var eq = require('./eq');
/** Used for built-in method references. */
var objectProto = Object.prototype;
/** Used to check objects for own properties. */
var hasOwnProperty = objectProto.hasOwnProperty;
/**
* Used by `_.defaults` to customize its `_.assignIn` use to assign properties
* of source objects to the destination object for all destination properties
* that resolve to `undefined`.
*
* @private
* @param {*} objValue The destination value.
* @param {*} srcValue The source value.
* @param {string} key The key of the property to assign.
* @param {Object} object The parent object of `objValue`.
* @returns {*} Returns the value to assign.
*/
function customDefaultsAssignIn(objValue, srcValue, key, object) {
if (objValue === undefined ||
(eq(objValue, objectProto[key]) && !hasOwnProperty.call(object, key))) {
return srcValue;
}
return objValue;
}
module.exports = customDefaultsAssignIn;