1.index.js

            if (preventClose === false) {
              shutdownWithAction(function () {
                return WritableStreamDefaultWriterCloseWithErrorPropagation(writer);
              });
            } else {
              shutdown();
            }
          });
          if (WritableStreamCloseQueuedOrInFlight(dest) === true || dest._state === 'closed') {
            var destClosed = new TypeError('the destination writable stream closed before all data could be piped to it');
            if (preventCancel === false) {
              shutdownWithAction(function () {
                return ReadableStreamCancel(_this, destClosed);
              }, true, destClosed);
            } else {
              shutdown(true, destClosed);
            }
          }
          pipeLoop().catch(function (err) {
            currentWrite = Promise.resolve();
            rethrowAssertionErrorRejection(err);
          });
          function waitForWritesToFinish() {
            var oldCurrentWrite = currentWrite;
            return currentWrite.then(function () {
              return oldCurrentWrite !== currentWrite ? waitForWritesToFinish() : undefined;
            });
          }
          function isOrBecomesErrored(stream, promise, action) {
            if (stream._state === 'errored') {
              action(stream._storedError);
            } else {
              promise.catch(action).catch(rethrowAssertionErrorRejection);
            }
          }
          function isOrBecomesClosed(stream, promise, action) {
            if (stream._state === 'closed') {
              action();
            } else {
              promise.then(action).catch(rethrowAssertionErrorRejection);
            }
          }
          function shutdownWithAction(action, originalIsError, originalError) {
            if (shuttingDown === true) {
              return;
            }
            shuttingDown = true;
            if (dest._state === 'writable' && WritableStreamCloseQueuedOrInFlight(dest) === false) {
              waitForWritesToFinish().then(doTheRest);
            } else {
              doTheRest();
            }
            function doTheRest() {
              action().then(function () {
                return finalize(originalIsError, originalError);
              }, function (newError) {
                return finalize(true, newError);
              }).catch(rethrowAssertionErrorRejection);
            }
          }
          function shutdown(isError, error) {
            if (shuttingDown === true) {
              return;
            }
            shuttingDown = true;
            if (dest._state === 'writable' && WritableStreamCloseQueuedOrInFlight(dest) === false) {
              waitForWritesToFinish().then(function () {
                return finalize(isError, error);
              }).catch(rethrowAssertionErrorRejection);
            } else {
              finalize(isError, error);
            }
          }
          function finalize(isError, error) {
            WritableStreamDefaultWriterRelease(writer);
            ReadableStreamReaderGenericRelease(reader);
            if (isError) {
              reject(error);
            } else {
              resolve(undefined);
            }
          }
        });
      }
    }, {
      key: 'tee',
      value: function tee() {
        if (IsReadableStream(this) === false) {
          throw streamBrandCheckException('tee');
        }
        var branches = ReadableStreamTee(this, false);
        return createArrayFromList(branches);
      }
    }, {
      key: 'locked',
      get: function get() {
        if (IsReadableStream(this) === false) {
          throw streamBrandCheckException('locked');
        }
        return IsReadableStreamLocked(this);
      }
    }]);
    return ReadableStream;
  }();
  module.exports = {
    ReadableStream: ReadableStream,
    IsReadableStreamDisturbed: IsReadableStreamDisturbed,
    ReadableStreamDefaultControllerClose: ReadableStreamDefaultControllerClose,
    ReadableStreamDefaultControllerEnqueue: ReadableStreamDefaultControllerEnqueue,
    ReadableStreamDefaultControllerError: ReadableStreamDefaultControllerError,
    ReadableStreamDefaultControllerGetDesiredSize: ReadableStreamDefaultControllerGetDesiredSize
  };
  function AcquireReadableStreamBYOBReader(stream) {
    return new ReadableStreamBYOBReader(stream);
  }
  function AcquireReadableStreamDefaultReader(stream) {
    return new ReadableStreamDefaultReader(stream);
  }
  function IsReadableStream(x) {
    if (!typeIsObject(x)) {
      return false;
    }
    if (!Object.prototype.hasOwnProperty.call(x, '_readableStreamController')) {
      return false;
    }
    return true;
  }
  function IsReadableStreamDisturbed(stream) {
    assert(IsReadableStream(stream) === true, 'IsReadableStreamDisturbed should only be used on known readable streams');
