index.js

'use strict'

const fp = require('fastify-plugin')
const Youch = require('youch')

function fastifyErrorPage(fastify, options, next) {
  fastify.setErrorHandler((err, req, reply) => {
    try {
      const youch = new Youch(err, req.raw)
      youch.toHTML().then((html) => {
        reply.type('text/html')
        reply.send(html)
      })
    } catch (error) {
      reply.send(error)
    }
  })

  next()
}

module.exports = fp(fastifyErrorPage, {
  fastify: '^3.x.x',
  name: 'fastify-error-page'
})