Shutdown fixes (#3553)

* Stop generating solutions via -test flag add -generatesolution

* Add TestAppSystem remove Application.InitUnitTest

Avoids some hacks and also makes sure our tests are as close to a real AppSystem as possible.

* Add shutdown unit test

shuts down an re-inits the engine

* Properly dispose native resources hold by managed during shutdown

Should fix a bunch of crashes

* Fix filesystem and networking tests

* StandaloneTest does proper Game Close

* Make sure package tests clean up properly

* Make sure menu scene and resources are released on shutdown

* Report leaked scenes on shutdown

* Ensure DestroyImmediate is not used on scenes

* Fix unmounting in unit tests not clearing native refs

* Force destroy native resource on ResourceLib Clear

engine/Launcher/SboxDev/Launcher.cs

@@ -1,4 +1,5 @@
-using System;
+using Sandbox.Engine;
+using System;
 using System.Diagnostics;
 using System.Linq;
 
@@ -8,6 +9,17 @@ public static class Launcher
 {
 	public static int Main()
 	{
+		if ( HasCommandLineSwitch( "-generatesolution" ) )
+		{
+			NetCore.InitializeInterop( Environment.CurrentDirectory );
+			Bootstrap.InitMinimal( Environment.CurrentDirectory );
+			Project.InitializeBuiltIn( false ).GetAwaiter().GetResult();
+			Project.GenerateSolution().GetAwaiter().GetResult();
+			Managed.SandboxEngine.NativeInterop.Free();
+			EngineFileSystem.Shutdown();
+			return 0;
+		}
+
 		if ( !HasCommandLineSwitch( "-project" ) && !HasCommandLineSwitch( "-test" ) )
 		{
 			// we pass the command line, so we can pass it on to the sbox-launcher (for -game etc)

engine/Sandbox.AppSystem/AppSystem.cs

@@ -1,6 +1,8 @@
 using Sandbox.Diagnostics;
 using Sandbox.Engine;
 using Sandbox.Internal;
+using Sandbox.Network;
+using Sandbox.Rendering;
 using System;
 using System.Globalization;
 using System.Runtime;
@@ -130,15 +132,69 @@ public class AppSystem
 
 	public virtual void Shutdown()
 	{
-		// Shut the games down
+		// Make sure game instance is closed
-		EngineLoop.Exiting();
+		IGameInstanceDll.Current?.CloseGame();
+
+		// Send shutdown event, should allow us to track successful shutdown vs crash
+		{
+			var analytic = new Api.Events.EventRecord( "Exit" );
+			analytic.SetValue( "uptime", RealTime.Now );
+			// We could record a bunch of stats during the session and
+			// submit them here. I'm thinking things like num games played
+			// menus visited, time in menus, time in game, files downloaded.
+			// Things to give us a whole session picture.
+			analytic.Submit();
+		}
+
+		ConVarSystem.SaveAll();
+
+		IToolsDll.Current?.Exiting();
+		IMenuDll.Current?.Exiting();
+		IGameInstanceDll.Current?.Exiting();
+
+		SoundFile.Shutdown();
+		SoundHandle.Shutdown();
+		DedicatedServer.Shutdown();
+
+		// Flush API
+		Api.Shutdown();
+
+		ConVarSystem.ClearNativeCommands();
+
+		// Whatever package still exists needs to fuck off
+		PackageManager.UnmountAll();
+
+		// Clear static resources
+		Texture.DisposeStatic();
+		Model.DisposeStatic();
+		Material.UI.DisposeStatic();
+		Gizmo.GizmoDraw.DisposeStatic();
+		CubemapRendering.DisposeStatic();
+		Graphics.DisposeStatic();
+
+		TextRendering.ClearCache();
+
+		NativeResourceCache.Clear();
+
+		// Renderpipeline may hold onto native resources, clear them out
+		RenderPipeline.ClearPool();
+
+		// Run GC and finalizers to clear any resources held by managed
+		GC.Collect();
+		GC.WaitForPendingFinalizers();
+
+		// Run the queue one more time, since some finalizers queue tasks
+		MainThread.RunQueues();
+
+		// print each scene that is leaked
+		foreach ( var leakedScene in Scene.All )
+		{
+			log.Warning( $"Leaked scene {leakedScene.Id} during shutdown." );
+		}
 
 		// Shut the engine down (close window etc)
 		NativeEngine.EngineGlobal.SourceEngineShutdown( _appSystem, false );
 
-		// Flush the api (close actvity, update stats etc)
-		Api.Shutdown();
-
 		if ( _appSystem.IsValid )
 		{
 			_appSystem.Destroy();
@@ -161,11 +217,14 @@ public class AppSystem
 		Managed.SourceHammer.NativeInterop.Free();
 		Managed.SourceModelDoc.NativeInterop.Free();
 		Managed.SourceAnimgraph.NativeInterop.Free();
+
+		EngineFileSystem.Shutdown();
+		Application.Shutdown();
 	}
 
-	protected void InitGame( AppSystemCreateInfo createInfo )
+	protected void InitGame( AppSystemCreateInfo createInfo, string commandLine = null )
 	{
-		var commandLine = System.Environment.CommandLine;
+		commandLine ??= System.Environment.CommandLine;
 		commandLine = commandLine.Replace( ".dll", ".exe" ); // uck
 
 		_appSystem = CMaterialSystem2AppSystemDict.Create( createInfo.ToMaterialSystem2AppSystemDictCreateInfo() );

engine/Sandbox.AppSystem/StandaloneAppSystem.cs

@@ -68,7 +68,7 @@ public class StandaloneAppSystem : AppSystem
 		// Quit next loop after load, if we are testing
 		else if ( Utility.CommandLine.HasSwitch( "-test-standalone" ) )
 		{
-			Application.Exit();
+			Game.Close();
 		}
 
 		return !wantsToQuit;

engine/Sandbox.AppSystem/TestAppSystem.cs

@@ -0,0 +1,34 @@
+using System;
+using System.Runtime;
+
+namespace Sandbox;
+
+public class TestAppSystem : AppSystem
+{
+	public override void Init()
+	{
+		GCSettings.LatencyMode = GCLatencyMode.SustainedLowLatency;
+		var GameFolder = System.Environment.GetEnvironmentVariable( "FACEPUNCH_ENGINE", EnvironmentVariableTarget.Process );
+		if ( GameFolder is null ) throw new Exception( "FACEPUNCH_ENGINE not found" );
+
+		NetCore.InitializeInterop( GameFolder );
+
+		var nativeDllPath = $"{GameFolder}\\bin\\win64\\";
+		//
+		// Put our native dll path first so that when looking up native dlls we'll
+		// always use the ones from our folder first
+		//
+		var path = System.Environment.GetEnvironmentVariable( "PATH" );
+		path = $"{nativeDllPath};{path}";
+		System.Environment.SetEnvironmentVariable( "PATH", path );
+
+		CreateGame();
+
+		var createInfo = new AppSystemCreateInfo()
+		{
+			Flags = AppSystemFlags.IsGameApp | AppSystemFlags.IsUnitTest
+		};
+
+		InitGame( createInfo, "" );
+	}
+}

engine/Sandbox.Engine/Application.cs

@@ -25,12 +25,6 @@ public static class Application
 	/// </summary>
 	public static bool IsUnitTest { get; private set; }
 
-
-	/// <summary>
-	/// True if we're running a live unit test.
-	/// </summary>
-	internal static bool IsLiveUnitTest { get; private set; }
-
 	/// <summary>
 	/// True if running without a graphics window, such as in a terminal.
 	/// </summary>
@@ -98,106 +92,7 @@ public static class Application
 	/// </summary>
 	public static bool IsVR => VRSystem.IsActive; // garry: I think this is right? But feels like this should be set at startup and never change?
 
