Mongoose findByIdAndUpdate not returning correct model

Question

In Mongoose 4.0, the default value for the new option of findByIdAndUpdate (and findOneAndUpdate) has changed to false, which means returning the old doc (see #2262 of the release notes). So you need to explicitly set the option to true to get the new version of the doc, after the update is applied:

Model.findByIdAndUpdate(id, updateObj, {new: true}, function(err, model) {...