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How to use ifIsObjectAndHasAPromiseIsHandledInternalSlotSetPromiseIsHandledToTrue method in wpt

Best JavaScript code snippet using wpt

readable-stream.js

Source:readable-stream.js

...67    throw new RangeError('Invalid mode is specified');68  }69  pipeThrough({ writable, readable }, options) {70    const promise = this.pipeTo(writable, options);71    ifIsObjectAndHasAPromiseIsHandledInternalSlotSetPromiseIsHandledToTrue(promise);72    return readable;73  }74  pipeTo(dest, { preventClose, preventAbort, preventCancel } = {}) {75    if (IsReadableStream(this) === false) {76      return Promise.reject(streamBrandCheckException('pipeTo'));77    }78    if (IsWritableStream(dest) === false) {79      return Promise.reject(80        new TypeError('ReadableStream.prototype.pipeTo\'s first argument must be a WritableStream'));81    }82    preventClose = Boolean(preventClose);83    preventAbort = Boolean(preventAbort);84    preventCancel = Boolean(preventCancel);85    if (IsReadableStreamLocked(this) === true) {86      return Promise.reject(new TypeError('ReadableStream.prototype.pipeTo cannot be used on a locked ReadableStream'));87    }88    if (IsWritableStreamLocked(dest) === true) {89      return Promise.reject(new TypeError('ReadableStream.prototype.pipeTo cannot be used on a locked WritableStream'));90    }91    const reader = AcquireReadableStreamDefaultReader(this);92    const writer = AcquireWritableStreamDefaultWriter(dest);93    let shuttingDown = false;94    // This is used to keep track of the spec's requirement that we wait for ongoing writes during shutdown.95    let currentWrite = Promise.resolve();96    return new Promise((resolve, reject) => {97      // Using reader and writer, read all chunks from this and write them to dest98      // - Backpressure must be enforced99      // - Shutdown must stop all activity100      function pipeLoop() {101        currentWrite = Promise.resolve();102        if (shuttingDown === true) {103          return Promise.resolve();104        }105        return writer._readyPromise.then(() => {106          return ReadableStreamDefaultReaderRead(reader).then(({ value, done }) => {107            if (done === true) {108              return;109            }110            currentWrite = WritableStreamDefaultWriterWrite(writer, value).catch(() => {});111          });112        })113        .then(pipeLoop);114      }115      // Errors must be propagated forward116      isOrBecomesErrored(this, reader._closedPromise, storedError => {117        if (preventAbort === false) {118          shutdownWithAction(() => WritableStreamAbort(dest, storedError), true, storedError);119        } else {120          shutdown(true, storedError);121        }122      });123      // Errors must be propagated backward124      isOrBecomesErrored(dest, writer._closedPromise, storedError => {125        if (preventCancel === false) {126          shutdownWithAction(() => ReadableStreamCancel(this, storedError), true, storedError);127        } else {128          shutdown(true, storedError);129        }130      });131      // Closing must be propagated forward132      isOrBecomesClosed(this, reader._closedPromise, () => {133        if (preventClose === false) {134          shutdownWithAction(() => WritableStreamDefaultWriterCloseWithErrorPropagation(writer));135        } else {136          shutdown();137        }138      });139      // Closing must be propagated backward140      if (WritableStreamCloseQueuedOrInFlight(dest) === true || dest._state === 'closed') {141        const destClosed = new TypeError('the destination writable stream closed before all data could be piped to it');142        if (preventCancel === false) {143          shutdownWithAction(() => ReadableStreamCancel(this, destClosed), true, destClosed);144        } else {145          shutdown(true, destClosed);146        }147      }148      pipeLoop().catch(err => {149        currentWrite = Promise.resolve();150        rethrowAssertionErrorRejection(err);151      });152      function waitForWritesToFinish() {153        // Another write may have started while we were waiting on this currentWrite, so we have to be sure to wait154        // for that too.155        const oldCurrentWrite = currentWrite;156        return currentWrite.then(() => oldCurrentWrite !== currentWrite ? waitForWritesToFinish() : undefined);157      }158      function isOrBecomesErrored(stream, promise, action) {159        if (stream._state === 'errored') {160          action(stream._storedError);161        } else {162          promise.catch(action).catch(rethrowAssertionErrorRejection);163        }164      }165      function isOrBecomesClosed(stream, promise, action) {166        if (stream._state === 'closed') {167          action();168        } else {169          promise.then(action).catch(rethrowAssertionErrorRejection);170        }171      }172      function shutdownWithAction(action, originalIsError, originalError) {173        if (shuttingDown === true) {174          return;175        }176        shuttingDown = true;177        if (dest._state === 'writable' && WritableStreamCloseQueuedOrInFlight(dest) === false) {178          waitForWritesToFinish().then(doTheRest);179        } else {180          doTheRest();181        }182        function doTheRest() {183          action().then(184            () => finalize(originalIsError, originalError),185            newError => finalize(true, newError)186          )187          .catch(rethrowAssertionErrorRejection);188        }189      }190      function shutdown(isError, error) {191        if (shuttingDown === true) {192          return;193        }194        shuttingDown = true;195        if (dest._state === 'writable' && WritableStreamCloseQueuedOrInFlight(dest) === false) {196          waitForWritesToFinish().then(() => finalize(isError, error)).catch(rethrowAssertionErrorRejection);197        } else {198          finalize(isError, error);199        }200      }201      function finalize(isError, error) {202        WritableStreamDefaultWriterRelease(writer);203        ReadableStreamReaderGenericRelease(reader);204        if (isError) {205          reject(error);206        } else {207          resolve(undefined);208        }209      }210    });211  }212  tee() {213    if (IsReadableStream(this) === false) {214      throw streamBrandCheckException('tee');215    }216    const branches = ReadableStreamTee(this, false);217    return createArrayFromList(branches);218  }219}220module.exports = {221  ReadableStream,222  IsReadableStreamDisturbed,223  ReadableStreamDefaultControllerClose,224  ReadableStreamDefaultControllerEnqueue,225  ReadableStreamDefaultControllerError,226  ReadableStreamDefaultControllerGetDesiredSize227};228// Abstract operations for the ReadableStream.229function AcquireReadableStreamBYOBReader(stream) {230  return new ReadableStreamBYOBReader(stream);231}232function AcquireReadableStreamDefaultReader(stream) {233  return new ReadableStreamDefaultReader(stream);234}235function IsReadableStream(x) {236  if (!typeIsObject(x)) {237    return false;238  }239  if (!Object.prototype.hasOwnProperty.call(x, '_readableStreamController')) {240    return false;241  }242  return true;243}244function IsReadableStreamDisturbed(stream) {245  assert(IsReadableStream(stream) === true, 'IsReadableStreamDisturbed should only be used on known readable streams');246  return stream._disturbed;247}248function IsReadableStreamLocked(stream) {249  assert(IsReadableStream(stream) === true, 'IsReadableStreamLocked should only be used on known readable streams');250  if (stream._reader === undefined) {251    return false;252  }253  return true;254}255function ReadableStreamTee(stream, cloneForBranch2) {256  assert(IsReadableStream(stream) === true);257  assert(typeof cloneForBranch2 === 'boolean');258  const reader = AcquireReadableStreamDefaultReader(stream);259  const teeState = {260    closedOrErrored: false,261    canceled1: false,262    canceled2: false,263    reason1: undefined,264    reason2: undefined265  };266  teeState.promise = new Promise(resolve => {267    teeState._resolve = resolve;268  });269  const pull = create_ReadableStreamTeePullFunction();270  pull._reader = reader;271  pull._teeState = teeState;272  pull._cloneForBranch2 = cloneForBranch2;273  const cancel1 = create_ReadableStreamTeeBranch1CancelFunction();274  cancel1._stream = stream;275  cancel1._teeState = teeState;276  const cancel2 = create_ReadableStreamTeeBranch2CancelFunction();277  cancel2._stream = stream;278  cancel2._teeState = teeState;279  const underlyingSource1 = Object.create(Object.prototype);280  createDataProperty(underlyingSource1, 'pull', pull);281  createDataProperty(underlyingSource1, 'cancel', cancel1);282  const branch1Stream = new ReadableStream(underlyingSource1);283  const underlyingSource2 = Object.create(Object.prototype);284  createDataProperty(underlyingSource2, 'pull', pull);285  createDataProperty(underlyingSource2, 'cancel', cancel2);286  const branch2Stream = new ReadableStream(underlyingSource2);287  pull._branch1 = branch1Stream._readableStreamController;288  pull._branch2 = branch2Stream._readableStreamController;289  reader._closedPromise.catch(r => {290    if (teeState.closedOrErrored === true) {291      return;292    }293    ReadableStreamDefaultControllerError(pull._branch1, r);294    ReadableStreamDefaultControllerError(pull._branch2, r);295    teeState.closedOrErrored = true;296  });297  return [branch1Stream, branch2Stream];298}299function create_ReadableStreamTeePullFunction() {300  function f() {301    const { _reader: reader, _branch1: branch1, _branch2: branch2, _teeState: teeState/* ,302            _cloneForBranch2: cloneForBranch2*/ } = f;303    return ReadableStreamDefaultReaderRead(reader).then(result => {304      assert(typeIsObject(result));305      const value = result.value;306      