/**
* @module
*/
var ObjectId = require('mongoose').Types.ObjectId;
/**
* Return given properties with all references unpopulated
* @param {Object} properties
*/
module.exports = function(properties) {
var unpopulatedProperties = {};
Object.keys(properties).forEach((key) => {
if (typeof properties[key] === 'object' && ObjectId.isValid(properties[key]._id)) {
unpopulatedProperties[key] = properties[key]._id;
} else {
unpopulatedProperties[key] = properties[key];
}
});
return unpopulatedProperties;
};