index.js

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

// Handle creating/removing shortcuts on Windows when installing/uninstalling.
if (require('electron-squirrel-startup')) {
  app.quit()
}

const createWindow = () => {
  // Create the browser window.
  const mainWindow = new BrowserWindow({
    width: 800,
    height: 600,
    minWidth: 400,
    minHeight: 300,
    titleBarStyle: 'hiddenInset',
    // trafficLightPosition: { x: 20, y: 18 },
    // vibrancy: 'titlebar',
    transparent: true,
  })

  // and load the index.html of the app.
  mainWindow.loadURL('http://localhost:3000')

  // Open the DevTools.
  mainWindow.webContents.openDevTools()
}

// This method will be called when Electron has finished
// initialization and is ready to create browser windows.
// Some APIs can only be used after this event occurs.
app.on('ready', createWindow)

// Quit when all windows are closed, except on macOS. There, it's common
// for applications and their menu bar to stay active until the user quits
// explicitly with Cmd + Q.
app.on('window-all-closed', () => {
  if (process.platform !== 'darwin') {
    app.quit()
  }
})

app.on('activate', () => {
  // On OS X it's common to re-create a window in the app when the
  // dock icon is clicked and there are no other windows open.
  if (BrowserWindow.getAllWindows().length === 0) {
    createWindow()
  }
})

// In this file you can include the rest of your app's specific main process
// code. You can also put them in separate files and import them here.