Method send

deps/undici/src/lib/web/websocket/websocket.js:229–321

* @see https://websockets.spec.whatwg.org/#dom-websocket-send * @param {NodeJS.TypedArray|ArrayBuffer|Blob|string} data

(data)

   * @param {NodeJS.TypedArray|ArrayBuffer|Blob|string} data
   */
  send (data) {
    webidl.brandCheck(this, WebSocket)

    const prefix = 'WebSocket.send'
    webidl.argumentLengthCheck(arguments, 1, prefix)

    data = webidl.converters.WebSocketSendData(data, prefix, 'data')

    // 1. If this's ready state is CONNECTING, then throw an
    //    "InvalidStateError" DOMException.
    if (isConnecting(this.#handler.readyState)) {
      throw new DOMException('Sent before connected.', 'InvalidStateError')
    }

    // 2. Run the appropriate set of steps from the following list:
    // https://datatracker.ietf.org/doc/html/rfc6455#section-6.1
    // https://datatracker.ietf.org/doc/html/rfc6455#section-5.2

    if (!isEstablished(this.#handler.readyState) || isClosing(this.#handler.readyState)) {
      return
    }

    // If data is a string
    if (typeof data === 'string') {
      // If the WebSocket connection is established and the WebSocket
      // closing handshake has not yet started, then the user agent
      // must send a WebSocket Message comprised of the data argument
      // using a text frame opcode; if the data cannot be sent, e.g.
      // because it would need to be buffered but the buffer is full,
      // the user agent must flag the WebSocket as full and then close
      // the WebSocket connection. Any invocation of this method with a
      // string argument that does not throw an exception must increase
      // the bufferedAmount attribute by the number of bytes needed to
      // express the argument as UTF-8.

      const buffer = Buffer.from(data)

      this.#bufferedAmount += buffer.byteLength
      this.#sendQueue.add(buffer, () => {
        this.#bufferedAmount -= buffer.byteLength
      }, sendHints.text)
    } else if (isArrayBuffer(data)) {
      // If the WebSocket connection is established, and the WebSocket
      // closing handshake has not yet started, then the user agent must
      // send a WebSocket Message comprised of data using a binary frame
      // opcode; if the data cannot be sent, e.g. because it would need
      // to be buffered but the buffer is full, the user agent must flag
      // the WebSocket as full and then close the WebSocket connection.
      // The data to be sent is the data stored in the buffer described
      // by the ArrayBuffer object. Any invocation of this method with an
      // ArrayBuffer argument that does not throw an exception must
      // increase the bufferedAmount attribute by the length of the
      // ArrayBuffer in bytes.

      this.#bufferedAmount += data.byteLength
      this.#sendQueue.add(data, () => {
        this.#bufferedAmount -= data.byteLength
      }, sendHints.arrayBuffer)