const done = result.done;307      assert(typeof done === 'boolean');308      if (done === true && teeState.closedOrErrored === false) {309        if (teeState.canceled1 === false) {310          ReadableStreamDefaultControllerClose(branch1);311        }312        if (teeState.canceled2 === false) {313          ReadableStreamDefaultControllerClose(branch2);314        }315        teeState.closedOrErrored = true;316      }317      if (teeState.closedOrErrored === true) {318        return;319      }320      const value1 = value;321      const value2 = value;322      // There is no way to access the cloning code right now in the reference implementation.323      // If we add one then we'll need an implementation for serializable objects.324      // if (teeState.canceled2 === false && cloneForBranch2 === true) {325      //   value2 = StructuredDeserialize(StructuredSerialize(value2));326      // }327      if (teeState.canceled1 === false) {328        ReadableStreamDefaultControllerEnqueue(branch1, value1);329      }330      if (teeState.canceled2 === false) {331        ReadableStreamDefaultControllerEnqueue(branch2, value2);332      }333    });334  }335  return f;336}337function create_ReadableStreamTeeBranch1CancelFunction() {338  function f(reason) {339    const { _stream: stream, _teeState: teeState } = f;340    teeState.canceled1 = true;341    teeState.reason1 = reason;342    if (teeState.canceled2 === true) {343      const compositeReason = createArrayFromList([teeState.reason1, teeState.reason2]);344      const cancelResult = ReadableStreamCancel(stream, compositeReason);345      teeState._resolve(cancelResult);346    }347    return teeState.promise;348  }349  return f;350}351function create_ReadableStreamTeeBranch2CancelFunction() {352  function f(reason) {353    const { _stream: stream, _teeState: teeState } = f;354    teeState.canceled2 = true;355    teeState.reason2 = reason;356    if (teeState.canceled1 === true) {357      const compositeReason = createArrayFromList([teeState.reason1, teeState.reason2]);358      const cancelResult = ReadableStreamCancel(stream, compositeReason);359      teeState._resolve(cancelResult);360    }361    return teeState.promise;362  }363  return f;364}365// ReadableStream API exposed for controllers.366function ReadableStreamAddReadIntoRequest(stream) {367  assert(IsReadableStreamBYOBReader(stream._reader) === true);368  assert(stream._state === 'readable' || stream._state === 'closed');369  const promise = new Promise((resolve, reject) => {370    const readIntoRequest = {371      _resolve: resolve,372      _reject: reject373    };374    stream._reader._readIntoRequests.push(readIntoRequest);375  });376  return promise;377}378function ReadableStreamAddReadRequest(stream) {379  assert(IsReadableStreamDefaultReader(stream._reader) === true);380  assert(stream._state === 'readable');381  const promise = new Promise((resolve, reject) => {382    const readRequest = {383      _resolve: resolve,384      _reject: reject385    };386    stream._reader._readRequests.push(readRequest);387  });388  return promise;389}390function ReadableStreamCancel(stream, reason) {391  stream._disturbed = true;392  if (stream._state === 'closed') {393    return Promise.resolve(undefined);394  }395  if (stream._state === 'errored') {396    return Promise.reject(stream._storedError);397  }398  ReadableStreamClose(stream);399  const sourceCancelPromise = stream._readableStreamController[CancelSteps](reason);400  return sourceCancelPromise.then(() => undefined);401}402function ReadableStreamClose(stream) {403  assert(stream._state === 'readable');404  stream._state = 'closed';405  const reader = stream._reader;406  if (reader === undefined) {407    return undefined;408  }409  if (IsReadableStreamDefaultReader(reader) === true) {410    for (const { _resolve } of reader._readRequests) {411      _resolve(CreateIterResultObject(undefined, true));412    }413    reader._readRequests = [];414  }415  defaultReaderClosedPromiseResolve(reader);416  return undefined;417}418function ReadableStreamError(stream, e) {419  assert(IsReadableStream(stream) === true, 'stream must be ReadableStream');420  assert(stream._state === 'readable', 'state must be readable');421  stream._state = 'errored';422  stream._storedError = e;423  const reader = stream._reader;424  if (reader === undefined) {425    return undefined;426  }427  if (IsReadableStreamDefaultReader(reader) === true) {428    for (const readRequest of reader._readRequests) {429      readRequest._reject(e);430    }431    reader._readRequests = [];432  } else {433    assert(IsReadableStreamBYOBReader(reader), 'reader must be ReadableStreamBYOBReader');434    for (const readIntoRequest of reader._readIntoRequests) {435      readIntoRequest._reject(e);436    }437    reader._readIntoRequests = [];438  }439  defaultReaderClosedPromiseReject(reader, e);440  reader._closedPromise.catch(() => {});441}442function ReadableStreamFulfillReadIntoRequest(stream, chunk, done) {443  const reader = stream._reader;444  assert(reader._readIntoRequests.length > 0);445  const readIntoRequest = reader._readIntoRequests.shift();446  readIntoRequest._resolve(CreateIterResultObject(chunk, done));447}448function ReadableStreamFulfillReadRequest(stream, chunk, done) {449  const reader = stream._reader;450  assert(reader._readRequests.length > 0);451  const readRequest = reader._readRequests.shift();452  readRequest._resolve(CreateIterResultObject(chunk, done));453}454function ReadableStreamGetNumReadIntoRequests(stream) {455  return stream._reader._readIntoRequests.length;456}457function ReadableStreamGetNumReadRequests(stream) {458  return stream._reader._readRequests.length;459}460function ReadableStreamHasBYOBReader(stream) {461  const reader = stream._reader;462  if (reader === undefined) {463    return false;464  }465  if (IsReadableStreamBYOBReader(reader) === false) {466    return false;467  }468  return true;469}470function ReadableStreamHasDefaultReader(stream) {471  const reader = stream._reader;472  if (reader === undefined) {473    return false;474  }475  if (IsReadableStreamDefaultReader(reader) === false) {476    return false;477  }478  return true;479}480// Readers481class ReadableStreamDefaultReader {482  constructor(stream) {483    if (IsReadableStream(stream) === false) {484      throw new TypeError('ReadableStreamDefaultReader can only be constructed with a ReadableStream instance');485    }486    if (IsReadableStreamLocked(stream) === true) {487      throw new TypeError('This stream has already been locked for exclusive reading by another reader');488    }489    ReadableStreamReaderGenericInitialize(this, stream);490    this._readRequests = [];491  }492  get closed() {493    if (IsReadableStreamDefaultReader(this) === false) {494      return Promise.reject(defaultReaderBrandCheckException('closed'));495    }496    return this._closedPromise;497  }498  cancel(reason) {499    if (IsReadableStreamDefaultReader(this) === false) {500      return Promise.reject(defaultReaderBrandCheckException('cancel'));501    }502    if (this._ownerReadableStream === undefined) {503      return Promise.reject(readerLockException('cancel'));504    }505    return ReadableStreamReaderGenericCancel(this, reason);506  }507  read() {508    if (IsReadableStreamDefaultReader(this) === false) {509      return Promise.reject(defaultReaderBrandCheckException('read'));510    }511    if (this._ownerReadableStream === undefined) {512      return Promise.reject(readerLockException('read from'));513    }514    return ReadableStreamDefaultReaderRead(this);515  }516  releaseLock() {517    if (IsReadableStreamDefaultReader(this) === false) {518      throw defaultReaderBrandCheckException('releaseLock');519    }520    if (this._ownerReadableStream === undefined) {521      return;522    }523    if (this._readRequests.length > 0) {524      throw new TypeError('Tried to release a reader lock when that reader has pending read() calls un-settled');525    }526    ReadableStreamReaderGenericRelease(this);527  }528}529class ReadableStreamBYOBReader {530  constructor(stream) {531    if (!IsReadableStream(stream)) {532      throw new TypeError('ReadableStreamBYOBReader can only be constructed with a ReadableStream instance given a ' +533          'byte source');534    }535    if (IsReadableByteStreamController(stream._readableStreamController) === false) {536      throw new TypeError('Cannot construct a ReadableStreamBYOBReader for a stream not constructed with a byte ' +537          'source');538    }539    if (IsReadableStreamLocked(stream)) {540      throw new TypeError('This stream has already been locked for exclusive reading by another reader');541    }542    ReadableStreamReaderGenericInitialize(this, stream);543    this._readIntoRequests = [];544  }545  get closed() {546    if (!IsReadableStreamBYOBReader(this)) {547      return Promise.reject(byobReaderBrandCheckException('closed'));548    }549    return this._closedPromise;550  }551  cancel(reason) {552    if (!IsReadableStreamBYOBReader(this)) {553      return Promise.reject(byobReaderBrandCheckException('cancel'));554    }555    if (this._ownerReadableStream === undefined) {556      return Promise.reject(readerLockException('cancel'));557    }558    return ReadableStreamReaderGenericCancel(this, reason);559  }560  read(view) {561    if (!IsReadableStreamBYOBReader(this)) {562      return Promise.reject(byobReaderBrandCheckException('read'));563    }564    if (this._ownerReadableStream === undefined) {565      return Promise.reject(readerLockException('read from'));566    }567    if (!ArrayBuffer.isView(view)) {568      return Promise.reject(new TypeError('view must be an array buffer view'));569    }570    if (view.byteLength === 0) {571      return Promise.reject(new TypeError('view must have non-zero byteLength'));572    }573    return ReadableStreamBYOBReaderRead(this, view);574  }575  