name : _customDefaultsAssignIn.js 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;