Lab6: EchoServer refactoring for testability + unit tests

.github/workflows/sonarcloud.yml

@@ -1,31 +1,3 @@
-# This workflow uses actions that are not certified by GitHub.
-# They are provided by a third-party and are governed by
-# separate terms of service, privacy policy, and support
-# documentation.
-
-# This workflow helps you trigger a SonarCloud analysis of your code and populates
-# GitHub Code Scanning alerts with the vulnerabilities found.
-# Free for open source project.
-
-# 1. Login to SonarCloud.io using your GitHub account
-
-# 2. Import your project on SonarCloud
-#     * Add your GitHub organization first, then add your repository as a new project.
-#     * Please note that many languages are eligible for automatic analysis,
-#       which means that the analysis will start automatically without the need to set up GitHub Actions.
-#     * This behavior can be changed in Administration > Analysis Method.
-#
-# 3. Follow the SonarCloud in-product tutorial
-#     * a. Copy/paste the Project Key and the Organization Key into the args parameter below
-#          (You'll find this information in SonarCloud. Click on "Information" at the bottom left)
-#
-#     * b. Generate a new token and add it to your Github repository's secrets using the name SONAR_TOKEN
-#          (On SonarCloud, click on your avatar on top-right > My account > Security
-#           or go directly to https://sonarcloud.io/account/security/)
-
-# Feel free to take a look at our documentation (https://docs.sonarcloud.io/getting-started/github/)
-# or reach out to our community forum if you need some help (https://community.sonarsource.com/c/help/sc/9)
-
 name: SonarCloud analysis
 
 on:
@@ -36,14 +8,16 @@ on:
   workflow_dispatch:
 
 permissions:
-  pull-requests: read # allows SonarCloud to decorate PRs with analysis results
+  pull-requests: read
 
 jobs:
   sonar-check:
     name: Sonar Check
-    runs-on: windows-latest   # безпечно для будь-яких .NET проектів
+    runs-on: windows-latest
     steps:
       - uses: actions/checkout@v4
+        env:
+          FORCE_JAVASCRIPT_ACTIONS_TO_NODE24: true
         with: { fetch-depth: 0 }
 
       - uses: actions/setup-dotnet@v4
@@ -56,27 +30,39 @@ jobs:
           dotnet tool install --global dotnet-sonarscanner
           echo "$env:USERPROFILE\.dotnet\tools" >> $env:GITHUB_PATH
           dotnet sonarscanner begin `
-          /k:"ppanchen_NetSdrClient" `
-          /o:"ppanchen" `
+          /k:"MinTins_ReengineeringCourse" `
+          /o:"roman-flakei" `
           /d:sonar.token="${{ secrets.SONAR_TOKEN }}" `
           /d:sonar.cs.opencover.reportsPaths="**/coverage.xml" `
           /d:sonar.cpd.cs.minimumTokens=40 `
           /d:sonar.cpd.cs.minimumLines=5 `
           /d:sonar.exclusions=**/bin/**,**/obj/**,**/sonarcloud.yml `
-          /d:sonar.qualitygate.wait=true
+          /d:sonar.qualitygate.wait=false
         shell: pwsh
+
       # 2) BUILD & TEST
       - name: Restore
         run: dotnet restore NetSdrClient.sln
+
       - name: Build
         run: dotnet build NetSdrClient.sln -c Release --no-restore
-      #- name: Tests with coverage (OpenCover)
-      #  run: |
-      #    dotnet test NetSdrClientAppTests/NetSdrClientAppTests.csproj -c Release --no-build `
-      #      /p:CollectCoverage=true `
-      #      /p:CoverletOutput=TestResults/coverage.xml `
-      #      /p:CoverletOutputFormat=opencover
-      #  shell: pwsh
+
+      - name: Tests NetSdrClientAppTests with coverage
+        run: |
+          dotnet test NetSdrClientAppTests/NetSdrClientAppTests.csproj -c Release --no-build `
+            /p:CollectCoverage=true `
+            /p:CoverletOutput=TestResults/coverage.xml `
+            /p:CoverletOutputFormat=opencover
+        shell: pwsh
+
+      - name: Tests EchoServerTests with coverage
+        run: |
+          dotnet test EchoServerTests/EchoServerTests.csproj -c Release --no-build `
+            /p:CollectCoverage=true `
+            /p:CoverletOutput=TestResults/coverage.xml `
+            /p:CoverletOutputFormat=opencover
+        shell: pwsh
+
       # 3) END: SonarScanner
       - name: SonarScanner End
         run: dotnet sonarscanner end /d:sonar.token="${{ secrets.SONAR_TOKEN }}"

