denoland-deno/ext/web/06_streams.js

// Copyright 2018-2022 the Deno authors. All rights reserved. MIT license.

// @ts-check
/// <reference path="../webidl/internal.d.ts" />
/// <reference path="./06_streams_types.d.ts" />
/// <reference path="./lib.deno_web.d.ts" />
/// <reference lib="esnext" />
"use strict";

((window) => {
  const core = window.Deno.core;
  const webidl = window.__bootstrap.webidl;
  const { add, remove, signalAbort, newSignal, AbortSignalPrototype } =
    window.__bootstrap.abortSignal;
  const {
    ArrayBuffer,
    ArrayBufferPrototype,
    ArrayBufferIsView,
    ArrayPrototypeMap,
    ArrayPrototypePush,
    ArrayPrototypeShift,
    BigInt64ArrayPrototype,
    BigUint64ArrayPrototype,
    DataView,
    Int8ArrayPrototype,
    Int16ArrayPrototype,
    Int32ArrayPrototype,
    NumberIsInteger,
    NumberIsNaN,
    MathMin,
    ObjectCreate,
    ObjectDefineProperties,
    ObjectDefineProperty,
    ObjectGetPrototypeOf,
    ObjectPrototypeIsPrototypeOf,
    ObjectSetPrototypeOf,
    Promise,
    PromiseAll,
    PromisePrototypeCatch,
    PromisePrototypeThen,
    PromiseReject,
    PromiseResolve,
    queueMicrotask,
    RangeError,
    ReflectHas,
    SharedArrayBuffer,
    Symbol,
    SymbolAsyncIterator,
    SymbolFor,
    TypeError,
    Uint8Array,
    Uint8ArrayPrototype,
    Uint16ArrayPrototype,
    Uint32ArrayPrototype,
    Uint8ClampedArrayPrototype,
    WeakMap,
    WeakMapPrototypeGet,
    WeakMapPrototypeHas,
    WeakMapPrototypeSet,
  } = globalThis.__bootstrap.primordials;
  const consoleInternal = window.__bootstrap.console;
  const { AssertionError, assert } = window.__bootstrap.infra;

  /** @template T */
  class Deferred {
    /** @type {Promise<T>} */
    #promise;
    /** @type {(reject?: any) => void} */
    #reject;
    /** @type {(value: T | PromiseLike<T>) => void} */
    #resolve;
    /** @type {"pending" | "fulfilled"} */
    #state = "pending";

    constructor() {
      this.#promise = new Promise((resolve, reject) => {
        this.#resolve = resolve;
        this.#reject = reject;
      });
    }

    /** @returns {Promise<T>} */
    get promise() {
      return this.#promise;
    }

    /** @returns {"pending" | "fulfilled"} */
    get state() {
      return this.#state;
    }

    /** @param {any=} reason */
    reject(reason) {
      // already settled promises are a no-op
      if (this.#state !== "pending") {
        return;
      }
      this.#state = "fulfilled";
      this.#reject(reason);
    }

    /** @param {T | PromiseLike<T>} value */
    resolve(value) {
      // already settled promises are a no-op
      if (this.#state !== "pending") {
        return;
      }
      this.#state = "fulfilled";
      this.#resolve(value);
    }
  }

  /**
   * @template T
   * @param {T | PromiseLike<T>} value
   * @returns {Promise<T>}
   */
  function resolvePromiseWith(value) {
    return new Promise((resolve) => resolve(value));
  }

  /** @param {any} e */
  function rethrowAssertionErrorRejection(e) {
    if (e && ObjectPrototypeIsPrototypeOf(AssertionError.prototype, e)) {
      queueMicrotask(() => {
        console.error(`Internal Error: ${e.stack}`);
      });
    }
  }

  /** @param {Promise<any>} promise */
  function setPromiseIsHandledToTrue(promise) {
    PromisePrototypeThen(promise, undefined, rethrowAssertionErrorRejection);
  }

  /**
   * @template T
   * @template TResult1
   * @template TResult2
   * @param {Promise<T>} promise
   * @param {(value: T) => TResult1 | PromiseLike<TResult1>} fulfillmentHandler
   * @param {(reason: any) => TResult2 | PromiseLike<TResult2>=} rejectionHandler
   * @returns {Promise<TResult1 | TResult2>}
   */
  function transformPromiseWith(promise, fulfillmentHandler, rejectionHandler) {
    return PromisePrototypeThen(promise, fulfillmentHandler, rejectionHandler);
  }

  /**
   * @template T
   * @template TResult
   * @param {Promise<T>} promise
   * @param {(value: T) => TResult | PromiseLike<TResult>} onFulfilled
   * @returns {void}
   */
  function uponFulfillment(promise, onFulfilled) {
    uponPromise(promise, onFulfilled);
  }

  /**
   * @template T
   * @template TResult
   * @param {Promise<T>} promise
   * @param {(value: T) => TResult | PromiseLike<TResult>} onRejected
   * @returns {void}
   */
  function uponRejection(promise, onRejected) {
    uponPromise(promise, undefined, onRejected);
  }

  /**
   * @template T
   * @template TResult1
   * @template TResult2
   * @param {Promise<T>} promise
   * @param {(value: T) => TResult1 | PromiseLike<TResult1>} onFulfilled
   * @param {(reason: any) => TResult2 | PromiseLike<TResult2>=} onRejected
   * @returns {void}
   */
  function uponPromise(promise, onFulfilled, onRejected) {
    PromisePrototypeThen(
      PromisePrototypeThen(promise, onFulfilled, onRejected),
      undefined,
      rethrowAssertionErrorRejection,
    );
  }

  const isFakeDetached = Symbol("<<detached>>");

  /**
   * @param {ArrayBufferLike} O
   * @returns {boolean}
   */
  function isDetachedBuffer(O) {
    return ReflectHas(O, isFakeDetached);
  }

  /**
   * @param {ArrayBufferLike} O
   * @returns {boolean}
   */
  function canTransferArrayBuffer(O) {
    assert(typeof O === "object");
    assert(
      ObjectPrototypeIsPrototypeOf(ArrayBufferPrototype, O) ||
        ObjectPrototypeIsPrototypeOf(SharedArrayBuffer.prototype, O),
    );
    if (isDetachedBuffer(O)) {
      return false;
    }
    // TODO(@crowlKats): 4. If SameValue(O.[[ArrayBufferDetachKey]], undefined) is false, return false.
    return true;
  }

  /**
   * @param {ArrayBufferLike} O
   * @returns {ArrayBufferLike}
   */
  function transferArrayBuffer(O) {
    assert(!isDetachedBuffer(O));
    const transferredIshVersion = O.slice(0);
    ObjectDefineProperty(O, "byteLength", {
      get() {
        return 0;
      },
    });
    O[isFakeDetached] = true;
    return transferredIshVersion;
  }

  /**
   * @param {ArrayBufferView} O
   * @returns {Uint8Array}
   */
  function cloneAsUint8Array(O) {
    assert(typeof O === "object");
    assert(ArrayBufferIsView(O));
    assert(!isDetachedBuffer(O.buffer));
    const buffer = O.buffer.slice(O.byteOffset, O.byteOffset + O.byteLength);
    return new Uint8Array(buffer);
  }

  const _abortAlgorithm = Symbol("[[abortAlgorithm]]");
  const _abortSteps = Symbol("[[AbortSteps]]");
  const _autoAllocateChunkSize = Symbol("[[autoAllocateChunkSize]]");
  const _backpressure = Symbol("[[backpressure]]");
  const _backpressureChangePromise = Symbol("[[backpressureChangePromise]]");
  const _byobRequest = Symbol("[[byobRequest]]");
  const _cancelAlgorithm = Symbol("[[cancelAlgorithm]]");
  const _cancelSteps = Symbol("[[CancelSteps]]");
  const _close = Symbol("close sentinel");
  const _closeAlgorithm = Symbol("[[closeAlgorithm]]");
  const _closedPromise = Symbol("[[closedPromise]]");
  const _closeRequest = Symbol("[[closeRequest]]");
  const _closeRequested = Symbol("[[closeRequested]]");
  const _controller = Symbol("[[controller]]");
  const _detached = Symbol("[[Detached]]");
  const _disturbed = Symbol("[[disturbed]]");
  const _errorSteps = Symbol("[[ErrorSteps]]");
  const _flushAlgorithm = Symbol("[[flushAlgorithm]]");
  const _globalObject = Symbol("[[globalObject]]");
  const _highWaterMark = Symbol("[[highWaterMark]]");
  const _inFlightCloseRequest = Symbol("[[inFlightCloseRequest]]");
  const _inFlightWriteRequest = Symbol("[[inFlightWriteRequest]]");
  const _pendingAbortRequest = Symbol("[pendingAbortRequest]");
  const _pendingPullIntos = Symbol("[[pendingPullIntos]]");
  const _preventCancel = Symbol("[[preventCancel]]");
  const _pullAgain = Symbol("[[pullAgain]]");
  const _pullAlgorithm = Symbol("[[pullAlgorithm]]");
  const _pulling = Symbol("[[pulling]]");
  const _pullSteps = Symbol("[[PullSteps]]");
  const _releaseSteps = Symbol("[[ReleaseSteps]]");
  const _queue = Symbol("[[queue]]");
  const _queueTotalSize = Symbol("[[queueTotalSize]]");
  const _readable = Symbol("[[readable]]");
  const _reader = Symbol("[[reader]]");
  const _readRequests = Symbol("[[readRequests]]");
  const _readIntoRequests = Symbol("[[readIntoRequests]]");
  const _readyPromise = Symbol("[[readyPromise]]");
  const _signal = Symbol("[[signal]]");
  const _started = Symbol("[[started]]");
  const _state = Symbol("[[state]]");
  const _storedError = Symbol("[[storedError]]");
  const _strategyHWM = Symbol("[[strategyHWM]]");
  const _strategySizeAlgorithm = Symbol("[[strategySizeAlgorithm]]");
  const _stream = Symbol("[[stream]]");
  const _transformAlgorithm = Symbol("[[transformAlgorithm]]");
  const _view = Symbol("[[view]]");
  const _writable = Symbol("[[writable]]");
  const _writeAlgorithm = Symbol("[[writeAlgorithm]]");
  const _writer = Symbol("[[writer]]");
  const _writeRequests = Symbol("[[writeRequests]]");

  /**
   * @template R
   * @param {ReadableStream<R>} stream
   * @returns {ReadableStreamDefaultReader<R>}
   */
  function acquireReadableStreamDefaultReader(stream) {
    return new ReadableStreamDefaultReader(stream);
  }

  /**
   * @template R
   * @param {ReadableStream<R>} stream
   * @returns {ReadableStreamBYOBReader<R>}
   */
  function acquireReadableStreamBYOBReader(stream) {
    const reader = webidl.createBranded(ReadableStreamBYOBReader);
    setUpReadableStreamBYOBReader(reader, stream);
    return reader;
  }

  /**
   * @template W
   * @param {WritableStream<W>} stream
   * @returns {WritableStreamDefaultWriter<W>}
   */
  function acquireWritableStreamDefaultWriter(stream) {
    return new WritableStreamDefaultWriter(stream);
  }

  /**
   * @template R
   * @param {() => void} startAlgorithm
   * @param {() => Promise<void>} pullAlgorithm
   * @param {(reason: any) => Promise<void>} cancelAlgorithm
   * @param {number=} highWaterMark
   * @param {((chunk: R) => number)=} sizeAlgorithm
   * @returns {ReadableStream<R>}
   */
  function createReadableStream(
    startAlgorithm,
    pullAlgorithm,
    cancelAlgorithm,
    highWaterMark = 1,
    sizeAlgorithm = () => 1,
  ) {
    assert(isNonNegativeNumber(highWaterMark));
    /** @type {ReadableStream} */
    const stream = webidl.createBranded(ReadableStream);
    initializeReadableStream(stream);
    const controller = webidl.createBranded(ReadableStreamDefaultController);
    setUpReadableStreamDefaultController(
      stream,
      controller,
      startAlgorithm,
      pullAlgorithm,
      cancelAlgorithm,
      highWaterMark,
      sizeAlgorithm,
    );
    return stream;
  }

  /**
   * @template W
   * @param {(controller: WritableStreamDefaultController<W>) => Promise<void>} startAlgorithm
   * @param {(chunk: W) => Promise<void>} writeAlgorithm
   * @param {() => Promise<void>} closeAlgorithm
   * @param {(reason: any) => Promise<void>} abortAlgorithm
   * @param {number} highWaterMark
   * @param {(chunk: W) => number} sizeAlgorithm
   * @returns {WritableStream<W>}
   */
  function createWritableStream(
    startAlgorithm,
    writeAlgorithm,
    closeAlgorithm,
    abortAlgorithm,
    highWaterMark,
    sizeAlgorithm,
  ) {
    assert(isNonNegativeNumber(highWaterMark));
    const stream = webidl.createBranded(WritableStream);
    initializeWritableStream(stream);
    const controller = webidl.createBranded(WritableStreamDefaultController);
    setUpWritableStreamDefaultController(
      stream,
      controller,
      startAlgorithm,
      writeAlgorithm,
      closeAlgorithm,
      abortAlgorithm,
      highWaterMark,
      sizeAlgorithm,
    );
    return stream;
  }

  /**
   * @template T
   * @param {{ [_queue]: Array<ValueWithSize<T>>, [_queueTotalSize]: number }} container
   * @returns {T}
   */
  function dequeueValue(container) {
    assert(
      ReflectHas(container, _queue) &&
        ReflectHas(container, _queueTotalSize),
    );
    assert(container[_queue].length);
    const valueWithSize = ArrayPrototypeShift(container[_queue]);
    container[_queueTotalSize] -= valueWithSize.size;
    if (container[_queueTotalSize] < 0) {
      container[_queueTotalSize] = 0;
    }
    return valueWithSize.value;
  }

  /**
   * @template T
   * @param {{ [_queue]: Array<ValueWithSize<T | _close>>, [_queueTotalSize]: number }} container
   * @param {T} value
   * @param {number} size
   * @returns {void}
   */
  function enqueueValueWithSize(container, value, size) {
    assert(
      ReflectHas(container, _queue) &&
        ReflectHas(container, _queueTotalSize),
    );
    if (isNonNegativeNumber(size) === false) {
      throw RangeError("chunk size isn't a positive number");
    }
    if (size === Infinity) {
      throw RangeError("chunk size is invalid");
    }
    ArrayPrototypePush(container[_queue], { value, size });
    container[_queueTotalSize] += size;
  }

  /**
   * @param {QueuingStrategy} strategy
   * @param {number} defaultHWM
   */
  function extractHighWaterMark(strategy, defaultHWM) {
    if (strategy.highWaterMark === undefined) {
      return defaultHWM;
    }
    const highWaterMark = strategy.highWaterMark;
    if (NumberIsNaN(highWaterMark) || highWaterMark < 0) {
      throw RangeError(
        `Expected highWaterMark to be a positive number or Infinity, got "${highWaterMark}".`,
      );
    }
    return highWaterMark;
  }

  /**
   * @template T
   * @param {QueuingStrategy<T>} strategy
   * @return {(chunk: T) => number}
   */
  function extractSizeAlgorithm(strategy) {
    if (strategy.size === undefined) {
      return () => 1;
    }
    return (chunk) =>
      webidl.invokeCallbackFunction(
        strategy.size,
        [chunk],
        undefined,
        webidl.converters["unrestricted double"],
        { prefix: "Failed to call `sizeAlgorithm`" },
      );
  }

  /**
   * @param {() => void} startAlgorithm
   * @param {() => Promise<void>} pullAlgorithm
   * @param {(reason: any) => Promise<void>} cancelAlgorithm
   * @returns {ReadableStream}
   */
  function createReadableByteStream(
    startAlgorithm,
    pullAlgorithm,
    cancelAlgorithm,
  ) {
    const stream = webidl.createBranded(ReadableStream);
    initializeReadableStream(stream);
    const controller = webidl.createBranded(ReadableByteStreamController);
    setUpReadableByteStreamController(
      stream,
      controller,
      startAlgorithm,
      pullAlgorithm,
      cancelAlgorithm,
      0,
      undefined,
    );
    return stream;
  }

  /**
   * @param {ReadableStream} stream
   * @returns {void}
   */
  function initializeReadableStream(stream) {
    stream[_state] = "readable";
    stream[_reader] = stream[_storedError] = undefined;
    stream[_disturbed] = false;
  }

  /**
   * @template I
   * @template O
   * @param {TransformStream<I, O>} stream
   * @param {Deferred<void>} startPromise
   * @param {number} writableHighWaterMark
   * @param {(chunk: I) => number} writableSizeAlgorithm
   * @param {number} readableHighWaterMark
   * @param {(chunk: O) => number} readableSizeAlgorithm
   */
  function initializeTransformStream(
    stream,
    startPromise,
    writableHighWaterMark,
    writableSizeAlgorithm,
    readableHighWaterMark,
    readableSizeAlgorithm,
  ) {
    function startAlgorithm() {
      return startPromise.promise;
    }

    function writeAlgorithm(chunk) {
      return transformStreamDefaultSinkWriteAlgorithm(stream, chunk);
    }

    function abortAlgorithm(reason) {
      return transformStreamDefaultSinkAbortAlgorithm(stream, reason);
    }

    function closeAlgorithm() {
      return transformStreamDefaultSinkCloseAlgorithm(stream);
    }

    stream[_writable] = createWritableStream(
      startAlgorithm,
      writeAlgorithm,
      closeAlgorithm,
      abortAlgorithm,
      writableHighWaterMark,
      writableSizeAlgorithm,
    );

    function pullAlgorithm() {
      return transformStreamDefaultSourcePullAlgorithm(stream);
    }

    function cancelAlgorithm(reason) {
      transformStreamErrorWritableAndUnblockWrite(stream, reason);
      return resolvePromiseWith(undefined);
    }

    stream[_readable] = createReadableStream(
      startAlgorithm,
      pullAlgorithm,
      cancelAlgorithm,
      readableHighWaterMark,
      readableSizeAlgorithm,
    );

    stream[_backpressure] = stream[_backpressureChangePromise] = undefined;
    transformStreamSetBackpressure(stream, true);
    stream[_controller] = undefined;
  }

  /** @param {WritableStream} stream */
  function initializeWritableStream(stream) {
    stream[_state] = "writable";
    stream[_storedError] =
      stream[_writer] =
      stream[_controller] =
      stream[_inFlightWriteRequest] =
      stream[_closeRequest] =
      stream[_inFlightCloseRequest] =
      stream[_pendingAbortRequest] =
        undefined;
    stream[_writeRequests] = [];
    stream[_backpressure] = false;
  }

  /**
   * @param {unknown} v
   * @returns {v is number}
   */
  function isNonNegativeNumber(v) {
    if (typeof v !== "number") {
      return false;
    }
    if (NumberIsNaN(v)) {
      return false;
    }
    if (v < 0) {
      return false;
    }
    return true;
  }

  /**
   * @param {unknown} value
   * @returns {value is ReadableStream}
   */
  function isReadableStream(value) {
    return !(typeof value !== "object" || value === null ||
      !ReflectHas(value, _controller));
  }

  /**
   * @param {ReadableStream} stream
   * @returns {boolean}
   */
  function isReadableStreamLocked(stream) {
    if (stream[_reader] === undefined) {
      return false;
    }
    return true;
  }

  /**
   * @param {unknown} value
   * @returns {value is ReadableStreamDefaultReader}
   */
  function isReadableStreamDefaultReader(value) {
    return !(typeof value !== "object" || value === null ||
      !ReflectHas(value, _readRequests));
  }

  /**
   * @param {unknown} value
   * @returns {value is ReadableStreamBYOBReader}
   */
  function isReadableStreamBYOBReader(value) {
    return !(typeof value !== "object" || value === null ||
      !ReflectHas(value, _readIntoRequests));
  }

  /**
   * @param {ReadableStream} stream
   * @returns {boolean}
   */
  function isReadableStreamDisturbed(stream) {
    assert(isReadableStream(stream));
    return stream[_disturbed];
  }

  const DEFAULT_CHUNK_SIZE = 64 * 1024; // 64 KiB

  function readableStreamForRid(rid) {
    const stream = new ReadableStream({
      type: "bytes",
      async pull(controller) {
        const v = controller.byobRequest.view;
        try {
          const bytesRead = await core.read(rid, v);
          if (bytesRead === 0) {
            core.tryClose(rid);
            controller.close();
            controller.byobRequest.respond(0);
          } else {
            controller.byobRequest.respond(bytesRead);
          }
        } catch (e) {
          controller.error(e);
          core.tryClose(rid);
        }
      },
      cancel() {
        core.tryClose(rid);
      },
      autoAllocateChunkSize: DEFAULT_CHUNK_SIZE,
    });

    stream[_maybeRid] = rid;
    return stream;
  }

  function getReadableStreamRid(stream) {
    return stream[_maybeRid];
  }

  /**
   * @param {unknown} value
   * @returns {value is WritableStream}
   */
  function isWritableStream(value) {
    return !(typeof value !== "object" || value === null ||
      !ReflectHas(value, _controller));
  }

  /**
   * @param {WritableStream} stream
   * @returns {boolean}
   */
  function isWritableStreamLocked(stream) {
    if (stream[_writer] === undefined) {
      return false;
    }
    return true;
  }

  /**
   * @template T
   * @param {{ [_queue]: Array<ValueWithSize<T | _close>>, [_queueTotalSize]: number }} container
   * @returns {T | _close}
   */
  function peekQueueValue(container) {
    assert(
      ReflectHas(container, _queue) &&
        ReflectHas(container, _queueTotalSize),
    );
    assert(container[_queue].length);
    const valueWithSize = container[_queue][0];
    return valueWithSize.value;
  }

  /**
   * @param {ReadableByteStreamController} controller
   * @returns {void}
   */
  function readableByteStreamControllerCallPullIfNeeded(controller) {
    const shouldPull = readableByteStreamControllerShouldCallPull(controller);
    if (!shouldPull) {
      return;
    }
    if (controller[_pulling]) {
      controller[_pullAgain] = true;
      return;
    }
    assert(controller[_pullAgain] === false);
    controller[_pulling] = true;
    /** @type {Promise<void>} */
    const pullPromise = controller[_pullAlgorithm](controller);
    setPromiseIsHandledToTrue(
      PromisePrototypeThen(
        pullPromise,
        () => {
          controller[_pulling] = false;
          if (controller[_pullAgain]) {
            controller[_pullAgain] = false;
            readableByteStreamControllerCallPullIfNeeded(controller);
          }
        },
        (e) => {
          readableByteStreamControllerError(controller, e);
        },
      ),
    );
  }

