electron/default_app/default_app.js

const { app, BrowserWindow, systemPreferences } = require('electron')
const path = require('path')

let mainWindow = null

// Quit when all windows are closed.
app.on('window-all-closed', () => {
  app.quit()
})

exports.load = async (appUrl) => {
  await app.whenReady()

  if (process.platform === 'darwin') {
    systemPreferences.startAppLevelAppearanceTrackingOS()
  }

  const options = {
    width: 900,
    height: 600,
    autoHideMenuBar: true,
    backgroundColor: '#FFFFFF',
    webPreferences: {
      contextIsolation: true,
      nodeIntegration: false,
      preload: path.resolve(__dirname, 'renderer.js'),
      webviewTag: false
    },
    useContentSize: true,
    show: false
  }

  if (process.platform === 'linux') {
    options.icon = path.join(__dirname, 'icon.png')
  }

  mainWindow = new BrowserWindow(options)

  mainWindow.on('ready-to-show', () => mainWindow.show())

  mainWindow.loadURL(appUrl)
  mainWindow.focus()
}