-	static CMaterialSystem2AppSystemDict AppSystem;
+	internal static void Initialize( bool dedicated, bool headless, bool toolsMode, bool testMode, bool isRetail )
-
-	/// <summary>
-	/// Called from unit test projects to initialize the engine
-	/// </summary>
-	public static void InitUnitTest<T>( bool withtools = true, bool withRendering = false )
-	{
-		if ( IsInitialized )
-			throw new InvalidOperationException( "Already Initialized" );
-
-		SyncContext.Init();
-		SyncContext.Reset();
-
-		ThreadSafe.MarkMainThread();
-
-		var callingAssembly = Assembly.GetCallingAssembly();
-		var GameFolder = System.Environment.GetEnvironmentVariable( "FACEPUNCH_ENGINE", IsLiveUnitTest ? EnvironmentVariableTarget.User : EnvironmentVariableTarget.Process );
-		if ( GameFolder is null ) throw new Exception( "FACEPUNCH_ENGINE not found" );
-
-		var nativeDllPath = $"{GameFolder}\\bin\\win64\\";
-
-		var native = NativeLibrary.Load( $"{nativeDllPath}engine2.dll" );
-
-		//
-		// Put our native dll path first so that when looking up native dlls we'll
-		// always use the ones from our folder first
-		//
-		var path = System.Environment.GetEnvironmentVariable( "PATH" );
-		path = $"{nativeDllPath};{path}";
-		System.Environment.SetEnvironmentVariable( "PATH", path );
-
-		Api.Init();
-		EngineFileSystem.Initialize( GameFolder );
-		Application.InitializeGame( false, false, false, true, false );
-		NetCore.InitializeInterop( GameFolder );
-
-		Game.InitUnitTest<T>();
-
-		AppSystem = CMaterialSystem2AppSystemDict.Create( new NativeEngine.MaterialSystem2AppSystemDictCreateInfo()
-		{
-			iFlags = NativeEngine.MaterialSystem2AppSystemDictFlags.IsGameApp
-		} );
-
-		AppSystem.SuppressCOMInitialization();
-		AppSystem.SuppressStartupManifestLoad( true );
-		AppSystem.SetModGameSubdir( "core" );
-		AppSystem.SetInTestMode();
-
-		if ( withRendering )
-		{
-			AppSystem.SetDefaultRenderSystemOption( "-vulkan" );
-		}
-
-		if ( !NativeEngine.EngineGlobal.SourceEnginePreInit( "", AppSystem ) )
-		{
-			throw new System.Exception( "SourceEnginePreInit failed" );
-		}
-
-		AppSystem.InitFinishSetupMaterialSystem();
-
-		AppSystem.AddSystem( "engine2", "SceneSystem_002" );
-		AppSystem.AddSystem( "engine2", "SceneUtils_001" );
-		AppSystem.AddSystem( "engine2", "WorldRendererMgr001" );
-
-		NativeLibrary.Free( native );
-
-		if ( withtools )
-		{
-			var sandboxGame = Assembly.Load( "Sandbox.Tools" );
-			sandboxGame.GetType( "Editor.AssemblyInitialize", true, true )
-					.GetMethod( "InitializeUnitTest", BindingFlags.Static | BindingFlags.Public | BindingFlags.NonPublic )
-					.Invoke( null, new[] { callingAssembly } );
-		}
-	}
-
-	internal static void InitLiveUnitTest<T>( bool withtools = true, bool withRendering = false )
-	{
-		Application.IsLiveUnitTest = true;
-		InitUnitTest<T>( withtools, withRendering );
-	}
-
-	/// <summary>
-	/// Called from unit test projects to politely shut down the engine
-	/// </summary>
-	public static void ShutdownUnitTest()
-	{
-		if ( !IsUnitTest )
-		{
-			throw new InvalidOperationException( "Not running a unit test" );
-		}
-
-		if ( AppSystem.IsValid )
-		{
-			NativeEngine.EngineGlobal.SourceEngineShutdown( AppSystem, false );
-			AppSystem.Destroy();
-			AppSystem = default;
-		}
-	}
-
-	internal static void InitializeGame( bool dedicated, bool headless, bool toolsMode, bool testMode, bool isRetail )
 	{
 		if ( IsInitialized )
 			throw new InvalidOperationException( "Already Initialized" );
@@ -213,6 +108,11 @@ public static class Application
 		IsBenchmark = Environment.GetEnvironmentVariable( "SBOX_MODE" ) == "BENCHMARK";
 	}
 
+	internal static void Shutdown()
+	{
+		IsInitialized = false;
+	}
+
 	internal static void TryLoadVersionInfo( string gameFolder )
 	{
 		Version = "0000000";

engine/Sandbox.Engine/Core/Bootstrap.cs

@@ -28,7 +28,7 @@ internal static class Bootstrap
 	/// </summary>
 	internal static void PreInit( CMaterialSystem2AppSystemDict appDict )
 	{
-		Application.InitializeGame( appDict.IsDedicatedServer(), appDict.IsConsoleApp(), appDict.IsInToolsMode(), appDict.IsInTestMode(), EngineGlobal.IsRetail() );
+		Application.Initialize( appDict.IsDedicatedServer(), appDict.IsConsoleApp(), appDict.IsInToolsMode(), appDict.IsInTestMode(), EngineGlobal.IsRetail() );
 
 		try
 		{
@@ -91,16 +91,6 @@ internal static class Bootstrap
 
 				Mounting.Directory.LoadAssemblies();
 			}
-
-			//
-			// In testmode (-test) we want to build the .sln files now because we'll be closed
-			// down after this call.
-			//
-			if ( Application.IsUnitTest )
-			{
-				SyncContext.RunBlocking( Project.InitializeBuiltIn() );
-				SyncContext.RunBlocking( Project.GenerateSolution() );
-			}
 		}
 		catch ( Exception ex )
 		{
@@ -199,9 +189,12 @@ internal static class Bootstrap
 			//
 			{
 				Screen.UpdateFromEngine();
-				Material.UI.Init();
+				Material.UI.InitStatic();
-				Model.Init();
+				Gizmo.GizmoDraw.InitStatic();
-				Texture.InitStaticTextures();
+				Model.InitStatic();
+				Texture.InitStatic();
+				CubemapRendering.InitStatic();
+				Graphics.InitStatic();
 			}
 
 			if ( !Application.IsHeadless && !Application.IsStandalone )
@@ -294,8 +287,6 @@ internal static class Bootstrap
 		}
 	}
 
-
-
 	internal static void InitMinimal( string rootFolder )
 	{
 		Environment.CurrentDirectory = rootFolder;

engine/Sandbox.Engine/Core/EngineLoop.cs

@@ -384,34 +384,6 @@ internal static class EngineLoop
 		}
 	}
 
-	/// <summary>
-	/// Called when the application is shutting down
-	/// </summary>
-	internal static void Exiting()
-	{
-		// Send shutdown event, should allow us to track successful shutdown vs crash
-		{
-			var analytic = new Api.Events.EventRecord( "Exit" );
-			analytic.SetValue( "uptime", RealTime.Now );
-			// We could record a bunch of stats during the session and
-			// submit them here. I'm thinking things like num games played
-			// menus visited, time in menus, time in game, files downloaded.
-			// Things to give us a whole session picture.
-			analytic.Submit();
-		}
-
-		ConVarSystem.SaveAll();
-
-		IToolsDll.Current?.Exiting();
-		IMenuDll.Current?.Exiting();
-		IGameInstanceDll.Current?.Exiting();
-
-		SoundFile.Shutdown();
-		SoundHandle.Shutdown();
-
-		DedicatedServer.Shutdown();
-	}
-
 	/// <summary>
 	/// A console command has arrived, or a convar has changed
 	/// </summary>

engine/Sandbox.Engine/Core/GlobalContext/GlobalContext.cs

@@ -124,6 +124,8 @@ internal partial class GlobalContext
 		oldCts?.Cancel();
 		oldCts?.Dispose();
 
