Test doubles for Core Data managed objects might not work as expected
You don’t have to learn anything new if you work with Core Data in Swift. It’s a pain to use NSManagedObject
directly, so you better work with custom subclasses all the time. Unboxing optional NSNumber
s is just too cumbersome. There are caveats you should be aware of, though: Swift’s static typing makes it a bit harder to write test doubles for managed objects.