class RuboCop::Cop::Minitest::TestMethodName

def on_class(class_node)
  return unless test_class?(class_node)
  class_def_nodes(class_node).each do |node|
    next unless offense?(node)
    test_method_name = node.loc.name
    add_offense(test_method_name) do |corrector|
      corrector.replace(test_method_name, "test_#{node.method_name}")
    end
  end
end