server.js

const fs = require('fs');
const key = fs.readFileSync('./key.pem');
const cert = fs.readFileSync('./cert.pem');
const https = require('https');

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

const port = parseInt(process.env.PORT, 10) || 3000;
const dev = process.env.NODE_ENV !== 'production';
const app = next({ dev });
const handle = app.getRequestHandler();

app.prepare().then(() => {
  const server = express();
  const httpsServer = https.createServer({ key: key, cert: cert }, server);

  server.get('/a', (req, res) => {
    return app.render(req, res, '/a', req.query);
  });

  server.get('/b', (req, res) => {
    return app.render(req, res, '/b', req.query);
  });

  server.get('/posts/:id', (req, res) => {
    return app.render(req, res, '/posts', { id: req.params.id });
  });

  server.all('*', (req, res) => {
    return handle(req, res);
  });

  httpsServer.listen(port, (err) => {
    if (err) throw err;
    console.log(`> Ready on http://localhost:${port}`);
  });
});