로컬 패키지와 기능 모듈

// Without modules: one giant target recompiles everything
// With modules: changes to FeatureA only recompile FeatureA

mkdir Features/UserProfile
cd Features/UserProfile
swift package init --name UserProfile --type library

// In Xcode:
// File → Add Package Dependencies → Add Local...
// Select the package directory

.package(path: "../Features/UserProfile"),
// In the target:
.product(name: "UserProfile", package: "UserProfile")

// UserProfile/Sources/UserProfile/ProfileView.swift
public struct ProfileView: View {
  public init() {}
  public var body: some View { Text("Profile") }
}

// Only visible within UserProfile module:
final class ProfileCache { ... }
struct ProfileMapper { ... }

// UserProfile/
// ├── Sources/UserProfile/
// │   ├── Domain/         (entities, use cases, protocols)
// │   ├── Data/           (repositories)
// │   └── Presentation/   (views, view models)
// └── Tests/UserProfileTests/

// CoreNetwork package
// CoreDesign package
// Both imported by FeatureA and FeatureB

// GOOD:
// FeatureA → CoreNetwork
// FeatureB → CoreNetwork
// BAD:
// FeatureA → FeatureB  (tight coupling)

// Change in UserProfile → only UserProfile recompiles
// App target links the new binary → fast incremental build

// Run all tests:
swift test --package-path Features/UserProfile
// Or let Xcode run them as part of the main test plan