Merge branch '2451-fix-mentions-in-issue-updates' into 'master'

Send notification emails when users are newly mentioned in issue or MR edits

## What does this MR do?

Introduces "new mention in issue" and "new mention in MR" email notifications.  Editing a Mentionable title or description and adding a mention to a user who was not previously mentioned will now send them a notification email, following usual permissions for doing so.

## Why was this MR needed?

Issues & MRs may be edited to include mentions to new people. We don't currently send out email notifications of these edits to anyone, although they do create TODOs. This brings email notifications into parity with TODOs.

## What are the relevant issue numbers?

Closes #2451

See merge request !5800

CHANGELOG

@@ -34,6 +34,7 @@ v 8.11.0 (unreleased)
   - Fix awardable button mutuality loading spinners (ClemMakesApps)
   - Add support for using RequestStore within Sidekiq tasks via SIDEKIQ_REQUEST_STORE env variable
   - Optimize maximum user access level lookup in loading of notes
+  - Send notification emails to users newly mentioned in issue and MR edits !5800
   - Add "No one can push" as an option for protected branches. !5081
   - Improve performance of AutolinkFilter#text_parse by using XPath
   - Add experimental Redis Sentinel support !1877

app/mailers/emails/issues.rb

@@ -6,6 +6,11 @@ module Emails
       mail_new_thread(@issue, issue_thread_options(@issue.author_id, recipient_id))
     end
 
+    def new_mention_in_issue_email(recipient_id, issue_id, updated_by_user_id)
+      setup_issue_mail(issue_id, recipient_id)
+      mail_answer_thread(@issue, issue_thread_options(updated_by_user_id, recipient_id))
+    end
+
     def reassigned_issue_email(recipient_id, issue_id, previous_assignee_id, updated_by_user_id)
       setup_issue_mail(issue_id, recipient_id)
 

app/mailers/emails/merge_requests.rb

@@ -6,6 +6,11 @@ module Emails
       mail_new_thread(@merge_request, merge_request_thread_options(@merge_request.author_id, recipient_id))
     end
 
+    def new_mention_in_merge_request_email(recipient_id, merge_request_id, updated_by_user_id)
+      setup_merge_request_mail(merge_request_id, recipient_id)
+      mail_answer_thread(@merge_request, merge_request_thread_options(updated_by_user_id, recipient_id))
+    end
+
     def reassigned_merge_request_email(recipient_id, merge_request_id, previous_assignee_id, updated_by_user_id)
       setup_merge_request_mail(merge_request_id, recipient_id)
 

app/services/issuable_base_service.rb

@@ -104,11 +104,12 @@ class IssuableBaseService < BaseService
     change_subscription(issuable)
     filter_params
     old_labels = issuable.labels.to_a
+    old_mentioned_users = issuable.mentioned_users.to_a
 
     if params.present? && update_issuable(issuable, params)
       issuable.reset_events_cache
       handle_common_system_notes(issuable, old_labels: old_labels)
-      handle_changes(issuable, old_labels: old_labels)
+      handle_changes(issuable, old_labels: old_labels, old_mentioned_users: old_mentioned_users)
       issuable.create_new_cross_references!(current_user)
       execute_hooks(issuable, 'update')
     end

app/services/issues/update_service.rb

@@ -4,7 +4,7 @@ module Issues
       update(issue)
     end
 
-    def handle_changes(issue, old_labels: [])
+    def handle_changes(issue, old_labels: [], old_mentioned_users: [])
       if has_changes?(issue, old_labels: old_labels)
         todo_service.mark_pending_todos_as_done(issue, current_user)
       end
@@ -32,6 +32,11 @@ module Issues
       if added_labels.present?
         notification_service.relabeled_issue(issue, added_labels, current_user)
       end
+
+      added_mentions = issue.mentioned_users - old_mentioned_users
+      if added_mentions.present?
+        notification_service.new_mentions_in_issue(issue, added_mentions, current_user)
+      end
     end
 
     def reopen_service

app/services/merge_requests/update_service.rb

@@ -16,7 +16,7 @@ module MergeRequests
       update(merge_request)
     end
 
-    def handle_changes(merge_request, old_labels: [])
+    def handle_changes(merge_request, old_labels: [], old_mentioned_users: [])
       if has_changes?(merge_request, old_labels: old_labels)
         todo_service.mark_pending_todos_as_done(merge_request, current_user)
       end
@@ -55,6 +55,15 @@ module MergeRequests
           current_user
         )
       end
+
+      added_mentions = merge_request.mentioned_users - old_mentioned_users
+      if added_mentions.present?
+        notification_service.new_mentions_in_merge_request(
+          merge_request,
+          added_mentions,
+          current_user
+        )
+      end
     end
 
     def reopen_service

app/services/notification_service.rb

@@ -35,6 +35,20 @@ class NotificationService
     new_resource_email(issue, issue.project, :new_issue_email)
   end
 
