lab6: added unit tests and improved testability of EchoServer

.github/workflows/sonarcloud.yml

@@ -72,7 +72,7 @@ jobs:
         run: dotnet build NetSdrClient.sln -c Release --no-restore
       - name: Tests with coverage (OpenCover)
         run: |
-          dotnet test NetSdrClientAppTests/NetSdrClientAppTests.csproj -c Release --no-build `
+          dotnet test NetSdrClient.sln -c Release --no-build `
             /p:CollectCoverage=true `
             /p:CoverletOutput=TestResults/coverage.xml `
             /p:CoverletOutputFormat=opencover

EchoTcpServer/EchoServer.cs

@@ -0,0 +1,88 @@
+namespace EchoTcpServer;
+
+using System;
+using System.Net;
+using System.Net.Sockets;
+using System.Threading;
+using System.Threading.Tasks;
+public class EchoServer
+{
+    private readonly int _initialPort;
+    private TcpListener? _listener;
+    private readonly CancellationTokenSource _cancellationTokenSource;
+
+    public int Port => _listener?.LocalEndpoint is IPEndPoint ep ? ep.Port : _initialPort;
+
+    public EchoServer(int port)
+    {
+        _initialPort = port;
+        _cancellationTokenSource = new CancellationTokenSource();
+    }
+
+    public async Task StartAsync()
+    {
+        _listener = new TcpListener(IPAddress.Any, _initialPort);
+        _listener.Start();
+        Console.WriteLine($"Server started on port {Port}.");
+
+        while (!_cancellationTokenSource.Token.IsCancellationRequested)
+        {
+            try
+            {
+                TcpClient client = await _listener.AcceptTcpClientAsync(_cancellationTokenSource.Token);
+                Console.WriteLine("Client connected.");
+
+                _ = Task.Run(() => HandleClientAsync(client, _cancellationTokenSource.Token));
+            }
+            catch (OperationCanceledException)
+            {
+                break;
+            }
+            catch (ObjectDisposedException)
+            {
+                break;
+            }
+            catch (SocketException ex) when (ex.SocketErrorCode == SocketError.OperationAborted)
+            {
+                break; 
+            }
+        }
+
+        Console.WriteLine("Server shutdown.");
+    }
+
+    private static async Task HandleClientAsync(TcpClient client, CancellationToken token)
+    {
+        using (client)
+        using (NetworkStream stream = client.GetStream())
+        {
+            try
+            {
+                byte[] buffer = new byte[8192];
+                int bytesRead;
+
+                while (!token.IsCancellationRequested && (bytesRead = await stream.ReadAsync(buffer.AsMemory(), token)) > 0)
+                {
+                    await stream.WriteAsync(buffer.AsMemory(0, bytesRead), token);
+                    Console.WriteLine($"Echoed {bytesRead} bytes to the client.");
+                }
+            }
+            catch (Exception ex) when (ex is not OperationCanceledException)
+            {
+                Console.WriteLine($"Error: {ex.Message}");
+            }
+            finally
+            {
+                Console.WriteLine("Client disconnected.");
+            }
+        }
+    }
+
+    public void Stop()
+    {
+        _cancellationTokenSource.Cancel();
+        _listener?.Stop();
+        _cancellationTokenSource.Dispose();
+        Console.WriteLine("Server stopped.");
+    }
+}

EchoTcpServer/Program.cs

@@ -1,88 +1,10 @@
-using System;
-using System.Net;
-using System.Net.Sockets;
-using System.Text;
-using System.Threading;
+namespace EchoTcpServer;
+
+using System;
 using System.Threading.Tasks;
 