    return stream._disturbed;
  }
  function IsReadableStreamLocked(stream) {
    assert(IsReadableStream(stream) === true, 'IsReadableStreamLocked should only be used on known readable streams');
    if (stream._reader === undefined) {
      return false;
    }
    return true;
  }
  function ReadableStreamTee(stream, cloneForBranch2) {
    assert(IsReadableStream(stream) === true);
    assert(typeof cloneForBranch2 === 'boolean');
    var reader = AcquireReadableStreamDefaultReader(stream);
    var teeState = {
      closedOrErrored: false,
      canceled1: false,
      canceled2: false,
      reason1: undefined,
      reason2: undefined
    };
    teeState.promise = new Promise(function (resolve) {
      teeState._resolve = resolve;
    });
    var pull = create_ReadableStreamTeePullFunction();
    pull._reader = reader;
    pull._teeState = teeState;
    pull._cloneForBranch2 = cloneForBranch2;
    var cancel1 = create_ReadableStreamTeeBranch1CancelFunction();
    cancel1._stream = stream;
    cancel1._teeState = teeState;
    var cancel2 = create_ReadableStreamTeeBranch2CancelFunction();
    cancel2._stream = stream;
    cancel2._teeState = teeState;
    var underlyingSource1 = Object.create(Object.prototype);
    createDataProperty(underlyingSource1, 'pull', pull);
    createDataProperty(underlyingSource1, 'cancel', cancel1);
    var branch1Stream = new ReadableStream(underlyingSource1);
    var underlyingSource2 = Object.create(Object.prototype);
    createDataProperty(underlyingSource2, 'pull', pull);
    createDataProperty(underlyingSource2, 'cancel', cancel2);
    var branch2Stream = new ReadableStream(underlyingSource2);
    pull._branch1 = branch1Stream._readableStreamController;
    pull._branch2 = branch2Stream._readableStreamController;
    reader._closedPromise.catch(function (r) {
      if (teeState.closedOrErrored === true) {
        return;
      }
      ReadableStreamDefaultControllerError(pull._branch1, r);
      ReadableStreamDefaultControllerError(pull._branch2, r);
      teeState.closedOrErrored = true;
    });
    return [branch1Stream, branch2Stream];
  }
  function create_ReadableStreamTeePullFunction() {
    function f() {
      var reader = f._reader,
          branch1 = f._branch1,
          branch2 = f._branch2,
          teeState = f._teeState;
      return ReadableStreamDefaultReaderRead(reader).then(function (result) {
        assert(typeIsObject(result));
        var value = result.value;
        var done = result.done;
        assert(typeof done === 'boolean');
        if (done === true && teeState.closedOrErrored === false) {
          if (teeState.canceled1 === false) {
            ReadableStreamDefaultControllerClose(branch1);
          }
          if (teeState.canceled2 === false) {
            ReadableStreamDefaultControllerClose(branch2);
          }
          teeState.closedOrErrored = true;
        }
        if (teeState.closedOrErrored === true) {
          return;
        }
        var value1 = value;
        var value2 = value;
        if (teeState.canceled1 === false) {
          ReadableStreamDefaultControllerEnqueue(branch1, value1);
        }
        if (teeState.canceled2 === false) {
          ReadableStreamDefaultControllerEnqueue(branch2, value2);
        }
      });
    }
    return f;
  }
  function create_ReadableStreamTeeBranch1CancelFunction() {
    function f(reason) {
      var stream = f._stream,
          teeState = f._teeState;
      teeState.canceled1 = true;
      teeState.reason1 = reason;
      if (teeState.canceled2 === true) {
        var compositeReason = createArrayFromList([teeState.reason1, teeState.reason2]);
        var cancelResult = ReadableStreamCancel(stream, compositeReason);
        teeState._resolve(cancelResult);
      }
      return teeState.promise;
    }
    return f;
  }
  function create_ReadableStreamTeeBranch2CancelFunction() {
    function f(reason) {
      var stream = f._stream,
          teeState = f._teeState;
      teeState.canceled2 = true;
      teeState.reason2 = reason;
      if (teeState.canceled1 === true) {
        var compositeReason = createArrayFromList([teeState.reason1, teeState.reason2]);
        var cancelResult = ReadableStreamCancel(stream, compositeReason);
        teeState._resolve(cancelResult);
      }
      return teeState.promise;
    }
    return f;
  }
  function ReadableStreamAddReadIntoRequest(stream) {
    assert(IsReadableStreamBYOBReader(stream._reader) === true);
    assert(stream._state === 'readable' || stream._state === 'closed');
    var promise = new Promise(function (resolve, reject) {
      var readIntoRequest = {
        _resolve: resolve,
        _reject: reject
      };
      stream._reader._readIntoRequests.push(readIntoRequest);
    });
