connect-injector does not work with node 0.11 and express.compress()

[wrr]

Unit tests that access modified response body fail (the body is missing). It can be reproduced with:

nvm use 0.11
npm test

I identified the error to be in this line https://github.com/daffl/connect-injector/blob/master/lib/connect-injector.js#L151.
The line assumes that a call to super(data), will not invoke write(data). This assumption was true in node 0.10 end(data) outputs data directly to an outgoing connection (https://github.com/joyent/node/blob/v0.10/lib/http.js#L959). But with node 0.11 end(data), delegates this job to write(data) (https://github.com/joyent/node/blob/master/lib/_http_outgoing.js#L524).

This causes injector's mixed in write(data) to be invoked again, and the data is buffered and never passed to the original handler.

A fix would be to replace the call to super(data) with original_handler.write(data), followed by super() (with no data passed). I tried an ugly way of saving the original write function:

var real_write = res.write.bind(res);

and this fixed the tests. I'm not sure though that this is fully correct, maybe there is a nicer way that allows somehow to refer to write._super() from end()?

[wrr]

For a reference I'm attaching my fix, but it is not very elegant. I'm not familiar with uberproto, it may allow a much nicer way to fix the problem.

[wrr]

The same problem happens with node 0.10 when compress middleware is used (higher in the stack than the connect-injector, so this is a different issue from #4). The small breaking example is:

var express = require('express');
var app = express();

// XXX
app.use(express.compress());

var injector = require('connect-injector')(
  function when(req, res) {
    return true;
  }, function converter(callback, content, req, res) {
    callback(null, content + ' world');
  });

app.use(injector);

app.get('/', function(req, res) {
  res.send('Hello');
});

var port = process.env.PORT || 5000;
app.listen(port, function() {
  console.log('Listening on ' + port);
});

This returns an empty response if the line marked 'XXX' is enabled.

The problem is that the compress middleware also invokes write() from the end() (please see). The patch included above also solves this problem.

Broken compress middleware support is quite urgent in my case, let me know if I can do anything to help fixing this.