fastify-raw-body bodyLimit reduced test case

README.md

To replicate the issue:

1. Install dependencies with npm install
2. Run the server with node server.js
3. Run the client with node client.js

We expect the request to complete successfully as the body reques is within the limit set on the specific route. You will see that the request does not return an error, it just hangs up.

Replacing BODY_KO with BODY_OK in client.js and re-lunching it will show that normal requests do work.

client.js

const { randomBytes } = require('crypto')
const fetch = require('node-fetch')

const BODY_OK = 1 * 1024
const BODY_KO = 2 * 1024 * 1024

async function run () {
  console.log('before fetch')

  const body = randomBytes(BODY_KO).toString('hex')

  const res = await fetch(
    `http://localhost:3000`, {
      method: 'POST',
      body
    }
  )

  console.log('fetch response', res.ok)
}

run()
  .then(() => console.log('done'))
  .catch(err => console.error(err))

package.json

{
  "name": "replicate-raw-body",
  "version": "1.0.0",
  "dependencies": {
    "fastify": "^4.9.2",
    "fastify-raw-body": "^4.1.0",
    "node-fetch": "^2.6.7"
  }
}

server.js

const Fastify = require('fastify')

async function start () {
  const app = Fastify({
    logger: true
  })
  await app.register(import('fastify-raw-body'), {
    field: 'rawBody',
    global: false,
    runFirst: false,
  })

  app.post('/', {
    config: {
      rawBody: true,
    },
    bodyLimit: 1048576 * 50, // increase limit to 50 mb
    handler (req, reply) {
      reply.send('ok')
    }
  })

  app.listen({ port: 3000 })
}

start().then(() => console.log('started'))