+		ActiveScene = null;
+
 		TaskSource = new TaskSource( 1 );
 
 		EventSystem?.Dispose();
@@ -133,6 +135,9 @@ internal partial class GlobalContext
 
 		Cookies?.Dispose();
 		Cookies = null;
+
+		ResourceSystem?.Clear();
+		ResourceSystem = new ResourceSystem();
 	}
 
 	string _disabledReason;

engine/Sandbox.Engine/Editor/Gizmos/Draw/Draw.cs

@@ -15,10 +15,30 @@ public static partial class Gizmo
 	/// </summary>
 	public sealed partial class GizmoDraw
 	{
-		static Material LineMaterial = Material.Load( "materials/gizmo/line.vmat" );
+		static Material LineMaterial;
-		static Material SolidMaterial = Material.Load( "materials/gizmo/solid.vmat" );
+		static Material SolidMaterial;
-		static Material SpriteMaterial = Material.Load( "materials/gizmo/sprite.vmat" );
+		static Material SpriteMaterial;
-		static Material GridMaterial = Material.Load( "materials/gizmo/grid.vmat" );
+		static Material GridMaterial;
+
+		internal static void InitStatic()
+		{
+			LineMaterial = Material.Load( "materials/gizmo/line.vmat" );
+			SolidMaterial = Material.Load( "materials/gizmo/solid.vmat" );
+			SpriteMaterial = Material.Load( "materials/gizmo/sprite.vmat" );
+			GridMaterial = Material.Load( "materials/gizmo/grid.vmat" );
+		}
+
+		internal static void DisposeStatic()
+		{
+			LineMaterial?.Dispose();
+			LineMaterial = null;
+			SolidMaterial?.Dispose();
+			SolidMaterial = null;
+			SpriteMaterial?.Dispose();
+			SpriteMaterial = null;
+			GridMaterial?.Dispose();
+			GridMaterial = null;
+		}
 
 		internal GizmoDraw()
 		{

engine/Sandbox.Engine/Game/Game/Game.Host.cs

@@ -47,24 +47,6 @@ public static partial class Game
 		set => GlobalContext.Current.NodeLibrary = value;
 	}
 
-
-	/// <summary>
-	/// Initialize for a unit test
-	/// </summary>
-	internal static void InitUnitTest<T>()
-	{
-		GlobalContext.Current.Reset();
-		GlobalContext.Current.LocalAssembly = typeof( T ).Assembly;
-		GlobalContext.Current.UISystem = new UISystem();
-		GlobalContext.Current.InputContext = new InputContext();
-		GlobalContext.Current.InputContext.TargetUISystem = GlobalContext.Current.UISystem;
-
-		Game.InitHost();
-
-		TypeLibrary.AddAssembly( typeof( T ).Assembly, false );
-	}
-
-
 	private static void AddNodesFromAssembly( Assembly asm )
 	{
 		var result = NodeLibrary.AddAssembly( asm );

engine/Sandbox.Engine/Game/Game/Game.cs

@@ -141,21 +141,21 @@ public static partial class Game
 			return;
 		}
 
+		// Might want to queue this up. do it the next frame?
+		// Be aware that this could be called from the GameDll or the MenuDll
+		// So anything here needs to be safe to call from either
+
+		if ( IGameInstance.Current is not null )
+		{
+			IGameInstance.Current.Close();
+			LaunchArguments.Reset();
+		}
+
 		// Standalone mode and Dedicated Server only: exit whole app
 		if ( Application.IsStandalone || Application.IsDedicatedServer )
 		{
 			Application.Exit();
 		}
-
-		// Might want to queue this up. do it the next frame?
-		// Be aware that this could be called from the GameDll or the MenuDll
-		// So anything here needs to be safe to call from either
-
-		if ( IGameInstance.Current is null )
-			return;
-
-		IGameInstance.Current.Close();
-		LaunchArguments.Reset();
 	}
 
 	/// <summary>

engine/Sandbox.Engine/Resources/Material/Material.UI.cs

@@ -40,7 +40,7 @@ namespace Sandbox
 			/// </summary>
 			internal static Material DropShadow { get; set; }
 
-			internal static void Init()
+			internal static void InitStatic()
 			{
 				Basic = FromShader( "shaders/ui_basic.shader" );
 				Box = FromShader( "shaders/ui_cssbox.shader" );
@@ -51,6 +51,26 @@ namespace Sandbox
 				DropShadow = FromShader( "shaders/ui_dropshadow.shader" );
 				BorderWrap = FromShader( "shaders/ui_borderwrap.shader" );
 			}
+
+			internal static void DisposeStatic()
+			{
+				Basic?.Dispose();
+				Basic = null;
+				Box?.Dispose();
+				Box = null;
+				BoxShadow?.Dispose();
+				BoxShadow = null;
+				Text?.Dispose();
+				Text = null;
+				BackdropFilter?.Dispose();
+				BackdropFilter = null;
+				Filter?.Dispose();
+				Filter = null;
+				DropShadow?.Dispose();
+				DropShadow = null;
+				BorderWrap?.Dispose();
+				BorderWrap = null;
+			}
 		}
 	}
 }

engine/Sandbox.Engine/Resources/Material/Material.cs

@@ -41,16 +41,24 @@ public sealed partial class Material : Resource
 	}
 
 	~Material()
+	{
+		Dispose();
+	}
+
+	internal void Dispose()
 	{
 		// kill the native pointer - it does with the native material
 		// we want to reduce the risk that someone is holding on to it.
-		Attributes.Set( default );
+		Attributes?.Set( default );
 		Attributes = null;
 
-		var n = native;
+		if ( !native.IsNull )
-		native = default;
+		{
+			var n = native;
+			native = default;
 
-		MainThread.Queue( () => n.DestroyStrongHandle() );
+			MainThread.Queue( () => n.DestroyStrongHandle() );
+		}
 	}
 
 	/// <summary>

engine/Sandbox.Engine/Resources/Model/Model.Static.cs

@@ -58,11 +58,23 @@ public partial class Model
 	public static Model Error { get; internal set; }
 
 
-	internal static void Init()
+	internal static void InitStatic()
 	{
 		Cube = Load( "models/dev/box.vmdl" );
 		Sphere = Load( "models/dev/sphere.vmdl" );
 		Plane = Load( "models/dev/plane.vmdl" );
 		Error = Load( "models/dev/error.vmdl" );
 	}
+
+	internal static void DisposeStatic()
+	{
+		Cube?.Dispose();
+		Cube = null;
+		Sphere?.Dispose();
+		Sphere = null;
+		Plane?.Dispose();
+		Plane = null;
+		Error?.Dispose();
+		Error = null;
+	}
 }

engine/Sandbox.Engine/Resources/Model/Model.cs

@@ -28,12 +28,20 @@ public sealed partial class Model : Resource
 		SetIdFromResourcePath( Name );
 	}
 
