53 lines
2.0 KiB
JavaScript
53 lines
2.0 KiB
JavaScript
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'use strict';
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var DESCRIPTORS = require('../internals/descriptors');
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var fails = require('../internals/fails');
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var objectKeys = require('../internals/object-keys');
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var getOwnPropertySymbolsModule = require('../internals/object-get-own-property-symbols');
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var propertyIsEnumerableModule = require('../internals/object-property-is-enumerable');
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var toObject = require('../internals/to-object');
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var IndexedObject = require('../internals/indexed-object');
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var nativeAssign = Object.assign;
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var defineProperty = Object.defineProperty;
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// `Object.assign` method
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// https://tc39.github.io/ecma262/#sec-object.assign
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module.exports = !nativeAssign || fails(function () {
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// should have correct order of operations (Edge bug)
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if (DESCRIPTORS && nativeAssign({ b: 1 }, nativeAssign(defineProperty({}, 'a', {
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enumerable: true,
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get: function () {
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defineProperty(this, 'b', {
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value: 3,
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enumerable: false
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});
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}
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}), { b: 2 })).b !== 1) return true;
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// should work with symbols and should have deterministic property order (V8 bug)
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var A = {};
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var B = {};
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// eslint-disable-next-line no-undef
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var symbol = Symbol();
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var alphabet = 'abcdefghijklmnopqrst';
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A[symbol] = 7;
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alphabet.split('').forEach(function (chr) { B[chr] = chr; });
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return nativeAssign({}, A)[symbol] != 7 || objectKeys(nativeAssign({}, B)).join('') != alphabet;
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}) ? function assign(target, source) { // eslint-disable-line no-unused-vars
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var T = toObject(target);
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var argumentsLength = arguments.length;
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var index = 1;
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var getOwnPropertySymbols = getOwnPropertySymbolsModule.f;
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var propertyIsEnumerable = propertyIsEnumerableModule.f;
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while (argumentsLength > index) {
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var S = IndexedObject(arguments[index++]);
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var keys = getOwnPropertySymbols ? objectKeys(S).concat(getOwnPropertySymbols(S)) : objectKeys(S);
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var length = keys.length;
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var j = 0;
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var key;
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while (length > j) {
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key = keys[j++];
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if (!DESCRIPTORS || propertyIsEnumerable.call(S, key)) T[key] = S[key];
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}
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} return T;
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} : nativeAssign;
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