qs.js

const reg = new RegExp("([^?=&]+)(=([^&]*))?", "g")

function qs (uri) {
  const obj = {}
  uri = uri.replace(/^.*\?/, '')
  uri.replace(reg, map)
  return obj

  function map (a0, a1, a2, a3) {
    obj[decodeURIComponent(a1)] = decodeURIComponent(a3)
  }
}

console.log(qs('http:///foo/bar/#hello?world=bar'))
console.log(qs('/foo/bar/#hello?world=bar&foo=hey'))
console.log(qs('/foo/bar/#hello?world=bar&foo=hey&bbbbuuuub_foo=oi'))