    return promise;
  }
  function ReadableStreamAddReadRequest(stream) {
    assert(IsReadableStreamDefaultReader(stream._reader) === true);
    assert(stream._state === 'readable');
    var promise = new Promise(function (resolve, reject) {
      var readRequest = {
        _resolve: resolve,
        _reject: reject
      };
      stream._reader._readRequests.push(readRequest);
    });
    return promise;
  }
  function ReadableStreamCancel(stream, reason) {
    stream._disturbed = true;
    if (stream._state === 'closed') {
      return Promise.resolve(undefined);
    }
    if (stream._state === 'errored') {
      return Promise.reject(stream._storedError);
    }
    ReadableStreamClose(stream);
    var sourceCancelPromise = stream._readableStreamController.__cancelSteps(reason);
    return sourceCancelPromise.then(function () {
      return undefined;
    });
  }
  function ReadableStreamClose(stream) {
    assert(stream._state === 'readable');
    stream._state = 'closed';
    var reader = stream._reader;
    if (reader === undefined) {
      return undefined;
    }
    if (IsReadableStreamDefaultReader(reader) === true) {
      for (var i = 0; i < reader._readRequests.length; i++) {
        var _resolve = reader._readRequests[i]._resolve;
        _resolve(CreateIterResultObject(undefined, true));
      }
      reader._readRequests = [];
    }
    defaultReaderClosedPromiseResolve(reader);
    return undefined;
  }
  function ReadableStreamError(stream, e) {
    assert(IsReadableStream(stream) === true, 'stream must be ReadableStream');
    assert(stream._state === 'readable', 'state must be readable');
    stream._state = 'errored';
    stream._storedError = e;
    var reader = stream._reader;
    if (reader === undefined) {
      return undefined;
    }
    if (IsReadableStreamDefaultReader(reader) === true) {
      for (var i = 0; i < reader._readRequests.length; i++) {
        var readRequest = reader._readRequests[i];
        readRequest._reject(e);
      }
      reader._readRequests = [];
    } else {
      assert(IsReadableStreamBYOBReader(reader), 'reader must be ReadableStreamBYOBReader');
      for (var _i = 0; _i < reader._readIntoRequests.length; _i++) {
        var readIntoRequest = reader._readIntoRequests[_i];
        readIntoRequest._reject(e);
      }
      reader._readIntoRequests = [];
    }
    defaultReaderClosedPromiseReject(reader, e);
    reader._closedPromise.catch(function () {});
  }
  function ReadableStreamFulfillReadIntoRequest(stream, chunk, done) {
    var reader = stream._reader;
    assert(reader._readIntoRequests.length > 0);
    var readIntoRequest = reader._readIntoRequests.shift();
    readIntoRequest._resolve(CreateIterResultObject(chunk, done));
  }
  function ReadableStreamFulfillReadRequest(stream, chunk, done) {
    var reader = stream._reader;
    assert(reader._readRequests.length > 0);
    var readRequest = reader._readRequests.shift();
    readRequest._resolve(CreateIterResultObject(chunk, done));
  }
  function ReadableStreamGetNumReadIntoRequests(stream) {
    return stream._reader._readIntoRequests.length;
  }
  function ReadableStreamGetNumReadRequests(stream) {
    return stream._reader._readRequests.length;
  }
  function ReadableStreamHasBYOBReader(stream) {
    var reader = stream._reader;
    if (reader === undefined) {
      return false;
    }
    if (IsReadableStreamBYOBReader(reader) === false) {
      return false;
    }
    return true;
  }
  function ReadableStreamHasDefaultReader(stream) {
    var reader = stream._reader;
    if (reader === undefined) {
      return false;
    }
    if (IsReadableStreamDefaultReader(reader) === false) {
      return false;
    }
    return true;
  }
  var ReadableStreamDefaultReader = function () {
    function ReadableStreamDefaultReader(stream) {
      _classCallCheck(this, ReadableStreamDefaultReader);
      if (IsReadableStream(stream) === false) {
        throw new TypeError('ReadableStreamDefaultReader can only be constructed with a ReadableStream instance');
      }
      if (IsReadableStreamLocked(stream) === true) {
        throw new TypeError('This stream has already been locked for exclusive reading by another reader');
      }
      ReadableStreamReaderGenericInitialize(this, stream);
      this._readRequests = [];
    }
    _createClass(ReadableStreamDefaultReader, [{
      key: 'cancel',
      value: function cancel(reason) {
        if (IsReadableStreamDefaultReader(this) === false) {
          return Promise.reject(defaultReaderBrandCheckException('cancel'));
        }
        if (this._ownerReadableStream === undefined) {
          return Promise.reject(readerLockException('cancel'));
        }
        return ReadableStreamReaderGenericCancel(this, reason);
      }
    }, {
      key: 'read',
