1 files changed, 24 insertions, 0 deletions

diff --git a/app/services/issues/duplicate_service.rb b/app/services/issues/duplicate_service.rb
new file mode 100644
index 00000000000..5c0854e664d
--- /dev/null
+++ b/app/services/issues/duplicate_service.rb
@@ -0,0 +1,24 @@
+module Issues
+  class DuplicateService < Issues::BaseService
+    def execute(duplicate_issue, canonical_issue)
+      return if canonical_issue == duplicate_issue
+      return unless can?(current_user, :update_issue, duplicate_issue)
+      return unless can?(current_user, :create_note, canonical_issue)
+
+      create_issue_duplicate_note(duplicate_issue, canonical_issue)
+      create_issue_canonical_note(canonical_issue, duplicate_issue)
+
+      close_service.new(project, current_user, {}).execute(duplicate_issue)
+    end
+
+    private
+
+    def create_issue_duplicate_note(duplicate_issue, canonical_issue)
+      SystemNoteService.mark_duplicate_issue(duplicate_issue, duplicate_issue.project, current_user, canonical_issue)
+    end
+
+    def create_issue_canonical_note(canonical_issue, duplicate_issue)
+      SystemNoteService.mark_canonical_issue_of_duplicate(canonical_issue, canonical_issue.project, current_user, duplicate_issue)
+    end
+  end
+end