HTTPS redirect express.js node kind of specifically for Heroku

app.js

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

app.use((req, res, next) => {
  if (req.headers['x-forwarded-proto'] !== 'https' && process.env.NODE_ENV === 'production') {
    res.redirect(`https://${req.hostname}${req.url}`);
  } else {
    next();
  }
});