[#94] Backend

https://project.mdnd-it.cc/work_packages/94

SerpentRace_Backend/node_modules/engine.io-parser/build/esm/commons.js

@@ -0,0 +1,14 @@
+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 };