Support for virtual attributes and redefined method accessors

lib/paper_trail/version_concern.rb

@@ -186,6 +186,8 @@ module PaperTrail
         attrs.each do |k, v|
           if model.has_attribute?(k)
             model[k.to_sym] = v
+          elsif model.respond_to?("#{k}=")
+            model.send("#{k}=", v)
           else
             logger.warn "Attribute #{k} does not exist on #{item_type} (Version id: #{id})."
           end

test/dummy/app/models/song.rb

@@ -1,6 +1,7 @@
 # Example from 'Overwriting default accessors' in ActiveRecord::Base.
 class Song < ActiveRecord::Base
   has_paper_trail
+  attr_accessor :name
 
   # Uses an integer of seconds to hold the length of the song
   def length=(minutes)
@@ -9,4 +10,19 @@ class Song < ActiveRecord::Base
   def length
     read_attribute(:length) / 60
   end
+
+  # override attributes hashes like some libraries do
+  def attributes_with_name
+    attributes_without_name.tap do |_hash|
+      _hash.merge!(:name => name) if name
+    end
+  end
+  alias_method_chain :attributes, :name
+
+  def changed_attributes_with_name
+    changed_attributes_without_name.tap do |_hash|
+      _hash.merge!(:name => name) if name
+    end
+  end
+  alias_method_chain :changed_attributes, :name
 end

test/unit/model_test.rb

@@ -1126,6 +1126,21 @@ class HasPaperTrailModelTest < ActiveSupport::TestCase
     should 'return "overwritten" value on reified instance' do
       assert_equal 4, @song.versions.last.reify.length
     end
+
+    context 'Has a virtual attribute injected into the ActiveModel::Dirty changes' do
+      setup do
+        @song.name = 'Good Vibrations'
+        @song.save
+        @song.name = nil
+      end
+
+      should 'return persist the changes on the live instance properly' do
+        assert_equal nil, @song.name
+      end
+      should 'return "overwritten" virtual attribute on the reified instance' do
+        assert_equal 'Good Vibrations', @song.versions.last.reify.name
+      end
+    end
   end