blob: ab81900869153d592ee30ecfc4265ab7d2bef0c2 [file] [log] [blame]
var arrayEach = require('./arrayEach'),
baseMergeDeep = require('./baseMergeDeep'),
isArray = require('../lang/isArray'),
isArrayLike = require('./isArrayLike'),
isObject = require('../lang/isObject'),
isObjectLike = require('./isObjectLike'),
isTypedArray = require('../lang/isTypedArray'),
keys = require('../object/keys');
/**
* The base implementation of `_.merge` without support for argument juggling,
* multiple sources, and `this` binding `customizer` functions.
*
* @private
* @param {Object} object The destination object.
* @param {Object} source The source object.
* @param {Function} [customizer] The function to customize merged values.
* @param {Array} [stackA=[]] Tracks traversed source objects.
* @param {Array} [stackB=[]] Associates values with source counterparts.
* @returns {Object} Returns `object`.
*/
function baseMerge(object, source, customizer, stackA, stackB) {
if (!isObject(object)) {
return object;
}
var isSrcArr = isArrayLike(source) && (isArray(source) || isTypedArray(source)),
props = isSrcArr ? undefined : keys(source);
arrayEach(props || source, function(srcValue, key) {
if (props) {
key = srcValue;
srcValue = source[key];
}
if (isObjectLike(srcValue)) {
stackA || (stackA = []);
stackB || (stackB = []);
baseMergeDeep(object, source, key, baseMerge, customizer, stackA, stackB);
}
else {
var value = object[key],
result = customizer ? customizer(value, srcValue, key, object, source) : undefined,
isCommon = result === undefined;
if (isCommon) {
result = srcValue;
}
if ((result !== undefined || (isSrcArr && !(key in object))) &&
(isCommon || (result === result ? (result !== value) : (value === value)))) {
object[key] = result;
}
}
});
return object;
}
module.exports = baseMerge;