| 936 | } |
| 937 | |
| 938 | function shouldUseNative() { |
| 939 | try { |
| 940 | if (!Object.assign) { |
| 941 | return false; |
| 942 | } |
| 943 | |
| 944 | // Detect buggy property enumeration order in older V8 versions. |
| 945 | |
| 946 | // https://bugs.chromium.org/p/v8/issues/detail?id=4118 |
| 947 | var test1 = new String('abc'); // eslint-disable-line no-new-wrappers |
| 948 | test1[5] = 'de'; |
| 949 | if (Object.getOwnPropertyNames(test1)[0] === '5') { |
| 950 | return false; |
| 951 | } |
| 952 | |
| 953 | // https://bugs.chromium.org/p/v8/issues/detail?id=3056 |
| 954 | var test2 = {}; |
| 955 | for (var i = 0; i < 10; i++) { |
| 956 | test2['_' + String.fromCharCode(i)] = i; |
| 957 | } |
| 958 | var order2 = Object.getOwnPropertyNames(test2).map(function (n) { |
| 959 | return test2[n]; |
| 960 | }); |
| 961 | if (order2.join('') !== '0123456789') { |
| 962 | return false; |
| 963 | } |
| 964 | |
| 965 | // https://bugs.chromium.org/p/v8/issues/detail?id=3056 |
| 966 | var test3 = {}; |
| 967 | 'abcdefghijklmnopqrst'.split('').forEach(function (letter) { |
| 968 | test3[letter] = letter; |
| 969 | }); |
| 970 | if (Object.keys(Object.assign({}, test3)).join('') !== |
| 971 | 'abcdefghijklmnopqrst') { |
| 972 | return false; |
| 973 | } |
| 974 | |
| 975 | return true; |
| 976 | } catch (err) { |
| 977 | // We don't expect any of the above to throw, but better to be safe. |
| 978 | return false; |
| 979 | } |
| 980 | } |
| 981 | |
| 982 | module.exports = shouldUseNative() ? Object.assign : function (target, source) { |
| 983 | var from; |