structuredClone Serializing a non-serializable platform object succeeds

[RedYetiDev]

In Node.js, the following snippet succeeds, whereas, in the browser, it throws a DataCloneError:

structuredClone(new Response());

This is causing the following WPT to fail:

structuredCloneBatteryOfTests.push({
  description: 'Serializing a non-serializable platform object fails',
  async f(runner, t) {
    const request = new Response();
    await promise_rejects_dom(
      t,
      "DataCloneError",
      runner.structuredClone(request)
    );
  }
});

[KhafraDev]

A JavaScript value value is a platform object if Type(value) is Object and if value has a [[PrimaryInterface]] internal slot.

The primary interface of a platform object is the value of the object’s [[PrimaryInterface]] internal slot, which is the most-derived interface that it implements.

Request's webidl declaration does not extend anything, therefore it's a platform object.

Hopefully this may help someone.

[KhafraDev]

@nodejs/web-standards @joyeecheung

[jazelly]

I am a bit curious how undici will adopt this to address this issue. Don't get me wrong, it will address the issue, but the process will probably be like:

1. release that PR
2. land a new commit on undici to mark all classes uncloneable, which might be semver-major
3. node waits for that undici release and bump the deps

The whole thing could be dragged a bit long, and I am thinking should we consider the fast win with a TODO to drop it once the above process is settled?

[KhafraDev]

It won't be a semver-major issue, changes that are made for spec-compatibility are usually considered bug fixes. This bug was only caught in a WPT - the behavior is far too niche to justify the performance overhead of constructing every Response, Request, FormData, Headers, etc.

[RedYetiDev]

@jazelly just confirming the Unidici PR fixed this, and it'll be good-to-go when the next version of Undici releases?

[jazelly]

Yes, once that's released and bumped in node, this should be resolved.

[RedYetiDev]

I'm gonna close this, as while the latest Node.js doesn't have the Undici needed, it's no longer actionable as an issue. Thx!