feat: add setLanguage and setLocale for web worker use cases

Signed-off-by: Ferdinand Thiessen <opensource@fthiessen.de>

Author: susnux

lib/globals.d.ts

@@ -3,7 +3,7 @@
  * SPDX-License-Identifier: GPL-3.0-or-later
  */
 
-/* eslint-disable no-var, camelcase */
+/* eslint-disable camelcase */
 
 import type { PluralFunction, Translations } from './registry.ts'
 

lib/locale.ts

@@ -18,6 +18,22 @@ export function getCanonicalLocale(): string {
 	return getLocale().replaceAll(/_/g, '-')
 }
 
+/**
+ * Set the current user's language (locally).
+ * This is to be used only for e.g. usage within web workers etc.
+ *
+ * @param locale - The new language code
+ * @since 3.4.0
+ */
+export function setLocale(locale: string): void {
+	globalThis._nc_l10n_locale = locale
+
+	// also for browsers set the DOM
+	if (typeof document !== 'undefined') {
+		document.documentElement.dataset.locale = locale
+	}
+}
+
 /**
  * Returns the user's language
  */
@@ -27,8 +43,10 @@ export function getLanguage(): string {
 
 /**
  * Set the current user's language (locally).
+ * This is to be used only for e.g. usage within web workers etc.
  *
  * @param lang - The new language code
+ * @since 3.4.0
  */
 export function setLanguage(lang: string): void {
 	globalThis._nc_l10n_language = lang

tests/gettext.test.ts

@@ -6,8 +6,7 @@
 import { po } from 'gettext-parser'
 import { beforeEach, describe, expect, it, vi } from 'vitest'
 import { getGettextBuilder } from '../lib/gettext.ts'
-
-const setLanguage = (lang: string) => { globalThis._nc_l10n_language = lang }
+import { setLanguage } from '../lib/locale.ts'
 
 describe('gettext', () => {
 	beforeEach(() => {

tests/is-rtl.test.ts

@@ -4,12 +4,12 @@
  */
 
 import { beforeEach, describe, expect, it } from 'vitest'
-import { isRTL } from '../lib/locale'
-
-const setLanguage = (lang: string) => { globalThis._nc_l10n_language = lang }
+import { isRTL, setLanguage } from '../lib/locale.ts'
 
 describe('isRTL', () => {
-	beforeEach(() => { globalThis._nc_l10n_locale = 'en' })
+	beforeEach(() => {
+		globalThis._nc_l10n_locale = 'en'
+	})
 
 	it('falls back to English which is LTR', () => {
 		// Expect fallback which is English = LTR

tests/loadTranslations.test.ts

@@ -8,21 +8,13 @@ import type { SetupServerApi } from 'msw/node'
 import { http, HttpResponse } from 'msw'
 import { setupServer } from 'msw/node'
 import { afterAll, afterEach, beforeAll, beforeEach, describe, expect, it, vi } from 'vitest'
+import { setLanguage } from '../lib/locale.ts'
 import { loadTranslations, register, translate, unregister } from '../lib/translation.ts'
 
 vi.mock('@nextcloud/router', () => ({
 	generateFilePath: (app: string, type: string, path: string) => `http://localhost/${app}/${type}/${path}`,
 }))
 
-/**
- * Mock the langauge
- *
- * @param lang - The language to mock
- */
-function setLanguage(lang: string): void {
-	globalThis._nc_l10n_language = lang
-}
-
 const requestHandlers = [
 	http.get('http://localhost/myapp/l10n/de.json', () => HttpResponse.json({
 		translations: {

tests/locale.test.ts

@@ -9,47 +9,75 @@ beforeEach(() => vi.resetModules())
 
 describe('getLanguage', () => {
 	it('returns the set language as it is', async () => {
-		setLanguage('de-DE')
+		mockLanguage('de-DE')
 		expect(await getLanguage()).toEqual('de-DE')
 	})
 
 	it('returns the navigator language if no language is set', async () => {
 		const spy = vi.spyOn(navigator, 'language', 'get')
 		spy.mockImplementationOnce(() => 'ar-EG')
 
-		setLanguage(undefined)
+		mockLanguage(undefined)
 		expect(await getLanguage()).toEqual('ar-EG')
 		expect(spy).toHaveBeenCalledOnce()
 	})
 })
 
