Make IProcess disposable (#3120)

Author: Evangelink

src/Platform/Microsoft.Testing.Platform/Helpers/System/IProcess.cs

@@ -3,7 +3,7 @@
 
 namespace Microsoft.Testing.Platform.Helpers;
 
-internal interface IProcess
+internal interface IProcess : IDisposable
 {
     public event EventHandler Exited;
 

src/Platform/Microsoft.Testing.Platform/Helpers/System/SystemProcess.cs

@@ -5,7 +5,7 @@
 
 namespace Microsoft.Testing.Platform.Helpers;
 
-internal sealed class SystemProcess : IProcess
+internal sealed class SystemProcess : IProcess, IDisposable
 {
     private readonly Process _process;
 
@@ -51,4 +51,6 @@ public void Kill()
     public void Kill()
         => _process.Kill();
 #endif
+
+    public void Dispose() => _process.Dispose();
 }

src/Platform/Microsoft.Testing.Platform/Hosts/TestHostControllersTestHost.cs

@@ -202,7 +202,7 @@ protected override async Task<int> InternalRunAsync()
             processStartInfo.EnvironmentVariables.Add($"{EnvironmentVariableConstants.TESTINGPLATFORM_TESTHOSTCONTROLLER_TESTHOSTPROCESSSTARTTIME}_{currentPID}", testHostProcessStartupTime);
             await _logger.LogDebugAsync($"{EnvironmentVariableConstants.TESTINGPLATFORM_TESTHOSTCONTROLLER_TESTHOSTPROCESSSTARTTIME}_{currentPID} '{testHostProcessStartupTime}'");
             await _logger.LogDebugAsync($"Starting test host process");
-            IProcess testHostProcess = process.Start(processStartInfo);
+            using IProcess testHostProcess = process.Start(processStartInfo);
 
             testHostProcess.Exited += (sender, e) =>
             {