1 var arrayEach = require('./arrayEach'),
2 baseMergeDeep = require('./baseMergeDeep'),
3 getSymbols = require('./getSymbols'),
4 isArray = require('../lang/isArray'),
5 isLength = require('./isLength'),
6 isObject = require('../lang/isObject'),
7 isObjectLike = require('./isObjectLike'),
8 isTypedArray = require('../lang/isTypedArray'),
9 keys = require('../object/keys');
11 /** Used for native method references. */
12 var arrayProto = Array.prototype;
14 /** Native method references. */
15 var push = arrayProto.push;
18 * The base implementation of `_.merge` without support for argument juggling,
19 * multiple sources, and `this` binding `customizer` functions.
22 * @param {Object} object The destination object.
23 * @param {Object} source The source object.
24 * @param {Function} [customizer] The function to customize merging properties.
25 * @param {Array} [stackA=[]] Tracks traversed source objects.
26 * @param {Array} [stackB=[]] Associates values with source counterparts.
27 * @returns {Object} Returns `object`.
29 function baseMerge(object, source, customizer, stackA, stackB) {
30 if (!isObject(object)) {
33 var isSrcArr = isLength(source.length) && (isArray(source) || isTypedArray(source));
35 var props = keys(source);
36 push.apply(props, getSymbols(source));
38 arrayEach(props || source, function(srcValue, key) {
41 srcValue = source[key];
43 if (isObjectLike(srcValue)) {
44 stackA || (stackA = []);
45 stackB || (stackB = []);
46 baseMergeDeep(object, source, key, baseMerge, customizer, stackA, stackB);
49 var value = object[key],
50 result = customizer ? customizer(value, srcValue, key, object, source) : undefined,
51 isCommon = result === undefined;
56 if ((isSrcArr || result !== undefined) &&
57 (isCommon || (result === result ? (result !== value) : (value === value)))) {
65 module.exports = baseMerge;