Move listing logic to RelatedIssues::ListService

app/controllers/projects/related_issues_controller.rb

 module Projects
   class RelatedIssuesController < ApplicationController
-    include IssuesHelper
-
     before_action :authorize_read_related_issue!
     before_action :authorize_admin_related_issue!, only: [:create]
 
     def index
-      render json: serialize_as_json
+      render json: RelatedIssues::ListService.new(issue, current_user).execute
     end
 
     def create
@@ -26,27 +24,6 @@ module Projects
       return render_404 unless can?(current_user, :read_related_issue, @project)
     end
 
-    # TODO: Move to service class
-    def serialize_as_json
-      related_issues.map do |related_issue|
-        referenced_issue = related_issue.related_issue == issue ? related_issue.issue : related_issue.related_issue
-
-        {
-          title: referenced_issue.title,
-          state: referenced_issue.state,
-          reference: referenced_issue.to_reference(@project),
-          path: url_for_issue(referenced_issue.iid, @project, only_path: true),
-        }
-      end
-    end
-
-    def related_issues
-      RelatedIssue
-        .where("issue_id = #{issue.id} OR related_issue_id = #{issue.id}")
-        .preload(:related_issue, :issue)
-        .order(:created_at)
-    end
-
     def issue
       @issue ||=
         IssuesFinder.new(current_user, project_id: project.id)

app/services/related_issues/list_service.rb

+module RelatedIssues
+  class ListService
+    include Gitlab::Routing
+
+    def initialize(issue, user)
+      @issue, @current_user = issue, user
+    end
+
+    def execute
+      related_issues.map do |related_issue|
+        referenced_issue =
+          if related_issue.related_issue == @issue
+            related_issue.issue
+          else
+            related_issue.related_issue
+          end
+
+        {
+          title: referenced_issue.title,
+          state: referenced_issue.state,
+          reference: referenced_issue.to_reference(@issue.project),
+          path: namespace_project_issue_path(referenced_issue.project.namespace, referenced_issue.project, referenced_issue.iid)
+        }
+      end
+    end
+
+    private
+
+    def related_issues
+      RelatedIssue
+        .where("issue_id = #{@issue.id} OR related_issue_id = #{@issue.id}")
+        .preload(related_issue: :project, issue: :project)
+        .order(:created_at)
+    end
+  end
+end
\ No newline at end of file

spec/controllers/projects/related_issues_controller_spec.rb

@@ -6,65 +6,28 @@ describe Projects::RelatedIssuesController, type: :controller do
   let(:issue) { create :issue, project: project }
 
   describe 'GET #index' do
-    let(:issue_b) { create :issue, project: project }
-    let(:issue_c) { create :issue, project: project }
-    let(:issue_d) { create :issue, project: project }
+    let(:service) { double(RelatedIssues::ListService, execute: service_response) }
+    let(:service_response) { [{ 'foo' => 'bar' }] }
 
-    let!(:related_issue_a) do
-      create(:related_issue, issue: issue,
-                             related_issue: issue_b,
-                             created_at: 2.days.ago)
-    end
-
-    let!(:related_issue_b) do
-      create(:related_issue, issue: issue,
-                             related_issue: issue_c,
-                             created_at: 1.day.ago)
-    end
+    before do
+      project.team << [user, :guest]
+      sign_in user
 
-    let!(:related_issue_c) do
-      create(:related_issue, issue: issue_d,
-                             related_issue: issue,
-                             created_at: Date.today)
+      allow(RelatedIssues::ListService).to receive(:new)
+        .with(issue, user)
+        .and_return(service)
     end
 
-    it 'returns related issues JSON' do
-      sign_in user
-      project.team << [user, :developer]
-
+    subject do
       get :index, namespace_id: issue.project.namespace,
                   project_id: issue.project,
                   issue_id: issue,
                   format: :json
+    end
 
-      expect(json_response.size).to eq(3)
-
-      expect(json_response[0]).to eq(
-        {
-          "title" => issue_b.title,
-          "state" => issue_b.state,
-          "reference" => issue_b.to_reference(project),
-          "path" => "/#{project.full_path}/issues/#{issue_b.iid}"
-        }
-      )
-
-      expect(json_response[1]).to eq(
-        {
-          "title" => issue_c.title,
-          "state" => issue_c.state,
-          "reference" => issue_c.to_reference(project),
-          "path" => "/#{project.full_path}/issues/#{issue_c.iid}"
-        }
-      )
-
-      expect(json_response[2]).to eq(
-        {
-          "title" => issue_d.title,
-          "state" => issue_d.state,
-          "reference" => issue_d.to_reference(project),
-          "path" => "/#{project.full_path}/issues/#{issue_d.iid}"
-        }
-      )
+    it 'returns JSON response' do
+      is_expected.to have_http_status(200)
+      expect(json_response).to eq(service_response)
     end
   end
 
@@ -76,6 +39,7 @@ describe Projects::RelatedIssuesController, type: :controller do
 
     before do
       project.team << [user, user_role]
+      sign_in user
 
       allow(RelatedIssues::CreateService).to receive(:new)
         .with(issue, user, { issue_references: issue_references })
@@ -83,8 +47,6 @@ describe Projects::RelatedIssuesController, type: :controller do
     end
 
     subject do
-      sign_in user
-
       post :create, namespace_id: issue.project.namespace,
                     project_id: issue.project,
                     issue_id: issue,

spec/services/related_issues/list_service_spec.rb

+require 'spec_helper'
+
+describe RelatedIssues::ListService, service: true do
+  describe '#execute' do
+    let(:user) { create :user }
+    let(:project) { create(:project_empty_repo) }
+    let(:issue) { create :issue, project: project }
+
+    let(:issue_b) { create :issue, project: project }
+    let(:issue_c) { create :issue, project: project }
+    let(:issue_d) { create :issue, project: project }
+
+
+    let!(:related_issue_c) do
+      create(:related_issue, issue: issue_d,
+                             related_issue: issue,
+                             created_at: Date.today)
+    end
+
+    let!(:related_issue_b) do
+      create(:related_issue, issue: issue,
+                             related_issue: issue_c,
+                             created_at: 1.day.ago)
+    end
+
+    let!(:related_issue_a) do
+      create(:related_issue, issue: issue,
+                             related_issue: issue_b,
+                             created_at: 2.days.ago)
+    end
+
+    subject { described_class.new(issue, user).execute }
+
+    it 'verifies number of queries' do
+      recorded = ActiveRecord::QueryRecorder.new { subject }
+      expect(recorded.count).to be_within(1).of(29)
+    end
+
+    it 'returns related issues JSON' do
+      expect(subject.size).to eq(3)
+
+      expect(subject[0]).to eq(
+        {
+          title: issue_b.title,
+          state: issue_b.state,
+          reference: issue_b.to_reference(project),
+          path: "/#{project.full_path}/issues/#{issue_b.iid}"
+        }
+      )
+
+      expect(subject[1]).to eq(
+        {
+          title: issue_c.title,
+          state: issue_c.state,
+          reference: issue_c.to_reference(project),
+          path: "/#{project.full_path}/issues/#{issue_c.iid}"
+        }
+      )
+
+      expect(subject[2]).to eq(
+        {
+          title: issue_d.title,
+          state: issue_d.state,
+          reference: issue_d.to_reference(project),
+          path: "/#{project.full_path}/issues/#{issue_d.iid}"
+        }
+      )
+    end
+  end
+end