main.js

const electron = require('electron');
const app = electron.app;
const path = require('path');
const url = require('url');

let win;

const isDevelopmentServer = () => {
    return process.env.DEV || false;
};

const getURL = () => {
    if (isDevelopmentServer()) {
        return process.env.ELECTRON_START_URL;
    }

    return url.format({
        pathname: path.join(__dirname, 'dist/index.html'),
        protocol: 'file:',
        slashes: true
    });
};

const createMainWindow = () => {

    const {width, height} = electron.screen.getPrimaryDisplay().workAreaSize;

    win = new electron.BrowserWindow({width, height});

    win.loadURL(getURL());

    if (isDevelopmentServer()) {
        //win.webContents.openDevTools();
    }

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

app.on('ready', createMainWindow);

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

app.on('activate', () => {
    if (win === null) {
        createMainWindow()
    }
});