ELDHISTOGRAM open handle

[electriquo]

🐛 Bug Report

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 = "foo";
    > 5 | client.collectDefaultMetrics({ prefix });

To Reproduce

// prom.test.js

const client = require("prom-client");
const prefix = "foo";
client.collectDefaultMetrics({ prefix });

$ npm install prom-client --save
$ npm test prom.test.js

Expected behavior

when running jest --detectOpenHandles, it should not detect ELDHISTOGRAM as open handle

envinfo

$ npx envinfo --preset jest
npx: installed 1 in 2.624s

  System:
    OS: macOS 10.15.4
    CPU: (8) x64 Intel(R) Core(TM) i7-8569U CPU @ 2.80GHz
  Binaries:
    Node: 14.2.0 - ~/.nvm/versions/node/v14.2.0/bin/node
    npm: 6.14.5 - ~/.nvm/versions/node/v14.2.0/bin/npm
  npmPackages:
    jest: ^26.0.1 => 26.0.1

[SimenB]

Since these handles don't actually keep the process open, we should just skip them here: https://github.com/facebook/jest/blob/0e0eeed9d794fe0d6d7e84f555d9684f9e944221/packages/jest-core/src/collectHandles.ts#L55-L57

[electriquo]

@SimenB: will the following due?

if (['PROMISE', 'TIMEWRAP', 'ELDHISTOGRAM'].includes(type)) { 
   return; 
 } 

[SimenB]

You can make that change in your own node_modules locally - if it removes the false positives then yes 🙂

For a PR we'll also need a test, but I can help out with that once a PR is open 👍

[electriquo]

@SimenB: made the modification at ./node_modules/@jest/core/build/collectHandles.js:132 it makes jest hang - jest does not terminate gacefully.

[SimenB]

https://github.com/facebook/jest/releases/tag/v26.4.1

[github-actions]

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