Function encodePayload

packages/engine.io-parser/lib/index.ts:13–31

(
  packets: Packet[],
  callback: (encodedPayload: string) => void,
)

const SEPARATOR = String.fromCharCode(30); // see https://en.wikipedia.org/wiki/Delimiter#ASCII_delimited_text

const encodePayload = (
  packets: Packet[],
  callback: (encodedPayload: string) => void,
) => {
  // some packets may be added to the array while encoding, so the initial length must be saved
  const length = packets.length;
  const encodedPackets = new Array(length);
  let count = 0;

  packets.forEach((packet, i) => {
    // force base64 encoding for binary packets
    encodePacket(packet, false, (encodedPacket) => {
      encodedPackets[i] = encodedPacket;
      if (++count === length) {
        callback(encodedPackets.join(SEPARATOR));
      }
    });
  });
};

const decodePayload = (
  encodedPayload: string,