main.js

require('electron-reload');

const { app, BrowserWindow } = require('electron');
const path = require('path');
const isDev = require('electron-is-dev');

let mainWindow;

function createWindow() {
  mainWindow = new BrowserWindow({
    show: false,
    width: 800,
    height: 600,
    maxWidth: 800,
    maxHeight: 600,
    resizable: false,
    title: 'Shutdown Windows',
    autoHideMenuBar: true,
    center: true,
    webPreferences: {
      nodeIntegration: true
    }
  });

  mainWindow.loadURL(
    isDev
      ? 'http://localhost:3000'
      : `file://${path.join(__dirname, 'build/index.html')}`
  );

  mainWindow.on('closed', () => {
    mainWindow = null;
  });

  mainWindow.once('ready-to-show', () => mainWindow.show());
}

app.on('ready', createWindow);

app.on('window-all-closed', () => {
  if (process.platform !== 'darwin') app.quit();
});

app.on('activate', () => {
  if (mainWindow === null) createWindow();
});