this package was slowing down my jest tests

[Alino]

I have been debugging my jest tests all day because they were failing due to timeouts, and sometimes passing but it took like 200 seconds sometimes to run few simple tests. Long story short, I have disabled creating my random mock data with faker and used hard-coded data instead. Now my jest runs in few seconds.

Note that it was not slowing down particular unit tests (they took few milliseconds), but the whole jest runtime took over hundreds of seconds. So it does not play nice with jest runner or whatever on windows 10 and also WSL.

[xDivisionByZerox]

Please provide a minimal test suite where this issue is present.
I'm using faker for personal and business tests in jest for fuzzing and have no problems at all with faker. Jest itself is running terribly slow in windows machines (for me even with WSL), so please test your jest test suite on a linux VM and see if it happens there as well.

[Alino]

Sorry I can't spend more time on this by recreating a repo. But I can share the code change that has fixed my problem. Now my jest runs in 10 seconds instead of 200 seconds.

I was using version 6.2.0, I have also tried upgrading to the latest 7.3.0 but the problem was still there. Only removing it helped.

[Shinigami92]

Try @faker-js/faker/locale/en and test again

[maximgeerinck]

/locale/en

I can verify that this sped up my tests a lot in some cases

[wodCZ]

I've isolated my tests slowdown to Faker too.

console.time('require');
const faker = require('@faker-js/faker');
console.timeEnd('require');

The require takes on average 1.6s on 2019 MacBook Pro

console.time('require');
const faker = require('@faker-js/faker/locale/en');
console.timeEnd('require');

Changing the import to locale/en reduces the require time to ~180ms on average.

[ST-DDT]

Team decision

We should amend the readme usage section to contain a hint why the user should use a locale specific variant.
https://github.com/faker-js/faker#-usage

The docs should also mention it in the usage section ( locale specific versions ).

Also the downsides of the the locale specific versions might need some documentation.

[CookrC]

Hello, I am willing to start updating the documentation relating to this issue! If you do not mind, I would like to be assigned to this issue.
Thanks!

[ST-DDT]

Thanks for your help.

[ST-DDT]

Note that we already have a page partially mentioning this, but the main usage page might need a hint for this as well and the localization page might need some more details.
https://fakerjs.dev/guide/localization.html