Use NextJS custom server for apex domain to www redirects

server.ts

const { createServer } = require('http');
const { parse } = require('url');
const next = require('next');

const dev = process.env.NODE_ENV !== 'production';
const app = next({ dev });
const handle = app.getRequestHandler();
const port = process.env.APP_PORT || 8080;

app.prepare().then(() => {
    createServer((req, res) => {
        const parsedUrl = parse(req.url, true);
        if (req.headers.host?.indexOf('example.com') === 0) {
            res.writeHead(301, {
                Location: 'https://www.example.com' + req.url,
            });
            res.end();
        } else {
            handle(req, res, parsedUrl);
        }
    }).listen(port, err => {
        if (err) throw err;
    });
});