Version 2.50 introduced odd JSON behavior

[toddself]

We are having a problem interacting with a server written in GO when we update request from 2.49.0 to 2.50.0. (This issue still exists in the latest 2.x release)

The issue is that the JSON being sent when json: true is set in the options is wrapped as a string.

Here is a request body from v2.49.0:

POST / HTTP/1.1
host: 192.168.1.8:8755
accept: application/json
content-length: 102
Connection: keep-alive

{"directory":"","filename":"6-8-2015.DAT","body":"6-8-2015\t8/6/2015 7:00:00 PM\t8/6/2015 7:21:00 PM"}

Here is the same exact request body from v2.50.0

POST / HTTP/1.1
host: 192.168.1.8:8755
accept: application/json
content-type: application/json
content-length: 118
Connection: keep-alive

"{\"directory\":\"\",\"filename\":\"6-8-2015.DAT\",\"body\":\"6-8-2015\\t8/6/2015 7:00:00 PM\\t8/6/2015 7:21:00 PM\"}"

The latter causes the Go json.Unmarshal method to choke with:
json: cannot unmarshal string into Go value of type main.ServerMessage

Looking through the changelog.md file the only change that seems to be relevant was the addition of an optional "reviver" -- however undoing that change doesn't seem to solve this problem.

[toddself]

ServerMessage is a struct defined as:

type ServerMessage struct {
    Directory string `json:"directory"`
    Filename  string `json:"filename"`
    Body      string `json:"body"`
}

[simov]

@toddself are you sure this doesn't work with the latest version of request? 2.50 had a really nasty bug and you shouldn't use it. If the problem persists using the latest version, can you give me an example code that reproduces the bug (using request options) as you are using them in your app?

[toddself]

It persists in 2.57.0

However, upon further examination this is mostly my fault!

I was calling JSON.stringify on the object and then passing it into the opts object as a string even though I'm setting json: true:

'use strict';

var request = require('request');

module.exports = function(url, directory, filename, file, cb){
  if(typeof cb !== 'function'){
    cb = function(){};
  }

  var payload = JSON.stringify({
    directory: directory,
    filename: filename,
    body: file
  });

  var opts = {
    url: url,
    body: payload,
    json: true,
    method: 'POST',
    followRedirect: false
  };

  console.log('Sending to prompter', opts);

  request(opts, function(err, res, body){
    if(err || res.statusCode === 500){
      err = err || new Error('Prompter returned a 500 '+body);
      console.log('Unable to write to prompter ' + url, err);
      return cb();
    }
    cb(null, res);
  });
};

In 2.49.0 and lower though this worked even with my error. Apparently 2.50.0 fixes this issue.

[simov]

Yep, that might be the case. I think this change is related to #1310 where I fixed a previous change in that logic (not reverted).