Method _onClose

packages/engine.io-client/lib/socket.ts:909–960

* Called upon transport close. * * @private

(reason: string, description?: CloseDetails | Error)

   * @private
   */
  private _onClose(reason: string, description?: CloseDetails | Error) {
    if (
      "opening" === this.readyState ||
      "open" === this.readyState ||
      "closing" === this.readyState
    ) {
      debug('socket close with reason: "%s"', reason);

      // clear timers
      this.clearTimeoutFn(this._pingTimeoutTimer);

      // stop event from firing again for transport
      this.transport.removeAllListeners("close");

      // ensure transport won't stay open
      this.transport.close();

      // ignore further transport communication
      this.transport.removeAllListeners();

      if (withEventListeners) {
        if (this._beforeunloadEventListener) {
          removeEventListener(
            "beforeunload",
            this._beforeunloadEventListener,
            false,
          );
        }
        if (this._offlineEventListener) {
          const i = OFFLINE_EVENT_LISTENERS.indexOf(this._offlineEventListener);
          if (i !== -1) {
            debug("removing listener for the 'offline' event");
            OFFLINE_EVENT_LISTENERS.splice(i, 1);
          }
        }
      }

      // set ready state
      this.readyState = "closed";

      // clear session id
      this.id = null;

      // emit close event
      this.emitReserved("close", reason, description);

      // clean buffers after, so users can still
      // grab the buffers on `close` event
      this.writeBuffer = [];
      this._prevBufferLen = 0;
    }
  }
}

/**