+	internal void Dispose()
+	{
+		if ( !native.IsNull )
+		{
+			var n = native;
+			native = default;
+
+			MainThread.Queue( () => n.DestroyStrongHandle() );
+		}
+	}
+
 	~Model()
 	{
-		var n = native;
+		Dispose();
-		native = default;
-
-		MainThread.Queue( () => n.DestroyStrongHandle() );
 	}
 
 	/// <summary>

engine/Sandbox.Engine/Resources/Resource.cs

@@ -39,13 +39,20 @@ public abstract partial class Resource : IValid, IJsonConvert, BytePack.ISeriali
 	/// </summary>
 	[Hide, JsonIgnore] public virtual bool HasUnsavedChanges => false;
 
-	~Resource()
+	internal void Destroy()
 	{
 		// Unregister on main thread
 		MainThread.Queue( () => { Game.Resources.Unregister( this ); } );
 
 		Manifest?.Dispose();
 		Manifest = default;
+
+		GC.SuppressFinalize( this );
+	}
+
+	~Resource()
+	{
+		Destroy();
 	}
 
 	internal static string FixPath( string filename )

engine/Sandbox.Engine/Resources/ResourceLibrary.cs

@@ -58,13 +58,19 @@ public class ResourceSystem
 
 		var toDispose = ResourceIndex.Values.ToArray();
 
-		ResourceIndex.Clear();
-
 		foreach ( var resource in toDispose.OfType<GameResource>() )
 		{
 			resource.DestroyInternal();
 		}
 
+		foreach ( var resource in toDispose )
+		{
+			// Don't wait/rely for finalizer get rid of this immediately
+			resource.Destroy();
+		}
+
+		ResourceIndex.Clear();
+
 		TypeCache.Clear();
 	}
 

engine/Sandbox.Engine/Resources/Scene/PrefabFile.cs

@@ -67,7 +67,7 @@ public partial class PrefabFile : GameResource
 
 	protected override void OnDestroy()
 	{
-		CachedScene?.DestroyImmediate();
+		CachedScene?.DestroyInternal();
 		CachedScene = null;
 
 		Unregister();

engine/Sandbox.Engine/Resources/Textures/Texture.Static.cs

@@ -23,7 +23,7 @@ public partial class Texture
 	/// </summary>
 	public static Texture Transparent { get; internal set; }
 
-	internal static void InitStaticTextures()
+	internal static void InitStatic()
 	{
 		Invalid = Create( 1, 1 ).WithData( new byte[4] { 255, 0, 255, 255 } ).Finish();
 		White = Create( 1, 1 ).WithData( new byte[4] { 255, 255, 255, 255 } ).Finish();
@@ -31,6 +31,18 @@ public partial class Texture
 		Black = Create( 1, 1 ).WithData( new byte[4] { 0, 0, 0, 255 } ).Finish();
 	}
 
+	internal static void DisposeStatic()
+	{
+		Invalid?.Dispose();
+		Invalid = default;
+		White?.Dispose();
+		White = default;
+		Transparent?.Dispose();
+		Transparent = default;
+		Black?.Dispose();
+		Black = default;
+	}
+
 	internal static Texture Create( string name, bool anonymous, TextureBuilder builder, IntPtr data, int dataSize )
 	{
 		var config = builder._config.GetWithFixes();

engine/Sandbox.Engine/Scene/Components/Mesh/PolygonMesh.cs

@@ -52,8 +52,8 @@ public sealed partial class PolygonMesh : IJsonConvert
 		public int MaterialId { get; set; }
 	}
 
-	private static readonly Material DefaultMaterial = Material.Load( "materials/dev/reflectivity_30.vmat" );
+	private Material DefaultMaterial = Material.Load( "materials/dev/reflectivity_30.vmat" );
-	private static readonly Vector2 DefaultTextureSize = CalculateTextureSize( DefaultMaterial );
+	private Vector2 DefaultTextureSize => CalculateTextureSize( DefaultMaterial );
 
 	private VertexData<Vector3> Positions { get; init; }
 	private HalfEdgeData<Vector2> TextureCoord { get; init; }

engine/Sandbox.Engine/Scene/GameObject/GameObject.Destroy.cs

@@ -110,6 +110,7 @@ public partial class GameObject : IValid
 	/// </summary>
 	public void DestroyImmediate()
 	{
+		Assert.False( this is Scene, "Don't call DestroyImmediate on a scene." );
 		ThreadSafe.AssertIsMainThread();
 
 		Term();

engine/Sandbox.Engine/Scene/Networking/SceneNetworkSystem.cs

@@ -234,10 +234,10 @@ public partial class SceneNetworkSystem : GameNetworkSystem
 			LoadingScreen.Title = "Loading Scene";
 		}
 
-		// Go ahead and destroy the scene immediately (if it exists.)
+		// Go ahead and destroy the scene
 		if ( Game.ActiveScene is not null )
 		{
-			Game.ActiveScene?.DestroyImmediate();
+			Game.ActiveScene?.Destroy();
 			Game.ActiveScene = null;
 		}
 
@@ -408,7 +408,7 @@ public partial class SceneNetworkSystem : GameNetworkSystem
 
 		if ( Game.ActiveScene is not null )
 		{
-			Game.ActiveScene?.DestroyImmediate();
+			Game.ActiveScene?.Destroy();
 			Game.ActiveScene = null;
 		}
 

engine/Sandbox.Engine/Scene/Scene/Scene.cs

@@ -100,6 +100,8 @@ public partial class Scene : GameObject
 
 	internal virtual void DestroyInternal()
 	{
+		_all.Remove( this );
+
 		// Clearing the object index now means we can save time
 		// because we don't have to do it for each object.
 		// Note that we can't do this in Clear because we don't want to
@@ -154,7 +156,6 @@ public partial class Scene : GameObject
 	public IDisposable Push()
 	{
 		ThreadSafe.AssertIsMainThread();
-
 		var old = Game.ActiveScene;
 
 		Game.ActiveScene = this;

engine/Sandbox.Engine/Services/Packages/PackageManager/PackageManager.ActivePackage.cs

@@ -170,9 +170,6 @@ internal static partial class PackageManager
 			MountedFileSystem.Mount( FileSystem );
 			MountedFileSystem.Mount( AssemblyFileSystem );
 
-			if ( Application.IsUnitTest ) // todo: fully init the engine for unit test
-				return;
-
 			// Reload any already resident resources with the ones we've just mounted
 			NativeEngine.g_pResourceSystem.ReloadSymlinkedResidentResources();
 
@@ -199,9 +196,6 @@ internal static partial class PackageManager
 			AssemblyFileSystem.Dispose();
 			AssemblyFileSystem = null;
 
-			if ( Application.IsUnitTest ) // todo: fully init the engine for unit test
-				return;
-
 			// Reload any resident resources that were just unmounted (they shouldn't be used & will appear as an error, or a local variant)
 			NativeEngine.g_pResourceSystem.ReloadSymlinkedResidentResources();
 		}

engine/Sandbox.Engine/Services/Packages/PackageManager/PackageManager.cs

@@ -20,12 +20,6 @@ internal static partial class PackageManager
 	/// </summary>
 	public static event Action<ActivePackage, string> OnPackageInstalledToContext;
 
-	internal static void ResetForUnitTest()
-	{
-		ActivePackages = new();
-		MountedFileSystem = new AggregateFileSystem();
-	}
-
 	static async Task<Package> FetchPackageAsync( string ident, bool localPriority )
 	{
 		if ( localPriority && Package.TryParseIdent( ident, out var parts ) && !parts.local )
@@ -131,6 +125,15 @@ internal static partial class PackageManager
 		}
 	}
 
