Non-tested class for Twitch API WebSocket

TwitchWebSocket.js

class TwitchWebSocket {
  constructor() {
    this.lastPingTimestamp = null;
    this.lastPongTimestamp = null;
    this.pingInterval = null;
    this.pongTimeout = null;
    this.init();
  }

  init() {
    this._ws = new WebSocket('wss://pubsub-edge.twitch.tv');

    this._ws.onopen = this.onOpen.bind(this);
    this._ws.onmessage = this.onMessage.bind(this);
    this._ws.onerror = this.onError.bind(this);
    this._ws.onclose = this.onClose.bind(this);
  }

  reconnect() {
    console.warn('Reconnecting to server...');

    clearInterval(this.pingInterval);
    clearTimeout(this.pongTimeout);
    this.init();
  }

  onOpen() {
    this.sendPing();
    this.pingInterval = setInterval(() => this.sendPing(), 5000 * 60);
  }

  onMessage(message) {
    const data = JSON.parse(message.data);

    // console.log(message);
    // console.log(data);

    switch (data.type) {
      case 'PONG':
        this._handleMessagePong();
        break;
      case 'RECONNECT':
        this._handleMessageReconnect();
        break;
      default:
        console.log('yo');
    }
  }

  onError(error) {
    console.error(error);
  }

  onClose(msg) {
    console.info('Connection closed', msg);
  }

  send(message) {
    this._ws.send(message);
  }

  sendJson(data) {
    this.send(JSON.stringify(data));
  }

  sendPing() {
    console.info('Sending PING...');

    this.lastPingTimestamp = +new Date();
    this._reconnectIfPongNotReceived();

    this.sendJson({
      type: 'PING',
    });
  }

  _reconnectIfPongNotReceived() {
    this.pongTimeout = setTimeout(() => {
      console.error('PONG has not been received!');

      this.reconnect();
    }, 10 * 1000);
  }

  _handleMessagePong(data) {
    this.lastPongTimestamp = +new Date();

    console.info('Received PONG in %fms', this.lastPongTimestamp - this.lastPingTimestamp);

    clearTimeout(this.pongTimeout);
  }

  _handleMessageReconnect() {
    const secondsBeforeReboot = 30;

    console.warn(`Server is about to restart in ~${secondsBeforeReboot} seconds...`);

    setTimeout(() => {
      this.reconnect();
    }, secondsBeforeReboot * 1000);
  }
}

export default TwitchWebSocket;