No longer map zh_TW language to zh language code in dev translations.

.changelog/20260721132553_ck_10480.md

@@ -0,0 +1,15 @@
+---
+type: Major breaking change
+scope:
+  - ckeditor5-dev-translations
+see:
+  - https://github.com/ckeditor/ckeditor5-commercial/issues/10480
+---
+
+The `zh_CN` and `zh_TW` locale codes have been replaced with `zh_Hans` and `zh_Hant`, respectively, to correctly represent Simplified and Traditional Chinese as script variants instead of country/region variants.
+
+As a result:
+
+* The `zh_TW` language code is no longer mapped to the `zh.po` file. It now emits `zh-hant.po` instead.
+* The `zh_CN` language code now emits `zh-hans.po` instead of `zh-cn.po`.
+* The `languageCode` for these locales changed from `zh` (for both) to `zh-Hans` and `zh-Hant`, respectively.

packages/ckeditor5-dev-translations/lib/utils/getlanguages.js

@@ -17,8 +17,8 @@ const SUPPORTED_LOCALES = [
 	'bs', // Bosnian
 	'bg', // Bulgarian
 	'ca', // Catalan
-	'zh_CN', // Chinese (China)
-	'zh_TW', // Chinese (Taiwan)
+	'zh@hans', // Chinese (Simplified)
+	'zh@hant', // Chinese (Traditional)
 	'hr', // Croatian
 	'cs', // Czech
 	'da', // Danish
@@ -78,12 +78,12 @@ const SUPPORTED_LOCALES = [
 	'uz', // Uzbek
 	'vi' // Vietnamese
 ];
-
 const LOCALES_FILENAME_MAP = {
 	'ne_NP': 'ne',
 	'si_LK': 'si',
 	'sr@latin': 'sr-latn',
-	'zh_TW': 'zh'
+	'zh@hans': 'zh-hans',
+	'zh@hant': 'zh-hant'
 };
 
 /**

packages/ckeditor5-dev-translations/tests/utils/getlanguages.js

@@ -57,12 +57,12 @@ describe( 'getLanguages()', () => {
 
 	it( 'should use predefined filename if defined', () => {
 		const languages = getLanguages();
-		const languageChineseTaiwan = languages.find( l => l.localeCode === 'zh_TW' );
+		const languageChineseTaiwan = languages.find( l => l.localeCode === 'zh@hans' );
 
 		expect( languageChineseTaiwan ).toEqual( {
-			localeCode: 'zh_TW',
+			localeCode: 'zh@hans',
 			languageCode: 'zh',
-			languageFileName: 'zh'
+			languageFileName: 'zh-hans'
 		} );
 	} );
 } );