index.js

const electron = require('electron')
const app = electron.app
const BrowserWindow = electron.BrowserWindow

let mainWindow

app.on('ready', createWindow)

app.on('window-all-closed', function () {
    // On OS X it is common for applications and their menu bar
    // to stay active until the user quits explicitly with Cmd + Q
    if (process.platform !== 'darwin') {
        app.quit()
    }
})

app.on('activate', function () {
    // 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 (mainWindow === null) {
        createWindow()
    }
})

function createWindow () {
    mainWindow = new BrowserWindow({width: 970, height: 890})
    mainWindow.setResizable(true)
    mainWindow.loadURL(`file://${__dirname}/index.html`)

    //mainWindow.webContents.openDevTools()

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