Send notifications for epic status change

- add sending notifications to epics close/reopen services
- add epics status change email templates
- add methods to epics mailer and notification service

ee/app/mailers/emails/epics.rb

@@ -11,6 +11,18 @@ module Emails
       mail_new_thread(@epic, epic_thread_options(@epic.author_id, recipient_id, reason))
     end
 
+    def epic_status_changed_email(recipient_id, epic_id, status, updated_by_user_id, reason = nil)
+      @epic = Epic.find_by_id(epic_id)
+      return unless @epic
+
+      setup_epic_mail(recipient_id)
+
+      @status = status
+      @updated_by = User.find(updated_by_user_id)
+
+      mail_answer_thread(@epic, epic_thread_options(updated_by_user_id, recipient_id, reason))
+    end
+
     private
 
     def setup_epic_mail(recipient_id)

ee/app/services/ee/notification_service.rb

@@ -42,6 +42,14 @@ module EE
       new_resource_email(epic, :new_epic_email)
     end
 
+    def close_epic(epic, current_user)
+      epic_status_change_email(epic, current_user, 'closed')
+    end
+
+    def reopen_epic(epic, current_user)
+      epic_status_change_email(epic, current_user, 'reopened')
+    end
+
     def project_mirror_user_changed(new_mirror_user, deleted_user_name, project)
       mailer.project_mirror_user_changed_email(new_mirror_user.id, deleted_user_name, project.id).deliver_later
     end
@@ -98,5 +106,21 @@ module EE
 
       mailer.service_desk_new_note_email(issue.id, note.id).deliver_later
     end
+
+    def epic_status_change_email(target, current_user, status)
+      action = status == 'reopened' ? 'reopen' : 'close'
+
+      recipients = NotificationRecipientService.build_recipients(
+        target,
+        current_user,
+        action: action
+      )
+
+      recipients.each do |recipient|
+        mailer.epic_status_changed_email(
+          recipient.user.id, target.id, status, current_user.id, recipient.reason)
+          .deliver_later
+      end
+    end
   end
 end

ee/app/services/epics/close_service.rb

@@ -14,6 +14,7 @@ module Epics
       if epic.close
         epic.update(closed_by: current_user)
         SystemNoteService.change_status(epic, nil, current_user, epic.state)
+        notification_service.close_epic(epic, current_user)
       end
     end
   end

ee/app/services/epics/reopen_service.rb

@@ -13,6 +13,7 @@ module Epics
     def reopen_epic(epic)
       if epic.reopen
         SystemNoteService.change_status(epic, nil, current_user, epic.state)
+        notification_service.reopen_epic(epic, current_user)
       end
     end
   end

ee/app/views/notify/epic_status_changed_email.html.haml

+%p
+  Epic was #{@status} by #{@updated_by.name}
+
+%p
+  Epic
+  = link_to @epic.to_reference, group_epic_url(@epic.group, @epic)

ee/app/views/notify/epic_status_changed_email.text.haml

+Epic was #{@status} by #{@updated_by.name}
+
+Epic #{@epic.to_reference}: #{group_epic_url(@epic.group, @epic)}

ee/changelogs/unreleased/7272-epics-notifications.yml

+---
+title: Send notifications for epic status change
+merge_request: 8247
+author:
+type: added

ee/spec/services/ee/notification_service_spec.rb

@@ -255,25 +255,25 @@ describe EE::NotificationService, :mailer do
     end
   end
 
-  describe 'Notes' do
+  describe 'epics' do
+    set(:group) { create(:group, :private) }
+    set(:epic) { create(:epic, group: group) }
+
     around do |example|
       perform_enqueued_jobs do
         example.run
       end
     end
 
+    before do
+      stub_licensed_features(epics: true)
+      group.add_developer(epic.author)
+    end
+
     context 'epic notes' do
-      set(:group) { create(:group, :private) }
-      set(:epic) { create(:epic, group: group) }
       set(:note) { create(:note, project: nil, noteable: epic, note: '@mention referenced, @unsubscribed_mentioned and @outsider also') }
 
