var baseRest = require('./_baseRest'),
eq = require('./eq'),
isIterateeCall = require('./_isIterateeCall'),
keysIn = require('./keysIn');
/** Used for built-in method references. */
var objectProto = Object.prototype;
/** Used to check objects for own properties. */
var hasOwnProperty = objectProto.hasOwnProperty;
/**
* Assigns own and inherited enumerable string keyed properties of source
* objects to the destination object for all destination properties that
* resolve to `undefined`. Source objects are applied from left to right.
* Once a property is set, additional values of the same property are ignored.
*
* **Note:** This method mutates `object`.
*
* @static
* @since 0.1.0
* @memberOf _
* @category Object
* @param {Object} object The destination object.
* @param {...Object} [sources] The source objects.
* @returns {Object} Returns `object`.
* @see _.defaultsDeep
* @example
*
* _.defaults({ 'a': 1 }, { 'b': 2 }, { 'a': 3 });
* // => { 'a': 1, 'b': 2 }
*/
var defaults = baseRest(function(object, sources) {
object = Object(object);
var index = -1;
var length = sources.length;
var guard = length > 2 ? sources[2] : undefined;
if (guard && isIterateeCall(sources[0], sources[1], guard)) {
length = 1;
}
while (++index < length) {
var source = sources[index];
var props = keysIn(source);
var propsIndex = -1;
var propsLength = props.length;
while (++propsIndex < propsLength) {
var key = props[propsIndex];
var value = object[key];
if (value === undefined ||
(eq(value, objectProto[key]) && !hasOwnProperty.call(object, key))) {
object[key] = source[key];
}
}
}
return object;
});
module.exports = defaults;