      value: function read() {
        if (IsReadableStreamDefaultReader(this) === false) {
          return Promise.reject(defaultReaderBrandCheckException('read'));
        }
        if (this._ownerReadableStream === undefined) {
          return Promise.reject(readerLockException('read from'));
        }
        return ReadableStreamDefaultReaderRead(this);
      }
    }, {
      key: 'releaseLock',
      value: function releaseLock() {
        if (IsReadableStreamDefaultReader(this) === false) {
          throw defaultReaderBrandCheckException('releaseLock');
        }
        if (this._ownerReadableStream === undefined) {
          return;
        }
        if (this._readRequests.length > 0) {
          throw new TypeError('Tried to release a reader lock when that reader has pending read() calls un-settled');
        }
        ReadableStreamReaderGenericRelease(this);
      }
    }, {
      key: 'closed',
      get: function get() {
        if (IsReadableStreamDefaultReader(this) === false) {
          return Promise.reject(defaultReaderBrandCheckException('closed'));
        }
        return this._closedPromise;
      }
    }]);
    return ReadableStreamDefaultReader;
  }();
  var ReadableStreamBYOBReader = function () {
    function ReadableStreamBYOBReader(stream) {
      _classCallCheck(this, ReadableStreamBYOBReader);
      if (!IsReadableStream(stream)) {
        throw new TypeError('ReadableStreamBYOBReader can only be constructed with a ReadableStream instance given a ' + 'byte source');
      }
      if (IsReadableByteStreamController(stream._readableStreamController) === false) {
        throw new TypeError('Cannot construct a ReadableStreamBYOBReader for a stream not constructed with a byte ' + 'source');
      }
      if (IsReadableStreamLocked(stream)) {
        throw new TypeError('This stream has already been locked for exclusive reading by another reader');
      }
      ReadableStreamReaderGenericInitialize(this, stream);
      this._readIntoRequests = [];
    }
    _createClass(ReadableStreamBYOBReader, [{
      key: 'cancel',
      value: function cancel(reason) {
        if (!IsReadableStreamBYOBReader(this)) {
          return Promise.reject(byobReaderBrandCheckException('cancel'));
        }
        if (this._ownerReadableStream === undefined) {
          return Promise.reject(readerLockException('cancel'));
        }
        return ReadableStreamReaderGenericCancel(this, reason);
      }
    }, {
      key: 'read',
      value: function read(view) {
        if (!IsReadableStreamBYOBReader(this)) {
          return Promise.reject(byobReaderBrandCheckException('read'));
        }
        if (this._ownerReadableStream === undefined) {
          return Promise.reject(readerLockException('read from'));
        }
        if (!ArrayBuffer.isView(view)) {
          return Promise.reject(new TypeError('view must be an array buffer view'));
        }
        if (view.byteLength === 0) {
          return Promise.reject(new TypeError('view must have non-zero byteLength'));
        }
        return ReadableStreamBYOBReaderRead(this, view);
      }
    }, {
      key: 'releaseLock',
      value: function releaseLock() {
        if (!IsReadableStreamBYOBReader(this)) {
          throw byobReaderBrandCheckException('releaseLock');
        }
        if (this._ownerReadableStream === undefined) {
          return;
        }
        if (this._readIntoRequests.length > 0) {
          throw new TypeError('Tried to release a reader lock when that reader has pending read() calls un-settled');
        }
        ReadableStreamReaderGenericRelease(this);
      }
    }, {
      key: 'closed',
      get: function get() {
        if (!IsReadableStreamBYOBReader(this)) {
          return Promise.reject(byobReaderBrandCheckException('closed'));
        }
        return this._closedPromise;
      }
    }]);
    return ReadableStreamBYOBReader;
  }();
  function IsReadableStreamBYOBReader(x) {
    if (!typeIsObject(x)) {
      return false;
    }
    if (!Object.prototype.hasOwnProperty.call(x, '_readIntoRequests')) {
      return false;
    }
    return true;
  }
  function IsReadableStreamDefaultReader(x) {
    if (!typeIsObject(x)) {
      return false;
    }
    if (!Object.prototype.hasOwnProperty.call(x, '_readRequests')) {
      return false;
    }
    return true;
  }
  function ReadableStreamReaderGenericInitialize(reader, stream) {
    reader._ownerReadableStream = stream;
    stream._reader = reader;
    if (stream._state === 'readable') {
      defaultReaderClosedPromiseInitialize(reader);
    } else if (stream._state === 'closed') {
      defaultReaderClosedPromiseInitializeAsResolved(reader);
    } else {
      assert(stream._state === 'errored', 'state must be errored');
      defaultReaderClosedPromiseInitializeAsRejected(reader, stream._storedError);
