Remove locale switching support

[ST-DDT]

Clear and concise description of the problem

The locale switching support adds a lot of overhead to the faker instance.
Especially the default instance is huge.

Suggested solution

• Remove locale switching support from Faker.
• The locales have to be set at creation time new Faker([ en ])
• It is possible to provide a single instance as well as a list of locales, that will be merged immediately
• The locale merging behavior isn't changed to the version as it is now, but is exported for users to use themselves (e.g. in build scripts)
• The locale data can be accessed from both cjs and esm using simple imports (Maybe covered by feat: export locales #642)
• The main faker instance is only en
• The documentation contains a hint regarding the use of other locales (Maybe handled as part of Document how to use locales #1322)
• The provided faker instances use a proper locale hierarchy fr_CH -> fr -> en
• Global data such as smiley/iban/mime-types will be moved to their own locale (TBD: global or individual)

Alternative

No response

Additional context

No response

[xDivisionByZerox]

Global data such as smiley/iban/mime-types will be moved to their own locale (TBD: global or individual)

Why cant they be scoped to the module?

[ST-DDT]

They could be. If we drop support for replacing them.
However, that would be another breaking change that should be it's own ticket for better visibility.
Do we have that already somewhere? I remember discussing this before.

[Shinigami92]

I'm somewhat interested to be champion of this, but have some other issues I already provide higher prio from my work-amount
So if someone else claims this before I can start, I'm also fine with that

[matthewmayer]

Just to clarify, if you're currently using a single locale like this:

import { faker } from '@faker-js/faker';
// or with CJS, 
// const {faker} = require("@faker-js/faker")
faker.locale = "de" //or setLocale
console.log(faker.word.noun()) //Glücksspiel

The recommended migration will be to switch to

import { faker } from '@faker-js/faker/locale/de';
// or with CJS, 
// const {faker} = require("@faker-js/faker/locale/de")
console.log(faker.word.noun()) //Glücksspiel

?

[Shinigami92]

We are not sure yet if we still want to support import { faker } from '@faker-js/faker/locale/de' in the long run, but yes.

Our actual plan is to encourage using one of these options (might be slightly different in real world after we done it):

import { faker, fakerDE, localeDE, ... } from '@faker-js/faker'

fakerDE.word.noun()

const myFaker = new Faker({ locale: [localeDE, ...] })
myFaker.word.noun()

[ST-DDT]

Yes or

import { fakerDE } from '@faker-js/faker';

If we use #1735.

[Shinigami92]

Looks like we exactly woke up the same time 🤣

[matthewmayer]

Would it make sense to land this in v9, and in v8 switching locales to a non-en locale still works but add a smaller PR which shows a deprecation message encouraging you to switch to the locale-specific import syntax now?

[Shinigami92]

Would it make sense to land this in v9, and in v8 switching locales to a non-en locale still works but add a smaller PR which shows a deprecation message encouraging you to switch to the locale-specific import syntax now?

We currently didn't find a way how we could achieve that
Do you have any idea?

[ST-DDT]

We could support this:

faker.locale = localeDE;

but not the currently supported:

faker.locale = 'de';

[Shinigami92]

We could support this:

faker.locale = localeDE;

but not the currently supported:

faker.locale = 'de';

Yes, but this wont help as it would be a total breaking change anyways and also does not lead into the direction we are aiming for anyways.
So to me that does not make much sense.

[matthewmayer]

Would it make sense to land this in v9, and in v8 switching locales to a non-en locale still works but add a smaller PR which shows a deprecation message encouraging you to switch to the locale-specific import syntax now?

We currently didn't find a way how we could achieve that Do you have any idea?

rough idea something like #1812

[matthewmayer]

Yes or

import { fakerDE } from '@faker-js/faker';

If we use #1735.

One thing i don't really like about the

import { fakerDE } from '@faker-js/faker'; syntax is that if i change my mind about which locale to support, i now have to change my code in lots of places.

e.g. if i was previously using

import { faker } from '@faker-js/faker';

and then i have lots of calls in my code like

faker.person.name()
faker.location.address()
faker.internet.email()

and then i read the docs and realize i can get more realistic data for my use-case by using the en-GB locale, previously i had to add one line, but now I have to do

import { fakerEN_GB } from '@faker-js/faker';

and then i have to change lots of other lines of code like

fakerEN_GB.person.name()
fakerEN_GB.location.address()
fakerEN_GB.internet.email()

and anywhere where the docs refer to faker.foo.bar i have to remember to do fakerEN_GB.foo.bar
should the docs perhaps encourage instead

import { fakerDE as faker } from '@faker-js/faker';

?

[Shinigami92]

should the docs perhaps encourage instead

import { fakerDE as faker } from '@faker-js/faker';
?

IMO yes, they should 👍
Or at least with a hint, to do this if preferred

[matthewmayer]

i think the main README and https://fakerjs.dev/guide/usage.html should probably show the most common use-cases for importing only ie

1. Default/English only (ESM and CJS)
   e.g. import { faker } from '@faker-js/faker';

2. Other language with default fallback (ESM and CJS)
   e.g. import { fakerDE as faker } from '@faker-js/faker';

And then more unusual cases could be linked to
https://fakerjs.dev/guide/localization.html e.g.

• how to avoid loading the full bundle
• how to customize the fallback locales
• how to import multiple locales

[ST-DDT]

import { fakerDE as faker } from '@faker-js/faker';

Done

And then more unusual cases could be linked to
fakerjs.dev/guide/localization.html

Done, not sure if you had that in mind: 858020c (#1735)