+describe('setLanguage', () => {
+	it('does set the global state', async () => {
+		mockLanguage('de')
+		await setLanguage('ar')
+		expect(globalThis._nc_l10n_language).toBe('ar')
+	})
+
+	it.skipIf(typeof globalThis.document === 'undefined')('does set the DOM attribute', async () => {
+		mockLanguage('de')
+		await setLanguage('ar')
+		expect(document.documentElement.lang).toBe('ar')
+	})
+})
+
 describe('getLocale', () => {
 	it('returns the set locale as it is with underscore', async () => {
-		setLocale('de_DE')
+		mockLocale('de_DE')
 		expect(await getLocale()).toEqual('de_DE')
 	})
 
 	it('returns the environment locale with underscore if no locale is set', async () => {
-		setLocale(undefined)
+		mockLocale(undefined)
 		expect(await getLocale()).toEqual(process.env.LANG?.replaceAll('-', '_').split('.')[0])
 	})
 })
 
+describe('setLocale', () => {
+	it('does set the global state', async () => {
+		mockLocale('de_DE')
+		await setLocale('ar')
+		expect(globalThis._nc_l10n_locale).toBe('ar')
+	})
+
+	it.skipIf(typeof globalThis.document === 'undefined')('does set the DOM attribute', async () => {
+		mockLocale('de_DE')
+		await setLocale('ar')
+		expect(document.documentElement.dataset.locale).toBe('ar')
+	})
+})
+
 describe('getCanonicalLocale', () => {
 	it('returns the set locale with hyphen', async () => {
-		setLocale('de_DE')
+		mockLocale('de_DE')
 		expect(await getCanonicalLocale()).toEqual('de-DE')
 	})
 
 	it('returns the set locale with multiple hyphen', async () => {
-		setLocale('az_Cyrl_AZ')
+		mockLocale('az_Cyrl_AZ')
 		expect(await getCanonicalLocale()).toEqual('az-Cyrl-AZ')
 	})
 
 	it('returns the environment locale with hyphen if no locale is set', async () => {
 		expect(process.env.LANG).toBeTruthy()
 
-		setLocale(undefined)
+		mockLocale(undefined)
 		expect(await getCanonicalLocale()).toEqual(process.env.LANG!.split('.')[0])
 	})
 })
@@ -69,11 +97,24 @@ async function getLanguage() {
 	return getLanguage()
 }
 
-function setLanguage(lang?: string) {
+async function setLocale(locale: string) {
+	const { setLocale } = await import('../lib/locale.ts')
+	return setLocale(locale)
+}
+
+async function setLanguage(language: string) {
+	const { setLanguage } = await import('../lib/locale.ts')
+	return setLanguage(language)
+}
+
+function mockLanguage(lang?: string) {
 	// @ts-expect-error - Mocking global state
 	globalThis._nc_l10n_language = lang
 }
-function setLocale(locale?: string) {
+function mockLocale(locale?: string) {
 	// @ts-expect-error - Mocking global state
 	globalThis._nc_l10n_locale = locale
+	if (typeof globalThis.document !== 'undefined') {
+		delete globalThis.document.documentElement.dataset.locale
+	}
 }

tests/time.test.ts

@@ -4,10 +4,9 @@
  */
 
 import { beforeAll, beforeEach, describe, expect, it, test, vi } from 'vitest'
+import { setLanguage } from '../lib/locale.ts'
 import { formatRelativeTime } from '../lib/time.ts'
 
-const setLanguage = (lang: string) => { globalThis._nc_l10n_language = lang }
-
 describe('time - formatRelativeTime', () => {
 	beforeAll(() => {
 		vi.useFakeTimers({ now: new Date('2025-01-01T00:00:00Z') })

tests/translation.test.ts

@@ -3,9 +3,8 @@
  * SPDX-License-Identifier: GPL-3.0-or-later
  */
 
-import type { NextcloudWindowWithRegistry } from '../lib/registry.ts'
-
 import { beforeAll, beforeEach, describe, expect, it } from 'vitest'
+import { setLanguage, setLocale } from '../lib/locale.ts'
 import {
 	getPlural,
 	n,
@@ -16,9 +15,6 @@ import {
 	unregister,
 } from '../lib/translation.ts'
 
-const setLocale = (locale: string) => { globalThis._nc_l10n_locale = locale }
-const setLanguage = (lang: string) => { globalThis._nc_l10n_language = lang }
-
 describe('translate', () => {
 	const mockWindowDE = () => {
 		globalThis._oc_l10n_registry_translations = {