      reader._closedPromise.catch(function () {});
    }
  }
  function ReadableStreamReaderGenericCancel(reader, reason) {
    var stream = reader._ownerReadableStream;
    assert(stream !== undefined);
    return ReadableStreamCancel(stream, reason);
  }
  function ReadableStreamReaderGenericRelease(reader) {
    assert(reader._ownerReadableStream !== undefined);
    assert(reader._ownerReadableStream._reader === reader);
    if (reader._ownerReadableStream._state === 'readable') {
      defaultReaderClosedPromiseReject(reader, new TypeError('Reader was released and can no longer be used to monitor the stream\'s closedness'));
    } else {
      defaultReaderClosedPromiseResetToRejected(reader, new TypeError('Reader was released and can no longer be used to monitor the stream\'s closedness'));
    }
    reader._closedPromise.catch(function () {});
    reader._ownerReadableStream._reader = undefined;
    reader._ownerReadableStream = undefined;
  }
  function ReadableStreamBYOBReaderRead(reader, view) {
    var stream = reader._ownerReadableStream;
    assert(stream !== undefined);
    stream._disturbed = true;
    if (stream._state === 'errored') {
      return Promise.reject(stream._storedError);
    }
    return ReadableByteStreamControllerPullInto(stream._readableStreamController, view);
  }
  function ReadableStreamDefaultReaderRead(reader) {
    var stream = reader._ownerReadableStream;
    assert(stream !== undefined);
    stream._disturbed = true;
    if (stream._state === 'closed') {
      return Promise.resolve(CreateIterResultObject(undefined, true));
    }
    if (stream._state === 'errored') {
      return Promise.reject(stream._storedError);
    }
    assert(stream._state === 'readable');
    return stream._readableStreamController.__pullSteps();
  }
  var ReadableStreamDefaultController = function () {
    function ReadableStreamDefaultController(stream, underlyingSource, size, highWaterMark) {
      _classCallCheck(this, ReadableStreamDefaultController);
      if (IsReadableStream(stream) === false) {
        throw new TypeError('ReadableStreamDefaultController can only be constructed with a ReadableStream instance');
      }
      if (stream._readableStreamController !== undefined) {
        throw new TypeError('ReadableStreamDefaultController instances can only be created by the ReadableStream constructor');
      }
      this._controlledReadableStream = stream;
      this._underlyingSource = underlyingSource;
      this._queue = undefined;
      this._queueTotalSize = undefined;
      ResetQueue(this);
      this._started = false;
      this._closeRequested = false;
      this._pullAgain = false;
      this._pulling = false;
      var normalizedStrategy = ValidateAndNormalizeQueuingStrategy(size, highWaterMark);
      this._strategySize = normalizedStrategy.size;
      this._strategyHWM = normalizedStrategy.highWaterMark;
      var controller = this;
      var startResult = InvokeOrNoop(underlyingSource, 'start', [this]);
      Promise.resolve(startResult).then(function () {
        controller._started = true;
        assert(controller._pulling === false);
        assert(controller._pullAgain === false);
        ReadableStreamDefaultControllerCallPullIfNeeded(controller);
      }, function (r) {
        ReadableStreamDefaultControllerErrorIfNeeded(controller, r);
      }).catch(rethrowAssertionErrorRejection);
    }
    _createClass(ReadableStreamDefaultController, [{
      key: 'close',
      value: function close() {
        if (IsReadableStreamDefaultController(this) === false) {
          throw defaultControllerBrandCheckException('close');
        }
        if (this._closeRequested === true) {
          throw new TypeError('The stream has already been closed; do not close it again!');
        }
        var state = this._controlledReadableStream._state;
        if (state !== 'readable') {
          throw new TypeError('The stream (in ' + state + ' state) is not in the readable state and cannot be closed');
        }
        ReadableStreamDefaultControllerClose(this);
      }
    }, {
      key: 'enqueue',
      value: function enqueue(chunk) {
        if (IsReadableStreamDefaultController(this) === false) {
          throw defaultControllerBrandCheckException('enqueue');
        }
        if (this._closeRequested === true) {
          throw new TypeError('stream is closed or draining');
        }
        var state = this._controlledReadableStream._state;
        if (state !== 'readable') {
          throw new TypeError('The stream (in ' + state + ' state) is not in the readable state and cannot be enqueued to');
        }
        return ReadableStreamDefaultControllerEnqueue(this, chunk);
      }
    }, {
      key: 'error',
      value: function error(e) {
