mongoid-embedded-errors

https://github.com/glooko/mongoid-embedded-errors

Embedded documents in Mongoid can be really useful. However, when one of those embedded documents is invalid, Mongoid does not say which validation has failed. Instead of just saying that an embedded document is invalid, this gem modifies Mongoid behavior so it explicitly provides validation errors on a per-field basis for embedded documents, the same way it does for parent documents.