feat: add folder suggestions to /dir add command (#15724)

packages/cli/src/ui/commands/directoryCommand.test.tsx

@@ -4,10 +4,13 @@
  * SPDX-License-Identifier: Apache-2.0
  */
 
-import { vi, describe, it, expect, beforeEach } from 'vitest';
+import { vi, describe, it, expect, beforeEach, afterEach } from 'vitest';
 import type { Mock } from 'vitest';
 import { directoryCommand } from './directoryCommand.js';
-import { expandHomeDir } from '../utils/directoryUtils.js';
+import {
+  expandHomeDir,
+  getDirectorySuggestions,
+} from '../utils/directoryUtils.js';
 import type { Config, WorkspaceContext } from '@google/gemini-cli-core';
 import type { MultiFolderTrustDialogProps } from '../components/MultiFolderTrustDialog.js';
 import type { CommandContext, OpenCustomDialogActionReturn } from './types.js';
@@ -17,6 +20,15 @@ import * as path from 'node:path';
 import * as trustedFolders from '../../config/trustedFolders.js';
 import type { LoadedTrustedFolders } from '../../config/trustedFolders.js';
 
+vi.mock('../utils/directoryUtils.js', async (importOriginal) => {
+  const actual =
+    await importOriginal<typeof import('../utils/directoryUtils.js')>();
+  return {
+    ...actual,
+    getDirectorySuggestions: vi.fn(),
+  };
+});
+
 describe('directoryCommand', () => {
   let mockContext: CommandContext;
   let mockConfig: Config;
@@ -217,6 +229,47 @@ describe('directoryCommand', () => {
         expect.any(Number),
       );
     });
+
+    describe('completion', () => {
+      const completion = addCommand!.completion!;
+
+      it('should return empty suggestions for an empty path', async () => {
+        const results = await completion(mockContext, '');
+        expect(results).toEqual([]);
+      });
+
+      it('should return empty suggestions for whitespace only path', async () => {
+        const results = await completion(mockContext, '  ');
+        expect(results).toEqual([]);
+      });
+
+      it('should return suggestions for a single path', async () => {
+        vi.mocked(getDirectorySuggestions).mockResolvedValue(['docs/', 'src/']);
+
+        const results = await completion(mockContext, 'd');
+
+        expect(getDirectorySuggestions).toHaveBeenCalledWith('d');
+        expect(results).toEqual(['docs/', 'src/']);
+      });
+
+      it('should return suggestions for multiple paths', async () => {
+        vi.mocked(getDirectorySuggestions).mockResolvedValue(['src/']);
+
+        const results = await completion(mockContext, 'docs/,s');
+
+        expect(getDirectorySuggestions).toHaveBeenCalledWith('s');
+        expect(results).toEqual(['docs/,src/']);
+      });
+
+      it('should handle leading whitespace in suggestions', async () => {
+        vi.mocked(getDirectorySuggestions).mockResolvedValue(['src/']);
+
+        const results = await completion(mockContext, 'docs/, s');
+
+        expect(getDirectorySuggestions).toHaveBeenCalledWith('s');
+        expect(results).toEqual(['docs/, src/']);
+      });
+    });
   });
 
   describe('add with folder trust enabled', () => {

packages/cli/src/ui/commands/directoryCommand.tsx

@@ -14,7 +14,10 @@ import type { SlashCommand, CommandContext } from './types.js';
 import { CommandKind } from './types.js';
 import { MessageType, type HistoryItem } from '../types.js';
 import { refreshServerHierarchicalMemory } from '@google/gemini-cli-core';
-import { expandHomeDir } from '../utils/directoryUtils.js';
+import {
+  expandHomeDir,
+  getDirectorySuggestions,
+} from '../utils/directoryUtils.js';
 import type { Config } from '@google/gemini-cli-core';
 
 async function finishAddingDirectories(
@@ -80,6 +83,27 @@ export const directoryCommand: SlashCommand = {
         'Add directories to the workspace. Use comma to separate multiple paths',
       kind: CommandKind.BUILT_IN,
       autoExecute: false,
+      showCompletionLoading: false,
+      completion: async (context: CommandContext, partialArg: string) => {
+        // Support multiple paths separated by commas
+        const parts = partialArg.split(',');
+        const lastPart = parts[parts.length - 1];
+        const leadingWhitespace = lastPart.match(/^\s*/)?.[0] ?? '';
+        const trimmedLastPart = lastPart.trimStart();
+
+        if (trimmedLastPart === '') {
+          return [];
+        }
+
+        const suggestions = await getDirectorySuggestions(trimmedLastPart);
+
+        if (parts.length > 1) {
+          const prefix = parts.slice(0, -1).join(',') + ',';
+          return suggestions.map((s) => prefix + leadingWhitespace + s);
+        }
+
+        return suggestions.map((s) => leadingWhitespace + s);
+      },
       action: async (context: CommandContext, args: string) => {
         const {
           ui: { addItem },

packages/cli/src/ui/commands/types.ts

@@ -201,5 +201,11 @@ export interface SlashCommand {
     partialArg: string,
   ) => Promise<string[]> | string[];
 
+  /**
+   * Whether to show the loading indicator while fetching completions.
+   * Defaults to true. Set to false for fast completions to avoid flicker.
+   */
+  showCompletionLoading?: boolean;
+
   subCommands?: SlashCommand[];
 }