fix: Standardize locale codes and warn about unsupported ones (#1617)

packages/i18n/src/__tests__/utils.test.ts

@@ -1,10 +1,14 @@
 import { describe, it, expect } from 'vitest';
 import { ChromeMessage } from '../build';
-import { applyChromeMessagePlaceholders, getSubstitutionCount } from '../utils';
+import {
+  applyChromeMessagePlaceholders,
+  getSubstitutionCount,
+  standardizeLocale,
+} from '../utils';
 
 describe('Utils', () => {
   describe('applyChromeMessagePlaceholders', () => {
-    it('should return the combined stirng', () => {
+    it('should return the combined string', () => {
       const input = {
         message: 'Hello $username$, welcome to $appName$',
         placeholders: {
@@ -60,4 +64,30 @@ describe('Utils', () => {
       expect(getSubstitutionCount('Hello $10')).toBe(1);
     });
   });
+
+  describe('standardizeLocale', () => {
+    it('should convert two-letter locale codes to lowercase', () => {
+      expect(standardizeLocale('en')).toEqual('en');
+      expect(standardizeLocale('EN')).toEqual('en');
+    });
+
+    it('should convert locale code extensions to uppercase', () => {
+      expect(standardizeLocale('en_US')).toEqual('en_US');
+      expect(standardizeLocale('en_us')).toEqual('en_US');
+      expect(standardizeLocale('es_419')).toEqual('es_419');
+    });
+
+    it('should convert dashes to underscores', () => {
+      expect(standardizeLocale('en_US')).toEqual('en_US');
+      expect(standardizeLocale('en-US')).toEqual('en_US');
+    });
+
+    it('should return the input string as-is for unknown formats', () => {
+      expect(standardizeLocale('en_USSS')).toEqual('en_USSS');
+      expect(standardizeLocale('en-')).toEqual('en-');
+      expect(standardizeLocale('------')).toEqual('------');
+      expect(standardizeLocale('test')).toEqual('test');
+      expect(standardizeLocale('hello-world')).toEqual('hello-world');
+    });
+  });
 });

packages/i18n/src/build.ts

@@ -10,6 +10,8 @@ import { parseYAML, parseJSON5, parseTOML } from 'confbox';
 import { dirname, extname } from 'node:path';
 import { applyChromeMessagePlaceholders, getSubstitutionCount } from './utils';
 
+export { SUPPORTED_LOCALES } from './supported-locales';
+
 //
 // TYPES
 //

packages/i18n/src/module.ts

@@ -16,12 +16,14 @@ import {
   generateChromeMessagesText,
   parseMessagesFile,
   generateTypeText,
+  SUPPORTED_LOCALES,
 } from './build';
 import glob from 'fast-glob';
 import { basename, extname, join, resolve } from 'node:path';
 import { watch } from 'chokidar';
 import { GeneratedPublicFile, WxtDirFileEntry } from 'wxt';
 import { writeFile } from 'node:fs/promises';
+import { standardizeLocale } from './utils';
 
 export default defineWxtModule<I18nOptions>({
   name: '@wxt-dev/i18n',
@@ -46,10 +48,22 @@ export default defineWxtModule<I18nOptions>({
         cwd: localesDir,
         absolute: true,
       });
-      return files.map((file) => ({
-        file,
-        locale: basename(file).replace(extname(file), ''),
-      }));
+
+      const unsupportedLocales: string[] = [];
+
+      const res = files.map((file) => {
+        const rawLocale = basename(file).replace(extname(file), '');
+        const locale = standardizeLocale(rawLocale);
+        if (!SUPPORTED_LOCALES.has(locale)) unsupportedLocales.push(locale);
+        return { file, locale };
+      });
+
+      if (unsupportedLocales.length > 0)
+        wxt.logger.warn(
+          `Unsupported locales: [${unsupportedLocales.join(', ')}].\n\nWeb extensions only support a limited set of locales as described here: https://developer.chrome.com/docs/extensions/reference/api/i18n#locales`,
+        );
+
+      return res;
     };
 
     const generateOutputJsonFiles = async (): Promise<

packages/i18n/src/supported-locales.ts

@@ -0,0 +1,58 @@
+/** From https://developer.chrome.com/docs/extensions/reference/api/i18n#locales */
+export const SUPPORTED_LOCALES = new Set([
+  'ar',
+  'am',
+  'bg',
+  'bn',
+  'ca',
+  'cs',
+  'da',
+  'de',
+  'el',
+  'en',
+  'en_AU',
+  'en_GB',
+  'en_US',
+  'es',
+  'es_419',
+  'et',
+  'fa',
+  'fi',
+  'fil',
+  'fr',
+  'gu',
+  'he',
+  'hi',
+  'hr',
+  'hu',
+  'id',
+  'it',
+  'ja',
+  'kn',
+  'ko',
+  'lt',
+  'lv',
+  'ml',
+  'mr',
+  'ms',
+  'nl',
+  'no',
+  'pl',
+  'pt_BR',
+  'pt_PT',
+  'ro',
+  'ru',
+  'sk',
+  'sl',
+  'sr',
+  'sv',
+  'sw',
+  'ta',
+  'te',
+  'th',
+  'tr',
+  'uk',
+  'vi',
+  'zh_CN',
+  'zh_TW',
+]);

packages/i18n/src/utils.ts

@@ -21,3 +21,16 @@ export function getSubstitutionCount(message: string): number {
 }
 
 const MAX_SUBSTITUTIONS = 9;
+
+/** Given a string, standardize it to the format `xx_YY`. */
+export function standardizeLocale(locale: string): string {
+  if (locale.length === 2) return locale.toLowerCase();
+
+  const [is_match, prefix, suffix] =
+    locale.match(/^([a-z]{2})[-_]([a-z]{2,3})$/i) ?? [];
+  if (is_match) {
+    return `${prefix.toLowerCase()}_${suffix.toUpperCase()}`;
+  }
+
+  return locale;
+}