Initial RelatedIssuesController#index

app/controllers/projects/related_issues_controller.rb

+module Projects
+  class RelatedIssuesController < ApplicationController
+    include IssuesHelper
+
+    before_action :authorize_read_issue!, only: [:index]
+
+    def index
+      render json: serialize_as_json
+    end
+
+    def create
+    end
+
+    private
+
+    # 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)
+                    .execute
+                    .where(iid: params[:issue_id])
+                    .first!
+    end
+  end
+end

config/routes/project.rb

@@ -311,6 +311,8 @@ constraints(ProjectUrlConstrainer.new) do
           post :bulk_update
           post :export_csv
         end
+
+        resources :related_issues, only: [:index, :create]
       end
 
       resources :project_members, except: [:show, :new, :edit], constraints: { id: /[a-zA-Z.\/0-9_\-#%+]+/ }, concerns: :access_requestable do

spec/controllers/projects/related_issues_controller_spec.rb

+require 'rails_helper'
+
+describe Projects::RelatedIssuesController, type: :controller do
+  let(:user) { create :user }
+  let(:project) { create(:project_empty_repo) }
+  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!(: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
+
+    let!(:related_issue_c) do
+      create(:related_issue, issue: issue_d,
+                             related_issue: issue,
+                             created_at: Date.today)
+    end
+
+    it "returns related issues JSON" do
+      sign_in user
+      project.team << [user, :developer]
+
+      get :index, namespace_id: issue.project.namespace,
+                  project_id: issue.project,
+                  issue_id: issue,
+                  format: :json
+
+
+
+      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}"
+        }
+      )
+    end
+  end
+
+  xdescribe "GET #create" do
+    it "returns http success" do
+      get :create
+      expect(response).to have_http_status(:success)
+    end
+  end
+end

spec/factories/related_issues.rb

+FactoryGirl.define do
+  factory :related_issue do
+    issue
+    related_issue factory: :issue
+  end
+end