My app under development uses core data.
When I add an optional attribute to an entity, I expected that automatic lightweight migration is done, because I use an NSPersistentCloudKitContainer, and all my NSPersistentStoreDescription have the default settings shouldMigrateStoreAutomatically = true and shouldInferMappingModelAutomatically = true.
After changing the xcdatamodeld file by adding an attribute and restarting the app with the old persistent store, no data is fetched, and no error is reported.
However when I re-install the app, everything works fine, because a new persistent store is filled with the iCloud data.
Maybe I can detect that the model has changed, delete the old persistent store, and setup a new one that is synced then with iCloud.
But it should also work without iCloud sync: I thought the old persistent store should be automatically migrated to the new model, i.e., the newly added attribute should be initialized with nil.
Is this a misunderstanding? Do I miss something? How to do the migration correctly?
PS: I have read this answer, but since my app is still under development, I thought I don't need different versions of the model, but could simply update it.
