ios-developer

name	ios_developer
description	Comprehensive iOS development guidance covering SwiftUI, Swift Concurrency, Core Data, and Swift Testing

iOS Developer

You are an iOS development expert. This skill aggregates best practices from specialized agent skills for comprehensive iOS app development.

When to Use

• Building iOS/macOS/visionOS applications
• Working with SwiftUI views and state management
• Implementing Swift Concurrency patterns
• Using Core Data for persistence
• Writing tests with Swift Testing framework
• Migrating to modern Swift patterns

Decision Tree

Need	Reference
SwiftUI views, state, modern APIs	→ swiftui.md
What's new in SwiftUI by iOS version	→ whats-new-swiftui/
What's new in Swift by version	→ whats-new-swift/
async/await, actors, Sendable	→ swift-concurrency.md
Core Data persistence, threading	→ core-data.md
Swift Testing, migration from XCTest	→ swift-testing.md
General Swift patterns and practices	→ swift.md

Core Principles

1. Use Modern APIs - Prefer @Observable over ObservableObject, NavigationStack over NavigationView
2. Actor Isolation - Understand @MainActor and custom actors for thread safety
3. Structured Concurrency - Use task groups over Task.detached when possible
4. Context Safety - Never pass NSManagedObject across Core Data contexts
5. Test with Swift Testing - Prefer #expect and #require over XCTest assertions

Quick Reference

SwiftUI State Management

@Observable
@MainActor
final class ViewModel {
    var items: [Item] = []

    func load() async {
        items = await fetchItems()
    }
}

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

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

Swift Concurrency

// Structured concurrency with task group
func fetchAllData() async throws -> [Data] {
    try await withThrowingTaskGroup(of: Data.self) { group in
        for url in urls {
            group.addTask { try await fetch(url) }
        }
        return try await group.reduce(into: []) { $0.append($1) }
    }
}

// Actor for shared state
actor DataStore {
    private var cache: [String: Data] = [:]

    func get(_ key: String) -> Data? { cache[key] }
    func set(_ key: String, _ value: Data) { cache[key] = value }
}

Core Data Background Context

// Safe background processing
func importData(_ items: [ImportItem]) async throws {
    let context = container.newBackgroundContext()
    try await context.perform {
        for item in items {
            let entity = Entity(context: context)
            entity.configure(from: item)
        }
        try context.save()
    }
}

// Pass IDs, not objects
let objectID = managedObject.objectID
Task.detached {
    let context = container.newBackgroundContext()
    let object = try context.existingObject(with: objectID)
    // Work with object safely
}

Swift Testing

import Testing

@Test("User login succeeds with valid credentials")
func loginSuccess() async throws {
    let auth = AuthService()
    let user = try #require(await auth.login(email: "[e-mail]", password: "valid"))
    #expect(user.isAuthenticated)
}

@Test(arguments: ["admin", "user", "guest"])
func rolePermissions(role: String) {
    let permissions = Permissions(role: role)
    #expect(permissions.canRead)
}

References

• swiftui.md - SwiftUI best practices, state management, modern APIs
• whats-new-swiftui/ - SwiftUI features by iOS version (14, 15, 16, 17, 18, 26)
• whats-new-swift/ - Swift language features by version (5.1-6.1)
• swift-concurrency.md - async/await, actors, Sendable, Swift 6 migration
• core-data.md - Core Data patterns, threading, migrations
• swift-testing.md - Swift Testing framework, XCTest migration
• swift.md - General Swift development patterns

External Resources

For more reference, use these open-source agent skills and documentation services:

AvdLee Skills

• SwiftUI-Agent-Skill - SwiftUI best practices
• Swift-Concurrency-Agent-Skill - Swift Concurrency patterns
• Core-Data-Agent-Skill - Core Data guidance
• Swift-Testing-Agent-Skill - Swift Testing framework

Dimillian Skills

• Skills Repository - iOS development skills collection
  • SwiftUI Liquid Glass - iOS 26+ Liquid Glass API
  • SwiftUI UI Patterns - View composition and state
  • SwiftUI View Refactor - Code consistency patterns
  • SwiftUI Performance Audit - Performance optimization
  • Swift Concurrency Expert - Swift 6.2+ concurrency
  • iOS Debugger Agent - Build and debug workflows
  • App Store Changelog - Release notes generation

twostraws Skills

• SwiftUI-Agent-Skill - SwiftUI best practices and patterns

Apple Documentation

• sosumi.ai - AI-readable Apple Developer documentation
  • Replace developer.apple.com with sosumi.ai in URLs (e.g., https://sosumi.ai/documentation/swiftui/view)
  • MCP server at https://sosumi.ai/mcp with tools: searchAppleDocumentation, fetchAppleDocumentation, fetchAppleVideoTranscript