[DEPRECATED] use this instead https://github.com/sindresorhus/query-string

buildQuery.js

/*
 * convert ojbect into query params format
 * used for request with content-type application/x-www-form-urlencoded
 *
 * e.g 
 * { param: "someVal", param2: "otherVal" } 
 *
 * is converted into
 *
 * param1=someVal&param2=otherVal
 */
function buildQuery (params) {
  const notNull = x => x !== null

  const esc = encodeURIComponent
  const queryString = Object.keys(params).map((k) =>
    params[k] !== null || params[k] !== undefined ? esc(k) + '=' + esc(params[k]) : null
  ).filter(notNull)

  return queryString.length >= 1
    ? queryString.join('&')
    : ''
}