deep-extend.js (4293B)
1/*! 2 * @description Recursive object extending 3 * @author Viacheslav Lotsmanov <lotsmanov89@gmail.com> 4 * @license MIT 5 * 6 * The MIT License (MIT) 7 * 8 * Copyright (c) 2013-2018 Viacheslav Lotsmanov 9 * 10 * Permission is hereby granted, free of charge, to any person obtaining a copy of 11 * this software and associated documentation files (the "Software"), to deal in 12 * the Software without restriction, including without limitation the rights to 13 * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of 14 * the Software, and to permit persons to whom the Software is furnished to do so, 15 * subject to the following conditions: 16 * 17 * The above copyright notice and this permission notice shall be included in all 18 * copies or substantial portions of the Software. 19 * 20 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 21 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS 22 * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR 23 * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER 24 * IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN 25 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. 26 */ 27 28'use strict'; 29 30function isSpecificValue(val) { 31 return ( 32 val instanceof Buffer 33 || val instanceof Date 34 || val instanceof RegExp 35 ) ? true : false; 36} 37 38function cloneSpecificValue(val) { 39 if (val instanceof Buffer) { 40 var x = Buffer.alloc 41 ? Buffer.alloc(val.length) 42 : new Buffer(val.length); 43 val.copy(x); 44 return x; 45 } else if (val instanceof Date) { 46 return new Date(val.getTime()); 47 } else if (val instanceof RegExp) { 48 return new RegExp(val); 49 } else { 50 throw new Error('Unexpected situation'); 51 } 52} 53 54/** 55 * Recursive cloning array. 56 */ 57function deepCloneArray(arr) { 58 var clone = []; 59 arr.forEach(function (item, index) { 60 if (typeof item === 'object' && item !== null) { 61 if (Array.isArray(item)) { 62 clone[index] = deepCloneArray(item); 63 } else if (isSpecificValue(item)) { 64 clone[index] = cloneSpecificValue(item); 65 } else { 66 clone[index] = deepExtend({}, item); 67 } 68 } else { 69 clone[index] = item; 70 } 71 }); 72 return clone; 73} 74 75function safeGetProperty(object, property) { 76 return property === '__proto__' ? undefined : object[property]; 77} 78 79/** 80 * Extening object that entered in first argument. 81 * 82 * Returns extended object or false if have no target object or incorrect type. 83 * 84 * If you wish to clone source object (without modify it), just use empty new 85 * object as first argument, like this: 86 * deepExtend({}, yourObj_1, [yourObj_N]); 87 */ 88var deepExtend = module.exports = function (/*obj_1, [obj_2], [obj_N]*/) { 89 if (arguments.length < 1 || typeof arguments[0] !== 'object') { 90 return false; 91 } 92 93 if (arguments.length < 2) { 94 return arguments[0]; 95 } 96 97 var target = arguments[0]; 98 99 // convert arguments to array and cut off target object 100 var args = Array.prototype.slice.call(arguments, 1); 101 102 var val, src, clone; 103 104 args.forEach(function (obj) { 105 // skip argument if isn't an object, is null, or is an array 106 if (typeof obj !== 'object' || obj === null || Array.isArray(obj)) { 107 return; 108 } 109 110 Object.keys(obj).forEach(function (key) { 111 src = safeGetProperty(target, key); // source value 112 val = safeGetProperty(obj, key); // new value 113 114 // recursion prevention 115 if (val === target) { 116 return; 117 118 /** 119 * if new value isn't object then just overwrite by new value 120 * instead of extending. 121 */ 122 } else if (typeof val !== 'object' || val === null) { 123 target[key] = val; 124 return; 125 126 // just clone arrays (and recursive clone objects inside) 127 } else if (Array.isArray(val)) { 128 target[key] = deepCloneArray(val); 129 return; 130 131 // custom cloning and overwrite for specific objects 132 } else if (isSpecificValue(val)) { 133 target[key] = cloneSpecificValue(val); 134 return; 135 136 // overwrite by new value if source isn't object or array 137 } else if (typeof src !== 'object' || src === null || Array.isArray(src)) { 138 target[key] = deepExtend({}, val); 139 return; 140 141 // source value and new value is objects both, extending... 142 } else { 143 target[key] = deepExtend(src, val); 144 return; 145 } 146 }); 147 }); 148 149 return target; 150};