feat(cli): add Traditional Chinese (zh-TW) as a UI language option

packages/cli/src/i18n/index.ts

@@ -57,15 +57,18 @@ const getLocalePath = (
 export function detectSystemLanguage(): SupportedLanguage {
   const envLang = process.env['QWEN_CODE_LANG'] || process.env['LANG'];
   if (envLang) {
+    // Normalize POSIX locales (e.g. zh_TW.UTF-8 → zh-tw) before matching
+    const normalized = envLang.replace(/_/g, '-').toLowerCase();
     for (const lang of SUPPORTED_LANGUAGES) {
-      if (envLang.startsWith(lang.code)) return lang.code;
+      if (normalized.startsWith(lang.code.toLowerCase())) return lang.code;
     }
   }
 
   try {
     const locale = Intl.DateTimeFormat().resolvedOptions().locale;
+    const normalized = locale.replace(/_/g, '-').toLowerCase();
     for (const lang of SUPPORTED_LANGUAGES) {
-      if (locale.startsWith(lang.code)) return lang.code;
+      if (normalized.startsWith(lang.code.toLowerCase())) return lang.code;
     }
   } catch {
     // Fallback to default

packages/cli/src/i18n/languages.ts

@@ -7,6 +7,7 @@
 export type SupportedLanguage =
   | 'en'
   | 'zh'
+  | 'zh-TW'
   | 'ru'
   | 'de'
   | 'ja'
@@ -32,6 +33,12 @@ export const SUPPORTED_LANGUAGES: readonly LanguageDefinition[] = [
     fullName: 'English',
     nativeName: 'English',
   },
+  {
+    code: 'zh-TW',
+    id: 'zh-TW',
+    fullName: 'Traditional Chinese',
+    nativeName: '繁體中文',
+  },
   {
     code: 'zh',
     id: 'zh-CN',
@@ -75,7 +82,8 @@ export const SUPPORTED_LANGUAGES: readonly LanguageDefinition[] = [
  * Used for LLM output language instructions.
  */
 export function getLanguageNameFromLocale(locale: SupportedLanguage): string {
-  const lang = SUPPORTED_LANGUAGES.find((l) => l.code === locale);
+  const lower = locale.toLowerCase();
+  const lang = SUPPORTED_LANGUAGES.find((l) => l.code.toLowerCase() === lower);
   return lang?.fullName || 'English';
 }
 

packages/cli/src/ui/hooks/usePhraseCycler.ts

@@ -5,7 +5,7 @@
  */
 
 import { useState, useEffect, useRef, useMemo } from 'react';
-import { t, ta } from '../../i18n/index.js';
+import { t, ta, getCurrentLanguage } from '../../i18n/index.js';
 
 export const WITTY_LOADING_PHRASES: string[] = ["I'm Feeling Lucky"];
 
@@ -23,6 +23,7 @@ export const usePhraseCycler = (
   customPhrases?: string[],
 ) => {
   // Get phrases from translations if available
+  const currentLanguage = getCurrentLanguage();
   const loadingPhrases = useMemo(() => {
     if (customPhrases && customPhrases.length > 0) {
       return customPhrases;
@@ -31,7 +32,8 @@ export const usePhraseCycler = (
     return translatedPhrases.length > 0
       ? translatedPhrases
       : WITTY_LOADING_PHRASES;
-  }, [customPhrases]);
+    // eslint-disable-next-line react-hooks/exhaustive-deps
+  }, [customPhrases, currentLanguage]);
 
   const [currentLoadingPhrase, setCurrentLoadingPhrase] = useState(
     loadingPhrases[0],

packages/cli/src/utils/languageUtils.test.ts

@@ -22,6 +22,7 @@ vi.mock('../i18n/index.js', () => ({
   getLanguageNameFromLocale: vi.fn((locale: string) => {
     const map: Record<string, string> = {
       en: 'English',
+      'zh-tw': 'Traditional Chinese',
       zh: 'Chinese',
       ru: 'Russian',
       de: 'German',
@@ -30,7 +31,7 @@ vi.mock('../i18n/index.js', () => ({
       fr: 'French',
       es: 'Spanish',
     };
-    return map[locale] || 'English';
+    return map[locale.toLowerCase()] || 'English';
   }),
 }));
 
@@ -123,6 +124,12 @@ describe('languageUtils', () => {
       expect(normalizeOutputLanguage('Ru')).toBe('Russian');
     });
 
