App JS for fastify

app.js

import stat from 'fastify-static';
import { join, dirname } from 'path';
import { fileURLToPath } from 'url';
import { readFileSync } from 'fs';

// ...

  app.register(stat, {
    root: join(dirname(fileURLToPath(import.meta.url)), './public'),
    preCompressed: true
  });

  app.setNotFoundHandler((_req, res) => res.sendFile('index.html'));