HTTP2 server push example [Pre-compressed with brotli]

h2.js

// Native
const http2 = require('http2')
const fs = require('fs')
const path = require('path')

// Packages
const cert = require('openssl-self-signed-certificate')
const mime = require('mime')

const {
  HTTP2_HEADER_PATH,
  HTTP_STATUS_NOT_FOUND,
  HTTP_STATUS_INTERNAL_SERVER_ERROR
} = http2.constants

const options = {
  key: cert.key,
  cert: cert.cert,
  passphrase: cert.passphrase
}

const PUBLIC = '/dist'
const COMPRESSED = path.join(__dirname, 'compressed')

const server = http2.createSecureServer(options)

function respondError (err, stream) {
  (err.code === 'ENOENT')
    ? stream.respond({ ':status': HTTP_STATUS_NOT_FOUND })
    : stream.respond({ ':status': HTTP_STATUS_INTERNAL_SERVER_ERROR })
  stream.end()
}

server.on('stream', (stream, headers) => {
  const reqPath = headers[HTTP2_HEADER_PATH]
  const fullPath = path.join(__dirname, reqPath)
  const respondType = mime.getType(fullPath)

  if (reqPath === '/') {
    stream.respondWithFile(`${COMPRESSED}/index.br`, {
      'content-type': 'text/html',
      'content-encoding': 'br'
    }, {
      onError: err => respondError(err, stream)
    })

    stream.pushStream({ ':path': `${PUBLIC}/build.js` }, pushStream => {
      pushStream.respondWithFile(`${COMPRESSED}/build.br`, {
        'content-type': 'application/javascript',
        'content-encoding': 'br'
      }, { onError: err =>
        respondError(err, pushStream)
      })
    })

  } else {
    stream.respondWithFile(`${COMPRESSED}/${path.parse(fullPath).name}.br`, {
      'content-type': respondType,
      'content-encoding': 'br'
    }, {
      onError: err => respondError(err, stream)
    })
  }

})

const PORT = process.env.PORT || 3443

server.listen(PORT)