releaseLock() {576    if (!IsReadableStreamBYOBReader(this)) {577      throw byobReaderBrandCheckException('releaseLock');578    }579    if (this._ownerReadableStream === undefined) {580      return;581    }582    if (this._readIntoRequests.length > 0) {583      throw new TypeError('Tried to release a reader lock when that reader has pending read() calls un-settled');584    }585    ReadableStreamReaderGenericRelease(this);586  }587}588// Abstract operations for the readers.589function IsReadableStreamBYOBReader(x) {590  if (!typeIsObject(x)) {591    return false;592  }593  if (!Object.prototype.hasOwnProperty.call(x, '_readIntoRequests')) {594    return false;595  }596  return true;597}598function IsReadableStreamDefaultReader(x) {599  if (!typeIsObject(x)) {600    return false;601  }602  if (!Object.prototype.hasOwnProperty.call(x, '_readRequests')) {603    return false;604  }605  return true;606}607function ReadableStreamReaderGenericInitialize(reader, stream) {608  reader._ownerReadableStream = stream;609  stream._reader = reader;610  if (stream._state === 'readable') {611    defaultReaderClosedPromiseInitialize(reader);612  } else if (stream._state === 'closed') {613    defaultReaderClosedPromiseInitializeAsResolved(reader);614  } else {615    assert(stream._state === 'errored', 'state must be errored');616    defaultReaderClosedPromiseInitializeAsRejected(reader, stream._storedError);617    reader._closedPromise.catch(() => {});618  }619}620// A client of ReadableStreamDefaultReader and ReadableStreamBYOBReader may use these functions directly to bypass state621// check.622function ReadableStreamReaderGenericCancel(reader, reason) {623  const stream = reader._ownerReadableStream;624  assert(stream !== undefined);625  return ReadableStreamCancel(stream, reason);626}627function ReadableStreamReaderGenericRelease(reader) {628  assert(reader._ownerReadableStream !== undefined);629  assert(reader._ownerReadableStream._reader === reader);630  if (reader._ownerReadableStream._state === 'readable') {631    defaultReaderClosedPromiseReject(632        reader,633        new TypeError('Reader was released and can no longer be used to monitor the stream\'s closedness'));634  } else {635    defaultReaderClosedPromiseResetToRejected(636        reader,637        new TypeError('Reader was released and can no longer be used to monitor the stream\'s closedness'));638  }639  reader._closedPromise.catch(() => {});640  reader._ownerReadableStream._reader = undefined;641  reader._ownerReadableStream = undefined;642}643function ReadableStreamBYOBReaderRead(reader, view) {644  const stream = reader._ownerReadableStream;645  assert(stream !== undefined);646  stream._disturbed = true;647  if (stream._state === 'errored') {648    return Promise.reject(stream._storedError);649  }650  // Controllers must implement this.651  return ReadableByteStreamControllerPullInto(stream._readableStreamController, view);652}653function ReadableStreamDefaultReaderRead(reader) {654  const stream = reader._ownerReadableStream;655  assert(stream !== undefined);656  stream._disturbed = true;657  if (stream._state === 'closed') {658    return Promise.resolve(CreateIterResultObject(undefined, true));659  }660  if (stream._state === 'errored') {661    return Promise.reject(stream._storedError);662  }663  assert(stream._state === 'readable');664  return stream._readableStreamController[PullSteps]();665}666// Controllers667class ReadableStreamDefaultController {668  constructor(stream, underlyingSource, size, highWaterMark) {669    if (IsReadableStream(stream) === false) {670      throw new TypeError('ReadableStreamDefaultController can only be constructed with a ReadableStream instance');671    }672    if (stream._readableStreamController !== undefined) {673      throw new TypeError(674        'ReadableStreamDefaultController instances can only be created by the ReadableStream constructor');675    }676    this._controlledReadableStream = stream;677    this._underlyingSource = underlyingSource;678    // Need to set the slots so that the assert doesn't fire. In the spec the slots already exist implicitly.679    this._queue = undefined;680    this._queueTotalSize = undefined;681    ResetQueue(this);682    this._started = false;683    this._closeRequested = false;684    this._pullAgain = false;685    this._pulling = false;686    const normalizedStrategy = ValidateAndNormalizeQueuingStrategy(size, highWaterMark);687    this._strategySize = normalizedStrategy.size;688    this._strategyHWM = normalizedStrategy.highWaterMark;689    const controller = this;690    const startResult = InvokeOrNoop(underlyingSource, 'start', [this]);691    Promise.resolve(startResult).then(692      () => {693        controller._started = true;694        assert(controller._pulling === false);695        assert(controller._pullAgain === false);696        ReadableStreamDefaultControllerCallPullIfNeeded(controller);697      },698      r => {699        ReadableStreamDefaultControllerErrorIfNeeded(controller, r);700      }701    )702    .catch(rethrowAssertionErrorRejection);703  }704  get desiredSize() {705    if (IsReadableStreamDefaultController(this) === false) {706      throw defaultControllerBrandCheckException('desiredSize');707    }708    return ReadableStreamDefaultControllerGetDesiredSize(this);709  }710  close() {711    if (IsReadableStreamDefaultController(this) === false) {712      throw defaultControllerBrandCheckException('close');713    }714    if (this._closeRequested === true) {715      throw new TypeError('The stream has already been closed; do not close it again!');716    }717    const state = this._controlledReadableStream._state;718    if (state !== 'readable') {719      throw new TypeError(`The stream (in ${state} state) is not in the readable state and cannot be closed`);720    }721    ReadableStreamDefaultControllerClose(this);722  }723  enqueue(chunk) {724    if (IsReadableStreamDefaultController(this) === false) {725      throw defaultControllerBrandCheckException('enqueue');726    }727    if (this._closeRequested === true) {728      throw new TypeError('stream is closed or draining');729    }730    const state = this._controlledReadableStream._state;731    if (state !== 'readable') {732      throw new TypeError(`The stream (in ${state} state) is not in the readable state and cannot be enqueued to`);733    }734    return ReadableStreamDefaultControllerEnqueue(this, chunk);735  }736  error(e) {737    if (IsReadableStreamDefaultController(this) === false) {738      throw defaultControllerBrandCheckException('error');739    }740    const stream = this._controlledReadableStream;741    if (stream._state !== 'readable') {742      throw new TypeError(`The stream is ${stream._state} and so cannot be errored`);743    }744    ReadableStreamDefaultControllerError(this, e);745  }746  [CancelSteps](reason) {747    ResetQueue(this);748    return PromiseInvokeOrNoop(this._underlyingSource, 'cancel', [reason]);749  }750  [PullSteps]() {751    const stream = this._controlledReadableStream;752    if (this._queue.length > 0) {753      const chunk = DequeueValue(this);754      if (this._closeRequested === true && this._queue.length === 0) {755        ReadableStreamClose(stream);756      } else {757        ReadableStreamDefaultControllerCallPullIfNeeded(this);758      }759      return Promise.resolve(CreateIterResultObject(chunk, false));760    }761    const pendingPromise = ReadableStreamAddReadRequest(stream);762    ReadableStreamDefaultControllerCallPullIfNeeded(this);763    return pendingPromise;764  }765}766// Abstract operations for the ReadableStreamDefaultController.767function IsReadableStreamDefaultController(x) {768  if (!typeIsObject(x)) {769    return false;770  }771  if (!Object.prototype.hasOwnProperty.call(x, '_underlyingSource')) {772    return false;773  }774  return true;775}776function ReadableStreamDefaultControllerCallPullIfNeeded(controller) {777  const shouldPull = ReadableStreamDefaultControllerShouldCallPull(controller);778  if (shouldPull === false) {779    return undefined;780  }781  if (controller._pulling === true) {782    controller._pullAgain = true;783    return undefined;784  }785  assert(controller._pullAgain === false);786  controller._pulling = true;787  const pullPromise = PromiseInvokeOrNoop(controller._underlyingSource, 'pull', [controller]);788  pullPromise.then(789    () => {790      controller._pulling = false;791      if (controller._pullAgain === true) {792        controller._pullAgain = false;793        return ReadableStreamDefaultControllerCallPullIfNeeded(controller);794      }795      return undefined;796    },797    e => {798      ReadableStreamDefaultControllerErrorIfNeeded(controller, e);799    }800  )801  .catch(rethrowAssertionErrorRejection);802  return undefined;803}804function ReadableStreamDefaultControllerShouldCallPull(controller) {805  const stream = controller._controlledReadableStream;806  if (stream._state === 'closed' || stream._state === 'errored') {807    return false;808  }809  if (controller._closeRequested === true) {810    return false;811  }812  if (controller._started === false) {813    return false;814  }815  if (IsReadableStreamLocked(stream) === true && ReadableStreamGetNumReadRequests(stream) > 0) {816    return true;817  }818  const desiredSize = ReadableStreamDefaultControllerGetDesiredSize(controller);819  if (desiredSize > 0) {820    return true;821  }822  return false;823}824// A client of ReadableStreamDefaultController may use these functions directly to bypass state check.825function ReadableStreamDefaultControllerClose(controller) {826  const stream = controller._controlledReadableStream;827  assert(controller._closeRequested === false);828  assert(stream._state === 'readable');829  controller._closeRequested = true;830  if (controller._queue.length === 0) {831    ReadableStreamClose(stream);832  }833}834function ReadableStreamDefaultControllerEnqueue(controller, chunk) {835  const stream = controller._controlledReadableStream;836  assert(controller._closeRequested === false);837  assert(stream._state === 'readable');838  if (IsReadableStreamLocked(stream) === true && ReadableStreamGetNumReadRequests(stream) > 0) {839    ReadableStreamFulfillReadRequest(stream, chunk, false);840  } else {841    let chunkSize = 1;842    if (controller._strategySize !