Adde mutex when executing PowerShell scripts.

Author: MarkMichaelis

src/Chapter10.Tests/Listing10.17.RegisteringAFinalizerWithProcessExit.Tests.cs

@@ -8,6 +8,8 @@ namespace AddisonWesley.Michaelis.EssentialCSharp.Chapter10.Listing10_17.Tests;
 [TestClass]
 public partial class DisposeTests
 {
+    private static Mutex Mutext { get; } = new (false, typeof(DisposeTests).FullName);
+
     public TestContext TestContext { get; set; } = null!; // Auto-initialized by MSTest.
 
     static string Ps1DirectoryPath { get; } =
@@ -24,8 +26,6 @@ public partial class DisposeTests
     public static void ClassInitialize(TestContext testContext)
     {
         string psOutput;
-        using Mutex mutext = new(true, nameof(Listing10_17));
-        
         // Clean up at the start in case the class cleanup doesn't run (due to debug for example)
         string testStage = "cleanup";
         Assert.AreEqual<int>(0, RunPowerShellScript(testStage, out psOutput),
@@ -38,13 +38,15 @@ public static void ClassInitialize(TestContext testContext)
             Path.Join(Ps1DirectoryPath, ProjectName, $"{ProjectName}.csproj");
         Assert.IsTrue(File.Exists(projectFilePath),
             $"The expected project file, '{projectFilePath}', was not created.");
+
     }
 
     [ClassCleanup]
     public static void ClassCleanup()
     {
         // No return check since an exception here will be ignored.
         RunPowerShellScript("cleanup", out string _);
+        Mutext.Dispose();
     }
 
     [DataTestMethod]
@@ -53,18 +55,25 @@ public static void ClassCleanup()
     [DataRow("gc", GCCalled, DisplayName = "Garbage Collected called")]
     public void FinalizerRunsAsPredicted_ConsoleOutputIsInOrder(string finalizerOrderOption, string expectedOutput)
     {
-        using Mutex mutext = new(true, nameof(Listing10_17));
-        int traceValue = 0;
-        string testStatus = "run";
-
-        TestContext.WriteLine($"Ps1Path = '{Path.GetFullPath(Ps1Path)}'");
-        int exitCode = RunPowerShellScript(
-            testStatus, finalizerOrderOption, traceValue, out string psOutput);
-
-        Assert.AreEqual(0, exitCode, $"PowerShell Output: {psOutput}");
-
-        Assert.AreEqual<string>(RemoveWhiteSpace(expectedOutput), RemoveWhiteSpace(psOutput),
-            $"Unexpected output from '{Ps1Path} {traceValue} {finalizerOrderOption} {testStatus}:{Environment.NewLine}{psOutput}");
+        try
+        {
+            Mutext.WaitOne();
+            int traceValue = 0;
+            string testStatus = "run";
+
+            TestContext.WriteLine($"Ps1Path = '{Path.GetFullPath(Ps1Path)}'");
+            int exitCode = RunPowerShellScript(
+                testStatus, finalizerOrderOption, traceValue, out string psOutput);
+
+            Assert.AreEqual(0, exitCode, $"PowerShell Output: {psOutput}");
+
+            Assert.AreEqual<string>(RemoveWhiteSpace(expectedOutput), RemoveWhiteSpace(psOutput),
+                $"Unexpected output from '{Ps1Path} {traceValue} {finalizerOrderOption} {testStatus}:{Environment.NewLine}{psOutput}");
+        }
+        finally
+        {
+            Mutext.ReleaseMutex();
+        }
     }
 
     private static int RunPowerShellScript(string testStage, out string psOutput) =>

src/Shared/Tests/PowerShellTestUtilities.cs

@@ -5,12 +5,14 @@ namespace AddisonWesley.Michaelis.EssentialCSharp.Shared.Tests
 {
     public class PowerShellTestUtilities
     {
+        private readonly static Mutex Mutext = new (false, typeof(PowerShellTestUtilities).FullName);
+        
         public static bool WindowsEnvironment()
         {
             return RuntimeInformation.IsOSPlatform(OSPlatform.Windows);
         }
-
-        public static Lazy<string?> _PowerShellCommand = new(() =>
+        
+        private readonly static Lazy<string?> _PowerShellCommand = new(() =>
         {
             string? powershellCommand = null;
             // Verify that the PowerShell command executes successfully.
@@ -35,14 +37,13 @@ public static bool WindowsEnvironment()
             return powershellCommand;
         });
         public static int RunPowerShellScript(string scriptPath, string arguments) =>
-            RunPowerShellScript(scriptPath, arguments, out string psOutput);
+            RunPowerShellScript(scriptPath, arguments, out string _);
 
         public static int RunPowerShellScript(string scriptPath, string arguments, out string psOutput)
         {
-            using Mutex mutext = new(false, typeof(PowerShellTestUtilities).FullName);
             try
             {
-                mutext.WaitOne();
+                Mutext.WaitOne();
                 if (PowerShellCommand is null)
                 {
                     throw new InvalidOperationException("PowerShell is not installed");
@@ -71,7 +72,7 @@ public static int RunPowerShellScript(string scriptPath, string arguments, out s
             }
             finally
             {
-                mutext.ReleaseMutex();
+                Mutext.ReleaseMutex();
             }
         }