Merge pull request #5778 from cloudflare/yagiz/byte-length-queueing-strategy-size

make sure ByteLengthQueuingStrategy::size handles objects

Author: anonrig

src/workerd/api/streams/readable.c++

@@ -512,6 +512,18 @@ jsg::Optional<uint32_t> ByteLengthQueuingStrategy::size(
     } else if ((value)->IsArrayBufferView()) {
       auto view = value.As<v8::ArrayBufferView>();
       return view->ByteLength();
+    } else {
+      // Per the WHATWG Streams spec, ByteLengthQueuingStrategy.size should return
+      // GetV(chunk, "byteLength"), which means getting the byteLength property
+      // from any object, not just ArrayBuffer/ArrayBufferView.
+      KJ_IF_SOME(obj, jsg::JsValue(value).tryCast<jsg::JsObject>()) {
+        auto byteLength = obj.get(js, "byteLength"_kj);
+        KJ_IF_SOME(num, byteLength.tryCast<jsg::JsNumber>()) {
+          KJ_IF_SOME(val, num.value(js)) {
+            return static_cast<uint32_t>(val);
+          }
+        }
+      }
     }
   }
   return kj::none;

src/wpt/streams-test.ts

@@ -727,13 +727,7 @@ export default {
       'write: returning a rejected promise (second write) should cause writer write() and ready to reject',
     ],
   },
-  'writable-streams/byte-length-queuing-strategy.any.js': {
-    comment:
-      'TypeError: The value cannot be converted because it is not an integer.',
-    expectedFailures: [
-      'Closing a writable stream with in-flight writes below the high water mark delays the close call properly',
-    ],
-  },
+  'writable-streams/byte-length-queuing-strategy.any.js': {},
   'writable-streams/close.any.js': {
     comment: 'To be investigated',
     expectedFailures: [