downcase_json_keys.js

function downcaseJSONKeys(obj) {
  if (!obj) {
    return;
  }
  if (typeof obj !== 'Object' && typeof obj !== 'object') {
    return;
  }
  var keys = Object.keys(obj);
  var result = {};
  keys.map(function(k, v) {
    if (typeof k === 'string') {
      if (typeof obj[k] === 'string') {
        result[k.toLowerCase()] = obj[k].toLowerCase();
      } else {
        // if the node is an object, perform the same process over that node
        if (typeof obj[k] === 'Object' || typeof obj[k] === 'object') {
          result[k.toLowerCase()] = downcaseJSONKeys(obj[k]);
        } else {
          result[k.toLowerCase()] = obj[k];
        }
      }
    }
  });
  return result;
}