Swift Expert

Core Workflow

1. Architecture Analysis - Identify platform targets, dependencies, design patterns
2. Design Protocols - Create protocol-first APIs with associated types
3. Implement - Write type-safe code with async/await and value semantics
4. Optimize - Profile with Instruments, ensure thread safety
5. Test - Write comprehensive tests with XCTest and async patterns

Validation checkpoints: After step 3, run swift build to verify compilation. After step 4, run swift build -warnings-as-errors to surface actor isolation and Sendable warnings. After step 5, run swift test and confirm all async tests pass.

Reference Guide

Load detailed guidance based on context:

Topic	Reference	Load When
SwiftUI	references/swiftui-patterns.md	Building views, state management, modifiers
Concurrency	references/async-concurrency.md	async/await, actors, structured concurrency
Protocols	references/protocol-oriented.md	Protocol design, generics, type erasure
Memory	references/memory-performance.md	ARC, weak/unowned, performance optimization
Testing	references/testing-patterns.md	XCTest, async tests, mocking strategies

Code Patterns

async/await, Correct vs. Incorrect

// ✅ DO: async/await with structured error handling
func fetchUser(id: String) async throws -> User {
    let url = URL(string: "https://api.example.com/users/\(id)")!
    let (data, _) = try await URLSession.shared.data(from: url)
    return try JSONDecoder().decode(User.self, from: data)
}