57 lines
1.5 KiB
JavaScript
57 lines
1.5 KiB
JavaScript
'use strict';
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var keys = require('object-keys');
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var foreach = require('foreach');
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var hasSymbols = typeof Symbol === 'function' && typeof Symbol() === 'symbol';
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var toStr = Object.prototype.toString;
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var isFunction = function (fn) {
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return typeof fn === 'function' && toStr.call(fn) === '[object Function]';
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};
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var arePropertyDescriptorsSupported = function () {
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var obj = {};
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try {
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Object.defineProperty(obj, 'x', { enumerable: false, value: obj });
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/* eslint-disable no-unused-vars, no-restricted-syntax */
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for (var _ in obj) { return false; }
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/* eslint-enable no-unused-vars, no-restricted-syntax */
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return obj.x === obj;
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} catch (e) { /* this is IE 8. */
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return false;
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}
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};
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var supportsDescriptors = Object.defineProperty && arePropertyDescriptorsSupported();
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var defineProperty = function (object, name, value, predicate) {
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if (name in object && (!isFunction(predicate) || !predicate())) {
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return;
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}
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if (supportsDescriptors) {
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Object.defineProperty(object, name, {
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configurable: true,
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enumerable: false,
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value: value,
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writable: true
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});
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} else {
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object[name] = value;
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}
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};
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var defineProperties = function (object, map) {
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var predicates = arguments.length > 2 ? arguments[2] : {};
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var props = keys(map);
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if (hasSymbols) {
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props = props.concat(Object.getOwnPropertySymbols(map));
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}
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foreach(props, function (name) {
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defineProperty(object, name, map[name], predicates[name]);
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});
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};
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defineProperties.supportsDescriptors = !!supportsDescriptors;
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module.exports = defineProperties;
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