        if (IsReadableStreamDefaultController(this) === false) {
          throw defaultControllerBrandCheckException('error');
        }
        var stream = this._controlledReadableStream;
        if (stream._state !== 'readable') {
          throw new TypeError('The stream is ' + stream._state + ' and so cannot be errored');
        }
        ReadableStreamDefaultControllerError(this, e);
      }
    }, {
      key: '__cancelSteps',
      value: function __cancelSteps(reason) {
        ResetQueue(this);
        return PromiseInvokeOrNoop(this._underlyingSource, 'cancel', [reason]);
      }
    }, {
      key: '__pullSteps',
      value: function __pullSteps() {
        var stream = this._controlledReadableStream;
        if (this._queue.length > 0) {
          var chunk = DequeueValue(this);
          if (this._closeRequested === true && this._queue.length === 0) {
            ReadableStreamClose(stream);
          } else {
            ReadableStreamDefaultControllerCallPullIfNeeded(this);
          }
          return Promise.resolve(CreateIterResultObject(chunk, false));
        }
        var pendingPromise = ReadableStreamAddReadRequest(stream);
        ReadableStreamDefaultControllerCallPullIfNeeded(this);
        return pendingPromise;
      }
    }, {
      key: 'desiredSize',
      get: function get() {
        if (IsReadableStreamDefaultController(this) === false) {
          throw defaultControllerBrandCheckException('desiredSize');
        }
        return ReadableStreamDefaultControllerGetDesiredSize(this);
      }
    }]);
    return ReadableStreamDefaultController;
  }();
  function IsReadableStreamDefaultController(x) {
    if (!typeIsObject(x)) {
      return false;
    }
    if (!Object.prototype.hasOwnProperty.call(x, '_underlyingSource')) {
      return false;
    }
    return true;
  }
  function ReadableStreamDefaultControllerCallPullIfNeeded(controller) {
    var shouldPull = ReadableStreamDefaultControllerShouldCallPull(controller);
    if (shouldPull === false) {
      return undefined;
    }
    if (controller._pulling === true) {
      controller._pullAgain = true;
      return undefined;
    }
    assert(controller._pullAgain === false);
    controller._pulling = true;
    var pullPromise = PromiseInvokeOrNoop(controller._underlyingSource, 'pull', [controller]);
    pullPromise.then(function () {
      controller._pulling = false;
      if (controller._pullAgain === true) {
        controller._pullAgain = false;
        return ReadableStreamDefaultControllerCallPullIfNeeded(controller);
      }
      return undefined;
    }, function (e) {
      ReadableStreamDefaultControllerErrorIfNeeded(controller, e);
    }).catch(rethrowAssertionErrorRejection);
    return undefined;
  }
  function ReadableStreamDefaultControllerShouldCallPull(controller) {
    var stream = controller._controlledReadableStream;
    if (stream._state === 'closed' || stream._state === 'errored') {
      return false;
    }
    if (controller._closeRequested === true) {
      return false;
    }
    if (controller._started === false) {
      return false;
    }
    if (IsReadableStreamLocked(stream) === true && ReadableStreamGetNumReadRequests(stream) > 0) {
      return true;
    }
    var desiredSize = ReadableStreamDefaultControllerGetDesiredSize(controller);
    if (desiredSize > 0) {
      return true;
    }
    return false;
  }
  function ReadableStreamDefaultControllerClose(controller) {
    var stream = controller._controlledReadableStream;
    assert(controller._closeRequested === false);
    assert(stream._state === 'readable');
    controller._closeRequested = true;
    if (controller._queue.length === 0) {
      ReadableStreamClose(stream);
    }
  }
  function ReadableStreamDefaultControllerEnqueue(controller, chunk) {
    var stream = controller._controlledReadableStream;
    assert(controller._closeRequested === false);
    assert(stream._state === 'readable');
    if (IsReadableStreamLocked(stream) === true && ReadableStreamGetNumReadRequests(stream) > 0) {
      ReadableStreamFulfillReadRequest(stream, chunk, false);
    } else {
      var chunkSize = 1;
      if (controller._strategySize !== undefined) {
        var strategySize = controller._strategySize;
        try {
          chunkSize = strategySize(chunk);
        } catch (chunkSizeE) {
          ReadableStreamDefaultControllerErrorIfNeeded(controller, chunkSizeE);
          throw chunkSizeE;
        }
      }
      try {
        EnqueueValueWithSize(controller, chunk, chunkSize);
      } catch (enqueueE) {
        ReadableStreamDefaultControllerErrorIfNeeded(controller, enqueueE);
        throw enqueueE;
      }
    }
    ReadableStreamDefaultControllerCallPullIfNeeded(controller);
    return undefined;
  }
  function ReadableStreamDefaultControllerError(controller, e) {
