x = Hstore.new(language: "de")
+    assert x.language_changed?
+    assert_nil x.language_was
+    assert_equal [nil, "de"], x.language_change
+    x.save!
+
+    assert_not x.language_changed?
+    x.reload
+
+    x.settings = nil
+    assert x.language_changed?
+    assert_equal "de", x.language_was
+    assert_equal ["de", nil], x.language_change
+  end
+
   def test_changes_in_place
     hstore = Hstore.create!(settings: { "one" => "two" })
     hstore.settings["three"] = "four"

activerecord/test/cases/store_test.rb

@@ -79,6 +79,63 @@ class StoreTest < ActiveRecord::TestCase
     assert_not_predicate @john, :settings_changed?
   end
 
+  test "updating the store will mark accessor as changed" do
+    @john.color = "red"
+    assert @john.color_changed?
+  end
+
+  test "new record and no accessors changes" do
+    user = Admin::User.new
+    assert_not user.color_changed?
+    assert_nil user.color_was
+    assert_nil user.color_change
+
+    user.color = "red"
+    assert user.color_changed?
+    assert_nil user.color_was
+    assert_equal "red", user.color_change[1]
+  end
+
+  test "updating the store won't mark accessor as changed if the whole store was updated" do
+    @john.settings = { color: @john.color, some: "thing" }
+    assert @john.settings_changed?
+    assert_not @john.color_changed?
+  end
+
+  test "updating the store populates the accessor changed array correctly" do
+    @john.color = "red"
+    assert_equal "black", @john.color_was
+    assert_equal "black", @john.color_change[0]
+    assert_equal "red", @john.color_change[1]
+  end
+
+  test "updating the store won't mark accessor as changed if the value isn't changed" do
+    @john.color = @john.color
+    assert_not @john.color_changed?
+  end
+
+  test "nullifying the store mark accessor as changed" do
+    color = @john.color
+    @john.settings = nil
+    assert @john.color_changed?
+    assert_equal color, @john.color_was
+    assert_equal [color, nil], @john.color_change
+  end
+
+  test "dirty methods for suffixed accessors" do
+    @john.configs[:two_factor_auth] = true
+    assert @john.two_factor_auth_configs_changed?
+    assert_nil @john.two_factor_auth_configs_was
+    assert_equal [nil, true], @john.two_factor_auth_configs_change
+  end
+
+  test "dirty methods for prefixed accessors" do
+    @john.spouse[:name] = "Lena"
+    assert @john.partner_name_changed?
+    assert_equal "Dallas", @john.partner_name_was
+    assert_equal ["Dallas", "Lena"], @john.partner_name_change
+  end
+
   test "object initialization with not nullable column" do
     assert_equal true, @john.remember_login
   end