stream/iter: writevSync queues invalid chunks before throwing

[trivikr]

Version

main

Platform

macOS 26.5.0

Subsystem

stream

What steps will reproduce the bug?

import { push } from 'stream/iter';

const { writer, readable } = push({ highWaterMark: 10 });

try {
  writer.writevSync([1]);
} catch (e) {
  console.log(e.name, e.code);
}

console.log(await readable[Symbol.asyncIterator]().next());

How often does it reproduce? Is there a required condition?

Always

What is the expected behavior? Why is that the expected behavior?

writevSync([1]) should throw a Node validation error like TypeError ERR_INVALID_ARG_TYPE, and the invalid chunk should not be written, so the readable should remain empty/pending.

What do you see instead?

TypeError undefined
[Object: null prototype] { done: false, value: [ 1 ] }

it throws TypeError undefined, and the invalid value is queued.

Additional information

No response