Added some more cases to the File enumeration in the library target.

Library/Resources/Files/Sources/App/App

@@ -0,0 +1,20 @@
+import AppLibrary
+import ArgumentParser
+
+@main
+struct App: AsyncParsableCommand {
+    
+    // MARK: Properties
+
+    @OptionGroup var options: Options
+    
+    // MARK: Functions
+
+    mutating func run() async throws {
+        let builder = AppBuilder(name: "App")
+        let app = try await builder(options)
+
+        try await app.runService()
+    }
+
+}

Library/Resources/Files/Sources/App/AppOptions

@@ -0,0 +1,20 @@
+import AppLibrary
+import ArgumentParser
+import Logging
+
+extension App {
+    struct Options: AppArguments, ParsableArguments {
+        
+        // MARK: Properties
+        
+        @Option(name: .shortAndLong)
+        var hostname: String = "127.0.0.1"
+
+        @Option(name: .shortAndLong)
+        var port: Int = 8080
+
+        @Option(name: .shortAndLong)
+        var logLevel: Logger.Level?
+        
+    }
+}

Library/Resources/Files/Sources/Library/AppArguments

@@ -0,0 +1,11 @@
+import Logging
+
+public protocol AppArguments {
+    
+    // MARK: Properties
+    
+    var hostname: String { get }
+    var logLevel: Logger.Level? { get }
+    var port: Int { get }
+    
+}

Library/Resources/Files/Sources/Library/AppBuilder

@@ -0,0 +1,69 @@
+import Hummingbird
+import Logging
+
+public struct AppBuilder {
+
+    // MARK: Properties
+    
+    private let environment: Environment
+    private let name: String
+    
+    // MARK: Initialisers
+    
+    public init(name: String) {
+        self.environment = Environment()
+        self.name = name
+    }
+    
+    // MARK: Functions
+    
+    public func callAsFunction(
+        _ arguments: some AppArguments
+    ) async throws -> some ApplicationProtocol {
+        let logger = {
+            var logger = Logger(label: name)
+            
+            logger.logLevel = arguments.logLevel
+                ?? environment.logLevel.flatMap { Logger.Level(rawValue: $0) ?? .info }
+                ?? .info
+
+            return logger
+        }()
+        
+        let router = router(logger: logger)
+
+        return Application(
+            router: router,
+            configuration: .init(
+                address: .hostname(arguments.hostname, port: arguments.port),
+                serverName: name
+            ),
+            logger: logger
+        )
+    }
+
+}
+
+// MARK: - Helpers
+
+private extension AppBuilder {
+
+    // MARK: Type aliases
+    
+    typealias AppRequestContext = BasicRequestContext
+
+    // MARK: Functions
+    
+    func router(logger: Logger) -> Router<AppRequestContext> {
+        let router = Router()
+
+        router.add(middleware: LogRequestsMiddleware(logger.logLevel))
+        
+        router.get("/") { _,_ in
+            ""
+        }
+
+        return router
+    }
+
+}

Library/Resources/Files/Sources/Library/Environment

@@ -0,0 +1,11 @@
+import Hummingbird
+
+extension Environment {
+    
+    // MARK: Computed
+    
+    public var logLevel: String? {
+        self.get("LOG_LEVEL")
+    }
+    
+}

Library/Resources/Files/Sources/Library/LoggerLevel

@@ -0,0 +1,9 @@
+import ArgumentParser
+import Logging
+
+/// Extend `Logger.Level` so it can be used as an argument
+#if hasFeature(RetroactiveAttribute)
+extension Logger.Level: @retroactive ExpressibleByArgument {}
+#else
+extension Logger.Level: ExpressibleByArgument {}
+#endif

Library/Resources/Files/Sources/Package

@@ -5,7 +5,7 @@ import PackageDescription
 let package = Package(
     name: "App",
     platforms: [
-        .macOS(.v10_15)
+        .macOS(.v14)
     ],
     products: [
         .executable(name: "App", targets: ["App"]),

Library/Resources/Files/Sources/Test/AppTests

@@ -0,0 +1,33 @@
+import AppLibrary
+import Hummingbird
+import HummingbirdTesting
+import Testing
+
+struct AppTests {
+
+    // MARK: Properties
+
+    private let arguments = TestArguments()
+    private let builder = AppBuilder(name: "App")
+
+    // MARK: Route tests
+    
+    @Test(arguments: ["/"])
+    func routes(_ uri: String) async throws {
+        let app = try await builder(arguments)
+
+        try await app.test(.router) { client in
+            try await client.execute(uri: uri, method: .get) { response in
+                #expect(response.status == .ok)
+                #expect(response.body == .empty)
+            }
+        }
+    }
+
+}
+
+// MARK: ByteBuffer+Constants
+
+private extension ByteBuffer {
+    static let empty = ByteBuffer(string: "")
+}

Library/Resources/Files/Sources/Test/TestArguments

@@ -0,0 +1,12 @@
+import AppLibrary
+import Logging
+
+struct TestArguments: AppArguments {
+
+    // MARK: Properties
+
+    let hostname = "127.0.0.1"
+    let port = 0
+    let logLevel: Logger.Level? = .trace
+
+}

