Merge pull request #13776 from rails/dirty-enum

Implement the Dirty API with the Enum feature correctly.

Conflicts:
	activerecord/CHANGELOG.md

2 files changed, 36 insertions, 4 deletions

diff --git a/activerecord/lib/active_record/attribute_methods/dirty.rb b/activerecord/lib/active_record/attribute_methods/dirty.rb
index 19e81abba5..68168bb729 100644
--- a/activerecord/lib/active_record/attribute_methods/dirty.rb
+++ b/activerecord/lib/active_record/attribute_methods/dirty.rb
@@ -43,6 +43,12 @@ module ActiveRecord
       def write_attribute(attr, value)
         attr = attr.to_s
 
+        save_changed_attribute(attr, value)
+
+        super(attr, value)
+      end
+
+      def save_changed_attribute(attr, value)
         # The attribute already has an unsaved change.
         if attribute_changed?(attr)
           old = changed_attributes[attr]
@@ -51,9 +57,6 @@ module ActiveRecord
           old = clone_attribute_value(:read_attribute, attr)
           changed_attributes[attr] = old if _field_changed?(attr, old, value)
         end
-
-        # Carry on.
-        super(attr, value)
       end
 
       def update_record(*)
diff --git a/activerecord/lib/active_record/enum.rb b/activerecord/lib/active_record/enum.rb
index 3deb2d65f8..53dde5e564 100644
--- a/activerecord/lib/active_record/enum.rb
+++ b/activerecord/lib/active_record/enum.rb
@@ -63,6 +63,12 @@ module ActiveRecord
   #
   #   Conversation.where("status <> ?", Conversation.statuses[:archived])
   module Enum
+    DEFINED_ENUMS = {} # :nodoc:
+
+    def enum_mapping_for(attr_name) # :nodoc:
+      DEFINED_ENUMS[attr_name.to_s]
+    end
+
     def enum(definitions)
       klass = self
       definitions.each do |name, values|
@@ -107,6 +113,8 @@ module ActiveRecord
             # def active!() update! status: :active end
             define_method("#{value}!") { update! name => value }
           end
+
+          DEFINED_ENUMS[name.to_s] = enum_values
         end
       end
     end
@@ -114,7 +122,28 @@ module ActiveRecord
     private
       def _enum_methods_module
         @_enum_methods_module ||= begin
-          mod = Module.new
+          mod = Module.new do
+            private
+              def save_changed_attribute(attr_name, value)
+                if (mapping = self.class.enum_mapping_for(attr_name))
+                  if attribute_changed?(attr_name)
+                    old = changed_attributes[attr_name]
+
+                    if mapping[old] == value
+                      changed_attributes.delete(attr_name)
+                    end
+                  else
+                    old = clone_attribute_value(:read_attribute, attr_name)
+
+                    if old != value
+                      changed_attributes[attr_name] = mapping.key old
+                    end
+                  end
+                else
+                  super
+                end
+              end
+          end
           include mod
           mod
         end