EchoServerTests/EchoServerTests.cs

@@ -0,0 +1,166 @@
+using System.Net.Sockets;
+using System.Threading;
+using System.Threading.Tasks;
+using EchoTcpServer;
+using Moq;
+using NUnit.Framework;
+
+namespace EchoServerTests
+{
+    public class EchoServerTests
+    {
+        private Mock<ITcpListener> _listenerMock = null!;
+        private EchoServer _server = null!;
+
+        [SetUp]
+        public void Setup()
+        {
+            _listenerMock = new Mock<ITcpListener>();
+            _server = new EchoServer(_listenerMock.Object);
+        }
+
+        // ---------------------------------------------------------------
+        // StartAsync — запускає listener і зупиняється при скасуванні
+        // ---------------------------------------------------------------
+
+        [Test]
+        public async Task StartAsync_CallsListenerStart()
+        {
+            // Arrange: AcceptTcpClientAsync кидає ObjectDisposedException одразу
+            // щоб вийти з циклу без реального сокета
+            _listenerMock
+                .Setup(l => l.AcceptTcpClientAsync())
+                .ThrowsAsync(new ObjectDisposedException("listener"));
+
+            // Act
+            await _server.StartAsync();
+
+            // Assert
+            _listenerMock.Verify(l => l.Start(), Times.Once);
+        }
+
+        [Test]
+        public async Task StartAsync_ExitsLoop_OnObjectDisposedException()
+        {
+            // Arrange
+            _listenerMock
+                .Setup(l => l.AcceptTcpClientAsync())
+                .ThrowsAsync(new ObjectDisposedException("listener"));
+
+            // Act — не має зависнути
+            var task = _server.StartAsync();
+            await Task.WhenAny(task, Task.Delay(2000));
+
+            // Assert — метод завершився без timeout
+            Assert.That(task.IsCompleted, Is.True);
+        }
+
+        // ---------------------------------------------------------------
+        // Stop — скасовує токен і зупиняє listener
+        // ---------------------------------------------------------------
+
+        [Test]
+        public void Stop_CallsListenerStop()
+        {
+            // Act
+            _server.Stop();
+
+            // Assert
+            _listenerMock.Verify(l => l.Stop(), Times.Once);
+        }
+
+        [Test]
+        public void Stop_CanBeCalledWithoutStart()
+        {
+            // Act & Assert — не кидає виняток
+            Assert.DoesNotThrow(() => _server.Stop());
+        }
+
+        // ---------------------------------------------------------------
+        // HandleClientAsync — основна логіка echo
+        // ---------------------------------------------------------------
+
+        [Test]
+        public async Task HandleClientAsync_EchoesDataBack()
+        {
+            // Arrange: два TcpClient спілкуються через loopback
+            using var serverSocket = new TcpListener(System.Net.IPAddress.Loopback, 0);
+            serverSocket.Start();
+            int port = ((System.Net.IPEndPoint)serverSocket.LocalEndpoint).Port;
+
+            using var clientTcp = new TcpClient();
+            await clientTcp.ConnectAsync(System.Net.IPAddress.Loopback, port);
+            using var serverClient = await serverSocket.AcceptTcpClientAsync();
+            serverSocket.Stop();
+
+            var cts = new CancellationTokenSource();
+            var handleTask = _server.HandleClientAsync(serverClient, cts.Token);
+
+            // Act: надіслати дані і прочитати echo
+            byte[] sent = new byte[] { 0x01, 0x02, 0x03, 0x04 };
+            var clientStream = clientTcp.GetStream();
+            await clientStream.WriteAsync(sent, 0, sent.Length);
+
+            byte[] received = new byte[sent.Length];
+            int bytesRead = await clientStream.ReadAsync(received, 0, received.Length);
+
+            // Assert
+            Assert.That(bytesRead, Is.EqualTo(sent.Length));
+            Assert.That(received, Is.EqualTo(sent));
+
+            // Cleanup
+            cts.Cancel();
+            clientTcp.Close();
+            await Task.WhenAny(handleTask, Task.Delay(1000));
+        }
+
+        [Test]
+        public async Task HandleClientAsync_StopsOnCancellation()
+        {
+            // Arrange
+            using var serverSocket = new TcpListener(System.Net.IPAddress.Loopback, 0);
+            serverSocket.Start();
+            int port = ((System.Net.IPEndPoint)serverSocket.LocalEndpoint).Port;
+
+            using var clientTcp = new TcpClient();
+            await clientTcp.ConnectAsync(System.Net.IPAddress.Loopback, port);
+            using var serverClient = await serverSocket.AcceptTcpClientAsync();
+            serverSocket.Stop();
+
+            var cts = new CancellationTokenSource();
+
+            // Act: скасувати токен одразу
+            cts.Cancel();
+            var handleTask = _server.HandleClientAsync(serverClient, cts.Token);
+            await Task.WhenAny(handleTask, Task.Delay(2000));
+
+            // Assert — завершилось без зависання
+            Assert.That(handleTask.IsCompleted, Is.True);
+        }
+
+        [Test]
+        public async Task HandleClientAsync_ClosesClientOnCompletion()
+        {
+            // Arrange
+            using var serverSocket = new TcpListener(System.Net.IPAddress.Loopback, 0);
+            serverSocket.Start();
+            int port = ((System.Net.IPEndPoint)serverSocket.LocalEndpoint).Port;
+
+            using var clientTcp = new TcpClient();
+            await clientTcp.ConnectAsync(System.Net.IPAddress.Loopback, port);
+            using var serverClient = await serverSocket.AcceptTcpClientAsync();
+            serverSocket.Stop();
+
+            var cts = new CancellationTokenSource();
+            cts.Cancel();
+
+            // Act
+            await Task.WhenAny(
+                _server.HandleClientAsync(serverClient, cts.Token),
+                Task.Delay(2000));
+
+            // Assert — після завершення клієнт закритий
+            Assert.That(serverClient.Connected, Is.False);
+        }
+    }
+}

