HealthKit Code Review
Quick Reference
| Issue Type | Reference |
|---|---|
| HKHealthStore, permissions, status checks, privacy | references/authorization.md |
| HKQuery types, predicates, anchored queries, statistics | references/queries.md |
| Background delivery, observer queries, completion handlers | references/background.md |
| HKQuantityType, HKCategoryType, workouts, units | references/data-types.md |
Review Checklist
-
HKHealthStore.isHealthDataAvailable()called before any HealthKit operations - Authorization requested only for needed data types (minimal permissions)
-
requestAuthorizationcompletion handler not misinterpreted as permission granted - No attempt to determine read permission status (privacy by design)
- Query results dispatched to main thread for UI updates
-
HKObjectQueryNoLimitused only with bounded predicates -
HKStatisticsQueryused for aggregations instead of manual summing - Observer query
completionHandler()always called (usedefer) - Background delivery registered in
application(_:didFinishLaunchingWithOptions:) - Background delivery entitlement added (iOS 15+)
- Correct units used for quantity types (e.g.,
count/minfor heart rate) - Long-running queries stored as properties and stopped in
deinit
When to Load References
- Reviewing authorization/permissions flow -> authorization.md
- Reviewing HKSampleQuery, HKAnchoredObjectQuery, or predicates -> queries.md
- Reviewing HKObserverQuery or
enableBackgroundDelivery-> background.md - Reviewing HKQuantityType, HKCategoryType, or HKWorkout -> data-types.md
Review Questions
- Is
isHealthDataAvailable()checked before creating HKHealthStore? - Does the code gracefully handle denied permissions (empty results)?
- Are observer query completion handlers called in all code paths?
- Is work in background handlers minimal (~15 second limit)?
- Are HKQueryAnchors persisted per sample type (not shared)?
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