text: const express = require('express');
  const helmet = require('helmet');
  const app = express();
  
  let ninetyDaysInSeconds = 90*24*60*60;
  
  app.use(helmet.hidePoweredBy());
  app.use(helmet.frameguard({ action: "deny" }));
  app.use(helmet.xssFilter());
  app.use(helmet.noSniff());
  app.use(helmet.ieNoOpen());
  app.use(helmet.hsts({
    maxAge: ninetyDaysInSeconds,
    force: true
  }));
  app.use(helmet.dnsPrefetchControl());
  app.use(helmet.noCache());
  app.use(helmet.contentSecurityPolicy({
    directives: {
      defaultSrc: ["'self'"],
      scriptSrc: ["'self'", 'trusted-cdn.com']
    }
  }));
  module.exports = app;
  const api = require('./server.js');
  app.use(express.static('public'));
  app.disable('strict-transport-security');
  app.use('/_api', api);
  app.get("/", function (request, response) {
    response.sendFile(__dirname + '/views/index.html');
  });
  let port = process.env.PORT || 3000;
  app.listen(port, () => {
    console.log(`Your app is listening on port ${port}`);
  });
  