// collapsed onto one line
const getParams(href) => (href.split('?')[1] || '').split('&').map(kvp => kvp.split('=')).reduce((acc, kvp) => { acc[kvp[0]] = kvp[1]; return acc }, {})

// spread out into a traditional function
function getParams(href) {
  return (href.split('?')[1] || '')
    .split('&')
    .map(kvp => kvp.split('='))
    .reduce((acc, kvp) => {
      acc[kvp[0]] = kvp[1];
      return acc
    }, {})
}