lucasderraugh / swiftuifetchrequestbug Goto Github PK

When a SwiftUI View is presented that uses @FetchRequest and an update occurs while it is presented, it forever retains the backing SwiftUI.FetchController. This is a problem if you go to remove the persistent stores as creating a new persistent store and having changes on that will crash the outstanding fetch controller that has stale assets.

1. Tap "Open SwiftUI View" (At this point observe in memory debugger that 1 instance of SwiftUI.FetchController exists without a retain cycle)
2. Tap "Add new person" in sheet (Now that same object exists but now has a retain cycle)
3. Dismiss the sheet by swiping down
4. Tap Clear DB (wait for "Persistent stores reloaded" in console)
5. Tap "Open SwiftUI View"
6. Tap "Add new person" in sheet (Observe Core Data throwing an exception)

Before Adding Entity	After Adding Entity