Merge pull request #117 from MattiasBuelens/update-20220418

Update to spec version of 18 April 2022

CHANGELOG.md

@@ -10,6 +10,10 @@
 > - 🏠 Internal
 > - 💅 Polish
 
+## Unreleased
+
+* 👓 Align with [spec version `e9355ce`](https://github.com/whatwg/streams/tree/e9355ce79925947e8eb496563d599c329769d315/) ([#115](https://github.com/MattiasBuelens/web-streams-polyfill/issues/115), [#117](https://github.com/MattiasBuelens/web-streams-polyfill/pull/117))
+
 ## v4.0.0-beta.2 (2022-04-12)
 
 * 🚀 Support calling `ReadableStream.pipeTo(writable)` and `.pipeThrough({ readable, writable })` when `writable` is a native (i.e. not polyfilled) `WritableStream`. ([#99](https://github.com/MattiasBuelens/web-streams-polyfill/pull/99), [#101](https://github.com/MattiasBuelens/web-streams-polyfill/pull/101))

README.md

@@ -76,7 +76,7 @@ If you need to support older browsers or Node versions that do not have a native
 
 ## Compliance
 
-The polyfill implements [version `4b6b93c` (25 Oct 2021)][spec-snapshot] of the streams specification.
+The polyfill implements [version `e9355ce` (18 Apr 2022)][spec-snapshot] of the streams specification.
 
 The polyfill is tested against the same [web platform tests][wpt] that are used by browsers to test their native implementations.
 It aims to pass all tests, although it allows some exceptions for practical reasons:
@@ -120,13 +120,13 @@ Thanks to these people for their work on [the original polyfill][creatorrr-polyf
 [rs-asynciterator]: https://streams.spec.whatwg.org/#rs-asynciterator
 [ws-controller-signal]: https://streams.spec.whatwg.org/#ws-default-controller-signal
 [abortcontroller-polyfill]: https://www.npmjs.com/package/abortcontroller-polyfill
-[spec-snapshot]: https://streams.spec.whatwg.org/commit-snapshots/4b6b93c69e531e2fe45a6ed4cb1484a7ba4eb8bb/
-[wpt]: https://github.com/web-platform-tests/wpt/tree/96ca25f0f7526282c0d47e6bf6a7edd439da1968/streams
-[wpt-bad-buffers]: https://github.com/web-platform-tests/wpt/blob/96ca25f0f7526282c0d47e6bf6a7edd439da1968/streams/readable-byte-streams/bad-buffers-and-views.any.js
+[spec-snapshot]: https://streams.spec.whatwg.org/commit-snapshots/e9355ce79925947e8eb496563d599c329769d315/
+[wpt]: https://github.com/web-platform-tests/wpt/tree/6a46d9cb8d20c510a620141c721b81b460a4ee55/streams
+[wpt-bad-buffers]: https://github.com/web-platform-tests/wpt/blob/6a46d9cb8d20c510a620141c721b81b460a4ee55/streams/readable-byte-streams/bad-buffers-and-views.any.js
 [proposal-arraybuffer-transfer]: https://github.com/domenic/proposal-arraybuffer-transfer
-[ref-impl-transferarraybuffer]: https://github.com/whatwg/streams/blob/4b6b93c69e531e2fe45a6ed4cb1484a7ba4eb8bb/reference-implementation/lib/abstract-ops/ecmascript.js#L16
+[ref-impl-transferarraybuffer]: https://github.com/whatwg/streams/blob/e9355ce79925947e8eb496563d599c329769d315/reference-implementation/lib/abstract-ops/ecmascript.js#L16
 [issue-3]: https://github.com/MattiasBuelens/web-streams-polyfill/issues/3
-[wpt-async-iterator-prototype]: https://github.com/web-platform-tests/wpt/blob/96ca25f0f7526282c0d47e6bf6a7edd439da1968/streams/readable-streams/async-iterator.any.js#L24
+[wpt-async-iterator-prototype]: https://github.com/web-platform-tests/wpt/blob/6a46d9cb8d20c510a620141c721b81b460a4ee55/streams/readable-streams/async-iterator.any.js#L24
 [stub-async-iterator-prototype]: https://github.com/MattiasBuelens/web-streams-polyfill/blob/v4.0.0-beta.2/src/lib/readable-stream/async-iterator.ts#L126-L134
 [wpt-rs-patched-global]: https://github.com/web-platform-tests/wpt/blob/887350c2f46def5b01c4dd1f8d2eee35dfb9c5bb/streams/readable-streams/patched-global.any.js
 [wpt-then-interception]: https://github.com/web-platform-tests/wpt/blob/cf33f00596af295ee0f207c88e23b5f8b0791307/streams/piping/then-interception.any.js

