Merge branch '6417-extract-ee-specific-files-lines-for-lib-gitlab-email-handler-rb' into 'master'

Resolve "Extract EE specific files/lines for lib/gitlab/email/handler.rb"

Closes #6417

See merge request gitlab-org/gitlab-ee!6975

ee/lib/ee/gitlab/email/handler.rb

+# frozen_string_literal: true
+
+module EE
+  module Gitlab
+    module Email
+      module Handler
+        extend ActiveSupport::Concern
+
+        class_methods do
+          extend ::Gitlab::Utils::Override
+
+          override :load_handlers
+          def load_handlers
+            [
+              ::Gitlab::Email::Handler::EE::ServiceDeskHandler,
+              *super
+            ]
+          end
+        end
+      end
+    end
+  end
+end

ee/lib/gitlab/email/handler/ee/service_desk_handler.rb

+# frozen_string_literal: true
+
 module Gitlab
   module Email
     module Handler

ee/spec/lib/gitlab/email/handler/ee/service_desk_handler_spec.rb

+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe Gitlab::Email::Handler::EE::ServiceDeskHandler do

ee/spec/lib/gitlab/email/handler_spec.rb

+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe Gitlab::Email::Handler do

lib/gitlab/email/handler.rb

-require 'gitlab/email/handler/create_merge_request_handler'
-require 'gitlab/email/handler/create_note_handler'
-require 'gitlab/email/handler/create_issue_handler'
-require 'gitlab/email/handler/unsubscribe_handler'
-
-require 'gitlab/email/handler/ee/service_desk_handler'
+# frozen_string_literal: true
 
 module Gitlab
   module Email
     module Handler
-      HANDLERS = [
-        EE::ServiceDeskHandler,
+      prepend ::EE::Gitlab::Email::Handler
+
+      def self.handlers
+        @handlers ||= load_handlers
+      end
+
+      def self.load_handlers
+        [
           UnsubscribeHandler,
           CreateNoteHandler,
           CreateMergeRequestHandler,
           CreateIssueHandler
-      ].freeze
+        ]
+      end
 
       def self.for(mail, mail_key)
-        HANDLERS.find do |klass|
+        handlers.find do |klass|
           handler = klass.new(mail, mail_key)
           break handler if handler.can_handle?
         end

lib/gitlab/email/handler/base_handler.rb

+# frozen_string_literal: true
+
 module Gitlab
   module Email
     module Handler

lib/gitlab/email/handler/create_issue_handler.rb

+# frozen_string_literal: true
+
 require 'gitlab/email/handler/base_handler'
 
 module Gitlab

lib/gitlab/email/handler/create_merge_request_handler.rb

+# frozen_string_literal: true
+
 require 'gitlab/email/handler/base_handler'
 require 'gitlab/email/handler/reply_processing'
 

lib/gitlab/email/handler/create_note_handler.rb

+# frozen_string_literal: true
+
 require 'gitlab/email/handler/base_handler'
 require 'gitlab/email/handler/reply_processing'
 

lib/gitlab/email/handler/reply_processing.rb

+# frozen_string_literal: true
+
 module Gitlab
   module Email
     module Handler

lib/gitlab/email/handler/unsubscribe_handler.rb

+# frozen_string_literal: true
+
 require 'gitlab/email/handler/base_handler'
 
 module Gitlab

spec/lib/gitlab/email/handler/create_issue_handler_spec.rb

+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe Gitlab::Email::Handler::CreateIssueHandler do

spec/lib/gitlab/email/handler/create_merge_request_handler_spec.rb

+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe Gitlab::Email::Handler::CreateMergeRequestHandler do

spec/lib/gitlab/email/handler/create_note_handler_spec.rb

+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe Gitlab::Email::Handler::CreateNoteHandler do

spec/lib/gitlab/email/handler/unsubscribe_handler_spec.rb

+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe Gitlab::Email::Handler::UnsubscribeHandler do

spec/lib/gitlab/email/handler_spec.rb

+# frozen_string_literal: true
+
 require 'spec_helper'
 
 describe Gitlab::Email::Handler do
@@ -40,7 +42,7 @@ describe Gitlab::Email::Handler do
   end
 
   def ce_handlers
-    @ce_handlers ||= Gitlab::Email::Handler::HANDLERS.reject do |handler|
+    @ce_handlers ||= Gitlab::Email::Handler.handlers.reject do |handler|
       handler.name.start_with?('Gitlab::Email::Handler::EE::')
     end
   end