swift-development

What this skill does

# 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

```bash
# 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

```bash
# 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

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

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

### Simulator Management

```bash
# 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

```bash
# 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

```bash
# 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

```bash
# 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:

1. **Swift Testing**: When you need details on `@Test`, `#expect`, `#require`, traits, or parameterized tests
2. **Swift Evolution**: When checking accepted proposals for new language features
3. **Framework Details**: When implementing features from Apple's open-source Swift packages
4. **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](references/swiftui-patterns.md) |
| Testing patterns | [references/testing-patterns.md](references/testing-patterns.md) |
| Swift 6 concurrency | [references/concurrency.md](references/concurrency.md) |
| Architecture patterns | [references/architecture.md](references/architecture.md) |
| Best practices | [references/best-practices.md](references/best-practices.md) |
| Swift Package Manager | [references/spm.md](references/spm.md) |
| xcodebuild commands | [references/xcodebuild.md](references/xcodebuild.md) |
| Simulator control | [references/simctl.md](references/simctl.md) |
| Code signing | [references/code-signing.md](references/code-signing.md) |
| CI/CD setup | [references/cicd.md](references/cicd.md) |
| Troubleshooting | [references/troubleshooting.md](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

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

# macOS
-destination 'platform=macOS'

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

---