blob: f8aeac59165511ccf6866779bb1ffbc56b23a0be [file] [log] [blame]
var arrayCopy = require('./arrayCopy'),
isArguments = require('../lang/isArguments'),
isArray = require('../lang/isArray'),
isArrayLike = require('./isArrayLike'),
isPlainObject = require('../lang/isPlainObject'),
isTypedArray = require('../lang/isTypedArray'),
toPlainObject = require('../lang/toPlainObject');
/**
* A specialized version of `baseMerge` for arrays and objects which performs
* deep merges and tracks traversed objects enabling objects with circular
* references to be merged.
*
* @private
* @param {Object} object The destination object.
* @param {Object} source The source object.
* @param {string} key The key of the value to merge.
* @param {Function} mergeFunc The function to merge values.
* @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 {boolean} Returns `true` if the objects are equivalent, else `false`.
*/
function baseMergeDeep(object, source, key, mergeFunc, customizer, stackA, stackB) {
var length = stackA.length,
srcValue = source[key];
while (length--) {
if (stackA[length] == srcValue) {
object[key] = stackB[length];
return;
}
}
var value = object[key],
result = customizer ? customizer(value, srcValue, key, object, source) : undefined,
isCommon = result === undefined;
if (isCommon) {
result = srcValue;
if (isArrayLike(srcValue) && (isArray(srcValue) || isTypedArray(srcValue))) {
result = isArray(value)
? value
: (isArrayLike(value) ? arrayCopy(value) : []);
}
else if (isPlainObject(srcValue) || isArguments(srcValue)) {
result = isArguments(value)
? toPlainObject(value)
: (isPlainObject(value) ? value : {});
}
else {
isCommon = false;
}
}
// Add the source value to the stack of traversed objects and associate
// it with its merged value.
stackA.push(srcValue);
stackB.push(result);
if (isCommon) {
// Recursively merge objects and arrays (susceptible to call stack limits).
object[key] = mergeFunc(result, srcValue, customizer, stackA, stackB);
} else if (result === result ? (result !== value) : (value === value)) {
object[key] = result;
}
}
module.exports = baseMergeDeep;