Add reviewers detail to add merge request approver email

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

 - if Gitlab::CurrentSettings.email_author_in_body
   %div
     #{link_to @updated_by.name, user_url(@updated_by)} added you as an approver for:
-%p.details
-  = merge_path_description(@merge_request, '→')
-
-- if @merge_request.assignees.any?
-  %p
-    - label = assignees_label(@merge_request, include_value: false)
-    - author_name = sanitize_name(@merge_request.author_name)
-    - assignee_list = sanitize_name(@merge_request.assignee_list)
-
-    "#{label}: #{author_name} → #{assignee_list}"
-
-= render_if_exists 'notify/merge_request_approvers', presenter: @mr_presenter
+%p
+  .details
+    = merge_path_description(@merge_request, '→')
+  .author
+    Author: #{sanitize_name(@merge_request.author_name)}
+  .assignee
+    = assignees_label(@merge_request)
+  .reviewer
+    = reviewers_label(@merge_request)
+  .approvers
+    = render 'notify/merge_request_approvers', presenter: @mr_presenter
 
 - if @merge_request.description
-  = markdown(@merge_request.description, pipeline: :email, author: @merge_request.author)
+  %div
+    = markdown(@merge_request.description, pipeline: :email, author: @merge_request.author)

ee/app/views/notify/add_merge_request_approver_email.text.erb

@@ -5,4 +5,5 @@
 <%= merge_path_description(@merge_request, 'to') %>
 Author:    <%= sanitize_name(@merge_request.author_name) %>
 <%= assignees_label(@merge_request) %>
+<%= reviewers_label(@merge_request) %>
 <%= render_if_exists 'notify/merge_request_approvers', presenter: @mr_presenter %>

ee/changelogs/unreleased/300750-add-missing-reviewers-information-to-add_merge_request_approver_em.yml

+---
+title: Add reviewers detail to add merge request approver email
+merge_request: 56466
+author:
+type: added

ee/spec/mailers/ee/emails/merge_requests_spec.rb

@@ -17,18 +17,32 @@ RSpec.describe EE::Emails::MergeRequests do
     subject { Notify.add_merge_request_approver_email(recipient.id, merge_request.id, current_user.id) }
 
     context 'when email_author_in_body is set' do
-      it 'includes the name of the person who added the approver' do
+      it 'has the correct body with the name of the person who added the approver' do
         stub_application_setting(email_author_in_body: true)
 
-        expect(subject).to have_body_text(current_user.name)
+        aggregate_failures do
+          is_expected.to have_body_text(current_user.name)
+          is_expected.to have_body_text('added you as an approver')
+          is_expected.to have_text_part_content(assignee.name)
+          is_expected.to have_html_part_content(assignee.name)
+          is_expected.to have_text_part_content(reviewer.name)
+          is_expected.to have_html_part_content(reviewer.name)
+        end
       end
     end
 
     context 'when email_author_in_body is not set' do
-      it 'does not include the name of the person who added the approver' do
+      it 'has the correct body without the name of the person who added the approver' do
         stub_application_setting(email_author_in_body: false)
 
-        expect(subject).not_to have_body_text(current_user.name)
+        aggregate_failures do
+          is_expected.not_to have_body_text(current_user.name)
+          is_expected.not_to have_body_text('added you as an approver')
+          is_expected.to have_text_part_content(assignee.name)
+          is_expected.to have_html_part_content(assignee.name)
+          is_expected.to have_text_part_content(reviewer.name)
+          is_expected.to have_html_part_content(reviewer.name)
+        end
       end
     end
   end