Method constructor

lib/internal/webstreams/readablestream.js:253–285

* @param {UnderlyingSource} [source] * @param {QueuingStrategy} [strategy]

(source = kEmptyObject, strategy = kEmptyObject)

   * @param {QueuingStrategy} [strategy]
   */
  constructor(source = kEmptyObject, strategy = kEmptyObject) {
    markTransferMode(this, false, true);
    validateObject(source, 'source', kValidateObjectAllowObjects);
    validateObject(strategy, 'strategy', kValidateObjectAllowObjectsAndNull);
    this[kState] = createReadableStreamState();

    // The spec requires handling of the strategy first
    // here. Specifically, if getting the size and
    // highWaterMark from the strategy fail, that has
    // to trigger a throw before getting the details
    // from the source. So be sure to keep these in
    // this order.
    const size = strategy?.size;
    const highWaterMark = strategy?.highWaterMark;
    const type = source.type;

    if (`${type}` === 'bytes') {
      if (size !== undefined)
        throw new ERR_INVALID_ARG_VALUE.RangeError('strategy.size', size);
      setupReadableByteStreamControllerFromSource(
        this,
        source,
        extractHighWaterMark(highWaterMark, 0));
    } else {
      if (type !== undefined)
        throw new ERR_INVALID_ARG_VALUE('source.type', type);
      setupReadableStreamDefaultControllerFromSource(
        this,
        source,
        extractHighWaterMark(highWaterMark, 1),
        extractSizeAlgorithm(size));
    }
  }

  get [kIsDisturbed]() {
    return this[kState].disturbed;