+	internal static void UnmountAll()
+	{
+		foreach ( var item in ActivePackages.ToArray() )
+		{
+			item.Delete();
+			ActivePackages.Remove( item );
+		}
+	}
+
 	private static async Task InstallDependencies( Package package, PackageLoadOptions options )
 	{
 		HashSet<string> dependancies = new HashSet<string>( StringComparer.OrdinalIgnoreCase );

engine/Sandbox.Engine/Systems/Console/ConVarSystem.Native.cs

@@ -19,6 +19,31 @@ internal static partial class ConVarSystem
 		var command = new NativeCommand( value );
 		AddCommand( command );
 	}
+
+	internal static void ClearNativeCommands()
+	{
+		if ( Members.Count == 0 )
+			return;
+
+		System.Collections.Generic.List<string> nativeKeys = null;
+
+		foreach ( var (name, command) in Members )
+		{
+			if ( command is NativeCommand || command is NativeConVar )
+			{
+				nativeKeys ??= new System.Collections.Generic.List<string>();
+				nativeKeys.Add( name );
+			}
+		}
+
+		if ( nativeKeys is null )
+			return;
+
+		foreach ( var name in nativeKeys )
+		{
+			Members.Remove( name );
+		}
+	}
 }
 
 

engine/Sandbox.Engine/Systems/Filesystem/EngineFileSystem.cs

@@ -44,7 +44,7 @@ internal static class EngineFileSystem
 	/// <summary>
 	/// Don't try to use the filesystem until you've called this!
 	/// </summary>
-	internal static void Initialize( string rootFolder )
+	internal static void Initialize( string rootFolder, bool skipBaseFolderInit = false )
 	{
 		if ( Root != null )
 			throw new System.Exception( "Filesystem Multi-Initialize" );
@@ -52,8 +52,7 @@ internal static class EngineFileSystem
 		Root = new LocalFileSystem( rootFolder );
 		Temporary = new MemoryFileSystem();
 
-		if ( Application.IsUnitTest )
+		if ( skipBaseFolderInit ) return;
-			return;
 
 		if ( Application.IsEditor )
 		{

engine/Sandbox.Engine/Systems/Networking/System/NetworkSystem.Game.cs

@@ -9,7 +9,8 @@ internal partial class NetworkSystem
 
 	public void InitializeGameSystem()
 	{
-		if ( IGameInstanceDll.Current is null )
+		// If we are unit testing we dont want to do any of this for now, this only works with a gamepackage loaded
+		if ( IGameInstanceDll.Current is null || Application.IsUnitTest )
 			return;
 
 		GameSystem = IGameInstanceDll.Current.CreateGameNetworking( this );

engine/Sandbox.Engine/Systems/Networking/Tables/ServerPackages.cs

@@ -11,7 +11,7 @@ namespace Sandbox;
 /// </summary>
 internal class ServerPackages
 {
-	public static ServerPackages Current { get; private set; }
+	public static ServerPackages Current { get; private set; } = new();
 
 	internal record struct ServerPackageInfo();
 	internal StringTable StringTable;
@@ -86,7 +86,7 @@ internal class ServerPackages
 
 	internal ServerPackages()
 	{
-		Assert.IsNull( Current );
+		// WTF???
 		Current = this;
 
 		StringTable = new StringTable( "ServerPackages", true );

engine/Sandbox.Engine/Systems/Render/ComputeShader.cs

@@ -1,4 +1,5 @@
 using NativeEngine;
+using Sandbox.VR;
 
 namespace Sandbox;
 
@@ -25,6 +26,11 @@ public class ComputeShader
 		ComputeMaterial = material;
 	}
 
+	internal void Dispose()
+	{
+		ComputeMaterial.Dispose();
+	}
+
 	/// <summary>
 	/// Dispatch this compute shader using explicit thread counts.
 	/// </summary>

engine/Sandbox.Engine/Systems/Render/CubemapRendering.cs

@@ -1,5 +1,3 @@
-using NativeEngine;
-using System.Linq;
 using Sandbox.Rendering;
 
 namespace Sandbox;
@@ -10,7 +8,18 @@ namespace Sandbox;
 /// </summary>
 internal static class CubemapRendering
 {
-	static ComputeShader EnvmapFilter = new( "envmap_filtering_cs" );
+	static ComputeShader EnvmapFilter;
+
+	internal static void InitStatic()
+	{
+		EnvmapFilter = new( "envmap_filtering_cs" );
+	}
+
+	internal static void DisposeStatic()
+	{
+		EnvmapFilter?.Dispose();
+		EnvmapFilter = null;
+	}
 
 	/// <summary>
 	/// Specifies the quality level for GGX filtering of environment maps.

engine/Sandbox.Engine/Systems/Render/Graphics.MipmapGen.cs

@@ -4,7 +4,18 @@ namespace Sandbox;
 
 public static partial class Graphics
 {
-	internal static ComputeShader MipMapGeneratorShader = new ComputeShader( "downsample_cs" );
+	internal static ComputeShader MipMapGeneratorShader;
+
+	internal static void InitStatic()
+	{
+		MipMapGeneratorShader = new ComputeShader( "downsample_cs" );
+	}
+
+	internal static void DisposeStatic()
+	{
+		MipMapGeneratorShader?.Dispose();
+		MipMapGeneratorShader = null;
+	}
 
 	/// <summary>
 	/// Which method to use when downsampling a texture

engine/Sandbox.Engine/Systems/Render/RenderPipeline/BloomLayer.cs

@@ -46,7 +46,7 @@ internal class BloomDownsampleLayer : ProceduralRenderLayer
 }
 internal class QuarterDepthDownsampleLayer : ProceduralRenderLayer
 {
-	private static Material DepthResolve = Material.Create( "depthresolve", "shaders/depthresolve.shader" );
+	private Material DepthResolve;
 	private bool MSAAInput;
 
 	public QuarterDepthDownsampleLayer()
@@ -55,6 +55,7 @@ internal class QuarterDepthDownsampleLayer : ProceduralRenderLayer
 		Flags |= LayerFlags.NeverRemove | LayerFlags.DoesntModifyColorBuffers;
 		ClearFlags = ClearFlags.Depth | ClearFlags.Stencil;
 		LayerType = SceneLayerType.Opaque;
+		DepthResolve = Material.Create( "depthresolve", "shaders/depthresolve.shader" );
 	}
 
 	public void Setup( ISceneView view, RenderViewport viewport, SceneViewRenderTargetHandle rtDepth, bool msaaInput, RenderTarget rtOutDepth )

engine/Sandbox.Engine/Systems/Render/RenderPipeline/RenderPipeline.Static.cs

@@ -43,4 +43,10 @@ internal partial class RenderPipeline
 		// Return to pool
 		Pool.Enqueue( renderPipeline );
 	}
+
+	internal static void ClearPool()
+	{
+		Pool.Clear();
+		ActivePipelines.Clear();
+	}
 }

engine/Sandbox.Engine/Systems/Render/TextRendering/TextRendering.cs

@@ -95,4 +95,13 @@ public static partial class TextRendering
 
 		//Log.Info( $"TextManager: {total} ({deleted} deleted)" );
 	}
+
+	internal static void ClearCache()
+	{
+		foreach ( var item in Dictionary )
+		{
+			item.Value.Dispose();
+		}
+		Dictionary.Clear();
+	}
 }

engine/Sandbox.GameInstance/Assembly.cs

@@ -10,3 +10,4 @@ using System.Runtime.CompilerServices;
 [assembly: TasksPersistOnContextReset]
 [assembly: InternalsVisibleTo( "Sandbox.Tools" )]
 [assembly: InternalsVisibleTo( "Sandbox.AppSystem" )]
+[assembly: InternalsVisibleTo( "Sandbox.Test" )]

engine/Sandbox.GameInstance/GameInstance.cs

@@ -110,8 +110,8 @@ internal partial class GameInstance : IGameInstance
 
 		if ( activePackage != null && !Application.IsStandalone )
 		{
-			Game.Language.Shutdown();
+			Game.Language?.Shutdown();
-			FileSystem.Mounted.UnMount( activePackage.FileSystem );
+			FileSystem.Mounted?.UnMount( activePackage.FileSystem );
 
 			activePackage = null;
 		}
@@ -121,7 +121,7 @@ internal partial class GameInstance : IGameInstance
 		// Is this the right place for it? Map packages are marked with "game" so they never get unmounted
 		PackageManager.UnmountTagged( "game" );
 
