Swift Development Skill

Swift Development

Prerequisites

macOS with Xcode 15+ installed (Xcode 16+ for Swift 6)
Xcode Command Line Tools: xcode-select --install
Verify: xcodebuild -version and swift --version

Quick Start

New Swift Package

# Use the included script for full setup
./scripts/new_package.sh MyLibrary --type library --ios --macos

# Or manually
swift package init --type library --name MyLibrary

Build and Test

# SPM packages
swift build
swift test

# Xcode projects
xcodebuild -workspace App.xcworkspace -scheme App \
    -destination 'platform=iOS Simulator,name=iPhone 15' build

# Use included script for common options
./scripts/run_tests.sh --parallel --coverage

Format and Lint

# Use included script
./scripts/format_and_lint.sh Sources/

# Check mode (CI)
./scripts/format_and_lint.sh --check

Simulator Management

# Use included script
./scripts/simulator.sh list
./scripts/simulator.sh boot "iPhone 15"
./scripts/simulator.sh screenshot
./scripts/simulator.sh dark

Core Workflows

Building iOS Apps

# Debug build for simulator
xcodebuild -workspace App.xcworkspace -scheme App \
    -destination 'platform=iOS Simulator,name=iPhone 15' \
    build

# Release archive
xcodebuild archive \
    -workspace App.xcworkspace -scheme App \
    -archivePath ./build/App.xcarchive \
    -configuration Release

# Export IPA (use templates from assets/ExportOptions/)
xcodebuild -exportArchive \
    -archivePath ./build/App.xcarchive \
    -exportPath ./build/export \
    -exportOptionsPlist assets/ExportOptions/app-store.plist

Testing

# All tests
xcodebuild test -workspace App.xcworkspace -scheme App \
    -destination 'platform=iOS Simulator,name=iPhone 15'

# Specific test
xcodebuild test -only-testing:AppTests/MyTestClass/testMethod

# With coverage
xcodebuild test -enableCodeCoverage YES \
    -resultBundlePath ./TestResults.xcresult

App Installation

# Install on booted simulator
xcrun simctl install booted ./Build/Products/Debug-iphonesimulator/App.app

# Launch
xcrun simctl launch booted com.company.app

Official Documentation

Reference Links (for humans)

These are Apple's official documentation links for manual browsing:

| Resource | URL | |----------|-----| | Swift Documentation | https://developer.apple.com/documentation/swift | | SwiftUI | https://developer.apple.com/documentation/swiftui | | Swift Concurrency | https://developer.apple.com/documentation/swift/concurrency | | Swift Testing | https://developer.apple.com/documentation/testing |

Note: Apple's documentation sites are JavaScript SPAs and cannot be fetched programmatically with WebFetch.

WebFetch-Compatible Sources

Use these GitHub-based sources for live documentation fetching:

| Resource | URL | |----------|-----| | Swift Testing | https://github.com/apple/swift-testing | | Swift Evolution Proposals | https://github.com/apple/swift-evolution/tree/main/proposals | | Swift Compiler Docs | https://github.com/apple/swift/tree/main/docs | | Swift Standard Library | https://github.com/apple/swift/tree/main/stdlib | | Swift Async Algorithms | https://github.com/apple/swift-async-algorithms | | Swift Collections | https://github.com/apple/swift-collections |

When to Fetch Documentation

Use WebFetch to retrieve documentation from GitHub in these situations:

Swift Testing: When you need details on @Test, #expect, #require, traits, or parameterized tests
Swift Evolution: When checking accepted proposals for new language features
Framework Details: When implementing features from Apple's open-source Swift packages
Uncertainty: When you're unsure about current API patterns or best practices

How to fetch: Use WebFetch with GitHub URLs:

README: https://github.com/apple/swift-testing
Raw markdown: https://raw.githubusercontent.com/apple/swift-testing/main/README.md
Specific docs: https://github.com/apple/swift-evolution/blob/main/proposals/0409-access-level-on-imports.md

Example prompt for WebFetch: "Extract the main features, macros, and usage examples from this documentation"

Reference Files

Detailed documentation for specific topics:

| Topic | File | |-------|------| | SwiftUI patterns | references/swiftui-patterns.md | | Testing patterns | references/testing-patterns.md | | Swift 6 concurrency | references/concurrency.md | | Architecture patterns | references/architecture.md | | Best practices | references/best-practices.md | | Swift Package Manager | references/spm.md | | xcodebuild commands | references/xcodebuild.md | | Simulator control | references/simctl.md | | Code signing | references/code-signing.md | | CI/CD setup | references/cicd.md | | Troubleshooting | references/troubleshooting.md |

Included Scripts

| Script | Purpose | |--------|---------| | scripts/new_package.sh | Create new Swift package with config files | | scripts/run_tests.sh | Run tests with common options | | scripts/format_and_lint.sh | Format and lint Swift code | | scripts/simulator.sh | Quick simulator management |

Asset Templates

| Asset | Purpose | |-------|---------| | assets/Package.swift.template | Swift package template | | assets/.swiftformat | SwiftFormat configuration | | assets/.swiftlint.yml | SwiftLint configuration | | assets/ExportOptions/ | Archive export plist templates |

Quick Reference

Essential Commands

| Task | Command | |------|---------| | Build package | swift build | | Build release | swift build -c release | | Run tests | swift test | | Update deps | swift package update | | List simulators | xcrun simctl list devices | | Boot simulator | xcrun simctl boot "iPhone 15" | | Install app | xcrun simctl install booted ./App.app | | Format code | swiftformat . | | Lint code | swiftlint |

Common Destinations

# iOS Simulator
-destination 'platform=iOS Simulator,name=iPhone 15'

# macOS
-destination 'platform=macOS'

# Generic iOS (for archives)
-destination 'generic/platform=iOS'

Agent Skills: Swift Development

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