feat(core): Add trailing space when completing an at completion suggestion (#5475)

Co-authored-by: gemini-code-assist[bot] <176961590+gemini-code-assist[bot]@users.noreply.github.com>

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

@@ -7,7 +7,7 @@
 /** @vitest-environment jsdom */
 
 import { describe, it, expect, beforeEach, vi, afterEach } from 'vitest';
-import { renderHook, act } from '@testing-library/react';
+import { renderHook, act, waitFor } from '@testing-library/react';
 import { useSlashCompletion } from './useSlashCompletion.js';
 import * as fs from 'fs/promises';
 import * as path from 'path';
@@ -136,7 +136,7 @@ describe('useSlashCompletion', () => {
         expect(result.current.isLoadingSuggestions).toBe(false);
       });
 
-      it('should reset all state to default values', () => {
+      it('should reset all state to default values', async () => {
         const slashCommands = [
           {
             name: 'help',
@@ -165,6 +165,11 @@ describe('useSlashCompletion', () => {
           result.current.resetCompletionState();
         });
 
+        // Wait for async suggestions clearing
+        await waitFor(() => {
+          expect(result.current.suggestions).toEqual([]);
+        });
+
         expect(result.current.suggestions).toEqual([]);
         expect(result.current.activeSuggestionIndex).toBe(-1);
         expect(result.current.visibleStartIndex).toBe(0);
@@ -1288,7 +1293,7 @@ describe('useSlashCompletion', () => {
         result.current.handleAutocomplete(0);
       });
 
-      expect(result.current.textBuffer.text).toBe('@src/file1.txt');
+      expect(result.current.textBuffer.text).toBe('@src/file1.txt ');
     });
 
     it('should complete a file path when cursor is not at the end of the line', () => {
@@ -1347,7 +1352,7 @@ describe('useSlashCompletion', () => {
         result.current.handleAutocomplete(0);
       });
 
-      expect(result.current.textBuffer.text).toBe('@file1.txt @src/file2.txt');
+      expect(result.current.textBuffer.text).toBe('@file1.txt @src/file2.txt ');
     });
   });
 

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

@@ -111,7 +111,7 @@ export function useSlashCompletion(
 
   useEffect(() => {
     if (commandIndex === -1 || reverseSearchActive) {
-      resetCompletionState();
+      setTimeout(resetCompletionState, 0);
       return;
     }
 
@@ -631,17 +631,17 @@ export function useSlashCompletion(
         ) {
           suggestionText = ' ' + suggestionText;
         }
-        suggestionText += ' ';
       }
 
+      suggestionText += ' ';
+
       buffer.replaceRangeByOffset(
         logicalPosToOffset(buffer.lines, cursorRow, completionStart.current),
         logicalPosToOffset(buffer.lines, cursorRow, completionEnd.current),
         suggestionText,
       );
-      resetCompletionState();
     },
-    [cursorRow, resetCompletionState, buffer, suggestions, commandIndex],
+    [cursorRow, buffer, suggestions, commandIndex],
   );
 
   return {