== undefined) {843      const strategySize = controller._strategySize;844      try {845        chunkSize = strategySize(chunk);846      } catch (chunkSizeE) {847        ReadableStreamDefaultControllerErrorIfNeeded(controller, chunkSizeE);848        throw chunkSizeE;849      }850    }851    try {852      EnqueueValueWithSize(controller, chunk, chunkSize);853    } catch (enqueueE) {854      ReadableStreamDefaultControllerErrorIfNeeded(controller, enqueueE);855      throw enqueueE;856    }857  }858  ReadableStreamDefaultControllerCallPullIfNeeded(controller);859  return undefined;860}861function ReadableStreamDefaultControllerError(controller, e) {862  const stream = controller._controlledReadableStream;863  assert(stream._state === 'readable');864  ResetQueue(controller);865  ReadableStreamError(stream, e);866}867function ReadableStreamDefaultControllerErrorIfNeeded(controller, e) {868  if (controller._controlledReadableStream._state === 'readable') {869    ReadableStreamDefaultControllerError(controller, e);870  }871}872function ReadableStreamDefaultControllerGetDesiredSize(controller) {873  const stream = controller._controlledReadableStream;874  const state = stream._state;875  if (state === 'errored') {876    return null;877  }878  if (state === 'closed') {879    return 0;880  }881  return controller._strategyHWM - controller._queueTotalSize;882}883class ReadableStreamBYOBRequest {884  constructor(controller, view) {885    this._associatedReadableByteStreamController = controller;886    this._view = view;887  }888  get view() {889    return this._view;890  }891  respond(bytesWritten) {892    if (IsReadableStreamBYOBRequest(this) === false) {893      throw byobRequestBrandCheckException('respond');894    }895    if (this._associatedReadableByteStreamController === undefined) {896      throw new TypeError('This BYOB request has been invalidated');897    }898    ReadableByteStreamControllerRespond(this._associatedReadableByteStreamController, bytesWritten);899  }900  respondWithNewView(view) {901    if (IsReadableStreamBYOBRequest(this) === false) {902      throw byobRequestBrandCheckException('respond');903    }904    if (this._associatedReadableByteStreamController === undefined) {905      throw new TypeError('This BYOB request has been invalidated');906    }907    if (!ArrayBuffer.isView(view)) {908      throw new TypeError('You can only respond with array buffer views');909    }910    ReadableByteStreamControllerRespondWithNewView(this._associatedReadableByteStreamController, view);911  }912}913class ReadableByteStreamController {914  constructor(stream, underlyingByteSource, highWaterMark) {915    if (IsReadableStream(stream) === false) {916      throw new TypeError('ReadableByteStreamController can only be constructed with a ReadableStream instance given ' +917          'a byte source');918    }919    if (stream._readableStreamController !== undefined) {920      throw new TypeError(921          'ReadableByteStreamController instances can only be created by the ReadableStream constructor given a byte ' +922              'source');923    }924    this._controlledReadableStream = stream;925    this._underlyingByteSource = underlyingByteSource;926    this._pullAgain = false;927    this._pulling = false;928    ReadableByteStreamControllerClearPendingPullIntos(this);929    // Need to set the slots so that the assert doesn't fire. In the spec the slots already exist implicitly.930    this._queue = this._queueTotalSize = undefined;931    ResetQueue(this);932    this._closeRequested = false;933    this._started = false;934    this._strategyHWM = ValidateAndNormalizeHighWaterMark(highWaterMark);935    const autoAllocateChunkSize = underlyingByteSource.autoAllocateChunkSize;936    if (autoAllocateChunkSize !== undefined) {937      if (Number.isInteger(autoAllocateChunkSize) === false || autoAllocateChunkSize <= 0) {938        throw new RangeError('autoAllocateChunkSize must be a positive integer');939      }940    }941    this._autoAllocateChunkSize = autoAllocateChunkSize;942    this._pendingPullIntos = [];943    const controller = this;944    const startResult = InvokeOrNoop(underlyingByteSource, 'start', [this]);945    Promise.resolve(startResult).then(946      () => {947        controller._started = true;948        assert(controller._pulling === false);949        assert(controller._pullAgain === false);950        ReadableByteStreamControllerCallPullIfNeeded(controller);951      },952      r => {953        if (stream._state === 'readable') {954          ReadableByteStreamControllerError(controller, r);955        }956      }957    )958    .catch(rethrowAssertionErrorRejection);959  }960  get byobRequest() {961    if (IsReadableByteStreamController(this) === false) {962      throw byteStreamControllerBrandCheckException('byobRequest');963    }964    if (this._byobRequest === undefined && this._pendingPullIntos.length > 0) {965      const firstDescriptor = this._pendingPullIntos[0];966      const view = new Uint8Array(firstDescriptor.buffer,967                                  firstDescriptor.byteOffset + firstDescriptor.bytesFilled,968                                  firstDescriptor.byteLength - firstDescriptor.bytesFilled);969      this._byobRequest = new ReadableStreamBYOBRequest(this, view);970    }971    return this._byobRequest;972  }973  get desiredSize() {974    if (IsReadableByteStreamController(this) === false) {975      throw byteStreamControllerBrandCheckException('desiredSize');976    }977    return ReadableByteStreamControllerGetDesiredSize(this);978  }979  close() {980    if (IsReadableByteStreamController(this) === false) {981      throw byteStreamControllerBrandCheckException('close');982    }983    if (this._closeRequested === true) {984      throw new TypeError('The stream has already been closed; do not close it again!');985    }986    const state = this._controlledReadableStream._state;987    if (state !== 'readable') {988      throw new TypeError(`The stream (in ${state} state) is not in the readable state and cannot be closed`);989    }990    ReadableByteStreamControllerClose(this);991  }992  enqueue(chunk) {993    if (IsReadableByteStreamController(this) === false) {994      throw byteStreamControllerBrandCheckException('enqueue');995    }996    if (this._closeRequested === true) {997      throw new TypeError('stream is closed or draining');998    }999    const state = this._controlledReadableStream._state;1000    if (state !== 'readable') {1001      throw new TypeError(`The stream (in ${state} state) is not in the readable state and cannot be enqueued to`);1002    }1003    if (!ArrayBuffer.isView(chunk)) {1004      throw new TypeError('You can only enqueue array buffer views when using a ReadableByteStreamController');1005    }1006    ReadableByteStreamControllerEnqueue(this, chunk);1007  }1008  error(e) {1009    if (IsReadableByteStreamController(this) === false) {1010      throw byteStreamControllerBrandCheckException('error');1011    }1012    const stream = this._controlledReadableStream;1013    if (stream._state !== 'readable') {1014      throw new TypeError(`The stream is ${stream._state} and so cannot be errored`);1015    }1016    ReadableByteStreamControllerError(this, e);1017  }1018  [CancelSteps](reason) {1019    if (this._pendingPullIntos.length > 0) {1020      const firstDescriptor = this._pendingPullIntos[0];1021      firstDescriptor.bytesFilled = 0;1022    }1023    ResetQueue(this);1024    return PromiseInvokeOrNoop(this._underlyingByteSource, 'cancel', [reason]);1025  }1026  [PullSteps]() {1027    const stream = this._controlledReadableStream;1028    assert(ReadableStreamHasDefaultReader(stream) === true);1029    if (this._queueTotalSize > 0) {1030      assert(ReadableStreamGetNumReadRequests(stream) === 0);1031      const entry = this._queue.shift();1032      this._queueTotalSize -= entry.byteLength;1033      ReadableByteStreamControllerHandleQueueDrain(this);1034      let view;1035      try {1036        view = new Uint8Array(entry.buffer, entry.byteOffset, entry.byteLength);1037      } catch (viewE) {1038        return Promise.reject(viewE);1039      }1040      return Promise.resolve(CreateIterResultObject(view, false));1041    }1042    const autoAllocateChunkSize = this._autoAllocateChunkSize;1043    if (autoAllocateChunkSize !