Guard against multiple run invocations

src/SharpIDE.Application/Features/Run/RunService.cs

@@ -1,4 +1,5 @@
-using System.Diagnostics;
+using System.Collections.Concurrent;
+using System.Diagnostics;
 using Ardalis.GuardClauses;
 using AsyncReadProcess.Common;
 using AsyncReadProcess;
@@ -9,14 +10,18 @@ namespace SharpIDE.Application.Features.Run;
 
 public class RunService
 {
-	public HashSet<SharpIdeProjectModel> RunningProjects { get; } = [];
-	// TODO: optimise this Copilot junk
+	private readonly ConcurrentDictionary<SharpIdeProjectModel, SemaphoreSlim> _projectLocks = [];
 	public async Task RunProject(SharpIdeProjectModel project)
 	{
 		Guard.Against.Null(project, nameof(project));
 		Guard.Against.NullOrWhiteSpace(project.FilePath, nameof(project.FilePath), "Project file path cannot be null or empty.");
 		await Task.CompletedTask.ConfigureAwait(ConfigureAwaitOptions.ForceYielding);
 
+		var semaphoreSlim = _projectLocks.GetOrAdd(project, new SemaphoreSlim(1, 1));
+		var waitResult = await semaphoreSlim.WaitAsync(0);
+		if (waitResult is false) throw new InvalidOperationException($"Project {project.Name} is already running.");
+		try
+		{
 			var processStartInfo = new ProcessStartInfo2
 			{
 				FileName = "dotnet",
@@ -49,4 +54,9 @@ public class RunService
 
 			Console.WriteLine("Project ran successfully.");
 		}
+		finally
+		{
+			semaphoreSlim.Release();
+		}
+	}
 }