3 files changed, 48 insertions, 0 deletions
diff --git a/app/services/merge_requests/remove_approval_service.rb b/app/services/merge_requests/remove_approval_service.rb
new file mode 100644
index 00000000000..8ae6651e59b
--- /dev/null
+++ b/app/services/merge_requests/remove_approval_service.rb
@@ -0,0 +1,31 @@
+module MergeRequests
+  class RemoveApprovalService < MergeRequests::BaseService
+    def execute(merge_request)
+      # paranoid protection against running wrong deletes
+      return unless merge_request.id && current_user.id
+
+      approval = merge_request.approvals.where(user: current_user)
+
+      currently_approved = merge_request.approved?
+
+      if approval.destroy_all
+        # bust the cache here, otherwise will show results from
+        # before the deletion
+        merge_request.approvals(true)
+
+        create_note(merge_request)
+
+        if currently_approved
+          notification_service.unapprove_mr(merge_request, current_user)
+          execute_hooks(merge_request, 'unapproved')
+        end
+      end
+    end
+
+    private
+
+    def create_note(merge_request)
+      SystemNoteService.unapprove_mr(merge_request, current_user)
+    end
+  end
+end
diff --git a/app/services/notification_service.rb b/app/services/notification_service.rb
index 89396156d0c..34982ff4167 100644
--- a/app/services/notification_service.rb
+++ b/app/services/notification_service.rb
@@ -162,6 +162,10 @@ class NotificationService
     approve_mr_email(merge_request, merge_request.target_project, current_user)
   end
 
+  def unapprove_mr(merge_request, current_user)
+    unapprove_mr_email(merge_request, merge_request.target_project, current_user)
+  end
+
   def resolve_all_discussions(merge_request, current_user)
     recipients = build_recipients(merge_request, merge_request.target_project, current_user, action: "resolve_all_discussions")
 
@@ -608,6 +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
diff --git a/app/services/system_note_service.rb b/app/services/system_note_service.rb
index c6c9d006809..9e6a3c8f31d 100644
--- a/app/services/system_note_service.rb
+++ b/app/services/system_note_service.rb
@@ -474,6 +474,11 @@ module SystemNoteService
     create_note(noteable: noteable, project: noteable.project, author: user, note: body)
   end
 
+  def unapprove_mr(noteable, user)
+    body = "Unapproved this merge request"
+    create_note(noteable: noteable, project: noteable.project, author: user, note: body)
+  end
+
   private
 
   def notes_for_mentioner(mentioner, noteable, notes)