-		GameInstanceDll.Current.OnGameInstanceClosed( this );
+		GameInstanceDll.Current.Shutdown( this );
 
 		Game.Shutdown();
 

engine/Sandbox.GameInstance/GameInstanceDll.cs

@@ -66,7 +66,7 @@ internal partial class GameInstanceDll : Engine.IGameInstanceDll
 			}
 		}
 
-		Assert.IsNull( PackageLoader );
+		PackageLoader?.Dispose();
 		PackageLoader = new PackageLoader( "GameMenu", typeof( GameInstanceDll ).Assembly );
 		PackageLoader.HotloadWatch( Game.GameAssembly ); // Sandbox.Game is per instance
 		PackageLoader.OnAfterHotload = OnAfterHotload;
@@ -234,11 +234,14 @@ internal partial class GameInstanceDll : Engine.IGameInstanceDll
 			}
 		};
 
-		// Clear resource library so resources don't leak between games,
-		// then let IMenuDll reload whatever resources it needs
-
-		Game.Resources.Clear();
 		IMenuDll.Current?.Reset();
+
+		// Run GC and finalizers to clear any native resources held
+		GC.Collect();
+		GC.WaitForPendingFinalizers();
+
+		// Run the queue one more time, since some finalizers queue tasks
+		MainThread.RunQueues();
 	}
 
 	/// <summary>
@@ -700,7 +703,7 @@ internal partial class GameInstanceDll : Engine.IGameInstanceDll
 	/// Called when the game menu is closed
 	/// </summary>
 	/// <param name="instance"></param>
-	public void OnGameInstanceClosed( IGameInstance instance )
+	public void Shutdown( IGameInstance instance )
 	{
 		NativeErrorReporter.Breadcrumb( true, "game", "Closed game instance" );
 		NativeErrorReporter.SetTag( "game", null );

engine/Sandbox.Menu/MenuDll.cs

@@ -211,8 +211,44 @@ internal sealed class MenuDll : IMenuDll
 
 	public void Exiting()
 	{
-		using var scope = PushScope();
+		using ( PushScope() )
-		Game.Cookies?.Save();
+		{
+			// Shutdown menu system
+			IMenuSystem.Current?.Shutdown();
+			IMenuSystem.Current = null;
+
+			// Unregister messaging
+			Sandbox.Services.Messaging.OnMessage -= OnMessageFromBackend;
+
+			// Save and dispose cookies
+			Game.Cookies?.Save();
+			Game.Cookies = null;
+
+			// Cleanup scene
+			MenuScene.Scene?.Destroy();
+			MenuScene.Scene = null;
+
+			// Dispose package loader and enroller
+			Enroller?.Dispose();
+			Enroller = null;
+
+			Loader?.Dispose();
+			Loader = null;
+
+			// Shutdown Steamworks interfaces
+			if ( !Application.IsEditor )
+			{
+				Steamworks.SteamClient.Cleanup();
+			}
+
+			// Expire async context to prevent lingering tasks
+			AsyncContext.Expire( null );
+
+			// Clear global context
+			GlobalContext.Current.Reset();
+
+			IMenuDll.Current = null;
+		}
 	}
 
 	void LoadResources()

engine/Sandbox.Test/ActionGraphs/LiveGamePackage.cs

@@ -2,123 +2,78 @@
 using Sandbox.ActionGraphs;
 using Sandbox.Engine;
 using Sandbox.Internal;
+using Sandbox.Tasks;
 using System;
 using System.Collections.Generic;
+using System.Threading;
 
 namespace ActionGraphs;
 
 [TestClass]
 public class LiveGamePackage
 {
-	[TestInitialize]
-	public void TestInitialize()
-	{
-		Project.Clear();
-		PackageManager.ResetForUnitTest();
-		AssetDownloadCache.Initialize( $"{Environment.CurrentDirectory}/.source2/package_manager_folder" );
-	}
-
-	[TestCleanup]
-	public void TestCleanup()
-	{
-		Game.NodeLibrary = null;
-		GlobalContext.Current.FileMount = null;
-
-		Game.Shutdown();
-	}
-
 	/// <summary>
 	/// Asserts that all the ActionGraphs referenced by a given scene in a downloaded
 	/// package have no errors.
 	/// </summary>
 	[TestMethod]
-	[DataRow( "fish.sauna", 76972L, "scenes/finland.scene", 140,
+	[DataRow( "fish.sauna", 76972L, "scenes/finland.scene", 14,
 		"d174cab5-7a05-476c-a545-4db2fd685032", // Prefab references game object from other scene
 		"e9ac7c29-ff9f-4c3c-8d9d-7228c4711248", // Inventory method changed parameter types
 		"462927b9-1f01-4ba8-9f6b-2e1e6a5934e4"  // Inventory method changed parameter types
 	)]
-	public async Task AssertNoGraphErrorsInScene( string packageName, long? version, string scenePath, int graphCount, params string[] ignoreGuids )
+	public void AssertNoGraphErrorsInScene( string packageName, long? version, string scenePath, int graphCount, params string[] ignoreGuids )
 	{
+		AssetDownloadCache.Initialize( $"{Environment.CurrentDirectory}/.source2/package_manager_folder" );
+
+		PackageManager.UnmountAll();
+		// Let's make sure we have base content mounted
+		IGameInstanceDll.Current?.Bootstrap();
+
 		var ignoreGuidSet = new HashSet<Guid>( ignoreGuids.Select( Guid.Parse ) );
 
-		using ( var packageLoader = new Sandbox.PackageLoader( "Test", GetType().Assembly ) )
+		var packageIdent = version is { } v ? $"{packageName}#{v}" : packageName;
+
+		// Use the production loading logic - run blocking to ensure it completes
+		var loadTask = GameInstanceDll.Current.LoadGamePackageAsync( packageIdent, GameLoadingFlags.Host, CancellationToken.None );
+		SyncContext.RunBlocking( loadTask );
+
+		Assert.IsNotNull( GameInstanceDll.gameInstance, "Game instance should be loaded" );
+		Assert.AreNotEqual( 0, PackageManager.MountedFileSystem.FileCount, "We have package files mounted" );
+		Assert.AreNotEqual( 0, GlobalGameNamespace.TypeLibrary.Types.Count, "Library has classes" );
+
+		var sceneFile = ResourceLibrary.Get<SceneFile>( scenePath );
+		Assert.IsNotNull( sceneFile, "Target scene exists" );
+
+		ActionGraphDebugger.Enabled = true;
+
+		Game.ActiveScene = new Scene();
+		Game.ActiveScene.LoadFromFile( sceneFile.ResourcePath );
+
+		var graphs = ActionGraphDebugger.GetAllGraphs();
+		Assert.AreEqual( graphCount, graphs.Count, "Scene has expected graph count" );
+
+		var anyErrors = false;
+
+		foreach ( var graph in graphs )
 		{
-			using var enroller = packageLoader.CreateEnroller( "test-enroller" );
+			Console.WriteLine( $"{graph.Guid}: {graph.Title} {(ignoreGuidSet.Contains( graph.Guid ) ? "(IGNORED)" : "")}" );
 
