From f300f197da710c1b18a0693c6119cb3ffc7f29ca Mon Sep 17 00:00:00 2001
From: Daeyeon Jeong <daeyeon.dev@gmail.com>
Date: Sun, 2 Oct 2022 19:14:57 +0900
Subject: [PATCH] stream: handle enqueuing chunks when a pending BYOB pull
 request exists

Signed-off-by: Daeyeon Jeong <daeyeon.dev@gmail.com>
PR-URL: https://github.com/nodejs/node/pull/44770
Refs: https://streams.spec.whatwg.org/#readable-byte-stream-controller-enqueue
Reviewed-By: Benjamin Gruenbaum <benjamingr@gmail.com>
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
---
 lib/internal/webstreams/readablestream.js | 72 ++++++++++++++++++-----
 test/wpt/status/streams.json              | 11 ----
 2 files changed, 58 insertions(+), 25 deletions(-)

diff --git a/lib/internal/webstreams/readablestream.js b/lib/internal/webstreams/readablestream.js
index 51e6ca149b1a88..ade543c957dd5a 100644
--- a/lib/internal/webstreams/readablestream.js
+++ b/lib/internal/webstreams/readablestream.js
@@ -2647,13 +2647,22 @@ function readableByteStreamControllerEnqueue(controller, chunk) {
       );
     }
 
-    firstPendingPullInto.buffer =
-      transferArrayBuffer(firstPendingPullInto.buffer);
-  }
+    readableByteStreamControllerInvalidateBYOBRequest(controller);
 
-  readableByteStreamControllerInvalidateBYOBRequest(controller);
+    firstPendingPullInto.buffer = transferArrayBuffer(
+      firstPendingPullInto.buffer
+    );
+
+    if (firstPendingPullInto.type === 'none') {
+      readableByteStreamControllerEnqueueDetachedPullIntoToQueue(
+        controller,
+        firstPendingPullInto
+      );
+    }
+  }
 
   if (readableStreamHasDefaultReader(stream)) {
+    readableByteStreamControllerProcessReadRequestsUsingQueue(controller);
     if (!readableStreamGetNumReadRequests(stream)) {
       readableByteStreamControllerEnqueueChunkToQueue(
         controller,
@@ -2662,6 +2671,10 @@ function readableByteStreamControllerEnqueue(controller, chunk) {
         byteLength);
     } else {
       assert(!queue.length);
+      if (pendingPullIntos.length) {
+        assert(pendingPullIntos[0].type === 'default');
+        readableByteStreamControllerShiftPendingPullInto(controller);
+      }
       const transferredView =
         new Uint8Array(transferredBuffer, byteOffset, byteLength);
       readableStreamFulfillReadRequest(stream, transferredView, false);
@@ -2984,25 +2997,56 @@ function readableByteStreamControllerCancelSteps(controller, reason) {
   return result;
 }
 
+function readableByteStreamControllerFillReadRequestFromQueue(controller, readRequest) {
+  const {
+    queue,
+    queueTotalSize,
+  } = controller[kState];
+  assert(queueTotalSize > 0);
+  const {
+    buffer,
+    byteOffset,
+    byteLength,
+  } = ArrayPrototypeShift(queue);
+
+  controller[kState].queueTotalSize -= byteLength;
+  readableByteStreamControllerHandleQueueDrain(controller);
+  const view = new Uint8Array(buffer, byteOffset, byteLength);
+  readRequest[kChunk](view);
+}
+
+function readableByteStreamControllerProcessReadRequestsUsingQueue(controller) {
+  const {
+    stream,
+    queueTotalSize,
+  } = controller[kState];
+  const { reader } = stream[kState];
+  assert(isReadableStreamDefaultReader(reader));
+
+  while (reader[kState].readRequests.length > 0) {
+    if (queueTotalSize === 0) {
+      return;
+    }
+    readableByteStreamControllerFillReadRequestFromQueue(
+      controller,
+      ArrayPrototypeShift(reader[kState].readRequests),
+    );
+  }
+}
+
 function readableByteStreamControllerPullSteps(controller, readRequest) {
   const {
     pendingPullIntos,
-    queue,
     queueTotalSize,
     stream,
   } = controller[kState];
   assert(readableStreamHasDefaultReader(stream));
   if (queueTotalSize) {
     assert(!readableStreamGetNumReadRequests(stream));
-    const {
-      buffer,
-      byteOffset,
-      byteLength,
-    } = ArrayPrototypeShift(queue);
-    controller[kState].queueTotalSize -= byteLength;
-    readableByteStreamControllerHandleQueueDrain(controller);
-    const view = new Uint8Array(buffer, byteOffset, byteLength);
-    readRequest[kChunk](view);
+    readableByteStreamControllerFillReadRequestFromQueue(
+      controller,
+      readRequest
+    );
     return;
   }
   const {
diff --git a/test/wpt/status/streams.json b/test/wpt/status/streams.json
index 2e8e931e697247..166bcf869080d2 100644
--- a/test/wpt/status/streams.json
+++ b/test/wpt/status/streams.json
@@ -12,17 +12,6 @@
       ]
     }
   },
-  "readable-byte-streams/general.any.js": {
-    "fail": {
-      "expected": [
-        "ReadableStream with byte source: enqueue() discards auto-allocated BYOB request",
-        "ReadableStream with byte source: releaseLock() with pending read(view), read(view) on second reader, enqueue()",
-        "ReadableStream with byte source: autoAllocateChunkSize, releaseLock() with pending read(), read() on second reader, enqueue()",
-        "ReadableStream with byte source: autoAllocateChunkSize, releaseLock() with pending read(), read(view) on second reader, enqueue()",
-        "ReadableStream with byte source: read(view) with 1 element Uint16Array, respond(1), releaseLock(), read() on second reader, enqueue()"
-      ]
-    }
-  },
   "readable-streams/cross-realm-crash.window.js": {
     "skip": "Browser-specific test"
   },