fix(cli): preserve Unicode queries in at completion (#13866)

docs/users/features/commands.md

@@ -522,6 +522,8 @@ Use `/auth` inside a Qwen Code session to configure authentication. Use `/doctor
 
 Note: Spaces in paths need to be escaped with backslash (e.g., `@My\ Documents/file.txt`)
 
+In the interactive prompt, `@` completion supports Unicode filenames, including emoji. Emoji elsewhere in the prompt do not change the file path used for completion.
+
 ## 3. Exclamation Commands (`!`) - Shell Command Execution
 
 Exclamation commands allow you to execute system commands directly within Qwen Code.

packages/cli/src/ui/hooks/useCommandCompletion.test.ts

@@ -487,6 +487,61 @@ describe('useCommandCompletion', () => {
   });
 
   describe('Completion mode detection', () => {
+    it.each([
+      ['hello @README.md', 'README.md'],
+      ['中文 @文件.ts', '文件.ts'],
+      ['😀 @README.md', 'README.md'],
+      ['@😀file.ts', '😀file.ts'],
+      ['😀😀 @src/𠮷file.ts', 'src/𠮷file.ts'],
+      ['😀 @src/😀file.ts', 'src/😀file.ts'],
+    ])('uses the complete file query from %s', (text, pattern) => {
+      renderHook(() =>
+        useCommandCompletion(
+          useTextBufferForTest(text, Array.from(text).length),
+          testRootDir,
+          [],
+          mockCommandContext,
+          false,
+          mockConfig,
+        ),
+      );
+
+      expect(useAtCompletion).toHaveBeenLastCalledWith(
+        expect.objectContaining({ enabled: true, pattern }),
+      );
+    });
+
+    it('keeps code-point replacement bounds with the cursor inside a Unicode path', async () => {
+      setupMocks({
+        atSuggestions: [{ label: '😀done.ts', value: '😀done.ts' }],
+      });
+      const { result } = renderHook(() => {
+        const textBuffer = useTextBufferForTest('😀 @src/😀file.ts tail', 7);
+        const completion = useCommandCompletion(
+          textBuffer,
+          testRootDir,
+          [],
+          mockCommandContext,
+          false,
+          mockConfig,
+        );
+        return { ...completion, textBuffer };
+      });
+
+      expect(useAtCompletion).toHaveBeenLastCalledWith(
+        expect.objectContaining({ enabled: true, pattern: 'src/😀file.ts' }),
+      );
+      await waitFor(() => {
+        expect(result.current.suggestions).toHaveLength(1);
+      });
+
+      act(() => {
+        result.current.handleAutocomplete(0);
+      });
+
+      expect(result.current.textBuffer.text).toBe('😀 @😀done.ts tail');
+    });
+
     it('should switch to AT mode when typing @ after a slash command (#2518)', async () => {
       setupMocks({
         atSuggestions: [{ label: 'src/file.txt', value: 'src/file.txt' }],

packages/cli/src/ui/hooks/useCommandCompletion.tsx

@@ -143,7 +143,7 @@ export function useCommandCompletion(
           }
         }
         const pathStart = i + 1;
-        const partialPath = currentLine.substring(pathStart, end);
+        const partialPath = codePoints.slice(pathStart, end).join('');
         return {
           completionMode: CompletionMode.AT,
           query: partialPath,

packages/cli/src/ui/opentui/input-prompt-model.test.ts

@@ -97,6 +97,43 @@ const GATING_COMMANDS: readonly SlashCommand[] = [
   cmd({ name: 'review' }),
 ];
 
+describe('detectCompletionTarget AT queries', () => {
+  it.each([
+    ['hello @README.md', 'README.md'],
+    ['中文 @文件.ts', '文件.ts'],
+    ['😀 @README.md', 'README.md'],
+    ['@😀file.ts', '😀file.ts'],
+    ['😀😀 @src/𠮷file.ts', 'src/𠮷file.ts'],
+    ['😀 @src/😀file.ts', 'src/😀file.ts'],
+  ])('uses the complete file query from %s', (text, query) => {
+    const cursor = Array.from(text).length;
+    expect(detectCompletionTarget([text], 0, cursor, text, cursor)).toEqual({
+      mode: CompletionMode.AT,
+      query,
+      start: Array.from(text).indexOf('@') + 1,
+      end: cursor,
+    });
+  });
+
+  it('keeps code-point replacement bounds with the cursor inside a Unicode path', () => {
+    const text = '😀 @src/😀file.ts tail';
+    const target = detectCompletionTarget([text], 0, 7, text, 7);
+    expect(target).toEqual({
+      mode: CompletionMode.AT,
+      query: 'src/😀file.ts',
+      start: 3,
+      end: 15,
+    });
+    const applied = applyCompletion(
+      text,
+      target!,
+      { label: '😀done.ts', value: '😀done.ts' },
+      false,
+    );
+    expect(applied.line).toBe('😀 @😀done.ts tail');
+  });
+});
+
 describe('detectCompletionTarget mid-input gating (useCommandCompletion port, R1-86)', () => {
   const detect = (text: string, cursorOffset: number) => {
     const lines = text.split('\n');

packages/cli/src/ui/opentui/input-prompt-model.ts

@@ -216,7 +216,7 @@ export function detectCompletionTarget(
       const pathStart = i + 1;
       return {
         mode: CompletionMode.AT,
-        query: currentLine.substring(pathStart, end),
+        query: codePoints.slice(pathStart, end).join(''),
         start: pathStart,
         end,
       };