#306

backend/app/models/version_record.rb

@@ -1,15 +1,23 @@
 module VersionRecord
   extend ActiveSupport::Concern
 
+  DEFAULT_EVENT_TYPE_MAP = { create: 'create',
+                             update: 'update',
+                             discard: 'discard',
+                             restore: 'restore' }.freeze
+
   def readonly? = persisted?
 
   included do
+    event_type_map = if const_defined?(:EVENT_TYPE_MAP, false)
+                       const_get(:EVENT_TYPE_MAP)
+                     else
+                       DEFAULT_EVENT_TYPE_MAP
+                     end
+
     belongs_to :created_by_user, class_name: 'User', optional: true
 
-    enum :event_type, { create: 'create',
-                        update: 'update',
-                        discard: 'discard',
-                        restore: 'restore' }, prefix: true, validate: true
+    enum :event_type, event_type_map, prefix: true, validate: true
 
     validates :version_no, presence: true, numericality: { only_integer: true, greater_than: 0 }
     validates :event_type, presence: true