-			GlobalContext.Current.FileMount = PackageManager.MountedFileSystem;
+			foreach ( var message in graph.Messages )
-
-			enroller.OnAssemblyAdded = ( a ) =>
 			{
-				Game.TypeLibrary.AddAssembly( a.Assembly, true );
+				Console.WriteLine( $"  {message}" );
-				Game.NodeLibrary.AddAssembly( a.Assembly );
-			};
-
-			Assert.AreEqual( 0, PackageManager.MountedFileSystem.FileCount, "No package files mounted" );
-
-			var downloadOptions = new PackageLoadOptions
-			{
-				PackageIdent = version is { } v ? $"{packageName}#{v}" : packageName,
-				ContextTag = "client",
-				AllowLocalPackages = false
-			};
-
-			var activePackage = await PackageManager.InstallAsync( downloadOptions );
-
-			if ( version is not null )
-			{
-				Assert.AreEqual( version.Value, activePackage.Package.Revision.VersionId );
 			}
 
-			Assert.IsNotNull( activePackage );
+			if ( !ignoreGuidSet.Contains( graph.Guid ) )
-			Assert.AreNotEqual( 0, PackageManager.MountedFileSystem.FileCount, "We have package files mounted" );
-
-			// Load the assemblies into the context
-			enroller.LoadPackage( packageName );
-
-			Assert.AreNotEqual( 0, GlobalGameNamespace.TypeLibrary.Types.Count, "Library has classes" );
-
-			JsonUpgrader.UpdateUpgraders( GlobalGameNamespace.TypeLibrary );
-
-			ResourceLoader.LoadAllGameResource( PackageManager.MountedFileSystem );
-
-			var sceneFile = ResourceLibrary.Get<SceneFile>( scenePath );
-
-			Assert.IsNotNull( sceneFile, "Target scene exists" );
-
-			ActionGraphDebugger.Enabled = true;
-
-			var anyErrors = false;
-
-			Game.ActiveScene = new Scene();
-			Game.ActiveScene.LoadFromFile( sceneFile.ResourcePath );
-
-			var graphs = ActionGraphDebugger.GetAllGraphs();
-
-			Assert.AreEqual( graphCount, graphs.Count, "Scene has expected graph count" );
-
-			foreach ( var graph in graphs )
 			{
-				Console.WriteLine( $"{graph.Guid}: {graph.Title} {(ignoreGuidSet.Contains( graph.Guid ) ? "(IGNORED)" : "")}" );
+				anyErrors |= graph.HasErrors();
-
-				foreach ( var message in graph.Messages )
-				{
-					Console.WriteLine( $"  {message}" );
-				}
-
-				if ( !ignoreGuidSet.Contains( graph.Guid ) )
-				{
-
-					anyErrors |= graph.HasErrors();
-				}
 			}
-
-			ActionGraphDebugger.Enabled = false;
-
-			PackageManager.UnmountTagged( "client" );
-
-			Assert.IsFalse( anyErrors );
 		}
 
-		Assert.AreEqual( 0, PackageManager.MountedFileSystem.FileCount, "Unmounted everything" );
+		ActionGraphDebugger.Enabled = false;
+
+		Assert.IsFalse( anyErrors, "No unexpected graph errors" );
+
+		GameInstanceDll.Current?.CloseGame();
 	}
 }

engine/Sandbox.Test/Engine/Shutdown.cs

@@ -0,0 +1,24 @@
+namespace Misc;
+
+[TestClass]
+public class Shutdown
+{
+	[TestMethod]
+	public void Single()
+	{
+		// We already initialized the app for testing, so we can directly shutdown
+		TestInit.TestAppSystem.Shutdown();
+
+		// We need to re-init because other tests still need it
+		TestInit.TestAppSystem.Init();
+	}
+
+	[TestMethod]
+	public void Multiple()
+	{
+		TestInit.TestAppSystem.Shutdown();
+		TestInit.TestAppSystem.Init();
+		TestInit.TestAppSystem.Shutdown();
+		TestInit.TestAppSystem.Init();
+	}
+}

engine/Sandbox.Test/Filesystem/FileSystem.cs

@@ -18,7 +18,7 @@ public partial class FileSystem
 		System.IO.Directory.CreateDirectory( ".source2/TestFolder" );
 
 		Sandbox.EngineFileSystem.Shutdown();
-		Sandbox.EngineFileSystem.Initialize( ".source2/TestFolder" );
+		Sandbox.EngineFileSystem.Initialize( ".source2/TestFolder", true );
 
 		Sandbox.EngineFileSystem.Root.WriteAllText( "root_text_file.txt", "Hello" );
 

engine/Sandbox.Test/Package/PackageDownload.cs

@@ -5,12 +5,6 @@ namespace Packages;
 [TestClass]
 public class PackageDownload
 {
-	[TestInitialize]
-	public void TestInitialize()
-	{
-		PackageManager.ResetForUnitTest();
-	}
-
 	[TestMethod]
 	[DataRow( "facepunch.sandbox" )]
 	[DataRow( "garry.grassworld" )]

engine/Sandbox.Test/Package/PackageLoader.cs

@@ -10,7 +10,6 @@ public partial class PackageLoader
 	public void TestInitialize()
 	{
 		Project.Clear();
-		PackageManager.ResetForUnitTest();
 		AssetDownloadCache.Initialize( $"{Environment.CurrentDirectory}/.source2/package_manager_folder" );
 	}
 
@@ -94,7 +93,7 @@ public partial class PackageLoader
 		var addonName = "garry.grassworld";
 		var addonClass = "GrassSpawner";
 
-		var (library, _, enroller) = Preamble();
+		var (library, packageLoader, enroller) = Preamble();
 
 		Assert.AreEqual( 0, PackageManager.MountedFileSystem.FileCount, "No package files mounted" );
 
@@ -115,13 +114,16 @@ public partial class PackageLoader
 
 		PackageManager.UnmountTagged( "client" );
 
+		enroller.Dispose();
+		packageLoader.Dispose();
+
 		Assert.AreEqual( 0, PackageManager.MountedFileSystem.FileCount, "Unmounted everything" );
 	}
 
 	//[TestMethod]
 	public async Task LoadPackageWithAddonWithLibrary( string packageName )
 	{
-		var (library, _, enroller) = Preamble();
+		var (library, packageLoader, enroller) = Preamble();
 
 		Assert.AreEqual( 0, PackageManager.MountedFileSystem.FileCount, "No package files mounted" );
 
@@ -138,6 +140,9 @@ public partial class PackageLoader
 
 		PackageManager.UnmountTagged( "client" );
 
+		enroller.Dispose();
+		packageLoader.Dispose();
+
 		Assert.AreEqual( 0, PackageManager.MountedFileSystem.FileCount, "Unmounted everything" );
 	}
 
@@ -150,7 +155,7 @@ public partial class PackageLoader
 	[TestMethod]
 	public async Task LoadRuntimeGamePackage()
 	{
-		var (library, _, enroller) = Preamble();
+		var (library, packageLoader, enroller) = Preamble();
 