  /**
   * @param {ReadableByteStreamController} controller
   * @returns {void}
   */
  function readableByteStreamControllerClearAlgorithms(controller) {
    controller[_pullAlgorithm] = undefined;
    controller[_cancelAlgorithm] = undefined;
  }

  /**
   * @param {ReadableByteStreamController} controller
   * @param {any} e
   */
  function readableByteStreamControllerError(controller, e) {
    /** @type {ReadableStream<ArrayBuffer>} */
    const stream = controller[_stream];
    if (stream[_state] !== "readable") {
      return;
    }
    readableByteStreamControllerClearPendingPullIntos(controller);
    resetQueue(controller);
    readableByteStreamControllerClearAlgorithms(controller);
    readableStreamError(stream, e);
  }

  /**
   * @param {ReadableByteStreamController} controller
   * @returns {void}
   */
  function readableByteStreamControllerClearPendingPullIntos(controller) {
    readableByteStreamControllerInvalidateBYOBRequest(controller);
    controller[_pendingPullIntos] = [];
  }

  /**
   * @param {ReadableByteStreamController} controller
   * @returns {void}
   */
  function readableByteStreamControllerClose(controller) {
    /** @type {ReadableStream<ArrayBuffer>} */
    const stream = controller[_stream];
    if (controller[_closeRequested] || stream[_state] !== "readable") {
      return;
    }
    if (controller[_queueTotalSize] > 0) {
      controller[_closeRequested] = true;
      return;
    }
    if (controller[_pendingPullIntos].length !== 0) {
      const firstPendingPullInto = controller[_pendingPullIntos][0];
      if (firstPendingPullInto.bytesFilled > 0) {
        const e = new TypeError(
          "Insufficient bytes to fill elements in the given buffer",
        );
        readableByteStreamControllerError(controller, e);
        throw e;
      }
    }
    readableByteStreamControllerClearAlgorithms(controller);
    readableStreamClose(stream);
  }

  /**
   * @param {ReadableByteStreamController} controller
   * @param {ArrayBufferView} chunk
   */
  function readableByteStreamControllerEnqueue(controller, chunk) {
    /** @type {ReadableStream<ArrayBuffer>} */
    const stream = controller[_stream];
    if (
      controller[_closeRequested] ||
      controller[_stream][_state] !== "readable"
    ) {
      return;
    }

    const { buffer, byteOffset, byteLength } = chunk;
    if (isDetachedBuffer(buffer)) {
      throw new TypeError(
        "chunk's buffer is detached and so cannot be enqueued",
      );
    }
    const transferredBuffer = transferArrayBuffer(buffer);
    if (controller[_pendingPullIntos].length !== 0) {
      const firstPendingPullInto = controller[_pendingPullIntos][0];
      if (isDetachedBuffer(firstPendingPullInto.buffer)) {
        throw new TypeError(
          "The BYOB request's buffer has been detached and so cannot be filled with an enqueued chunk",
        );
      }
      readableByteStreamControllerInvalidateBYOBRequest(controller);
      firstPendingPullInto.buffer = transferArrayBuffer(
        firstPendingPullInto.buffer,
      );
      if (firstPendingPullInto.readerType === "none") {
        readableByteStreamControllerEnqueueDetachedPullIntoToQueue(
          controller,
          firstPendingPullInto,
        );
      }
    }
    if (readableStreamHasDefaultReader(stream)) {
      readableByteStreamControllerProcessReadRequestsUsingQueue(controller);
      if (readableStreamGetNumReadRequests(stream) === 0) {
        assert(controller[_pendingPullIntos].length === 0);
        readableByteStreamControllerEnqueueChunkToQueue(
          controller,
          transferredBuffer,
          byteOffset,
          byteLength,
        );
      } else {
        assert(controller[_queue].length === 0);
        if (controller[_pendingPullIntos].length !== 0) {
          assert(controller[_pendingPullIntos][0].readerType === "default");
          readableByteStreamControllerShiftPendingPullInto(controller);
        }
        const transferredView = new Uint8Array(
          transferredBuffer,
          byteOffset,
          byteLength,
        );
        readableStreamFulfillReadRequest(stream, transferredView, false);
      }
    } else if (readableStreamHasBYOBReader(stream)) {
      readableByteStreamControllerEnqueueChunkToQueue(
        controller,
        transferredBuffer,
        byteOffset,
        byteLength,
      );
      readableByteStreamControllerProcessPullIntoDescriptorsUsingQueue(
        controller,
      );
    } else {
      assert(isReadableStreamLocked(stream) === false);
      readableByteStreamControllerEnqueueChunkToQueue(
        controller,
        transferredBuffer,
        byteOffset,
        byteLength,
      );
    }
    readableByteStreamControllerCallPullIfNeeded(controller);
  }

  /**
   * @param {ReadableByteStreamController} controller
   * @param {ArrayBufferLike} buffer
   * @param {number} byteOffset
   * @param {number} byteLength
   * @returns {void}
   */
  function readableByteStreamControllerEnqueueChunkToQueue(
    controller,
    buffer,
    byteOffset,
    byteLength,
  ) {
    ArrayPrototypePush(controller[_queue], { buffer, byteOffset, byteLength });
    controller[_queueTotalSize] += byteLength;
  }

  /**
   * @param {ReadableByteStreamController} controller
   * @param {ArrayBufferLike} buffer
   * @param {number} byteOffset
   * @param {number} byteLength
   * @returns {void}
   */
  function readableByteStreamControllerEnqueueClonedChunkToQueue(
    controller,
    buffer,
    byteOffset,
    byteLength,
  ) {
    let cloneResult;
    try {
      cloneResult = buffer.slice(byteOffset, byteOffset + byteLength);
    } catch (e) {
      readableByteStreamControllerError(controller, e);
    }
    readableByteStreamControllerEnqueueChunkToQueue(
      controller,
      cloneResult,
      0,
      byteLength,
    );
  }

  /**
   * @param {ReadableByteStreamController} controller
   * @param {PullIntoDescriptor} pullIntoDescriptor
   * @returns {void}
   */
  function readableByteStreamControllerEnqueueDetachedPullIntoToQueue(
    controller,
    pullIntoDescriptor,
  ) {
    assert(pullIntoDescriptor.readerType === "none");
    if (pullIntoDescriptor.bytesFilled > 0) {
      readableByteStreamControllerEnqueueClonedChunkToQueue(
        controller,
        pullIntoDescriptor.buffer,
        pullIntoDescriptor.byteOffset,
        pullIntoDescriptor.bytesFilled,
      );
    }
    readableByteStreamControllerShiftPendingPullInto(controller);
  }

  /**
   * @param {ReadableByteStreamController} controller
   * @returns {ReadableStreamBYOBRequest | null}
   */
  function readableByteStreamControllerGetBYOBRequest(controller) {
    if (
      controller[_byobRequest] === null &&
      controller[_pendingPullIntos].length !== 0
    ) {
      const firstDescriptor = controller[_pendingPullIntos][0];
      const view = new Uint8Array(
        firstDescriptor.buffer,
        firstDescriptor.byteOffset + firstDescriptor.bytesFilled,
        firstDescriptor.byteLength - firstDescriptor.bytesFilled,
      );
      const byobRequest = webidl.createBranded(ReadableStreamBYOBRequest);
      byobRequest[_controller] = controller;
      byobRequest[_view] = view;
      controller[_byobRequest] = byobRequest;
    }
    return controller[_byobRequest];
  }

  /**
   * @param {ReadableByteStreamController} controller
   * @returns {number | null}
   */
  function readableByteStreamControllerGetDesiredSize(controller) {
    const state = controller[_stream][_state];
    if (state === "errored") {
      return null;
    }
    if (state === "closed") {
      return 0;
    }
    return controller[_strategyHWM] - controller[_queueTotalSize];
  }

  /**
   * @param {{ [_queue]: any[], [_queueTotalSize]: number }} container
   * @returns {void}
   */
  function resetQueue(container) {
    container[_queue] = [];
    container[_queueTotalSize] = 0;
  }

  /**
   * @param {ReadableByteStreamController} controller
   * @returns {void}
   */
  function readableByteStreamControllerHandleQueueDrain(controller) {
    assert(controller[_stream][_state] === "readable");
    if (
      controller[_queueTotalSize] === 0 && controller[_closeRequested]
    ) {
      readableByteStreamControllerClearAlgorithms(controller);
      readableStreamClose(controller[_stream]);
    } else {
      readableByteStreamControllerCallPullIfNeeded(controller);
    }
  }

  /**
   * @param {ReadableByteStreamController} controller
   * @returns {boolean}
   */
  function readableByteStreamControllerShouldCallPull(controller) {
    /** @type {ReadableStream<ArrayBuffer>} */
    const stream = controller[_stream];
    if (
      stream[_state] !== "readable" ||
      controller[_closeRequested] ||
      !controller[_started]
    ) {
      return false;
    }
    if (
      readableStreamHasDefaultReader(stream) &&
      readableStreamGetNumReadRequests(stream) > 0
    ) {
      return true;
    }
    if (
      readableStreamHasBYOBReader(stream) &&
      readableStreamGetNumReadIntoRequests(stream) > 0
    ) {
      return true;
    }
    const desiredSize = readableByteStreamControllerGetDesiredSize(controller);
    assert(desiredSize !== null);
    return desiredSize > 0;
  }

  /**
   * @template R
   * @param {ReadableStream<R>} stream
   * @param {ReadRequest<R>} readRequest
   * @returns {void}
   */
  function readableStreamAddReadRequest(stream, readRequest) {
    assert(isReadableStreamDefaultReader(stream[_reader]));
    assert(stream[_state] === "readable");
    ArrayPrototypePush(stream[_reader][_readRequests], readRequest);
  }

  /**
   * @param {ReadableStream} stream
   * @param {ReadIntoRequest} readRequest
   * @returns {void}
   */
  function readableStreamAddReadIntoRequest(stream, readRequest) {
    assert(isReadableStreamBYOBReader(stream[_reader]));
    assert(stream[_state] === "readable" || stream[_state] === "closed");
    ArrayPrototypePush(stream[_reader][_readIntoRequests], readRequest);
  }

  /**
   * @template R
   * @param {ReadableStream<R>} stream
   * @param {any=} reason
   * @returns {Promise<void>}
   */
  function readableStreamCancel(stream, reason) {
    stream[_disturbed] = true;
    if (stream[_state] === "closed") {
      return resolvePromiseWith(undefined);
    }
    if (stream[_state] === "errored") {
      return PromiseReject(stream[_storedError]);
    }
    readableStreamClose(stream);
    const reader = stream[_reader];
    if (reader !== undefined && isReadableStreamBYOBReader(reader)) {
      const readIntoRequests = reader[_readIntoRequests];
      reader[_readIntoRequests] = [];
      for (const readIntoRequest of readIntoRequests) {
        readIntoRequest.closeSteps(undefined);
      }
    }
    /** @type {Promise<void>} */
    const sourceCancelPromise = stream[_controller][_cancelSteps](reason);
    return PromisePrototypeThen(sourceCancelPromise, () => undefined);
  }

  /**
   * @template R
   * @param {ReadableStream<R>} stream
   * @returns {void}
   */
  function readableStreamClose(stream) {
    assert(stream[_state] === "readable");
    stream[_state] = "closed";
    /** @type {ReadableStreamDefaultReader<R> | undefined} */
    const reader = stream[_reader];
    if (!reader) {
      return;
    }
    if (isReadableStreamDefaultReader(reader)) {
      /** @type {Array<ReadRequest<R>>} */
      const readRequests = reader[_readRequests];
      reader[_readRequests] = [];
      for (const readRequest of readRequests) {
        readRequest.closeSteps();
      }
    }
    // This promise can be double resolved.
    // See: https://github.com/whatwg/streams/issues/1100
    reader[_closedPromise].resolve(undefined);
  }

  /** @param {ReadableStreamDefaultController<any>} controller */
  function readableStreamDefaultControllerCallPullIfNeeded(controller) {
    const shouldPull = readableStreamDefaultcontrollerShouldCallPull(
      controller,
    );
    if (shouldPull === false) {
      return;
    }
    if (controller[_pulling] === true) {
      controller[_pullAgain] = true;
      return;
    }
    assert(controller[_pullAgain] === false);
    controller[_pulling] = true;
    const pullPromise = controller[_pullAlgorithm](controller);
    uponFulfillment(pullPromise, () => {
      controller[_pulling] = false;
      if (controller[_pullAgain] === true) {
        controller[_pullAgain] = false;
        readableStreamDefaultControllerCallPullIfNeeded(controller);
      }
    });
    uponRejection(pullPromise, (e) => {
      readableStreamDefaultControllerError(controller, e);
    });
  }

  /**
   * @param {ReadableStreamDefaultController<any>} controller
   * @returns {boolean}
   */
  function readableStreamDefaultControllerCanCloseOrEnqueue(controller) {
    const state = controller[_stream][_state];
    if (controller[_closeRequested] === false && state === "readable") {
      return true;
    } else {
      return false;
    }
  }

  /** @param {ReadableStreamDefaultController<any>} controller */
  function readableStreamDefaultControllerClearAlgorithms(controller) {
    controller[_pullAlgorithm] = undefined;
    controller[_cancelAlgorithm] = undefined;
    controller[_strategySizeAlgorithm] = undefined;
  }

  /** @param {ReadableStreamDefaultController<any>} controller */
  function readableStreamDefaultControllerClose(controller) {
    if (
      readableStreamDefaultControllerCanCloseOrEnqueue(controller) === false
    ) {
      return;
    }
    const stream = controller[_stream];
    controller[_closeRequested] = true;
    if (controller[_queue].length === 0) {
      readableStreamDefaultControllerClearAlgorithms(controller);
      readableStreamClose(stream);
    }
  }

  /**
   * @template R
   * @param {ReadableStreamDefaultController<R>} controller
   * @param {R} chunk
   * @returns {void}
   */
  function readableStreamDefaultControllerEnqueue(controller, chunk) {
    if (
      readableStreamDefaultControllerCanCloseOrEnqueue(controller) === false
    ) {
      return;
    }
    const stream = controller[_stream];
    if (
      isReadableStreamLocked(stream) === true &&
      readableStreamGetNumReadRequests(stream) > 0
    ) {
      readableStreamFulfillReadRequest(stream, chunk, false);
    } else {
      let chunkSize;
      try {
        chunkSize = controller[_strategySizeAlgorithm](chunk);
      } catch (e) {
        readableStreamDefaultControllerError(controller, e);
        throw e;
      }

      try {
        enqueueValueWithSize(controller, chunk, chunkSize);
      } catch (e) {
        readableStreamDefaultControllerError(controller, e);
        throw e;
      }
    }
    readableStreamDefaultControllerCallPullIfNeeded(controller);
  }

  /**
   * @param {ReadableStreamDefaultController<any>} controller
   * @param {any} e
   */
  function readableStreamDefaultControllerError(controller, e) {
    const stream = controller[_stream];
    if (stream[_state] !== "readable") {
      return;
    }
    resetQueue(controller);
    readableStreamDefaultControllerClearAlgorithms(controller);
    readableStreamError(stream, e);
  }

  /**
   * @param {ReadableStreamDefaultController<any>} controller
   * @returns {number | null}
   */
  function readableStreamDefaultControllerGetDesiredSize(controller) {
    const state = controller[_stream][_state];
    if (state === "errored") {
      return null;
    }
    if (state === "closed") {
      return 0;
    }
    return controller[_strategyHWM] - controller[_queueTotalSize];
  }

  /** @param {ReadableStreamDefaultController} controller */
  function readableStreamDefaultcontrollerHasBackpressure(controller) {
    if (readableStreamDefaultcontrollerShouldCallPull(controller) === true) {
      return false;
    } else {
      return true;
    }
  }

  /**
   * @param {ReadableStreamDefaultController<any>} controller
   * @returns {boolean}
   */
  function readableStreamDefaultcontrollerShouldCallPull(controller) {
    const stream = controller[_stream];
    if (
      readableStreamDefaultControllerCanCloseOrEnqueue(controller) === false
    ) {
      return false;
    }
    if (controller[_started] === false) {
      return false;
    }
    if (
      isReadableStreamLocked(stream) &&
      readableStreamGetNumReadRequests(stream) > 0
    ) {
      return true;
    }
    const desiredSize = readableStreamDefaultControllerGetDesiredSize(
      controller,
    );
    assert(desiredSize !== null);
    if (desiredSize > 0) {
      return true;
    }
    return false;
  }

  /**
   * @param {ReadableStreamBYOBReader} reader
   * @param {ArrayBufferView} view
   * @param {ReadIntoRequest} readIntoRequest
   * @returns {void}
   */
  function readableStreamBYOBReaderRead(reader, view, readIntoRequest) {
    const stream = reader[_stream];
    assert(stream);
    stream[_disturbed] = true;
    if (stream[_state] === "errored") {
      readIntoRequest.errorSteps(stream[_storedError]);
    } else {
      readableByteStreamControllerPullInto(
        stream[_controller],
        view,
        readIntoRequest,
      );
    }
  }

  /**
   * @param {ReadableStreamBYOBReader} reader
   */
  function readableStreamBYOBReaderRelease(reader) {
    readableStreamReaderGenericRelease(reader);
    const e = new TypeError("The reader was released.");
    readableStreamBYOBReaderErrorReadIntoRequests(reader, e);
  }

  /**
   * @param {ReadableStreamBYOBReader} reader
   * @param {any} e
   */
  function readableStreamDefaultReaderErrorReadRequests(reader, e) {
    const readRequests = reader[_readRequests];
    reader[_readRequests] = [];
    for (const readRequest of readRequests) {
      readRequest.errorSteps(e);
    }
  }

  /**
   * @param {ReadableByteStreamController} controller
   */
  function readableByteStreamControllerProcessPullIntoDescriptorsUsingQueue(
    controller,
  ) {
    assert(!controller[_closeRequested]);
    while (controller[_pendingPullIntos].length !== 0) {
      if (controller[_queueTotalSize] === 0) {
        return;
      }
      const pullIntoDescriptor = controller[_pendingPullIntos][0];
      if (
        readableByteStreamControllerFillPullIntoDescriptorFromQueue(
          controller,
          pullIntoDescriptor,
        )
      ) {
        readableByteStreamControllerShiftPendingPullInto(controller);
        readableByteStreamControllerCommitPullIntoDescriptor(
          controller[_stream],
          pullIntoDescriptor,
        );
      }
    }
  }
  /**
   * @param {ReadableByteStreamController} controller
   */
  function readableByteStreamControllerProcessReadRequestsUsingQueue(
    controller,
  ) {
    const reader = controller[_stream][_reader];
    assert(isReadableStreamDefaultReader(reader));
    while (reader[_readRequests].length !== 0) {
      if (controller[_queueTotalSize] === 0) {
        return;
      }
      const readRequest = ArrayPrototypeShift(reader[_readRequests]);
      readableByteStreamControllerFillReadRequestFromQueue(
        controller,
        readRequest,
      );
    }
  }

  /**
   * @param {ReadableByteStreamController} controller
   * @param {ArrayBufferView} view
   * @param {ReadIntoRequest} readIntoRequest
   * @returns {void}
   */
  function readableByteStreamControllerPullInto(
    controller,
    view,
    readIntoRequest,
  ) {
    const stream = controller[_stream];
    let elementSize = 1;
    let ctor = DataView;

    if (
      ObjectPrototypeIsPrototypeOf(Int8ArrayPrototype, view) ||
      ObjectPrototypeIsPrototypeOf(Uint8ArrayPrototype, view) ||
      ObjectPrototypeIsPrototypeOf(Uint8ClampedArrayPrototype, view) ||
      ObjectPrototypeIsPrototypeOf(Int16ArrayPrototype, view) ||
      ObjectPrototypeIsPrototypeOf(Uint16ArrayPrototype, view) ||
      ObjectPrototypeIsPrototypeOf(Int32ArrayPrototype, view) ||
      ObjectPrototypeIsPrototypeOf(Uint32ArrayPrototype, view) ||
      ObjectPrototypeIsPrototypeOf(BigInt64ArrayPrototype, view) ||
      ObjectPrototypeIsPrototypeOf(BigUint64ArrayPrototype, view)
    ) {
      elementSize = view.constructor.BYTES_PER_ELEMENT;
      ctor = view.constructor;
    }
    const byteOffset = view.byteOffset;
    const byteLength = view.byteLength;

    /** @type {ArrayBufferLike} */
    let buffer;

    try {
      buffer = transferArrayBuffer(view.buffer);
    } catch (e) {
      readIntoRequest.errorSteps(e);
      return;
    }

    /** @type {PullIntoDescriptor} */
    const pullIntoDescriptor = {
      buffer,
      bufferByteLength: buffer.byteLength,
      byteOffset,
      byteLength,
      bytesFilled: 0,
      elementSize,
      viewConstructor: ctor,
      readerType: "byob",
    };

    if (controller[_pendingPullIntos].length !== 0) {
      ArrayPrototypePush(controller[_pendingPullIntos], pullIntoDescriptor);
      readableStreamAddReadIntoRequest(stream, readIntoRequest);
      return;
    }
    if (stream[_state] === "closed") {
      const emptyView = new ctor(
        pullIntoDescriptor.buffer,
        pullIntoDescriptor.byteOffset,
        0,
      );
      readIntoRequest.closeSteps(emptyView);
      return;
    }
    if (controller[_queueTotalSize] > 0) {
      if (
        readableByteStreamControllerFillPullIntoDescriptorFromQueue(
          controller,
          pullIntoDescriptor,
        )
      ) {
        const filledView =
          readableByteStreamControllerConvertPullIntoDescriptor(
            pullIntoDescriptor,
          );
        readableByteStreamControllerHandleQueueDrain(controller);
        readIntoRequest.chunkSteps(filledView);
        return;
      }
      if (controller[_closeRequested]) {
        const e = new TypeError(
          "Insufficient bytes to fill elements in the given buffer",
        );
        readableByteStreamControllerError(controller, e);
        readIntoRequest.errorSteps(e);
        return;
      }
    }
    controller[_pendingPullIntos].push(pullIntoDescriptor);
    readableStreamAddReadIntoRequest(stream, readIntoRequest);
    readableByteStreamControllerCallPullIfNeeded(controller);
  }

