const PACKET_TYPES = Object.create(null); // no Map = no polyfill PACKET_TYPES["open"] = "0"; PACKET_TYPES["close"] = "1"; PACKET_TYPES["ping"] = "2"; PACKET_TYPES["pong"] = "3"; PACKET_TYPES["message"] = "4"; PACKET_TYPES["upgrade"] = "5"; PACKET_TYPES["noop"] = "6"; const PACKET_TYPES_REVERSE = Object.create(null); Object.keys(PACKET_TYPES).forEach(key => { PACKET_TYPES_REVERSE[PACKET_TYPES[key]] = key; }); const ERROR_PACKET = { type: "error", data: "parser error" }; export { PACKET_TYPES, PACKET_TYPES_REVERSE, ERROR_PACKET };