swift-ios

name	swift-ios
description	Développement iOS natif avec Swift — SwiftUI, UIKit, Xcode, frameworks Apple, performance, déploiement

Skill: Développement iOS/Swift

Vue d'ensemble

Développement d'applications iOS natives avec Swift, couvrant SwiftUI et UIKit, les frameworks système Apple, l'optimisation des performances, et le déploiement sur l'App Store.

1. Swift — Langage et Fondamentaux

1.1 Syntaxe Moderne

// Protocol-oriented programming
protocol Repository {
    associatedtype T
    func fetch(id: String) async throws -> T
    func save(_ item: T) async throws
}

// Value semantics avec structs
struct User: Identifiable, Codable {
    let id: UUID
    var name: String
    var email: String
    var createdAt: Date
}

// Result builders pour DSL
@resultBuilder
struct ViewBuilder {
    static func buildBlock<Content: View>(_ content: Content) -> Content
}

1.2 Concurrency (Swift 5.5+)

• async/await — async functions, structured concurrency
• Task & TaskGroup — parallélisme structuré
• Actors — isolation des données mutables, @MainActor
• AsyncSequence — AsyncStream, AsyncPublisher
• Continuations — withCheckedContinuation, withUnsafeContinuation

1.3 Patterns Avancés

• Property Wrappers — @Published, @State, @Binding, @Environment, @AppStorage
• Codable — custom encoding/decoding, JSONEncoder.KeyEncodingStrategy
• Macros (Swift 5.9+) — @Observable, #Predicate, macros custom
• Generics — associated types, opaque types (some), any existential

2. SwiftUI

2.1 Architecture SwiftUI

@Observable
final class AppViewModel {
    var users: [User] = []
    var isLoading = false
    
    @MainActor
    func loadUsers() async {
        isLoading = true
        defer { isLoading = false }
        users = try await api.fetchUsers()
    }
}

struct UserListView: View {
    @State private var viewModel = AppViewModel()
    
    var body: some View {
        List(viewModel.users) { user in
            UserRow(user: user)
        }
        .task { await viewModel.loadUsers() }
        .refreshable { await viewModel.loadUsers() }
        .overlay {
            if viewModel.isLoading { ProgressView() }
        }
    }
}

2.2 Layout & Navigation

• NavigationStack (iOS 16+) — programme driven navigation, .navigationDestination
• NavigationSplitView — iPad/macOS multi-column
• LazyVStack/LazyHStack — lazy loading, performance
• Grid/GridRow — layouts en grille (iOS 16+)
• AnyLayout — layout adaptatif (HStack ↔ VStack)
• ContainerRelativeFrame — iOS 17+ sizing

2.3 Data Flow

Pattern	Usage	Scope
@State	Valeurs locales	View
@Binding	Two-way binding	Parent → Child
@Observable (iOS 17+)	Observable object	ViewModel
@Environment	Valeurs partagées	App tree
@AppStorage	UserDefaults	Persistence
SwiftData / CoreData	Persistance	Model layer

2.4 Animations

• .withAnimation — animation explicite
• .animation — value-based animation
• matchedGeometryEffect — transitions fluides
• PhaseAnimator (iOS 17+) — animations séquencées
• KeyframeAnimator (iOS 17+) — animations keyframe
• Custom transitions — AnyTransition.asymmetric

3. UIKit (Maintenance & Legacy)

3.1 UIKit Interop (UIViewRepresentable)

struct MapView: UIViewRepresentable {
    let coordinate: CLLocationCoordinate2D
    
    func makeUIView(context: Context) -> MKMapView {
        MKMapView()
    }
    
    func updateUIView(_ uiView: MKMapView, context: Context) {
        uiView.setRegion(MKCoordinateRegion(center: coordinate, span: .init(latitudeDelta: 0.05, longitudeDelta: 0.05)), animated: true)
    }
}

3.2 UIKit Patterns

• UICollectionView — CompositionalLayout, diffable data sources
• UIViewController — lifecycle, containment, UIViewControllerTransitioningDelegate
• Auto Layout — NSLayoutConstraint, UIStackView
• UIScrollView — content insets, refresh control, keyboard avoidance
• UITableViewController — self-sizing cells, prefetching

4. Frameworks Système

4.1 Networking

• URLSession — async/await, URLSessionConfiguration.background, caching
• URLProtocol — intercepteur réseau custom
• WebSocket — URLSessionWebSocketTask
• Alamofire / Moya — libraries tierces (quand URLSession ne suffit pas)

4.2 Persistance

• SwiftData (iOS 17+) — #Model, @Query, @ModelActor
• CoreData — NSPersistentContainer, NSManagedObjectContext, CloudKit sync
• GRDB — SQLite Swift avec query builder
• UserDefaults / @AppStorage — preferences simples
• Keychain — SecItemAdd, SecItemCopyMatching
• FileManager — documents directory, cache, temp

4.3 Localisation

• String Catalogs (Xcode 15+) — .xcstrings
• LocalizedStringResource — type-safe localization (iOS 16+)
• Formatters — DateFormatter, NumberFormatter, ListFormatter
• RTL — .leading/.trailing au lieu de .left/.right

