Use new requires_attribute method in poll

app/controllers/epp/polls_controller.rb

@@ -38,9 +38,6 @@ class Epp::PollsController < EppController
   private
 
   def validate_poll
-    op = params[:parsed_frame].css('poll').first[:op]
-    return true if %w(ack req).include?(op)
-    epp_errors << { code: '2306', msg: I18n.t('errors.messages.attribute_op_is_invalid') }
-    false
+    requires_attribute 'poll', 'op', values: %(ack req)
   end
 end

app/controllers/epp_controller.rb

@@ -79,7 +79,7 @@ class EppController < ApplicationController
       full_selector = [@prefix, selector].join(' ')
       el = params[:parsed_frame].css(full_selector).first
 
-      missing = el.nil? || (el.text.blank? && el.children.none?)
+      missing = el.nil?
 
       epp_errors << {
         code: '2003',

spec/epp/domain_spec.rb

@@ -213,7 +213,7 @@ describe 'EPP Domain', epp: true do
       xml = domain_create_xml(ns: [])
       response = epp_plain_request(xml, :xml)
       response[:result_code].should == '2003'
-      response[:msg].should == 'Required parameter missing: ns'
+      response[:msg].should == 'Required parameter missing: ns > hostAttr'
     end
 
     it 'does not create domain with too many nameservers' do

spec/epp/keyrelay_spec.rb

@@ -75,7 +75,6 @@ describe 'EPP Keyrelay', epp: true do
     xml = epp_xml.keyrelay({
       name: { value: domain.name },
       keyData: {
-        flags: { value: '' },
         protocol: { value: '3' },
         alg: { value: '8' },
         pubKey: { value: 'cmlraXN0aGViZXN0' }
@@ -89,7 +88,7 @@ describe 'EPP Keyrelay', epp: true do
     })
 
     response = epp_request(xml, :xml, :elkdata)
-    response[:msg].should == 'Required parameter missing: flags'
+    response[:msg].should == 'Required parameter missing: keyData > flags'
 
     @zone.messages.queued.count.should == msg_count
   end

spec/epp/poll_spec.rb

@@ -25,7 +25,6 @@ describe 'EPP Poll', epp: true do
   it 'returns no messages in poll' do
     ApiLog::EppLog.delete_all
     response = epp_plain_request(epp_xml.poll, :xml)
-
     response[:msg].should == 'Command completed successfully; no messages'
     response[:result_code].should == '1300'
 
@@ -89,7 +88,7 @@ describe 'EPP Poll', epp: true do
     })
 
     response = epp_plain_request(xml, :xml)
-    response[:msg].should == 'Attribute op is invalid'
+    response[:msg].should == 'Attribute is invalid: op'
   end
 
   it 'dequeues multiple messages' do