main.js

// Modules to control application life and create native browser window
const { app, BrowserWindow } = require('electron');
const path = require('path');
const usb = require('usb');

let windows = [];

const webusb = new usb.WebUSB({
    allowAllDevices: true
});

const showDevices = async () => {
    const devices = await webusb.getDevices();
    const text = devices.map(d => `${d.vendorId}\t${d.productId}\t${d.serialNumber || '<no serial>'}`);
    text.unshift('VID\tPID\tSerial\n-------------------------------------');

    windows.forEach(win => {
        if (win) {
            win.webContents.send('devices', text.join('\n'));
        }
    });
};

const createWindow = () => {
    // Create the browser window.
    const win = new BrowserWindow({
        width: 800,
        height: 600,
        webPreferences: {
            preload: path.join(__dirname, 'preload.js')
        }
    });

    // and load the index.html of the app.
    win.loadFile('index.html');

    // Open the DevTools.
    // win.webContents.openDevTools()

    windows.push(win);
    showDevices();
};

// 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.whenReady().then(() => {
    webusb.addEventListener('connect', showDevices);
    webusb.addEventListener('disconnect', showDevices);

    createWindow();

    app.on('activate', () => {
        // On macOS 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();
    });
});

// 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', () => {
    webusb.removeEventListener('connect', showDevices);
    webusb.removeEventListener('disconnect', showDevices);

    app.quit();
});

// 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 require them here.