main.js

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

let win

function createWindow () {
  win = new BrowserWindow({width: 800, height: 600})
  win.loadURL(
    url.format({
    pathname: path.join(__dirname, 'index.html'),
    protocol: 'file:',
    slashes: true
    })
  )
  win.on('closed', () => {
    win = null
  })
}
app.on('ready', createWindow)
app.on('window-all-closed', () => {
  if (process.platform !== 'darwin') {
    app.quit()
  }
})