Serving non-standard HTTP method with ExpressJS

Question

I would like to write an HTTP server that answer to request using a non-standard HTTP method (verb). For instance, the client would make a request like FOO / HTTP/.1.1

Answer 1

As others have said, Node.js' HTTP server library is configured to accept only specific verbs. Ben Noordius' suggestion of using Parsley doesn't work either, since that library accepts an even smaller whitelist of verbs. (It also hasn't been maintained in quite some time.)

At this stage, if we want to support oddball requests, we have to take more drastic measures. Here's a nice ugly hack for you that involves duck punching some internal behavior. This works on v0.10.x of Node.js, but test carefully on newer versions as they become available.

In my case, I needed to support not only a non-standard verb, but a non-standard protocol version identifier as well, and a missing Content-Length header for Icecast source streams:

SOURCE /live ICE/1.0

The following should get you started:

server.on('connection', function (socket) {
    var originalOnDataFunction = socket.ondata;
    var newLineOffset;
    var receiveBuffer = new Buffer(0);
    socket.ondata = function (d, start, end) {
        receiveBuffer = Buffer.concat([receiveBuffer, d.slice(start, end)]);
        if ((newLineOffset = receiveBuffer.toString('ascii').indexOf('\n')) > -1) {
            var firstLineParts = receiveBuffer.slice(0, newLineOffset).toString().split(' ');
            firstLineParts[0] = firstLineParts[0].replace(/^SOURCE$/ig, 'PUT');
            firstLineParts[2] = firstLineParts[2].replace(/^ICE\//ig, 'HTTP/');
            receiveBuffer = Buffer.concat([
                new Buffer(
                    firstLineParts.join(' ') + '\r\n' + 
                    'Content-Length: 9007199254740992\r\n'
                ), 
                receiveBuffer.slice(newLineOffset +1)
            ]);

            socket.ondata = originalOnDataFunction;
            socket.ondata.apply(this, [receiveBuffer, 0, receiveBuffer.length]);
        }
    };
}

It's ugly, but works. I'm not particularly happy about it, but when choosing between a rough built-from-the-ground-up HTTP parser or tweaking an existing one, I choose to tweak in this instance.