mapKeys.js

var baseAssignValue = require('./_baseAssignValue'),
    baseForOwn = require('./_baseForOwn'),
    baseIteratee = require('./_baseIteratee');

/**
 * The opposite of `_.mapValues`; this method creates an object with the
 * same values as `object` and keys generated by running each own enumerable
 * string keyed property of `object` thru `iteratee`. The iteratee is invoked
 * with three arguments: (value, key, object).
 *
 * @static
 * @memberOf _
 * @since 3.8.0
 * @category Object
 * @param {Object} object The object to iterate over.
 * @param {Function} [iteratee=_.identity] The function invoked per iteration.
 * @returns {Object} Returns the new mapped object.
 * @see _.mapValues
 * @example
 *
 * _.mapKeys({ 'a': 1, 'b': 2 }, function(value, key) {
 *   return key + value;
 * });
 * // => { 'a1': 1, 'b2': 2 }
 */
function mapKeys(object, iteratee) {
  var result = {};
  iteratee = baseIteratee(iteratee, 3);

  baseForOwn(object, function(value, key, object) {
    baseAssignValue(result, iteratee(value, key, object), value);
  });
  return result;
}

module.exports = mapKeys;