Moai Lang Swift

Swift 6+ Development Specialist

Swift 6.0+ development expert for iOS/macOS with SwiftUI, Combine, and Swift Concurrency.

Auto-Triggers: Swift files (.swift), iOS/macOS projects, Xcode workspaces

Quick Reference

Core Capabilities

• Swift 6.0: Typed throws, complete concurrency, data-race safety by default
• SwiftUI 6: @Observable macro, NavigationStack, modern declarative UI
• Combine: Reactive programming with publishers and subscribers
• Swift Concurrency: async/await, actors, TaskGroup, isolation
• XCTest: Unit testing, UI testing, async test support
• Swift Package Manager: Dependency management

Version Requirements

• Swift: 6.0+
• Xcode: 16.0+
• iOS: 17.0+ (recommended), minimum 15.0
• macOS: 14.0+ (recommended)

Project Setup

Package.swift Configuration:

// swift-tools-version: 6.0
import PackageDescription

let package = Package(
    name: "MyApp",
    platforms: [.iOS(.v17), .macOS(.v14)],
    products: [
        .library(name: "MyAppCore", targets: ["MyAppCore"])
    ],
    dependencies: [
        .package(url: "https://github.com/Alamofire/Alamofire.git", from: "5.9.0"),
        .package(url: "https://github.com/pointfreeco/swift-composable-architecture", from: "1.15.0")
    ],
    targets: [
        .target(name: "MyAppCore", dependencies: ["Alamofire"]),
        .testTarget(name: "MyAppCoreTests", dependencies: ["MyAppCore"])
    ]
)

Essential Patterns

Basic @Observable ViewModel:

import Observation

@Observable
@MainActor
final class ContentViewModel {
    private(set) var items: [Item] = []
    private(set) var isLoading = false
    
    func load() async {
        isLoading = true
        defer { isLoading = false }
        items = try? await api.fetchItems() ?? []
    }
}

Basic SwiftUI View:

struct ContentView: View {
    @State private var viewModel = ContentViewModel()
    
    var body: some View {
        NavigationStack {
            List(viewModel.items) { item in
                Text(item.title)
            }
            .task { await viewModel.load() }
            .refreshable { await viewModel.load() }
        }
    }
}

Basic Actor for Thread Safety:

actor DataCache {
    private var cache: [String: Data] = [:]
    
    func get(_ key: String) -> Data? { cache[key] }
    func set(_ key: String, data: Data) { cache[key] = data }
}

Module Index

Swift 6 Features

modules/swift6-features.md

• Typed throws for precise error handling
• Complete concurrency checking
• Data-race safety by default
• Sendable conformance requirements

SwiftUI Patterns

modules/swiftui-patterns.md

• @Observable macro and state management
• NavigationStack and navigation patterns
• View lifecycle and .task modifier
• Environment and dependency injection

Swift Concurrency

modules/concurrency.md

• async/await fundamentals
• Actor isolation and @MainActor
• TaskGroup for parallel execution
• Custom executors and structured concurrency

Combine Framework

modules/combine-reactive.md

• Publishers and Subscribers
• Operators and transformations
• async/await bridge patterns
• Integration with SwiftUI

Context7 Library Mappings

Core Swift

• /apple/swift - Swift language and standard library
• /apple/swift-evolution - Swift evolution proposals
• /apple/swift-package-manager - SwiftPM documentation
• /apple/swift-async-algorithms - Async sequence algorithms

Popular Libraries

• /Alamofire/Alamofire - HTTP networking
• /onevcat/Kingfisher - Image downloading and caching
• /realm/realm-swift - Mobile database
• /pointfreeco/swift-composable-architecture - TCA architecture
• /Quick/Quick - BDD testing framework
• /Quick/Nimble - Matcher framework

Testing Quick Start

Async Test with MainActor:

@MainActor
final class ViewModelTests: XCTestCase {
    func testLoadSuccess() async throws {
        let mockAPI = MockAPI()
        mockAPI.mockItems = [Item(id: "1", title: "Test")]
        let sut = ContentViewModel(api: mockAPI)
        
        await sut.load()
        
        XCTAssertEqual(sut.items.count, 1)
        XCTAssertFalse(sut.isLoading)
    }
}

Works Well With

• moai-lang-kotlin - Android counterpart for cross-platform projects
• moai-lang-flutter - Flutter/Dart for cross-platform mobile
• moai-domain-backend - API integration and backend communication
• moai-foundation-quality - iOS security best practices
• moai-workflow-testing - Xcode debugging and profiling

Resources

• reference.md - Architecture patterns, network layer, SwiftData
• examples.md - Production-ready code examples