Détection du type de connexion

getNetworkType.js

/**
 * Detect the type of network
 * @link http://caniuse.com/#feat=resource-timing
 */
function getNetwork() {

  // Default case if the network detection api is not available
  if (!window.performance || !window.performance.getEntriesByName) {
    return '4G';
  }

  const js = performance.getEntriesByName(location.origin + '/js/vendor.min.js')[0] || {duration: 290};
  const DELTA = js.duration * 1.2;

  // For a file 80ko Gzipped
  const map = {
    dsl   : 40,
    '4G'  : 290,
    '3G+' : 740,
    '3G'  : 1550,
    '2G'  : 4550
  };

  return Object
    .keys(map)
    .reduce((prev, curr) => {
      return (Math.abs(map[curr] - DELTA) < Math.abs(map[prev] - DELTA) ? curr : prev);
    }, 'dsl');
}