Internal Assertion in `AbortSignal`

[avivkeller]

I am working on updating the Web Platform Tests in #54468, but ran into an issue occuring with AbortSignal. I narrowed down the issue to a minimal reproduction, with leads to an ERR_INTERNAL_ASSERTION:

const controller = new AbortController();
const signal1 = AbortSignal.any([controller.signal]);

controller.signal.addEventListener('abort', () => {
    AbortSignal.any([signal1]);
})

controller.abort();

node:internal/event_target:1090
  process.nextTick(() => { throw err; });
                           ^

Error [ERR_INTERNAL_ASSERTION]: This is caused by either a bug in Node.js or incorrect usage of Node.js internals.
Please open an issue with this stack trace at https://github.com/nodejs/node/issues

    at assert (node:internal/assert:14:11)
    at AbortSignal.any (node:internal/abort_controller:253:11)
    at AbortSignal.<anonymous> (/repro.js:5:17)
    at [nodejs.internal.kHybridDispatch] (node:internal/event_target:816:20)
    at AbortSignal.dispatchEvent (node:internal/event_target:751:26)
    at abortSignal (node:internal/abort_controller:374:10)
    at AbortController.abort (node:internal/abort_controller:396:5)
    at Object.<anonymous> (/repro.js:8:12)
    at Module._compile (node:internal/modules/cjs/loader:1546:14)
    at Module._extensions..js (node:internal/modules/cjs/loader:1691:10) {
  code: 'ERR_INTERNAL_ASSERTION'
}

Node.js v22.7.0

The failed assertion is

node/lib/internal/abort_controller.js

Line 253 in 885692a

assert(!sourceSignalRef.aborted);

---

It seems to me that Node.js's current behavior is to fail the assertion when a signal has already aborted, however the WPT's expected behavior is that "Dependent signals for AbortSignal.any() are marked aborted before abort events fire":
https://github.com/web-platform-tests/wpt/blob/e78446e34a1921371658a5df08c71d83f50a2a2f/dom/abort/resources/abort-signal-any-tests.js#L193

[avivkeller]

Spec: https://dom.spec.whatwg.org/#create-a-dependent-abort-signal

[shubhamsugara22]

Dependent abort signal that allow one or more 'AbortSignal' object to depend on each other
the dependent signal will automatically aborted if the parent is aborted . So the links explains the behavior that AbortSignal should behave like that but it fails assertion when signal has already been aborted .
Looks like you can test the case by skipping the signal if aborted or check if the signal is aborted creating an exception handler
this 2 case can be tested to see if the impact and early test if we modification can be made to this
if you have any other way please discuss?
@redyetidev

[avivkeller]

I'm sorry, I'm not exactly following your comment, could you elaborate?

The issue, to clarify, is that in internal assertion is thrown in a place where a signal should be returned (to be WPT compliant).

[shubhamsugara22]

😞 Sorry for that i meant this:
What is understood
A dependent abort signal is designed so that when the parent signal is aborted, the dependent signal should automatically follow suit. The DOM specification outlines this behavior, but it seems that Node.js currently fails this internal assertion when a signal has already been aborted.
Solution we can try ?
One possible way to address this would be to check if the signal has been aborted before attempting to create a dependent signal. If it has, we could skip it or handle it with an exception. This would help ensure compliance with the WPT. We could start by testing these approaches to see if they resolve the issue.

If you have any other suggestions or ideas on how to ensure WPT compliance while avoiding this assertion, I'd love to discuss them!

[avivkeller]

Ahh okay. If you have an idea/improvement, opening a PR is a great way to contribute

[shubhamsugara22]

yeah , thanks will try to open one for this