    var stream = controller._controlledReadableStream;
    assert(stream._state === 'readable');
    ResetQueue(controller);
    ReadableStreamError(stream, e);
  }
  function ReadableStreamDefaultControllerErrorIfNeeded(controller, e) {
    if (controller._controlledReadableStream._state === 'readable') {
      ReadableStreamDefaultControllerError(controller, e);
    }
  }
  function ReadableStreamDefaultControllerGetDesiredSize(controller) {
    var stream = controller._controlledReadableStream;
    var state = stream._state;
    if (state === 'errored') {
      return null;
    }
    if (state === 'closed') {
      return 0;
    }
    return controller._strategyHWM - controller._queueTotalSize;
  }
  var ReadableStreamBYOBRequest = function () {
    function ReadableStreamBYOBRequest(controller, view) {
      _classCallCheck(this, ReadableStreamBYOBRequest);
      this._associatedReadableByteStreamController = controller;
      this._view = view;
    }
    _createClass(ReadableStreamBYOBRequest, [{
      key: 'respond',
      value: function respond(bytesWritten) {
        if (IsReadableStreamBYOBRequest(this) === false) {
          throw byobRequestBrandCheckException('respond');
        }
        if (this._associatedReadableByteStreamController === undefined) {
          throw new TypeError('This BYOB request has been invalidated');
        }
        ReadableByteStreamControllerRespond(this._associatedReadableByteStreamController, bytesWritten);
      }
    }, {
      key: 'respondWithNewView',
      value: function respondWithNewView(view) {
        if (IsReadableStreamBYOBRequest(this) === false) {
          throw byobRequestBrandCheckException('respond');
        }
        if (this._associatedReadableByteStreamController === undefined) {
          throw new TypeError('This BYOB request has been invalidated');
        }
        if (!ArrayBuffer.isView(view)) {
          throw new TypeError('You can only respond with array buffer views');
        }
        ReadableByteStreamControllerRespondWithNewView(this._associatedReadableByteStreamController, view);
      }
    }, {
      key: 'view',
      get: function get() {
        return this._view;
      }
    }]);
    return ReadableStreamBYOBRequest;
  }();
  var ReadableByteStreamController = function () {
    function ReadableByteStreamController(stream, underlyingByteSource, highWaterMark) {
      _classCallCheck(this, ReadableByteStreamController);
      if (IsReadableStream(stream) === false) {
        throw new TypeError('ReadableByteStreamController can only be constructed with a ReadableStream instance given ' + 'a byte source');
      }
      if (stream._readableStreamController !== undefined) {
        throw new TypeError('ReadableByteStreamController instances can only be created by the ReadableStream constructor given a byte ' + 'source');
      }
      this._controlledReadableStream = stream;
      this._underlyingByteSource = underlyingByteSource;
      this._pullAgain = false;
      this._pulling = false;
      ReadableByteStreamControllerClearPendingPullIntos(this);
      this._queue = this._queueTotalSize = undefined;
      ResetQueue(this);
      this._closeRequested = false;
      this._started = false;
      this._strategyHWM = ValidateAndNormalizeHighWaterMark(highWaterMark);
      var autoAllocateChunkSize = underlyingByteSource.autoAllocateChunkSize;
      if (autoAllocateChunkSize !== undefined) {
        if (Number.isInteger(autoAllocateChunkSize) === false || autoAllocateChunkSize <= 0) {
          throw new RangeError('autoAllocateChunkSize must be a positive integer');
        }
      }
      this._autoAllocateChunkSize = autoAllocateChunkSize;
      this._pendingPullIntos = [];
      var controller = this;
      var startResult = InvokeOrNoop(underlyingByteSource, 'start', [this]);
      Promise.resolve(startResult).then(function () {
        controller._started = true;
        assert(controller._pulling === false);
        assert(controller._pullAgain === false);
        ReadableByteStreamControllerCallPullIfNeeded(controller);
      }, function (r) {
        if (stream._state === 'readable') {
          ReadableByteStreamControllerError(controller, r);
        }
      }).catch(rethrowAssertionErrorRejection);
    }
    _createClass(ReadableByteStreamController, [{
      key: 'close',
      value: function close() {
        if (IsReadableByteStreamController(this) === false) {
          throw byteStreamControllerBrandCheckException('close');
        }
        if (this._closeRequested === true) {
          throw new TypeError('The stream has already been closed; do not close it again!');
        }
        var state = this._controlledReadableStream._state;
        if (state !== 'readable') {
          throw new TypeError('The stream (in ' + state + ' state) is not in the readable state and cannot be closed');
