timepiece/node_modules/define-properties/index.js

48 lines
1.2 KiB
JavaScript

'use strict';
var keys = require('object-keys');
var hasSymbols = typeof Symbol === 'function' && typeof Symbol('foo') === 'symbol';
var toStr = Object.prototype.toString;
var concat = Array.prototype.concat;
var defineDataProperty = require('define-data-property');
var isFunction = function (fn) {
return typeof fn === 'function' && toStr.call(fn) === '[object Function]';
};
var supportsDescriptors = require('has-property-descriptors')();
var defineProperty = function (object, name, value, predicate) {
if (name in object) {
if (predicate === true) {
if (object[name] === value) {
return;
}
} else if (!isFunction(predicate) || !predicate()) {
return;
}
}
if (supportsDescriptors) {
defineDataProperty(object, name, value, true);
} else {
defineDataProperty(object, name, value);
}
};
var defineProperties = function (object, map) {
var predicates = arguments.length > 2 ? arguments[2] : {};
var props = keys(map);
if (hasSymbols) {
props = concat.call(props, Object.getOwnPropertySymbols(map));
}
for (var i = 0; i < props.length; i += 1) {
defineProperty(object, props[i], map[props[i]], predicates[props[i]]);
}
};
defineProperties.supportsDescriptors = !!supportsDescriptors;
module.exports = defineProperties;