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
+
+}