The documentation should be updated, it seems optional parameters are inferred based on Swift optionality via ?.
Replace this:
@OptionalParameter(title: "Quantity") var quantity: Int?
with this:
@Parameter(title: "Quantity") var quantity: Int?
The user won't be required to specify the parameter.
Glacials
Users receive reputation points by contributing quality content to the forums.
Posts include post and replies published on the forums.
Post authors can mark replies as Accepted to indicate successful solutions.
Apple Developer Forums admins can mark replies as Apple Recommended to indicate an approved solution
User for
Post
Replies
Boosts
Views
Activity
I'm experiencing what @mrtnmgi describes too—willMigrate and didMigrate are never called. I have it reproducing in a repeatable test which I've attached to FB13711459.
It seems this is related to using CloudKit. See more here: https://forums.developer.apple.com/forums/thread/744491
I came across this while googling and thought I'd also put my solution here for any others it helps:
I was bumping the schema just to use the migrations for ensuring data integrity, and I hadn't actually changed the model. Once I made a change to the model (renamed an attribute I had been meaning to get around to) everything worked fine.