_object-assign.js 1.3 KB

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  1. 'use strict';
  2. // 19.1.2.1 Object.assign(target, source, ...)
  3. var DESCRIPTORS = require('./_descriptors');
  4. var getKeys = require('./_object-keys');
  5. var gOPS = require('./_object-gops');
  6. var pIE = require('./_object-pie');
  7. var toObject = require('./_to-object');
  8. var IObject = require('./_iobject');
  9. var $assign = Object.assign;
  10. // should work with symbols and should have deterministic property order (V8 bug)
  11. module.exports = !$assign || require('./_fails')(function () {
  12. var A = {};
  13. var B = {};
  14. // eslint-disable-next-line no-undef
  15. var S = Symbol();
  16. var K = 'abcdefghijklmnopqrst';
  17. A[S] = 7;
  18. K.split('').forEach(function (k) { B[k] = k; });
  19. return $assign({}, A)[S] != 7 || Object.keys($assign({}, B)).join('') != K;
  20. }) ? function assign(target, source) { // eslint-disable-line no-unused-vars
  21. var T = toObject(target);
  22. var aLen = arguments.length;
  23. var index = 1;
  24. var getSymbols = gOPS.f;
  25. var isEnum = pIE.f;
  26. while (aLen > index) {
  27. var S = IObject(arguments[index++]);
  28. var keys = getSymbols ? getKeys(S).concat(getSymbols(S)) : getKeys(S);
  29. var length = keys.length;
  30. var j = 0;
  31. var key;
  32. while (length > j) {
  33. key = keys[j++];
  34. if (!DESCRIPTORS || isEnum.call(S, key)) T[key] = S[key];
  35. }
  36. } return T;
  37. } : $assign;