name: combine-code-review
description: Reviews Combine framework code for memory leaks, operator misuse, and error handling. Use when reviewing code with import Combine, AnyPublisher, @Published, PassthroughSubject, or CurrentValueSubject.

Combine Code Review

Quick Reference

Review Checklist

• [ ] All sink closures use [weak self] when self owns cancellable
• [ ] No assign(to:on:self) usage (use assign(to: &$property) or sink)
• [ ] All AnyCancellables stored in Set or property (not discarded)
• [ ] Subjects exposed as AnyPublisher via eraseToAnyPublisher()
• [ ] flatMap used correctly (not when map + switchToLatest needed)
• [ ] Error handling inside flatMap to keep main chain alive
• [ ] tryMap followed by mapError to restore error types
• [ ] receive(on: DispatchQueue.main) before UI updates
• [ ] PassthroughSubject for events, CurrentValueSubject for state
• [ ] Future wrapped in Deferred when used with retry

When to Load References

• Reviewing Subjects or publisher selection → publishers.md
• Reviewing operator chains or combining publishers → operators.md
• Reviewing subscriptions or memory issues → memory.md
• Reviewing error handling or try* operators → error-handling.md

Review Questions

1. Are all subscriptions being retained? (Check for discarded AnyCancellables)
2. Could any sink or assign create a retain cycle with self?
3. Does flatMap need to be switchToLatest for search/autocomplete?
4. What happens when this publisher fails? (Will it kill the main chain?)
5. Are error types preserved or properly mapped after try* operators?