Ios Swift Packages

// swift-tools-version: 5.9
import PackageDescription

let package = Package(
    // MARK: - Package Identity
    name: "DesignSystem",

    // MARK: - Default Localization
    defaultLocalization: "en",

    // MARK: - Supported Platforms
    platforms: [
        .iOS(.v17),
        .macOS(.v14),
        .watchOS(.v10),
        .tvOS(.v17),
        .visionOS(.v1)
    ],

    // MARK: - Products (What others can import)
    products: [
        // Main library
        .library(
            name: "DesignSystem",
            targets: ["DesignSystem"]
        ),
        // Dynamic library (for faster debug builds)
        .library(
            name: "DesignSystemDynamic",
            type: .dynamic,
            targets: ["DesignSystem"]
        ),
        // Plugin
        .plugin(
            name: "SwiftLintPlugin",
            targets: ["SwiftLintPlugin"]
        )
    ],

    // MARK: - Dependencies
    dependencies: [
        // Remote package (exact version)
        .package(url: "https://github.com/apple/swift-algorithms", exact: "1.2.0"),

        // Remote package (version range)
        .package(url: "https://github.com/pointfreeco/swift-composable-architecture", from: "1.5.0"),

        // Remote package (branch)
        .package(url: "https://github.com/user/repo", branch: "main"),

        // Remote package (commit)
        .package(url: "https://github.com/user/repo", revision: "abc123"),

        // Local package
        .package(path: "../Core"),
        .package(path: "../Networking"),

        // Conditional (for development)
        // .package(url: "...", from: "1.0.0"),
    ],

    // MARK: - Targets
    targets: [
        // Main target
        .target(
            name: "DesignSystem",
            dependencies: [
                // Product from package
                .product(name: "Algorithms", package: "swift-algorithms"),
                // Local target
                "DesignSystemCore",
                // Conditional dependency
                .target(name: "DesignSystemMacOS", condition: .when(platforms: [.macOS]))
            ],
            path: "Sources/DesignSystem",
            exclude: ["README.md"],
            resources: [
                // Process resources (localization, asset catalogs)
                .process("Resources"),
                // Copy as-is
                .copy("Fonts")
            ],
            swiftSettings: [
                .define("DEBUG", .when(configuration: .debug)),
                .enableUpcomingFeature("StrictConcurrency"),
                .enableExperimentalFeature("VariadicGenerics")
            ],
            linkerSettings: [
                .linkedFramework("CoreGraphics"),
                .linkedLibrary("sqlite3")
            ]
        ),

        // Core target (no dependencies)
        .target(
            name: "DesignSystemCore"
        ),

        // Platform-specific target
        .target(
            name: "DesignSystemMacOS",
            dependencies: ["DesignSystemCore"]
        ),

        // Test target
        .testTarget(
            name: "DesignSystemTests",
            dependencies: [
                "DesignSystem",
                .product(name: "CustomDump", package: "swift-custom-dump")
            ],
            resources: [
                .process("Fixtures")
            ]
        ),

        // Plugin target
        .plugin(
            name: "SwiftLintPlugin",
            capability: .buildTool(),
            dependencies: [
                .target(name: "SwiftLintBinary")
            ]
        ),

        // Binary target
        .binaryTarget(
            name: "SwiftLintBinary",
            url: "https://github.com/.../swiftlint.zip",
            checksum: "abc123..."
        )
    ],

    // MARK: - Swift Language Version
    swiftLanguageVersions: [.v5]
)

Common Patterns

Multi-Target Package

let package = Package(
    name: "Networking",
    platforms: [.iOS(.v17)],
    products: [
        .library(name: "Networking", targets: ["Networking"]),
        .library(name: "NetworkingMocks", targets: ["NetworkingMocks"])
    ],
    targets: [
        .target(name: "Networking"),
        .target(
            name: "NetworkingMocks",
            dependencies: ["Networking"]
        ),
        .testTarget(
            name: "NetworkingTests",
            dependencies: ["Networking", "NetworkingMocks"]
        )
    ]
)

Interface + Implementation Split

let package = Package(
    name: "Analytics",
    platforms: [.iOS(.v17)],
    products: [
        .library(name: "AnalyticsInterface", targets: ["AnalyticsInterface"]),
        .library(name: "Analytics", targets: ["Analytics"]),
        .library(name: "AnalyticsMock", targets: ["AnalyticsMock"])
    ],
    targets: [
        // Protocol only - no implementation
        .target(name: "AnalyticsInterface"),

        // Real implementation
        .target(
            name: "Analytics",
            dependencies: ["AnalyticsInterface"]
        ),

        // Mock for testing
        .target(
            name: "AnalyticsMock",
            dependencies: ["AnalyticsInterface"]
        ),

        .testTarget(
            name: "AnalyticsTests",
            dependencies: ["Analytics", "AnalyticsMock"]
        )
    ]
)

Resources in Packages

Adding Resources

.target(
    name: "DesignSystem",
    resources: [
        // Asset catalogs, localized strings, storyboards
        .process("Resources"),

        // Copy files exactly as-is
        .copy("Fonts/CustomFont.ttf"),

        // Specific file
        .process("config.json")
    ]
)

Accessing Resources

// Bundle for this module
let bundle = Bundle.module

// Load image
let image = UIImage(named: "icon", in: .module, with: nil)

// SwiftUI image
Image("icon", bundle: .module)

// Load data file
if let url = Bundle.module.url(forResource: "config", withExtension: "json") {
    let data = try Data(contentsOf: url)
}

// Localized strings
Text("welcome_message", bundle: .module)

Asset Catalog Setup

Sources/
└── DesignSystem/
    └── Resources/
        ├── Assets.xcassets/
        │   ├── Colors/
        │   │   └── Primary.colorset/
        │   └── Images/
        │       └── Logo.imageset/
        └── Localizable.xcstrings

Dependency Best Practices

Version Constraints