-/// <summary>
-/// This program was designed for test purposes only
-/// Not for a review
-/// </summary>
-public class EchoServer
+public static class Program
 {
-    private readonly int _port;
-    private TcpListener _listener;
-    private CancellationTokenSource _cancellationTokenSource;
-
-
-    public EchoServer(int port)
-    {
-        _port = port;
-        _cancellationTokenSource = new CancellationTokenSource();
-    }
-
-    public async Task StartAsync()
-    {
-        _listener = new TcpListener(IPAddress.Any, _port);
-        _listener.Start();
-        Console.WriteLine($"Server started on port {_port}.");
-
-        while (!_cancellationTokenSource.Token.IsCancellationRequested)
-        {
-            try
-            {
-                TcpClient client = await _listener.AcceptTcpClientAsync();
-                Console.WriteLine("Client connected.");
-
-                _ = Task.Run(() => HandleClientAsync(client, _cancellationTokenSource.Token));
-            }
-            catch (ObjectDisposedException)
-            {
-                // Listener has been closed
-                break;
-            }
-        }
-
-        Console.WriteLine("Server shutdown.");
-    }
-
-    private async Task HandleClientAsync(TcpClient client, CancellationToken token)
-    {
-        using (NetworkStream stream = client.GetStream())
-        {
-            try
-            {
-                byte[] buffer = new byte[8192];
-                int bytesRead;
-
-                while (!token.IsCancellationRequested && (bytesRead = await stream.ReadAsync(buffer, 0, buffer.Length, token)) > 0)
-                {
-                    // Echo back the received message
-                    await stream.WriteAsync(buffer, 0, bytesRead, token);
-                    Console.WriteLine($"Echoed {bytesRead} bytes to the client.");
-                }
-            }
-            catch (Exception ex) when (!(ex is OperationCanceledException))
-            {
-                Console.WriteLine($"Error: {ex.Message}");
-            }
-            finally
-            {
-                client.Close();
-                Console.WriteLine("Client disconnected.");
-            }
-        }
-    }
-
-    public void Stop()
-    {
-        _cancellationTokenSource.Cancel();
-        _listener.Stop();
-        _cancellationTokenSource.Dispose();
-        Console.WriteLine("Server stopped.");
-    }
-
     public static async Task Main(string[] args)
     {
         EchoServer server = new EchoServer(5000);
@@ -110,64 +32,4 @@ public static async Task Main(string[] args)
             Console.WriteLine("Sender stopped.");
         }
     }
-}
-
-
-public class UdpTimedSender : IDisposable
-{
-    private readonly string _host;
-    private readonly int _port;
-    private readonly UdpClient _udpClient;
-    private Timer _timer;
-
-    public UdpTimedSender(string host, int port)
-    {
-        _host = host;
-        _port = port;
-        _udpClient = new UdpClient();
-    }
-
-    public void StartSending(int intervalMilliseconds)
-    {
-        if (_timer != null)
-            throw new InvalidOperationException("Sender is already running.");
-
-        _timer = new Timer(SendMessageCallback, null, 0, intervalMilliseconds);
-    }
-
-    ushort i = 0;
-
-    private void SendMessageCallback(object state)
-    {
-        try
-        {
-            //dummy data
-            Random rnd = new Random();
-            byte[] samples = new byte[1024];
-            rnd.NextBytes(samples);
-            i++;
-
-            byte[] msg = (new byte[] { 0x04, 0x84 }).Concat(BitConverter.GetBytes(i)).Concat(samples).ToArray();
-            var endpoint = new IPEndPoint(IPAddress.Parse(_host), _port);
-
-            _udpClient.Send(msg, msg.Length, endpoint);
-            Console.WriteLine($"Message sent to {_host}:{_port} ");
-        }
-        catch (Exception ex)
-        {
-            Console.WriteLine($"Error sending message: {ex.Message}");
-        }
-    }
-
-    public void StopSending()
-    {
-        _timer?.Dispose();
-        _timer = null;
-    }
-
-    public void Dispose()
-    {
-        StopSending();
-        _udpClient.Dispose();
-    }
 }

EchoTcpServer/UdpTimedSender.cs

@@ -0,0 +1,79 @@
+namespace EchoTcpServer;
+
+using System;
+using System.Net;
+using System.Net.Sockets;
+using System.Threading;
+using System.Security.Cryptography;
+
+public class UdpTimedSender : IDisposable
+{
+    private readonly string _host;
+    private readonly int _port;
+    private readonly UdpClient _udpClient;
+    private Timer? _timer;
+    private ushort _messageIndex = 0;
+    private bool _disposed;
+
+    public UdpTimedSender(string host, int port)
+    {
+        _host = host;
+        _port = port;
+        _udpClient = new UdpClient();
+    }
+
+    public void StartSending(int intervalMilliseconds)
+    {
+        ObjectDisposedException.ThrowIf(_disposed, this);
+
+        if (_timer != null)
+            throw new InvalidOperationException("Sender is already running.");
+
+        _timer = new Timer(SendMessageCallback, null, 0, intervalMilliseconds);
+    }
+
+    private void SendMessageCallback(object? state)
+    {
+        try
+        {
+            byte[] samples = new byte[1024];
+            RandomNumberGenerator.Fill(samples);
+            _messageIndex++;
+
+            byte[] msg = [0x04, 0x84, .. BitConverter.GetBytes(_messageIndex), .. samples];
+            var endpoint = new IPEndPoint(IPAddress.Parse(_host), _port);
+
+            _udpClient.Send(msg, msg.Length, endpoint);
+            Console.WriteLine($"Message sent to {_host}:{_port}");
+        }
+        catch (Exception ex)
+        {
+            Console.WriteLine($"Error sending message: {ex.Message}");
+        }
+    }
+
+    public void StopSending()
+    {
+        _timer?.Dispose();
+        _timer = null;
+    }
+
+    protected virtual void Dispose(bool disposing)
+    {
+        if (!_disposed)
+        {
+            if (disposing)
+            {
+                StopSending();
+                _udpClient.Dispose();
+            }
+            _disposed = true;
+        }
+    }
+
+    public void Dispose()
+    {
+        Dispose(disposing: true);
+        GC.SuppressFinalize(this);
+    }
+}