Refactor

app/helpers/epp/domains_helper.rb

@@ -1,18 +1,11 @@
 module Epp::DomainsHelper
   def create_domain
-    domain = Domain.new(domain_create_params)
+    @domain = Domain.new(domain_create_params)
 
-    if domain.save
+    if @domain.save
       render '/epp/domains/create'
     else
-      if domain.errors.added?(:name, :taken)
-        @code = '2302'
-        @msg = 'Domain name already exists'
-      elsif domain.errors.added?(:name, :epp_domain_reserved)
-        @code = '2302'
-        @msg = domain.errors[:name].first
-      end
-
+      handle_domain_name_errors
       render '/epp/error'
     end
   end
@@ -37,4 +30,14 @@ module Epp::DomainsHelper
       auth_info: ph[:authInfo][:pw]
     }
   end
+
+  def handle_domain_name_errors
+    [:epp_domain_taken, :epp_domain_reserved].each do |x|
+      if @domain.errors.added?(:name, x)
+        @code = '2302'
+        @msg = @domain.errors[:name].first
+      end
+    end
+  end
+
 end

app/models/domain.rb

@@ -8,7 +8,7 @@ class Domain < ActiveRecord::Base
   belongs_to :technical_contact, class_name: 'Contact'
   belongs_to :admin_contact, class_name: 'Contact'
 
-  validates :name, domain_name: true, uniqueness: true
+  validates :name, domain_name: true, uniqueness: { message: I18n.t('errors.messages.epp_domain_taken') }
   validates :name_puny, domain_name: true
 
   def name=(value)

config/locales/en.yml

@@ -23,4 +23,5 @@ en:
   errors:
     messages:
       epp_domain_reserved: 'Domain name is reserved or restricted'
+      epp_domain_taken: 'Domain name already exists'
   hello: "Hello world"