Adds listCommands endpoint to a2a server (#12604)

Co-authored-by: Juanda <jdgarrido@google.com>
Co-authored-by: Shreya Keshive <shreyakeshive@google.com>

packages/a2a-server/src/commands/extensions.test.ts

@@ -0,0 +1,87 @@
+/**
+ * @license
+ * Copyright 2025 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import { describe, it, expect, vi } from 'vitest';
+import { ExtensionsCommand, ListExtensionsCommand } from './extensions.js';
+import type { Config } from '@google/gemini-cli-core';
+
+const mockListExtensions = vi.hoisted(() => vi.fn());
+vi.mock('@google/gemini-cli-core', async (importOriginal) => {
+  const original =
+    await importOriginal<typeof import('@google/gemini-cli-core')>();
+
+  return {
+    ...original,
+    listExtensions: mockListExtensions,
+  };
+});
+
+describe('ExtensionsCommand', () => {
+  it('should have the correct name', () => {
+    const command = new ExtensionsCommand();
+    expect(command.name).toEqual('extensions');
+  });
+
+  it('should have the correct description', () => {
+    const command = new ExtensionsCommand();
+    expect(command.description).toEqual('Manage extensions.');
+  });
+
+  it('should have "extensions list" as a subcommand', () => {
+    const command = new ExtensionsCommand();
+    expect(command.subCommands.map((c) => c.name)).toContain('extensions list');
+  });
+
+  it('should be a top-level command', () => {
+    const command = new ExtensionsCommand();
+    expect(command.topLevel).toBe(true);
+  });
+
+  it('should default to listing extensions', async () => {
+    const command = new ExtensionsCommand();
+    const mockConfig = {} as Config;
+    const mockExtensions = [{ name: 'ext1' }];
+    mockListExtensions.mockReturnValue(mockExtensions);
+
+    const result = await command.execute(mockConfig, []);
+
+    expect(result).toEqual({ name: 'extensions list', data: mockExtensions });
+    expect(mockListExtensions).toHaveBeenCalledWith(mockConfig);
+  });
+});
+
+describe('ListExtensionsCommand', () => {
+  it('should have the correct name', () => {
+    const command = new ListExtensionsCommand();
+    expect(command.name).toEqual('extensions list');
+  });
+
+  it('should call listExtensions with the provided config', async () => {
+    const command = new ListExtensionsCommand();
+    const mockConfig = {} as Config;
+    const mockExtensions = [{ name: 'ext1' }];
+    mockListExtensions.mockReturnValue(mockExtensions);
+
+    const result = await command.execute(mockConfig, []);
+
+    expect(result).toEqual({ name: 'extensions list', data: mockExtensions });
+    expect(mockListExtensions).toHaveBeenCalledWith(mockConfig);
+  });
+
+  it('should return a message when no extensions are installed', async () => {
+    const command = new ListExtensionsCommand();
+    const mockConfig = {} as Config;
+    mockListExtensions.mockReturnValue([]);
+
+    const result = await command.execute(mockConfig, []);
+
+    expect(result).toEqual({
+      name: 'extensions list',
+      data: 'No extensions installed.',
+    });
+    expect(mockListExtensions).toHaveBeenCalledWith(mockConfig);
+  });
+});