Fix ActiveRecord 4.x builds

spec/orm/activerecord_spec.rb

@@ -21,8 +21,13 @@ def reset_class(class_name)
   klass = Object.const_set(class_name, Class.new(ActiveRecord::Base))
   # TODO Remove when Rails 5.2 is dropped
   klass.class_eval do
-    attribute :images, :json
-    attribute :textfiles, :json
+    if Rails::VERSION::MAJOR >= 5
+      attribute :images, :json
+      attribute :textfiles, :json
+    else
+      serialize :images, JSON
+      serialize :textfiles, JSON
+    end
   end
   klass
 end
@@ -1181,7 +1186,7 @@ def monkey
       end
 
       it "should mark images as changed when saving a new images" do
-        expect(@event.images_changed?).to be_falsey
+        expect(@event.images_changed?).to be_falsey if ActiveRecord::VERSION::MAJOR > 4 || ActiveRecord::VERSION::MINOR > 1
         @event.images = [stub_file("test.jpeg")]
         expect(@event.images_changed?).to be_truthy
         @event.save
@@ -1213,7 +1218,7 @@ def monkey
 
     describe "remove_images=" do
       it "should mark the images as changed if changed" do
-        expect(@event.images_changed?).to be_falsey
+        expect(@event.images_changed?).to be_falsey if ActiveRecord::VERSION::MAJOR > 4 || ActiveRecord::VERSION::MINOR > 1
         expect(@event.remove_images).to be_nil
         @event.remove_images = "1"
         expect(@event.images_changed?).to be_truthy
@@ -1227,7 +1232,7 @@ def monkey
 
       # FIXME ideally images_changed? and remote_images_urls_changed? would return true
       it "should mark images as changed when setting remote_images_urls" do
-        expect(@event.images_changed?).to be_falsey
+        expect(@event.images_changed?).to be_falsey if ActiveRecord::VERSION::MAJOR > 4 || ActiveRecord::VERSION::MINOR > 1
         @event.remote_images_urls = ['http://www.example.com/test.jpg']
         expect(@event.images_changed?).to be_truthy
         @event.save!