Improve EPP error handling

Fixes #539

app/models/epp/contact.rb

@@ -154,10 +154,17 @@ class Epp::Contact < Contact
                                     type: ident_frame.attr('type'),
                                     country_code: ident_frame.attr('cc'))
 
-        report_valid_ident_error if submitted_ident != identifier
+        if submitted_ident != identifier
+          add_epp_error('2308', nil, nil, I18n.t('epp.contacts.errors.valid_ident'))
+          return
+        end
       else
         ident_update_attempt = ident_frame.text.present? && (ident_frame.text != ident)
-        report_ident_update_error if ident_update_attempt
+
+        if ident_update_attempt
+          add_epp_error('2308', nil, nil, I18n.t('epp.contacts.errors.ident_update'))
+          return
+        end
 
         identifier = Ident.new(code: ident,
                                type: ident_frame.attr('type'),
@@ -243,14 +250,4 @@ class Epp::Contact < Contact
     frame.css("legalDocument").first.content = doc.path if doc&.persisted?
     self.legal_document_id = doc.id
   end
-
-  private
-
-  def report_valid_ident_error
-    throw :epp_error, { code: '2308', msg: I18n.t('epp.contacts.errors.valid_ident') }
-  end
-
-  def report_ident_update_error
-    throw :epp_error, { code: '2308', msg: I18n.t('epp.contacts.errors.ident_update') }
-  end
 end

app/models/epp/domain.rb

@@ -451,10 +451,8 @@ class Epp::Domain < Domain
     return super if frame.blank?
 
     if discarded?
-      throw :epp_error, {
-        code: '2304',
-        msg: 'Object status prohibits operation',
-      }
+      add_epp_error('2304', nil, nil, 'Object status prohibits operation')
+      return
     end
 
     at = {}.with_indifferent_access
@@ -531,10 +529,8 @@ class Epp::Domain < Domain
 
   def epp_destroy(frame, user_id)
     if discarded?
-      throw :epp_error, {
-        code: '2304',
-        msg: 'Object status prohibits operation',
-      }
+      add_epp_error('2304', nil, nil, 'Object status prohibits operation')
+      return
     end
 
     if doc = attach_legal_document(Epp::Domain.parse_legal_document_from_frame(frame))
@@ -554,10 +550,10 @@ class Epp::Domain < Domain
   end
 
   def set_pending_delete!
-    throw :epp_error, {
-      code: '2304',
-      msg: I18n.t(:object_status_prohibits_operation)
-    } unless pending_deletable?
+    unless pending_deletable?
+      add_epp_error('2304', nil, nil, I18n.t(:object_status_prohibits_operation))
+      return
+    end
 
     self.delete_date = Time.zone.today + Setting.redemption_grace_period.days + 1.day
     set_pending_delete
@@ -601,10 +597,8 @@ class Epp::Domain < Domain
 
   def transfer(frame, action, current_user)
     if discarded?
-      throw :epp_error, {
-        code: '2106',
-        msg: 'Object is not eligible for transfer',
-      }
+      add_epp_error('2106', nil, nil, 'Object is not eligible for transfer')
+      return
     end
 
     @is_transfer = true
@@ -624,10 +618,8 @@ class Epp::Domain < Domain
 
   def query_transfer(frame, current_user)
     if current_user.registrar == registrar
-      throw :epp_error, {
-        code: '2002',
-        msg: I18n.t(:domain_already_belongs_to_the_querying_registrar)
-      }
+      add_epp_error('2002', nil, nil, I18n.t(:domain_already_belongs_to_the_querying_registrar))
+      return
     end
 
     transaction do
@@ -661,11 +653,10 @@ class Epp::Domain < Domain
 
   def approve_transfer(frame, current_user)
     pt = pending_transfer
+
     if current_user.registrar != pt.old_registrar
-      throw :epp_error, {
-        msg: I18n.t('transfer_can_be_approved_only_by_current_registrar'),
-        code: '2304'
-      }
+      add_epp_error('2304', nil, nil, I18n.t('transfer_can_be_approved_only_by_current_registrar'))
+      return
     end
 
     transaction do
@@ -687,11 +678,10 @@ class Epp::Domain < Domain
 
   def reject_transfer(frame, current_user)
     pt = pending_transfer
+
     if current_user.registrar != pt.old_registrar
-      throw :epp_error, {
-        msg: I18n.t('transfer_can_be_rejected_only_by_current_registrar'),
-        code: '2304'
-      }
+      add_epp_error('2304', nil, nil, I18n.t('transfer_can_be_rejected_only_by_current_registrar'))
+      return
     end
 
     transaction do

app/models/epp/response/result/code.rb

@@ -26,6 +26,7 @@ module Epp
           object_association_prohibits_operation: 2305,
           parameter_value_policy_error: 2306,
           data_management_policy_violation: 2308,
+          command_failed: 2400,
           authentication_error_server_closing_connection: 2501,
         }.freeze
         private_constant :KEY_TO_VALUE
@@ -52,6 +53,7 @@ module Epp
           2305 => 'Object association prohibits operation',
           2306 => 'Parameter value policy error',
           2308 => 'Data management policy violation',
+          2400 => 'Command failed',
           2501 => 'Authentication error; server closing connection',
         }.freeze
         private_constant :DEFAULT_DESCRIPTIONS