src/lib/abstract-ops/internal-methods.ts

@@ -2,3 +2,4 @@ export const AbortSteps = Symbol('[[AbortSteps]]');
 export const ErrorSteps = Symbol('[[ErrorSteps]]');
 export const CancelSteps = Symbol('[[CancelSteps]]');
 export const PullSteps = Symbol('[[PullSteps]]');
+export const ReleaseSteps = Symbol('[[ReleaseSteps]]');

src/lib/readable-stream.ts

@@ -12,12 +12,14 @@ import {
   AcquireReadableStreamDefaultReader,
   IsReadableStreamDefaultReader,
   ReadableStreamDefaultReader,
+  ReadableStreamDefaultReaderErrorReadRequests,
   type ReadableStreamDefaultReadResult
 } from './readable-stream/default-reader';
 import {
   AcquireReadableStreamBYOBReader,
   IsReadableStreamBYOBReader,
   ReadableStreamBYOBReader,
+  ReadableStreamBYOBReaderErrorReadIntoRequests,
   type ReadableStreamBYOBReadResult
 } from './readable-stream/byob-reader';
 import { ReadableStreamPipeTo } from './readable-stream/pipe';
@@ -459,10 +461,11 @@ export function ReadableStreamCancel<R>(stream: ReadableStream<R>, reason: any):
 
   const reader = stream._reader;
   if (reader !== undefined && IsReadableStreamBYOBReader(reader)) {
-    reader._readIntoRequests.forEach(readIntoRequest => {
+    const readIntoRequests = reader._readIntoRequests;
+    reader._readIntoRequests = new SimpleQueue();
+    readIntoRequests.forEach(readIntoRequest => {
       readIntoRequest._closeSteps(undefined);
     });
-    reader._readIntoRequests = new SimpleQueue();
   }
 
   const sourceCancelPromise = stream._readableStreamController[CancelSteps](reason);
@@ -483,10 +486,11 @@ export function ReadableStreamClose<R>(stream: ReadableStream<R>): void {
   defaultReaderClosedPromiseResolve(reader);
 
   if (IsReadableStreamDefaultReader<R>(reader)) {
-    reader._readRequests.forEach(readRequest => {
+    const readRequests = reader._readRequests;
+    reader._readRequests = new SimpleQueue();
+    readRequests.forEach(readRequest => {
       readRequest._closeSteps();
     });
-    reader._readRequests = new SimpleQueue();
   }
 }
 
@@ -506,19 +510,10 @@ export function ReadableStreamError<R>(stream: ReadableStream<R>, e: any): void
   defaultReaderClosedPromiseReject(reader, e);
 
   if (IsReadableStreamDefaultReader<R>(reader)) {
-    reader._readRequests.forEach(readRequest => {
-      readRequest._errorSteps(e);
-    });
-
-    reader._readRequests = new SimpleQueue();
+    ReadableStreamDefaultReaderErrorReadRequests(reader, e);
   } else {
     assert(IsReadableStreamBYOBReader(reader));
-
-    reader._readIntoRequests.forEach(readIntoRequest => {
-      readIntoRequest._errorSteps(e);
-    });
-
-    reader._readIntoRequests = new SimpleQueue();
+    ReadableStreamBYOBReaderErrorReadIntoRequests(reader, e);
   }
 }
 

src/lib/readable-stream/byob-reader.ts

@@ -210,11 +210,7 @@ export class ReadableStreamBYOBReader {
       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);
+    ReadableStreamBYOBReaderRelease(this);
   }
 }
 
