node does not exit

[electriquo]

i use prom-client version 12.0.0.

when i run jest --detectOpenHandles i get

Jest has detected the following 1 open handle potentially keeping Jest from exiting:

  ●  ELDHISTOGRAM

      3 | const client = require("prom-client");
      4 | const prefix = "name_";
    > 5 | client.collectDefaultMetrics({ prefix });

following not returning an interval, i saw the docs update. also looked at the tests and saw that indeed clearInterval() is called.

could one please shed the light on how should prom-client be closeed properly?

[zbjornson]

I think we need to be disabling the event loop delay histogram in an exit handler...

[sam-github]

It should be unrefed, best to avoid exit handlers, except it doesn't appear to have a documented unref. It might be there anyway, I'll go look.

subject should be fixed, "exists" was meant to be "exit", I think.

[sam-github]

This is a false-positive on the part of jest, I can't reproduce a scenario where node does not exit, either by calling the default collector, or by call perf_hooks.

@y0y0z can you provide a reproduction of failure to exit?

This may be a bug that should be reported to jest.

[sam-github]

Also, note that while the tests are calling clearInterval(), this is either legacy code to be deleted, or possibly, a check of backward compatibility of the API. The so-called interval in interval = collectDefaultMetrics() is now always undefined (no interval timer is used anymore).

[electriquo]

Also, note that while the tests are calling clearInterval(), this is either legacy code to be deleted, or possibly, a check of backward compatibility of the API. The so-called interval in interval = collectDefaultMetrics() is now always undefined (no interval timer is used anymore).

@sam-github: #342

indeed the tests are for the old implementation and does not coincide with the issue #342.

currently, i do not have a repository to reproduce the issue, will try my best to share something later on. meanwhile, i think revising the current test and fix them to reflect the changes, might reveal the issue.

[sam-github]

Removing those lines from the tests doesn't change jest's opinion about whether prom-client is leaking handles. If there is no problem with prom-client (and I can't find one), then the issue should be closed and opened against jest.

[SimenB]

Jest should not count ELDHISTOGRAM or PerformanceObserver. They don't keep the process open, so Jest shouldn't care about them.

Wanna send a PR? Code is here: https://github.com/facebook/jest/blob/0e0eeed9d794fe0d6d7e84f555d9684f9e944221/packages/jest-core/src/collectHandles.ts#L55-L57

If you don't have time to send a PR, could you open up an issue?

(I'm one of the maintainers of Jest).

[electriquo]

@SimenB: thank you. i opened an issue.

[SimenB]

Thanks!

[micaelmbagira]

@SimenB PR is open jestjs/jest#11123