Swift Code Review

Quick Reference

Review Checklist

• No force unwraps (!) on runtime data (network, user input, files)
• Closures stored as properties use [weak self]
• Delegate properties are weak
• Independent async operations use async let or TaskGroup
• Long-running Tasks check Task.isCancelled
• Actors have mutable state to protect (no stateless actors)
• Sendable types are truly thread-safe (beware @unchecked)
• Errors handled explicitly (no empty catch blocks)
• Custom errors conform to LocalizedError with descriptive messages
• Nested @Observable objects are also marked @Observable
• @Bindable used for two-way bindings to Observable objects

When to Load References

• Reviewing async/await, actors, or TaskGroups → concurrency.md
• Reviewing @Observable or SwiftUI state → observable.md
• Reviewing error handling or throws → error-handling.md
• General Swift review → common-mistakes.md

Review Questions

1. Are async operations that could run concurrently using async let?
2. Could actor state change across suspension points (reentrancy bug)?
3. Is @unchecked Sendable backed by actual synchronization?
4. Are errors logged and presented with helpful context?
5. Could any closure or delegate create a retain cycle?