[Extension Reloading]: Update custom commands, add enable/disable command (#12547)

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

@@ -8,7 +8,11 @@ import { useCallback, useMemo, useEffect, useState } from 'react';
 import { type PartListUnion } from '@google/genai';
 import process from 'node:process';
 import type { UseHistoryManagerReturn } from './useHistoryManager.js';
-import type { Config } from '@google/gemini-cli-core';
+import type {
+  Config,
+  ExtensionsStartingEvent,
+  ExtensionsStoppingEvent,
+} from '@google/gemini-cli-core';
 import {
   GitService,
   Logger,
@@ -39,6 +43,7 @@ import {
   type ExtensionUpdateAction,
   type ExtensionUpdateStatus,
 } from '../state/extensions.js';
+import { appEvents } from '../../utils/events.js';
 
 interface SlashCommandProcessorActions {
   openAuthDialog: () => void;
@@ -249,11 +254,27 @@ export const useSlashCommandProcessor = (
       ideClient.addStatusChangeListener(listener);
     })();
 
+    // TODO: Ideally this would happen more directly inside the ExtensionLoader,
+    // but the CommandService today is not conducive to that since it isn't a
+    // long lived service but instead gets fully re-created based on reload
+    // events within this hook.
+    const extensionEventListener = (
+      _event: ExtensionsStartingEvent | ExtensionsStoppingEvent,
+    ) => {
+      // We only care once at least one extension has completed
+      // starting/stopping
+      reloadCommands();
+    };
+    appEvents.on('extensionsStarting', extensionEventListener);
+    appEvents.on('extensionsStopping', extensionEventListener);
+
     return () => {
       (async () => {
         const ideClient = await IdeClient.getInstance();
         ideClient.removeStatusChangeListener(listener);
       })();
+      appEvents.off('extensionsStarting', extensionEventListener);
+      appEvents.off('extensionsStopping', extensionEventListener);
     };
   }, [config, reloadCommands]);