+    it('should convert "zh-TW" (mixed case) to "Traditional Chinese"', () => {
+      expect(normalizeOutputLanguage('zh-TW')).toBe('Traditional Chinese');
+      expect(normalizeOutputLanguage('zh-tw')).toBe('Traditional Chinese');
+      expect(normalizeOutputLanguage('ZH-TW')).toBe('Traditional Chinese');
+    });
+
     it('should preserve explicit language names as-is', () => {
       expect(normalizeOutputLanguage('Japanese')).toBe('Japanese');
       expect(normalizeOutputLanguage('French')).toBe('French');

packages/core/src/core/loggingContentGenerator/loggingContentGenerator.test.ts

@@ -405,11 +405,8 @@ describe('LoggingContentGenerator', () => {
 
   it('uses generator modalities when converting logged OpenAI requests', async () => {
     convertGeminiRequestToOpenAISpy.mockImplementationOnce(
-      (request, requestContext, options) => realConvertGeminiRequestToOpenAI(
-          request,
-          requestContext,
-          options,
-        ),
+      (request, requestContext, options) =>
+        realConvertGeminiRequestToOpenAI(request, requestContext, options),
     );
 
     const wrapped = createWrappedGenerator(

packages/core/src/qwen/qwenOAuth2.ts

@@ -489,10 +489,10 @@ export enum QwenOAuth2Event {
 export type AuthResult =
   | { success: true }
   | {
-    success: false;
-    reason: 'timeout' | 'cancelled' | 'error' | 'rate_limit';
-    message?: string; // Detailed error message for better error reporting
-  };
+      success: false;
+      reason: 'timeout' | 'cancelled' | 'error' | 'rate_limit';
+      message?: string; // Detailed error message for better error reporting
+    };
 
 /**
  * Global event emitter instance for QwenOAuth2 authentication events
@@ -731,13 +731,14 @@ async function authWithQwenDeviceFlow(
           debugLogger.info(`Please open this URL manually: ${url}`);
         });
 
-        // Optional: Also listen for 'close' or 'exit' if needed for cleanup, 
+        // Optional: Also listen for 'close' or 'exit' if needed for cleanup,
         // but 'error' is the main crasher.
       } else {
         // Fallback: If open() didn't return a valid process object, log a warning
-        debugLogger.debug('open() did not return a valid child process object.');
+        debugLogger.debug(
+          'open() did not return a valid child process object.',
+        );
       }
-
     } catch (err) {
       // Handle synchronous errors or promise rejections from open()
       const errorMessage = err instanceof Error ? err.message : String(err);

packages/vscode-ide-companion/schemas/settings.schema.json

@@ -83,10 +83,11 @@
           "default": false
         },
         "language": {
-          "description": "The language for the user interface. Use \"auto\" to detect from system settings. You can also use custom language codes (e.g., \"es\", \"fr\") by placing JS language files in ~/.qwen/locales/ (e.g., ~/.qwen/locales/es.js). Options: auto, en, zh, ru, de, ja, pt, fr",
+          "description": "The language for the user interface. Use \"auto\" to detect from system settings. You can also use custom language codes (e.g., \"es\", \"fr\") by placing JS language files in ~/.qwen/locales/ (e.g., ~/.qwen/locales/es.js). Options: auto, en, zh-TW, zh, ru, de, ja, pt, fr",
           "enum": [
             "auto",
             "en",
+            "zh-TW",
             "zh",
             "ru",
             "de",

scripts/check-i18n.ts

@@ -13,7 +13,6 @@ import { fileURLToPath } from 'url';
 import { dirname } from 'path';
 
 // Get __dirname for ESM modules
-// @ts-expect-error - import.meta is supported in NodeNext module system at runtime
 const __dirname = dirname(fileURLToPath(import.meta.url));
 
 interface CheckResult {
@@ -23,6 +22,7 @@ interface CheckResult {
   stats: {
     totalKeys: number;
     translatedKeys: number;
+    zhTWTranslatedKeys: number;
     unusedKeys: string[];
     unusedKeysOnlyInLocales?: string[]; // 新增：只在 locales 中存在的未使用键
   };
@@ -172,27 +172,31 @@ function checkKeyValueConsistency(
 }
 
 /**
- * Check if en.js and zh.js have matching keys
+ * Check if locale files have matching keys with en.js
+ * @param enTranslations The en.js translations
+ * @param localeTranslations The target locale translations (zh.js or zh-TW.js)
+ * @param localeLabel Label for diagnostics (e.g., "zh.js" or "zh-TW.js")
  */
 function checkKeyMatching(
   enTranslations: Record<string, string | string[]>,
-  zhTranslations: Record<string, string | string[]>,
+  localeTranslations: Record<string, string | string[]>,
+  localeLabel: string,
 ): string[] {
   const errors: string[] = [];
   const enKeys = new Set(Object.keys(enTranslations));
-  const zhKeys = new Set(Object.keys(zhTranslations));
+  const localeKeys = new Set(Object.keys(localeTranslations));
 
