Electron- angular :由于angular组件内部未定义的ipcRenderer而运行Karma错误

import { ipcRenderer } from 'electron';

// 在Electron主进程中
const { ipcMain } = require('electron');

// 监听来自渲染进程的消息
ipcMain.on('message-from-renderer', (event, arg) => {
  // 处理消息并向渲染进程发送回复
  event.sender.send('message-to-renderer', 'Hello from main process!');
});

import { TestBed } from '@angular/core/testing';
import { AppComponent } from './app.component';

describe('AppComponent', () => {
  beforeEach(async () => {
    await TestBed.configureTestingModule({
      declarations: [AppComponent],
    }).compileComponents();
  });

  it('should create the app', () => {
    const fixture = TestBed.createComponent(AppComponent);
    const app = fixture.componentInstance;
    expect(app).toBeTruthy();
  });

  it('should send and receive messages using ipcRenderer', () => {
    const fixture = TestBed.createComponent(AppComponent);
    const app = fixture.componentInstance;

    // 模拟ipcRenderer的on和send方法
    spyOn(window['ipcRenderer'], 'on').and.callFake((channel, callback) => {
      // 模拟接收消息并调用回调函数
      callback('Hello from main process!');
    });
    spyOn(window['ipcRenderer'], 'send').and.callThrough();

    // 调用组件中与ipcRenderer通信的方法
    app.sendMessageToMainProcess();

    // 断言是否正确调用了ipcRenderer的send方法
    expect(window['ipcRenderer'].send).toHaveBeenCalledWith('message-from-renderer', 'Hello from renderer process!');

    // 断言组件中接收到的消息
    expect(app.messageFromMainProcess).toBe('Hello from main process!');
  });
});