1 files changed, 30 insertions, 0 deletions
diff --git a/rubocop/cop/performance/active_record_subtransactions.rb b/rubocop/cop/performance/active_record_subtransactions.rb
new file mode 100644
index 00000000000..a550b558e52
--- /dev/null
+++ b/rubocop/cop/performance/active_record_subtransactions.rb
@@ -0,0 +1,30 @@
+# frozen_string_literal: true
+
+module RuboCop
+  module Cop
+    module Performance
+      class ActiveRecordSubtransactions < RuboCop::Cop::Cop
+        MSG = 'Subtransactions should not be used. ' \
+          'For more information see: https://gitlab.com/gitlab-org/gitlab/-/issues/338346'
+
+        def_node_matcher :match_transaction_with_options, <<~PATTERN
+          (send _ :transaction (hash $...))
+        PATTERN
+
+        def_node_matcher :subtransaction_option?, <<~PATTERN
+          (pair (:sym :requires_new) (true))
+        PATTERN
+
+        def on_send(node)
+          match_transaction_with_options(node) do |option_nodes|
+            option_nodes.each do |option_node|
+              next unless subtransaction_option?(option_node)
+
+              add_offense(option_node)
+            end
+          end
+        end
+      end
+    end
+  end
+end