Resolve warnings and use features from .NET 6.

Program.cs

@@ -1,40 +1,34 @@
-using System;
-using System.Net.WebSockets;
+using System.Net.WebSockets;
 using System.Text;
-using System.Threading;
-using System.Threading.Tasks;
-using Microsoft.AspNetCore.Builder;
 using Microsoft.AspNetCore.Hosting.Server;
-using Microsoft.AspNetCore.Http;
 using Microsoft.AspNetCore.Http.Features;
 using Microsoft.AspNetCore.Server.Kestrel.Core;
 using Microsoft.AspNetCore.Server.Kestrel.Transport.Sockets;
 using Microsoft.AspNetCore.WebSockets;
-using Microsoft.Extensions.Logging;
 using Microsoft.Extensions.Logging.Abstractions;
 using Microsoft.Extensions.Options;
 using Microsoft.Extensions.Primitives;
 
-namespace Kestrel
+namespace Kestrel;
+
+class Context
 {
-    class Context
-    {
     public IFeatureCollection features;
 
     public Context(IFeatureCollection features)
     {
         this.features = features;
     }
-    }
+}
 
-    class Application : IHttpApplication<Context>
-    {
-        private WebSocketMiddleware wsMiddleware;
+class Application : IHttpApplication<Context>
+{
+    private readonly WebSocketMiddleware wsMiddleware;
 
     public Application(ILoggerFactory loggerFactory)
     {
         var wsOptions = new WebSocketOptions();
-            wsMiddleware = new WebSocketMiddleware(continueRequest, new OptionsWrapper<WebSocketOptions>(wsOptions),
+        wsMiddleware = new WebSocketMiddleware(ContinueRequest, new OptionsWrapper<WebSocketOptions>(wsOptions),
             loggerFactory);
     }
 
@@ -43,7 +37,7 @@ namespace Kestrel
         return new Context(contextFeatures);
     }
 
-        public void DisposeContext(Context context, Exception exception)
+    public void DisposeContext(Context context, Exception? exception)
     {
     }
 
@@ -53,7 +47,7 @@ namespace Kestrel
         await wsMiddleware.Invoke(httpContext);
     }
 
-        private async Task continueRequest(HttpContext httpContext)
+    private async Task ContinueRequest(HttpContext httpContext)
     {
         if (httpContext.WebSockets.IsWebSocketRequest)
         {
@@ -67,14 +61,14 @@ namespace Kestrel
         else
         {
             httpContext.Response.Headers.Add("Content-Type", new StringValues("text/plain"));
-                await httpContext.Response.Body.WriteAsync(Encoding.ASCII.GetBytes("hello world"));
-            }
+            await httpContext.Response.Body.WriteAsync(Encoding.ASCII.GetBytes("hello world\n"));
         }
     }
+}
 
-    class Program
-    {
-        static async Task Main(string[] args)
+class Program
+{
+    static async Task Main()
     {
         var serverOptions = new KestrelServerOptions();
         serverOptions.ListenAnyIP(8080);
@@ -85,12 +79,10 @@ namespace Kestrel
         var transportFactory = new SocketTransportFactory(
             new OptionsWrapper<SocketTransportOptions>(transportOptions), loggerFactory);
 
-            using (var server = new KestrelServer(new OptionsWrapper<KestrelServerOptions>(serverOptions),
-                transportFactory, loggerFactory))
-            {
+        using var server = new KestrelServer(
+            new OptionsWrapper<KestrelServerOptions>(serverOptions), transportFactory, loggerFactory);
+
         await server.StartAsync(new Application(loggerFactory), CancellationToken.None);
         Console.ReadLine();
     }
-        }
-    }
 }

kestrel.csproj

@@ -2,6 +2,8 @@
 
   <PropertyGroup>
     <TargetFramework>net6.0</TargetFramework>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
   </PropertyGroup>
 
 </Project>