setup-python/node_modules/jest-util/build/deepCyclicCopy.js
Danny McCormick 39c08a0eaa Initial pass
2019-06-26 21:12:00 -04:00

100 lines
2.4 KiB
JavaScript

'use strict';
Object.defineProperty(exports, '__esModule', {
value: true
});
exports.default = deepCyclicCopy;
/**
* Copyright (c) Facebook, Inc. and its affiliates. All Rights Reserved.
*
* This source code is licensed under the MIT license found in the
* LICENSE file in the root directory of this source tree.
*/
const EMPTY = new Set();
// Node 6 does not have gOPDs, so we define a simple polyfill for it.
if (!Object.getOwnPropertyDescriptors) {
// @ts-ignore: polyfill
Object.getOwnPropertyDescriptors = obj => {
const list = {};
Object.getOwnPropertyNames(obj)
.concat(Object.getOwnPropertySymbols(obj))
.forEach(key => {
// @ts-ignore: assignment with a Symbol is OK.
list[key] = Object.getOwnPropertyDescriptor(obj, key);
});
return list;
};
}
function deepCyclicCopy(
value,
options = {
blacklist: EMPTY,
keepPrototype: false
},
cycles = new WeakMap()
) {
if (typeof value !== 'object' || value === null) {
return value;
} else if (cycles.has(value)) {
return cycles.get(value);
} else if (Array.isArray(value)) {
return deepCyclicCopyArray(value, options, cycles);
} else {
return deepCyclicCopyObject(value, options, cycles);
}
}
function deepCyclicCopyObject(object, options, cycles) {
const newObject = options.keepPrototype
? Object.create(Object.getPrototypeOf(object))
: {};
const descriptors = Object.getOwnPropertyDescriptors(object);
cycles.set(object, newObject);
Object.keys(descriptors).forEach(key => {
if (options.blacklist && options.blacklist.has(key)) {
delete descriptors[key];
return;
}
const descriptor = descriptors[key];
if (typeof descriptor.value !== 'undefined') {
descriptor.value = deepCyclicCopy(
descriptor.value,
{
blacklist: EMPTY,
keepPrototype: options.keepPrototype
},
cycles
);
}
descriptor.configurable = true;
});
return Object.defineProperties(newObject, descriptors);
}
function deepCyclicCopyArray(array, options, cycles) {
const newArray = options.keepPrototype
? new (Object.getPrototypeOf(array)).constructor(array.length)
: [];
const length = array.length;
cycles.set(array, newArray);
for (let i = 0; i < length; i++) {
newArray[i] = deepCyclicCopy(
array[i],
{
blacklist: EMPTY,
keepPrototype: options.keepPrototype
},
cycles
);
}
return newArray;
}