generator-cap/generators/cap-deploy/templates/server/server.js

CAP (Connected Apps Platform) is an open-source suite of technologies for rapidly creating web and mobile applications that synchronize data with Salesforce and other systems.

const express = require('express');
const path = require('path');
const app = express();

// Serve static files....
app.use(express.static(__dirname + '/dist/<%=appName%>'));

// Send all requests to index.html
app.get('/*', function(req, res) {
  res.sendFile(path.join(__dirname + '/dist/<%=appName%>/index.html'));
});

// default Heroku PORT
app.listen(process.env.PORT || 3000);