Read all comments below. This is the cleaner version for your Node.js App

main.js

const { app, BrowserWindow } = require("electron");

app.on("ready", () => {
  let mainWindow = new BrowserWindow({
    width: 800,
    height: 600,
    webPreferences: {
      nodeIntegration: true
    }
  });

  mainWindow.loadFile("index.html");

  // Hide the developer tools.
  mainWindow.webContents.closeDevTools();

  // Set the menu to null to hide the default menu.
  mainWindow.setMenu(null);
});

app.on("window-all-closed", () => {
  app.quit();
});

app.on("browser-window-created", (event, win) => {
  // Hide the menu on all windows including popups.
  win.setMenu(null);
});