index.js

/*!
 * assign-symbols <https://github.com/jonschlinkert/assign-symbols>
 *
 * Copyright (c) 2015, Jon Schlinkert.
 * Licensed under the MIT License.
 */

'use strict';

module.exports = function(receiver, objects) {
  if (receiver === null || typeof receiver === 'undefined') {
    throw new TypeError('expected first argument to be an object.');
  }

  if (typeof objects === 'undefined' || typeof Symbol === 'undefined') {
    return receiver;
  }

  if (typeof Object.getOwnPropertySymbols !== 'function') {
    return receiver;
  }

  var isEnumerable = Object.prototype.propertyIsEnumerable;
  var target = Object(receiver);
  var len = arguments.length, i = 0;

  while (++i < len) {
    var provider = Object(arguments[i]);
    var names = Object.getOwnPropertySymbols(provider);

    for (var j = 0; j < names.length; j++) {
      var key = names[j];

      if (isEnumerable.call(provider, key)) {
        target[key] = provider[key];
      }
    }
  }
  return target;
};