documentit/node_modules/deep-extend/lib/deep-extend.js
2018-01-05 10:48:13 -08:00

145 lines
4.0 KiB
JavaScript

/*!
* @description Recursive object extending
* @author Viacheslav Lotsmanov <lotsmanov89@gmail.com>
* @license MIT
*
* The MIT License (MIT)
*
* Copyright (c) 2013-2015 Viacheslav Lotsmanov
*
* Permission is hereby granted, free of charge, to any person obtaining a copy of
* this software and associated documentation files (the "Software"), to deal in
* the Software without restriction, including without limitation the rights to
* use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
* the Software, and to permit persons to whom the Software is furnished to do so,
* subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in all
* copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
* FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
* COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
* IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/
'use strict';
function isSpecificValue(val) {
return (
val instanceof Buffer
|| val instanceof Date
|| val instanceof RegExp
) ? true : false;
}
function cloneSpecificValue(val) {
if (val instanceof Buffer) {
var x = new Buffer(val.length);
val.copy(x);
return x;
} else if (val instanceof Date) {
return new Date(val.getTime());
} else if (val instanceof RegExp) {
return new RegExp(val);
} else {
throw new Error('Unexpected situation');
}
}
/**
* Recursive cloning array.
*/
function deepCloneArray(arr) {
var clone = [];
arr.forEach(function (item, index) {
if (typeof item === 'object' && item !== null) {
if (Array.isArray(item)) {
clone[index] = deepCloneArray(item);
} else if (isSpecificValue(item)) {
clone[index] = cloneSpecificValue(item);
} else {
clone[index] = deepExtend({}, item);
}
} else {
clone[index] = item;
}
});
return clone;
}
/**
* Extening object that entered in first argument.
*
* Returns extended object or false if have no target object or incorrect type.
*
* If you wish to clone source object (without modify it), just use empty new
* object as first argument, like this:
* deepExtend({}, yourObj_1, [yourObj_N]);
*/
var deepExtend = module.exports = function (/*obj_1, [obj_2], [obj_N]*/) {
if (arguments.length < 1 || typeof arguments[0] !== 'object') {
return false;
}
if (arguments.length < 2) {
return arguments[0];
}
var target = arguments[0];
// convert arguments to array and cut off target object
var args = Array.prototype.slice.call(arguments, 1);
var val, src, clone;
args.forEach(function (obj) {
// skip argument if isn't an object, is null, or is an array
if (typeof obj !== 'object' || obj === null || Array.isArray(obj)) {
return;
}
Object.keys(obj).forEach(function (key) {
src = target[key]; // source value
val = obj[key]; // new value
// recursion prevention
if (val === target) {
return;
/**
* if new value isn't object then just overwrite by new value
* instead of extending.
*/
} else if (typeof val !== 'object' || val === null) {
target[key] = val;
return;
// just clone arrays (and recursive clone objects inside)
} else if (Array.isArray(val)) {
target[key] = deepCloneArray(val);
return;
// custom cloning and overwrite for specific objects
} else if (isSpecificValue(val)) {
target[key] = cloneSpecificValue(val);
return;
// overwrite by new value if source isn't object or array
} else if (typeof src !== 'object' || src === null || Array.isArray(src)) {
target[key] = deepExtend({}, val);
return;
// source value and new value is objects both, extending...
} else {
target[key] = deepExtend(src, val);
return;
}
});
});
return target;
}