Add a logger to the app and logLevel parameter

.gitignore

@@ -2,6 +2,7 @@
 /.build
 /.swiftpm
 /.vscode
+/.devContainer
 /Packages
 /*.xcodeproj
 xcuserdata/

Sources/App/App.swift

@@ -1,5 +1,6 @@
 import ArgumentParser
 import Hummingbird
+import Logging
 
 @main
 struct App: AsyncParsableCommand, AppArguments {
@@ -9,8 +10,18 @@ struct App: AsyncParsableCommand, AppArguments {
     @Option(name: .shortAndLong)
     var port: Int = 8080
 
+    @Option(name: .shortAndLong)
+    var logLevel: Logger.Level?
+
     func run() async throws {
         let app = buildApplication(self)
         try await app.runService()
     }
 }
+
+/// Extend `Logger.Level` so it can be used as an argument
+#if compiler(>=6.0)
+    extension Logger.Level: @retroactive ExpressibleByArgument {}
+#else
+    extension Logger.Level: ExpressibleByArgument {}
+#endif

Sources/App/Application+build.swift

@@ -1,16 +1,24 @@
 import Hummingbird
+import Logging
 
 /// Application arguments protocol. We use a protocol so we can call
-/// `HBApplication.configure` inside Tests as well as in the App executable. 
+/// `buildApplication` inside Tests as well as in the App executable. 
 /// Any variables added here also have to be added to `App` in App.swift and 
 /// `TestArguments` in AppTest.swift
 public protocol AppArguments {
     var hostname: String { get }
     var port: Int { get }
+    var logLevel: Logger.Level? { get }
 }
 
 public func buildApplication(_ arguments: some AppArguments) -> some ApplicationProtocol {
+    let logger = {
+        var logger = Logger(label: "HB")
+        logger.logLevel = arguments.logLevel ?? .info
+        return logger
+    }()
     let router = Router()
+    // Add health route
     router.get("/health") { _,_ -> HTTPResponse.Status in
         return .ok
     }
@@ -19,7 +27,8 @@ public func buildApplication(_ arguments: some AppArguments) -> some Application
         configuration: .init(
             address: .hostname(arguments.hostname, port: arguments.port),
             serverName: "Hummingbird"
-        )
+        ),
+        logger: logger
     )
     return app
 }

Tests/AppTests/AppTests.swift

@@ -1,12 +1,15 @@
-@testable import App
 import Hummingbird
 import HummingbirdTesting
+import Logging
 import XCTest
 
+@testable import App
+
 final class AppTests: XCTestCase {
     struct TestArguments: AppArguments {
         let hostname = "127.0.0.1"
         let port = 0
+        let logLevel: Logger.Level? = .trace
     }
 
     func testApp() async throws {