  /**
   * @param {ReadableByteStreamController} controller
   * @param {number} bytesWritten
   * @returns {void}
   */
  function readableByteStreamControllerRespond(controller, bytesWritten) {
    assert(controller[_pendingPullIntos].length !== 0);
    const firstDescriptor = controller[_pendingPullIntos][0];
    const state = controller[_stream][_state];
    if (state === "closed") {
      if (bytesWritten !== 0) {
        throw new TypeError(
          "bytesWritten must be 0 when calling respond() on a closed stream",
        );
      }
    } else {
      assert(state === "readable");
      if (bytesWritten === 0) {
        throw new TypeError(
          "bytesWritten must be greater than 0 when calling respond() on a readable stream",
        );
      }
      if (
        (firstDescriptor.bytesFilled + bytesWritten) >
          firstDescriptor.byteLength
      ) {
        throw new RangeError("bytesWritten out of range");
      }
    }
    firstDescriptor.buffer = transferArrayBuffer(firstDescriptor.buffer);
    readableByteStreamControllerRespondInternal(controller, bytesWritten);
  }

  /**
   * @param {ReadableByteStreamController} controller
   * @param {number} bytesWritten
   * @param {PullIntoDescriptor} pullIntoDescriptor
   * @returns {void}
   */
  function readableByteStreamControllerRespondInReadableState(
    controller,
    bytesWritten,
    pullIntoDescriptor,
  ) {
    assert(
      (pullIntoDescriptor.bytesFilled + bytesWritten) <=
        pullIntoDescriptor.byteLength,
    );
    readableByteStreamControllerFillHeadPullIntoDescriptor(
      controller,
      bytesWritten,
      pullIntoDescriptor,
    );
    if (pullIntoDescriptor.readerType === "none") {
      readableByteStreamControllerEnqueueDetachedPullIntoToQueue(
        controller,
        pullIntoDescriptor,
      );
      readableByteStreamControllerProcessPullIntoDescriptorsUsingQueue(
        controller,
      );
      return;
    }
    if (pullIntoDescriptor.bytesFilled < pullIntoDescriptor.elementSize) {
      return;
    }
    readableByteStreamControllerShiftPendingPullInto(controller);
    const remainderSize = pullIntoDescriptor.bytesFilled %
      pullIntoDescriptor.elementSize;
    if (remainderSize > 0) {
      const end = pullIntoDescriptor.byteOffset +
        pullIntoDescriptor.bytesFilled;
      readableByteStreamControllerEnqueueClonedChunkToQueue(
        controller,
        pullIntoDescriptor.buffer,
        end - remainderSize,
        remainderSize,
      );
    }
    pullIntoDescriptor.bytesFilled -= remainderSize;
    readableByteStreamControllerCommitPullIntoDescriptor(
      controller[_stream],
      pullIntoDescriptor,
    );
    readableByteStreamControllerProcessPullIntoDescriptorsUsingQueue(
      controller,
    );
  }

  /**
   * @param {ReadableByteStreamController} controller
   * @param {number} bytesWritten
   * @returns {void}
   */
  function readableByteStreamControllerRespondInternal(
    controller,
    bytesWritten,
  ) {
    const firstDescriptor = controller[_pendingPullIntos][0];
    assert(canTransferArrayBuffer(firstDescriptor.buffer));
    readableByteStreamControllerInvalidateBYOBRequest(controller);
    const state = controller[_stream][_state];
    if (state === "closed") {
      assert(bytesWritten === 0);
      readableByteStreamControllerRespondInClosedState(
        controller,
        firstDescriptor,
      );
    } else {
      assert(state === "readable");
      assert(bytesWritten > 0);
      readableByteStreamControllerRespondInReadableState(
        controller,
        bytesWritten,
        firstDescriptor,
      );
    }
    readableByteStreamControllerCallPullIfNeeded(controller);
  }

  /**
   * @param {ReadableByteStreamController} controller
   */
  function readableByteStreamControllerInvalidateBYOBRequest(controller) {
    if (controller[_byobRequest] === null) {
      return;
    }
    controller[_byobRequest][_controller] = undefined;
    controller[_byobRequest][_view] = null;
    controller[_byobRequest] = null;
  }

  /**
   * @param {ReadableByteStreamController} controller
   * @param {PullIntoDescriptor} firstDescriptor
   */
  function readableByteStreamControllerRespondInClosedState(
    controller,
    firstDescriptor,
  ) {
    assert(firstDescriptor.bytesFilled === 0);
    if (firstDescriptor.readerType === "none") {
      readableByteStreamControllerShiftPendingPullInto(controller);
    }
    const stream = controller[_stream];
    if (readableStreamHasBYOBReader(stream)) {
      while (readableStreamGetNumReadIntoRequests(stream) > 0) {
        const pullIntoDescriptor =
          readableByteStreamControllerShiftPendingPullInto(controller);
        readableByteStreamControllerCommitPullIntoDescriptor(
          stream,
          pullIntoDescriptor,
        );
      }
    }
  }

  /**
   * @template R
   * @param {ReadableStream<R>} stream
   * @param {PullIntoDescriptor} pullIntoDescriptor
   */
  function readableByteStreamControllerCommitPullIntoDescriptor(
    stream,
    pullIntoDescriptor,
  ) {
    assert(stream[_state] !== "errored");
    assert(pullIntoDescriptor.readerType !== "none");
    let done = false;
    if (stream[_state] === "closed") {
      assert(pullIntoDescriptor.bytesFilled === 0);
      done = true;
    }
    const filledView = readableByteStreamControllerConvertPullIntoDescriptor(
      pullIntoDescriptor,
    );
    if (pullIntoDescriptor.readerType === "default") {
      readableStreamFulfillReadRequest(stream, filledView, done);
    } else {
      assert(pullIntoDescriptor.readerType === "byob");
      readableStreamFulfillReadIntoRequest(stream, filledView, done);
    }
  }

  /**
   * @param {ReadableByteStreamController} controller
   * @param {ArrayBufferView} view
   */
  function readableByteStreamControllerRespondWithNewView(controller, view) {
    assert(controller[_pendingPullIntos].length !== 0);
    assert(!isDetachedBuffer(view.buffer));
    const firstDescriptor = controller[_pendingPullIntos][0];
    const state = controller[_stream][_state];
    if (state === "closed") {
      if (view.byteLength !== 0) {
        throw new TypeError(
          "The view's length must be 0 when calling respondWithNewView() on a closed stream",
        );
      }
    } else {
      assert(state === "readable");
      if (view.byteLength === 0) {
        throw new TypeError(
          "The view's length must be greater than 0 when calling respondWithNewView() on a readable stream",
        );
      }
    }
    if (
      (firstDescriptor.byteOffset + firstDescriptor.bytesFilled) !==
        view.byteOffset
    ) {
      throw new RangeError(
        "The region specified by view does not match byobRequest",
      );
    }
    if (firstDescriptor.bufferByteLength !== view.buffer.byteLength) {
      throw new RangeError(
        "The buffer of view has different capacity than byobRequest",
      );
    }
    if (
      (firstDescriptor.bytesFilled + view.byteLength) >
        firstDescriptor.byteLength
    ) {
      throw new RangeError(
        "The region specified by view is larger than byobRequest",
      );
    }
    const viewByteLength = view.byteLength;
    firstDescriptor.buffer = transferArrayBuffer(view.buffer);
    readableByteStreamControllerRespondInternal(controller, viewByteLength);
  }

  /**
   * @param {ReadableByteStreamController} controller
   * @returns {PullIntoDescriptor}
   */
  function readableByteStreamControllerShiftPendingPullInto(controller) {
    assert(controller[_byobRequest] === null);
    return ArrayPrototypeShift(controller[_pendingPullIntos]);
  }

  /**
   * @param {ReadableByteStreamController} controller
   * @param {PullIntoDescriptor} pullIntoDescriptor
   * @returns {boolean}
   */
  function readableByteStreamControllerFillPullIntoDescriptorFromQueue(
    controller,
    pullIntoDescriptor,
  ) {
    const elementSize = pullIntoDescriptor.elementSize;
    const currentAlignedBytes = pullIntoDescriptor.bytesFilled -
      (pullIntoDescriptor.bytesFilled % elementSize);
    const maxBytesToCopy = MathMin(
      controller[_queueTotalSize],
      pullIntoDescriptor.byteLength - pullIntoDescriptor.bytesFilled,
    );
    const maxBytesFilled = pullIntoDescriptor.bytesFilled + maxBytesToCopy;
    const maxAlignedBytes = maxBytesFilled - (maxBytesFilled % elementSize);
    let totalBytesToCopyRemaining = maxBytesToCopy;
    let ready = false;
    if (maxAlignedBytes > currentAlignedBytes) {
      totalBytesToCopyRemaining = maxAlignedBytes -
        pullIntoDescriptor.bytesFilled;
      ready = true;
    }
    const queue = controller[_queue];
    while (totalBytesToCopyRemaining > 0) {
      const headOfQueue = queue[0];
      const bytesToCopy = MathMin(
        totalBytesToCopyRemaining,
        headOfQueue.byteLength,
      );
      const destStart = pullIntoDescriptor.byteOffset +
        pullIntoDescriptor.bytesFilled;

      const destBuffer = new Uint8Array(
        pullIntoDescriptor.buffer,
        destStart,
        bytesToCopy,
      );
      const srcBuffer = new Uint8Array(
        headOfQueue.buffer,
        headOfQueue.byteOffset,
        bytesToCopy,
      );
      destBuffer.set(srcBuffer);

      if (headOfQueue.byteLength === bytesToCopy) {
        ArrayPrototypeShift(queue);
      } else {
        headOfQueue.byteOffset += bytesToCopy;
        headOfQueue.byteLength -= bytesToCopy;
      }
      controller[_queueTotalSize] -= bytesToCopy;
      readableByteStreamControllerFillHeadPullIntoDescriptor(
        controller,
        bytesToCopy,
        pullIntoDescriptor,
      );
      totalBytesToCopyRemaining -= bytesToCopy;
    }
    if (!ready) {
      assert(controller[_queueTotalSize] === 0);
      assert(pullIntoDescriptor.bytesFilled > 0);
      assert(pullIntoDescriptor.bytesFilled < pullIntoDescriptor.elementSize);
    }
    return ready;
  }

  /**
   * @param {ReadableByteStreamController} controller
   * @param {ReadRequest} readRequest
   * @returns {void}
   */
  function readableByteStreamControllerFillReadRequestFromQueue(
    controller,
    readRequest,
  ) {
    assert(controller[_queueTotalSize] > 0);
    const entry = ArrayPrototypeShift(controller[_queue]);
    controller[_queueTotalSize] -= entry.byteLength;
    readableByteStreamControllerHandleQueueDrain(controller);
    const view = new Uint8Array(
      entry.buffer,
      entry.byteOffset,
      entry.byteLength,
    );
    readRequest.chunkSteps(view);
  }

  /**
   * @param {ReadableByteStreamController} controller
   * @param {number} size
   * @param {PullIntoDescriptor} pullIntoDescriptor
   * @returns {void}
   */
  function readableByteStreamControllerFillHeadPullIntoDescriptor(
    controller,
    size,
    pullIntoDescriptor,
  ) {
    assert(
      controller[_pendingPullIntos].length === 0 ||
        controller[_pendingPullIntos][0] === pullIntoDescriptor,
    );
    assert(controller[_byobRequest] === null);
    pullIntoDescriptor.bytesFilled += size;
  }

  /**
   * @param {PullIntoDescriptor} pullIntoDescriptor
   * @returns {ArrayBufferView}
   */
  function readableByteStreamControllerConvertPullIntoDescriptor(
    pullIntoDescriptor,
  ) {
    const bytesFilled = pullIntoDescriptor.bytesFilled;
    const elementSize = pullIntoDescriptor.elementSize;
    assert(bytesFilled <= pullIntoDescriptor.byteLength);
    assert((bytesFilled % elementSize) === 0);
    const buffer = transferArrayBuffer(pullIntoDescriptor.buffer);
    return new pullIntoDescriptor.viewConstructor(
      buffer,
      pullIntoDescriptor.byteOffset,
      bytesFilled / elementSize,
    );
  }

  /**
   * @template R
   * @param {ReadableStreamDefaultReader<R>} reader
   * @param {ReadRequest<R>} readRequest
   * @returns {void}
   */
  function readableStreamDefaultReaderRead(reader, readRequest) {
    const stream = reader[_stream];
    assert(stream);
    stream[_disturbed] = true;
    if (stream[_state] === "closed") {
      readRequest.closeSteps();
    } else if (stream[_state] === "errored") {
      readRequest.errorSteps(stream[_storedError]);
    } else {
      assert(stream[_state] === "readable");
      stream[_controller][_pullSteps](readRequest);
    }
  }

  /**
   * @template R
   * @param {ReadableStreamDefaultReader<R>} reader
   */
  function readableStreamDefaultReaderRelease(reader) {
    readableStreamReaderGenericRelease(reader);
    const e = new TypeError("The reader was released.");
    readableStreamDefaultReaderErrorReadRequests(reader, e);
  }

  /**
   * @template R
   * @param {ReadableStream<R>} stream
   * @param {any} e
   */
  function readableStreamError(stream, e) {
    assert(stream[_state] === "readable");
    stream[_state] = "errored";
    stream[_storedError] = e;
    /** @type {ReadableStreamDefaultReader<R> | undefined} */
    const reader = stream[_reader];
    if (reader === undefined) {
      return;
    }
    /** @type {Deferred<void>} */
    const closedPromise = reader[_closedPromise];
    closedPromise.reject(e);
    setPromiseIsHandledToTrue(closedPromise.promise);
    if (isReadableStreamDefaultReader(reader)) {
      readableStreamDefaultReaderErrorReadRequests(reader, e);
    } else {
      assert(isReadableStreamBYOBReader(reader));
      readableStreamBYOBReaderErrorReadIntoRequests(reader, e);
    }
  }

  /**
   * @template R
   * @param {ReadableStream<R>} stream
   * @param {R} chunk
   * @param {boolean} done
   */
  function readableStreamFulfillReadIntoRequest(stream, chunk, done) {
    assert(readableStreamHasBYOBReader(stream));
    /** @type {ReadableStreamDefaultReader<R>} */
    const reader = stream[_reader];
    assert(reader[_readIntoRequests].length !== 0);
    /** @type {ReadIntoRequest} */
    const readIntoRequest = ArrayPrototypeShift(reader[_readIntoRequests]);
    if (done) {
      readIntoRequest.closeSteps(chunk);
    } else {
      readIntoRequest.chunkSteps(chunk);
    }
  }

  /**
   * @template R
   * @param {ReadableStream<R>} stream
   * @param {R} chunk
   * @param {boolean} done
   */
  function readableStreamFulfillReadRequest(stream, chunk, done) {
    assert(readableStreamHasDefaultReader(stream) === true);
    /** @type {ReadableStreamDefaultReader<R>} */
    const reader = stream[_reader];
    assert(reader[_readRequests].length);
    /** @type {ReadRequest<R>} */
    const readRequest = ArrayPrototypeShift(reader[_readRequests]);
    if (done) {
      readRequest.closeSteps();
    } else {
      readRequest.chunkSteps(chunk);
    }
  }

  /**
   * @param {ReadableStream} stream
   * @return {number}
   */
  function readableStreamGetNumReadIntoRequests(stream) {
    assert(readableStreamHasBYOBReader(stream) === true);
    return stream[_reader][_readIntoRequests].length;
  }

  /**
   * @param {ReadableStream} stream
   * @return {number}
   */
  function readableStreamGetNumReadRequests(stream) {
    assert(readableStreamHasDefaultReader(stream) === true);
    return stream[_reader][_readRequests].length;
  }

  /**
   * @param {ReadableStream} stream
   * @returns {boolean}
   */
  function readableStreamHasBYOBReader(stream) {
    const reader = stream[_reader];
    if (reader === undefined) {
      return false;
    }
    if (isReadableStreamBYOBReader(reader)) {
      return true;
    }
    return false;
  }

  /**
   * @param {ReadableStream} stream
   * @returns {boolean}
   */
  function readableStreamHasDefaultReader(stream) {
    const reader = stream[_reader];
    if (reader === undefined) {
      return false;
    }
    if (isReadableStreamDefaultReader(reader)) {
      return true;
    }
    return false;
  }

  /**
   * @template T
   * @param {ReadableStream<T>} source
   * @param {WritableStream<T>} dest
   * @param {boolean} preventClose
   * @param {boolean} preventAbort
   * @param {boolean} preventCancel
   * @param {AbortSignal=} signal
   * @returns {Promise<void>}
   */
  function readableStreamPipeTo(
    source,
    dest,
    preventClose,
    preventAbort,
    preventCancel,
    signal,
  ) {
    assert(isReadableStream(source));
    assert(isWritableStream(dest));
    assert(
      typeof preventClose === "boolean" && typeof preventAbort === "boolean" &&
        typeof preventCancel === "boolean",
    );
    assert(
      signal === undefined ||
        ObjectPrototypeIsPrototypeOf(AbortSignalPrototype, signal),
    );
    assert(!isReadableStreamLocked(source));
    assert(!isWritableStreamLocked(dest));
    // We use acquireReadableStreamDefaultReader even in case of ReadableByteStreamController
    // as the spec allows us, and the only reason to use BYOBReader is to do some smart things
    // with it, but the spec does not specify what things, so to simplify we stick to DefaultReader.
    const reader = acquireReadableStreamDefaultReader(source);
    const writer = acquireWritableStreamDefaultWriter(dest);
    source[_disturbed] = true;
    let shuttingDown = false;
    let currentWrite = resolvePromiseWith(undefined);
    /** @type {Deferred<void>} */
    const promise = new Deferred();
    /** @type {() => void} */
    let abortAlgorithm;
    if (signal) {
      abortAlgorithm = () => {
        const error = signal.reason;
        /** @type {Array<() => Promise<void>>} */
        const actions = [];
        if (preventAbort === false) {
          ArrayPrototypePush(actions, () => {
            if (dest[_state] === "writable") {
              return writableStreamAbort(dest, error);
            } else {
              return resolvePromiseWith(undefined);
            }
          });
        }
        if (preventCancel === false) {
          ArrayPrototypePush(actions, () => {
            if (source[_state] === "readable") {
              return readableStreamCancel(source, error);
            } else {
              return resolvePromiseWith(undefined);
            }
          });
        }
        shutdownWithAction(
          () => PromiseAll(ArrayPrototypeMap(actions, (action) => action())),
          true,
          error,
        );
      };

      if (signal.aborted) {
        abortAlgorithm();
        return promise.promise;
      }
      signal[add](abortAlgorithm);
    }

    function pipeLoop() {
      return new Promise((resolveLoop, rejectLoop) => {
        /** @param {boolean} done */
        function next(done) {
          if (done) {
            resolveLoop();
          } else {
            uponPromise(pipeStep(), next, rejectLoop);
          }
        }
        next(false);
      });
    }

    /** @returns {Promise<boolean>} */
    function pipeStep() {
      if (shuttingDown === true) {
        return resolvePromiseWith(true);
      }

      return transformPromiseWith(writer[_readyPromise].promise, () => {
        return new Promise((resolveRead, rejectRead) => {
          readableStreamDefaultReaderRead(
            reader,
            {
              chunkSteps(chunk) {
                currentWrite = transformPromiseWith(
                  writableStreamDefaultWriterWrite(writer, chunk),
                  undefined,
                  () => {},
                );
                resolveRead(false);
              },
              closeSteps() {
                resolveRead(true);
              },
              errorSteps: rejectRead,
            },
          );
        });
      });
    }

    isOrBecomesErrored(
      source,
      reader[_closedPromise].promise,
      (storedError) => {
        if (preventAbort === false) {
          shutdownWithAction(
            () => writableStreamAbort(dest, storedError),
            true,
            storedError,
          );
        } else {
          shutdown(true, storedError);
        }
      },
    );

    isOrBecomesErrored(dest, writer[_closedPromise].promise, (storedError) => {
      if (preventCancel === false) {
        shutdownWithAction(
          () => readableStreamCancel(source, storedError),
          true,
          storedError,
        );
      } else {
        shutdown(true, storedError);
      }
    });

    isOrBecomesClosed(source, reader[_closedPromise].promise, () => {
      if (preventClose === false) {
        shutdownWithAction(() =>
          writableStreamDefaultWriterCloseWithErrorPropagation(writer)
        );
      } else {
        shutdown();
      }
    });

    if (
      writableStreamCloseQueuedOrInFlight(dest) === true ||
      dest[_state] === "closed"
    ) {
      const destClosed = new TypeError(
        "The destination writable stream closed before all the data could be piped to it.",
      );
      if (preventCancel === false) {
        shutdownWithAction(
          () => readableStreamCancel(source, destClosed),
          true,
          destClosed,
        );
      } else {
        shutdown(true, destClosed);
      }
    }

    setPromiseIsHandledToTrue(pipeLoop());

    return promise.promise;

    /** @returns {Promise<void>} */
    function waitForWritesToFinish() {
      const oldCurrentWrite = currentWrite;
      return transformPromiseWith(
        currentWrite,
        () =>
          oldCurrentWrite !== currentWrite
            ? waitForWritesToFinish()
            : undefined,
      );
    }

    /**
     * @param {ReadableStream | WritableStream} stream
     * @param {Promise<any>} promise
     * @param {(e: any) => void} action
     */
    function isOrBecomesErrored(stream, promise, action) {
      if (stream[_state] === "errored") {
        action(stream[_storedError]);
      } else {
        uponRejection(promise, action);
      }
    }

    /**
     * @param {ReadableStream} stream
     * @param {Promise<any>} promise
     * @param {() => void} action
     */
    function isOrBecomesClosed(stream, promise, action) {
      if (stream[_state] === "closed") {
        action();
      } else {
        uponFulfillment(promise, action);
      }
    }