@@ -270,6 +266,20 @@ export function ReadableStreamBYOBReaderRead<T extends ArrayBufferView>(
   }
 }
 
+export function ReadableStreamBYOBReaderRelease(reader: ReadableStreamBYOBReader) {
+  ReadableStreamReaderGenericRelease(reader);
+  const e = new TypeError('Reader was released');
+  ReadableStreamBYOBReaderErrorReadIntoRequests(reader, e);
+}
+
+export function ReadableStreamBYOBReaderErrorReadIntoRequests(reader: ReadableStreamBYOBReader, e: any) {
+  const readIntoRequests = reader._readIntoRequests;
+  reader._readIntoRequests = new SimpleQueue();
+  readIntoRequests.forEach(readIntoRequest => {
+    readIntoRequest._errorSteps(e);
+  });
+}
+
 // Helper functions for the ReadableStreamBYOBReader.
 
 function byobReaderBrandCheckException(name: string): TypeError {

src/lib/readable-stream/byte-stream-controller.ts

@@ -3,6 +3,7 @@ import { SimpleQueue } from '../simple-queue';
 import { ResetQueue } from '../abstract-ops/queue-with-sizes';
 import type { ReadRequest } from './default-reader';
 import {
+  IsReadableStreamDefaultReader,
   ReadableStreamAddReadRequest,
   ReadableStreamFulfillReadRequest,
   ReadableStreamGetNumReadRequests,
@@ -27,7 +28,7 @@ import {
   IsDetachedBuffer,
   TransferArrayBuffer
 } from '../abstract-ops/ecmascript';
-import { CancelSteps, PullSteps } from '../abstract-ops/internal-methods';
+import { CancelSteps, PullSteps, ReleaseSteps } from '../abstract-ops/internal-methods';
 import { promiseResolvedWith, uponPromise } from '../helpers/webidl';
 import { assertRequiredArgument, convertUnsignedLongLongWithEnforceRange } from '../validators/basic';
 
@@ -155,7 +156,7 @@ interface DefaultPullIntoDescriptor {
   bytesFilled: number;
   elementSize: number;
   viewConstructor: ArrayBufferViewConstructor<Uint8Array>;
-  readerType: 'default';
+  readerType: 'default' | 'none';
 }
 
 interface BYOBPullIntoDescriptor<T extends ArrayBufferView = ArrayBufferView> {
@@ -166,7 +167,7 @@ interface BYOBPullIntoDescriptor<T extends ArrayBufferView = ArrayBufferView> {
   bytesFilled: number;
   elementSize: number;
   viewConstructor: ArrayBufferViewConstructor<T>;
-  readerType: 'byob';
+  readerType: 'byob' | 'none';
 }
 
 /**
@@ -313,14 +314,7 @@ export class ReadableByteStreamController {
     if (this._queueTotalSize > 0) {
       assert(ReadableStreamGetNumReadRequests(stream) === 0);
 
-      const entry = this._queue.shift()!;
-      this._queueTotalSize -= entry.byteLength;
-
-      ReadableByteStreamControllerHandleQueueDrain(this);
-
-      const view = new Uint8Array(entry.buffer, entry.byteOffset, entry.byteLength);
-
-      readRequest._chunkSteps(view);
+      ReadableByteStreamControllerFillReadRequestFromQueue(this, readRequest);
       return;
     }
 
@@ -351,6 +345,17 @@ export class ReadableByteStreamController {
     ReadableStreamAddReadRequest(stream, readRequest);
     ReadableByteStreamControllerCallPullIfNeeded(this);
   }
+
+  /** @internal */
+  [ReleaseSteps](): void {
+    if (this._pendingPullIntos.length > 0) {
+      const firstPullInto = this._pendingPullIntos.peek();
+      firstPullInto.readerType = 'none';
+
+      this._pendingPullIntos = new SimpleQueue();
+      this._pendingPullIntos.push(firstPullInto);
+    }
+  }
 }
 
