feat: localize WORKING_DIR_NOT_FOUND SSE errors

src/__tests__/unit/use-sse-stream.test.ts

@@ -0,0 +1,96 @@
+import { afterEach, describe, it } from 'node:test';
+import assert from 'node:assert/strict';
+
+import { consumeSSEStream, formatSSEError } from '../../hooks/useSSEStream';
+
+describe('formatSSEError', () => {
+  const originalNavigator = globalThis.navigator;
+
+  afterEach(() => {
+    if (originalNavigator) {
+      Object.defineProperty(globalThis, 'navigator', {
+        value: originalNavigator,
+        configurable: true,
+      });
+    } else {
+      Reflect.deleteProperty(globalThis, 'navigator');
+    }
+  });
+
+  it('should localize structured working directory errors with provided translator', () => {
+    const formatted = formatSSEError(
+      JSON.stringify({
+        error_code: 'WORKING_DIR_NOT_FOUND',
+        working_directory: '/tmp/demo',
+      }),
+      (key, params) => `${key}:${params?.dir}`
+    );
+
+    assert.equal(formatted, 'error.workingDirNotFound:/tmp/demo');
+  });
+
+  it('should fall back to locale detection when translator is omitted', () => {
+    Object.defineProperty(globalThis, 'navigator', {
+      value: { language: 'zh-CN' },
+      configurable: true,
+    });
+
+    const formatted = formatSSEError(
+      JSON.stringify({
+        error_code: 'WORKING_DIR_NOT_FOUND',
+        working_directory: '/tmp/demo',
+      })
+    );
+
+    assert.equal(formatted, '项目目录不存在：/tmp/demo');
+  });
+
+  it('should return plain error text unchanged', () => {
+    assert.equal(formatSSEError('plain error text'), 'plain error text');
+  });
+});
+
+describe('consumeSSEStream', () => {
+  it('should localize structured error events in the full consume path', async () => {
+    const encoder = new TextEncoder();
+    let errorText = '';
+
+    const stream = new ReadableStream<Uint8Array>({
+      start(controller) {
+        controller.enqueue(
+          encoder.encode(
+            `data: ${JSON.stringify({
+              type: 'error',
+              data: JSON.stringify({
+                error_code: 'WORKING_DIR_NOT_FOUND',
+                working_directory: '/tmp/project',
+              }),
+            })}\n\n`
+          )
+        );
+        controller.close();
+      },
+    });
+
+    const result = await consumeSSEStream(stream.getReader(), {
+      onText: () => {},
+      onToolUse: () => {},
+      onToolResult: () => {},
+      onToolOutput: () => {},
+      onToolProgress: () => {},
+      onStatus: () => {},
+      onResult: () => {},
+      onPermissionRequest: () => {},
+      onToolTimeout: () => {},
+      onModeChanged: () => {},
+      onTaskUpdate: () => {},
+      onKeepAlive: () => {},
+      onError: (accumulated) => {
+        errorText = accumulated;
+      },
+    }, (key, params) => `${key}:${params?.dir}`);
+
+    assert.equal(errorText, '\n\n**Error:** error.workingDirNotFound:/tmp/project');
+    assert.equal(result.accumulated, '\n\n**Error:** error.workingDirNotFound:/tmp/project');
+  });
+});

src/app/chat/page.tsx

@@ -6,6 +6,8 @@ import type { Message, SSEEvent, SessionResponse, TokenUsage, PermissionRequestE
 import { MessageList } from '@/components/chat/MessageList';
 import { MessageInput } from '@/components/chat/MessageInput';
 import { usePanel } from '@/hooks/usePanel';
+import { formatSSEError } from '@/hooks/useSSEStream';
+import { useTranslation } from '@/hooks/useTranslation';
 
 interface ToolUseInfo {
   id: string;
@@ -20,14 +22,15 @@ interface ToolResultInfo {
 
 export default function NewChatPage() {
   const router = useRouter();
-  const { setWorkingDirectory, setPanelOpen, setPendingApprovalSessionId } = usePanel();
+  const { setPendingApprovalSessionId } = usePanel();
+  const { t } = useTranslation();
   const [messages, setMessages] = useState<Message[]>([]);
   const [streamingContent, setStreamingContent] = useState('');
   const [isStreaming, setIsStreaming] = useState(false);
   const [toolUses, setToolUses] = useState<ToolUseInfo[]>([]);
   const [toolResults, setToolResults] = useState<ToolResultInfo[]>([]);
   const [statusText, setStatusText] = useState<string | undefined>();
-  const [workingDir, setWorkingDir] = useState('');
+  const [workingDir] = useState('');
   const [mode, setMode] = useState('code');
   const [currentModel, setCurrentModel] = useState('sonnet');
   const [currentProviderId, setCurrentProviderId] = useState('');
@@ -252,7 +255,7 @@ export default function NewChatPage() {
                   break;
                 }
                 case 'error': {
-                  accumulated += '\n\n**Error:** ' + event.data;
+                  accumulated += '\n\n**Error:** ' + formatSSEError(event.data, t);
                   setStreamingContent(accumulated);
                   break;
                 }
@@ -311,7 +314,7 @@ export default function NewChatPage() {
         abortControllerRef.current = null;
       }
     },
-    [isStreaming, router, workingDir, mode, currentModel, currentProviderId, setPendingApprovalSessionId]
+    [isStreaming, router, workingDir, mode, currentModel, currentProviderId, setPendingApprovalSessionId, t]
   );
 
