Restify 5.0 Response.js - Maximum call stack size exceeded - Node 8.1.4

[ianvonholt]

Bug Report

Restify Version

restify@5.0.0

Node.js Version

8.1.4

Expected behaviour

Calling res.getHeaders() would return the appropriate header object.

Actual behaviour

./node_modules/restify/lib/response.js:119
Response.prototype.getHeaders = function getHeaders() {
                                                   ^

RangeError: Maximum call stack size exceeded
    at ServerResponse.getHeaders (./node_modules/restify/lib/response.js:119:52)
    at ServerResponse.get (_http_outgoing.js:130:17)
    at ServerResponse.getHeaders (./node_modules/restify/lib/response.js:120:17)
    at ServerResponse.get (_http_outgoing.js:130:17)
    at ServerResponse.getHeaders (./node_modules/restify/lib/response.js:120:17)
    at ServerResponse.get (_http_outgoing.js:130:17)
    at ServerResponse.getHeaders (./node_modules/restify/lib/response.js:120:17)
    at ServerResponse.get (_http_outgoing.js:130:17)
    at ServerResponse.getHeaders (./node_modules/restify/lib/response.js:120:17)
    at ServerResponse.get (_http_outgoing.js:130:17)

Repro case

const restify = require('restify');
const server = restify.createServer();
server.get('/', function (req, res, next) {
  res.send(200, res.getHeaders());
  next();
});
server.listen(8080, function () {});

Cause

The use of _headers is deprecated and it appears that it is currently a wrapper for getHeaders() Public API in Node 8.1.4.

https://nodejs.org/api/deprecations.html#deprecations_dep0066_outgoingmessage_headers_outgoingmessage_headernames

https://github.com/nodejs/node/blob/v8.1.4/lib/_http_outgoing.js#L128-L144

The problem is the inheritance that Restify 5.0 displays with http.ServerResponse. At https://github.com/restify/node-restify/blob/5.x/lib/response.js#L22 Response is set as the appropriate object.

https://github.com/restify/node-restify/blob/5.x/lib/response.js#L119-L121 Then goes to override the Public API function and causes an infinite loop.

Are you willing and able to fix this?

Simply commenting out https://github.com/restify/node-restify/blob/5.x/lib/response.js#L119-L121 would fix the issue in Node 8 environments as the method already exists.

Node 4.x and Node 6.x do not have a response.getHeaders function and this function seems legitimate in Restify.

A simple replacement would be to check the Response object prior to addition:

if (typeof Response.prototype.getHeaders !== 'function') {
  Response.prototype.getHeaders = function getHeaders() {
      return (this._headers || {});
  };
}