class ReactOnRails::Dev::ServerManager

def find_port_pids(port)
  stdout, _status = Open3.capture2("lsof", "-ti", ":#{port}", err: File::NULL)
  stdout.split("\n").map(&:to_i).reject { |pid| pid == Process.pid }
rescue StandardError
  # lsof command not found or other error (permission denied, etc.)
  []
end