EchoServerTests/EchoServerTests.csproj

@@ -0,0 +1,32 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <TargetFramework>net10.0</TargetFramework>
+    <LangVersion>latest</LangVersion>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+    <IsPackable>false</IsPackable>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="coverlet.collector" Version="6.0.4" />
+    <PackageReference Include="coverlet.msbuild" Version="10.0.1">
+      <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
+      <PrivateAssets>all</PrivateAssets>
+    </PackageReference>
+    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="18.6.0" />
+    <PackageReference Include="Moq" Version="4.20.72" />
+    <PackageReference Include="NUnit" Version="4.3.2" />
+    <PackageReference Include="NUnit.Analyzers" Version="4.7.0" />
+    <PackageReference Include="NUnit3TestAdapter" Version="5.0.0" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <Using Include="NUnit.Framework" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\EchoTcpServer\EchoServer.csproj" />
+  </ItemGroup>
+
+</Project>

EchoTcpServer/EchoServer.cs

@@ -0,0 +1,81 @@
+using System;
+using System.Net.Sockets;
+using System.Threading;
+using System.Threading.Tasks;
+
+namespace EchoTcpServer
+{
+    /// <summary>
+    /// TCP echo server. Accepts connections and echoes back all received bytes.
+    /// Refactored for testability: accepts ITcpListener so real socket can be
+    /// replaced with a mock in unit tests.
+    /// </summary>
+    public class EchoServer
+    {
+        private readonly ITcpListener _listener;
+        private readonly CancellationTokenSource _cts;
+
+        public EchoServer(ITcpListener listener)
+        {
+            _listener = listener;
+            _cts = new CancellationTokenSource();
+        }
+
+        public async Task StartAsync()
+        {
+            _listener.Start();
+            Console.WriteLine("Server started.");
+
+            while (!_cts.Token.IsCancellationRequested)
+            {
+                try
+                {
+                    TcpClient client = await _listener.AcceptTcpClientAsync();
+                    Console.WriteLine("Client connected.");
+                    _ = Task.Run(() => HandleClientAsync(client, _cts.Token));
+                }
+                catch (ObjectDisposedException)
+                {
+                    break;
+                }
+            }
+
+            Console.WriteLine("Server shutdown.");
+        }
+
+        // internal — accessible from EchoServerTests via InternalsVisibleTo
+        internal 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)
+                {
+                    await stream.WriteAsync(buffer, 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
+            {
+                client.Close();
+                Console.WriteLine("Client disconnected.");
+            }
+        }
+
+        public void Stop()
+        {
+            _cts.Cancel();
+            _listener.Stop();
+            _cts.Dispose();
+            Console.WriteLine("Server stopped.");
+        }
+    }
+}