Layout, products & build/test/run

Overview

Folder layout

let tree = """
MyPkg/
├─ Package.swift
├─ Sources/
│  ├─ MyLib/            // library target sources
│  │  └─ MyLib.swift
│  └─ MyApp/            // executable target sources (main.swift)
│     └─ main.swift
└─ Tests/
   ├─ MyLibTests/
   │  └─ MyLibTests.swift
   └─ MyAppTests/
      └─ MyAppTests.swift
"""
print(tree)

Products & targets

let manifest = """
// Package.swift (illustrative)
import PackageDescription
let package = Package(
  name: "MyPkg",
  products: [
    .library(name: "MyLib", targets: ["MyLib"]),
    .executable(name: "MyApp", targets: ["MyApp"])
  ],
  targets: [
    .target(name: "MyLib"),
    .executableTarget(name: "MyApp", dependencies: ["MyLib"]),
    .testTarget(name: "MyLibTests", dependencies: ["MyLib"])
  ]
)
"""
print(manifest)

Library vs executable

// Library code (Sources/MyLib/MyLib.swift)
public struct Greeter {
    public init() {}
    public func hello(_ name: String) -> String { "Hello, \\(name)" }
}

// Executable entry (Sources/MyApp/main.swift)
let g = Greeter()
print(g.hello("World"))

CLI basics

let cmds = """
# Build (debug by default)
swift build

# Run an executable product
swift run MyApp

# Execute tests (XCTest)
swift test

# Release build (optimized)
swift build -c release
"""
print(cmds)

Artifacts & tips

let notes = """
Artifacts live under .build/:
  • debug/ and release/ contain compiled products
  • x86_64-apple-macosx / arm64-apple-* vary by platform/arch
Tips:
  • Keep one target per responsibility
  • Name products simply; match target folders
  • Put tests in Tests/<TargetName>Tests
"""
print(notes)

Run tests

Recap