== undefined) {1044      let buffer;1045      try {1046        buffer = new ArrayBuffer(autoAllocateChunkSize);1047      } catch (bufferE) {1048        return Promise.reject(bufferE);1049      }1050      const pullIntoDescriptor = {1051        buffer,1052        byteOffset: 0,1053        byteLength: autoAllocateChunkSize,1054        bytesFilled: 0,1055        elementSize: 1,1056        ctor: Uint8Array,1057        readerType: 'default'1058      };1059      this._pendingPullIntos.push(pullIntoDescriptor);1060    }1061    const promise = ReadableStreamAddReadRequest(stream);1062    ReadableByteStreamControllerCallPullIfNeeded(this);1063    return promise;1064  }1065}1066// Abstract operations for the ReadableByteStreamController.1067function IsReadableByteStreamController(x) {1068  if (!typeIsObject(x)) {1069    return false;1070  }1071  if (!Object.prototype.hasOwnProperty.call(x, '_underlyingByteSource')) {1072    return false;1073  }1074  return true;1075}1076function IsReadableStreamBYOBRequest(x) {1077  if (!typeIsObject(x)) {1078    return false;1079  }1080  if (!Object.prototype.hasOwnProperty.call(x, '_associatedReadableByteStreamController')) {1081    return false;1082  }1083  return true;1084}1085function ReadableByteStreamControllerCallPullIfNeeded(controller) {1086  const shouldPull = ReadableByteStreamControllerShouldCallPull(controller);1087  if (shouldPull === false) {1088    return undefined;1089  }1090  if (controller._pulling === true) {1091    controller._pullAgain = true;1092    return undefined;1093  }1094  assert(controller._pullAgain === false);1095  controller._pulling = true;1096  // TODO: Test controller argument1097  const pullPromise = PromiseInvokeOrNoop(controller._underlyingByteSource, 'pull', [controller]);1098  pullPromise.then(1099    () => {1100      controller._pulling = false;1101      if (controller._pullAgain === true) {1102        controller._pullAgain = false;1103        ReadableByteStreamControllerCallPullIfNeeded(controller);1104      }1105    },1106    e => {1107      if (controller._controlledReadableStream._state === 'readable') {1108        ReadableByteStreamControllerError(controller, e);1109      }1110    }1111  )1112  .catch(rethrowAssertionErrorRejection);1113  return undefined;1114}1115function ReadableByteStreamControllerClearPendingPullIntos(controller) {1116  ReadableByteStreamControllerInvalidateBYOBRequest(controller);1117  controller._pendingPullIntos = [];1118}1119function ReadableByteStreamControllerCommitPullIntoDescriptor(stream, pullIntoDescriptor) {1120  assert(stream._state !== 'errored', 'state must not be errored');1121  let done = false;1122  if (stream._state === 'closed') {1123    assert(pullIntoDescriptor.bytesFilled === 0);1124    done = true;1125  }1126  const filledView = ReadableByteStreamControllerConvertPullIntoDescriptor(pullIntoDescriptor);1127  if (pullIntoDescriptor.readerType === 'default') {1128    ReadableStreamFulfillReadRequest(stream, filledView, done);1129  } else {1130    assert(pullIntoDescriptor.readerType === 'byob');1131    ReadableStreamFulfillReadIntoRequest(stream, filledView, done);1132  }1133}1134function ReadableByteStreamControllerConvertPullIntoDescriptor(pullIntoDescriptor) {1135  const bytesFilled = pullIntoDescriptor.bytesFilled;1136  const elementSize = pullIntoDescriptor.elementSize;1137  assert(bytesFilled <= pullIntoDescriptor.byteLength);1138  assert(bytesFilled % elementSize === 0);1139  return new pullIntoDescriptor.ctor(1140      pullIntoDescriptor.buffer, pullIntoDescriptor.byteOffset, bytesFilled / elementSize);1141}1142function ReadableByteStreamControllerEnqueueChunkToQueue(controller, buffer, byteOffset, byteLength) {1143  controller._queue.push({ buffer, byteOffset, byteLength });1144  controller._queueTotalSize += byteLength;1145}1146function ReadableByteStreamControllerFillPullIntoDescriptorFromQueue(controller, pullIntoDescriptor) {1147  const elementSize = pullIntoDescriptor.elementSize;1148  const currentAlignedBytes = pullIntoDescriptor.bytesFilled - pullIntoDescriptor.bytesFilled % elementSize;1149  const maxBytesToCopy = Math.min(controller._queueTotalSize,1150                                  pullIntoDescriptor.byteLength - pullIntoDescriptor.bytesFilled);1151  const maxBytesFilled = pullIntoDescriptor.bytesFilled + maxBytesToCopy;1152  const maxAlignedBytes = maxBytesFilled - maxBytesFilled % elementSize;1153  let totalBytesToCopyRemaining = maxBytesToCopy;1154  let ready = false;1155  if (maxAlignedBytes > currentAlignedBytes) {1156    totalBytesToCopyRemaining = maxAlignedBytes - pullIntoDescriptor.bytesFilled;1157    ready = true;1158  }1159  const queue = controller._queue;1160  while (totalBytesToCopyRemaining > 0) {1161    const headOfQueue = queue[0];1162    const bytesToCopy = Math.min(totalBytesToCopyRemaining, headOfQueue.byteLength);1163    const destStart = pullIntoDescriptor.byteOffset + pullIntoDescriptor.bytesFilled;1164    ArrayBufferCopy(pullIntoDescriptor.buffer, destStart, headOfQueue.buffer, headOfQueue.byteOffset, bytesToCopy);1165    if (headOfQueue.byteLength === bytesToCopy) {1166      queue.shift();1167    } else {1168      headOfQueue.byteOffset += bytesToCopy;1169      headOfQueue.byteLength -= bytesToCopy;1170    }1171    controller._queueTotalSize -= bytesToCopy;1172    ReadableByteStreamControllerFillHeadPullIntoDescriptor(controller, bytesToCopy, pullIntoDescriptor);1173    totalBytesToCopyRemaining -= bytesToCopy;1174  }1175  if (ready === false) {1176    assert(controller._queueTotalSize === 0, 'queue must be empty');1177    assert(pullIntoDescriptor.bytesFilled > 0);1178    assert(pullIntoDescriptor.bytesFilled < pullIntoDescriptor.elementSize);1179  }1180  return ready;1181}1182function ReadableByteStreamControllerFillHeadPullIntoDescriptor(controller, size, pullIntoDescriptor) {1183  assert(controller._pendingPullIntos.length === 0 || controller._pendingPullIntos[0] === pullIntoDescriptor);1184  ReadableByteStreamControllerInvalidateBYOBRequest(controller);1185  pullIntoDescriptor.bytesFilled += size;1186}1187function ReadableByteStreamControllerHandleQueueDrain(controller) {1188  assert(controller._controlledReadableStream._state === 'readable');1189  if (controller._queueTotalSize === 0 && controller._closeRequested === true) {1190    ReadableStreamClose(controller._controlledReadableStream);1191  } else {1192    ReadableByteStreamControllerCallPullIfNeeded(controller);1193  }1194}1195function ReadableByteStreamControllerInvalidateBYOBRequest(controller) {1196  if (controller._byobRequest === undefined) {1197    return;1198  }1199  controller._byobRequest._associatedReadableByteStreamController = undefined;1200  controller._byobRequest._view = undefined;1201  controller._byobRequest = undefined;1202}1203function ReadableByteStreamControllerProcessPullIntoDescriptorsUsingQueue(controller) {1204  assert(controller._closeRequested === false);1205  while (controller._pendingPullIntos.length > 0) {1206    if (controller._queueTotalSize === 0) {1207      return;1208    }1209    const pullIntoDescriptor = controller._pendingPullIntos[0];1210    if (ReadableByteStreamControllerFillPullIntoDescriptorFromQueue(controller, pullIntoDescriptor) === true) {1211      ReadableByteStreamControllerShiftPendingPullInto(controller);1212      ReadableByteStreamControllerCommitPullIntoDescriptor(controller._controlledReadableStream, pullIntoDescriptor);1213    }1214  }1215}1216function ReadableByteStreamControllerPullInto(controller, view) {1217  const stream = controller._controlledReadableStream;1218  let elementSize = 1;1219  if (view.constructor !== DataView) {1220    elementSize = view.constructor.BYTES_PER_ELEMENT;1221  }1222  const ctor = view.constructor;1223  const pullIntoDescriptor = {1224    buffer: view.buffer,1225    byteOffset: view.byteOffset,1226    byteLength: view.byteLength,1227    bytesFilled: 0,1228    elementSize,1229    ctor,1230    readerType: 'byob'1231  };1232  if (controller._pendingPullIntos.length > 0) {1233    pullIntoDescriptor.buffer = TransferArrayBuffer(pullIntoDescriptor.buffer);1234    controller._pendingPullIntos.push(pullIntoDescriptor);1235    // No ReadableByteStreamControllerCallPullIfNeeded() call since:1236    // - No change happens on desiredSize1237    // - The source has already been notified of that there's at least 1 pending read(view)1238    return ReadableStreamAddReadIntoRequest(stream);1239  }1240  if (stream._state === 'closed') {1241    const emptyView = new view.constructor(pullIntoDescriptor.buffer, pullIntoDescriptor.byteOffset, 0);1242    return Promise.resolve(CreateIterResultObject(emptyView, true));1243  }1244  if (controller._queueTotalSize > 0) {1245    if (ReadableByteStreamControllerFillPullIntoDescriptorFromQueue(controller, pullIntoDescriptor) === true) {1246      const filledView = ReadableByteStreamControllerConvertPullIntoDescriptor(pullIntoDescriptor);1247      ReadableByteStreamControllerHandleQueueDrain(controller);1248      return Promise.resolve(CreateIterResultObject(filledView, false));1249    }1250    if (controller._closeRequested === true) {1251      const e = new TypeError('Insufficient bytes to fill elements in the given buffer');1252      ReadableByteStreamControllerError(controller, e);1253      return Promise.reject(e);1254    }1255  }1256  pullIntoDescriptor.buffer = TransferArrayBuffer(pullIntoDescriptor.buffer);1257  controller._pendingPullIntos.push(pullIntoDescriptor);1258  const promise = ReadableStreamAddReadIntoRequest(stream);1259  ReadableByteStreamControllerCallPullIfNeeded(controller);1260  return promise;1261}1262function ReadableByteStreamControllerRespondInClosedState(controller, firstDescriptor) {1263  firstDescriptor.buffer = TransferArrayBuffer(firstDescriptor.buffer);1264  assert(firstDescriptor.bytesFilled === 0, 'bytesFilled must be 0');1265  const stream = controller._controlledReadableStream;1266  if (ReadableStreamHasBYOBReader(stream) === true) {1267    while (ReadableStreamGetNumReadIntoRequests(stream) > 0) {1268      const pullIntoDescriptor = ReadableByteStreamControllerShiftPendingPullInto(controller);1269      ReadableByteStreamControllerCommitPullIntoDescriptor(stream, pullIntoDescriptor);1270    }1271  }1272}1273function ReadableByteStreamControllerRespondInReadableState(controller, bytesWritten, pullIntoDescriptor) {1274  if (pullIntoDescriptor.bytesFilled + bytesWritten > pullIntoDescriptor.byteLength) {1275    throw new RangeError('bytesWritten out of range');1276  }1277  ReadableByteStreamControllerFillHeadPullIntoDescriptor(controller, bytesWritten, pullIntoDescriptor);1278  if (pullIntoDescriptor.bytesFilled < pullIntoDescriptor.elementSize) {1279    // TODO: Figure out whether we should detach the buffer or not here.1280    return;1281  }1282  ReadableByteStreamControllerShiftPendingPullInto(controller);1283  const remainderSize = pullIntoDescriptor.bytesFilled % pullIntoDescriptor.elementSize;1284  if (remainderSize > 0) {1285    const end = pullIntoDescriptor.byteOffset + pullIntoDescriptor.bytesFilled;1286    const remainder = pullIntoDescriptor.buffer.slice(end - remainderSize, end);1287    ReadableByteStreamControllerEnqueueChunkToQueue(controller, remainder, 0, remainder.byteLength);1288  }1289  pullIntoDescriptor.buffer = TransferArrayBuffer(pullIntoDescriptor.buffer);1290  pullIntoDescriptor.bytesFilled -= remainderSize;1291  ReadableByteStreamControllerCommitPullIntoDescriptor(controller._controlledReadableStream, pullIntoDescriptor);1292  ReadableByteStreamControllerProcessPullIntoDescriptorsUsingQueue(controller);1293}1294function ReadableByteStreamControllerRespondInternal(controller, bytesWritten) {1295  const firstDescriptor = controller._pendingPullIntos[0];1296  const stream = controller._controlledReadableStream;1297  if (stream._state === 'closed') {1298    if (bytesWritten !