Faker.js: TypeScript setLocale and locale probleme

[nicolastakashi]

Hey folks!
I have a typescript file that use faker, I import module using this code:

import * as Faker from 'faker';

But if I try to set locale, he don't let me do that because he tell me that locale is read only property.

I tried to use setLocale function, but I can't find it in module

[FloNeu]

Same... also the typings don't have a faker.setLocale()-Methode as described in the README.md.
EDIT: For importing only a sinlge locale, i found you can just import from import * as faker from 'faker/locale/de_AT' for example... still - seems switching locals on the fly is currently not possible...

[Marak]

I'm not really using Typescript, so if anyone can help update the Typescript definitions in a PR it would help.

[Bomberus]

Actually quite simple:
Go to @types/faker, edit index.d.ts

declare namespace Faker {
    interface FakerStatic {
        setLocale(locale: string): void;

Unfortunatly the method setLocale is currently not in npm, see: https://npm.runkit.com/faker/lib/index.js?t=1533829846415

So you manually have to edit the lib/index.js in your node_modules/faker to include

Faker.prototype.setLocale = function (locale) {
  this.locale = locale;
}

Commit https://github.com/Marak/faker.js/commit/8ea2302b05314b84f7cfd4e90e04ea8a17dc5ecb is not yet applied to npm repository.

[nicolastakashi]

@Bomberus I did do the same test that you and I got the same result.
I imagine that we need to send a pull request to types repo and the faker repo.

[Bomberus]

Commit : https://github.com/Marak/faker.js/commit/8ea2302b05314b84f7cfd4e90e04ea8a17dc5ecb

Created an incident hopefully npm maintainer will adopt.

[strobox]

Alt: To use faker with your locale:

var faker = require('../locale/en');
console.log(faker.name.findName());

Doc: here

[Bomberus]

This is a Typescript issue.
Require is not recommended. You could use:

import 'faker/locale/de'

Furthermore, in my usecase I need to dynamically choose a language
like so:
faker.setLocale(faker.random.locale())

I could use

import(`faker/locale/${faker.random.locale()}`).then(() => {
  // continue script
})

But this feels more like a hacky workaround and can be easily avoided, if the npm package is updated!!!

[gjungb]

The easiest way to solve this is like so:
import * as faker from "faker/locale/de";

[acro5piano]

@gjungb Yes, and I may have to import faker before import the locale:

import 'faker'
import * as faker from 'faker/locale/ja'

[somq]

Is there any solution to dynamically set locale in Typescript?

Import

import * as faker from 'faker';
faker.setLocale(faker.random.locale())

Log

Uncaught TypeError: faker__WEBPACK_IMPORTED_MODULE_1__.setLocale is not a function

[acro5piano]

@somq
This is a little bit strange solution, but does await import work for you?

function fakerFactory(locale = 'en') {
  switch (locale) { 
    case 'en':
      return import('faker/locale/en')
    case 'ja':
      return import('faker/locale/ja')
    // ...
  }
}

async function main() {
  const faker = await fakerFactory('en')
  faker.random.locale()

  // ...or
  const faker = await fakerFactory('ja')
  faker.random.locale()
}

[somq]

Hi @acro5piano
Thanks for your answer, I will implement the import this way.

For note;
In theory it works though it's super tricky imo.
Furthermore the async import forces the whole class to be async.

[acro5piano]

I think all we can do practically is:

1. Send a PR to Definitely Typed and wait for its merge
2. Use @ts-ignore above faker.setLocale

[musakasim]

Well actually apparently @types/faker has the definition for setLocale() but faker doesn't.

I imported the locale in the server file and used this one everywhere.

// in server file
import jaFaker from "faker/locale/ja";

export { jaFaker };

//in some other file
import { jaFaker as faker} from '../../../server';