Support enumerization of the same attribute in child class. (#448)

Author: nashby

lib/enumerize/activerecord.rb

@@ -124,6 +124,8 @@ def serialize(value)
       end
 
       def cast(value)
+        return value if @subtype.is_a?(Type)
+
         if value.is_a?(::Enumerize::Value)
           value
         else

test/activerecord_test.rb

@@ -693,6 +693,15 @@ def self.name
     expect(user2.skill).must_equal 'casual'
   end
 
+  it 'works when child class calls enumerize second time' do
+    class AdminUser < User
+      enumerize :account_type, in: [:basic, :premium, :pro]
+    end
+
+    admin = AdminUser.create(account_type: 'pro')
+    expect(admin.account_type).must_equal 'pro'
+  end
+
   if Rails::VERSION::MAJOR >= 6
     it 'supports AR#insert_all' do
       User.delete_all