== 0) {1299      throw new TypeError('bytesWritten must be 0 when calling respond() on a closed stream');1300    }1301    ReadableByteStreamControllerRespondInClosedState(controller, firstDescriptor);1302  } else {1303    assert(stream._state === 'readable');1304    ReadableByteStreamControllerRespondInReadableState(controller, bytesWritten, firstDescriptor);1305  }1306}1307function ReadableByteStreamControllerShiftPendingPullInto(controller) {1308  const descriptor = controller._pendingPullIntos.shift();1309  ReadableByteStreamControllerInvalidateBYOBRequest(controller);1310  return descriptor;1311}1312function ReadableByteStreamControllerShouldCallPull(controller) {1313  const stream = controller._controlledReadableStream;1314  if (stream._state !== 'readable') {1315    return false;1316  }1317  if (controller._closeRequested === true) {1318    return false;1319  }1320  if (controller._started === false) {1321    return false;1322  }1323  if (ReadableStreamHasDefaultReader(stream) === true && ReadableStreamGetNumReadRequests(stream) > 0) {1324    return true;1325  }1326  if (ReadableStreamHasBYOBReader(stream) === true && ReadableStreamGetNumReadIntoRequests(stream) > 0) {1327    return true;1328  }1329  if (ReadableByteStreamControllerGetDesiredSize(controller) > 0) {1330    return true;1331  }1332  return false;1333}1334// A client of ReadableByteStreamController may use these functions directly to bypass state check.1335function ReadableByteStreamControllerClose(controller) {1336  const stream = controller._controlledReadableStream;1337  assert(controller._closeRequested === false);1338  assert(stream._state === 'readable');1339  if (controller._queueTotalSize > 0) {1340    controller._closeRequested = true;1341    return;1342  }1343  if (controller._pendingPullIntos.length > 0) {1344    const firstPendingPullInto = controller._pendingPullIntos[0];1345    if (firstPendingPullInto.bytesFilled > 0) {1346      const e = new TypeError('Insufficient bytes to fill elements in the given buffer');1347      ReadableByteStreamControllerError(controller, e);1348      throw e;1349    }1350  }1351  ReadableStreamClose(stream);1352}1353function ReadableByteStreamControllerEnqueue(controller, chunk) {1354  const stream = controller._controlledReadableStream;1355  assert(controller._closeRequested === false);1356  assert(stream._state === 'readable');1357  const buffer = chunk.buffer;1358  const byteOffset = chunk.byteOffset;1359  const byteLength = chunk.byteLength;1360  const transferredBuffer = TransferArrayBuffer(buffer);1361  if (ReadableStreamHasDefaultReader(stream) === true) {1362    if (ReadableStreamGetNumReadRequests(stream) === 0) {1363      ReadableByteStreamControllerEnqueueChunkToQueue(controller, transferredBuffer, byteOffset, byteLength);1364    } else {1365      assert(controller._queue.length === 0);1366      const transferredView = new Uint8Array(transferredBuffer, byteOffset, byteLength);1367      ReadableStreamFulfillReadRequest(stream, transferredView, false);1368    }1369  } else if (ReadableStreamHasBYOBReader(stream) === true) {1370    // TODO: Ideally in this branch detaching should happen only if the buffer is not consumed fully.1371    ReadableByteStreamControllerEnqueueChunkToQueue(controller, transferredBuffer, byteOffset, byteLength);1372    ReadableByteStreamControllerProcessPullIntoDescriptorsUsingQueue(controller);1373  } else {1374    assert(IsReadableStreamLocked(stream) === false, 'stream must not be locked');1375    ReadableByteStreamControllerEnqueueChunkToQueue(controller, transferredBuffer, byteOffset, byteLength);1376  }1377}1378function ReadableByteStreamControllerError(controller, e) {1379  const stream = controller._controlledReadableStream;1380  assert(stream._state === 'readable');1381  ReadableByteStreamControllerClearPendingPullIntos(controller);1382  ResetQueue(controller);1383  ReadableStreamError(stream, e);1384}1385function ReadableByteStreamControllerGetDesiredSize(controller) {1386  const stream = controller._controlledReadableStream;1387  const state = stream._state;1388  if (state === 'errored') {1389    return null;1390  }1391  if (state === 'closed') {1392    return 0;1393  }1394  return controller._strategyHWM - controller._queueTotalSize;1395}1396function ReadableByteStreamControllerRespond(controller, bytesWritten) {1397  bytesWritten = Number(bytesWritten);1398  if (IsFiniteNonNegativeNumber(bytesWritten) === false) {1399    throw new RangeError('bytesWritten must be a finite');1400  }1401  assert(controller._pendingPullIntos.length > 0);1402  ReadableByteStreamControllerRespondInternal(controller, bytesWritten);1403}1404function ReadableByteStreamControllerRespondWithNewView(controller, view) {1405  assert(controller._pendingPullIntos.length > 0);1406  const firstDescriptor = controller._pendingPullIntos[0];1407  if (firstDescriptor.byteOffset + firstDescriptor.bytesFilled !== view.byteOffset) {1408    throw new RangeError('The region specified by view does not match byobRequest');1409  }1410  if (firstDescriptor.byteLength !== view.byteLength) {1411    throw new RangeError('The buffer of view has different capacity than byobRequest');1412  }1413  firstDescriptor.buffer = view.buffer;1414  ReadableByteStreamControllerRespondInternal(controller, view.byteLength);1415}1416// Helper functions for the ReadableStream.1417function streamBrandCheckException(name) {1418  return new TypeError(`ReadableStream.prototype.${name} can only be used on a ReadableStream`);1419}1420// Helper functions for the readers.1421function readerLockException(name) {1422  return new TypeError('Cannot ' + name + ' a stream using a released reader');1423}1424// Helper functions for the ReadableStreamDefaultReader.1425function defaultReaderBrandCheckException(name) {1426  return new TypeError(1427    `ReadableStreamDefaultReader.prototype.${name} can only be used on a ReadableStreamDefaultReader`);1428}1429function defaultReaderClosedPromiseInitialize(reader) {1430  reader._closedPromise = new Promise((resolve, reject) => {1431    reader._closedPromise_resolve = resolve;1432    reader._closedPromise_reject = reject;1433  });1434}1435function defaultReaderClosedPromiseInitializeAsRejected(reader, reason) {1436  reader._closedPromise = Promise.reject(reason);1437  reader._closedPromise_resolve = undefined;1438  reader._closedPromise_reject = undefined;1439}1440function defaultReaderClosedPromiseInitializeAsResolved(reader) {1441  reader._closedPromise = Promise.resolve(undefined);1442  reader._closedPromise_resolve = undefined;1443  reader._closedPromise_reject = undefined;1444}1445function defaultReaderClosedPromiseReject(reader, reason) {1446  assert(reader._closedPromise_resolve !== undefined);1447  assert(reader._closedPromise_reject !== undefined);1448  reader._closedPromise_reject(reason);1449  reader._closedPromise_resolve = undefined;1450  reader._closedPromise_reject = undefined;1451}1452function defaultReaderClosedPromiseResetToRejected(reader, reason) {1453  assert(reader._closedPromise_resolve === undefined);1454  assert(reader._closedPromise_reject === undefined);1455  reader._closedPromise = Promise.reject(reason);1456}1457function defaultReaderClosedPromiseResolve(reader) {1458  assert(reader._closedPromise_resolve !== undefined);1459  assert(reader._closedPromise_reject !== undefined);1460  reader._closedPromise_resolve(undefined);1461  reader._closedPromise_resolve = undefined;1462  reader._closedPromise_reject = undefined;1463}1464// Helper functions for the ReadableStreamDefaultReader.1465function byobReaderBrandCheckException(name) {1466  return new TypeError(1467    `ReadableStreamBYOBReader.prototype.${name} can only be used on a ReadableStreamBYOBReader`);1468}1469// Helper functions for the ReadableStreamDefaultController.1470function defaultControllerBrandCheckException(name) {1471  return new TypeError(1472    `ReadableStreamDefaultController.prototype.${name} can only be used on a ReadableStreamDefaultController`);1473}1474// Helper functions for the ReadableStreamBYOBRequest.1475function byobRequestBrandCheckException(name) {1476  return new TypeError(1477    `ReadableStreamBYOBRequest.prototype.${name} can only be used on a ReadableStreamBYOBRequest`);1478}1479// Helper functions for the ReadableByteStreamController.1480function byteStreamControllerBrandCheckException(name) {1481  return new TypeError(1482    `ReadableByteStreamController.prototype.${name} can only be used on a ReadableByteStreamController`);1483}1484// Helper function for ReadableStream pipeThrough1485function ifIsObjectAndHasAPromiseIsHandledInternalSlotSetPromiseIsHandledToTrue(promise) {1486  try {1487    // This relies on the brand-check that is enforced by Promise.prototype.then(). As with the rest of the reference1488    // implementation, it doesn't attempt to do the right thing if someone has modified the global environment.1489    Promise.prototype.then.call(promise, undefined, () => {});1490  } catch (e) {1491    // The brand check failed, therefore the internal slot is not present and there's nothing further to do.1492  }...

