SwiftData Schema Changes Need Migration Tests
An app updates its local data model while existing users have old stores. This guide gives you a small, testable way to approach the issue before changing a live system.
A practical workflow
- Keep model changes explicit and create a migration plan for incompatible versions.
- Install the old build, create records, update to the new build and check them.
What to check
A clean install does not test migration; preserve realistic old data fixtures. Compare the result with the original problem and record what changed. If a measurement or test does not support the change, revisit the assumption rather than adding more complexity.
Keep the experiment small enough to reverse. Document the starting state, the change and the result so another person can repeat the process. Product menus and versions can change, so check the current documentation for your environment.
Official reference: Read the documentation.