fusengine Swift Core
Swift 6 fundamentals shared across all Apple platforms.
Agent Workflow (MANDATORY)
Before ANY implementation, use TeamCreate to spawn 3 agents:
- fuse-ai-pilot:explore-codebase - Analyze existing Swift patterns
- fuse-ai-pilot:research-expert - Verify latest Swift 6 docs via Context7/Exa
- mcp__apple-docs__search_apple_docs - Check Swift concurrency patterns
After implementation, run fuse-ai-pilot:sniper for validation.
Overview
When to Use
- Implementing async/await, actors, Sendable
- Designing app architecture (MVVM, Clean Architecture)
- Writing async tests with XCTest
- Localizing with String Catalogs
- Profiling with Instruments
Why Swift Core
| Feature | Benefit |
|---|---|
| Actors | Thread-safe shared state without locks |
| @Observable | Simple reactive state (replaces ObservableObject) |
| String Catalogs | Automatic localization with Xcode 15+ |
| Instruments | Built-in performance profiling |
Key Concepts
Concurrency (Swift 6)
Modern async/await with strict concurrency checking. Actors provide thread-safe state, Sendable marks safe types.
Architecture
MVVM with @Observable is the recommended pattern. Clean Architecture for complex apps with domain separation.
Testing
XCTest with native async/await support. No need for expectations with async tests.
Internationalization
String Catalogs are mandatory. All user-facing text must be localized.
Performance
Profile with Instruments. Use lazy loading, avoid heavy work in view body.
Reference Guide
| Need | Reference |
|---|---|
| Async/await, actors, Sendable | concurrency.md |
| MVVM, Clean Architecture, DI | architecture.md |
| XCTest, async tests, mocking | testing.md |
| String Catalogs, localization | i18n.md |
| Instruments, optimization | performance.md |
Best Practices
- Actors for shared state - Prefer actors over classes with locks
- @Observable over ObservableObject - Simpler, better performance
- Structured concurrency - async/await, no completion handlers
- String Catalogs - ALL user-facing text must be localized
- Profile in Release - Always profile with
-Ooptimization - Value types - Prefer structs over classes