Method doOpen

packages/engine.io-client/lib/transports/webtransport.ts:28–88

()

  }

  protected doOpen() {
    try {
      // @ts-ignore
      this._transport = new WebTransport(
        this.createUri("https"),
        this.opts.transportOptions[this.name],
      );
    } catch (err) {
      return this.emitReserved("error", err);
    }

    this._transport.closed
      .then(() => {
        debug("transport closed gracefully");
        this.onClose();
      })
      .catch((err) => {
        debug("transport closed due to %s", err);
        this.onError("webtransport error", err);
      });

    // note: we could have used async/await, but that would require some additional polyfills
    this._transport.ready.then(() => {
      this._transport.createBidirectionalStream().then((stream) => {
        const decoderStream = createPacketDecoderStream(
          Number.MAX_SAFE_INTEGER,
          this.socket.binaryType,
        );
        const reader = stream.readable.pipeThrough(decoderStream).getReader();

        const encoderStream = createPacketEncoderStream();
        encoderStream.readable.pipeTo(stream.writable);
        this._writer = encoderStream.writable.getWriter();

        const read = () => {
          reader
            .read()
            .then(({ done, value }) => {
              if (done) {
                debug("session is closed");
                return;
              }
              debug("received chunk: %o", value);
              this.onPacket(value);
              read();
            })
            .catch((err) => {
              debug("an error occurred while reading: %s", err);
            });
        };

        read();

        const packet: Packet = { type: "open" };
        if (this.query.sid) {
          packet.data = `{"sid":"${this.query.sid}"}`;
        }
        this._writer.write(packet).then(() => this.onOpen());