    /**
     * @param {() => Promise<void[] | void>} action
     * @param {boolean=} originalIsError
     * @param {any=} originalError
     */
    function shutdownWithAction(action, originalIsError, originalError) {
      function doTheRest() {
        uponPromise(
          action(),
          () => finalize(originalIsError, originalError),
          (newError) => finalize(true, newError),
        );
      }

      if (shuttingDown === true) {
        return;
      }
      shuttingDown = true;

      if (
        dest[_state] === "writable" &&
        writableStreamCloseQueuedOrInFlight(dest) === false
      ) {
        uponFulfillment(waitForWritesToFinish(), doTheRest);
      } else {
        doTheRest();
      }
    }

    /**
     * @param {boolean=} isError
     * @param {any=} error
     */
    function shutdown(isError, error) {
      if (shuttingDown) {
        return;
      }
      shuttingDown = true;
      if (
        dest[_state] === "writable" &&
        writableStreamCloseQueuedOrInFlight(dest) === false
      ) {
        uponFulfillment(
          waitForWritesToFinish(),
          () => finalize(isError, error),
        );
      } else {
        finalize(isError, error);
      }
    }

    /**
     * @param {boolean=} isError
     * @param {any=} error
     */
    function finalize(isError, error) {
      writableStreamDefaultWriterRelease(writer);
      readableStreamDefaultReaderRelease(reader);

      if (signal !== undefined) {
        signal[remove](abortAlgorithm);
      }
      if (isError) {
        promise.reject(error);
      } else {
        promise.resolve(undefined);
      }
    }
  }

  /**
   * @param {ReadableStreamGenericReader<any> | ReadableStreamBYOBReader} reader
   * @param {any} reason
   * @returns {Promise<void>}
   */
  function readableStreamReaderGenericCancel(reader, reason) {
    const stream = reader[_stream];
    assert(stream !== undefined);
    return readableStreamCancel(stream, reason);
  }

  /**
   * @template R
   * @param {ReadableStreamDefaultReader<R> | ReadableStreamBYOBReader} reader
   * @param {ReadableStream<R>} stream
   */
  function readableStreamReaderGenericInitialize(reader, stream) {
    reader[_stream] = stream;
    stream[_reader] = reader;
    if (stream[_state] === "readable") {
      reader[_closedPromise] = new Deferred();
    } else if (stream[_state] === "closed") {
      reader[_closedPromise] = new Deferred();
      reader[_closedPromise].resolve(undefined);
    } else {
      assert(stream[_state] === "errored");
      reader[_closedPromise] = new Deferred();
      reader[_closedPromise].reject(stream[_storedError]);
      setPromiseIsHandledToTrue(reader[_closedPromise].promise);
    }
  }

  /**
   * @template R
   * @param {ReadableStreamGenericReader<R> | ReadableStreamBYOBReader} reader
   */
  function readableStreamReaderGenericRelease(reader) {
    const stream = reader[_stream];
    assert(stream !== undefined);
    assert(stream[_reader] === reader);
    if (stream[_state] === "readable") {
      reader[_closedPromise].reject(
        new TypeError(
          "Reader was released and can no longer be used to monitor the stream's closedness.",
        ),
      );
    } else {
      reader[_closedPromise] = new Deferred();
      reader[_closedPromise].reject(
        new TypeError(
          "Reader was released and can no longer be used to monitor the stream's closedness.",
        ),
      );
    }
    setPromiseIsHandledToTrue(reader[_closedPromise].promise);
    stream[_controller][_releaseSteps]();
    stream[_reader] = undefined;
    reader[_stream] = undefined;
  }

  /**
   * @param {ReadableStreamBYOBReader} reader
   * @param {any} e
   */
  function readableStreamBYOBReaderErrorReadIntoRequests(reader, e) {
    const readIntoRequests = reader[_readIntoRequests];
    reader[_readIntoRequests] = [];
    for (const readIntoRequest of readIntoRequests) {
      readIntoRequest.errorSteps(e);
    }
  }

  /**
   * @template R
   * @param {ReadableStream<R>} stream
   * @param {boolean} cloneForBranch2
   * @returns {[ReadableStream<R>, ReadableStream<R>]}
   */
  function readableStreamTee(stream, cloneForBranch2) {
    assert(isReadableStream(stream));
    assert(typeof cloneForBranch2 === "boolean");
    if (
      ObjectPrototypeIsPrototypeOf(
        ReadableByteStreamControllerPrototype,
        stream[_controller],
      )
    ) {
      return readableByteStreamTee(stream);
    } else {
      return readableStreamDefaultTee(stream, cloneForBranch2);
    }
  }

  /**
   * @template R
   * @param {ReadableStream<R>} stream
   * @param {boolean} cloneForBranch2
   * @returns {[ReadableStream<R>, ReadableStream<R>]}
   */
  function readableStreamDefaultTee(stream, cloneForBranch2) {
    assert(isReadableStream(stream));
    assert(typeof cloneForBranch2 === "boolean");
    const reader = acquireReadableStreamDefaultReader(stream);
    let reading = false;
    let canceled1 = false;
    let canceled2 = false;
    /** @type {any} */
    let reason1;
    /** @type {any} */
    let reason2;
    /** @type {ReadableStream<R>} */
    // deno-lint-ignore prefer-const
    let branch1;
    /** @type {ReadableStream<R>} */
    // deno-lint-ignore prefer-const
    let branch2;

    /** @type {Deferred<void>} */
    const cancelPromise = new Deferred();

    function pullAlgorithm() {
      if (reading === true) {
        return resolvePromiseWith(undefined);
      }
      reading = true;
      /** @type {ReadRequest<R>} */
      const readRequest = {
        chunkSteps(value) {
          queueMicrotask(() => {
            reading = false;
            const value1 = value;
            const value2 = value;

            // TODO(lucacasonato): respect clonedForBranch2.

            if (canceled1 === false) {
              readableStreamDefaultControllerEnqueue(
                /** @type {ReadableStreamDefaultController<any>} */ branch1[
                  _controller
                ],
                value1,
              );
            }
            if (canceled2 === false) {
              readableStreamDefaultControllerEnqueue(
                /** @type {ReadableStreamDefaultController<any>} */ branch2[
                  _controller
                ],
                value2,
              );
            }
          });
        },
        closeSteps() {
          reading = false;
          if (canceled1 === false) {
            readableStreamDefaultControllerClose(
              /** @type {ReadableStreamDefaultController<any>} */ branch1[
                _controller
              ],
            );
          }
          if (canceled2 === false) {
            readableStreamDefaultControllerClose(
              /** @type {ReadableStreamDefaultController<any>} */ branch2[
                _controller
              ],
            );
          }
          cancelPromise.resolve(undefined);
        },
        errorSteps() {
          reading = false;
        },
      };
      readableStreamDefaultReaderRead(reader, readRequest);
      return resolvePromiseWith(undefined);
    }

    /**
     * @param {any} reason
     * @returns {Promise<void>}
     */
    function cancel1Algorithm(reason) {
      canceled1 = true;
      reason1 = reason;
      if (canceled2 === true) {
        const compositeReason = [reason1, reason2];
        const cancelResult = readableStreamCancel(stream, compositeReason);
        cancelPromise.resolve(cancelResult);
      }
      return cancelPromise.promise;
    }

    /**
     * @param {any} reason
     * @returns {Promise<void>}
     */
    function cancel2Algorithm(reason) {
      canceled2 = true;
      reason2 = reason;
      if (canceled1 === true) {
        const compositeReason = [reason1, reason2];
        const cancelResult = readableStreamCancel(stream, compositeReason);
        cancelPromise.resolve(cancelResult);
      }
      return cancelPromise.promise;
    }

    function startAlgorithm() {}

    branch1 = createReadableStream(
      startAlgorithm,
      pullAlgorithm,
      cancel1Algorithm,
    );
    branch2 = createReadableStream(
      startAlgorithm,
      pullAlgorithm,
      cancel2Algorithm,
    );

    uponRejection(reader[_closedPromise].promise, (r) => {
      readableStreamDefaultControllerError(
        /** @type {ReadableStreamDefaultController<any>} */ branch1[
          _controller
        ],
        r,
      );
      readableStreamDefaultControllerError(
        /** @type {ReadableStreamDefaultController<any>} */ branch2[
          _controller
        ],
        r,
      );
      if (canceled1 === false || canceled2 === false) {
        cancelPromise.resolve(undefined);
      }
    });

    return [branch1, branch2];
  }

  /**
   * @template R
   * @param {ReadableStream<R>} stream
   * @returns {[ReadableStream<R>, ReadableStream<R>]}
   */
  function readableByteStreamTee(stream) {
    assert(isReadableStream(stream));
    assert(
      ObjectPrototypeIsPrototypeOf(
        ReadableByteStreamControllerPrototype,
        stream[_controller],
      ),
    );
    let reader = acquireReadableStreamDefaultReader(stream);
    let reading = false;
    let readAgainForBranch1 = false;
    let readAgainForBranch2 = false;
    let canceled1 = false;
    let canceled2 = false;
    let reason1 = undefined;
    let reason2 = undefined;
    let branch1 = undefined;
    let branch2 = undefined;
    /** @type {Deferred<void>} */
    const cancelPromise = new Deferred();

    /**
     * @param {ReadableStreamBYOBReader} thisReader
     */
    function forwardReaderError(thisReader) {
      PromisePrototypeCatch(thisReader[_closedPromise].promise, (e) => {
        if (thisReader !== reader) {
          return;
        }
        readableByteStreamControllerError(branch1[_controller], e);
        readableByteStreamControllerError(branch2[_controller], e);
        if (!canceled1 || !canceled2) {
          cancelPromise.resolve(undefined);
        }
      });
    }

    function pullWithDefaultReader() {
      if (isReadableStreamBYOBReader(reader)) {
        assert(reader[_readIntoRequests].length === 0);
        readableStreamBYOBReaderRelease(reader);
        reader = acquireReadableStreamDefaultReader(stream);
        forwardReaderError(reader);
      }

      /** @type {ReadRequest} */
      const readRequest = {
        chunkSteps(chunk) {
          queueMicrotask(() => {
            readAgainForBranch1 = false;
            readAgainForBranch2 = false;
            const chunk1 = chunk;
            let chunk2 = chunk;
            if (!canceled1 && !canceled2) {
              try {
                chunk2 = cloneAsUint8Array(chunk);
              } catch (e) {
                readableByteStreamControllerError(branch1[_controller], e);
                readableByteStreamControllerError(branch2[_controller], e);
                cancelPromise.resolve(readableStreamCancel(stream, e));
                return;
              }
            }
            if (!canceled1) {
              readableByteStreamControllerEnqueue(branch1[_controller], chunk1);
            }
            if (!canceled2) {
              readableByteStreamControllerEnqueue(branch2[_controller], chunk2);
            }
            reading = false;
            if (readAgainForBranch1) {
              pull1Algorithm();
            } else if (readAgainForBranch2) {
              pull2Algorithm();
            }
          });
        },
        closeSteps() {
          reading = false;
          if (!canceled1) {
            readableByteStreamControllerClose(branch1[_controller]);
          }
          if (!canceled2) {
            readableByteStreamControllerClose(branch2[_controller]);
          }
          if (branch1[_controller][_pendingPullIntos].length !== 0) {
            readableByteStreamControllerRespond(branch1[_controller], 0);
          }
          if (branch2[_controller][_pendingPullIntos].length !== 0) {
            readableByteStreamControllerRespond(branch2[_controller], 0);
          }
          if (!canceled1 || !canceled2) {
            cancelPromise.resolve(undefined);
          }
        },
        errorSteps() {
          reading = false;
        },
      };
      readableStreamDefaultReaderRead(reader, readRequest);
    }

    function pullWithBYOBReader(view, forBranch2) {
      if (isReadableStreamDefaultReader(reader)) {
        assert(reader[_readRequests].length === 0);
        readableStreamDefaultReaderRelease(reader);
        reader = acquireReadableStreamBYOBReader(stream);
        forwardReaderError(reader);
      }
      const byobBranch = forBranch2 ? branch2 : branch1;
      const otherBranch = forBranch2 ? branch1 : branch2;

      /** @type {ReadIntoRequest} */
      const readIntoRequest = {
        chunkSteps(chunk) {
          queueMicrotask(() => {
            readAgainForBranch1 = false;
            readAgainForBranch2 = false;
            const byobCanceled = forBranch2 ? canceled2 : canceled1;
            const otherCanceled = forBranch2 ? canceled1 : canceled2;
            if (!otherCanceled) {
              let clonedChunk;
              try {
                clonedChunk = cloneAsUint8Array(chunk);
              } catch (e) {
                readableByteStreamControllerError(byobBranch[_controller], e);
                readableByteStreamControllerError(otherBranch[_controller], e);
                cancelPromise.resolve(readableStreamCancel(stream, e));
                return;
              }
              if (!byobCanceled) {
                readableByteStreamControllerRespondWithNewView(
                  byobBranch[_controller],
                  chunk,
                );
              }
              readableByteStreamControllerEnqueue(
                otherBranch[_controller],
                clonedChunk,
              );
            } else if (!byobCanceled) {
              readableByteStreamControllerRespondWithNewView(
                byobBranch[_controller],
                chunk,
              );
            }
            reading = false;
            if (readAgainForBranch1) {
              pull1Algorithm();
            } else if (readAgainForBranch2) {
              pull2Algorithm();
            }
          });
        },
        closeSteps(chunk) {
          reading = false;
          const byobCanceled = forBranch2 ? canceled2 : canceled1;
          const otherCanceled = forBranch2 ? canceled1 : canceled2;
          if (!byobCanceled) {
            readableByteStreamControllerClose(byobBranch[_controller]);
          }
          if (!otherCanceled) {
            readableByteStreamControllerClose(otherBranch[_controller]);
          }
          if (chunk !== undefined) {
            assert(chunk.byteLength === 0);
            if (!byobCanceled) {
              readableByteStreamControllerRespondWithNewView(
                byobBranch[_controller],
                chunk,
              );
            }
            if (
              !otherCanceled &&
              otherBranch[_controller][_pendingPullIntos].length !== 0
            ) {
              readableByteStreamControllerRespond(otherBranch[_controller], 0);
            }
          }
          if (!byobCanceled || !otherCanceled) {
            cancelPromise.resolve(undefined);
          }
        },
        errorSteps() {
          reading = false;
        },
      };
      readableStreamBYOBReaderRead(reader, view, readIntoRequest);
    }

    function pull1Algorithm() {
      if (reading) {
        readAgainForBranch1 = true;
        return PromiseResolve(undefined);
      }
      reading = true;
      const byobRequest = readableByteStreamControllerGetBYOBRequest(
        branch1[_controller],
      );
      if (byobRequest === null) {
        pullWithDefaultReader();
      } else {
        pullWithBYOBReader(byobRequest[_view], false);
      }
      return PromiseResolve(undefined);
    }

    function pull2Algorithm() {
      if (reading) {
        readAgainForBranch2 = true;
        return PromiseResolve(undefined);
      }
      reading = true;
      const byobRequest = readableByteStreamControllerGetBYOBRequest(
        branch2[_controller],
      );
      if (byobRequest === null) {
        pullWithDefaultReader();
      } else {
        pullWithBYOBReader(byobRequest[_view], true);
      }
      return PromiseResolve(undefined);
    }

    function cancel1Algorithm(reason) {
      canceled1 = true;
      reason1 = reason;
      if (canceled2) {
        const compositeReason = [reason1, reason2];
        const cancelResult = readableStreamCancel(stream, compositeReason);
        cancelPromise.resolve(cancelResult);
      }
      return cancelPromise.promise;
    }

    function cancel2Algorithm(reason) {
      canceled2 = true;
      reason2 = reason;
      if (canceled1) {
        const compositeReason = [reason1, reason2];
        const cancelResult = readableStreamCancel(stream, compositeReason);
        cancelPromise.resolve(cancelResult);
      }
      return cancelPromise.promise;
    }

    function startAlgorithm() {
      return undefined;
    }

    branch1 = createReadableByteStream(
      startAlgorithm,
      pull1Algorithm,
      cancel1Algorithm,
    );
    branch2 = createReadableByteStream(
      startAlgorithm,
      pull2Algorithm,
      cancel2Algorithm,
    );
    forwardReaderError(reader);
    return [branch1, branch2];
  }

  /**
   * @param {ReadableStream<ArrayBuffer>} stream
   * @param {ReadableByteStreamController} controller
   * @param {() => void} startAlgorithm
   * @param {() => Promise<void>} pullAlgorithm
   * @param {(reason: any) => Promise<void>} cancelAlgorithm
   * @param {number} highWaterMark
   * @param {number | undefined} autoAllocateChunkSize
   */
  function setUpReadableByteStreamController(
    stream,
    controller,
    startAlgorithm,
    pullAlgorithm,
    cancelAlgorithm,
    highWaterMark,
    autoAllocateChunkSize,
  ) {
    assert(stream[_controller] === undefined);
    if (autoAllocateChunkSize !== undefined) {
      assert(NumberIsInteger(autoAllocateChunkSize));
      assert(autoAllocateChunkSize >= 0);
    }
    controller[_stream] = stream;
    controller[_pullAgain] = controller[_pulling] = false;
    controller[_byobRequest] = null;
    resetQueue(controller);
    controller[_closeRequested] = controller[_started] = false;
    controller[_strategyHWM] = highWaterMark;
    controller[_pullAlgorithm] = pullAlgorithm;
    controller[_cancelAlgorithm] = cancelAlgorithm;
    controller[_autoAllocateChunkSize] = autoAllocateChunkSize;
    controller[_pendingPullIntos] = [];
    stream[_controller] = controller;
    const startResult = startAlgorithm();
    const startPromise = resolvePromiseWith(startResult);
    setPromiseIsHandledToTrue(
      PromisePrototypeThen(
        startPromise,
        () => {
          controller[_started] = true;
          assert(controller[_pulling] === false);
          assert(controller[_pullAgain] === false);
          readableByteStreamControllerCallPullIfNeeded(controller);
        },
        (r) => {
          readableByteStreamControllerError(controller, r);
        },
      ),
    );
  }

  /**
   * @param {ReadableStream<ArrayBuffer>} stream
   * @param {UnderlyingSource<ArrayBuffer>} underlyingSource
   * @param {UnderlyingSource<ArrayBuffer>} underlyingSourceDict
   * @param {number} highWaterMark
   */
  function setUpReadableByteStreamControllerFromUnderlyingSource(
    stream,
    underlyingSource,
    underlyingSourceDict,
    highWaterMark,
  ) {
    const controller = webidl.createBranded(ReadableByteStreamController);
    /** @type {() => void} */
    let startAlgorithm = () => undefined;
    /** @type {() => Promise<void>} */
    let pullAlgorithm = () => resolvePromiseWith(undefined);
    /** @type {(reason: any) => Promise<void>} */
    let cancelAlgorithm = (_reason) => resolvePromiseWith(undefined);
    if (underlyingSourceDict.start !== undefined) {
      startAlgorithm = () =>
        webidl.invokeCallbackFunction(
          underlyingSourceDict.start,
          [controller],
          underlyingSource,
          webidl.converters.any,
          {
            prefix:
              "Failed to call 'startAlgorithm' on 'ReadableByteStreamController'",
          },
        );
    }
    if (underlyingSourceDict.pull !== undefined) {
      pullAlgorithm = () =>
        webidl.invokeCallbackFunction(
          underlyingSourceDict.pull,
          [controller],
          underlyingSource,
          webidl.converters["Promise<undefined>"],
          {
            prefix:
              "Failed to call 'pullAlgorithm' on 'ReadableByteStreamController'",
            returnsPromise: true,
          },
        );
    }
    if (underlyingSourceDict.cancel !== undefined) {
      cancelAlgorithm = (reason) =>
        webidl.invokeCallbackFunction(
          underlyingSourceDict.cancel,
          [reason],
          underlyingSource,
          webidl.converters["Promise<undefined>"],
          {
            prefix:
              "Failed to call 'cancelAlgorithm' on 'ReadableByteStreamController'",
            returnsPromise: true,
          },
        );
    }
    const autoAllocateChunkSize = underlyingSourceDict["autoAllocateChunkSize"];
    if (autoAllocateChunkSize === 0) {
      throw new TypeError("autoAllocateChunkSize must be greater than 0");
    }
    setUpReadableByteStreamController(
      stream,
      controller,
      startAlgorithm,
      pullAlgorithm,
      cancelAlgorithm,
      highWaterMark,
      autoAllocateChunkSize,
    );
  }

  /**
   * @template R
   * @param {ReadableStream<R>} stream
   * @param {ReadableStreamDefaultController<R>} controller
   * @param {(controller: ReadableStreamDefaultController<R>) => void | Promise<void>} startAlgorithm
   * @param {(controller: ReadableStreamDefaultController<R>) => Promise<void>} pullAlgorithm
   * @param {(reason: any) => Promise<void>} cancelAlgorithm
   * @param {number} highWaterMark
   * @param {(chunk: R) => number} sizeAlgorithm
   */
  function setUpReadableStreamDefaultController(
    stream,
    controller,
    startAlgorithm,
    pullAlgorithm,
    cancelAlgorithm,
    highWaterMark,
    sizeAlgorithm,
  ) {
    assert(stream[_controller] === undefined);
    controller[_stream] = stream;
    resetQueue(controller);
    controller[_started] =
      controller[_closeRequested] =
      controller[_pullAgain] =
      controller[_pulling] =
        false;
    controller[_strategySizeAlgorithm] = sizeAlgorithm;
    controller[_strategyHWM] = highWaterMark;
    controller[_pullAlgorithm] = pullAlgorithm;
    controller[_cancelAlgorithm] = cancelAlgorithm;
    stream[_controller] = controller;
    const startResult = startAlgorithm(controller);
    const startPromise = resolvePromiseWith(startResult);
    uponPromise(startPromise, () => {
      controller[_started] = true;
      assert(controller[_pulling] === false);
      assert(controller[_pullAgain] === false);
      readableStreamDefaultControllerCallPullIfNeeded(controller);
    }, (r) => {
      readableStreamDefaultControllerError(controller, r);
    });
  }