Using AI Code Generation

1var harness = $262.createRealm().global;2var ifIsObjectAndHasAPromiseIsHandledInternalSlotSetPromiseIsHandledToTrue = harness.ifIsObjectAndHasAPromiseIsHandledInternalSlotSetPromiseIsHandledToTrue;3var p = new Promise(function(resolve, reject) {4  resolve(1);5});6p.then(function() {});7ifIsObjectAndHasAPromiseIsHandledInternalSlotSetPromiseIsHandledToTrue(p);8var harness = $262.createRealm().global;9var ifIsObjectAndHasAPromiseIsHandledInternalSlotSetPromiseIsHandledToTrue = harness.ifIsObjectAndHasAPromiseIsHandledInternalSlotSetPromiseIsHandledToTrue;10var p = new Promise(function(resolve, reject) {11  resolve(1);12});13p.then(function() {});14ifIsObjectAndHasAPromiseIsHandledInternalSlotSetPromiseIsHandledToTrue(p);15var harness = $262.createRealm().global;16var ifIsObjectAndHasAPromiseIsHandledInternalSlotSetPromiseIsHandledToTrue = harness.ifIsObjectAndHasAPromiseIsHandledInternalSlotSetPromiseIsHandledToTrue;17var p = new Promise(function(resolve, reject) {18  resolve(1);19});20p.then(function() {});21ifIsObjectAndHasAPromiseIsHandledInternalSlotSetPromiseIsHandledToTrue(p);22var harness = $262.createRealm().global;23var ifIsObjectAndHasAPromiseIsHandledInternalSlotSetPromiseIsHandledToTrue = harness.ifIsObjectAndHasAPromiseIsHandledInternalSlotSetPromiseIsHandledToTrue;

Using AI Code Generation

1var harness = $262.harness;2var ifIsObjectAndHasAPromiseIsHandledInternalSlotSetPromiseIsHandledToTrue = harness.ifIsObjectAndHasAPromiseIsHandledInternalSlotSetPromiseIsHandledToTrue;3var p = Promise.resolve();4var p2 = Promise.reject();5ifIsObjectAndHasAPromiseIsHandledInternalSlotSetPromiseIsHandledToTrue(p);6ifIsObjectAndHasAPromiseIsHandledInternalSlotSetPromiseIsHandledToTrue(p2);7p.catch(function(){});8p2.catch(function(){});9var harness = $262.harness;10var ifIsObjectAndHasAPromiseIsHandledInternalSlotSetPromiseIsHandledToTrue = harness.ifIsObjectAndHasAPromiseIsHandledInternalSlotSetPromiseIsHandledToTrue;11var p = Promise.resolve();12ifIsObjectAndHasAPromiseIsHandledInternalSlotSetPromiseIsHandledToTrue(p);13p.catch(function(){});

Using AI Code Generation

1const { ifIsObjectAndHasAPromiseIsHandledInternalSlotSetPromiseIsHandledToTrue } = require('./harness/ifIsObjectAndHasAPromiseIsHandledInternalSlotSetPromiseIsHandledToTrue.js');2const { ifIsObjectAndHasAPromiseIsHandledInternalSlotSetPromiseIsHandledToFalse } = require('./harness/ifIsObjectAndHasAPromiseIsHandledInternalSlotSetPromiseIsHandledToFalse.js');3const { ifIsObjectAndHasAPromiseIsHandledInternalSlotThrow } = require('./harness/ifIsObjectAndHasAPromiseIsHandledInternalSlotThrow.js');4const { ifIsObjectAndHasAPromiseIsHandledInternalSlotReturn } = require('./harness/ifIsObjectAndHasAPromiseIsHandledInternalSlotReturn.js');5const { ifIsObjectAndHasAPromiseIsHandledInternalSlotReturnUndefined } = require('./harness/ifIsObjectAndHasAPromiseIsHandledInternalSlotReturnUndefined.js');6const { ifIsObjectAndHasAPromiseIsHandledInternalSlotReturnUndefined } = require('./harness/ifIsObjectAndHasAPromiseIsHandledInternalSlotReturnUndefined.js');7const { ifIsObjectAndHasAPromiseIsHandledInternalSlotReturnUndefined } = require('./harness/ifIsObjectAndHasAPromiseIsHandledInternalSlotReturnUndefined.js');8const { ifIsObjectAndHasAPromiseIsHandledInternalSlotReturnUndefined } = require('./harness/ifIsObjectAndHasAPromiseIsHandledInternalSlotReturnUndefined.js');9const { ifIsObjectAndHasAPromiseIsHandled

Using AI Code Generation

1const { ifIsObjectAndHasAPromiseIsHandledInternalSlotSetPromiseIsHandledToTrue } = require('./resources/testharness.js');2const { ifIsObjectAndHasAPromiseIsHandledInternalSlotSetPromiseIsHandledToTrue } = require('./resources/testharness.js');3const { ifIsObjectAndHasAPromiseIsHandledInternalSlotSetPromiseIsHandledToTrue } = require('./resources/testharness.js');4const { ifIsObjectAndHasAPromiseIsHandledInternalSlotSetPromiseIsHandledToTrue } = require('./resources/testharness.js');5const { ifIsObjectAndHasAPromiseIsHandledInternalSlotSetPromiseIsHandledToTrue } = require('./resources/testharness.js');6const { ifIsObjectAndHasAPromiseIsHandledInternalSlotSetPromiseIsHandledToTrue } = require('./resources/testharness.js');7const { ifIsObjectAndHasAPromiseIsHandledInternalSlotSetPromiseIsHandledToTrue } = require('./resources/testharness.js');8const { ifIsObjectAndHasAPromiseIsHandledInternalSlotSetPromiseIsHandledToTrue } = require('./resources/testharness.js');9const { ifIsObjectAndHasAPromiseIsHandledInternalSlotSetPromiseIsHandledToTrue } = require('./resources/testharness.js');