        }
        ReadableByteStreamControllerClose(this);
      }
    }, {
      key: 'enqueue',
      value: function enqueue(chunk) {
        if (IsReadableByteStreamController(this) === false) {
          throw byteStreamControllerBrandCheckException('enqueue');
        }
        if (this._closeRequested === true) {
          throw new TypeError('stream is closed or draining');
        }
        var state = this._controlledReadableStream._state;
        if (state !== 'readable') {
          throw new TypeError('The stream (in ' + state + ' state) is not in the readable state and cannot be enqueued to');
        }
        if (!ArrayBuffer.isView(chunk)) {
          throw new TypeError('You can only enqueue array buffer views when using a ReadableByteStreamController');
        }
        ReadableByteStreamControllerEnqueue(this, chunk);
      }
    }, {
      key: 'error',
      value: function error(e) {
        if (IsReadableByteStreamController(this) === false) {
          throw byteStreamControllerBrandCheckException('error');
        }
        var stream = this._controlledReadableStream;
        if (stream._state !== 'readable') {
          throw new TypeError('The stream is ' + stream._state + ' and so cannot be errored');
        }
        ReadableByteStreamControllerError(this, e);
      }
    }, {
      key: '__cancelSteps',
      value: function __cancelSteps(reason) {
        if (this._pendingPullIntos.length > 0) {
          var firstDescriptor = this._pendingPullIntos[0];
          firstDescriptor.bytesFilled = 0;
        }
        ResetQueue(this);
        return PromiseInvokeOrNoop(this._underlyingByteSource, 'cancel', [reason]);
      }
    }, {
      key: '__pullSteps',
      value: function __pullSteps() {
        var stream = this._controlledReadableStream;
        assert(ReadableStreamHasDefaultReader(stream) === true);
        if (this._queueTotalSize > 0) {
          assert(ReadableStreamGetNumReadRequests(stream) === 0);
          var entry = this._queue.shift();
          this._queueTotalSize -= entry.byteLength;
          ReadableByteStreamControllerHandleQueueDrain(this);
          var view = void 0;
          try {
            view = new Uint8Array(entry.buffer, entry.byteOffset, entry.byteLength);
          } catch (viewE) {
            return Promise.reject(viewE);
          }
          return Promise.resolve(CreateIterResultObject(view, false));
        }
        var autoAllocateChunkSize = this._autoAllocateChunkSize;
        if (autoAllocateChunkSize !== undefined) {
          var buffer = void 0;
          try {
            buffer = new ArrayBuffer(autoAllocateChunkSize);
          } catch (bufferE) {
            return Promise.reject(bufferE);
          }
          var pullIntoDescriptor = {
            buffer: buffer,
            byteOffset: 0,
            byteLength: autoAllocateChunkSize,
            bytesFilled: 0,
            elementSize: 1,
            ctor: Uint8Array,
            readerType: 'default'
          };
          this._pendingPullIntos.push(pullIntoDescriptor);
        }
        var promise = ReadableStreamAddReadRequest(stream);
        ReadableByteStreamControllerCallPullIfNeeded(this);
        return promise;
      }
    }, {
      key: 'byobRequest',
      get: function get() {
        if (IsReadableByteStreamController(this) === false) {
          throw byteStreamControllerBrandCheckException('byobRequest');
        }
        if (this._byobRequest === undefined && this._pendingPullIntos.length > 0) {
          var firstDescriptor = this._pendingPullIntos[0];
          var view = new Uint8Array(firstDescriptor.buffer, firstDescriptor.byteOffset + firstDescriptor.bytesFilled, firstDescriptor.byteLength - firstDescriptor.bytesFilled);
          this._byobRequest = new ReadableStreamBYOBRequest(this, view);
        }
        return this._byobRequest;
      }
    }, {
      key: 'desiredSize',
      get: function get() {
        if (IsReadableByteStreamController(this) === false) {
          throw byteStreamControllerBrandCheckException('desiredSize');
        }
        return ReadableByteStreamControllerGetDesiredSize(this);
      }
    }]);
    return ReadableByteStreamController;
  }();
  function IsReadableByteStreamController(x) {
    if (!typeIsObject(x)) {
      return false;
    }
    if (!Object.prototype.hasOwnProperty.call(x, '_underlyingByteSource')) {
      return false;
    }
    return true;
  }
  function IsReadableStreamBYOBRequest(x) {
    if (!typeIsObject(x)) {
      return false;
    }
    if (!Object.prototype.hasOwnProperty.call(x, '_associatedReadableByteStreamController')) {
      return false;
    }
    return true;
  }
  function ReadableByteStreamControllerCallPullIfNeeded(controller) {