Adds system note when external participants have been added from CC

Also adds an abstraction IssueEmailParticipants::CreateService
and refactors the /invite_email quick action to use this.

app/services/issue_email_participants/create_service.rb

+# frozen_string_literal: true
+
+module IssueEmailParticipants
+  class CreateService < ::BaseProjectService
+    MAX_NUMBER_OF_EMAILS = 6
+
+    attr_reader :target, :emails
+
+    def initialize(target:, current_user:, emails:)
+      super(project: target.project, current_user: current_user)
+
+      @target = target
+      @emails = emails
+    end
+
+    def execute
+      return error_feature_flag unless Feature.enabled?(:issue_email_participants, target.project)
+      return error_underprivileged unless current_user.can?(:"admin_#{target.to_ability_name}", target)
+      return error_no_participants unless emails.present?
+
+      added_emails = add_participants(deduplicate_and_limit_emails)
+
+      if added_emails.any?
+        message = add_system_note(added_emails)
+        ServiceResponse.success(message: message.upcase_first << ".")
+      else
+        error_no_participants
+      end
+    end
+
+    private
+
+    def deduplicate_and_limit_emails
+      existing_emails = target.email_participants_emails_downcase
+      # Compare downcase versions, but use the original email
+      emails.index_by { |email| [email.downcase, email] }.excluding(*existing_emails).each_value
+        .first(MAX_NUMBER_OF_EMAILS)
+    end
+
+    def add_participants(emails_to_add)
+      added_emails = []
+      emails_to_add.each do |email|
+        new_participant = target.issue_email_participants.create(email: email)
+        added_emails << email if new_participant.persisted?
+      end
+
+      added_emails
+    end
+
+    def add_system_note(added_emails)
+      message = format(_("added %{emails}"), emails: added_emails.to_sentence)
+      ::SystemNoteService.add_email_participants(target, project, current_user, message)
+
+      message
+    end
+
+    def error(message)
+      ServiceResponse.error(message: message)
+    end
+
+    def error_feature_flag
+      # Don't translate feature flag error because it's temporary.
+      error("Feature flag issue_email_participants is not enabled for this project.")
+    end
+
+    def error_underprivileged
+      error(_("You don't have permission to add email participants."))
+    end
+
+    def error_no_participants
+      error(_("No email participants were added. Either none were provided, or they already exist."))
+    end
+  end
+end

lib/gitlab/email/handler/service_desk_handler.rb

@@ -230,6 +230,9 @@ def author
         def add_email_participants
           return if reply_email? && !Feature.enabled?(:issue_email_participants, @issue.project)
 
+          # Migrate this to ::IssueEmailParticipants::CreateService once the
+          # feature flag issue_email_participants has been enabled globally
+          # or removed: https://gitlab.com/gitlab-org/gitlab/-/merge_requests/137147#note_1652104416
           @issue.issue_email_participants.create(email: from_address)
 
           add_external_participants_from_cc
@@ -239,11 +242,11 @@ def add_external_participants_from_cc
           return if project.service_desk_setting.nil?
           return unless project.service_desk_setting.add_external_participants_from_cc?
 
-          cc_addresses.each do |email|
-            next if service_desk_addresses.include?(email)
-
-            @issue.issue_email_participants.create!(email: email)
-          end
+          ::IssueEmailParticipants::CreateService.new(
+            target: @issue,
+            current_user: Users::Internal.support_bot,
+            emails: cc_addresses.excluding(service_desk_addresses)
+          ).execute
         end
 
         def service_desk_addresses

lib/gitlab/quick_actions/issue_actions.rb

@@ -230,24 +230,13 @@ module IssueActions
             current_user.can?(:"admin_#{quick_action_target.to_ability_name}", quick_action_target)
         end
         command :invite_email do |emails = ""|
-          MAX_NUMBER_OF_EMAILS = 6
+          response = ::IssueEmailParticipants::CreateService.new(
+            target: quick_action_target,
+            current_user: current_user,
+            emails: emails.split(' ')
+          ).execute
 
