class RuboCop::Cop::Rails::UniqueValidationWithoutIndex

def on_send(node)
  return unless schema
  return unless (uniqueness_part = uniqueness_part(node))
  return if uniqueness_part.falsey_literal? || condition_part?(node, uniqueness_part)
  klass, table, names = find_schema_information(node, uniqueness_part)
  return unless names
  return if with_index?(klass, table, names)
  add_offense(node)
end