+  # When issue text is updated, we should send an email to:
+  #
+  #  * newly mentioned project team members with notification level higher than Participating
+  #
+  def new_mentions_in_issue(issue, new_mentioned_users, current_user)
+    new_mentions_in_resource_email(
+      issue,
+      issue.project,
+      new_mentioned_users,
+      current_user,
+      :new_mention_in_issue_email
+    )
+  end
+
   # When we close an issue we should send an email to:
   #
   #  * issue author if their notification level is not Disabled
@@ -75,6 +89,20 @@ class NotificationService
     new_resource_email(merge_request, merge_request.target_project, :new_merge_request_email)
   end
 
+  # When merge request text is updated, we should send an email to:
+  #
+  #  * newly mentioned project team members with notification level higher than Participating
+  #
+  def new_mentions_in_merge_request(merge_request, new_mentioned_users, current_user)
+    new_mentions_in_resource_email(
+      merge_request,
+      merge_request.target_project,
+      new_mentioned_users,
+      current_user,
+      :new_mention_in_merge_request_email
+    )
+  end
+
   # When we reassign a merge_request we should send an email to:
   #
   #  * merge_request old assignee if their notification level is not Disabled
@@ -471,6 +499,15 @@ class NotificationService
     end
   end
 
+  def new_mentions_in_resource_email(target, project, new_mentioned_users, current_user, method)
+    recipients = build_recipients(target, project, current_user, action: "new")
+    recipients = recipients & new_mentioned_users
+
+    recipients.each do |recipient|
+      mailer.send(method, recipient.id, target.id, current_user.id).deliver_later
+    end
+  end
+
   def close_resource_email(target, project, current_user, method)
     action = method == :merged_merge_request_email ? "merge" : "close"
     recipients = build_recipients(target, project, current_user, action: action)

app/views/notify/new_mention_in_issue_email.html.haml

+%p
+  You have been mentioned in an issue.
+
+- if current_application_settings.email_author_in_body
+  %div
+    #{link_to @issue.author_name, user_url(@issue.author)} wrote:
+-if @issue.description
+  = markdown(@issue.description, pipeline: :email, author: @issue.author)
+
+- if @issue.assignee_id.present?
+  %p
+    Assignee: #{@issue.assignee_name}

app/views/notify/new_mention_in_issue_email.text.erb

+You have been mentioned in an issue.
+
+Issue <%= @issue.iid %>: <%= url_for(namespace_project_issue_url(@issue.project.namespace, @issue.project, @issue)) %>
+Author:    <%= @issue.author_name %>
+Assignee:  <%= @issue.assignee_name %>
+
+<%= @issue.description %>

app/views/notify/new_mention_in_merge_request_email.html.haml

+%p
+  You have been mentioned in Merge Request #{@merge_request.to_reference}
+
+- if current_application_settings.email_author_in_body
+  %div
+    #{link_to @merge_request.author_name, user_url(@merge_request.author)} wrote:
+%p.details
+  != merge_path_description(@merge_request, '→')
+
+- if @merge_request.assignee_id.present?
+  %p
+    Assignee: #{@merge_request.author_name} → #{@merge_request.assignee_name}
+
+-if @merge_request.description
+  = markdown(@merge_request.description, pipeline: :email, author: @merge_request.author)

app/views/notify/new_mention_in_merge_request_email.text.erb

+You have been mentioned in Merge Request <%= @merge_request.to_reference %>
+
+<%= url_for(namespace_project_merge_request_url(@merge_request.target_project.namespace, @merge_request.target_project, @merge_request)) %>
+
+<%= merge_path_description(@merge_request, 'to') %>
+Author:    <%= @merge_request.author_name %>
+Assignee:  <%= @merge_request.assignee_name %>
+
+<%= @merge_request.description %>

doc/workflow/notifications.md

@@ -67,7 +67,7 @@ In all of the below cases, the notification will be sent to:
 - Participants:
   - the author and assignee of the issue/merge request
   - authors of comments on the issue/merge request
-  - anyone mentioned by `@username` in the issue/merge request description
+  - anyone mentioned by `@username` in the issue/merge request title or description
   - anyone mentioned by `@username` in any of the comments on the issue/merge request
 
     ...with notification level "Participating" or higher
@@ -89,6 +89,11 @@ In all of the below cases, the notification will be sent to:
 | Merge merge request    | |
 | New comment            | The above, plus anyone mentioned by `@username` in the comment, with notification level "Mention" or higher |
 
