watchOS Code Review

Quick Reference

Issue Type Reference

App lifecycle, scenes, background modes, extended runtime references/lifecycle.md

ClockKit, WidgetKit, timeline providers, Smart Stack references/complications.md

WCSession, message passing, file transfer, reachability references/connectivity.md

Memory limits, background refresh, battery optimization references/performance.md

Review Checklist

• SwiftUI App protocol used with @WKApplicationDelegateAdaptor for lifecycle events

• scenePhase read from root view (not sheets/modals where it's always .active )

• WKExtendedRuntimeSession started only while app is active (not from background)

• Workout sessions recovered in applicationDidFinishLaunching (not just delegate)

• Background tasks scheduled at least 5 minutes apart; next scheduled before completing current

• URLSessionDownloadTask (not DataTask ) used for background network requests

• WidgetKit used instead of ClockKit for watchOS 9+ complications

• Timeline includes future entries (not just current state); gaps avoided

• TimelineEntryRelevance implemented for Smart Stack prioritization

• WCSession delegate set before activate() ; singleton pattern used

• isReachable checked before sendMessage ; transferUserInfo for critical data

• Received files moved synchronously before delegate callback returns

When to Load References

• Reviewing app lifecycle, background modes, or extended sessions -> lifecycle.md

• Reviewing complications, widgets, or timeline providers -> complications.md

• Reviewing WCSession, iPhone-Watch communication -> connectivity.md

• Reviewing memory, battery, or performance issues -> performance.md

Review Questions

• Is the app using modern SwiftUI lifecycle with delegate adaptor?

• Are background tasks completing properly (calling setTaskCompletedWithSnapshot )?

• Is UI update frequency reduced when isLuminanceReduced is true?

• Are WatchConnectivity delegate callbacks dispatching to main thread?

• Is TabView nested within another TabView ? (Memory leak on watchOS)