the main thread doesn't wait for AbortSignal

[dhcmrlchtdj]

Version

v19.5.0

Platform

Darwin MacBookAir.local 22.3.0 Darwin Kernel Version 22.3.0: Thu Jan 5 20:49:43 PST 2023; root:xnu-8792.81.2~2/RELEASE_ARM64_T8103 arm64

Subsystem

No response

What steps will reproduce the bug?

$ node -e 'setTimeout(() => console.log("setTimeout"), 1000)'
setTimeout

$ node -e 'AbortSignal.timeout(1000).addEventListener("abort", () => console.log("AbortSignal"))'
$ # no output

$ node -e 'setTimeout(() => console.log("setTimeout"), 1100); AbortSignal.timeout(1000).addEventListener("abort", () => console.log("AbortSignal"))'
AbortSignal
setTimeout

the node process will wait for setTimeout, but not for AbortSignal.

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

No response

What is the expected behavior?

node process should wait for AbortSignal and log AbortSignal after 1000ms.

What do you see instead?

the node process returns immediately, the AbortSignal.timeout is ignored.

Additional information

No response

[MoLow]

This is by design.
according to your expectation, this piece of code should hold the process from exiting for 1000ms, even if the request was completed before:

await fetch({ signal: AbortSignal.timeout(1000) })

[dhcmrlchtdj]

if a request is completed before the signal timeout, it could remove the event listener on the signal. this is what undici does.

if there is no callback listening to a signal, the timer could be dropped safety.
when a callback is still attached, the main thread should wait for the timer.

[jasnell]

As indicated, the current behavior is by design. If you want to keep the process alive, either use a regular timer (or one of the Promise-based timers).

[dhcmrlchtdj]

thanks for your suggestion.