WIP

Source/UEST/Private/ScopedGame.cpp

@@ -0,0 +1,82 @@
+#include "ScopedGame.h"
+
+#include "GameMapsSettings.h"
+
+FScopedGameInstance::FScopedGameInstance(TSubclassOf<UGameInstance> GameInstanceClass)
+	: GameInstanceClass{MoveTemp(GameInstanceClass)}
+{
+}
+
+FScopedGameInstance::FScopedGameInstance(FScopedGameInstance&& Other)
+	: GameInstanceClass{MoveTemp(Other.GameInstanceClass)}
+	, Games{MoveTemp(Other.Games)}
+{
+}
+
+FScopedGameInstance::~FScopedGameInstance()
+{
+	for (const auto& Game : Games)
+	{
+		DestroyGameInternal(*Game);
+	}
+}
+
+UGameInstance& FScopedGameInstance::CreateGame()
+{
+	auto Result = NewObject<UGameInstance>(GEngine, GameInstanceClass);
+	Games.Emplace(Result);
+	Result->InitializeStandalone();
+	return *Result;
+}
+
+void FScopedGameInstance::DestroyGameInternal(UGameInstance& Game)
+{
+	Game.Shutdown();
+	Game.GetWorld()->DestroyWorld(true);
+	GEngine->DestroyWorldContext(Game.GetWorld());
+}
+
+bool FScopedGameInstance::DestroyGame(UGameInstance& Game)
+{
+	for (int32 Index = 0; Index < Games.Num(); ++Index)
+	{
+		if (Games[Index].Get() != &Game)
+		{
+			continue;
+		}
+
+		DestroyGameInternal(Game);
+		Games.RemoveAt(Index);
+
+		return true;
+	}
+
+	return ensureMsgf(false, TEXT("Game %s was not registered"), *Game.GetPathName());
+}
+
+void FScopedGameInstance::Tick(const float DeltaSeconds, const float Step, const ELevelTick TickType)
+{
+	StaticTick(DeltaSeconds);
+
+	auto TimeLeftToTick = DeltaSeconds;
+	while (TimeLeftToTick > 0)
+	{
+		const float CurrentStep = FMath::Min(TimeLeftToTick, Step);
+		TimeLeftToTick -= CurrentStep;
+		for (const auto& Game : Games)
+		{
+			Game->GetWorld()->Tick(TickType, CurrentStep);
+		}
+	}
+}
+
+FScopedGame& FScopedGame::WithProjectGameInstance()
+{
+	return WithGameInstance(GetDefault<UGameMapsSettings>()->GameInstanceClass.TryLoadClass<UGameInstance>());
+}
+
+FScopedGameInstance FScopedGame::Build() const
+{
+	FScopedGameInstance Result{GameInstanceClass};
+	return MoveTemp(Result);
+}

Source/UEST/Private/ScopedGameTests.cpp

@@ -0,0 +1,9 @@
+#include "ScopedGame.h"
+#include "UEST.h"
+
+TEST(UEST, ScopedGame, Simple)
+{
+	auto Tester = FScopedGame().Build();
+	auto& Game = Tester.CreateGame();
+	Tester.DestroyGame(Game);
+}

Source/UEST/Public/ScopedGame.h

@@ -0,0 +1,41 @@
+#pragma once
+
+#include "Engine/GameInstance.h"
+
+class FScopedGameInstance : FNoncopyable
+{
+	TSubclassOf<UGameInstance> GameInstanceClass;
+
+	TArray<TStrongObjectPtr<UGameInstance>> Games;
+
+	static void DestroyGameInternal(UGameInstance& Game);
+
+public:
+	FScopedGameInstance(TSubclassOf<UGameInstance> GameInstanceClass);
+
+	FScopedGameInstance(FScopedGameInstance&& Other);
+
+	virtual ~FScopedGameInstance();
+
+	UGameInstance& CreateGame();
+	bool DestroyGame(UGameInstance& Game);
+
+	/** Advances time in all created games by DeltaSeconds in Step increments */
+	void Tick(float DeltaSeconds, float Step, ELevelTick TickType = LEVELTICK_All);
+};
+
+class FScopedGame
+{
+	TSubclassOf<UGameInstance> GameInstanceClass = UGameInstance::StaticClass();
+
+public:
+	FScopedGame& WithGameInstance(TSubclassOf<UGameInstance> InGameInstanceClass)
+	{
+		GameInstanceClass = MoveTemp(InGameInstanceClass);
+		return *this;
+	}
+
+	FScopedGame& WithProjectGameInstance();
+
+	FScopedGameInstance Build() const;
+};