 		Project.AddFromFileBuiltIn( "addons/base" );
 		var project = Project.AddFromFile( "unittest/addons/spacewars" );
@@ -170,8 +175,11 @@ public partial class PackageLoader
 		var gameClass = library.GetType( "SpaceWarsGameManager" );
 		Assert.IsNotNull( gameClass, "Found game class" );
 
-		// cleanup
+		enroller.Dispose();
-		PackageManager.UnmountTagged( "client" );
+		packageLoader.Dispose();
+
+		PackageManager.UnmountAll();
+		Assert.AreEqual( 0, PackageManager.MountedFileSystem.FileCount );
 	}
 
 	/// <summary>
@@ -203,6 +211,12 @@ public partial class PackageLoader
 		Assert.IsInstanceOfType<InvalidOperationException>( exception );
 
 		Assert.IsTrue( exception.Message.Contains( "Disabled during static constructors." ) );
+
+		enroller.Dispose();
+		packageLoader.Dispose();
+
+		PackageManager.UnmountAll();
+		Assert.AreEqual( 0, PackageManager.MountedFileSystem.FileCount );
 	}
 
 	//
@@ -328,10 +342,10 @@ public partial class PackageLoader
 
 		//Assert.IsTrue( Project.CompileAsync )
 
-		// cleanup
-		PackageManager.UnmountTagged( "client" );
-
 		packageLoader.Dispose();
+
+		PackageManager.UnmountAll();
+		Assert.AreEqual( 0, PackageManager.MountedFileSystem.FileCount );
 	}
 
 	/// <summary>

engine/Sandbox.Test/Package/PackageManager.cs

@@ -10,7 +10,7 @@ public class PackageManagement
 	[TestInitialize]
 	public void TestInitialize()
 	{
-		PackageManager.ResetForUnitTest();
+		PackageManager.UnmountAll();
 
 		var dir = $"{Environment.CurrentDirectory}/.source2/package_manager_folder";
 
@@ -33,12 +33,6 @@ public class PackageManagement
 		AssetDownloadCache.Initialize( dir );
 	}
 
-	[TestCleanup]
-	public void TestCleanup()
-	{
-
-	}
-
 	/// <summary>
 	/// Should throw an exception on invalid/missing package
 	/// </summary>
@@ -179,9 +173,14 @@ public class PackageManagement
 	[TestMethod]
 	public async Task DownloadPackagesWithMatchingFiles()
 	{
+		var pm = PackageManager.ActivePackages;
+
 		var a = PackageManager.InstallAsync( new PackageLoadOptions( "titanovsky.ufrts_archery2_3", "fff" ) );
 		var b = PackageManager.InstallAsync( new PackageLoadOptions( "titanovsky.ufrts_crates2", "fff" ) );
 
 		await Task.WhenAll( a, b );
+
+		PackageManager.UnmountAll();
+		Assert.AreEqual( 0, PackageManager.MountedFileSystem.FileCount );
 	}
 }

engine/Sandbox.Test/Sandbox.Test.cs

@@ -7,21 +7,18 @@ global using Assert = Microsoft.VisualStudio.TestTools.UnitTesting.Assert;
 [TestClass]
 public class TestInit
 {
+	public static Sandbox.AppSystem TestAppSystem;
+
 	[AssemblyInitialize]
 	public static void ClassInitialize( TestContext context )
 	{
-#if LIVE_UNIT_TEST
+		TestAppSystem = new TestAppSystem();
-		Sandbox.Application.InitLiveUnitTest<TestInit>();
+		TestAppSystem.Init();
-#else
-		Sandbox.Application.InitUnitTest<TestInit>();
-#endif
-
 	}
 
 	[AssemblyCleanup]
 	public static void AssemblyCleanup()
 	{
-		Sandbox.Application.ShutdownUnitTest();
+		TestAppSystem.Shutdown();
-
 	}
 }

engine/Sandbox.Test/Sandbox.Test.csproj

@@ -50,6 +50,7 @@
     <ProjectReference Include="..\Sandbox.Engine\Sandbox.Engine.csproj" />
     <ProjectReference Include="..\Sandbox.Tools\Sandbox.Tools.csproj" />
     <ProjectReference Include="..\Sandbox.Menu\Sandbox.Menu.csproj" />
+    <ProjectReference Include="..\Sandbox.AppSystem\Sandbox.AppSystem.csproj" />
   </ItemGroup>
 
 </Project>

engine/Sandbox.Test/Scene/Components/ModelPhysicsTests.cs

@@ -5,7 +5,7 @@ namespace GameObjects.Components;
 [TestClass]
 public class ModelPhysicsTests
 {
-	private static readonly Model CitizenModel = Model.Load( "models/citizen/citizen.vmdl" );
+	private static Model CitizenModel => Model.Load( "models/citizen/citizen.vmdl" );
 
 	[TestMethod]
 	public void ComponentCreation()

engine/Tools/SboxBuild/Steps/BuildAddons.cs

@@ -13,7 +13,28 @@ internal class BuildAddons( string name ) : Step( name )
 			string rootDir = Directory.GetCurrentDirectory();
 			string gameDir = Path.Combine( rootDir, "game" );
 
-			Log.Info( "Step 1: Building Addons" );
+			Log.Info( "Step 1: Generate solution" );
+
+			string sboxDevPath = Path.Combine( gameDir, "sbox-dev.exe" );
+			if ( !File.Exists( sboxDevPath ) )
+			{
+				Log.Error( $"Error: sbox-dev.exe not found at {sboxDevPath}" );
+				return ExitCode.Failure;
+			}
+
+			bool gameTestSuccess = Utility.RunProcess(
+				sboxDevPath,
+				"-generatesolution",
+				gameDir
+			);
+
+			if ( !gameTestSuccess )
+			{
+				Log.Error( "Solution generation failed!" );
+				return ExitCode.Failure;
+			}
+
+			Log.Info( "Step 2: Building Addons" );
 
 			bool addonsSuccess = Utility.RunDotnetCommand(
 				gameDir,
@@ -26,7 +47,7 @@ internal class BuildAddons( string name ) : Step( name )
 				return ExitCode.Failure;
 			}
 
-			Log.Info( "Step 2: Building Menu" );
+			Log.Info( "Step 3: Building Menu" );
 
 			string menuBuildPath = Path.Combine( gameDir, "bin", "managed", "MenuBuild.exe" );
 			if ( !File.Exists( menuBuildPath ) )

engine/Tools/SboxBuild/Steps/Test.cs

@@ -72,27 +72,6 @@ internal class Test( string name ) : Step( name )
 				return ExitCode.Failure;
 			}
 
-			Log.Info( "Step 3: Testing Game" );
-
-			string sboxDevPath = Path.Combine( gameDir, "sbox-dev.exe" );
-			if ( !File.Exists( sboxDevPath ) )
-			{
-				Log.Error( $"Error: sbox-dev.exe not found at {sboxDevPath}" );
-				return ExitCode.Failure;
-			}
-
-			bool gameTestSuccess = Utility.RunProcess(
-				sboxDevPath,
-				"-test",
-				gameDir
-			);
-
-			if ( !gameTestSuccess )
-			{
-				Log.Error( "Game tests failed!" );
-				return ExitCode.Failure;
-			}
-
 			Log.Info( "All tests completed successfully!" );
 			return ExitCode.Success;
 		}

game/addons/menu/Code/MenuSystem.cs

@@ -48,6 +48,9 @@ public partial class MenuSystem : IMenuSystem
 
 		Dev?.Delete();
 		Dev = null;
+
+		// Null so GC can have it's way
+		Instance = null;
 	}
 
 	Package oldGamePackage;