ERR_STREAM_WRITE_AFTER_END when piping request body

[alxndrsn]

Describe the bug

Node.js version: v22.14.0

supertest version: 7.1.0

Description: in some circumstances, calling stream.pipe(supertestRequest) can throw ERR_STREAM_WRITE_AFTER_END

Actual behavior

stream.pipe(supertestRequest) throws ERR_STREAM_WRITE_AFTER_END

Expected behavior

Should pipe the stream to the request.

Code to reproduce

The following requests with different stream types have different results with https://httpbin.org/post.

Changing the server name (e.g. https://httpbingo.org) can cause both types of streams to fail with ERR_STREAM_WRITE_AFTER_END, so server behaviour may be a factor.

working:

> req = require('supertest')('https://httpbin.org').post('/post'); stream.Readable.from('hi').pipe(req, { end: false }); try { await req; console.log({ status:rez.status, headers:rez.headers, body:rez.body }) } catch(err) { console.log('Caught:', err) }
{
  status: 200,
...

broken:

> req = require('supertest')('https://httpbin.org').post('/post'); rs = fs.createReadStream('./package.json'); rs.pipe(req, { end: false }); try { await req; console.log({ status:rez.status, headers:rez.headers, body:rez.body }) } catch(err) { console.log('Caught:', err) }
Uncaught Error [ERR_STREAM_WRITE_AFTER_END]: write after end

Reference:

> await fetch('https://httpbin.org/post', { method:'POST', body:stream.Readable.from('hi'), duplex:'half' })
Response {
  status: 200,
...

> await fetch('https://httpbin.org/post', { method:'POST', body:fs.createReadStream('./package.json'), duplex:'half' })
Response {
  status: 200,
...

Checklist

• I have searched through GitHub issues for similar issues.
• I have completely read through the README and documentation.
• I have tested my code with the latest version of Node.js and this package and confirmed it is still not working.

[titanism]

🎉 This should now be resolved, please upgrade to the latest versions of supertest and superagent:

• supertest v7.1.2 released to npm https://github.com/forwardemail/supertest/releases/tag/v7.1.2
• superagent v10.2.2 released to npm https://github.com/forwardemail/superagent/releases/tag/v10.2.2

🔋 Maintenance supported by Forward Email (@forwardemail) at https://forwardemail.net

Can you confirm if this fixes the issue?

[alxndrsn]

@titanism Is there a link to the PR/commit that fixes the issue? I can't find any reference to it in the linked superagent/supertest release notes.

[titanism]

I (think) this might be fixed from the upstream changes made to formidable implementation with a PassThrough stream.

forwardemail/superagent@c40db6d

Not 100%. This was a very quick implementation to get all tests working and most issues fixed I believe

[halfninja]

Still occurs on supertest@7.1.4 / superagent@10.2.3, Node.js v22.14.0

As well as the write after end error, this is printed to the console after a couple of seconds

superagent: double callback bug

I don't think formidable would be involved as this isn't a multipart request.

[halfninja]

I think this is a couple of things that are wrong with how we're making request here. Firstly use of .end (which .pipe uses) is not allowed to mix with .then (which includes await) - you need to use .end if you are using pipes.

https://forwardemail.github.io/superagent/#promise-and-generator-support

If you're using promises, do not call .end() or .pipe(). Any use of .then() or await disables all other ways of using the request.

You also need to wait for your data stream to finish first before adding the .end handler. This works for me (I've added some newlines but wrapped it in an IIFE so it can be pasted into the REPL):

(function() {
  req = require('supertest')('https://httpbin.org').post('/post'); 
  rs = fs.createReadStream('./package.json'); 
  rs.pipe(req, { end: false });
  rs.on('end', () => {
    req.end((err, rez) => {
      if (err) console.log('Caught:', err);
      else console.log({ status: rez.status, headers: rez.headers, body: rez.body });
    });
  });
})();