iOS App Quality

Testing, privacy, performance profiling, and distribution patterns for shipping iOS/watchOS health apps.

• reference.md — long-form explanations (manifests, Instruments, multi-target, CI/CD, StoreKit, HIG, setup)
• examples.md — complete code (Swift, XML, Ruby)

When to Use

• Writing unit and integration tests for HealthKit-dependent code
• Designing privacy-first data architecture
• Profiling battery and memory usage with Instruments
• Preparing for App Store review (health app scrutiny)
• Setting up CI/CD and TestFlight distribution

HealthKit Mocking

Abstract HKHealthStore behind a HealthStore protocol so tests inject a MockHealthStore tracking authorization, saved samples, and errors. See examples.md § HealthKit Mocking for Tests for the protocol + Live + Mock.

Testing Frameworks

Swift Testing: @Suite, @Test, #expect, parameterized with arguments:. XCTest: setUp/tearDown, XCTAssert*, test__method__condition__expected. See examples.md § Swift Testing Framework (Modern) and examples.md § XCTest (Traditional).

Privacy Architecture

Store only aggregates in SwiftData — raw samples escape via iCloud backup, breaking the privacy model the HealthKit usage description claimed. Keychain for sensitive preferences. See reference.md § Privacy Manifest (PrivacyInfo.xcprivacy) and examples.md § Privacy-First Data Architecture.

Performance Profiling (Instruments)

See reference.md § Performance Profiling (Instruments) for per-instrument guidance.

App Store Review Checklist (Health Apps)

Health apps face heightened scrutiny for medical claims, missing privacy manifests, and off-device data transmission. See reference.md § App Store Review Checklist (Health Apps) for the 10-item checklist.

Design Wireframe Validation

Two-pass review: pass 1 validates fidelity scope and Reduce Motion alternatives; pass 2 checks HIG compliance (safe areas, 44pt touch targets, watchOS 13pt font minimum). See reference.md § Design Wireframe Validation.

Pre-Sprint Setup Items

Three lead-time items: PrivacyInfo.xcprivacy build phase placement (silent rejection without it), increased-memory-limit entitlement approval (1-3 business days), and watchOS WKBackgroundModes for workout sessions. See reference.md § Pre-Sprint Setup Items.

Font Bundling

Custom fonts require TTF files in Resources/Fonts/, UIAppFonts filenames in Info.plist, and PostScript name verification — filename and PostScript name routinely differ, causing silent system-font fallback. watchOS has no custom font registration. See reference.md § Font Bundling for licensing, SHA-256 verification, and Google Fonts CDN discovery.

SourceKit Diagnostic Reliability

SourceKit "Cannot find type" / "No such module" errors are frequently stale in multi-target projects — a successful xcodebuild build means the diagnostics are phantom. See reference.md § SourceKit Diagnostic Reliability in Multi-Target Projects.

Privacy Manifests (NSPrivacyAccessedAPITypes)

SwiftData apps declare NSPrivacyAccessedAPICategoryFileTimestamp (C617.1) and NSPrivacyAccessedAPICategoryDiskSpace (E174.1); mismatched UserDefaults reason codes cause rejection. See reference.md § NSPrivacyAccessedAPITypes for SwiftData apps for the reason-code matrix and Privacy Report workflow.

CI/CD & Code Signing

HealthKit requires an explicit App ID (no wildcard). Use Xcode automatic signing or Fastlane match; Xcode Cloud or Fastlane for build-test-archive-deploy to TestFlight. See reference.md § CI/CD & Code Signing and examples.md § Xcode Cloud Workflow.

StoreKit 2

Product.products(for:) loads, Transaction.currentEntitlements checks subs, product.purchase() purchases — transaction.finish() is required or transactions retry indefinitely. Use .storekit files for local testing. See examples.md § StoreKit 2 (Subscriptions).

SwiftData & HealthKit Error Handling

try? on modelContext.fetch() causes fetchOrCreate duplicates; same for HKWorkoutBuilder.finishWorkout() — session data lost silently. Use do/catch with os_log(.error). See examples.md § SwiftData & HealthKit Error Handling: try? vs do/catch.

SwiftData iCloud Backup Exclusion

Excluding only .store leaves .store-shm and .store-wal WAL files still backing up — exclude all three in App.init() and scenePhase .active to cover the first-launch materialization race. See examples.md § SwiftData iCloud Backup Exclusion.

Privacy-Critical Logging

Privacy-critical paths use os.Logger .fault() with .public labels — production silences print(), so only Logger.fault surfaces in Console.app. See examples.md § Privacy-Critical Logging (os.Logger).

SwiftData Test Container Retention

ModelContext does not retain its container — a helper returning only the manager lets the container dealloc and the next fetch crashes with EXC_BAD_ACCESS. Return a (Manager, ModelContainer) tuple; bind both. See examples.md § SwiftData Test Container Retention.

Swift Testing Conventions (SwiftLint + SwiftFormat)

Two pre-commit blockers: @Suite(.serialized) not @Suite("string-name", .serialized) (swiftTestingTestCaseNames rejects string labels), and identifiers ≥3 chars (pm, vm, id fail). See reference.md § Swift Testing Conventions (SwiftLint + SwiftFormat) for rule interactions and type-body-length split strategy.

git add -f for Gitignored Sprint Folders

Sprint folders gitignored per AIEE hub convention need git add -f sprint/path/to/ticket.md to include implementation notes in the PR. Document the force-add in the description. See reference.md § git add -f for Gitignored Sprint Folders.

Anti-Patterns

Key References

• App Store Review Guidelines: Health
• HealthKit Entitlement docs
• Privacy Manifest docs
• StoreKit 2 documentation
• Xcode Cloud documentation