1. Run bundle

2. load page and add a name to calendar and click submit

3. Then check your MongoDB database named ‘mongoid_test’

> use mongoid_test switched to db mongoid_test > show collections calendars users > db.users.find() { “_id” : ObjectId(“5d50e2783ed14966a0000000”), “updated_at” : ISODate(“2019-08-12T03:54:08.466Z”), “created_at” : ISODate(“2019-08-12T03:52:24.036Z”) } > db.calendars.find() { “_id” : ObjectId(“5d50e2e03ed14966a0000002”), “_type” : “SharedCalendar”, “name” : “something cool”, “user_ids” : [ ObjectId(“5d50e2783ed14966a0000000”) ], “updated_at” : ISODate(“2019-08-12T03:54:08.446Z”), “created_at” : ISODate(“2019-08-12T03:54:08.446Z”) }

The Issue:

When creating the Shared Calendar, it did not update the shared_calendar_ids field in the user document. In other words, it only saved the many to many relation in one direction, not both directions.