 Object.defineProperties(ReadableByteStreamController.prototype, {
@@ -442,6 +447,7 @@ function ReadableByteStreamControllerCommitPullIntoDescriptor<T extends ArrayBuf
   pullIntoDescriptor: PullIntoDescriptor<T>
 ) {
   assert(stream._state !== 'errored');
+  assert(pullIntoDescriptor.readerType !== 'none');
 
   let done = false;
   if (stream._state === 'closed') {
@@ -479,6 +485,34 @@ function ReadableByteStreamControllerEnqueueChunkToQueue(controller: ReadableByt
   controller._queueTotalSize += byteLength;
 }
 
+function ReadableByteStreamControllerEnqueueClonedChunkToQueue(controller: ReadableByteStreamController,
+                                                               buffer: ArrayBufferLike,
+                                                               byteOffset: number,
+                                                               byteLength: number) {
+  let clonedChunk;
+  try {
+    clonedChunk = buffer.slice(byteOffset, byteOffset + byteLength);
+  } catch (cloneE) {
+    ReadableByteStreamControllerError(controller, cloneE);
+    throw cloneE;
+  }
+  ReadableByteStreamControllerEnqueueChunkToQueue(controller, clonedChunk, 0, byteLength);
+}
+
+function ReadableByteStreamControllerEnqueueDetachedPullIntoToQueue(controller: ReadableByteStreamController,
+                                                                    firstDescriptor: PullIntoDescriptor) {
+  assert(firstDescriptor.readerType === 'none');
+  if (firstDescriptor.bytesFilled > 0) {
+    ReadableByteStreamControllerEnqueueClonedChunkToQueue(
+      controller,
+      firstDescriptor.buffer,
+      firstDescriptor.byteOffset,
+      firstDescriptor.bytesFilled
+    );
+  }
+  ReadableByteStreamControllerShiftPendingPullInto(controller);
+}
+
 function ReadableByteStreamControllerFillPullIntoDescriptorFromQueue(controller: ReadableByteStreamController,
                                                                      pullIntoDescriptor: PullIntoDescriptor) {
   const elementSize = pullIntoDescriptor.elementSize;
@@ -567,6 +601,7 @@ function ReadableByteStreamControllerProcessPullIntoDescriptorsUsingQueue(contro
     }
 
     const pullIntoDescriptor = controller._pendingPullIntos.peek();
+    assert(pullIntoDescriptor.readerType !== 'none');
 
     if (ReadableByteStreamControllerFillPullIntoDescriptorFromQueue(controller, pullIntoDescriptor)) {
       ReadableByteStreamControllerShiftPendingPullInto(controller);
@@ -579,6 +614,18 @@ function ReadableByteStreamControllerProcessPullIntoDescriptorsUsingQueue(contro
   }
 }
 
+function ReadableByteStreamControllerProcessReadRequestsUsingQueue(controller: ReadableByteStreamController) {
+  const reader = controller._controlledReadableByteStream._reader;
+  assert(IsReadableStreamDefaultReader(reader));
+  while (reader._readRequests.length > 0) {
+    if (controller._queueTotalSize === 0) {
+      return;
+    }
+    const readRequest = reader._readRequests.shift();
+    ReadableByteStreamControllerFillReadRequestFromQueue(controller, readRequest);
+  }
+}
+
 export function ReadableByteStreamControllerPullInto<T extends ArrayBufferView>(
   controller: ReadableByteStreamController,
   view: T,
@@ -657,6 +704,10 @@ function ReadableByteStreamControllerRespondInClosedState(controller: ReadableBy
                                                           firstDescriptor: PullIntoDescriptor) {
   assert(firstDescriptor.bytesFilled === 0);
 
+  if (firstDescriptor.readerType === 'none') {
+    ReadableByteStreamControllerShiftPendingPullInto(controller);
+  }
+
   const stream = controller._controlledReadableByteStream;
   if (ReadableStreamHasBYOBReader(stream)) {
     while (ReadableStreamGetNumReadIntoRequests(stream) > 0) {
@@ -673,6 +724,12 @@ function ReadableByteStreamControllerRespondInReadableState(controller: Readable
 
   ReadableByteStreamControllerFillHeadPullIntoDescriptor(controller, bytesWritten, pullIntoDescriptor);
 
