index.js
function discoverKey(arr, discoverableKeys, defaultKey) {
  if (arr.length === 0) return defaultKey;
  if (arr.length === 1) return arr[0];
  for (var i = 0; i < arr.length; i++) {
    if (discoverableKeys[arr[i]]) return arr[i];
  }
  return defaultKey;
}
function discoverKey(arr, discoverableKeys, defaultKey) {
  if (arr.length === 0) return defaultKey;
  if (arr.length === 1) return arr[0];
  for (var i = 0; i < arr.length; i++) {
    if (discoverableKeys[arr[i]]) return arr[i];
  }
  return defaultKey;
}
function discoverKey ( arr , discoverableKeys , defaultKey ) { if ( arr . length === 0 ) return defaultKey ; if ( arr . length === 1 ) return arr [ 0 ] ; for ( var i = 0 ; i < arr . length ; i ++ ) { if ( discoverableKeys [ arr [ i ] ] ) return arr [ i ] ; } return defaultKey ; }
Auto-discover the plural key

@param {Array} keys
@param {Object} discoverableKeys
@param {String} defaultKey
@return {String}
Auto - discover the plural key