Fix crash with "/" route

Source/SimpleHttpServer/Private/SimpleHttpServer.cpp

@@ -10,6 +10,42 @@
 
 DEFINE_LOG_CATEGORY(LogSimpleHttpServer);
 
+namespace
+{
+	FHttpPath MakeHttpPathForRoute(const FString& HttpPath)
+	{
+		return FHttpPath(HttpPath);
+	}
+
+	FString NormalizeHttpPath(FString InPath)
+	{
+		InPath.TrimStartAndEndInline();
+		if (InPath.IsEmpty())
+		{
+			return TEXT("/");
+		}
+
+		if (!InPath.StartsWith(TEXT("/")))
+		{
+			InPath = TEXT("/") + InPath;
+		}
+
+		while (InPath.Len() > 1 && InPath.EndsWith(TEXT("/")))
+		{
+			InPath.LeftChopInline(1, false);
+		}
+
+		return InPath;
+	}
+
+	bool VerbsMatch(ENativeHttpServerRequestVerbs AllowedVerbs, EHttpServerRequestVerbs RequestVerb)
+	{
+		const uint8 AllowedMask = static_cast<uint8>(AllowedVerbs);
+		const uint8 RequestMask = static_cast<uint8>((ENativeHttpServerRequestVerbs)RequestVerb);
+		return (AllowedMask & RequestMask) != 0;
+	}
+}
+
 void USimpleHttpServer::BeginDestroy()
 {
 	Super::BeginDestroy();
@@ -56,6 +92,12 @@ void USimpleHttpServer::StopServer()
 
 	if (HttpRouter.IsValid())
 	{
+		if (bRootPreprocessorRegistered)
+		{
+			HttpRouter->UnregisterRequestPreprocessor(RootRequestPreprocessorHandle);
+			bRootPreprocessorRegistered = false;
+		}
+
 		// Editor will crash after receive request if you start game from editor, close it and start again.
 		// It is because HttpRouter lived in FHttpServerModule and don't be destroyed on game ending.
 		// When server stopped or being destroyed we must unbind all handlers to prevent errors on the next game start.
@@ -68,22 +110,72 @@ void USimpleHttpServer::StopServer()
 
 void USimpleHttpServer::BindRoute(FString HttpPath, ENativeHttpServerRequestVerbs Verbs, FHttpServerRequestDelegate OnHttpServerRequest)
 {
-	RouteDelegates.Add(HttpPath, OnHttpServerRequest);
+	const FString NormalizedPath = NormalizeHttpPath(HttpPath);
+	RouteDelegates.Add(NormalizedPath, OnHttpServerRequest);
+	if (ENativeHttpServerRequestVerbs* ExistingVerbs = RouteVerbs.Find(NormalizedPath))
+	{
+		*ExistingVerbs = (ENativeHttpServerRequestVerbs)((uint8)(*ExistingVerbs) | (uint8)Verbs);
+	}
+	else
+	{
+		RouteVerbs.Add(NormalizedPath, Verbs);
+	}
 
 	if (HttpRouter.IsValid())
 	{
-		FHttpRouteHandle HttpRouteHandle = HttpRouter->BindRoute(FHttpPath(HttpPath), (EHttpServerRequestVerbs)Verbs,
-#if UE_VERSION_OLDER_THAN(5, 4, 0)
-			[&, HttpPath](const FHttpServerRequest& Request, const FHttpResultCallback& OnComplete)
-			{
-				return HandleRequest(HttpPath, Request, OnComplete);
-			});
-#else
-			FHttpRequestHandler::CreateLambda([&, HttpPath](const FHttpServerRequest& Request, const FHttpResultCallback& OnComplete)
+		if (NormalizedPath == TEXT("/"))
+		{
+			if (!bRootPreprocessorRegistered)
 			{
-				return HandleRequest(HttpPath, Request, OnComplete);
-			}));
-#endif
+				RootRequestPreprocessorHandle = HttpRouter->RegisterRequestPreprocessor(
+					FHttpRequestHandler::CreateLambda([this](const FHttpServerRequest& Request, const FHttpResultCallback& OnComplete)
+					{
+						if (!Request.RelativePath.IsRoot())
+						{
+							return false;
+						}
+
+						if (const ENativeHttpServerRequestVerbs* AllowedVerbs = RouteVerbs.Find(TEXT("/")))
+						{
+							if (!VerbsMatch(*AllowedVerbs, Request.Verb))
+							{
+								return false;
+							}
+						}
+
+						if (RouteDelegates.Contains(TEXT("/")))
+						{
+							return HandleRequest(TEXT("/"), Request, OnComplete);
+						}
+
+						if (RouteHandlers.Contains(TEXT("/")))
+						{
+							return HandleRequestNative(TEXT("/"), Request, OnComplete);
+						}
+
+						return false;
+					}));
+
+				bRootPreprocessorRegistered = true;
+			}
+
+			return;
+		}
+
+		const FHttpPath RoutePath = MakeHttpPathForRoute(NormalizedPath);
+		if (!RoutePath.IsValidPath())
+		{
+			UE_LOG(LogSimpleHttpServer, Error, TEXT("Invalid route path: '%s'. This route will not be bound."), *NormalizedPath);
+			return;
+		}
+
+		FHttpRouteHandle HttpRouteHandle = HttpRouter->BindRoute(RoutePath, (EHttpServerRequestVerbs)Verbs,
+
+		FHttpRequestHandler::CreateLambda([&, NormalizedPath](const FHttpServerRequest& Request, const FHttpResultCallback& OnComplete)
+		{
+			return HandleRequest(NormalizedPath, Request, OnComplete);
+		}));
+
 
