Add gitlab_web_url to jira issue entity

ee/app/serializers/integrations/jira/issue_entity.rb

@@ -3,6 +3,8 @@
 module Integrations
   module Jira
     class IssueEntity < Grape::Entity
+      include RequestAwareEntity
+
       expose :project_id do |_jira_issue, options|
         options[:project].id
       end
@@ -61,6 +63,14 @@ module Integrations
         "#{base_web_url(jira_issue)}/browse/#{jira_issue.key}"
       end
 
+      expose :gitlab_web_url do |jira_issue|
+        if ::Feature.enabled?(:jira_issues_show_integration, options[:project], default_enabled: :yaml)
+          project_integrations_jira_issue_path(options[:project], jira_issue.key)
+        else
+          nil
+        end
+      end
+
       expose :references do |jira_issue|
         {
           relative: jira_issue.key

ee/spec/serializers/integrations/jira/issue_entity_spec.rb

@@ -76,6 +76,7 @@ RSpec.describe Integrations::Jira::IssueEntity do
       it 'returns URLs including context path' do
         expect(subject[:author]).to include(web_url: 'http://jira.com/jira-sub-path/secure/ViewProfile.jspa?name=reporter@reporter.com')
         expect(subject[:web_url]).to eq('http://jira.com/jira-sub-path/browse/GL-5')
+        expect(subject[:gitlab_web_url]).to eq(Gitlab::Routing.url_helpers.project_integrations_jira_issue_path(project, 'GL-5'))
       end
     end
   end
@@ -109,4 +110,14 @@ RSpec.describe Integrations::Jira::IssueEntity do
       expect(subject).to include(labels: [])
     end
   end
+
+  context 'feature flag "jira_issues_show_integration" is disabled' do
+    before do
+      stub_feature_flags(jira_issues_show_integration: false)
+    end
+
+    it 'sets `gitlab_web_url` to nil' do
+      expect(subject[:gitlab_web_url]).to eq(nil)
+    end
+  end 
 end