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'use strict';
var hasOwn = Object.prototype.hasOwnProperty; var toStr = Object.prototype.toString; var defineProperty = Object.defineProperty; var gOPD = Object.getOwnPropertyDescriptor;
var isArray = function isArray(arr) { if (typeof Array.isArray === 'function') { return Array.isArray(arr); }
return toStr.call(arr) === '[object Array]'; };
var isPlainObject = function isPlainObject(obj) { if (!obj || toStr.call(obj) !== '[object Object]') { return false; }
var hasOwnConstructor = hasOwn.call(obj, 'constructor'); var hasIsPrototypeOf = obj.constructor && obj.constructor.prototype && hasOwn.call(obj.constructor.prototype, 'isPrototypeOf'); // Not own constructor property must be Object
if (obj.constructor && !hasOwnConstructor && !hasIsPrototypeOf) { return false; }
// Own properties are enumerated firstly, so to speed up,
// if last one is own, then all properties are own.
var key; for (key in obj) { /**/ }
return typeof key === 'undefined' || hasOwn.call(obj, key); };
// If name is '__proto__', and Object.defineProperty is available, define __proto__ as an own property on target
var setProperty = function setProperty(target, options) { if (defineProperty && options.name === '__proto__') { defineProperty(target, options.name, { enumerable: true, configurable: true, value: options.newValue, writable: true }); } else { target[options.name] = options.newValue; } };
// Return undefined instead of __proto__ if '__proto__' is not an own property
var getProperty = function getProperty(obj, name) { if (name === '__proto__') { if (!hasOwn.call(obj, name)) { return void 0; } else if (gOPD) { // In early versions of node, obj['__proto__'] is buggy when obj has
// __proto__ as an own property. Object.getOwnPropertyDescriptor() works.
return gOPD(obj, name).value; } }
return obj[name]; };
module.exports = function extend() { var options, name, src, copy, copyIsArray, clone; var target = arguments[0]; var i = 1; var length = arguments.length; var deep = false;
// Handle a deep copy situation
if (typeof target === 'boolean') { deep = target; target = arguments[1] || {}; // skip the boolean and the target
i = 2; } if (target == null || (typeof target !== 'object' && typeof target !== 'function')) { target = {}; }
for (; i < length; ++i) { options = arguments[i]; // Only deal with non-null/undefined values
if (options != null) { // Extend the base object
for (name in options) { src = getProperty(target, name); copy = getProperty(options, name);
// Prevent never-ending loop
if (target !== copy) { // Recurse if we're merging plain objects or arrays
if (deep && copy && (isPlainObject(copy) || (copyIsArray = isArray(copy)))) { if (copyIsArray) { copyIsArray = false; clone = src && isArray(src) ? src : []; } else { clone = src && isPlainObject(src) ? src : {}; }
// Never move original objects, clone them
setProperty(target, { name: name, newValue: extend(deep, clone, copy) });
// Don't bring in undefined values
} else if (typeof copy !== 'undefined') { setProperty(target, { name: name, newValue: copy }); } } } } }
// Return the modified object
return target; };
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