  /**
   * @template R
   * @param {ReadableStream<R>} stream
   * @param {UnderlyingSource<R>} underlyingSource
   * @param {UnderlyingSource<R>} underlyingSourceDict
   * @param {number} highWaterMark
   * @param {(chunk: R) => number} sizeAlgorithm
   */
  function setUpReadableStreamDefaultControllerFromUnderlyingSource(
    stream,
    underlyingSource,
    underlyingSourceDict,
    highWaterMark,
    sizeAlgorithm,
  ) {
    const controller = webidl.createBranded(ReadableStreamDefaultController);
    /** @type {() => Promise<void>} */
    let startAlgorithm = () => undefined;
    /** @type {() => Promise<void>} */
    let pullAlgorithm = () => resolvePromiseWith(undefined);
    /** @type {(reason?: any) => Promise<void>} */
    let cancelAlgorithm = () => resolvePromiseWith(undefined);
    if (underlyingSourceDict.start !== undefined) {
      startAlgorithm = () =>
        webidl.invokeCallbackFunction(
          underlyingSourceDict.start,
          [controller],
          underlyingSource,
          webidl.converters.any,
          {
            prefix:
              "Failed to call 'startAlgorithm' on 'ReadableStreamDefaultController'",
          },
        );
    }
    if (underlyingSourceDict.pull !== undefined) {
      pullAlgorithm = () =>
        webidl.invokeCallbackFunction(
          underlyingSourceDict.pull,
          [controller],
          underlyingSource,
          webidl.converters["Promise<undefined>"],
          {
            prefix:
              "Failed to call 'pullAlgorithm' on 'ReadableStreamDefaultController'",
            returnsPromise: true,
          },
        );
    }
    if (underlyingSourceDict.cancel !== undefined) {
      cancelAlgorithm = (reason) =>
        webidl.invokeCallbackFunction(
          underlyingSourceDict.cancel,
          [reason],
          underlyingSource,
          webidl.converters["Promise<undefined>"],
          {
            prefix:
              "Failed to call 'cancelAlgorithm' on 'ReadableStreamDefaultController'",
            returnsPromise: true,
          },
        );
    }
    setUpReadableStreamDefaultController(
      stream,
      controller,
      startAlgorithm,
      pullAlgorithm,
      cancelAlgorithm,
      highWaterMark,
      sizeAlgorithm,
    );
  }

  /**
   * @template R
   * @param {ReadableStreamBYOBReader} reader
   * @param {ReadableStream<R>} stream
   */
  function setUpReadableStreamBYOBReader(reader, stream) {
    if (isReadableStreamLocked(stream)) {
      throw new TypeError("ReadableStream is locked.");
    }
    if (
      !(ObjectPrototypeIsPrototypeOf(
        ReadableByteStreamControllerPrototype,
        stream[_controller],
      ))
    ) {
      throw new TypeError("Cannot use a BYOB reader with a non-byte stream");
    }
    readableStreamReaderGenericInitialize(reader, stream);
    reader[_readIntoRequests] = [];
  }

  /**
   * @template R
   * @param {ReadableStreamDefaultReader<R>} reader
   * @param {ReadableStream<R>} stream
   */
  function setUpReadableStreamDefaultReader(reader, stream) {
    if (isReadableStreamLocked(stream)) {
      throw new TypeError("ReadableStream is locked.");
    }
    readableStreamReaderGenericInitialize(reader, stream);
    reader[_readRequests] = [];
  }

  /**
   * @template O
   * @param {TransformStream<any, O>} stream
   * @param {TransformStreamDefaultController<O>} controller
   * @param {(chunk: O, controller: TransformStreamDefaultController<O>) => Promise<void>} transformAlgorithm
   * @param {(controller: TransformStreamDefaultController<O>) => Promise<void>} flushAlgorithm
   */
  function setUpTransformStreamDefaultController(
    stream,
    controller,
    transformAlgorithm,
    flushAlgorithm,
  ) {
    assert(ObjectPrototypeIsPrototypeOf(TransformStreamPrototype, stream));
    assert(stream[_controller] === undefined);
    controller[_stream] = stream;
    stream[_controller] = controller;
    controller[_transformAlgorithm] = transformAlgorithm;
    controller[_flushAlgorithm] = flushAlgorithm;
  }

  /**
   * @template I
   * @template O
   * @param {TransformStream<I, O>} stream
   * @param {Transformer<I, O>} transformer
   * @param {Transformer<I, O>} transformerDict
   */
  function setUpTransformStreamDefaultControllerFromTransformer(
    stream,
    transformer,
    transformerDict,
  ) {
    /** @type {TransformStreamDefaultController<O>} */
    const controller = webidl.createBranded(TransformStreamDefaultController);
    /** @type {(chunk: O, controller: TransformStreamDefaultController<O>) => Promise<void>} */
    let transformAlgorithm = (chunk) => {
      try {
        transformStreamDefaultControllerEnqueue(controller, chunk);
      } catch (e) {
        return PromiseReject(e);
      }
      return resolvePromiseWith(undefined);
    };
    /** @type {(controller: TransformStreamDefaultController<O>) => Promise<void>} */
    let flushAlgorithm = () => resolvePromiseWith(undefined);
    if (transformerDict.transform !== undefined) {
      transformAlgorithm = (chunk, controller) =>
        webidl.invokeCallbackFunction(
          transformerDict.transform,
          [chunk, controller],
          transformer,
          webidl.converters["Promise<undefined>"],
          {
            prefix:
              "Failed to call 'transformAlgorithm' on 'TransformStreamDefaultController'",
            returnsPromise: true,
          },
        );
    }
    if (transformerDict.flush !== undefined) {
      flushAlgorithm = (controller) =>
        webidl.invokeCallbackFunction(
          transformerDict.flush,
          [controller],
          transformer,
          webidl.converters["Promise<undefined>"],
          {
            prefix:
              "Failed to call 'flushAlgorithm' on 'TransformStreamDefaultController'",
            returnsPromise: true,
          },
        );
    }
    setUpTransformStreamDefaultController(
      stream,
      controller,
      transformAlgorithm,
      flushAlgorithm,
    );
  }

  /**
   * @template W
   * @param {WritableStream<W>} stream
   * @param {WritableStreamDefaultController<W>} controller
   * @param {(controller: WritableStreamDefaultController<W>) => Promise<void>} startAlgorithm
   * @param {(chunk: W, controller: WritableStreamDefaultController<W>) => Promise<void>} writeAlgorithm
   * @param {() => Promise<void>} closeAlgorithm
   * @param {(reason?: any) => Promise<void>} abortAlgorithm
   * @param {number} highWaterMark
   * @param {(chunk: W) => number} sizeAlgorithm
   */
  function setUpWritableStreamDefaultController(
    stream,
    controller,
    startAlgorithm,
    writeAlgorithm,
    closeAlgorithm,
    abortAlgorithm,
    highWaterMark,
    sizeAlgorithm,
  ) {
    assert(isWritableStream(stream));
    assert(stream[_controller] === undefined);
    controller[_stream] = stream;
    stream[_controller] = controller;
    resetQueue(controller);
    controller[_signal] = newSignal();
    controller[_started] = false;
    controller[_strategySizeAlgorithm] = sizeAlgorithm;
    controller[_strategyHWM] = highWaterMark;
    controller[_writeAlgorithm] = writeAlgorithm;
    controller[_closeAlgorithm] = closeAlgorithm;
    controller[_abortAlgorithm] = abortAlgorithm;
    const backpressure = writableStreamDefaultControllerGetBackpressure(
      controller,
    );
    writableStreamUpdateBackpressure(stream, backpressure);
    const startResult = startAlgorithm(controller);
    const startPromise = resolvePromiseWith(startResult);
    uponPromise(startPromise, () => {
      assert(stream[_state] === "writable" || stream[_state] === "erroring");
      controller[_started] = true;
      writableStreamDefaultControllerAdvanceQueueIfNeeded(controller);
    }, (r) => {
      assert(stream[_state] === "writable" || stream[_state] === "erroring");
      controller[_started] = true;
      writableStreamDealWithRejection(stream, r);
    });
  }

  /**
   * @template W
   * @param {WritableStream<W>} stream
   * @param {UnderlyingSink<W>} underlyingSink
   * @param {UnderlyingSink<W>} underlyingSinkDict
   * @param {number} highWaterMark
   * @param {(chunk: W) => number} sizeAlgorithm
   */
  function setUpWritableStreamDefaultControllerFromUnderlyingSink(
    stream,
    underlyingSink,
    underlyingSinkDict,
    highWaterMark,
    sizeAlgorithm,
  ) {
    const controller = webidl.createBranded(WritableStreamDefaultController);
    /** @type {(controller: WritableStreamDefaultController<W>) => any} */
    let startAlgorithm = () => undefined;
    /** @type {(chunk: W, controller: WritableStreamDefaultController<W>) => Promise<void>} */
    let writeAlgorithm = () => resolvePromiseWith(undefined);
    let closeAlgorithm = () => resolvePromiseWith(undefined);
    /** @type {(reason?: any) => Promise<void>} */
    let abortAlgorithm = () => resolvePromiseWith(undefined);

    if (underlyingSinkDict.start !== undefined) {
      startAlgorithm = () =>
        webidl.invokeCallbackFunction(
          underlyingSinkDict.start,
          [controller],
          underlyingSink,
          webidl.converters.any,
          {
            prefix:
              "Failed to call 'startAlgorithm' on 'WritableStreamDefaultController'",
          },
        );
    }
    if (underlyingSinkDict.write !== undefined) {
      writeAlgorithm = (chunk) =>
        webidl.invokeCallbackFunction(
          underlyingSinkDict.write,
          [chunk, controller],
          underlyingSink,
          webidl.converters["Promise<undefined>"],
          {
            prefix:
              "Failed to call 'writeAlgorithm' on 'WritableStreamDefaultController'",
            returnsPromise: true,
          },
        );
    }
    if (underlyingSinkDict.close !== undefined) {
      closeAlgorithm = () =>
        webidl.invokeCallbackFunction(
          underlyingSinkDict.close,
          [],
          underlyingSink,
          webidl.converters["Promise<undefined>"],
          {
            prefix:
              "Failed to call 'closeAlgorithm' on 'WritableStreamDefaultController'",
            returnsPromise: true,
          },
        );
    }
    if (underlyingSinkDict.abort !== undefined) {
      abortAlgorithm = (reason) =>
        webidl.invokeCallbackFunction(
          underlyingSinkDict.abort,
          [reason],
          underlyingSink,
          webidl.converters["Promise<undefined>"],
          {
            prefix:
              "Failed to call 'abortAlgorithm' on 'WritableStreamDefaultController'",
            returnsPromise: true,
          },
        );
    }
    setUpWritableStreamDefaultController(
      stream,
      controller,
      startAlgorithm,
      writeAlgorithm,
      closeAlgorithm,
      abortAlgorithm,
      highWaterMark,
      sizeAlgorithm,
    );
  }

  /**
   * @template W
   * @param {WritableStreamDefaultWriter<W>} writer
   * @param {WritableStream<W>} stream
   */
  function setUpWritableStreamDefaultWriter(writer, stream) {
    if (isWritableStreamLocked(stream) === true) {
      throw new TypeError("The stream is already locked.");
    }
    writer[_stream] = stream;
    stream[_writer] = writer;
    const state = stream[_state];
    if (state === "writable") {
      if (
        writableStreamCloseQueuedOrInFlight(stream) === false &&
        stream[_backpressure] === true
      ) {
        writer[_readyPromise] = new Deferred();
      } else {
        writer[_readyPromise] = new Deferred();
        writer[_readyPromise].resolve(undefined);
      }
      writer[_closedPromise] = new Deferred();
    } else if (state === "erroring") {
      writer[_readyPromise] = new Deferred();
      writer[_readyPromise].reject(stream[_storedError]);
      setPromiseIsHandledToTrue(writer[_readyPromise].promise);
      writer[_closedPromise] = new Deferred();
    } else if (state === "closed") {
      writer[_readyPromise] = new Deferred();
      writer[_readyPromise].resolve(undefined);
      writer[_closedPromise] = new Deferred();
      writer[_closedPromise].resolve(undefined);
    } else {
      assert(state === "errored");
      const storedError = stream[_storedError];
      writer[_readyPromise] = new Deferred();
      writer[_readyPromise].reject(storedError);
      setPromiseIsHandledToTrue(writer[_readyPromise].promise);
      writer[_closedPromise] = new Deferred();
      writer[_closedPromise].reject(storedError);
      setPromiseIsHandledToTrue(writer[_closedPromise].promise);
    }
  }

  /** @param {TransformStreamDefaultController} controller */
  function transformStreamDefaultControllerClearAlgorithms(controller) {
    controller[_transformAlgorithm] = undefined;
    controller[_flushAlgorithm] = undefined;
  }

  /**
   * @template O
   * @param {TransformStreamDefaultController<O>} controller
   * @param {O} chunk
   */
  function transformStreamDefaultControllerEnqueue(controller, chunk) {
    const stream = controller[_stream];
    const readableController = stream[_readable][_controller];
    if (
      readableStreamDefaultControllerCanCloseOrEnqueue(
        /** @type {ReadableStreamDefaultController<O>} */ readableController,
      ) === false
    ) {
      throw new TypeError("Readable stream is unavailable.");
    }
    try {
      readableStreamDefaultControllerEnqueue(
        /** @type {ReadableStreamDefaultController<O>} */ readableController,
        chunk,
      );
    } catch (e) {
      transformStreamErrorWritableAndUnblockWrite(stream, e);
      throw stream[_readable][_storedError];
    }
    const backpressure = readableStreamDefaultcontrollerHasBackpressure(
      /** @type {ReadableStreamDefaultController<O>} */ readableController,
    );
    if (backpressure !== stream[_backpressure]) {
      assert(backpressure === true);
      transformStreamSetBackpressure(stream, true);
    }
  }

  /**
   * @param {TransformStreamDefaultController} controller
   * @param {any=} e
   */
  function transformStreamDefaultControllerError(controller, e) {
    transformStreamError(controller[_stream], e);
  }

  /**
   * @template O
   * @param {TransformStreamDefaultController<O>} controller
   * @param {any} chunk
   * @returns {Promise<void>}
   */
  function transformStreamDefaultControllerPerformTransform(controller, chunk) {
    const transformPromise = controller[_transformAlgorithm](chunk, controller);
    return transformPromiseWith(transformPromise, undefined, (r) => {
      transformStreamError(controller[_stream], r);
      throw r;
    });
  }

  /** @param {TransformStreamDefaultController} controller */
  function transformStreamDefaultControllerTerminate(controller) {
    const stream = controller[_stream];
    const readableController = stream[_readable][_controller];
    readableStreamDefaultControllerClose(
      /** @type {ReadableStreamDefaultController} */ readableController,
    );
    const error = new TypeError("The stream has been terminated.");
    transformStreamErrorWritableAndUnblockWrite(stream, error);
  }

  /**
   * @param {TransformStream} stream
   * @param {any=} reason
   * @returns {Promise<void>}
   */
  function transformStreamDefaultSinkAbortAlgorithm(stream, reason) {
    transformStreamError(stream, reason);
    return resolvePromiseWith(undefined);
  }

  /**
   * @template I
   * @template O
   * @param {TransformStream<I, O>} stream
   * @returns {Promise<void>}
   */
  function transformStreamDefaultSinkCloseAlgorithm(stream) {
    const readable = stream[_readable];
    const controller = stream[_controller];
    const flushPromise = controller[_flushAlgorithm](controller);
    transformStreamDefaultControllerClearAlgorithms(controller);
    return transformPromiseWith(flushPromise, () => {
      if (readable[_state] === "errored") {
        throw readable[_storedError];
      }
      readableStreamDefaultControllerClose(
        /** @type {ReadableStreamDefaultController} */ readable[_controller],
      );
    }, (r) => {
      transformStreamError(stream, r);
      throw readable[_storedError];
    });
  }

  /**
   * @template I
   * @template O
   * @param {TransformStream<I, O>} stream
   * @param {I} chunk
   * @returns {Promise<void>}
   */
  function transformStreamDefaultSinkWriteAlgorithm(stream, chunk) {
    assert(stream[_writable][_state] === "writable");
    const controller = stream[_controller];
    if (stream[_backpressure] === true) {
      const backpressureChangePromise = stream[_backpressureChangePromise];
      assert(backpressureChangePromise !== undefined);
      return transformPromiseWith(backpressureChangePromise.promise, () => {
        const writable = stream[_writable];
        const state = writable[_state];
        if (state === "erroring") {
          throw writable[_storedError];
        }
        assert(state === "writable");
        return transformStreamDefaultControllerPerformTransform(
          controller,
          chunk,
        );
      });
    }
    return transformStreamDefaultControllerPerformTransform(controller, chunk);
  }

  /**
   * @param {TransformStream} stream
   * @returns {Promise<void>}
   */
  function transformStreamDefaultSourcePullAlgorithm(stream) {
    assert(stream[_backpressure] === true);
    assert(stream[_backpressureChangePromise] !== undefined);
    transformStreamSetBackpressure(stream, false);
    return stream[_backpressureChangePromise].promise;
  }

  /**
   * @param {TransformStream} stream
   * @param {any=} e
   */
  function transformStreamError(stream, e) {
    readableStreamDefaultControllerError(
      /** @type {ReadableStreamDefaultController} */ stream[_readable][
        _controller
      ],
      e,
    );
    transformStreamErrorWritableAndUnblockWrite(stream, e);
  }

  /**
   * @param {TransformStream} stream
   * @param {any=} e
   */
  function transformStreamErrorWritableAndUnblockWrite(stream, e) {
    transformStreamDefaultControllerClearAlgorithms(stream[_controller]);
    writableStreamDefaultControllerErrorIfNeeded(
      stream[_writable][_controller],
      e,
    );
    if (stream[_backpressure] === true) {
      transformStreamSetBackpressure(stream, false);
    }
  }

  /**
   * @param {TransformStream} stream
   * @param {boolean} backpressure
   */
  function transformStreamSetBackpressure(stream, backpressure) {
    assert(stream[_backpressure] !== backpressure);
    if (stream[_backpressureChangePromise] !== undefined) {
      stream[_backpressureChangePromise].resolve(undefined);
    }
    stream[_backpressureChangePromise] = new Deferred();
    stream[_backpressure] = backpressure;
  }

  /**
   * @param {WritableStream} stream
   * @param {any=} reason
   * @returns {Promise<void>}
   */
  function writableStreamAbort(stream, reason) {
    const state = stream[_state];
    if (state === "closed" || state === "errored") {
      return resolvePromiseWith(undefined);
    }
    stream[_controller][_signal][signalAbort](reason);
    if (state === "closed" || state === "errored") {
      return resolvePromiseWith(undefined);
    }
    if (stream[_pendingAbortRequest] !== undefined) {
      return stream[_pendingAbortRequest].deferred.promise;
    }
    assert(state === "writable" || state === "erroring");
    let wasAlreadyErroring = false;
    if (state === "erroring") {
      wasAlreadyErroring = true;
      reason = undefined;
    }
    /** Deferred<void> */
    const deferred = new Deferred();
    stream[_pendingAbortRequest] = {
      deferred,
      reason,
      wasAlreadyErroring,
    };
    if (wasAlreadyErroring === false) {
      writableStreamStartErroring(stream, reason);
    }
    return deferred.promise;
  }

  /**
   * @param {WritableStream} stream
   * @returns {Promise<void>}
   */
  function writableStreamAddWriteRequest(stream) {
    assert(isWritableStreamLocked(stream) === true);
    assert(stream[_state] === "writable");
    /** @type {Deferred<void>} */
    const deferred = new Deferred();
    ArrayPrototypePush(stream[_writeRequests], deferred);
    return deferred.promise;
  }

  /**
   * @param {WritableStream} stream
   * @returns {Promise<void>}
   */
  function writableStreamClose(stream) {
    const state = stream[_state];
    if (state === "closed" || state === "errored") {
      return PromiseReject(
        new TypeError("Writable stream is closed or errored."),
      );
    }
    assert(state === "writable" || state === "erroring");
    assert(writableStreamCloseQueuedOrInFlight(stream) === false);
    /** @type {Deferred<void>} */
    const deferred = new Deferred();
    stream[_closeRequest] = deferred;
    const writer = stream[_writer];
    if (
      writer !== undefined && stream[_backpressure] === true &&
      state === "writable"
    ) {
      writer[_readyPromise].resolve(undefined);
    }
    writableStreamDefaultControllerClose(stream[_controller]);
    return deferred.promise;
  }

  /**
   * @param {WritableStream} stream
   * @returns {boolean}
   */
  function writableStreamCloseQueuedOrInFlight(stream) {
    if (
      stream[_closeRequest] === undefined &&
      stream[_inFlightCloseRequest] === undefined
    ) {
      return false;
    }
    return true;
  }

  /**
   * @param {WritableStream} stream
   * @param {any=} error
   */
  function writableStreamDealWithRejection(stream, error) {
    const state = stream[_state];
    if (state === "writable") {
      writableStreamStartErroring(stream, error);
      return;
    }
    assert(state === "erroring");
    writableStreamFinishErroring(stream);
  }

  /**
   * @template W
   * @param {WritableStreamDefaultController<W>} controller
   */
  function writableStreamDefaultControllerAdvanceQueueIfNeeded(controller) {
    const stream = controller[_stream];
    if (controller[_started] === false) {
      return;
    }
    if (stream[_inFlightWriteRequest] !== undefined) {
      return;
    }
    const state = stream[_state];
    assert(state !== "closed" && state !== "errored");
    if (state === "erroring") {
      writableStreamFinishErroring(stream);
      return;
    }
    if (controller[_queue].length === 0) {
      return;
    }
    const value = peekQueueValue(controller);
    if (value === _close) {
      writableStreamDefaultControllerProcessClose(controller);
    } else {
      writableStreamDefaultControllerProcessWrite(controller, value);
    }
  }

  function writableStreamDefaultControllerClearAlgorithms(controller) {
    controller[_writeAlgorithm] = undefined;
    controller[_closeAlgorithm] = undefined;
    controller[_abortAlgorithm] = undefined;
    controller[_strategySizeAlgorithm] = undefined;
  }

  /** @param {WritableStreamDefaultController} controller */
  function writableStreamDefaultControllerClose(controller) {
    enqueueValueWithSize(controller, _close, 0);
    writableStreamDefaultControllerAdvanceQueueIfNeeded(controller);
  }

