iOS Development

Comprehensive iOS app development skill for iOS 17+ with SwiftUI, MVVM architecture, and modern Swift practices.

Overview

Target Platform: iOS 17+ / Swift 5.9+

Core Technologies:

• UI Framework: SwiftUI (primary), UIKit (when needed)
• Architecture: MVVM with Repository pattern
• Data: SwiftData (recommended), Core Data
• Networking: Alamofire / Moya
• Testing: XCTest

Quick Start

New Project Setup

To create a new iOS project:

1. Open Xcode and select "Create New Project"
2. Choose "App" template with SwiftUI interface
3. Set minimum deployment target to iOS 17.0
4. Enable Swift strict concurrency checking in Build Settings

Existing Project Analysis

To analyze an existing project structure:

bash scripts/project-analyzer.sh /path/to/project

SwiftUI Essentials

State Management (iOS 17+)

Use @Observable macro for state management:

@Observable
class ViewModel {
    var items: [Item] = []
    var isLoading = false
}

struct ContentView: View {
    @State private var viewModel = ViewModel()

    var body: some View {
        List(viewModel.items) { item in
            Text(item.name)
        }
    }
}

Navigation

Use NavigationStack with type-safe navigation:

@Observable
class Router {
    var path = NavigationPath()

    func navigate(to destination: Destination) {
        path.append(destination)
    }
}

struct ContentView: View {
    @State private var router = Router()

    var body: some View {
        NavigationStack(path: $router.path) {
            // content
        }
        .environment(router)
    }
}

For detailed SwiftUI patterns, see references/swiftui.md.

MVVM Architecture

Layer Structure

Presentation Layer
├── View (SwiftUI Views)
└── ViewModel (@Observable classes)

Domain Layer
├── Model (Data structures)
└── UseCase (Business logic)

Data Layer
├── Repository (Data access abstraction)
└── DataSource (API, Database)

ViewModel Design

@Observable
class UserListViewModel {
    private(set) var users: [User] = []
    private(set) var isLoading = false
    private(set) var error: Error?

    private let repository: UserRepositoryProtocol

    init(repository: UserRepositoryProtocol) {
        self.repository = repository
    }

    @MainActor
    func loadUsers() async {
        isLoading = true
        defer { isLoading = false }

        do {
            users = try await repository.fetchUsers()
        } catch {
            self.error = error
        }
    }
}

For detailed MVVM patterns, see references/mvvm.md.

Data Persistence

SwiftData (Recommended for iOS 17+)

@Model
class Item {
    var name: String
    var createdAt: Date

    init(name: String) {
        self.name = name
        self.createdAt = .now
    }
}

// In App
@main
struct MyApp: App {
    var body: some Scene {
        WindowGroup {
            ContentView()
        }
        .modelContainer(for: Item.self)
    }
}

For detailed data layer patterns, see references/data-layer.md.

Networking

Moya Setup

enum UserAPI {
    case getUsers
    case getUser(id: Int)
    case createUser(name: String, email: String)
}

extension UserAPI: TargetType {
    var baseURL: URL { URL(string: "https://api.example.com")! }

    var path: String {
        switch self {
        case .getUsers: return "/users"
        case .getUser(let id): return "/users/\(id)"
        case .createUser: return "/users"
        }
    }

    var method: Moya.Method {
        switch self {
        case .getUsers, .getUser: return .get
        case .createUser: return .post
        }
    }
    // ... other requirements
}

For detailed networking patterns, see references/networking.md.

Testing Basics

ViewModel Testing

@MainActor
final class UserListViewModelTests: XCTestCase {
    func test_loadUsers_success() async {
        // Arrange
        let mockRepository = MockUserRepository()
        mockRepository.usersToReturn = [User(id: 1, name: "Test")]
        let viewModel = UserListViewModel(repository: mockRepository)

        // Act
        await viewModel.loadUsers()

        // Assert
        XCTAssertEqual(viewModel.users.count, 1)
        XCTAssertFalse(viewModel.isLoading)
    }
}

For detailed testing patterns, see references/testing.md.

Accessibility

Essential Practices

struct ItemRow: View {
    let item: Item

    var body: some View {
        HStack {
            Image(systemName: item.icon)
                .accessibilityHidden(true)

            Text(item.name)
        }
        .accessibilityElement(children: .combine)
        .accessibilityLabel(item.name)
        .accessibilityHint("Double tap to view details")
    }
}

Key accessibility requirements:

• Add accessibility labels to all interactive elements
• Support Dynamic Type with .dynamicTypeSize() modifier
• Test with VoiceOver enabled
• Ensure sufficient color contrast

For detailed accessibility guidelines, see references/accessibility.md.

CI/CD

Xcode Cloud

To set up Xcode Cloud:

1. Navigate to Product > Xcode Cloud > Create Workflow
2. Configure build triggers (push, PR, tag)
3. Add test action for unit tests
4. Configure archive and distribution

fastlane

# Fastfile
default_platform(:ios)

platform :ios do
  lane :test do
    run_tests(scheme: "MyApp")
  end

  lane :beta do
    build_app(scheme: "MyApp")
    upload_to_testflight
  end
end

For detailed CI/CD setup, see references/cicd.md.

Code Quality Checklist

Before submitting code, verify:

• All public APIs have documentation comments
• ViewModels use @MainActor for UI updates
• Network calls handle errors appropriately
• Accessibility labels are added to interactive elements
• Unit tests cover critical business logic
• No force unwrapping (!) without safety checks
• Memory management: no retain cycles in closures

Additional Resources

Reference Files

• references/swiftui.md - SwiftUI patterns and iOS 17+ features
• references/mvvm.md - MVVM architecture details
• references/data-layer.md - SwiftData and Core Data
• references/networking.md - Alamofire / Moya patterns
• references/testing.md - XCTest and mocking
• references/accessibility.md - Accessibility implementation
• references/cicd.md - CI/CD configuration

Example Files

• examples/swiftui-components.swift - SwiftUI component examples
• examples/mvvm-pattern.swift - Complete MVVM implementation
• examples/moya-networking.swift - Moya networking setup
• examples/unit-test-example.swift - Unit test examples

Utility Scripts

• scripts/project-analyzer.sh - Analyze iOS project structure