Create RelatedIssues module namespace

app/controllers/projects/related_issues_controller.rb

@@ -11,7 +11,7 @@ module Projects
 
     def create
       opts = { issue_references: params[:issue_references] }
-      result = CreateRelatedIssueService.new(issue, current_user, opts).execute
+      result = RelatedIssues::CreateService.new(issue, current_user, opts).execute
 
       render json: result, status: result['http_status']
     end

app/services/related_issues/create_service.rb

+module RelatedIssues
+  class CreateService < BaseService
+    def initialize(issue, user, params)
+      @issue, @current_user, @params = issue, user, params.dup
+    end
+
+    def execute
+      if referenced_issues.blank?
+        return error('No Issue found for given reference', 401)
+      end
+
+      begin
+        create_related_issues!
+      rescue => exception
+        return error(exception.message, 401)
+      end
+
+      success(message: "#{issues_sentence(referenced_issues)} were successfully related")
+    end
+
+    private
+
+    def create_related_issues!
+      RelatedIssue.transaction do
+        referenced_issues.each do |referenced_issue|
+          RelatedIssue.create!(issue: @issue, related_issue: referenced_issue)
+        end
+      end
+    end
+
+    def referenced_issues
+      @referenced_issues ||= begin
+        issue_references = params[:issue_references]
+        text = issue_references.join(' ')
+
+        extractor = Gitlab::ReferenceExtractor.new(@issue.project, @current_user)
+        extractor.analyze(text)
+
+        extractor.issues
+      end
+    end
+
+    def issues_sentence(issues)
+      issues.map { |issue| issue.to_reference(@issue.project) }.sort.to_sentence
+    end
+  end
+end

spec/controllers/projects/related_issues_controller_spec.rb

@@ -69,7 +69,7 @@ describe Projects::RelatedIssuesController, type: :controller do
   end
 
   describe 'POST #create' do
-    let(:service) { double(CreateRelatedIssueService, execute: service_response) }
+    let(:service) { double(RelatedIssues::CreateService, execute: service_response) }
     let(:service_response) { { 'message' => 'yay' } }
     let(:issue_references) { double }
     let(:user_role) { :developer }
@@ -77,7 +77,7 @@ describe Projects::RelatedIssuesController, type: :controller do
     before do
       project.team << [user, user_role]
 
-      allow(CreateRelatedIssueService).to receive(:new)
+      allow(RelatedIssues::CreateService).to receive(:new)
         .with(issue, user, { issue_references: issue_references })
         .and_return(service)
     end

spec/services/create_related_issue_service_spec.rb → spec/services/related_issues/create_service_spec.rb

 require 'spec_helper'
 
-describe CreateRelatedIssueService, service: true do
+describe RelatedIssues::CreateService, service: true do
   describe '#execute' do
     let(:namespace) { create :namespace }
     let(:project) { create :empty_project, namespace: namespace }