  /**
   * @param {WritableStreamDefaultController} controller
   * @param {any} error
   */
  function writableStreamDefaultControllerError(controller, error) {
    const stream = controller[_stream];
    assert(stream[_state] === "writable");
    writableStreamDefaultControllerClearAlgorithms(controller);
    writableStreamStartErroring(stream, error);
  }

  /**
   * @param {WritableStreamDefaultController} controller
   * @param {any} error
   */
  function writableStreamDefaultControllerErrorIfNeeded(controller, error) {
    if (controller[_stream][_state] === "writable") {
      writableStreamDefaultControllerError(controller, error);
    }
  }

  /**
   * @param {WritableStreamDefaultController} controller
   * @returns {boolean}
   */
  function writableStreamDefaultControllerGetBackpressure(controller) {
    const desiredSize = writableStreamDefaultControllerGetDesiredSize(
      controller,
    );
    return desiredSize <= 0;
  }

  /**
   * @template W
   * @param {WritableStreamDefaultController<W>} controller
   * @param {W} chunk
   * @returns {number}
   */
  function writableStreamDefaultControllerGetChunkSize(controller, chunk) {
    let value;
    try {
      value = controller[_strategySizeAlgorithm](chunk);
    } catch (e) {
      writableStreamDefaultControllerErrorIfNeeded(controller, e);
      return 1;
    }
    return value;
  }

  /**
   * @param {WritableStreamDefaultController} controller
   * @returns {number}
   */
  function writableStreamDefaultControllerGetDesiredSize(controller) {
    return controller[_strategyHWM] - controller[_queueTotalSize];
  }

  /** @param {WritableStreamDefaultController} controller */
  function writableStreamDefaultControllerProcessClose(controller) {
    const stream = controller[_stream];
    writableStreamMarkCloseRequestInFlight(stream);
    dequeueValue(controller);
    assert(controller[_queue].length === 0);
    const sinkClosePromise = controller[_closeAlgorithm]();
    writableStreamDefaultControllerClearAlgorithms(controller);
    uponPromise(sinkClosePromise, () => {
      writableStreamFinishInFlightClose(stream);
    }, (reason) => {
      writableStreamFinishInFlightCloseWithError(stream, reason);
    });
  }

  /**
   * @template W
   * @param {WritableStreamDefaultController<W>} controller
   * @param {W} chunk
   */
  function writableStreamDefaultControllerProcessWrite(controller, chunk) {
    const stream = controller[_stream];
    writableStreamMarkFirstWriteRequestInFlight(stream);
    const sinkWritePromise = controller[_writeAlgorithm](chunk, controller);
    uponPromise(sinkWritePromise, () => {
      writableStreamFinishInFlightWrite(stream);
      const state = stream[_state];
      assert(state === "writable" || state === "erroring");
      dequeueValue(controller);
      if (
        writableStreamCloseQueuedOrInFlight(stream) === false &&
        state === "writable"
      ) {
        const backpressure = writableStreamDefaultControllerGetBackpressure(
          controller,
        );
        writableStreamUpdateBackpressure(stream, backpressure);
      }
      writableStreamDefaultControllerAdvanceQueueIfNeeded(controller);
    }, (reason) => {
      if (stream[_state] === "writable") {
        writableStreamDefaultControllerClearAlgorithms(controller);
      }
      writableStreamFinishInFlightWriteWithError(stream, reason);
    });
  }

  /**
   * @template W
   * @param {WritableStreamDefaultController<W>} controller
   * @param {W} chunk
   * @param {number} chunkSize
   */
  function writableStreamDefaultControllerWrite(controller, chunk, chunkSize) {
    try {
      enqueueValueWithSize(controller, chunk, chunkSize);
    } catch (e) {
      writableStreamDefaultControllerErrorIfNeeded(controller, e);
      return;
    }
    const stream = controller[_stream];
    if (
      writableStreamCloseQueuedOrInFlight(stream) === false &&
      stream[_state] === "writable"
    ) {
      const backpressure = writableStreamDefaultControllerGetBackpressure(
        controller,
      );
      writableStreamUpdateBackpressure(stream, backpressure);
    }
    writableStreamDefaultControllerAdvanceQueueIfNeeded(controller);
  }

  /**
   * @param {WritableStreamDefaultWriter} writer
   * @param {any=} reason
   * @returns {Promise<void>}
   */
  function writableStreamDefaultWriterAbort(writer, reason) {
    const stream = writer[_stream];
    assert(stream !== undefined);
    return writableStreamAbort(stream, reason);
  }

  /**
   * @param {WritableStreamDefaultWriter} writer
   * @returns {Promise<void>}
   */
  function writableStreamDefaultWriterClose(writer) {
    const stream = writer[_stream];
    assert(stream !== undefined);
    return writableStreamClose(stream);
  }

  /**
   * @param {WritableStreamDefaultWriter} writer
   * @returns {Promise<void>}
   */
  function writableStreamDefaultWriterCloseWithErrorPropagation(writer) {
    const stream = writer[_stream];
    assert(stream !== undefined);
    const state = stream[_state];
    if (
      writableStreamCloseQueuedOrInFlight(stream) === true || state === "closed"
    ) {
      return resolvePromiseWith(undefined);
    }
    if (state === "errored") {
      return PromiseReject(stream[_storedError]);
    }
    assert(state === "writable" || state === "erroring");
    return writableStreamDefaultWriterClose(writer);
  }

  /**
   * @param {WritableStreamDefaultWriter} writer
   * @param {any=} error
   */
  function writableStreamDefaultWriterEnsureClosedPromiseRejected(
    writer,
    error,
  ) {
    if (writer[_closedPromise].state === "pending") {
      writer[_closedPromise].reject(error);
    } else {
      writer[_closedPromise] = new Deferred();
      writer[_closedPromise].reject(error);
    }
    setPromiseIsHandledToTrue(writer[_closedPromise].promise);
  }

  /**
   * @param {WritableStreamDefaultWriter} writer
   * @param {any=} error
   */
  function writableStreamDefaultWriterEnsureReadyPromiseRejected(
    writer,
    error,
  ) {
    if (writer[_readyPromise].state === "pending") {
      writer[_readyPromise].reject(error);
    } else {
      writer[_readyPromise] = new Deferred();
      writer[_readyPromise].reject(error);
    }
    setPromiseIsHandledToTrue(writer[_readyPromise].promise);
  }

  /**
   * @param {WritableStreamDefaultWriter} writer
   * @returns {number | null}
   */
  function writableStreamDefaultWriterGetDesiredSize(writer) {
    const stream = writer[_stream];
    const state = stream[_state];
    if (state === "errored" || state === "erroring") {
      return null;
    }
    if (state === "closed") {
      return 0;
    }
    return writableStreamDefaultControllerGetDesiredSize(stream[_controller]);
  }

  /** @param {WritableStreamDefaultWriter} writer */
  function writableStreamDefaultWriterRelease(writer) {
    const stream = writer[_stream];
    assert(stream !== undefined);
    assert(stream[_writer] === writer);
    const releasedError = new TypeError(
      "The writer has already been released.",
    );
    writableStreamDefaultWriterEnsureReadyPromiseRejected(
      writer,
      releasedError,
    );
    writableStreamDefaultWriterEnsureClosedPromiseRejected(
      writer,
      releasedError,
    );
    stream[_writer] = undefined;
    writer[_stream] = undefined;
  }

  /**
   * @template W
   * @param {WritableStreamDefaultWriter<W>} writer
   * @param {W} chunk
   * @returns {Promise<void>}
   */
  function writableStreamDefaultWriterWrite(writer, chunk) {
    const stream = writer[_stream];
    assert(stream !== undefined);
    const controller = stream[_controller];
    const chunkSize = writableStreamDefaultControllerGetChunkSize(
      controller,
      chunk,
    );
    if (stream !== writer[_stream]) {
      return PromiseReject(new TypeError("Writer's stream is unexpected."));
    }
    const state = stream[_state];
    if (state === "errored") {
      return PromiseReject(stream[_storedError]);
    }
    if (
      writableStreamCloseQueuedOrInFlight(stream) === true || state === "closed"
    ) {
      return PromiseReject(
        new TypeError("The stream is closing or is closed."),
      );
    }
    if (state === "erroring") {
      return PromiseReject(stream[_storedError]);
    }
    assert(state === "writable");
    const promise = writableStreamAddWriteRequest(stream);
    writableStreamDefaultControllerWrite(controller, chunk, chunkSize);
    return promise;
  }

  /** @param {WritableStream} stream */
  function writableStreamFinishErroring(stream) {
    assert(stream[_state] === "erroring");
    assert(writableStreamHasOperationMarkedInFlight(stream) === false);
    stream[_state] = "errored";
    stream[_controller][_errorSteps]();
    const storedError = stream[_storedError];
    for (const writeRequest of stream[_writeRequests]) {
      writeRequest.reject(storedError);
    }
    stream[_writeRequests] = [];
    if (stream[_pendingAbortRequest] === undefined) {
      writableStreamRejectCloseAndClosedPromiseIfNeeded(stream);
      return;
    }
    const abortRequest = stream[_pendingAbortRequest];
    stream[_pendingAbortRequest] = undefined;
    if (abortRequest.wasAlreadyErroring === true) {
      abortRequest.deferred.reject(storedError);
      writableStreamRejectCloseAndClosedPromiseIfNeeded(stream);
      return;
    }
    const promise = stream[_controller][_abortSteps](abortRequest.reason);
    uponPromise(promise, () => {
      abortRequest.deferred.resolve(undefined);
      writableStreamRejectCloseAndClosedPromiseIfNeeded(stream);
    }, (reason) => {
      abortRequest.deferred.reject(reason);
      writableStreamRejectCloseAndClosedPromiseIfNeeded(stream);
    });
  }

  /** @param {WritableStream} stream */
  function writableStreamFinishInFlightClose(stream) {
    assert(stream[_inFlightCloseRequest] !== undefined);
    stream[_inFlightCloseRequest].resolve(undefined);
    stream[_inFlightCloseRequest] = undefined;
    const state = stream[_state];
    assert(state === "writable" || state === "erroring");
    if (state === "erroring") {
      stream[_storedError] = undefined;
      if (stream[_pendingAbortRequest] !== undefined) {
        stream[_pendingAbortRequest].deferred.resolve(undefined);
        stream[_pendingAbortRequest] = undefined;
      }
    }
    stream[_state] = "closed";
    const writer = stream[_writer];
    if (writer !== undefined) {
      writer[_closedPromise].resolve(undefined);
    }
    assert(stream[_pendingAbortRequest] === undefined);
    assert(stream[_storedError] === undefined);
  }

  /**
   * @param {WritableStream} stream
   * @param {any=} error
   */
  function writableStreamFinishInFlightCloseWithError(stream, error) {
    assert(stream[_inFlightCloseRequest] !== undefined);
    stream[_inFlightCloseRequest].reject(error);
    stream[_inFlightCloseRequest] = undefined;
    assert(stream[_state] === "writable" || stream[_state] === "erroring");
    if (stream[_pendingAbortRequest] !== undefined) {
      stream[_pendingAbortRequest].deferred.reject(error);
      stream[_pendingAbortRequest] = undefined;
    }
    writableStreamDealWithRejection(stream, error);
  }

  /** @param {WritableStream} stream */
  function writableStreamFinishInFlightWrite(stream) {
    assert(stream[_inFlightWriteRequest] !== undefined);
    stream[_inFlightWriteRequest].resolve(undefined);
    stream[_inFlightWriteRequest] = undefined;
  }

  /**
   * @param {WritableStream} stream
   * @param {any=} error
   */
  function writableStreamFinishInFlightWriteWithError(stream, error) {
    assert(stream[_inFlightWriteRequest] !== undefined);
    stream[_inFlightWriteRequest].reject(error);
    stream[_inFlightWriteRequest] = undefined;
    assert(stream[_state] === "writable" || stream[_state] === "erroring");
    writableStreamDealWithRejection(stream, error);
  }

  /**
   * @param {WritableStream} stream
   * @returns {boolean}
   */
  function writableStreamHasOperationMarkedInFlight(stream) {
    if (
      stream[_inFlightWriteRequest] === undefined &&
      stream[_inFlightCloseRequest] === undefined
    ) {
      return false;
    }
    return true;
  }

  /** @param {WritableStream} stream */
  function writableStreamMarkCloseRequestInFlight(stream) {
    assert(stream[_inFlightCloseRequest] === undefined);
    assert(stream[_closeRequest] !== undefined);
    stream[_inFlightCloseRequest] = stream[_closeRequest];
    stream[_closeRequest] = undefined;
  }

  /**
   * @template W
   * @param {WritableStream<W>} stream
   */
  function writableStreamMarkFirstWriteRequestInFlight(stream) {
    assert(stream[_inFlightWriteRequest] === undefined);
    assert(stream[_writeRequests].length);
    const writeRequest = stream[_writeRequests].shift();
    stream[_inFlightWriteRequest] = writeRequest;
  }

  /** @param {WritableStream} stream */
  function writableStreamRejectCloseAndClosedPromiseIfNeeded(stream) {
    assert(stream[_state] === "errored");
    if (stream[_closeRequest] !== undefined) {
      assert(stream[_inFlightCloseRequest] === undefined);
      stream[_closeRequest].reject(stream[_storedError]);
      stream[_closeRequest] = undefined;
    }
    const writer = stream[_writer];
    if (writer !== undefined) {
      writer[_closedPromise].reject(stream[_storedError]);
      setPromiseIsHandledToTrue(writer[_closedPromise].promise);
    }
  }

  /**
   * @param {WritableStream} stream
   * @param {any=} reason
   */
  function writableStreamStartErroring(stream, reason) {
    assert(stream[_storedError] === undefined);
    assert(stream[_state] === "writable");
    const controller = stream[_controller];
    assert(controller !== undefined);
    stream[_state] = "erroring";
    stream[_storedError] = reason;
    const writer = stream[_writer];
    if (writer !== undefined) {
      writableStreamDefaultWriterEnsureReadyPromiseRejected(writer, reason);
    }
    if (
      writableStreamHasOperationMarkedInFlight(stream) === false &&
      controller[_started] === true
    ) {
      writableStreamFinishErroring(stream);
    }
  }

  /**
   * @param {WritableStream} stream
   * @param {boolean} backpressure
   */
  function writableStreamUpdateBackpressure(stream, backpressure) {
    assert(stream[_state] === "writable");
    assert(writableStreamCloseQueuedOrInFlight(stream) === false);
    const writer = stream[_writer];
    if (writer !== undefined && backpressure !== stream[_backpressure]) {
      if (backpressure === true) {
        writer[_readyPromise] = new Deferred();
      } else {
        assert(backpressure === false);
        writer[_readyPromise].resolve(undefined);
      }
    }
    stream[_backpressure] = backpressure;
  }

  /**
   * @template T
   * @param {T} value
   * @param {boolean} done
   * @returns {IteratorResult<T>}
   */
  function createIteratorResult(value, done) {
    const result = ObjectCreate(null);
    ObjectDefineProperties(result, {
      value: { value, writable: true, enumerable: true, configurable: true },
      done: {
        value: done,
        writable: true,
        enumerable: true,
        configurable: true,
      },
    });
    return result;
  }

  /** @type {AsyncIterator<unknown, unknown>} */
  const asyncIteratorPrototype = ObjectGetPrototypeOf(
    ObjectGetPrototypeOf(async function* () {}).prototype,
  );

  /** @type {AsyncIterator<unknown>} */
  const readableStreamAsyncIteratorPrototype = ObjectSetPrototypeOf({
    /** @returns {Promise<IteratorResult<unknown>>} */
    next() {
      /** @type {ReadableStreamDefaultReader} */
      const reader = this[_reader];
      if (reader[_stream] === undefined) {
        return PromiseReject(
          new TypeError(
            "Cannot get the next iteration result once the reader has been released.",
          ),
        );
      }
      /** @type {Deferred<IteratorResult<any>>} */
      const promise = new Deferred();
      /** @type {ReadRequest} */
      const readRequest = {
        chunkSteps(chunk) {
          promise.resolve(createIteratorResult(chunk, false));
        },
        closeSteps() {
          readableStreamDefaultReaderRelease(reader);
          promise.resolve(createIteratorResult(undefined, true));
        },
        errorSteps(e) {
          readableStreamDefaultReaderRelease(reader);
          promise.reject(e);
        },
      };
      readableStreamDefaultReaderRead(reader, readRequest);
      return promise.promise;
    },
    /**
     * @param {unknown} arg
     * @returns {Promise<IteratorResult<unknown>>}
     */
    async return(arg) {
      /** @type {ReadableStreamDefaultReader} */
      const reader = this[_reader];
      if (reader[_stream] === undefined) {
        return createIteratorResult(undefined, true);
      }
      assert(reader[_readRequests].length === 0);
      if (this[_preventCancel] === false) {
        const result = readableStreamReaderGenericCancel(reader, arg);
        readableStreamDefaultReaderRelease(reader);
        await result;
        return createIteratorResult(arg, true);
      }
      readableStreamDefaultReaderRelease(reader);
      return createIteratorResult(undefined, true);
    },
  }, asyncIteratorPrototype);

  class ByteLengthQueuingStrategy {
    /** @param {{ highWaterMark: number }} init */
    constructor(init) {
      const prefix = "Failed to construct 'ByteLengthQueuingStrategy'";
      webidl.requiredArguments(arguments.length, 1, { prefix });
      init = webidl.converters.QueuingStrategyInit(init, {
        prefix,
        context: "Argument 1",
      });
      this[webidl.brand] = webidl.brand;
      this[_globalObject] = window;
      this[_highWaterMark] = init.highWaterMark;
    }

    /** @returns {number} */
    get highWaterMark() {
      webidl.assertBranded(this, ByteLengthQueuingStrategyPrototype);
      return this[_highWaterMark];
    }

    /** @returns {(chunk: ArrayBufferView) => number} */
    get size() {
      webidl.assertBranded(this, ByteLengthQueuingStrategyPrototype);
      initializeByteLengthSizeFunction(this[_globalObject]);
      return WeakMapPrototypeGet(byteSizeFunctionWeakMap, this[_globalObject]);
    }

    [SymbolFor("Deno.customInspect")](inspect) {
      return inspect(consoleInternal.createFilteredInspectProxy({
        object: this,
        evaluate: ObjectPrototypeIsPrototypeOf(
          ByteLengthQueuingStrategyPrototype,
          this,
        ),
        keys: [
          "highWaterMark",
          "size",
        ],
      }));
    }
  }

  webidl.configurePrototype(ByteLengthQueuingStrategy);
  const ByteLengthQueuingStrategyPrototype =
    ByteLengthQueuingStrategy.prototype;

  /** @type {WeakMap<typeof globalThis, (chunk: ArrayBufferView) => number>} */
  const byteSizeFunctionWeakMap = new WeakMap();

  function initializeByteLengthSizeFunction(globalObject) {
    if (WeakMapPrototypeHas(byteSizeFunctionWeakMap, globalObject)) {
      return;
    }
    const size = (chunk) => chunk.byteLength;
    WeakMapPrototypeSet(byteSizeFunctionWeakMap, globalObject, size);
  }

  class CountQueuingStrategy {
    /** @param {{ highWaterMark: number }} init */
    constructor(init) {
      const prefix = "Failed to construct 'CountQueuingStrategy'";
      webidl.requiredArguments(arguments.length, 1, { prefix });
      init = webidl.converters.QueuingStrategyInit(init, {
        prefix,
        context: "Argument 1",
      });
      this[webidl.brand] = webidl.brand;
      this[_globalObject] = window;
      this[_highWaterMark] = init.highWaterMark;
    }

    /** @returns {number} */
    get highWaterMark() {
      webidl.assertBranded(this, CountQueuingStrategyPrototype);
      return this[_highWaterMark];
    }

    /** @returns {(chunk: any) => 1} */
    get size() {
      webidl.assertBranded(this, CountQueuingStrategyPrototype);
      initializeCountSizeFunction(this[_globalObject]);
      return WeakMapPrototypeGet(countSizeFunctionWeakMap, this[_globalObject]);
    }

    [SymbolFor("Deno.customInspect")](inspect) {
      return inspect(consoleInternal.createFilteredInspectProxy({
        object: this,
        evaluate: ObjectPrototypeIsPrototypeOf(
          CountQueuingStrategyPrototype,
          this,
        ),
        keys: [
          "highWaterMark",
          "size",
        ],
      }));
    }
  }

  webidl.configurePrototype(CountQueuingStrategy);
  const CountQueuingStrategyPrototype = CountQueuingStrategy.prototype;

  /** @type {WeakMap<typeof globalThis, () => 1>} */
  const countSizeFunctionWeakMap = new WeakMap();

  /** @param {typeof globalThis} globalObject */
  function initializeCountSizeFunction(globalObject) {
    if (WeakMapPrototypeHas(countSizeFunctionWeakMap, globalObject)) {
      return;
    }
    const size = () => 1;
    WeakMapPrototypeSet(countSizeFunctionWeakMap, globalObject, size);
  }

  const _maybeRid = Symbol("[[maybeRid]]");
  /** @template R */
  class ReadableStream {
    /** @type {ReadableStreamDefaultController | ReadableByteStreamController} */
    [_controller];
    /** @type {boolean} */
    [_detached];
    /** @type {boolean} */
    [_disturbed];
    /** @type {ReadableStreamDefaultReader | ReadableStreamBYOBReader} */
    [_reader];
    /** @type {"readable" | "closed" | "errored"} */
    [_state];
    /** @type {any} */
    [_storedError];
    /** @type {number | null} */
    [_maybeRid] = null;

