databaseUUIDEncodingStrategy(for:) not called when using Tagged<Self, UUID> to define my id

[yqiang]

I'm in the process of migrating UUID columns from being stored as a BLOB to TEXT and noticed that the static databaseUUIDEncodingStrategy method on my record type wasn't being called. My record is declared like this:

public struct MyModel: Codable, Identifiable, Hashable, Sendable {
  public typealias ID = Tagged<Self, UUID>
  public var id: ID
...

and I'd like to encode the UUIDs as lowercased strings, so I implemented:

  public static func databaseUUIDEncodingStrategy(for column: String) -> DatabaseUUIDEncodingStrategy {
    .lowercaseString
  }

However this method is never called. If I remove the use of Tagged and just mark id as UUID, things work as expected. I'm not sure if this is expected behavior, and what if anything I could do to work around this.

I'm integrating the Tagged library with GRDB like so:

import GRDB
import Tagged

extension Tagged: GRDB.SQLExpressible where RawValue: GRDB.SQLExpressible {}
extension Tagged: GRDB.StatementBinding where RawValue: GRDB.StatementBinding {}
extension Tagged: GRDB.StatementColumnConvertible where RawValue: GRDB.StatementColumnConvertible {}
extension Tagged: GRDB.DatabaseValueConvertible where RawValue: GRDB.DatabaseValueConvertible {}

[yqiang]

I was able to get something working by doing this:

extension Tagged: GRDB.DatabaseValueConvertible where RawValue: GRDB.DatabaseValueConvertible {
  public var databaseValue: DatabaseValue {
    if let rawValue = self.rawValue as? UUID {
      return rawValue.uuidString.lowercased().databaseValue
    }
    
    return self.rawValue.databaseValue
  }
  
  public static func fromDatabaseValue(_ dbValue: DatabaseValue) -> Tagged<Tag, RawValue>? {
    if RawValue.self is UUID.Type {
      guard let string = String.fromDatabaseValue(dbValue),
            let uuid = UUID(uuidString: string) else {
        return nil
      }
      return Tagged(rawValue: uuid as! RawValue)
    }
    
    guard let rawValue = RawValue.fromDatabaseValue(dbValue) else {
      return nil
    }
    return Tagged(rawValue: rawValue)
  }
}

However this means that all UUIDs must be lowercased strings now and I lose the ability to customize it on a per table / per column basis. Hopefully there's a better solution to this that is escaping me at the moment.