websocket.js

import { randomBytes } from "node:crypto";
import { request as httpRequest } from "node:http";
import { request as httpsRequest } from "node:https";

const DEFAULT_PORT = 443;
const SEC_WEBSOCKET_VERSION = 13;

class WebSocket extends EventTarget {
  constructor(url, protocols) {
    super();

    this.protocol = protocols;
    this.url = url;

    this.#connect();
  }

  static {
    this.CONNECTING = this.prototype.CONNECTING = 0;
    this.OPEN = this.prototype.OPEN = 1;
    this.CLOSING = this.prototype.CLOSING = 2;
    this.CLOSED = this.prototype.CLOSED = 3;
  }

  #connect() {
    const url = new URL(this.url);

    const isSecure = url.protocol === "wss:" || url.protocol === "https:";
    const request = isSecure ? httpsRequest : httpRequest;

    const headers = {
      "Connection": "Upgrade",
      "Sec-WebSocket-Key": randomBytes(16).toString("base64"),
      "Sec-WebSocket-Version": SEC_WEBSOCKET_VERSION,
      "Upgrade": "websocket",
    };

    const req = request({
      defaultPort: DEFAULT_PORT,
      port: url.port ?? DEFAULT_PORT,
      headers,
      host: url.host,
      path: url.pathname + url.search,
    });

    req.end();

    req.on("upgrade", (_, socket) => {
      // socket.setEncoding("utf8");

      socket.on("data", (data) => {
        const [a, b] = data;

        const fin = a & 0x80;
        const rsv1 = a & 0x40;
        const rsv2 = a & 0x20;
        const rsv3 = a & 0x10;
        const opcode = a & 0x0F;
        const mask = b & 0x80;

        const payloadLen = b & 0x7F;
      });
    });
  }
}

new WebSocket("wss://gateway.discord.gg");