   const handleCommand = useCallback((command: string) => {

src/components/layout/I18nProvider.tsx

@@ -1,7 +1,7 @@
 'use client';
 
 import { createContext, useState, useEffect, useCallback, type ReactNode } from 'react';
-import { type Locale, type TranslationKey, translate } from '@/i18n';
+import { type Locale, type TranslationKey, translate, setCurrentLocale } from '@/i18n';
 
 interface I18nContextValue {
   locale: Locale;
@@ -37,6 +37,10 @@ export function I18nProvider({ children }: { children: ReactNode }) {
     loadLocale();
   }, []);
 
+  useEffect(() => {
+    setCurrentLocale(locale);
+  }, [locale]);
+
   const setLocale = useCallback((newLocale: Locale) => {
     setLocaleState(newLocale);
     // Persist to app settings

src/hooks/useSSEStream.ts

@@ -1,5 +1,23 @@
 import { useRef, useCallback } from 'react';
 import type { SSEEvent, TokenUsage, PermissionRequestEvent } from '@/types';
+import { translate, detectLocale, type TranslationKey } from '@/i18n';
+
+export type TranslationFn = (key: TranslationKey, params?: Record<string, string | number>) => string;
+
+export function formatSSEError(eventData: string, t?: TranslationFn): string {
+  try {
+    const parsed = JSON.parse(eventData);
+    if (parsed.error_code === 'WORKING_DIR_NOT_FOUND') {
+      const translator = t ?? ((key: TranslationKey, params?: Record<string, string | number>) =>
+        translate(detectLocale(), key, params));
+      return translator('error.workingDirNotFound', { dir: parsed.working_directory });
+    }
+  } catch {
+    // ignore
+  }
+
+  return eventData;
+}
 
 interface ToolUseInfo {
   id: string;
@@ -36,6 +54,7 @@ function handleSSEEvent(
   event: SSEEvent,
   accumulated: string,
   callbacks: SSECallbacks,
+  t?: TranslationFn,
 ): string {
   switch (event.type) {
     case 'text': {
@@ -153,7 +172,7 @@ function handleSSEEvent(
     }
 
     case 'error': {
-      const next = accumulated + '\n\n**Error:** ' + event.data;
+      const next = accumulated + '\n\n**Error:** ' + formatSSEError(event.data, t);
       callbacks.onError(next);
       return next;
     }
@@ -174,6 +193,7 @@ function handleSSEEvent(
 export async function consumeSSEStream(
   reader: ReadableStreamDefaultReader<Uint8Array>,
   callbacks: SSECallbacks,
+  t?: TranslationFn,
 ): Promise<{ accumulated: string; tokenUsage: TokenUsage | null }> {
   const decoder = new TextDecoder();
   let buffer = '';
@@ -201,7 +221,7 @@ export async function consumeSSEStream(
 
       try {
         const event: SSEEvent = JSON.parse(line.slice(6));
-        accumulated = handleSSEEvent(event, accumulated, wrappedCallbacks);
+        accumulated = handleSSEEvent(event, accumulated, wrappedCallbacks, t);
       } catch {
         // skip malformed SSE lines
       }
@@ -222,6 +242,7 @@ export function useSSEStream() {
     async (
       reader: ReadableStreamDefaultReader<Uint8Array>,
       callbacks: SSECallbacks,
+      t?: TranslationFn,
     ) => {
       callbacksRef.current = callbacks;
 
@@ -242,7 +263,7 @@ export function useSSEStream() {
         onError: (a) => callbacksRef.current?.onError(a),
       };
 
-      return consumeSSEStream(reader, proxied);
+      return consumeSSEStream(reader, proxied, t);
     },
     [],
   );

src/i18n/en.ts

@@ -331,6 +331,7 @@ const en = {
   'error.hideDetails': 'Hide details',
   'error.tryAgain': 'Try Again',
   'error.reloadApp': 'Reload App',
+  'error.workingDirNotFound': 'Project directory not found: {dir}',
 
   // ── Update ─────────────────────────────────────────────────
   'update.newVersionAvailable': 'New Version Available',

src/i18n/index.ts

@@ -5,6 +5,8 @@ export type { TranslationKey };
 
 export type Locale = 'en' | 'zh';
 
+let currentLocale: Locale | null = null;
+
 export const SUPPORTED_LOCALES: { value: Locale; label: string }[] = [
   { value: 'en', label: 'English' },
   { value: 'zh', label: '中文' },
@@ -15,6 +17,16 @@ const dictionaries: Record<Locale, Record<TranslationKey, string>> = {
   zh,
 };
 
