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