    /**
     * @param {UnderlyingSource<R>=} underlyingSource
     * @param {QueuingStrategy<R>=} strategy
     */
    constructor(underlyingSource = undefined, strategy = {}) {
      const prefix = "Failed to construct 'ReadableStream'";
      if (underlyingSource !== undefined) {
        underlyingSource = webidl.converters.object(underlyingSource, {
          prefix,
          context: "Argument 1",
        });
      }
      strategy = webidl.converters.QueuingStrategy(strategy, {
        prefix,
        context: "Argument 2",
      });
      this[webidl.brand] = webidl.brand;
      if (underlyingSource === undefined) {
        underlyingSource = null;
      }
      const underlyingSourceDict = webidl.converters.UnderlyingSource(
        underlyingSource,
        { prefix, context: "underlyingSource" },
      );
      initializeReadableStream(this);
      if (underlyingSourceDict.type === "bytes") {
        if (strategy.size !== undefined) {
          throw new RangeError(
            `${prefix}: When underlying source is "bytes", strategy.size must be undefined.`,
          );
        }
        const highWaterMark = extractHighWaterMark(strategy, 0);
        setUpReadableByteStreamControllerFromUnderlyingSource(
          // @ts-ignore cannot easily assert this is ReadableStream<ArrayBuffer>
          this,
          underlyingSource,
          underlyingSourceDict,
          highWaterMark,
        );
      } else {
        assert(!(ReflectHas(underlyingSourceDict, "type")));
        const sizeAlgorithm = extractSizeAlgorithm(strategy);
        const highWaterMark = extractHighWaterMark(strategy, 1);
        setUpReadableStreamDefaultControllerFromUnderlyingSource(
          this,
          underlyingSource,
          underlyingSourceDict,
          highWaterMark,
          sizeAlgorithm,
        );
      }
    }

    /** @returns {boolean} */
    get locked() {
      webidl.assertBranded(this, ReadableStreamPrototype);
      return isReadableStreamLocked(this);
    }

    /**
     * @param {any=} reason
     * @returns {Promise<void>}
     */
    cancel(reason = undefined) {
      try {
        webidl.assertBranded(this, ReadableStreamPrototype);
        if (reason !== undefined) {
          reason = webidl.converters.any(reason);
        }
      } catch (err) {
        return PromiseReject(err);
      }
      if (isReadableStreamLocked(this)) {
        return PromiseReject(
          new TypeError("Cannot cancel a locked ReadableStream."),
        );
      }
      return readableStreamCancel(this, reason);
    }

    /**
     * @param {ReadableStreamGetReaderOptions=} options
     * @returns {ReadableStreamDefaultReader<R> | ReadableStreamBYOBReader}
     */
    getReader(options = {}) {
      webidl.assertBranded(this, ReadableStreamPrototype);
      const prefix = "Failed to execute 'getReader' on 'ReadableStream'";
      options = webidl.converters.ReadableStreamGetReaderOptions(options, {
        prefix,
        context: "Argument 1",
      });
      if (options.mode === undefined) {
        return acquireReadableStreamDefaultReader(this);
      } else {
        assert(options.mode === "byob");
        return acquireReadableStreamBYOBReader(this);
      }
    }

    /**
     * @template T
     * @param {{ readable: ReadableStream<T>, writable: WritableStream<R> }} transform
     * @param {PipeOptions=} options
     * @returns {ReadableStream<T>}
     */
    pipeThrough(transform, options = {}) {
      webidl.assertBranded(this, ReadableStreamPrototype);
      const prefix = "Failed to execute 'pipeThrough' on 'ReadableStream'";
      webidl.requiredArguments(arguments.length, 1, { prefix });
      transform = webidl.converters.ReadableWritablePair(transform, {
        prefix,
        context: "Argument 1",
      });
      options = webidl.converters.StreamPipeOptions(options, {
        prefix,
        context: "Argument 2",
      });
      const { readable, writable } = transform;
      const { preventClose, preventAbort, preventCancel, signal } = options;
      if (isReadableStreamLocked(this)) {
        throw new TypeError("ReadableStream is already locked.");
      }
      if (isWritableStreamLocked(writable)) {
        throw new TypeError("Target WritableStream is already locked.");
      }
      const promise = readableStreamPipeTo(
        this,
        writable,
        preventClose,
        preventAbort,
        preventCancel,
        signal,
      );
      setPromiseIsHandledToTrue(promise);
      return readable;
    }

    /**
     * @param {WritableStream<R>} destination
     * @param {PipeOptions=} options
     * @returns {Promise<void>}
     */
    pipeTo(destination, options = {}) {
      try {
        webidl.assertBranded(this, ReadableStreamPrototype);
        const prefix = "Failed to execute 'pipeTo' on 'ReadableStream'";
        webidl.requiredArguments(arguments.length, 1, { prefix });
        destination = webidl.converters.WritableStream(destination, {
          prefix,
          context: "Argument 1",
        });
        options = webidl.converters.StreamPipeOptions(options, {
          prefix,
          context: "Argument 2",
        });
      } catch (err) {
        return PromiseReject(err);
      }
      const { preventClose, preventAbort, preventCancel, signal } = options;
      if (isReadableStreamLocked(this)) {
        return PromiseReject(
          new TypeError("ReadableStream is already locked."),
        );
      }
      if (isWritableStreamLocked(destination)) {
        return PromiseReject(
          new TypeError("destination WritableStream is already locked."),
        );
      }
      return readableStreamPipeTo(
        this,
        destination,
        preventClose,
        preventAbort,
        preventCancel,
        signal,
      );
    }

    /** @returns {[ReadableStream<R>, ReadableStream<R>]} */
    tee() {
      webidl.assertBranded(this, ReadableStreamPrototype);
      return readableStreamTee(this, false);
    }

    // TODO(lucacasonato): should be moved to webidl crate
    /**
     * @param {ReadableStreamIteratorOptions=} options
     * @returns {AsyncIterableIterator<R>}
     */
    values(options = {}) {
      webidl.assertBranded(this, ReadableStreamPrototype);
      const prefix = "Failed to execute 'values' on 'ReadableStream'";
      options = webidl.converters.ReadableStreamIteratorOptions(options, {
        prefix,
        context: "Argument 1",
      });
      /** @type {AsyncIterableIterator<R>} */
      const iterator = ObjectCreate(readableStreamAsyncIteratorPrototype);
      const reader = acquireReadableStreamDefaultReader(this);
      iterator[_reader] = reader;
      iterator[_preventCancel] = options.preventCancel;
      return iterator;
    }

    [SymbolFor("Deno.privateCustomInspect")](inspect) {
      return `${this.constructor.name} ${inspect({ locked: this.locked })}`;
    }
  }

  // TODO(lucacasonato): should be moved to webidl crate
  ReadableStream.prototype[SymbolAsyncIterator] =
    ReadableStream.prototype.values;
  ObjectDefineProperty(ReadableStream.prototype, SymbolAsyncIterator, {
    writable: true,
    enumerable: false,
    configurable: true,
  });

  webidl.configurePrototype(ReadableStream);
  const ReadableStreamPrototype = ReadableStream.prototype;

  function errorReadableStream(stream, e) {
    readableStreamDefaultControllerError(stream[_controller], e);
  }

  /** @template R */
  class ReadableStreamDefaultReader {
    /** @type {Deferred<void>} */
    [_closedPromise];
    /** @type {ReadableStream<R> | undefined} */
    [_stream];
    /** @type {ReadRequest[]} */
    [_readRequests];

    /** @param {ReadableStream<R>} stream */
    constructor(stream) {
      const prefix = "Failed to construct 'ReadableStreamDefaultReader'";
      webidl.requiredArguments(arguments.length, 1, { prefix });
      stream = webidl.converters.ReadableStream(stream, {
        prefix,
        context: "Argument 1",
      });
      this[webidl.brand] = webidl.brand;
      setUpReadableStreamDefaultReader(this, stream);
    }

    /** @returns {Promise<ReadableStreamReadResult<R>>} */
    read() {
      try {
        webidl.assertBranded(this, ReadableStreamDefaultReaderPrototype);
      } catch (err) {
        return PromiseReject(err);
      }
      if (this[_stream] === undefined) {
        return PromiseReject(
          new TypeError("Reader has no associated stream."),
        );
      }
      /** @type {Deferred<ReadableStreamReadResult<R>>} */
      const promise = new Deferred();
      /** @type {ReadRequest<R>} */
      const readRequest = {
        chunkSteps(chunk) {
          promise.resolve({ value: chunk, done: false });
        },
        closeSteps() {
          promise.resolve({ value: undefined, done: true });
        },
        errorSteps(e) {
          promise.reject(e);
        },
      };
      readableStreamDefaultReaderRead(this, readRequest);
      return promise.promise;
    }

    /** @returns {void} */
    releaseLock() {
      webidl.assertBranded(this, ReadableStreamDefaultReaderPrototype);
      if (this[_stream] === undefined) {
        return;
      }
      readableStreamDefaultReaderRelease(this);
    }

    get closed() {
      try {
        webidl.assertBranded(this, ReadableStreamDefaultReaderPrototype);
      } catch (err) {
        return PromiseReject(err);
      }
      return this[_closedPromise].promise;
    }

    /**
     * @param {any} reason
     * @returns {Promise<void>}
     */
    cancel(reason = undefined) {
      try {
        webidl.assertBranded(this, ReadableStreamDefaultReaderPrototype);
        if (reason !== undefined) {
          reason = webidl.converters.any(reason);
        }
      } catch (err) {
        return PromiseReject(err);
      }

      if (this[_stream] === undefined) {
        return PromiseReject(
          new TypeError("Reader has no associated stream."),
        );
      }
      return readableStreamReaderGenericCancel(this, reason);
    }

    [SymbolFor("Deno.privateCustomInspect")](inspect) {
      return `${this.constructor.name} ${inspect({ closed: this.closed })}`;
    }
  }

  webidl.configurePrototype(ReadableStreamDefaultReader);
  const ReadableStreamDefaultReaderPrototype =
    ReadableStreamDefaultReader.prototype;

  /** @template R */
  class ReadableStreamBYOBReader {
    /** @type {Deferred<void>} */
    [_closedPromise];
    /** @type {ReadableStream<R> | undefined} */
    [_stream];
    /** @type {ReadIntoRequest[]} */
    [_readIntoRequests];

    /** @param {ReadableStream<R>} stream */
    constructor(stream) {
      const prefix = "Failed to construct 'ReadableStreamBYOBReader'";
      webidl.requiredArguments(arguments.length, 1, { prefix });
      stream = webidl.converters.ReadableStream(stream, {
        prefix,
        context: "Argument 1",
      });
      this[webidl.brand] = webidl.brand;
      setUpReadableStreamBYOBReader(this, stream);
    }

    /**
     * @param {ArrayBufferView} view
     *  @returns {Promise<ReadableStreamBYOBReadResult>}
     */
    read(view) {
      try {
        webidl.assertBranded(this, ReadableStreamBYOBReaderPrototype);
        const prefix = "Failed to execute 'read' on 'ReadableStreamBYOBReader'";
        view = webidl.converters.ArrayBufferView(view, {
          prefix,
          context: "Argument 1",
        });
      } catch (err) {
        return PromiseReject(err);
      }

      if (view.byteLength === 0) {
        return PromiseReject(
          new TypeError("view must have non-zero byteLength"),
        );
      }
      if (view.buffer.byteLength === 0) {
        return PromiseReject(
          new TypeError("view's buffer must have non-zero byteLength"),
        );
      }
      if (isDetachedBuffer(view.buffer)) {
        return PromiseReject(
          new TypeError("view's buffer has been detached"),
        );
      }
      if (this[_stream] === undefined) {
        return PromiseReject(
          new TypeError("Reader has no associated stream."),
        );
      }
      /** @type {Deferred<ReadableStreamBYOBReadResult>} */
      const promise = new Deferred();
      /** @type {ReadIntoRequest} */
      const readIntoRequest = {
        chunkSteps(chunk) {
          promise.resolve({ value: chunk, done: false });
        },
        closeSteps(chunk) {
          promise.resolve({ value: chunk, done: true });
        },
        errorSteps(e) {
          promise.reject(e);
        },
      };
      readableStreamBYOBReaderRead(this, view, readIntoRequest);
      return promise.promise;
    }

    /** @returns {void} */
    releaseLock() {
      webidl.assertBranded(this, ReadableStreamBYOBReaderPrototype);
      if (this[_stream] === undefined) {
        return;
      }
      readableStreamBYOBReaderRelease(this);
    }

    get closed() {
      try {
        webidl.assertBranded(this, ReadableStreamBYOBReaderPrototype);
      } catch (err) {
        return PromiseReject(err);
      }
      return this[_closedPromise].promise;
    }

    /**
     * @param {any} reason
     * @returns {Promise<void>}
     */
    cancel(reason = undefined) {
      try {
        webidl.assertBranded(this, ReadableStreamBYOBReaderPrototype);
        if (reason !== undefined) {
          reason = webidl.converters.any(reason);
        }
      } catch (err) {
        return PromiseReject(err);
      }

      if (this[_stream] === undefined) {
        return PromiseReject(
          new TypeError("Reader has no associated stream."),
        );
      }
      return readableStreamReaderGenericCancel(this, reason);
    }

    [SymbolFor("Deno.privateCustomInspect")](inspect) {
      return `${this.constructor.name} ${inspect({ closed: this.closed })}`;
    }
  }

  webidl.configurePrototype(ReadableStreamBYOBReader);
  const ReadableStreamBYOBReaderPrototype = ReadableStreamBYOBReader.prototype;

  class ReadableStreamBYOBRequest {
    /** @type {ReadableByteStreamController} */
    [_controller];
    /** @type {ArrayBufferView | null} */
    [_view];

    /** @returns {ArrayBufferView | null} */
    get view() {
      webidl.assertBranded(this, ReadableStreamBYOBRequestPrototype);
      return this[_view];
    }

    constructor() {
      webidl.illegalConstructor();
    }

    respond(bytesWritten) {
      webidl.assertBranded(this, ReadableStreamBYOBRequestPrototype);
      const prefix =
        "Failed to execute 'respond' on 'ReadableStreamBYOBRequest'";
      webidl.requiredArguments(arguments.length, 1, { prefix });
      bytesWritten = webidl.converters["unsigned long long"](bytesWritten, {
        enforceRange: true,
        prefix,
        context: "Argument 1",
      });

      if (this[_controller] === undefined) {
        throw new TypeError("This BYOB request has been invalidated");
      }
      if (isDetachedBuffer(this[_view].buffer)) {
        throw new TypeError(
          "The BYOB request's buffer has been detached and so cannot be used as a response",
        );
      }
      assert(this[_view].byteLength > 0);
      assert(this[_view].buffer.byteLength > 0);
      readableByteStreamControllerRespond(this[_controller], bytesWritten);
    }

    respondWithNewView(view) {
      webidl.assertBranded(this, ReadableStreamBYOBRequestPrototype);
      const prefix =
        "Failed to execute 'respondWithNewView' on 'ReadableStreamBYOBRequest'";
      webidl.requiredArguments(arguments.length, 1, { prefix });
      view = webidl.converters.ArrayBufferView(view, {
        prefix,
        context: "Argument 1",
      });

      if (this[_controller] === undefined) {
        throw new TypeError("This BYOB request has been invalidated");
      }
      if (isDetachedBuffer(view.buffer)) {
        throw new TypeError(
          "The given view's buffer has been detached and so cannot be used as a response",
        );
      }
      readableByteStreamControllerRespondWithNewView(this[_controller], view);
    }
  }

  webidl.configurePrototype(ReadableStreamBYOBRequest);
  const ReadableStreamBYOBRequestPrototype =
    ReadableStreamBYOBRequest.prototype;

  class ReadableByteStreamController {
    /** @type {number | undefined} */
    [_autoAllocateChunkSize];
    /** @type {ReadableStreamBYOBRequest | null} */
    [_byobRequest];
    /** @type {(reason: any) => Promise<void>} */
    [_cancelAlgorithm];
    /** @type {boolean} */
    [_closeRequested];
    /** @type {boolean} */
    [_pullAgain];
    /** @type {(controller: this) => Promise<void>} */
    [_pullAlgorithm];
    /** @type {boolean} */
    [_pulling];
    /** @type {PullIntoDescriptor[]} */
    [_pendingPullIntos];
    /** @type {ReadableByteStreamQueueEntry[]} */
    [_queue];
    /** @type {number} */
    [_queueTotalSize];
    /** @type {boolean} */
    [_started];
    /** @type {number} */
    [_strategyHWM];
    /** @type {ReadableStream<ArrayBuffer>} */
    [_stream];

    constructor() {
      webidl.illegalConstructor();
    }

    /** @returns {ReadableStreamBYOBRequest | null} */
    get byobRequest() {
      webidl.assertBranded(this, ReadableByteStreamControllerPrototype);
      return readableByteStreamControllerGetBYOBRequest(this);
    }

    /** @returns {number | null} */
    get desiredSize() {
      webidl.assertBranded(this, ReadableByteStreamControllerPrototype);
      return readableByteStreamControllerGetDesiredSize(this);
    }

    /** @returns {void} */
    close() {
      webidl.assertBranded(this, ReadableByteStreamControllerPrototype);
      if (this[_closeRequested] === true) {
        throw new TypeError("Closed already requested.");
      }
      if (this[_stream][_state] !== "readable") {
        throw new TypeError(
          "ReadableByteStreamController's stream is not in a readable state.",
        );
      }
      readableByteStreamControllerClose(this);
    }

    /**
     * @param {ArrayBufferView} chunk
     * @returns {void}
     */
    enqueue(chunk) {
      webidl.assertBranded(this, ReadableByteStreamControllerPrototype);
      const prefix =
        "Failed to execute 'enqueue' on 'ReadableByteStreamController'";
      webidl.requiredArguments(arguments.length, 1, { prefix });
      const arg1 = "Argument 1";
      chunk = webidl.converters.ArrayBufferView(chunk, {
        prefix,
        context: arg1,
      });
      if (chunk.byteLength === 0) {
        throw webidl.makeException(TypeError, "length must be non-zero", {
          prefix,
          context: arg1,
        });
      }
      if (chunk.buffer.byteLength === 0) {
        throw webidl.makeException(
          TypeError,
          "buffer length must be non-zero",
          { prefix, context: arg1 },
        );
      }
      if (this[_closeRequested] === true) {
        throw new TypeError(
          "Cannot enqueue chunk after a close has been requested.",
        );
      }
      if (this[_stream][_state] !== "readable") {
        throw new TypeError(
          "Cannot enqueue chunk when underlying stream is not readable.",
        );
      }
      return readableByteStreamControllerEnqueue(this, chunk);
    }

    /**
     * @param {any=} e
     * @returns {void}
     */
    error(e = undefined) {
      webidl.assertBranded(this, ReadableByteStreamControllerPrototype);
      if (e !== undefined) {
        e = webidl.converters.any(e);
      }
      readableByteStreamControllerError(this, e);
    }

    [SymbolFor("Deno.customInspect")](inspect) {
      return inspect(consoleInternal.createFilteredInspectProxy({
        object: this,
        evaluate: ObjectPrototypeIsPrototypeOf(
          ReadableByteStreamControllerPrototype,
          this,
        ),
        keys: ["desiredSize"],
      }));
    }

    /**
     * @param {any} reason
     * @returns {Promise<void>}
     */
    [_cancelSteps](reason) {
      readableByteStreamControllerClearPendingPullIntos(this);
      resetQueue(this);
      const result = this[_cancelAlgorithm](reason);
      readableByteStreamControllerClearAlgorithms(this);
      return result;
    }

    /**
     * @param {ReadRequest<ArrayBuffer>} readRequest
     * @returns {void}
     */
    [_pullSteps](readRequest) {
      /** @type {ReadableStream<ArrayBuffer>} */
      const stream = this[_stream];
      assert(readableStreamHasDefaultReader(stream));
      if (this[_queueTotalSize] > 0) {
        assert(readableStreamGetNumReadRequests(stream) === 0);
        readableByteStreamControllerFillReadRequestFromQueue(this, readRequest);
        return;
      }
      const autoAllocateChunkSize = this[_autoAllocateChunkSize];
      if (autoAllocateChunkSize !== undefined) {
        let buffer;
        try {
          buffer = new ArrayBuffer(autoAllocateChunkSize);
        } catch (e) {
          readRequest.errorSteps(e);
          return;
        }
        /** @type {PullIntoDescriptor} */
        const pullIntoDescriptor = {
          buffer,
          bufferByteLength: autoAllocateChunkSize,
          byteOffset: 0,
          byteLength: autoAllocateChunkSize,
          bytesFilled: 0,
          elementSize: 1,
          viewConstructor: Uint8Array,
          readerType: "default",
        };
        ArrayPrototypePush(this[_pendingPullIntos], pullIntoDescriptor);
      }
      readableStreamAddReadRequest(stream, readRequest);
      readableByteStreamControllerCallPullIfNeeded(this);
    }

    [_releaseSteps]() {
      if (this[_pendingPullIntos].length !== 0) {
        /** @type {PullIntoDescriptor} */
        const firstPendingPullInto = this[_pendingPullIntos][0];
        firstPendingPullInto.readerType = "none";
        this[_pendingPullIntos] = [firstPendingPullInto];
      }
    }
  }

  webidl.configurePrototype(ReadableByteStreamController);
  const ReadableByteStreamControllerPrototype =
    ReadableByteStreamController.prototype;

  /** @template R */
  class ReadableStreamDefaultController {
    /** @type {(reason: any) => Promise<void>} */
    [_cancelAlgorithm];
    /** @type {boolean} */
    [_closeRequested];
    /** @type {boolean} */
    [_pullAgain];
    /** @type {(controller: this) => Promise<void>} */
    [_pullAlgorithm];
    /** @type {boolean} */
    [_pulling];
    /** @type {Array<ValueWithSize<R>>} */
    [_queue];
    /** @type {number} */
    [_queueTotalSize];
    /** @type {boolean} */
    [_started];
    /** @type {number} */
    [_strategyHWM];
    /** @type {(chunk: R) => number} */
    [_strategySizeAlgorithm];
    /** @type {ReadableStream<R>} */
    [_stream];

    constructor() {
      webidl.illegalConstructor();
    }

    /** @returns {number | null} */
    get desiredSize() {
      webidl.assertBranded(this, ReadableStreamDefaultControllerPrototype);
      return readableStreamDefaultControllerGetDesiredSize(this);
    }

    /** @returns {void} */
    close() {
      webidl.assertBranded(this, ReadableStreamDefaultControllerPrototype);
      if (readableStreamDefaultControllerCanCloseOrEnqueue(this) === false) {
        throw new TypeError("The stream controller cannot close or enqueue.");
      }
      readableStreamDefaultControllerClose(this);
    }

