1 files changed, 33 insertions, 0 deletions
diff --git a/lib/gitlab/background_migration/backfill_draft_status_on_merge_requests.rb b/lib/gitlab/background_migration/backfill_draft_status_on_merge_requests.rb
new file mode 100644
index 00000000000..a0d0791b6af
--- /dev/null
+++ b/lib/gitlab/background_migration/backfill_draft_status_on_merge_requests.rb
@@ -0,0 +1,33 @@
+# frozen_string_literal: true
+
+module Gitlab
+  module BackgroundMigration
+    # Backfill draft column on open merge requests based on regex parsing of
+    #   their titles.
+    #
+    class BackfillDraftStatusOnMergeRequests
+      # Migration only version of MergeRequest table
+      class MergeRequest < ActiveRecord::Base
+        include EachBatch
+
+        self.table_name = 'merge_requests'
+
+        def self.eligible
+          where(state_id: 1)
+            .where(draft: false)
+            .where("title ~* ?", '^\\[draft\\]|\\(draft\\)|draft:|draft|\\[WIP\\]|WIP:|WIP')
+        end
+      end
+
+      def perform(start_id, end_id)
+        eligible_mrs = MergeRequest.eligible.where(id: start_id..end_id).pluck(:id)
+
+        return if eligible_mrs.empty?
+
+        eligible_mrs.each_slice(10) do |slice|
+          MergeRequest.where(id: slice).update_all(draft: true)
+        end
+      end
+    end
+  end
+end