swiftdata-pro

1. Check for core SwiftData issues using

   references/core-rules.md

   .
2. Check that predicates are safe and supported using

   references/predicates.md

   .
3. If the project uses CloudKit, check for CloudKit-specific constraints using

   references/cloudkit.md

   .
4. If the project targets iOS 18+, check for indexing opportunities using

   references/indexing.md

   .
5. If the project targets iOS 26+, check for class inheritance patterns using

   references/class-inheritance.md

   .

Core Instructions

• Target Swift 6.2 or later, using modern Swift concurrency.
• The user strongly prefers to use SwiftData across the board. Do not suggest Core Data functionality unless it is a feature that cannot be solved with SwiftData.
• Do not introduce third-party frameworks without asking first.
• Use a consistent project structure, with folder layout determined by app features.

Output Format

1. State the file and relevant line(s).
2. Name the rule being violated.
3. Show a brief before/after code fix.

Destination.swift

// Before
var sights: [Sight]

// After
@Relationship(deleteRule: .cascade, inverse: \Sight.destination) var sights: [Sight]

isEmpty == false

!

// Before
#Predicate<Destination> { $0.sights.isEmpty == false }

// After
#Predicate<Destination> { !$0.sights.isEmpty }

DestinationListView.swift

@Query

// Before
class DestinationStore {
    @Query var destinations: [Destination]
}

// After
class DestinationStore {
    var modelContext: ModelContext

    func fetchDestinations() throws -> [Destination] {
        try modelContext.fetch(FetchDescriptor<Destination>())
    }
}

Summary

1. Data loss (high): Missing delete rule on line 8 of Destination.swift means sights will be orphaned when a destination is deleted.
2. Crash (high):

   isEmpty == false

   on line 22 will crash at runtime – use

   !isEmpty

   instead.
3. Incorrect behavior (high):

   @Query

   on line 5 of DestinationListView.swift only works inside SwiftUI views.

References

• references/core-rules.md

  - autosaving, relationships, delete rules, property restrictions, and FetchDescriptor optimization.

• references/predicates.md

  - supported predicate operations, dangerous patterns that crash at runtime, and unsupported methods.

• references/cloudkit.md

  - CloudKit-specific constraints including uniqueness, optionality, and eventual consistency.

• references/indexing.md

  - database indexing for iOS 18+, including single and compound property indexes.

• references/class-inheritance.md

  - model subclassing for iOS 26+, including @available requirements, schema setup, and predicate filtering.