Init Jira issue show

- Adds show haml template and basic vue app
to render an individual issue
- Add jira_issue_detail_view feature flag

config/feature_flags/development/jira_issues_show_integration.yml

+---
+name: jira_issues_show_integration
+introduced_by_url: https://gitlab.com/gitlab-org/gitlab/-/merge_requests/52446
+rollout_issue_url: https://gitlab.com/gitlab-org/gitlab/-/issues/299832
+milestone: '13.9'
+type: development
+group: group::ecosystem
+default_enabled: false

ee/app/assets/javascripts/integrations/jira/issues_show/components/jira_issues_show_root.vue

+<script>
+export default {
+  name: 'JiraIssuesShow',
+};
+</script>
+
+<template>
+  <div></div>
+</template>

ee/app/assets/javascripts/integrations/jira/issues_show/jira_issues_show_bundle.js

+import Vue from 'vue';
+
+import JiraIssuesShowApp from './components/jira_issues_show_root.vue';
+
+export default function initJiraIssueShow({ mountPointSelector }) {
+  const mountPointEl = document.querySelector(mountPointSelector);
+
+  if (!mountPointEl) {
+    return null;
+  }
+
+  return new Vue({
+    el: mountPointEl,
+    render: (createElement) => createElement(JiraIssuesShowApp),
+  });
+}

ee/app/assets/javascripts/pages/projects/integrations/jira/issues/show/index.js

+import initJiraIssueShow from 'ee/integrations/jira/issues_show/jira_issues_show_bundle';
+
+initJiraIssueShow({ mountPointSelector: '.js-jira-issues-show-app' });

ee/app/controllers/projects/integrations/jira/issues_controller.rb

@@ -9,6 +9,7 @@ module Projects
         include SortingPreference
 
         before_action :check_feature_enabled!
+        before_action :check_issues_show_enabled!, only: :show
 
         before_action do
           push_frontend_feature_flag(:jira_issues_integration, project, type: :licensed, default_enabled: true)
@@ -76,6 +77,10 @@ module Projects
           return render_404 unless project.jira_issues_integration_available? && project.jira_service.issues_enabled
         end
 
+        def check_issues_show_enabled!
+          render_404 unless ::Feature.enabled?(:jira_issues_show_integration, @project, default_enabled: :yaml)
+        end
+
         # Return the informational message to the user
         def render_integration_error(exception)
           render json: { errors: [exception.message] }, status: :bad_request

ee/app/views/projects/integrations/jira/issues/show.html.haml

+.js-jira-issues-show-app

ee/config/routes/project.rb

@@ -110,7 +110,7 @@ constraints(::Constraints::ProjectUrlConstrainer.new) do
 
         namespace :integrations do
           namespace :jira do
-            resources :issues, only: [:index]
+            resources :issues, only: [:index, :show]
           end
         end
 

ee/spec/controllers/projects/integrations/jira/issues_controller_spec.rb

@@ -172,4 +172,30 @@ RSpec.describe Projects::Integrations::Jira::IssuesController do
       end
     end
   end
+
+  describe 'GET #show' do
+    context 'when `jira_issues_show_integration` feature is disabled' do
+      before do
+        stub_feature_flags(jira_issues_show_integration: false)
+      end
+
+      it 'returns 404 status' do
+        get :show, params: { namespace_id: project.namespace, project_id: project, id: 1 }
+
+        expect(response).to have_gitlab_http_status(:not_found)
+      end
+    end
+
+    context 'when `jira_issues_show_integration` feature is enabled' do
+      before do
+        stub_feature_flags(jira_issues_show_integration: true)
+      end
+
+      it 'renders `show` template' do
+        get :show, params: { namespace_id: project.namespace, project_id: project, id: 1 }
+
+        expect(response).to render_template(:show)
+      end
+    end
+  end
 end