Using AI Code Generation

1const { ifIsObjectAndHasAPromiseIsHandledInternalSlotSetPromiseIsHandledToTrue } = WPTLib;2ifIsObjectAndHasAPromiseIsHandledInternalSlotSetPromiseIsHandledToTrue(promise);3const { ifIsObjectAndHasAPromiseIsHandledInternalSlotSetPromiseIsHandledToTrue } = WPTLib;4ifIsObjectAndHasAPromiseIsHandledInternalSlotSetPromiseIsHandledToTrue(promise);5const { ifIsObjectAndHasAPromiseIsHandledInternalSlotSetPromiseIsHandledToTrue } = WPTLib;6ifIsObjectAndHasAPromiseIsHandledInternalSlotSetPromiseIsHandledToTrue(promise);7const { ifIsObjectAndHasAPromiseIsHandledInternalSlotSetPromiseIsHandledToTrue } = WPTLib;8ifIsObjectAndHasAPromiseIsHandledInternalSlotSetPromiseIsHandledToTrue(promise);9const { ifIsObjectAndHasAPromiseIsHandledInternalSlotSetPromiseIsHandledToTrue } = WPTLib;10ifIsObjectAndHasAPromiseIsHandledInternalSlotSetPromiseIsHandledToTrue(promise);11const { ifIsObjectAndHasAPromiseIsHandledInternalSlotSetPromiseIsHandledToTrue } = WPTLib;12ifIsObjectAndHasAPromiseIsHandledInternalSlotSetPromiseIsHandledToTrue(promise);13const { ifIsObjectAndHasAPromiseIsHandledInternalSlotSetPromiseIsHandledToTrue } = WPTLib;

Using AI Code Generation

1ifIsObjectAndHasAPromiseIsHandledInternalSlotSetPromiseIsHandledToTrue = function(promise) {2    if (promise && promise.promiseIsHandledInternalSlot) {3        promise.promiseIsHandledInternalSlot = true;4    }5}6ifIsObjectAndHasAPromiseIsHandledInternalSlotSetPromiseIsHandledToTrue(promise);7ifIsObjectAndHasAPromiseIsHandledInternalSlotSetPromiseIsHandledToTrue = function(promise) {8    if (promise && promise.promiseIsHandledInternalSlot) {9        promise.promiseIsHandledInternalSlot = true;10    }11}12ifIsObjectAndHasAPromiseIsHandledInternalSlotSetPromiseIsHandledToTrue(promise);13ifIsObjectAndHasAPromiseIsHandledInternalSlotSetPromiseIsHandledToTrue = function(promise) {14    if (promise && promise.promiseIsHandledInternalSlot) {15        promise.promiseIsHandledInternalSlot = true;16    }17}18ifIsObjectAndHasAPromiseIsHandledInternalSlotSetPromiseIsHandledToTrue(promise);19ifIsObjectAndHasAPromiseIsHandledInternalSlotSetPromiseIsHandledToTrue = function(promise) {20    if (promise && promise.promiseIsHandledInternalSlot) {21        promise.promiseIsHandledInternalSlot = true;22    }23}24ifIsObjectAndHasAPromiseIsHandledInternalSlotSetPromiseIsHandledToTrue(promise);

Using AI Code Generation

1const { ifIsObjectAndHasAPromiseIsHandledInternalSlotSetPromiseIsHandledToTrue } = require('./resources/test-utils.js');2const { resolve } = require('path');3const { promiseResolvedWith } = require('./resources/testharness.js');4promise_test(t => {5  const promise = promiseResolvedWith(undefined);6  ifIsObjectAndHasAPromiseIsHandledInternalSlotSetPromiseIsHandledToTrue(promise);7  return promise;8}, 'ifIsObjectAndHasAPromiseIsHandledInternalSlotSetPromiseIsHandledToTrue with a promise that fulfills');9promise_test(t => {10  const promise = promiseResolvedWith(undefined);11  ifIsObjectAndHasAPromiseIsHandledInternalSlotSetPromiseIsHandledToTrue(promise);12  return promise;13}, 'ifIsObjectAndHasAPromiseIsHandledInternalSlotSetPromiseIsHandledToTrue with a promise that fulfills');14function ifIsObjectAndHasAPromiseIsHandledInternalSlotSetPromiseIsHandledToTrue(promise) {15  if (typeof promise === 'object' && promise !== null && promise.hasOwnProperty('[[PromiseIsHandled]]')) {16    promise['[[PromiseIsHandled]]'] = true;17  }18}19function promiseResolvedWith(value) {20  return Promise.resolve(value);21}22function promise_test(func, name, properties) {23  const test = async_test(name, properties);24  test.step(() => Promise.resolve().then(() => func(test)).then(test.done, test.done));25}26function async_test(name, properties) {27  return new Test(name, properties, true);28}29function Test(name, properties, isAsync) {30  this.name = name;31  this.properties = properties;32  this.isAsync = isAsync;33  this.phase = 'test_start';34  this.steps = [];

Using AI Code Generation

1var harness = $262.createRealm().global;2var global = this;3var $262 = global.$262;4var asyncTest = harness.asyncTest;5var $DONE = harness.$DONE;6var $ERROR = harness.$ERROR;7var $COMPILE_ERROR = harness.$COMPILE_ERROR;8var $PRINT = harness.$PRINT;9var $DETACHBUFFER = harness.$DETACHBUFFER;10var $DETACHARRAYBUFFER = harness.$DETACHARRAYBUFFER;11var $DETACHARRAYBUFFERS = harness.$DETACHARRAYBUFFERS;12var $CREATEITERATOR = harness.$CREATEITERATOR;13var $CREATEITERABLE = harness.$CREATEITERABLE;14var $CREATEASYNCITERATOR = harness.$CREATEASYNCITERATOR;15var $CREATEASYNCITERABLE = harness.$CREATEASYNCITERABLE;16var $RESOLVEVALUE = harness.$RESOLVEVALUE;17var $RESOLVEVALUEUNWRAPPINGREJECTED = harness.$RESOLVEVALUEUNWRAPPINGREJECTED;18var $RESOLVENEXT = harness.$RESOLVENEXT;19var $RESOLVENEXTUNWRAPPINGREJECTED = harness.$RESOLVENEXTUNWRAPPINGREJECTED;20var $RESOLVE = harness.$RESOLVE;21var $REJECT = harness.$REJECT;22var $REJECTUNWRAPPINGREJECTED = harness.$REJECTUNWRAPPINGREJECTED;23var $CALL = harness.$CALL;24var $CALLBINDING = harness.$CALLBINDING;25var $CALLBINDINGTHIS = harness.$CALLBINDINGTHIS;26var $CALLBINDINGTHISVALUE = harness.$CALLBINDINGTHISVALUE;27var $CONSTRUCT = harness.$CONSTRUCT;28var $CONSTRUCTBINDING = harness.$CONSTRUCTBINDING;29var $CONSTRUCTBINDINGTHIS = harness.$CONSTRUCTBINDINGTHIS;30var $CONSTRUCTBINDINGTHISVALUE = harness.$CONSTRUCTBINDINGTHISVALUE;31var $GET = harness.$GET;32var $GETBINDING = harness.$GETBINDING;33var $GETBINDINGTHIS = harness.$GETBINDINGTHIS;34var $GETBINDINGTHISVALUE = harness.$GETBINDINGTHISVALUE;35var $GETVALUE = harness.$GETVALUE;36var $GETVALUEUNWRAPPINGREJECTED = harness.$GETVALUEUNWRAPPINGREJECTED;37var $GETVALUEUNWRAPPINGREJECTEDWITHABORT = harness.$GETVALUEUNWRAPPINGREJECTEDWITHABORT;

Using AI Code Generation

1test(() => {2  const p = Promise.resolve();3  const p1 = p.then(() => {});4  assert_true(p1.isHandled);5}, 'Promise is handled after a call to then() on it');6test(() => {7  const p = Promise.resolve();8  p.then(() => {});9  assert_false(p.isHandled);10}, 'Promise is not handled after a call to then() on it');11test(() => {12  const p = Promise.resolve();13  p.then(() => {});14  assert_false(p.isHandled);15}, 'Promise is not handled after a call to then() on it');16test(() => {17  const p = Promise.resolve();18  p.then(() => {});19  assert_false(p.isHandled);20}, 'Promise is not handled after a call to then() on it');21test(() => {22  const p = Promise.resolve();23  p.then(() => {});24  assert_false(p.isHandled);25}, 'Promise is not handled after a call to then() on it');26test(() => {27  const p = Promise.resolve();28  p.then(() => {});29  assert_false(p.isHandled);30}, 'Promise is not handled after a call to then() on it');31test(() => {32  const p = Promise.resolve();33  p.then(() => {});34  assert_false(p.isHandled);35}, 'Promise is not handled after a call to then() on it');36test(() => {37  const p = Promise.resolve();38  p.then(() => {});39  assert_false(p.isHandled);40}, 'Promise is not handled after

Automation Testing Tutorials

Learn to execute automation testing from scratch with LambdaTest Learning Hub. Right from setting up the prerequisites to run your first automation test, to following best practices and diving deeper into advanced test scenarios. LambdaTest Learning Hubs compile a list of step-by-step guides to help you be proficient with different test automation frameworks i.e. Selenium, Cypress, TestNG etc.