-      before(:all) do
-        create(:group_member, group: group, user: epic.author)
-        create(:group_member, group: group, user: note.author)
-      end
-
       before do
-        stub_licensed_features(epics: true)
         build_group_members(group)
 
         @u_custom_off = create_user_with_notification(:custom, 'custom_off', group)
@@ -289,11 +289,11 @@ describe EE::NotificationService, :mailer do
 
         update_custom_notification(:new_note, @u_guest_custom, resource: group)
         update_custom_notification(:new_note, @u_custom_global)
+        add_users_with_subscription(group, epic)
       end
 
       describe '#new_note' do
         it do
-          add_users_with_subscription(group, epic)
           reset_delivered_emails!
 
           expect(SentNotification).to receive(:record).with(epic, any_args).exactly(9).times
@@ -320,6 +320,59 @@ describe EE::NotificationService, :mailer do
         end
       end
     end
+
+    shared_examples 'epic notifications' do
+      let(:watcher) { create(:user) }
+      let(:participating) { create(:user) }
+      let(:other_user) { create(:user) }
+
+      before do
+        create_global_setting_for(watcher, :watch)
+        create_global_setting_for(participating, :participating)
+
+        group.add_developer(watcher)
+        group.add_developer(participating)
+        group.add_developer(other_user)
+
+        reset_delivered_emails!
+      end
+
+      it 'sends notification to watcher when no user participates' do
+        execute
+
+        should_email(watcher)
+        should_not_email(participating)
+        should_not_email(other_user)
+      end
+
+      it 'sends notification to watcher and a participator' do
+        epic.subscriptions.create(user: participating, subscribed: true)
+
+        execute
+
+        should_email(watcher)
+        should_email(participating)
+        should_not_email(other_user)
+      end
+    end
+
+    context 'close epic' do
+      let(:execute) { subject.close_epic(epic, epic.author) }
+
+      include_examples 'epic notifications'
+    end
+
+    context 'reopen epic' do
+      let(:execute) { subject.reopen_epic(epic, epic.author) }
+
+      include_examples 'epic notifications'
+    end
+
+    context 'new epic' do
+      let(:execute) { subject.new_epic(epic) }
+
+      include_examples 'epic notifications'
+    end
   end
 
   def build_group_members(group)

ee/spec/services/epics/close_service_spec.rb

@@ -50,6 +50,15 @@ describe Epics::CloseService do
             expect(note.note).to eq('closed')
             expect(note.system_note_metadata.action).to eq('closed')
           end
+
+          it 'notifies the subscribers' do
+            notification_service = double
+
+            expect(NotificationService).to receive(:new).and_return(notification_service)
+            expect(notification_service).to receive(:close_epic).with(epic, user)
+
+            subject.execute(epic)
+          end
         end
 
         context 'when trying to close a closed epic' do
@@ -72,6 +81,12 @@ describe Epics::CloseService do
           it 'does not create a system note' do
             expect { subject.execute(epic) }.not_to change { epic.notes.count }
           end
+
+          it 'does not send any emails' do
+            expect(NotificationService).not_to receive(:new)
+
+            subject.execute(epic)
+          end
         end
       end
 

ee/spec/services/epics/reopen_service_spec.rb

@@ -50,6 +50,15 @@ describe Epics::ReopenService do
             expect(note.note).to eq('opened')
             expect(note.system_note_metadata.action).to eq('opened')
           end
+
+          it 'notifies the subscribers' do
+            notification_service = double
+
+            expect(NotificationService).to receive(:new).and_return(notification_service)
+            expect(notification_service).to receive(:reopen_epic).with(epic, user)
+
+            subject.execute(epic)
+          end
         end
 
         context 'when trying to reopen an opened epic' do
@@ -72,6 +81,12 @@ describe Epics::ReopenService do
           it 'does not create a system note' do
             expect { subject.execute(epic) }.not_to change { epic.notes.count }
           end
+
+          it 'does not send any emails' do
+            expect(NotificationService).not_to receive(:new)
+
+            subject.execute(epic)
+          end
         end
       end