4.4 Frameworks Apple

Framework	Usage
CoreLocation	GPS, geofencing, CLMonitor
MapKit	Cartes, annotations, routage
CloudKit	Sync iCloud, CKContainer
NotificationCenter	Notifications locales/push
CoreBluetooth	BLE central/peripheral
HealthKit	Santé, HKWorkout, HKSample
AVFoundation	Audio, vidéo, capture
Vision	Détection faciale, OCR, tracking
CoreML	ML on-device, .mlpackage
WidgetKit	Widgets, Live Activities
StoreKit	In-app purchases, subscriptions
WeatherKit	Données météo (iOS 16+)
Accelerate	DSP, vectorisation, BNNS
Metal	GPU compute, shaders

5. Xcode & Tooling

5.1 Configuration Projet

# xcodebuild ligne de commande
xcodebuild -project App.xcodeproj -scheme App -destination 'platform=iOS Simulator,name=iPhone 16 Pro' test

# Build avec code signing
xcodebuild -workspace App.xcworkspace -scheme App archive -archivePath build/App.xcarchive

# Export IPA
xcodebuild -exportArchive -archivePath build/App.xcarchive -exportPath build/ -exportOptionsPlist ExportOptions.plist

5.2 Swift Package Manager

// Package.swift
dependencies: [
    .package(url: "https://github.com/pointfreeco/swift-composable-architecture", from: "1.10.0"),
    .package(url: "https://github.com/onevcat/Kingfisher", from: "8.0.0")
]

5.3 Build Settings

• Swift Compiler — strict concurrency checking, whole module optimization
• Asset Catalogs — .xcassets, app icons, colors, symbols
• Info.plist — permissions (NSCameraUsageDescription, etc.)
• Entitlements — capabilities, App Groups, keychain sharing
• Build Phases — Run Script, SwiftGen, Sourcery, SwiftLint

6. Performance & Optimisation

6.1 Memory

• Leak detection — Xcode Memory Graph Debugger, Instruments (Leaks, Allocations)
• Value semantics — préférer structs aux classes
• Lazy loading — images, données, vues
• COW (Copy-on-Write) — éviter les copies inutiles
• Weak references — [weak self] dans les closures

6.2 UI Performance

• Instruments — Time Profiler, Core Animation, System Trace
• SwiftUI diffing — EquatableView, @ViewBuilder lazy
• Image caching — Kingfisher/Nuke, URLCache
• Precomputed layout — CGSize caching, GeometryReader minimal
• Background tasks — BGTaskScheduler pour les tâches différées

6.3 App Size

• App Thinning — Slicing, Bitcode, On-Demand Resources
• Asset compression — ImageOptim, SVG en SF Symbols
• Dead code stripping — -dead_strip, Swift compiler optimizations
• XCFramework — universal binaries

7. Tests

7.1 XCTest

final class UserViewModelTests: XCTestCase {
    var sut: UserViewModel!
    var mockAPI: MockAPIClient!
    
    override func setUp() {
        mockAPI = MockAPIClient()
        sut = UserViewModel(api: mockAPI)
    }
    
    func testLoadUsersSuccess() async throws {
        mockAPI.stub(.fetchUsers, return: [.mock])
        await sut.loadUsers()
        XCTAssertEqual(sut.users.count, 1)
        XCTAssertFalse(sut.isLoading)
    }
}

7.2 UI Tests (XCUITest)

func testLoginFlow() {
    let app = XCUIApplication()
    app.launch()
    
    let emailField = app.textFields["email"]
    emailField.tap()
    emailField.typeText("[e-mail]")
    
    app.buttons["Connexion"].tap()
    XCTAssertTrue(app.staticTexts["Dashboard"].waitForExistence(timeout: 5))
}

7.3 Snapshot Testing

• SnapshotTesting (Point-Free) — assertSnapshot(of: view, as: .image)
• SwiftSnapshotTesting — layout, text, localisation variants

8. Déploiement & CI/CD

8.1 Fastlane

lane :deploy do
  match(type: "appstore")
  build_app(
    scheme: "App",
    export_method: "app-store"
  )
  upload_to_app_store(
    skip_metadata: true,
    skip_screenshots: true
  )
end

8.2 GitHub Actions

- name: Build & Test
  run: |
    xcodebuild test \
      -scheme App \
      -destination 'platform=iOS Simulator,name=iPhone 16 Pro' \
      -resultBundlePath TestResults.xcresult

8.3 Code Signing

• Automatic signing — Xcode managed profiles
• Match (Fastlane) — encrypted profiles in git
• Manual — Apple Developer Portal, security import

9. Pièges Courants

• MainActor strict — oublier @MainActor sur les mises à jour UI → crash
• Reference cycles — closures sans [weak self] → leak
• SwiftUI identity — ForEach sans .id → animations cassées
• Background tasks timeout — BGTaskScheduler 30s max
• Push notifications — sandbox vs production APNs
• App Store review — guideline 4.2 (minimum functionality), 2.1 (app completeness)
• iOS 17+ APIs — availability checks avec #available(iOS 17, *)