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Robert Rees
Robert Rees

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Make your Faker unit tests run faster with this one weird tip

FakerJS has a bug that is a classic example of over-eager initialisation.

Naively importing the library as per the Readme can lead to a massive slowdown in tests that are often meant to be some of the fastest in your suite.

In my case I was importing string functionality to tests content boundaries so even though I was actually trying to create any localised data I was initialising all of the localised content leading to my tests timing out for a simple validation.

The weird tip is simply to import the en locale (unless you specifically what a specific localised set of data)

import { faker } from '@faker-js/faker/locale/en';
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The English locale is also loaded for other languages so this genuinely seems the quickest import.

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