Fix messages failing to serialize and send with MongoDB ObjectId (BSON object)

Fix messages failing to serialize and send with MongoDB ObjectId (BSON object)

Closes https://gitlab.com/gitlab-org/gitter/webapp/issues/1898

Finding differences in Faye.copyObject implementation

Setup:

# Run in the `gitter/faye` repo directory
$ npm link
# Run in the webapp repo directory
$ npm link gitter-faye
$ npm start -- --inspect-node

javascript/faye.js

var _ = require('lodash');
var dumpKeysRecursively = require('recursive-keys').dumpKeysRecursively;

var Faye = {
  // ...

  copyObject: function(object) {
    var newResult = JSON.parse(JSON.stringify(object));
    var oldResult = Faye.copyObjectLegacy(object);

    var newKeys = dumpKeysRecursively(newResult).sort();
    var oldKeys = dumpKeysRecursively(oldResult).sort();

    if (!_.isEqual(oldKeys, newKeys)) {
      //console.warn('Faye.copyObject different result (old, new)\n', oldResult, '\n', newResult);
      let difference = oldKeys
        .filter(x => {
          var oldValue = _.get(oldResult, x);
          return (oldValue !== undefined && typeof oldValue !== 'function') && !newKeys.includes(x);
        })
        .concat(newKeys.filter(x => {
          var oldValue = _.get(oldResult, x);
          return (oldValue !== undefined && typeof oldValue !== 'function') && !oldKeys.includes(x);
        }));

      if(difference && difference.length > 0) {
        debugger;
      }
    }

    return newResult;
  },

  copyObjectLegacy: function(object) {
    var clone, i, key;
    if (object instanceof Array) {
      clone = [];
      i = object.length;
      while (i--) clone[i] = Faye.copyObjectLegacy(object[i]);
      return clone;
    } else if (typeof object === 'object') {
      clone = (object === null) ? null : {};
      for (key in object) clone[key] = Faye.copyObjectLegacy(object[key]);
      return clone;
    } else {
      return object;
    }
  },
};