 		CreatedRouteHandlers.Add(HttpRouteHandle);
 	}
@@ -95,22 +187,72 @@ void USimpleHttpServer::BindRoute(FString HttpPath, ENativeHttpServerRequestVerb
 
 void USimpleHttpServer::BindRouteNative(FString HttpPath, ENativeHttpServerRequestVerbs Verbs, FHttpRouteHandler Handler)
 {
-	RouteHandlers.Add(HttpPath, Handler);
+	const FString NormalizedPath = NormalizeHttpPath(HttpPath);
+	RouteHandlers.Add(NormalizedPath, Handler);
+	if (ENativeHttpServerRequestVerbs* ExistingVerbs = RouteVerbs.Find(NormalizedPath))
+	{
+		*ExistingVerbs = (ENativeHttpServerRequestVerbs)((uint8)(*ExistingVerbs) | (uint8)Verbs);
+	}
+	else
+	{
+		RouteVerbs.Add(NormalizedPath, Verbs);
+	}
 
 	if (HttpRouter.IsValid())
 	{
-		FHttpRouteHandle HttpRouteHandle = HttpRouter->BindRoute(FHttpPath(HttpPath), (EHttpServerRequestVerbs)Verbs,
-#if UE_VERSION_OLDER_THAN(5, 4, 0)
-			[&, HttpPath](const FHttpServerRequest& Request, const FHttpResultCallback& OnComplete)
-			{
-				return HandleRequestNative(HttpPath, Request, OnComplete);
-			});
-#else
-			FHttpRequestHandler::CreateLambda([&, HttpPath](const FHttpServerRequest& Request, const FHttpResultCallback& OnComplete)
+		if (NormalizedPath == TEXT("/"))
+		{
+			if (!bRootPreprocessorRegistered)
 			{
-				return HandleRequestNative(HttpPath, Request, OnComplete);
-			}));
-#endif
+				RootRequestPreprocessorHandle = HttpRouter->RegisterRequestPreprocessor(
+					FHttpRequestHandler::CreateLambda([this](const FHttpServerRequest& Request, const FHttpResultCallback& OnComplete)
+					{
+						if (!Request.RelativePath.IsRoot())
+						{
+							return false;
+						}
+
+						if (const ENativeHttpServerRequestVerbs* AllowedVerbs = RouteVerbs.Find(TEXT("/")))
+						{
+							if (!VerbsMatch(*AllowedVerbs, Request.Verb))
+							{
+								return false;
+							}
+						}
+
+						if (RouteDelegates.Contains(TEXT("/")))
+						{
+							return HandleRequest(TEXT("/"), Request, OnComplete);
+						}
+
+						if (RouteHandlers.Contains(TEXT("/")))
+						{
+							return HandleRequestNative(TEXT("/"), Request, OnComplete);
+						}
+
+						return false;
+					}));
+
+				bRootPreprocessorRegistered = true;
+			}
+
+			return;
+		}
+
+		const FHttpPath RoutePath = MakeHttpPathForRoute(NormalizedPath);
+		if (!RoutePath.IsValidPath())
+		{
+			UE_LOG(LogSimpleHttpServer, Error, TEXT("Invalid route path: '%s'. This route will not be bound."), *NormalizedPath);
+			return;
+		}
+
+		FHttpRouteHandle HttpRouteHandle = HttpRouter->BindRoute(RoutePath, (EHttpServerRequestVerbs)Verbs,
+
+		FHttpRequestHandler::CreateLambda([&, NormalizedPath](const FHttpServerRequest& Request, const FHttpResultCallback& OnComplete)
+		{
+			return HandleRequestNative(NormalizedPath, Request, OnComplete);
+		}));
+
 
 		CreatedRouteHandlers.Add(HttpRouteHandle);
 	}

Source/SimpleHttpServer/Public/SimpleHttpServer.h

@@ -82,7 +82,7 @@ class SIMPLEHTTPSERVER_API USimpleHttpServer : public UObject
 	bool IsServerStarted() const { return bServerStarted; }
 
 	UFUNCTION(BlueprintCallable, Category = "Simple HTTP Server")
-	void StartServer(int32 ServerPort = 8080);
+	void StartServer(int32 ServerPort = 9080);
 
 	UFUNCTION(BlueprintCallable, Category = "Simple HTTP Server")
 	void StopServer();
@@ -128,10 +128,16 @@ class SIMPLEHTTPSERVER_API USimpleHttpServer : public UObject
 	// Usualy used for c++
 	TMap<FString, FHttpRouteHandler> RouteHandlers;
 
+	// Keep track of verbs for paths that are handled without route binding (e.g. "/").
+	TMap<FString, ENativeHttpServerRequestVerbs> RouteVerbs;
+
 	// Cached Route Handlers. We should unbing them from route on self destroy
 	TArray<FHttpRouteHandle> CreatedRouteHandlers;
 
 	TSharedPtr<class IHttpRouter> HttpRouter;
 
+	FDelegateHandle RootRequestPreprocessorHandle;
+	bool bRootPreprocessorRegistered = false;
+
 	bool bServerStarted = false;
 };