-          existing_emails = quick_action_target.email_participants_emails_downcase
-          emails_to_add = emails.split(' ').index_by { |email| [email.downcase, email] }.except(*existing_emails).each_value.first(MAX_NUMBER_OF_EMAILS)
-          added_emails = []
-
-          emails_to_add.each do |email|
-            new_participant = quick_action_target.issue_email_participants.create(email: email)
-            added_emails << email if new_participant.persisted?
-          end
-
-          if added_emails.any?
-            message = _("added %{emails}") % { emails: added_emails.to_sentence }
-            SystemNoteService.add_email_participants(quick_action_target, quick_action_target.project, current_user, message)
-            @execution_message[:invite_email] = message.upcase_first << "."
-          else
-            @execution_message[:invite_email] = _("No email participants were added. Either none were provided, or they already exist.")
-          end
+          @execution_message[:invite_email] = response.message
         end
 
         desc { _('Promote issue to incident') }

locale/gitlab.pot

@@ -55554,6 +55554,9 @@ msgstr ""
 msgid "You don't have any recent searches"
 msgstr ""
+msgid "You don't have permission to add email participants."
+msgstr ""
+
 msgid "You don't have permission to approve this deployment. Contact the project or group owner for help."
 msgstr ""

spec/services/issue_email_participants/create_service_spec.rb

+# frozen_string_literal: true
+
+require 'spec_helper'
+
+RSpec.describe IssueEmailParticipants::CreateService, feature_category: :service_desk do
+  shared_examples 'a successful service execution' do
+    it 'creates new participants', :aggregate_failures do
+      expect(response).to be_success
+
+      issue.reset
+      note = issue.notes.last
+      expect(note.system?).to be true
+      expect(note.author).to eq(user)
+
+      participants_emails = issue.email_participants_emails_downcase
+
+      expected_emails.each do |email|
+        expect(participants_emails).to include(email)
+        expect(response.message).to include(email)
+        expect(note.note).to include(email)
+      end
+    end
+  end
+
+  shared_examples 'a failed service execution' do
+    it 'returns error ServiceResponse with message', :aggregate_failures do
+      expect(response).to be_error
+      expect(response.message).to eq(error_message)
+    end
+  end
+
+  describe '#execute' do
+    let_it_be_with_reload(:project) { create(:project) }
+    let_it_be(:user) { create(:user) }
+    let_it_be(:issue) { create(:issue, project: project) }
+
+    let(:emails) { nil }
+    let(:service) { described_class.new(target: issue, current_user: user, emails: emails) }
+    let(:expected_emails) { emails }
+
+    let(:error_feature_flag) { "Feature flag issue_email_participants is not enabled for this project." }
+    let(:error_underprivileged) { _("You don't have permission to add email participants.") }
+    let(:error_no_participants) do
+      _("No email participants were added. Either none were provided, or they already exist.")
+    end
+
+    subject(:response) { service.execute }
+
+    context 'when the user is not a project member' do
+      let(:error_message) { error_underprivileged }
+
+      it_behaves_like 'a failed service execution'
+    end
+
+    context 'when user has reporter role in project' do
+      before_all do
+        project.add_reporter(user)
+      end
+
+      context 'when no emails are provided' do
+        let(:error_message) { error_no_participants }
+
+        it_behaves_like 'a failed service execution'
+      end
+
+      context 'when one email is provided' do
+        let(:emails) { ['user@example.com'] }
+
+        it_behaves_like 'a successful service execution'
+
+        context 'when email is already a participant of the issue' do
+          let(:error_message) { error_no_participants }
+
+          before do
+            issue.issue_email_participants.create!(email: emails.first)
+          end
+
+          it_behaves_like 'a failed service execution'
+
+          context 'when email is formatted in a different case' do
+            let(:emails) { ['USER@example.com'] }
+
+            it_behaves_like 'a failed service execution'
+          end
+        end
+      end
+
+      context 'when multiple emails are provided' do
+        let(:emails) { ['user@example.com', 'user2@example.com'] }
+
+        it_behaves_like 'a successful service execution'
+
+        context 'when duplicate email provided' do
+          let(:emails) { ['user@example.com', 'user@example.com'] }
+          let(:expected_emails) { emails[...-1] }
+
+          it_behaves_like 'a successful service execution'
+        end
+
+        context 'when an email is already a participant of the issue' do
+          let(:expected_emails) { emails[1...] }
+
+          before do
+            issue.issue_email_participants.create!(email: emails.first)
+          end
+
+          it_behaves_like 'a successful service execution'
+        end
+      end
+
+      context 'when more than the allowed number of emails a re provided' do
+        let(:emails) { (1..7).map { |i| "user#{i}@example.com" } }
+
+        let(:expected_emails) { emails[...-1] }
+
+        it_behaves_like 'a successful service execution'
+      end
+    end
+
+    context 'when feature flag issue_email_participants is disabled' do
+      let(:error_message) { error_feature_flag }
+
+      before do
+        stub_feature_flags(issue_email_participants: false)
+      end
+
+      it_behaves_like 'a failed service execution'
+    end
+  end
+end