Send unapproval emails for MRs

app/mailers/emails/merge_requests.rb

@@ -54,11 +54,20 @@ module Emails
       mail_answer_thread(@merge_request, merge_request_thread_options(updated_by_user_id, recipient_id))
     end
 
-    def approved_merge_request_email(recipient_id, merge_request_id, updated_by_user_id)
+    def approved_merge_request_email(recipient_id, merge_request_id, approved_by_user_id)
       setup_merge_request_mail(merge_request_id, recipient_id)
 
+      @approved_by = User.find(approved_by_user_id)
       @approved_by_users = @merge_request.approved_by_users.map(&:name)
-      mail_answer_thread(@merge_request, merge_request_thread_options(updated_by_user_id, recipient_id))
+      mail_answer_thread(@merge_request, merge_request_thread_options(approved_by_user_id, recipient_id))
+    end
+
+    def unapproved_merge_request_email(recipient_id, merge_request_id, unapproved_by_user_id)
+      setup_merge_request_mail(merge_request_id, recipient_id)
+
+      @unapproved_by = User.find(approved_by_user_id)
+      @unapproved_by_users = @merge_request.approved_by_users.map(&:name)
+      mail_answer_thread(@merge_request, merge_request_thread_options(approved_by_user_id, recipient_id))
     end
 
     def resolved_all_discussions_email(recipient_id, merge_request_id, resolved_by_user_id)

app/services/notification_service.rb

@@ -163,7 +163,7 @@ class NotificationService
   end
 
   def unapprove_mr(merge_request, current_user)
-    # TODO: send unapproval email
+    unapprove_mr_email(merge_request, merge_request.target_project, current_user)
   end
 
   def resolve_all_discussions(merge_request, current_user)
@@ -612,6 +612,14 @@ class NotificationService
     end
   end
 
+  def unapprove_mr_email(merge_request, project, current_user)
+    recipients = build_recipients(merge_request, project, current_user)
+
+    recipients.each do |recipient|
+      mailer.unapproved_merge_request_email(recipient.id, merge_request.id, current_user.id).deliver_later
+    end
+  end
+
   def add_mr_approvers_email(merge_request, approvers, current_user)
     approvers.each do |approver|
       recipient = approver.user

spec/mailers/notify_spec.rb

@@ -405,6 +405,44 @@ describe Notify do
           end
         end
 
+        describe 'that are unapproved' do
+          let(:last_unapprover) { create(:user) }
+          subject { Notify.unapproved_merge_request_email(recipient.id, merge_request.id, last_unapprover.id) }
+
+          before do
+            merge_request.approvals.create(user: merge_request.assignee)
+          end
+
+          it_behaves_like 'a multiple recipients email'
+          it_behaves_like 'an answer to an existing thread with reply-by-email enabled' do
+            let(:model) { merge_request }
+          end
+          it_behaves_like 'it should show Gmail Actions View Merge request link'
+          it_behaves_like 'an unsubscribeable thread'
+
+          it 'is sent as the last unapprover' do
+            sender = subject.header[:from].addrs[0]
+            expect(sender.display_name).to eq(last_unapprover.name)
+            expect(sender.address).to eq(gitlab_sender)
+          end
+
+          it 'has the correct subject' do
+            is_expected.to have_subject /#{merge_request.title} \(#{merge_request.to_reference}\)/
+          end
+
+          it 'contains the new status' do
+            is_expected.to have_body_text /unapproved/i
+          end
+
+          it 'contains a link to the merge request' do
+            is_expected.to have_body_text /#{namespace_project_merge_request_path project.namespace, project, merge_request}/
+          end
+
+          it 'contains the names of all of the approvers' do
+            is_expected.to have_body_text /#{merge_request.assignee.name}/
+          end
+        end
+
         describe 'that are merged' do
           subject { Notify.merged_merge_request_email(recipient.id, merge_request.id, merge_author.id) }