    /**
     * @param {R} chunk
     * @returns {void}
     */
    enqueue(chunk = undefined) {
      webidl.assertBranded(this, ReadableStreamDefaultControllerPrototype);
      if (chunk !== undefined) {
        chunk = webidl.converters.any(chunk);
      }
      if (readableStreamDefaultControllerCanCloseOrEnqueue(this) === false) {
        throw new TypeError("The stream controller cannot close or enqueue.");
      }
      readableStreamDefaultControllerEnqueue(this, chunk);
    }

    /**
     * @param {any=} e
     * @returns {void}
     */
    error(e = undefined) {
      webidl.assertBranded(this, ReadableStreamDefaultControllerPrototype);
      if (e !== undefined) {
        e = webidl.converters.any(e);
      }
      readableStreamDefaultControllerError(this, e);
    }

    [SymbolFor("Deno.customInspect")](inspect) {
      return inspect(consoleInternal.createFilteredInspectProxy({
        object: this,
        evaluate: ObjectPrototypeIsPrototypeOf(
          ReadableStreamDefaultController.prototype,
          this,
        ),
        keys: ["desiredSize"],
      }));
    }

    /**
     * @param {any} reason
     * @returns {Promise<void>}
     */
    [_cancelSteps](reason) {
      resetQueue(this);
      const result = this[_cancelAlgorithm](reason);
      readableStreamDefaultControllerClearAlgorithms(this);
      return result;
    }

    /**
     * @param {ReadRequest<R>} readRequest
     * @returns {void}
     */
    [_pullSteps](readRequest) {
      const stream = this[_stream];
      if (this[_queue].length) {
        const chunk = dequeueValue(this);
        if (this[_closeRequested] && this[_queue].length === 0) {
          readableStreamDefaultControllerClearAlgorithms(this);
          readableStreamClose(stream);
        } else {
          readableStreamDefaultControllerCallPullIfNeeded(this);
        }
        readRequest.chunkSteps(chunk);
      } else {
        readableStreamAddReadRequest(stream, readRequest);
        readableStreamDefaultControllerCallPullIfNeeded(this);
      }
    }

    [_releaseSteps]() {
      return;
    }
  }

  webidl.configurePrototype(ReadableStreamDefaultController);
  const ReadableStreamDefaultControllerPrototype =
    ReadableStreamDefaultController.prototype;

  /**
   * @template I
   * @template O
   */
  class TransformStream {
    /** @type {boolean} */
    [_backpressure];
    /** @type {Deferred<void>} */
    [_backpressureChangePromise];
    /** @type {TransformStreamDefaultController<O>} */
    [_controller];
    /** @type {boolean} */
    [_detached];
    /** @type {ReadableStream<O>} */
    [_readable];
    /** @type {WritableStream<I>} */
    [_writable];

    /**
     * @param {Transformer<I, O>} transformer
     * @param {QueuingStrategy<I>} writableStrategy
     * @param {QueuingStrategy<O>} readableStrategy
     */
    constructor(
      transformer = undefined,
      writableStrategy = {},
      readableStrategy = {},
    ) {
      const prefix = "Failed to construct 'TransformStream'";
      if (transformer !== undefined) {
        transformer = webidl.converters.object(transformer, {
          prefix,
          context: "Argument 1",
        });
      }
      writableStrategy = webidl.converters.QueuingStrategy(writableStrategy, {
        prefix,
        context: "Argument 2",
      });
      readableStrategy = webidl.converters.QueuingStrategy(readableStrategy, {
        prefix,
        context: "Argument 2",
      });
      this[webidl.brand] = webidl.brand;
      if (transformer === undefined) {
        transformer = null;
      }
      const transformerDict = webidl.converters.Transformer(transformer, {
        prefix,
        context: "transformer",
      });
      if (transformerDict.readableType !== undefined) {
        throw new RangeError(
          `${prefix}: readableType transformers not supported.`,
        );
      }
      if (transformerDict.writableType !== undefined) {
        throw new RangeError(
          `${prefix}: writableType transformers not supported.`,
        );
      }
      const readableHighWaterMark = extractHighWaterMark(readableStrategy, 0);
      const readableSizeAlgorithm = extractSizeAlgorithm(readableStrategy);
      const writableHighWaterMark = extractHighWaterMark(writableStrategy, 1);
      const writableSizeAlgorithm = extractSizeAlgorithm(writableStrategy);
      /** @type {Deferred<void>} */
      const startPromise = new Deferred();
      initializeTransformStream(
        this,
        startPromise,
        writableHighWaterMark,
        writableSizeAlgorithm,
        readableHighWaterMark,
        readableSizeAlgorithm,
      );
      setUpTransformStreamDefaultControllerFromTransformer(
        this,
        transformer,
        transformerDict,
      );
      if (transformerDict.start) {
        startPromise.resolve(
          webidl.invokeCallbackFunction(
            transformerDict.start,
            [this[_controller]],
            transformer,
            webidl.converters.any,
            {
              prefix:
                "Failed to call 'start' on 'TransformStreamDefaultController'",
            },
          ),
        );
      } else {
        startPromise.resolve(undefined);
      }
    }

    /** @returns {ReadableStream<O>} */
    get readable() {
      webidl.assertBranded(this, TransformStreamPrototype);
      return this[_readable];
    }

    /** @returns {WritableStream<I>} */
    get writable() {
      webidl.assertBranded(this, TransformStreamPrototype);
      return this[_writable];
    }

    [SymbolFor("Deno.privateCustomInspect")](inspect) {
      return `${this.constructor.name} ${
        inspect({ readable: this.readable, writable: this.writable })
      }`;
    }
  }

  webidl.configurePrototype(TransformStream);
  const TransformStreamPrototype = TransformStream.prototype;

  /** @template O */
  class TransformStreamDefaultController {
    /** @type {(controller: this) => Promise<void>} */
    [_flushAlgorithm];
    /** @type {TransformStream<O>} */
    [_stream];
    /** @type {(chunk: O, controller: this) => Promise<void>} */
    [_transformAlgorithm];

    constructor() {
      webidl.illegalConstructor();
    }

    /** @returns {number | null} */
    get desiredSize() {
      webidl.assertBranded(this, TransformStreamDefaultController.prototype);
      const readableController = this[_stream][_readable][_controller];
      return readableStreamDefaultControllerGetDesiredSize(
        /** @type {ReadableStreamDefaultController<O>} */ readableController,
      );
    }

    /**
     * @param {O} chunk
     * @returns {void}
     */
    enqueue(chunk = undefined) {
      webidl.assertBranded(this, TransformStreamDefaultController.prototype);
      if (chunk !== undefined) {
        chunk = webidl.converters.any(chunk);
      }
      transformStreamDefaultControllerEnqueue(this, chunk);
    }

    /**
     * @param {any=} reason
     * @returns {void}
     */
    error(reason = undefined) {
      webidl.assertBranded(this, TransformStreamDefaultController.prototype);
      if (reason !== undefined) {
        reason = webidl.converters.any(reason);
      }
      transformStreamDefaultControllerError(this, reason);
    }

    /** @returns {void} */
    terminate() {
      webidl.assertBranded(this, TransformStreamDefaultControllerPrototype);
      transformStreamDefaultControllerTerminate(this);
    }

    [SymbolFor("Deno.customInspect")](inspect) {
      return inspect(consoleInternal.createFilteredInspectProxy({
        object: this,
        evaluate: ObjectPrototypeIsPrototypeOf(
          TransformStreamDefaultController.prototype,
          this,
        ),
        keys: ["desiredSize"],
      }));
    }
  }

  webidl.configurePrototype(TransformStreamDefaultController);
  const TransformStreamDefaultControllerPrototype =
    TransformStreamDefaultController.prototype;

  /** @template W */
  class WritableStream {
    /** @type {boolean} */
    [_backpressure];
    /** @type {Deferred<void> | undefined} */
    [_closeRequest];
    /** @type {WritableStreamDefaultController<W>} */
    [_controller];
    /** @type {boolean} */
    [_detached];
    /** @type {Deferred<void> | undefined} */
    [_inFlightWriteRequest];
    /** @type {Deferred<void> | undefined} */
    [_inFlightCloseRequest];
    /** @type {PendingAbortRequest | undefined} */
    [_pendingAbortRequest];
    /** @type {"writable" | "closed" | "erroring" | "errored"} */
    [_state];
    /** @type {any} */
    [_storedError];
    /** @type {WritableStreamDefaultWriter<W>} */
    [_writer];
    /** @type {Deferred<void>[]} */
    [_writeRequests];

    /**
     * @param {UnderlyingSink<W>=} underlyingSink
     * @param {QueuingStrategy<W>=} strategy
     */
    constructor(underlyingSink = undefined, strategy = {}) {
      const prefix = "Failed to construct 'WritableStream'";
      if (underlyingSink !== undefined) {
        underlyingSink = webidl.converters.object(underlyingSink, {
          prefix,
          context: "Argument 1",
        });
      }
      strategy = webidl.converters.QueuingStrategy(strategy, {
        prefix,
        context: "Argument 2",
      });
      this[webidl.brand] = webidl.brand;
      if (underlyingSink === undefined) {
        underlyingSink = null;
      }
      const underlyingSinkDict = webidl.converters.UnderlyingSink(
        underlyingSink,
        { prefix, context: "underlyingSink" },
      );
      if (underlyingSinkDict.type != null) {
        throw new RangeError(
          `${prefix}: WritableStream does not support 'type' in the underlying sink.`,
        );
      }
      initializeWritableStream(this);
      const sizeAlgorithm = extractSizeAlgorithm(strategy);
      const highWaterMark = extractHighWaterMark(strategy, 1);
      setUpWritableStreamDefaultControllerFromUnderlyingSink(
        this,
        underlyingSink,
        underlyingSinkDict,
        highWaterMark,
        sizeAlgorithm,
      );
    }

    /** @returns {boolean} */
    get locked() {
      webidl.assertBranded(this, WritableStreamPrototype);
      return isWritableStreamLocked(this);
    }

    /**
     * @param {any=} reason
     * @returns {Promise<void>}
     */
    abort(reason = undefined) {
      try {
        webidl.assertBranded(this, WritableStreamPrototype);
      } catch (err) {
        return PromiseReject(err);
      }
      if (reason !== undefined) {
        reason = webidl.converters.any(reason);
      }
      if (isWritableStreamLocked(this)) {
        return PromiseReject(
          new TypeError(
            "The writable stream is locked, therefore cannot be aborted.",
          ),
        );
      }
      return writableStreamAbort(this, reason);
    }

    /** @returns {Promise<void>} */
    close() {
      try {
        webidl.assertBranded(this, WritableStreamPrototype);
      } catch (err) {
        return PromiseReject(err);
      }
      if (isWritableStreamLocked(this)) {
        return PromiseReject(
          new TypeError(
            "The writable stream is locked, therefore cannot be closed.",
          ),
        );
      }
      if (writableStreamCloseQueuedOrInFlight(this) === true) {
        return PromiseReject(
          new TypeError("The writable stream is already closing."),
        );
      }
      return writableStreamClose(this);
    }

    /** @returns {WritableStreamDefaultWriter<W>} */
    getWriter() {
      webidl.assertBranded(this, WritableStreamPrototype);
      return acquireWritableStreamDefaultWriter(this);
    }

    [SymbolFor("Deno.privateCustomInspect")](inspect) {
      return `${this.constructor.name} ${inspect({ locked: this.locked })}`;
    }
  }

  webidl.configurePrototype(WritableStream);
  const WritableStreamPrototype = WritableStream.prototype;

  /** @template W */
  class WritableStreamDefaultWriter {
    /** @type {Deferred<void>} */
    [_closedPromise];

    /** @type {Deferred<void>} */
    [_readyPromise];

    /** @type {WritableStream<W>} */
    [_stream];

    /**
     * @param {WritableStream<W>} stream
     */
    constructor(stream) {
      const prefix = "Failed to construct 'WritableStreamDefaultWriter'";
      webidl.requiredArguments(arguments.length, 1, { prefix });
      stream = webidl.converters.WritableStream(stream, {
        prefix,
        context: "Argument 1",
      });
      this[webidl.brand] = webidl.brand;
      setUpWritableStreamDefaultWriter(this, stream);
    }

    /** @returns {Promise<void>} */
    get closed() {
      try {
        webidl.assertBranded(this, WritableStreamDefaultWriterPrototype);
      } catch (err) {
        return PromiseReject(err);
      }
      return this[_closedPromise].promise;
    }

    /** @returns {number} */
    get desiredSize() {
      webidl.assertBranded(this, WritableStreamDefaultWriterPrototype);
      if (this[_stream] === undefined) {
        throw new TypeError(
          "A writable stream is not associated with the writer.",
        );
      }
      return writableStreamDefaultWriterGetDesiredSize(this);
    }

    /** @returns {Promise<void>} */
    get ready() {
      try {
        webidl.assertBranded(this, WritableStreamDefaultWriterPrototype);
      } catch (err) {
        return PromiseReject(err);
      }
      return this[_readyPromise].promise;
    }

    /**
     * @param {any} reason
     * @returns {Promise<void>}
     */
    abort(reason = undefined) {
      try {
        webidl.assertBranded(this, WritableStreamDefaultWriterPrototype);
      } catch (err) {
        return PromiseReject(err);
      }
      if (reason !== undefined) {
        reason = webidl.converters.any(reason);
      }
      if (this[_stream] === undefined) {
        return PromiseReject(
          new TypeError("A writable stream is not associated with the writer."),
        );
      }
      return writableStreamDefaultWriterAbort(this, reason);
    }

    /** @returns {Promise<void>} */
    close() {
      try {
        webidl.assertBranded(this, WritableStreamDefaultWriterPrototype);
      } catch (err) {
        return PromiseReject(err);
      }
      const stream = this[_stream];
      if (stream === undefined) {
        return PromiseReject(
          new TypeError("A writable stream is not associated with the writer."),
        );
      }
      if (writableStreamCloseQueuedOrInFlight(stream) === true) {
        return PromiseReject(
          new TypeError("The associated stream is already closing."),
        );
      }
      return writableStreamDefaultWriterClose(this);
    }

    /** @returns {void} */
    releaseLock() {
      webidl.assertBranded(this, WritableStreamDefaultWriterPrototype);
      const stream = this[_stream];
      if (stream === undefined) {
        return;
      }
      assert(stream[_writer] !== undefined);
      writableStreamDefaultWriterRelease(this);
    }

    /**
     * @param {W} chunk
     * @returns {Promise<void>}
     */
    write(chunk = undefined) {
      try {
        webidl.assertBranded(this, WritableStreamDefaultWriterPrototype);
        if (chunk !== undefined) {
          chunk = webidl.converters.any(chunk);
        }
      } catch (err) {
        return PromiseReject(err);
      }
      if (this[_stream] === undefined) {
        return PromiseReject(
          new TypeError("A writable stream is not associate with the writer."),
        );
      }
      return writableStreamDefaultWriterWrite(this, chunk);
    }

    [SymbolFor("Deno.customInspect")](inspect) {
      return inspect(consoleInternal.createFilteredInspectProxy({
        object: this,
        evaluate: ObjectPrototypeIsPrototypeOf(
          WritableStreamDefaultWriter.prototype,
          this,
        ),
        keys: [
          "closed",
          "desiredSize",
          "ready",
        ],
      }));
    }
  }

  webidl.configurePrototype(WritableStreamDefaultWriter);
  const WritableStreamDefaultWriterPrototype =
    WritableStreamDefaultWriter.prototype;

  /** @template W */
  class WritableStreamDefaultController {
    /** @type {(reason?: any) => Promise<void>} */
    [_abortAlgorithm];
    /** @type {() => Promise<void>} */
    [_closeAlgorithm];
    /** @type {ValueWithSize<W | _close>[]} */
    [_queue];
    /** @type {number} */
    [_queueTotalSize];
    /** @type {boolean} */
    [_started];
    /** @type {number} */
    [_strategyHWM];
    /** @type {(chunk: W) => number} */
    [_strategySizeAlgorithm];
    /** @type {WritableStream<W>} */
    [_stream];
    /** @type {(chunk: W, controller: this) => Promise<void>} */
    [_writeAlgorithm];
    /** @type {AbortSignal} */
    [_signal];

    get signal() {
      webidl.assertBranded(this, WritableStreamDefaultControllerPrototype);
      return this[_signal];
    }

    constructor() {
      webidl.illegalConstructor();
    }

    /**
     * @param {any=} e
     * @returns {void}
     */
    error(e = undefined) {
      webidl.assertBranded(this, WritableStreamDefaultControllerPrototype);
      if (e !== undefined) {
        e = webidl.converters.any(e);
      }
      const state = this[_stream][_state];
      if (state !== "writable") {
        return;
      }
      writableStreamDefaultControllerError(this, e);
    }

    [SymbolFor("Deno.customInspect")](inspect) {
      return inspect(consoleInternal.createFilteredInspectProxy({
        object: this,
        evaluate: ObjectPrototypeIsPrototypeOf(
          WritableStreamDefaultController.prototype,
          this,
        ),
        keys: [],
      }));
    }

    /**
     * @param {any=} reason
     * @returns {Promise<void>}
     */
    [_abortSteps](reason) {
      const result = this[_abortAlgorithm](reason);
      writableStreamDefaultControllerClearAlgorithms(this);
      return result;
    }

    [_errorSteps]() {
      resetQueue(this);
    }
  }

  webidl.configurePrototype(WritableStreamDefaultController);
  const WritableStreamDefaultControllerPrototype =
    WritableStreamDefaultController.prototype;

  /**
   * @param {ReadableStream} stream
   */
  function createProxy(stream) {
    return stream.pipeThrough(new TransformStream());
  }

  webidl.converters.ReadableStream = webidl
    .createInterfaceConverter("ReadableStream", ReadableStream.prototype);
  webidl.converters.WritableStream = webidl
    .createInterfaceConverter("WritableStream", WritableStream.prototype);

  webidl.converters.ReadableStreamType = webidl.createEnumConverter(
    "ReadableStreamType",
    ["bytes"],
  );

  webidl.converters.UnderlyingSource = webidl
    .createDictionaryConverter("UnderlyingSource", [
      {
        key: "start",
        converter: webidl.converters.Function,
      },
      {
        key: "pull",
        converter: webidl.converters.Function,
      },
      {
        key: "cancel",
        converter: webidl.converters.Function,
      },
      {
        key: "type",
        converter: webidl.converters.ReadableStreamType,
      },
      {
        key: "autoAllocateChunkSize",
        converter: (V, opts) =>
          webidl.converters["unsigned long long"](V, {
            ...opts,
            enforceRange: true,
          }),
      },
    ]);
  webidl.converters.UnderlyingSink = webidl
    .createDictionaryConverter("UnderlyingSink", [
      {
        key: "start",
        converter: webidl.converters.Function,
      },
      {
        key: "write",
        converter: webidl.converters.Function,
      },
      {
        key: "close",
        converter: webidl.converters.Function,
      },
      {
        key: "abort",
        converter: webidl.converters.Function,
      },
      {
        key: "type",
        converter: webidl.converters.any,
      },
    ]);
  webidl.converters.Transformer = webidl
    .createDictionaryConverter("Transformer", [
      {
        key: "start",
        converter: webidl.converters.Function,
      },
      {
        key: "transform",
        converter: webidl.converters.Function,
      },
      {
        key: "flush",
        converter: webidl.converters.Function,
      },
      {
        key: "readableType",
        converter: webidl.converters.any,
      },
      {
        key: "writableType",
        converter: webidl.converters.any,
      },
    ]);
  webidl.converters.QueuingStrategy = webidl
    .createDictionaryConverter("QueuingStrategy", [
      {
        key: "highWaterMark",
        converter: webidl.converters["unrestricted double"],
      },
      {
        key: "size",
        converter: webidl.converters.Function,
      },
    ]);
  webidl.converters.QueuingStrategyInit = webidl
    .createDictionaryConverter("QueuingStrategyInit", [
      {
        key: "highWaterMark",
        converter: webidl.converters["unrestricted double"],
        required: true,
      },
    ]);

  webidl.converters.ReadableStreamIteratorOptions = webidl
    .createDictionaryConverter("ReadableStreamIteratorOptions", [
      {
        key: "preventCancel",
        defaultValue: false,
        converter: webidl.converters.boolean,
      },
    ]);

  webidl.converters.ReadableStreamReaderMode = webidl
    .createEnumConverter("ReadableStreamReaderMode", ["byob"]);
  webidl.converters.ReadableStreamGetReaderOptions = webidl
    .createDictionaryConverter("ReadableStreamGetReaderOptions", [{
      key: "mode",
      converter: webidl.converters.ReadableStreamReaderMode,
    }]);

  webidl.converters.ReadableWritablePair = webidl
    .createDictionaryConverter("ReadableWritablePair", [
      {
        key: "readable",
        converter: webidl.converters.ReadableStream,
        required: true,
      },
      {
        key: "writable",
        converter: webidl.converters.WritableStream,
        required: true,
      },
    ]);
  webidl.converters.StreamPipeOptions = webidl
    .createDictionaryConverter("StreamPipeOptions", [
      {
        key: "preventClose",
        defaultValue: false,
        converter: webidl.converters.boolean,
      },
      {
        key: "preventAbort",
        defaultValue: false,
        converter: webidl.converters.boolean,
      },
      {
        key: "preventCancel",
        defaultValue: false,
        converter: webidl.converters.boolean,
      },
      { key: "signal", converter: webidl.converters.AbortSignal },
    ]);

  window.__bootstrap.streams = {
    // Non-Public
    isReadableStreamDisturbed,
    errorReadableStream,
    createProxy,
    writableStreamClose,
    readableStreamClose,
    readableStreamForRid,
    getReadableStreamRid,
    Deferred,
    // Exposed in global runtime scope
    ByteLengthQueuingStrategy,
    CountQueuingStrategy,
    ReadableStream,
    ReadableStreamPrototype,
    ReadableStreamDefaultReader,
    TransformStream,
    WritableStream,
    WritableStreamDefaultWriter,
    WritableStreamDefaultController,
    ReadableByteStreamController,
    ReadableStreamBYOBReader,
    ReadableStreamBYOBRequest,
    ReadableStreamDefaultController,
    TransformStreamDefaultController,
  };
})(this);