Library/Sources/Internal/Enumerations/File.swift

@@ -1,10 +1,19 @@
 enum File: String {
+    case app = "App"
+    case appArguments = "AppArguments"
+    case appBuilder = "AppBuilder"
+    case appOptions = "AppOptions"
+    case appTests = "AppTests"
     case dockerFile = "DockerFile"
     case dockerIgnore = "DockerIgnore"
+    case environment = "Environment"
     case gitIgnore = "GitIgnore"
     case license = "License"
+    case loggerLevel = "LoggerLevel"
     case package = "Package"
     case readme = "Readme"
+    case testArguments = "TestArguments"
+    
 }
 
 // MARK: - Properties
@@ -15,30 +24,46 @@ extension File {
 
     var fileName: String {
         switch self {
+        case .app: "App.swift"
+        case .appArguments: "AppArguments.swift"
+        case .appBuilder: "AppBuilder.swift"
+        case .appOptions: "AppOptions.swift"
+        case .appTests: "AppTests.swift"
         case .dockerFile: "Dockerfile"
         case .dockerIgnore: ".dockerignore"
+        case .environment: "Environment+Properties.swift"
         case .gitIgnore: ".gitignore"
         case .license: "LICENSE"
+        case .loggerLevel: "LoggerLevel+Conformances.swift"
         case .readme: "README.md"
         case .package: "Package.swift"
+        case .testArguments: "TestArguments.swift"
         }
     }
     
     var filePath: String {
-        switch self {
+        folder.path + fileName
-        default: folder.path + fileName
-        }
     }
     
     var folder: Folder {
         switch self {
+        case .app, .appOptions: .app
+        case .appArguments, .appBuilder: .libraryPublic
+        case .appTests: .testCasesPublic
+        case .environment, .loggerLevel: .libraryInternal
+        case .testArguments: .testHelpers
         default: .root
         }
     }
     
     var resourcePath: String {
-        switch self {
+        let basePath = "Resources/Files/Sources"
-        default: "Resources/Files/Sources"
+        
+        return switch self {
+        case .app, .appOptions: "\(basePath)/App"
+        case .appArguments, .appBuilder, .environment, .loggerLevel: "\(basePath)/Library"
+        case .appTests, .testArguments: "\(basePath)/Test"
+        default: basePath
         }
     }
     

Library/Sources/Internal/Enumerations/Folder.swift

@@ -16,13 +16,13 @@ extension Folder {
     
     var path: String {
         switch self {
-        case .app: "App/Sources"
+        case .app: "App/Sources/"
-        case .libraryPublic: "Library/Sources/Public"
+        case .libraryPublic: "Library/Sources/Public/"
-        case .libraryInternal: "Library/Sources/Internal"
+        case .libraryInternal: "Library/Sources/Internal/"
         case .root: ""
-        case .testCasesPublic: "Test/Sources/Cases/Public"
+        case .testCasesPublic: "Test/Sources/Cases/Public/"
-        case .testCasesInternal: "Test/Sources/Cases/Internal"
+        case .testCasesInternal: "Test/Sources/Cases/Internal/"
-        case .testHelpers: "Test/Sources/Helpers"
+        case .testHelpers: "Test/Sources/Helpers/"
         }
     }
     

Test/Sources/Cases/Internal/Enumerations/FileTests.swift

@@ -53,40 +53,72 @@ struct FileTests {
 private extension FileTests {
     enum Expectation {
         static let fileNames: [String] = [
+            "App.swift",
+            "AppArguments.swift",
+            "AppBuilder.swift",
+            "AppOptions.swift",
+            "AppTests.swift",
             "Dockerfile",
             ".dockerignore",
+            "Environment+Properties.swift",
             ".gitignore",
             "LICENSE",
+            "LoggerLevel+Conformances.swift",
             "Package.swift",
-            "README.md"
+            "README.md",
+            "TestArguments.swift"
         ]
 
         static let filePaths: [String] = [
+            "App/Sources/App.swift",
+            "Library/Sources/Public/AppArguments.swift",
+            "Library/Sources/Public/AppBuilder.swift",
+            "App/Sources/AppOptions.swift",
+            "Test/Sources/Cases/Public/AppTests.swift",
             "Dockerfile",
             ".dockerignore",
+            "Library/Sources/Internal/Environment+Properties.swift",
             ".gitignore",
             "LICENSE",
+            "Library/Sources/Internal/LoggerLevel+Conformances.swift",
             "Package.swift",
-            "README.md"
+            "README.md",
+            "Test/Sources/Helpers/TestArguments.swift"
         ]
         
         static let folders: [Folder] = [
+            .app,
+            .libraryPublic,
+            .libraryPublic,
+            .app,
+            .testCasesPublic,
             .root,
             .root,
+            .libraryInternal,
             .root,
             .root,
+            .libraryInternal,
             .root,
-            .root
+            .root,
+            .testHelpers
         ]
             
 
         static let resourcePaths: [String] = [
+            "Resources/Files/Sources/App",
+            "Resources/Files/Sources/Library",
+            "Resources/Files/Sources/Library",
+            "Resources/Files/Sources/App",
+            "Resources/Files/Sources/Test",
             "Resources/Files/Sources",
             "Resources/Files/Sources",
+            "Resources/Files/Sources/Library",
             "Resources/Files/Sources",
             "Resources/Files/Sources",
+            "Resources/Files/Sources/Library",
             "Resources/Files/Sources",
-            "Resources/Files/Sources"
+            "Resources/Files/Sources",
+            "Resources/Files/Sources/Test"
         ]
     }
 }