Combine Code Review

Quick Reference

Issue Type Reference

Publishers, Subjects, AnyPublisher references/publishers.md

map, flatMap, combineLatest, switchToLatest references/operators.md

AnyCancellable, retain cycles, [weak self] references/memory.md

tryMap, catch, replaceError, Never references/error-handling.md

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

• Are all subscriptions being retained? (Check for discarded AnyCancellables)

• Could any sink or assign create a retain cycle with self?

• Does flatMap need to be switchToLatest for search/autocomplete?

• What happens when this publisher fails? (Will it kill the main chain?)

• Are error types preserved or properly mapped after try* operators?