+
+In addition, if the title or description of an Issue or Merge Request is
+changed, notifications will be sent to any **new** mentions by `@username` as
+if they had been mentioned in the original text.
+
 You won't receive notifications for Issues, Merge Requests or Milestones
 created by yourself. You will only receive automatic notifications when
 somebody else comments or adds changes to the ones that you've created or

spec/services/issues/update_service_spec.rb

@@ -319,5 +319,10 @@ describe Issues::UpdateService, services: true do
         end
       end
     end
+
+    context 'updating mentions' do
+      let(:mentionable) { issue }
+      include_examples 'updating mentions', Issues::UpdateService
+    end
   end
 end

spec/services/merge_requests/update_service_spec.rb

@@ -226,6 +226,11 @@ describe MergeRequests::UpdateService, services: true do
       end
     end
 
+    context 'updating mentions' do
+      let(:mentionable) { merge_request }
+      include_examples 'updating mentions', MergeRequests::UpdateService
+    end
+
     context 'when MergeRequest has tasks' do
       before { update_merge_request({ description: "- [ ] Task 1\n- [ ] Task 2" }) }
 

spec/services/notification_service_spec.rb

@@ -9,6 +9,28 @@ describe NotificationService, services: true do
     end
   end
 
+  shared_examples 'notifications for new mentions' do
+    def send_notifications(*new_mentions)
+      reset_delivered_emails!
+      notification.send(notification_method, mentionable, new_mentions, @u_disabled)
+    end
+
+    it 'sends no emails when no new mentions are present' do
+      send_notifications
+      expect(ActionMailer::Base.deliveries).to be_empty
+    end
+
+    it 'emails new mentions with a watch level higher than participant' do
+      send_notifications(@u_watcher, @u_participant_mentioned, @u_custom_global)
+      should_only_email(@u_watcher, @u_participant_mentioned, @u_custom_global)
+    end
+
+    it 'does not email new mentions with a watch level equal to or less than participant' do
+      send_notifications(@u_participating, @u_mentioned)
+      expect(ActionMailer::Base.deliveries).to be_empty
+    end
+  end
+
   describe 'Keys' do
     describe '#new_key' do
       let!(:key) { create(:personal_key) }
@@ -399,6 +421,13 @@ describe NotificationService, services: true do
       end
     end
 
+    describe '#new_mentions_in_issue' do
+      let(:notification_method) { :new_mentions_in_issue }
+      let(:mentionable) { issue }
+
+      include_examples 'notifications for new mentions'
+    end
+
     describe '#reassigned_issue' do
       before do
         update_custom_notification(:reassign_issue, @u_guest_custom, project)
@@ -700,6 +729,8 @@ describe NotificationService, services: true do
     before do
       build_team(merge_request.target_project)
       add_users_with_subscription(merge_request.target_project, merge_request)
+      update_custom_notification(:new_merge_request, @u_guest_custom, project)
+      update_custom_notification(:new_merge_request, @u_custom_global)
       ActionMailer::Base.deliveries.clear
     end
 
@@ -763,6 +794,13 @@ describe NotificationService, services: true do
       end
     end
 
+    describe '#new_mentions_in_merge_request' do
+      let(:notification_method) { :new_mentions_in_merge_request }
+      let(:mentionable) { merge_request }
+
+      include_examples 'notifications for new mentions'
+    end
+
     describe '#reassigned_merge_request' do
       before do
         update_custom_notification(:reassign_merge_request, @u_guest_custom, project)

spec/support/email_helpers.rb

@@ -3,6 +3,16 @@ module EmailHelpers
     ActionMailer::Base.deliveries.map(&:to).flatten.count(user.email) == 1
   end
 
+  def reset_delivered_emails!
+    ActionMailer::Base.deliveries.clear
+  end
+
+  def should_only_email(*users)
+    users.each {|user| should_email(user) }
+    recipients = ActionMailer::Base.deliveries.flat_map(&:to)
+    expect(recipients.count).to eq(users.count)
+  end
+
   def should_email(user)
     expect(sent_to_user?(user)).to be_truthy
   end

spec/support/updating_mentions_shared_examples.rb

+RSpec.shared_examples 'updating mentions' do |service_class|
+  let(:mentioned_user) { create(:user) }
+  let(:service_class) { service_class }
+
+  before { project.team << [mentioned_user, :developer] }
+
+  def update_mentionable(opts)
+    reset_delivered_emails!
+
+    perform_enqueued_jobs do
+      service_class.new(project, user, opts).execute(mentionable)
+    end
+
+    mentionable.reload
+  end
+
+  context 'in title' do
+    before { update_mentionable(title: mentioned_user.to_reference) }
+
+    it 'emails only the newly-mentioned user' do
+      should_only_email(mentioned_user)
+    end
+  end
+
+  context 'in description' do
+    before { update_mentionable(description: mentioned_user.to_reference) }
+
+    it 'emails only the newly-mentioned user' do
+      should_only_email(mentioned_user)
+    end
+  end
+end