www.aleph1.co.uk Git - yaffs-website/blob - node_modules/object-assign/index.js

   1 /*
   2 object-assign
   3 (c) Sindre Sorhus
   4 @license MIT
   5 */
   6
   7 'use strict';
   8 /* eslint-disable no-unused-vars */
   9 var getOwnPropertySymbols = Object.getOwnPropertySymbols;
  10 var hasOwnProperty = Object.prototype.hasOwnProperty;
  11 var propIsEnumerable = Object.prototype.propertyIsEnumerable;
  12
  13 function toObject(val) {
  14         if (val === null || val === undefined) {
  15                 throw new TypeError('Object.assign cannot be called with null or undefined');
  16         }
  17
  18         return Object(val);
  19 }
  20
  21 function shouldUseNative() {
  22         try {
  23                 if (!Object.assign) {
  24                         return false;
  25                 }
  26
  27                 // Detect buggy property enumeration order in older V8 versions.
  28
  29                 // https://bugs.chromium.org/p/v8/issues/detail?id=4118
  30                 var test1 = new String('abc');  // eslint-disable-line no-new-wrappers
  31                 test1[5] = 'de';
  32                 if (Object.getOwnPropertyNames(test1)[0] === '5') {
  33                         return false;
  34                 }
  35
  36                 // https://bugs.chromium.org/p/v8/issues/detail?id=3056
  37                 var test2 = {};
  38                 for (var i = 0; i < 10; i++) {
  39                         test2['_' + String.fromCharCode(i)] = i;
  40                 }
  41                 var order2 = Object.getOwnPropertyNames(test2).map(function (n) {
  42                         return test2[n];
  43                 });
  44                 if (order2.join('') !== '0123456789') {
  45                         return false;
  46                 }
  47
  48                 // https://bugs.chromium.org/p/v8/issues/detail?id=3056
  49                 var test3 = {};
  50                 'abcdefghijklmnopqrst'.split('').forEach(function (letter) {
  51                         test3[letter] = letter;
  52                 });
  53                 if (Object.keys(Object.assign({}, test3)).join('') !==
  54                                 'abcdefghijklmnopqrst') {
  55                         return false;
  56                 }
  57
  58                 return true;
  59         } catch (err) {
  60                 // We don't expect any of the above to throw, but better to be safe.
  61                 return false;
  62         }
  63 }
  64
  65 module.exports = shouldUseNative() ? Object.assign : function (target, source) {
  66         var from;
  67         var to = toObject(target);
  68         var symbols;
  69
  70         for (var s = 1; s < arguments.length; s++) {
  71                 from = Object(arguments[s]);
  72
  73                 for (var key in from) {
  74                         if (hasOwnProperty.call(from, key)) {
  75                                 to[key] = from[key];
  76                         }
  77                 }
  78
  79                 if (getOwnPropertySymbols) {
  80                         symbols = getOwnPropertySymbols(from);
  81                         for (var i = 0; i < symbols.length; i++) {
  82                                 if (propIsEnumerable.call(from, symbols[i])) {
  83                                         to[symbols[i]] = from[symbols[i]];
  84                                 }
  85                         }
  86                 }
  87         }
  88
  89         return to;
  90 };