fix(cli): address PR comments for /note command (v3)

packages/cli/src/ui/commands/noteCommand.test.ts

@@ -33,8 +33,10 @@ describe('noteCommand', () => {
     });
   });
 
-  it('should return info message when no args provided and file does not exist', async () => {
-    vi.mocked(fs.readFile).mockRejectedValue(new Error('File not found'));
+  it('should return info message when no args provided and file does not exist (ENOENT)', async () => {
+    const error = new Error('File not found') as NodeJS.ErrnoException;
+    error.code = 'ENOENT';
+    vi.mocked(fs.readFile).mockRejectedValue(error);
 
     const result = await noteCommand.action!(mockContext, '  ');
 
@@ -45,13 +47,30 @@ describe('noteCommand', () => {
     });
   });
 
-  it('should append note to file when args are provided', async () => {
-    const note = 'this is a new note';
+  it('should return error message when readFile fails with other error', async () => {
+    vi.mocked(fs.readFile).mockRejectedValue(new Error('Permission denied'));
+
+    const result = await noteCommand.action!(mockContext, '');
+
+    expect(result).toEqual({
+      type: 'message',
+      messageType: 'error',
+      content: expect.stringContaining(
+        'Failed to read notes: Permission denied',
+      ),
+    });
+  });
+
+  it('should append trimmed note to file when args are provided', async () => {
+    const note = '  this is a new note  ';
     vi.mocked(fs.appendFile).mockResolvedValue(undefined);
 
     const result = await noteCommand.action!(mockContext, note);
 
-    expect(fs.appendFile).toHaveBeenCalledWith(notesPath, `${note}\n`);
+    expect(fs.appendFile).toHaveBeenCalledWith(
+      notesPath,
+      `this is a new note\n`,
+    );
     expect(result).toEqual({
       type: 'message',
       messageType: 'info',

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

@@ -6,6 +6,7 @@
 
 import fs from 'node:fs/promises';
 import path from 'node:path';
+import { isNodeError } from '@google/gemini-cli-core';
 import { CommandKind, type SlashCommand } from './types.js';
 
 export const noteCommand: SlashCommand = {
@@ -24,17 +25,25 @@ export const noteCommand: SlashCommand = {
           messageType: 'info',
           content: `Current notes in ${notesPath}:\n\n${content}`,
         };
-      } catch {
+      } catch (error) {
+        if (isNodeError(error) && error.code === 'ENOENT') {
+          return {
+            type: 'message',
+            messageType: 'info',
+            content: 'No notes found. Use "/note <text>" to add one.',
+          };
+        }
         return {
           type: 'message',
-          messageType: 'info',
-          content: 'No notes found. Use "/note <text>" to add one.',
+          messageType: 'error',
+          content: `Failed to read notes: ${error instanceof Error ? error.message : String(error)}`,
         };
       }
     }
 
     try {
-      await fs.appendFile(notesPath, `${args}\n`);
+      const trimmedNote = args.trim();
+      await fs.appendFile(notesPath, `${trimmedNote}\n`);
       return {
         type: 'message',
         messageType: 'info',