defaultHandler memory leak

[3y3]

defaultHandler will cause memory leak if user doesn't listens on response event.

Possible fix:

var EventEmitter = require('events').EventEmitter;
function defaultHandler(request, options, cb) {
    var url = (typeof options === 'string' ? urlParse(options) : options).href;
    var start = new Date();

    setImmediate(console.log, chalk.gray('      → ' + url));

    var wasHandled = typeof cb === 'function';

    return request(options, cb)
        .once('response', function (response) {
            var request = response.req;
            if (!wasHandled && EventEmitter.listenerCount(request, 'response') === 0)
                response.resume();

            var status = response.statusCode;
            var s = status / 100 | 0;
            console.log('  ' + chalk[colorCodes[s]](status) + ' ← ' + url + ' ' + chalk.gray(time(start)));
        })
        .on('error', function (err) {
            console.log('  ' + chalk.red('xxx') + ' ← ' + url + ' ' + chalk.red(err.message));
        });
}

[floatdrop]

@3y3 this will affect how user code is working. If user do not listens on response data events neither should we.

[3y3]

Mmm...

const debugHttp = require('debug-http');
debugHttp(); // Ok, we wrap http.request and now we listen on `response` event at any time, but...

const http = require('http');

// ...user doesn't handles response. By default in this case node dumps all data.
// This logic became broken if we start to listen on `response` event in wrapper.
http.get('http://google.com'); 

https://github.com/nodejs/node/blob/master/lib/_http_client.js#L421-L427
So in wrapped mode we receive a lot of paused connections, and change expected behavior.

[floatdrop]

@3y3 okay, now I get it. Is var wasHandled = typeof cb === 'function'; necessary? You have check for listenerCount (it will be non-zero, if there was callback).

[3y3]

var wasHandled = typeof cb === 'function'; is necessary
We check listenerCount when cb is already called and removed from listeners list.

[3y3]

You can check the difference for var wasHandled = typeof cb === 'function';
on next example:

const debugHttp = require('debug-http');
debugHttp();

const http = require('http');

http.get('http://google.com', function cb(response) {
  response.on('readable', function() {
    // will be missed without `wasHandled`
    console.log('readable:', response.read());
  });
  response.on('end', function() {
    console.log('end');
  });
}); 

[floatdrop]

@3y3 thanks for pointing it out!