No parameter support in Content-Type and Accept Header

[awenger]

It's impossible to use parameterized [1] Content-Type and Accept Headers

var restify = require('restify');
var util = require('util');

var server = restify.createServer({
  formatters: {
    'application/vnd.test+json': function(req, res, body) {
      console.log('custom formatter called')
      return JSON.stringify(body);
    }
  }
});
server.pre(restify.pre.userAgentConnection());
server.use(restify.acceptParser(server.acceptable));
server.use(restify.authorizationParser());
server.use(restify.bodyParser({ mapParams: false }));
server.use(restify.queryParser());

server.get('/test/:1', function(req, res, next) {
  res.setHeader('content-type', 'application/vnd.test+json');
  res.send({a:1,b:2});
})

server.listen(5000, function() {});

curl http://localhost:5000/test/1 -H 'Accept: application/vnd.test+json;param=myparam'
Causes the following error:
{"code":"NotAcceptableError","message":"Server accepts: application/vnd.test+json,application/json,text/plain,application/octet-stream,application/javascript"}

Replacing negotiator with the current version (0.4.1) fixes this problem:
custom formatter called
{"a":1,"b":2}

Is there a possibility to set a parameterized Content-Type in the response?

server.get('/test/:1', function(req, res, next) {
  res.setHeader('content-type', 'application/vnd.test+json;param=myparam');
  res.send({a:1,b:2});
})

The Content-Type is truncated to application/vnd.test+json

[1] http://www.w3.org/Protocols/rfc2616/rfc2616-sec3.html#sec3.7

[micahr]

Looks like we are using a more recent version of negotiator now, than when this was filed. @awenger can you confirm that this is still a problem?

[awenger]

This is still impossible with the recent version @micahr . However the source of the problem is different this time.

Negotiator seems to negotiate the content-type by also checking the parameter of the content type (application/vnd.test+json != Accept: application/vnd.test+json;param=myparam) [1].
Therefor I tried to add another formatter:

'application/vnd.test+json;param=myparam': function(req, res, body) {
    console.log('custom formatter called')
    return JSON.stringify(body);
}

However restify strips the param part and passes only application/vnd.test+json to Negotiator [2]. This, as descirbed, is not matched by Negotiator.

This also leads to restify listing application/vnd.test+json twice in the acceptable content-types:

{"code":"NotAcceptableError","message":"Server accepts: application/vnd.test+json,application/vnd.test+json,application/json,text/plain,application/octet-stream,application/javascript"}

[1] https://github.com/jshttp/negotiator/blob/master/lib/mediaType.js#L106
[2]

node-restify/lib/server.js

Lines 87 to 94 in 4e38bd7

	if (k.indexOf(';') !== -1) {
	var tmp = k.split(/\s*;\s*/);
	t = tmp[0];
	if (tmp[1].indexOf('q=') !== -1) {
	q = parseFloat(tmp[1].split('=')[1]);
	}
	}

[micahr]

Thank you for confirming that this is still an issue. I'll get it on our list for the next release.

[awenger]

Thank you for your effort. I'm not 100% sure whether it's a good idea to enforce matching content type parameters during content negotiation. This is what the spec says about it:

The presence or absence of a parameter might be significant to the processing of a media-type, depending on its definition within the media type registry [1]

What do you think @micahr

[1] http://www.w3.org/Protocols/rfc2616/rfc2616-sec3.html#sec3.7

[micahr]

I think we shouldn't be using parameters when matching content-type as they are meant as additional metadata. It would be better to match against the root content-type (application/vnd.test+json in this case) and then allow the consumer to use the parameters to further determine actions needed for a given route.

[awenger]

Sounds good. This is also what I had in mind. But in this case I guess we have to fix it in Negotiator, or did I miss something?

[micahr]

I think we should strip the params before sending the content types for comparison to negotiator.

[rzio]

Hi.
We're having an probably related issue:
When a request is sent with accept header which has a parameter (such as application/json;odata=none), the request hangs for a long time and returns 502.
Should we just strip the paremeters in server.pre handler, and handle it ourselves, or we're missing something, and it should work ?

Restify version 4.0.3 on Node 4.0.0

Update:
We've found why nodejs hangs when accept header has parameters:
restify code sets the response code to 406, but res.end() is never called. Since it was the last handler in the processing chain, and it called a res.send method, we have assumed that something would be sent (a response; an error; ...).
Is this a bug or something we should have implemented by ourselves ?

[retrohacker]

Closing this in favor of #1219

Please correct me if I'm missing a nuance ❤️

[retrohacker]

Hey @rzio, I know this was from back in 2015, but if you are still experiencing this problem please open an issue with a repro case and we will tackle it!