We add another feature to our SQLiteData-based app to show how the tools interact with observable models and SwiftUI view lifecycles. We’ll show how the library gives you ultimate control over the precision and performance of how data is fetched and loaded in your app.

We give a tour of our SQLiteData library, a fast and lightweight alternative to SwiftData. We’ll set up a fresh project with the package, define models and configure the database, and even write SQL migrations with the help of Xcode’s Coding Assistant.

We continue our series on “modern persistence” with an important topic: “callbacks.” Callbacks are little hooks into the lifecycle of your data model so that you can be notified or take action when something changes. We will first explore the “Active Record” pattern of callbacks, popularized by Ruby on Rails, and then see how we can improve upon them.

We clean up our test suite and make use of the expectDifference helper, for precisely describing changes to state in an exhaustive fashion. We will then rapidly add test coverage using the forthcoming “Point-Free Way” skills documents. Finally, we will achieve the seemingly impossible by writing a test against iCloud sharing!

SQLiteData is incredibly test-friendly. We will show how to configure a test suite for your data layer, how to seed the database for testing, how to assert against this data as it changes, how to employ expectNoDifference for better debugging over Swift Testing’s #expect macro, and how to control the uuid() function used by SQLite.

We’ve extended the tour with a few bonus episodes that show how SQLiteData integrates with Xcode previews and tests! No need to painstakingly mock your persistence layer: previews actually hit the database, and the library automatically supplies a mock CloudKit sync engine so you can easily preview how iCloud sharing looks in your UI.