"proxyError" event emitted twice

[subnetmarco]

I created a simple proxy server that tries to proxy the request to a non existent server. I've written this to return an error message when the final host is unreachable.
After I make the request, when the proxyError is caught, I keep getting two times the same error:

{ [Error: connect ECONNREFUSED]
  code: 'ECONNREFUSED',
  errno: 'ECONNREFUSED',
  syscall: 'connect' }
{ [Error: connect ECONNREFUSED]
  code: 'ECONNREFUSED',
  errno: 'ECONNREFUSED',
  syscall: 'connect' }

I'm expecting the error to be thrown only once. This is the code I'm using:

var httpProxy = require('http-proxy');

var server = httpProxy.createServer(function (req, res, proxy) {
  var buffer = httpProxy.buffer(req);

  proxy.proxyRequest(req, res, {
    host: '127.0.0.1',
    port: 10000,
    buffer: buffer
  });

});

server.proxy.on('proxyError', function (err, req, res) {
    // This error is printed two times!
    console.log(err);
});

server.proxy.on('end', function() {
  console.log("The request was proxied.");
});

server.listen(9000);

Assuming that nothing is running on 127.0.0.1:10000, trying to execute:

curl http://127.0.0.1:9000

prints two times the same error message to the console.

I'm running:

• node v0.8.17
• node-http-proxy v0.8.7

[mmalecki]

This is caused by handling an error on both socket and request.

[subnetmarco]

Is this my fault or the lib's fault?

[mmalecki]

Our fault. I'll get to fixing it soon.

[abarre]

+1.

[angn]

+1

[erasmospunk]

The offending code is in http-proxy.py:314-317 (and something similar for proxyWebSocketRequest on lines 732-735).

  //
  // Handle 'error' events from the `reverseProxy`.
  //
  reverseProxy.once('error', proxyError);
  reverseProxy.once('socket', function (socket) {
    socket.once('error', proxyError);
  });

Is it possible that one is fired and the other no?

[erasmospunk]

After some research this part is causing the problem:

reverseProxy.once('socket', function (socket) {
  socket.once('error', proxyError);
});

This is not needed as node.js' ClientRequest object (here the reverseProxy) attaches a listener to the socket 'error'

socket.on('error', socketErrorListener);

The socketErrorListener just re-emits the error from the ClientRequest object.

Look in https://github.com/joyent/node/blob/master/lib/http.js for the socketErrorListener references.

[indexzero]

Fixed in #374