Update blocking issues count on reopening

Refresh blocking issues count cache when reopening issue

app/services/issues/reopen_service.rb

@@ -5,6 +5,8 @@ module Issues
     def execute(issue)
       return issue unless can?(current_user, :reopen_issue, issue)
 
+      before_reopen(issue)
+
       if issue.reopen
         event_service.reopen_issue(issue, current_user)
         create_note(issue, 'reopened')
@@ -21,8 +23,14 @@ module Issues
 
     private
 
+    def before_reopen(issue)
+      # Overriden in EE
+    end
+
     def create_note(issue, state = issue.state)
       SystemNoteService.change_status(issue, issue.project, current_user, state, nil)
     end
   end
 end
+
+Issues::ReopenService.prepend_if_ee('EE::Issues::ReopenService')

ee/app/services/ee/issues/reopen_service.rb

+# frozen_string_literal: true
+
+module EE
+  module Issues
+    module ReopenService
+      extend ::Gitlab::Utils::Override
+
+      override :before_reopen
+      def before_reopen(issue)
+        # Assign blocking_issues_count to issue object instead of performing an update,
+        # this way we can keep issue#previous_changes attributes consistent.
+        # Some services may use them to perform callbacks like StatusPage::TriggerPublishService
+        issue.blocking_issues_count = ::IssueLink.blocking_issues_count_for(issue)
+
+        super
+      end
+    end
+  end
+end

ee/spec/services/ee/issues/reopen_service_spec.rb

+# frozen_string_literal: true
+
+require 'spec_helper'
+
+RSpec.describe Issues::ReopenService do
+  let_it_be(:project) { create(:project) }
+  let_it_be(:user) { create(:user) }
+  let_it_be(:issue) { create(:issue, :closed, project: project) }
+  let_it_be(:blocked_issue) { create(:issue, project: project) }
+
+  subject { described_class.new(project, user).execute(issue) }
+
+  before do
+    create(:issue_link, source: issue, target: blocked_issue, link_type: ::IssueLink::TYPE_BLOCKS)
+    issue.update!(blocking_issues_count: 0)
+  end
+
+  describe '#execute' do
+    context 'when user is not authorized to reopen issue' do
+      before do
+        project.add_guest(user)
+      end
+
+      it 'does not update blocking issues count' do
+        expect { subject }.not_to change { issue.blocking_issues_count }.from(0)
+      end
+    end
+
+    context 'when user is authorized to reopen issue' do
+      before do
+        project.add_maintainer(user)
+      end
+
+      it 'updates blocking issues count' do
+        expect { subject }.to change { issue.blocking_issues_count }.from(0).to(1)
+      end
+    end
+  end
+end