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- /*
- object-assign
- (c) Sindre Sorhus
- @license MIT
- */
-
- 'use strict';
- /* eslint-disable no-unused-vars */
- var getOwnPropertySymbols = Object.getOwnPropertySymbols;
- var hasOwnProperty = Object.prototype.hasOwnProperty;
- var propIsEnumerable = Object.prototype.propertyIsEnumerable;
-
- function toObject(val) {
- if (val === null || val === undefined) {
- throw new TypeError('Object.assign cannot be called with null or undefined');
- }
-
- return Object(val);
- }
-
- function shouldUseNative() {
- try {
- if (!Object.assign) {
- return false;
- }
-
- // Detect buggy property enumeration order in older V8 versions.
-
- // https://bugs.chromium.org/p/v8/issues/detail?id=4118
- var test1 = new String('abc'); // eslint-disable-line no-new-wrappers
- test1[5] = 'de';
- if (Object.getOwnPropertyNames(test1)[0] === '5') {
- return false;
- }
-
- // https://bugs.chromium.org/p/v8/issues/detail?id=3056
- var test2 = {};
- for (var i = 0; i < 10; i++) {
- test2['_' + String.fromCharCode(i)] = i;
- }
- var order2 = Object.getOwnPropertyNames(test2).map(function (n) {
- return test2[n];
- });
- if (order2.join('') !== '0123456789') {
- return false;
- }
-
- // https://bugs.chromium.org/p/v8/issues/detail?id=3056
- var test3 = {};
- 'abcdefghijklmnopqrst'.split('').forEach(function (letter) {
- test3[letter] = letter;
- });
- if (Object.keys(Object.assign({}, test3)).join('') !==
- 'abcdefghijklmnopqrst') {
- return false;
- }
-
- return true;
- } catch (err) {
- // We don't expect any of the above to throw, but better to be safe.
- return false;
- }
- }
-
- module.exports = shouldUseNative() ? Object.assign : function (target, source) {
- var from;
- var to = toObject(target);
- var symbols;
-
- for (var s = 1; s < arguments.length; s++) {
- from = Object(arguments[s]);
-
- for (var key in from) {
- if (hasOwnProperty.call(from, key)) {
- to[key] = from[key];
- }
- }
-
- if (getOwnPropertySymbols) {
- symbols = getOwnPropertySymbols(from);
- for (var i = 0; i < symbols.length; i++) {
- if (propIsEnumerable.call(from, symbols[i])) {
- to[symbols[i]] = from[symbols[i]];
- }
- }
- }
- }
-
- return to;
- };
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