stream: import markPromiseAsHandled directly in pipeTo

mcollina · mcollina · commit 5c8488d00f3d · 2026-05-28T10:33:09.000+02:00
Import markPromiseAsHandled directly from internalBinding('util') in
readablestream.js rather than re-exporting it through
internal/webstreams/util, so the C++ boundary stays visible at the
call site.

Also drop the verbose inline comments describing the
markPromiseAsHandled vs setPromiseHandled choice; the rationale lives
in the PR description.
diff --git a/lib/internal/webstreams/readablestream.js b/lib/internal/webstreams/readablestream.js
@@ -47,6 +47,10 @@ const {
   DOMException,
 } = internalBinding('messaging');
 
+const {
+  markPromiseAsHandled,
+} = internalBinding('util');
+
 const {
   isArrayBufferView,
   isDataView,
@@ -111,7 +115,6 @@ const {
   kState,
   kType,
   lazyTransfer,
-  markPromiseAsHandled,
   nonOpCancel,
   nonOpPull,
   nonOpStart,
@@ -1571,15 +1574,6 @@ function readableStreamPipeTo(
 
         // Write the chunk - we're already in a separate microtask from enqueue
         // because we awaited writer[kState].ready.promise above.
-        //
-        // setPromiseHandled's job here is purely to silence the per-chunk
-        // unhandled-rejection event &mdash; the chain Promise + noop closure it
-        // would allocate are unobserved by anything else (errors propagate
-        // through writer.closed, which pipeTo monitors via watchErrored).
-        // markPromiseAsHandled sets V8's MarkAsHandled + MarkAsSilent flags
-        // directly, with no per-chunk allocation. The LAST state.currentWrite
-        // is awaited in waitForCurrentWrite during shutdown &mdash; markAsHandled
-        // does not affect that subsequent .then chain.
         state.currentWrite = writableStreamDefaultWriterWrite(writer, chunk);
         markPromiseAsHandled(state.currentWrite);
 
@@ -1685,9 +1679,6 @@ class PipeToReadableStreamReadRequest {
     // "ReadableStreamPipeTo" step 15's "chunk steps".
     queueMicrotask(() => {
       this.state.currentWrite = writableStreamDefaultWriterWrite(this.writer, chunk);
-      // See comment in pipeTo's fast path on the markPromiseAsHandled vs
-      // setPromiseHandled choice. The per-chunk silencing has no other
-      // observer; errors reach pipeTo via writer.closed monitoring.
       markPromiseAsHandled(this.state.currentWrite);
       this.promise.resolve(false);
     });
diff --git a/lib/internal/webstreams/util.js b/lib/internal/webstreams/util.js
@@ -35,7 +35,6 @@ const {
     kPending,
   },
   getPromiseDetails,
-  markPromiseAsHandled,
 } = internalBinding('util');
 
 const assert = require('internal/assert');
@@ -226,7 +225,6 @@ module.exports = {
   kState,
   kType,
   lazyTransfer,
-  markPromiseAsHandled,
   nonOpCancel,
   nonOpFlush,
   nonOpPull,