+  if (pullIntoDescriptor.readerType === 'none') {
+    ReadableByteStreamControllerEnqueueDetachedPullIntoToQueue(controller, pullIntoDescriptor);
+    ReadableByteStreamControllerProcessPullIntoDescriptorsUsingQueue(controller);
+    return;
+  }
+
   if (pullIntoDescriptor.bytesFilled < pullIntoDescriptor.elementSize) {
     return;
   }
@@ -682,8 +739,12 @@ function ReadableByteStreamControllerRespondInReadableState(controller: Readable
   const remainderSize = pullIntoDescriptor.bytesFilled % pullIntoDescriptor.elementSize;
   if (remainderSize > 0) {
     const end = pullIntoDescriptor.byteOffset + pullIntoDescriptor.bytesFilled;
-    const remainder = ArrayBufferSlice(pullIntoDescriptor.buffer, end - remainderSize, end);
-    ReadableByteStreamControllerEnqueueChunkToQueue(controller, remainder, 0, remainder.byteLength);
+    ReadableByteStreamControllerEnqueueClonedChunkToQueue(
+      controller,
+      pullIntoDescriptor.buffer,
+      end - remainderSize,
+      remainderSize
+    );
   }
 
   pullIntoDescriptor.bytesFilled -= remainderSize;
@@ -807,12 +868,15 @@ export function ReadableByteStreamControllerEnqueue(controller: ReadableByteStre
         'The BYOB request\'s buffer has been detached and so cannot be filled with an enqueued chunk'
       );
     }
+    ReadableByteStreamControllerInvalidateBYOBRequest(controller);
     firstPendingPullInto.buffer = TransferArrayBuffer(firstPendingPullInto.buffer);
+    if (firstPendingPullInto.readerType === 'none') {
+      ReadableByteStreamControllerEnqueueDetachedPullIntoToQueue(controller, firstPendingPullInto);
+    }
   }
 
-  ReadableByteStreamControllerInvalidateBYOBRequest(controller);
-
   if (ReadableStreamHasDefaultReader(stream)) {
+    ReadableByteStreamControllerProcessReadRequestsUsingQueue(controller);
     if (ReadableStreamGetNumReadRequests(stream) === 0) {
       assert(controller._pendingPullIntos.length === 0);
       ReadableByteStreamControllerEnqueueChunkToQueue(controller, transferredBuffer, byteOffset, byteLength);
@@ -851,6 +915,21 @@ export function ReadableByteStreamControllerError(controller: ReadableByteStream
   ReadableStreamError(stream, e);
 }
 
+export function ReadableByteStreamControllerFillReadRequestFromQueue(
+  controller: ReadableByteStreamController,
+  readRequest: ReadRequest<Uint8Array>
+) {
+  assert(controller._queueTotalSize > 0);
+
+  const entry = controller._queue.shift();
+  controller._queueTotalSize -= entry.byteLength;
+
+  ReadableByteStreamControllerHandleQueueDrain(controller);
+
+  const view = new Uint8Array(entry.buffer, entry.byteOffset, entry.byteLength);
+  readRequest._chunkSteps(view);
+}
+
 export function ReadableByteStreamControllerGetBYOBRequest(
   controller: ReadableByteStreamController
 ): ReadableStreamBYOBRequest | null {

src/lib/readable-stream/default-controller.ts

@@ -13,7 +13,7 @@ import type { ReadableStream } from '../readable-stream';
 import { IsReadableStreamLocked, ReadableStreamClose, ReadableStreamError } from '../readable-stream';
 import type { ValidatedUnderlyingSource } from './underlying-source';
 import { setFunctionName, typeIsObject } from '../helpers/miscellaneous';
-import { CancelSteps, PullSteps } from '../abstract-ops/internal-methods';
+import { CancelSteps, PullSteps, ReleaseSteps } from '../abstract-ops/internal-methods';
 import { promiseResolvedWith, uponPromise } from '../helpers/webidl';
 
 /**
@@ -132,6 +132,11 @@ export class ReadableStreamDefaultController<R> {
       ReadableStreamDefaultControllerCallPullIfNeeded(this);
     }
   }
+
+  /** @internal */
+  [ReleaseSteps](): void {
+    // Do nothing.
+  }
 }
 
 Object.defineProperties(ReadableStreamDefaultController.prototype, {