-  // Check for keys in en but not in zh
+  // Check for keys in en but not in locale
   for (const key of enKeys) {
-    if (!zhKeys.has(key)) {
-      errors.push(`Missing translation in zh.js: "${key}"`);
+    if (!localeKeys.has(key)) {
+      errors.push(`Missing translation in ${localeLabel}: "${key}"`);
     }
   }
 
-  // Check for keys in zh but not in en
-  for (const key of zhKeys) {
+  // Check for keys in locale but not in en
+  for (const key of localeKeys) {
     if (!enKeys.has(key)) {
-      errors.push(`Extra key in zh.js (not in en.js): "${key}"`);
+      errors.push(`Extra key in ${localeLabel} (not in en.js): "${key}"`);
     }
   }
 
@@ -304,10 +308,12 @@ async function checkI18n(): Promise<CheckResult> {
 
   const enPath = path.join(localesDir, 'en.js');
   const zhPath = path.join(localesDir, 'zh.js');
+  const zhTWPath = path.join(localesDir, 'zh-TW.js');
 
   // Load translation files
   let enTranslations: Record<string, string | string[]>;
   let zhTranslations: Record<string, string | string[]>;
+  let zhTWTranslations: Record<string, string | string[]>;
 
   try {
     enTranslations = await loadTranslationsFile(enPath);
@@ -319,7 +325,12 @@ async function checkI18n(): Promise<CheckResult> {
       success: false,
       errors,
       warnings,
-      stats: { totalKeys: 0, translatedKeys: 0, unusedKeys: [] },
+      stats: {
+        totalKeys: 0,
+        translatedKeys: 0,
+        zhTWTranslatedKeys: 0,
+        unusedKeys: [],
+      },
     };
   }
 
@@ -333,7 +344,31 @@ async function checkI18n(): Promise<CheckResult> {
       success: false,
       errors,
       warnings,
-      stats: { totalKeys: 0, translatedKeys: 0, unusedKeys: [] },
+      stats: {
+        totalKeys: 0,
+        translatedKeys: 0,
+        zhTWTranslatedKeys: 0,
+        unusedKeys: [],
+      },
+    };
+  }
+
+  try {
+    zhTWTranslations = await loadTranslationsFile(zhTWPath);
+  } catch (error) {
+    errors.push(
+      `Failed to load zh-TW.js: ${error instanceof Error ? error.message : String(error)}`,
+    );
+    return {
+      success: false,
+      errors,
+      warnings,
+      stats: {
+        totalKeys: 0,
+        translatedKeys: 0,
+        zhTWTranslatedKeys: 0,
+        unusedKeys: [],
+      },
     };
   }
 
@@ -342,9 +377,21 @@ async function checkI18n(): Promise<CheckResult> {
   errors.push(...consistencyErrors);
 
   // Check key matching between en and zh
-  const matchingErrors = checkKeyMatching(enTranslations, zhTranslations);
+  const matchingErrors = checkKeyMatching(
+    enTranslations,
+    zhTranslations,
+    'zh.js',
+  );
   errors.push(...matchingErrors);
 
+  // Check key matching between en and zh-TW
+  const matchingTWErrors = checkKeyMatching(
+    enTranslations,
+    zhTWTranslations,
+    'zh-TW.js',
+  );
+  errors.push(...matchingTWErrors);
+
   // Extract used keys from source code
   const usedKeys = await extractUsedKeys(sourceDir);
 
@@ -363,15 +410,17 @@ async function checkI18n(): Promise<CheckResult> {
   }
 
   const totalKeys = Object.keys(enTranslations).length;
-  const translatedKeys = Object.keys(zhTranslations).length;
+  const zhTranslatedKeys = Object.keys(zhTranslations).length;
+  const zhTWTranslatedKeys = Object.keys(zhTWTranslations).length;
 
   return {
     success: errors.length === 0,
     errors,
     warnings,
     stats: {
       totalKeys,
-      translatedKeys,
+      translatedKeys: zhTranslatedKeys,
+      zhTWTranslatedKeys,
       unusedKeys,
       unusedKeysOnlyInLocales,
     },

scripts/unused-keys-only-in-locales.json

@@ -1,5 +1,5 @@
 {
-  "generatedAt": "2026-04-22T15:40:32.318Z",
+  "generatedAt": "2026-04-24T07:06:13.173Z",
   "keys": [
     "  Models: Qwen latest models\n",
     "  qwen auth qwen-oauth     - Authenticate with Qwen OAuth (discontinued)",