apple-patterns-check

Apple Patterns Check

Fast validation that code follows Apple's documented patterns. Uses shell commands to detect violations before they reach CI.

When to Use

• Before committing significant Swift changes
• During /ship — after implement, before archive
• When reviewing code touching SwiftUI, SwiftData, or concurrency
• When unsure "is this the Apple way?"

Quick Check

/apple-check
/apple-check src/ViewModels/
/apple-check --since-last-commit

Pattern Validation

1. Swift 6 Concurrency Patterns

# 1.1 Task @MainActor annotation — CRITICAL: crash risk
# All Task { [weak self] must be Task { @MainActor [weak self]
git diff HEAD --name-only -- "*.swift" | xargs grep -n "Task { \[weak self\]" 2>/dev/null | grep -v "@MainActor"

# 1.2 @preconcurrency import — OBSOLETE CHECK (2026-04-03)
# iOS 26 first-party frameworks are Sendable-annotated. Prophylactic @preconcurrency
# masks real concurrency issues. Only add where compiler specifically demands it.
# This check is kept for legacy/third-party modules only.
# git diff HEAD --name-only -- "*.swift" | xargs grep -n "^import SomeLegacyModule" 2>/dev/null | grep -v "@preconcurrency"

# 1.3 Double @MainActor (crash risk if SWIFT_DEFAULT_ACTOR_ISOLATION = MainActor)
# If the build setting is already MainActor, remove explicit @MainActor from class declarations
grep -rn "@MainActor" . --include="*.swift" | grep "class " | head -20

1.5 nonisolated deinit — CRITICAL: crash risk for @MainActor classes

Any @MainActor class with deinit that doesn't say nonisolated will crash

grep -rn "deinit" . --include="*.swift" | grep -v "nonisolated|Tests|// no-cleanup"

If the class is @MainActor (explicit or via SWIFT_DEFAULT_ACTOR_ISOLATION), deinit MUST be nonisolated

1.6 FoundationModels isAvailable must NOT be hardcoded — CRITICAL: crash on non-AI devices

grep -rn "isAvailable.return true|isAvailable.=.true" . --include=".swift" | grep -iv "test|mock|preview"

Expected: 0 results — must use SystemLanguageModel.default.isAvailable