Migration Patterns

Comprehensive guides for migrating between Apple framework generations. Each guide covers the full before/after mapping, coexistence strategies, and common pitfalls.

When This Skill Activates

• User asks how to migrate from CoreData to SwiftData
• User is moving UIKit code to SwiftUI (or embedding one in the other)
• User needs to update from ObservableObject/Combine to @Observable/AsyncSequence
• User is converting XCTest tests to Swift Testing
• User asks about coexistence strategies (running old and new frameworks side by side)
• User wants to know whether a migration is worth doing for their situation
• User is migrating Objective-C code to Swift (bridging headers, incremental migration)
• User is migrating from StoreKit 1 to StoreKit 2 (in-app purchases, subscriptions)
• User encounters errors during a framework migration

Decision Tree