pause() on response of http.request() causes 'aborted' event, and ClientRequest.abort() resumes the response.

[duanyao]

• Version: v7.4.0
• Platform: Windows 10 64bit
• Subsystem: http

Test case:

var request = require('http').request;
var mUrl = require('url');
var url = 'http://example.com'; // or any url

var options = {
  host: mUrl.parse(url).hostname,
  method: 'GET',
  path: url,
};

//console.log('options:', options);

var req = request(options, res => {
  console.log('got response, url=' + url + ', code=' + res.statusCode);
  res.pause();
  res.on('data', (chunk) => {
    console.log('on data:' + chunk.length);
  });
  res.on('end', () => {
    console.log('end');
  });
  res.on('aborted', err => {
    console.log('on aborted');
    setTimeout(()=> console.log('...'), 10000);

    console.log('res.isPaused() before req.abort():' + res.isPaused());
    req.abort();
    console.log('res.isPaused() after req.abort():' + res.isPaused());
  });
});

req.on('error', err => {
  console.error('on error:', err);
});

req.end();

Actual result (stdout):

got response, url=http://example.com, code=200
on aborted
res.isPaused() before req.abort():true
res.isPaused() after req.abort():false
on data:1097
on data:173
end

Note that "on aborted" happens almost immediately after res.pause().

Expected result:

No "aborted" event is fired if the response is not acutally aborted, and ClientRequest.abort() shouldn't resume the response.

I use Wireshark to monitor the traffic, and there is nothing wrong with the response, even if I don't call req.abort().

[bnoordhuis]

You get that 'aborted' event because the server closes the connection while paused on your end, not because you call req.abort(). If that is not what you are seeing locally, please provide the exact steps for me to reproduce.

No "aborted" event is fired if the response is not acutally aborted, and ClientRequest.abort() shouldn't resume the response.

Can you explain why you expect that? Why shouldn't req.abort() unpause the request? It's dead anyway.

[duanyao]

You get that 'aborted' event because the server closes the connection while paused on your end, not because you call req.abort()

No, the server didn't close the connection prematurely. As I said above, Wireshark showed that the complete response was received without problem, regardless the 'aborted' event.

Do you think 'aborted' event should be fired in this case? I don't think so.

• server is sending the response;
• client calls response.pause();
• the response is sent completely, server closes connection;
• 'aborted' event on the response;

If that is not what you are seeing locally, please provide the exact steps for me to reproduce.

Just run the test code above and you'll see the problem always.

Why shouldn't req.abort() unpause the request? It's dead anyway.

Yeah, the request should have died (but seemed not according to Wireshark), but req.abort() brought it to life again ('data' events after 'aborted' event), that's the problem.

[bnoordhuis]

No, the server didn't close the connection prematurely.

I didn't use the word 'prematurely.'

Do you think 'aborted' event should be fired in this case? I don't think so.

No strong opinion. If you want to see it changed, you should present a compelling reason why. Keep in mind there is probably code out there that depends on the current behavior.

[duanyao]

'Abort', by defination, is premature. No? If you don't think so, please explain what is aborted in this case, exactly?

The problem is, l can't tell the difference between premature and normal closing of the connection if pause() is called.

lf this behavior can't be changed, l'd ask to add a new event to act as what 'aborted' should do.

[duanyao]

P.S., l am still not sure about the exact behavior of 'aborted' event. No matter it can be changed or not, it need to be documented in detail.

[Trott]

@nodejs/http

[apapirovski]

This was fixed in 1980a36#diff-e3bc37430eb078ccbafe3aa3b570c91a