main.js

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

const path = require('path')
const url = require('url')

let mainWindow

let isDev = false

if (
  process.env.NODE_ENV !== undefined &&
  process.env.NODE_ENV === 'development'
) {
  isDev = true
}

function createWindow() {
  mainWindow = new BrowserWindow({
    width: 800,
    height: 600,
    // windows starts hidden, will show later when ready-to-show
    show: false,
    webPreferences: {
      nodeIntegration: true,
    },
  })

  let indexPath

  if (isDev && process.argv.indexOf('--noDevServer') === -1) {
    indexPath = url.format({
      protocol: 'http:',
      host: 'localhost:8080',
      pathname: 'index.html',
      slashes: true,
    })
  } else {
    indexPath = url.format({
      protocol: 'file:',
      pathname: path.join(__dirname, 'dist', 'index.html'),
      slashes: true,
    })
  }

  mainWindow.loadURL(indexPath)

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

    if (isDev) {
      mainWindow.webContents.openDevTools()
    }
  })

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

app.on('ready', createWindow)

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

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