Yang Guo | 4fd355c | 2019-09-19 08:59:03 | [diff] [blame] | 1 | 'use strict'; |
| 2 | |
| 3 | // modified from https://github.com/es-shims/es6-shim |
Nikolay Vitkov | d76576c | 2024-12-02 14:10:15 | [diff] [blame] | 4 | var objectKeys = require('object-keys'); |
Yang Guo | 4fd355c | 2019-09-19 08:59:03 | [diff] [blame] | 5 | var hasSymbols = require('has-symbols/shams')(); |
Tim van der Lippe | 16aca39 | 2020-11-13 11:37:13 | [diff] [blame] | 6 | var callBound = require('call-bind/callBound'); |
Yang Guo | 4fd355c | 2019-09-19 08:59:03 | [diff] [blame] | 7 | var toObject = Object; |
Tim van der Lippe | 16aca39 | 2020-11-13 11:37:13 | [diff] [blame] | 8 | var $push = callBound('Array.prototype.push'); |
| 9 | var $propIsEnumerable = callBound('Object.prototype.propertyIsEnumerable'); |
Yang Guo | 4fd355c | 2019-09-19 08:59:03 | [diff] [blame] | 10 | var originalGetSymbols = hasSymbols ? Object.getOwnPropertySymbols : null; |
| 11 | |
Tim van der Lippe | 16aca39 | 2020-11-13 11:37:13 | [diff] [blame] | 12 | // eslint-disable-next-line no-unused-vars |
Yang Guo | 4fd355c | 2019-09-19 08:59:03 | [diff] [blame] | 13 | module.exports = function assign(target, source1) { |
Nikolay Vitkov | d76576c | 2024-12-02 14:10:15 | [diff] [blame] | 14 | if (target == null) { throw new TypeError('target must be an object'); } |
| 15 | var to = toObject(target); // step 1 |
| 16 | if (arguments.length === 1) { |
| 17 | return to; // step 2 |
| 18 | } |
| 19 | for (var s = 1; s < arguments.length; ++s) { |
| 20 | var from = toObject(arguments[s]); // step 3.a.i |
| 21 | |
| 22 | // step 3.a.ii: |
| 23 | var keys = objectKeys(from); |
Yang Guo | 4fd355c | 2019-09-19 08:59:03 | [diff] [blame] | 24 | var getSymbols = hasSymbols && (Object.getOwnPropertySymbols || originalGetSymbols); |
| 25 | if (getSymbols) { |
Nikolay Vitkov | d76576c | 2024-12-02 14:10:15 | [diff] [blame] | 26 | var syms = getSymbols(from); |
| 27 | for (var j = 0; j < syms.length; ++j) { |
| 28 | var key = syms[j]; |
| 29 | if ($propIsEnumerable(from, key)) { |
| 30 | $push(keys, key); |
Yang Guo | 4fd355c | 2019-09-19 08:59:03 | [diff] [blame] | 31 | } |
| 32 | } |
| 33 | } |
Nikolay Vitkov | d76576c | 2024-12-02 14:10:15 | [diff] [blame] | 34 | |
| 35 | // step 3.a.iii: |
| 36 | for (var i = 0; i < keys.length; ++i) { |
| 37 | var nextKey = keys[i]; |
| 38 | if ($propIsEnumerable(from, nextKey)) { // step 3.a.iii.2 |
| 39 | var propValue = from[nextKey]; // step 3.a.iii.2.a |
| 40 | to[nextKey] = propValue; // step 3.a.iii.2.b |
Yang Guo | 4fd355c | 2019-09-19 08:59:03 | [diff] [blame] | 41 | } |
| 42 | } |
| 43 | } |
Nikolay Vitkov | d76576c | 2024-12-02 14:10:15 | [diff] [blame] | 44 | |
| 45 | return to; // step 4 |
Yang Guo | 4fd355c | 2019-09-19 08:59:03 | [diff] [blame] | 46 | }; |