+export function setCurrentLocale(locale: Locale): void {
+  currentLocale = locale;
+}
+
+export function detectLocale(): Locale {
+  if (currentLocale) return currentLocale;
+  if (typeof navigator !== 'undefined' && navigator.language.startsWith('zh')) return 'zh';
+  return 'en';
+}
+
 /**
  * Translate a key with optional parameter interpolation.
  * Fallback chain: target locale → English → raw key.

src/i18n/zh.ts

@@ -328,6 +328,7 @@ const zh: Record<TranslationKey, string> = {
   'error.hideDetails': '隐藏详情',
   'error.tryAgain': '重试',
   'error.reloadApp': '重新加载',
+  'error.workingDirNotFound': '项目目录不存在：{dir}',
 
   // ── Update ─────────────────────────────────────────────────
   'update.newVersionAvailable': '有新版本可用',

src/lib/claude-client.ts

@@ -1,6 +1,5 @@
 import { query } from '@anthropic-ai/claude-agent-sdk';
 import type {
-  SDKMessage,
   SDKAssistantMessage,
   SDKUserMessage,
   SDKResultMessage,
@@ -31,7 +30,6 @@ import path from 'path';
  * Removes null bytes and control characters that cause spawn EINVAL.
  */
 function sanitizeEnvValue(value: string): string {
-  // eslint-disable-next-line no-control-regex
   return value.replace(/[\x00-\x08\x0B\x0C\x0E-\x1F\x7F]/g, '');
 }
 
@@ -165,19 +163,6 @@ function formatSSE(event: SSEEvent): string {
   return `data: ${JSON.stringify(event)}\n\n`;
 }
 
-/**
- * Extract text content from an SDK assistant message
- */
-function extractTextFromMessage(msg: SDKAssistantMessage): string {
-  const parts: string[] = [];
-  for (const block of msg.message.content) {
-    if (block.type === 'text') {
-      parts.push(block.text);
-    }
-  }
-  return parts.join('');
-}
-
 /**
  * Extract token usage from an SDK result message
  */
@@ -363,6 +348,20 @@ export function streamClaude(options: ClaudeStreamOptions): ReadableStream<strin
           }
         }
 
+        if (workingDirectory && !fs.existsSync(workingDirectory)) {
+          controller.enqueue(formatSSE({
+            type: 'error',
+            data: JSON.stringify({
+              error_code: 'WORKING_DIR_NOT_FOUND',
+              message: `Project directory not found: ${workingDirectory}`,
+              working_directory: workingDirectory,
+            }),
+          }));
+          controller.enqueue(formatSSE({ type: 'done', data: '' }));
+          controller.close();
+          return;
+        }
+
         // Check if dangerously_skip_permissions is enabled in app settings
         const skipPermissions = getSetting('dangerously_skip_permissions') === 'true';
 
@@ -730,7 +729,6 @@ export function streamClaude(options: ClaudeStreamOptions): ReadableStream<strin
 
         registerConversation(sessionId, conversation);
 
-        let lastAssistantText = '';
         let tokenUsage: TokenUsage | null = null;
 
         for await (const message of conversation) {
@@ -742,11 +740,6 @@ export function streamClaude(options: ClaudeStreamOptions): ReadableStream<strin
             case 'assistant': {
               const assistantMsg = message as SDKAssistantMessage;
               // Text deltas are handled by stream_event for real-time streaming.
-              // Only track lastAssistantText here and process tool_use blocks.
-              const text = extractTextFromMessage(assistantMsg);
-              if (text) {
-                lastAssistantText = text;
-              }
 
               // Check for tool use blocks
               for (const block of assistantMsg.message.content) {
@@ -906,7 +899,15 @@ export function streamClaude(options: ClaudeStreamOptions): ReadableStream<strin
         if (error instanceof Error) {
           const code = (error as NodeJS.ErrnoException).code;
           if (code === 'ENOENT' || rawMessage.includes('ENOENT') || rawMessage.includes('spawn')) {
-            errorMessage = `Claude Code CLI not found. Please ensure Claude Code is installed and available in your PATH.\n\nOriginal error: ${rawMessage}`;
+            if (workingDirectory && !fs.existsSync(workingDirectory)) {
+              errorMessage = JSON.stringify({
+                error_code: 'WORKING_DIR_NOT_FOUND',
+                message: `Project directory not found: ${workingDirectory}`,
+                working_directory: workingDirectory,
+              });
+            } else {
+              errorMessage = `Claude Code CLI not found. Please ensure Claude Code is installed and available in your PATH.\n\nOriginal error: ${rawMessage}`;
+            }
           } else if (rawMessage.includes('exited with code 1') || rawMessage.includes('exit code 1')) {
             const providerHint = activeProvider?.name ? ` (Provider: ${activeProvider.name})` : '';
             const detailHint = extraDetail ? `\n\nDetails: ${extraDetail}` : '';