micro-readability-further-breakup.js

function extractParamStrings(s) {
  if (s[0] === '?') s = s.slice(1, s.length)
  return s.split('&')
}

const extractParamKeyValPair = paramString => 
  paramString.split('=').map(decodeURIComponent)

const addParam = (toObj, [key, val]) => {
  toObj[key] = val
  return toObj
}
  
export function fromUrlQuery(str) {
  if (!str) return {}
  
  return extractParamStrings(str)
    .map(extractParamKeyValPair)
    .reduce(addParam, {})
}