Duplicate domain validation

app/helpers/epp/domains_helper.rb

@@ -1,7 +1,16 @@
 module Epp::DomainsHelper
   def create_domain
-    domain = Domain.create!(domain_create_params)
+    domain = Domain.new(domain_create_params)
+
+    if domain.save
       render '/epp/domains/create'
+    else
+      if domain.errors.added?(:name_dirty, :taken)
+        @code = '2302'
+        @msg = 'Domain name already exists'
+      end
+      render '/epp/error'
+    end
   end
 
   def check_domain

app/models/domain.rb

@@ -9,6 +9,7 @@ class Domain < ActiveRecord::Base
   belongs_to :admin_contact, class_name: 'Contact'
 
   validates :name, domain_name: true
+  validates :name_dirty, uniqueness: true
   validates :name_puny, domain_name: true
 
   def name=(value)

spec/epp/domain_spec.rb

@@ -15,6 +15,14 @@ describe 'EPP Domain', epp: true do
       expect(Domain.first.registrar.name).to eq('Zone Media OÜ')
     end
 
+    it 'does not create duplicate domain' do
+      epp_request('domains/create.xml')
+      response = epp_request('domains/create.xml')
+      expect(response[:result_code]).to eq('2302')
+      expect(response[:msg]).to eq('Domain name already exists')
+      expect(response[:clTRID]).to eq('ABC-12345')
+    end
+
     it 'checks a domain' do
       response = epp_request('domains/check.xml')
       expect(response[:result_code]).to eq('1000')