Allow ValueTask as a return type of the hub method.

src/MagicOnion.Client.Unity/Assets/Scripts/MagicOnion/MagicOnion.Client/MagicOnion.Shared/GrpcMethodHelper.cs

@@ -113,7 +113,6 @@ public static MagicOnionMethod<TRequest, TResponse, TRawRequest, TRawResponse> C
             }
         }
 
-
         // WORKAROUND: Prior to MagicOnion 5.0, the request type for the parameter-less method was byte[].
         //             DynamicClient sends byte[], but GeneratedClient sends Nil, which is incompatible,
         //             so as a special case we do not serialize/deserialize and always convert to a fixed values.
@@ -124,7 +123,7 @@ public static MagicOnionMethod<TRequest, TResponse, TRawRequest, TRawResponse> C
 
                     var writer = ctx.GetBufferWriter();
                     var buffer = writer.GetSpan(unsafeNilBytes.Length); // Write `Nil` as `byte[]` to the buffer.
-                    MagicOnionMarshallers.UnsafeNilBytes.CopyTo(buffer);
+                    unsafeNilBytes.CopyTo(buffer);
                     writer.Advance(unsafeNilBytes.Length);
 
                     ctx.Complete();

src/MagicOnion.Client.Unity/Assets/Scripts/MagicOnion/MagicOnion.Client/MagicOnion.Shared/MagicOnionMarshallers.cs

@@ -24,8 +24,6 @@ public static class MagicOnionMarshallers
             .OrderBy(x => x.GetGenericArguments().Length)
             .ToArray();
 
-        public static readonly byte[] UnsafeNilBytes = new byte[] { MessagePackCode.Nil };
-
         public static readonly Marshaller<byte[]> ThroughMarshaller = new Marshaller<byte[]>(x => x, x => x);
 
         internal static Type CreateRequestType(ParameterInfo[] parameters)

src/MagicOnion.GeneratorCore/CodeAnalysis/MagicOnionTypeInfo.cs

@@ -14,6 +14,7 @@ public static class KnownTypes
         public static MagicOnionTypeInfo System_Boolean { get; } = new MagicOnionTypeInfo("System", "Boolean", SubType.ValueType);
         public static MagicOnionTypeInfo MessagePack_Nil { get; } = new MagicOnionTypeInfo("MessagePack", "Nil", SubType.ValueType);
         public static MagicOnionTypeInfo System_Threading_Tasks_Task { get; } = new MagicOnionTypeInfo("System.Threading.Tasks", "Task");
+        public static MagicOnionTypeInfo System_Threading_Tasks_ValueTask { get; } = new MagicOnionTypeInfo("System.Threading.Tasks", "ValueTask", SubType.ValueType);
         public static MagicOnionTypeInfo MagicOnion_UnaryResult { get; } = new MagicOnionTypeInfo("MagicOnion", "UnaryResult", SubType.ValueType);
         // ReSharper restore InconsistentNaming
     }
@@ -26,6 +27,12 @@ public static class KnownTypes
     public IReadOnlyList<MagicOnionTypeInfo> GenericArguments { get; }
     public bool HasGenericArguments => GenericArguments.Any();
 
+    public MagicOnionTypeInfo GetGenericTypeDefinition()
+    {
+        if (!HasGenericArguments) throw new InvalidOperationException("The type is not constructed generic type.");
+        return MagicOnionTypeInfo.Create(Namespace, Name, Array.Empty<MagicOnionTypeInfo>(), IsValueType);
+    }
+
     public bool IsArray => _subType == SubType.Array;
     public int ArrayRank { get; }
     public MagicOnionTypeInfo ElementType { get; }
@@ -120,6 +127,7 @@ public static MagicOnionTypeInfo Create(string @namespace, string name, MagicOni
         if (@namespace == "System" && name == "String") return KnownTypes.System_String;
         if (@namespace == "System" && name == "Boolean") return KnownTypes.System_Boolean;
         if (@namespace == "System.Threading.Tasks" && name == "Task" && genericArguments.Length == 0) return KnownTypes.System_Threading_Tasks_Task;
+        if (@namespace == "System.Threading.Tasks" && name == "ValueTask" && genericArguments.Length == 0) return KnownTypes.System_Threading_Tasks_ValueTask;
         if (@namespace == "MagicOnion" && name == "UnaryResult" && genericArguments.Length == 0) return KnownTypes.MagicOnion_UnaryResult;
 
         return new MagicOnionTypeInfo(@namespace, name, isValueType ? SubType.ValueType : SubType.None, arrayRank:0, genericArguments);

src/MagicOnion.GeneratorCore/CodeAnalysis/MethodCollector.cs

@@ -85,9 +85,11 @@ MagicOnionStreamingHubInfo.MagicOnionHubMethodInfo CreateHubMethodInfoFromMethod
         switch (methodReturnType.FullNameOpenType)
         {
             case "global::System.Threading.Tasks.Task":
+            case "global::System.Threading.Tasks.ValueTask":
                 //responseType = MagicOnionTypeInfo.KnownTypes.MessagePack_Nil;
                 break;
             case "global::System.Threading.Tasks.Task<>":
+            case "global::System.Threading.Tasks.ValueTask<>":
                 responseType = methodReturnType.GenericArguments[0];
                 break;
             default:

src/MagicOnion.GeneratorCore/CodeGen/StaticStreamingHubClientGenerator.cs

@@ -173,10 +173,30 @@ static void EmitHubMethods(StreamingHubClientBuildContext ctx, bool isFireAndFor
                     _ => $", {method.Parameters.ToNewDynamicArgumentTuple()}",
                 };
 
-                ctx.TextWriter.WriteLines($"""
-                public {method.MethodReturnType.FullName} {method.MethodName}({method.Parameters.ToMethodSignaturize()})
-                    => {(isFireAndForget ? "parent.WriteMessageFireAndForgetAsync" : "base.WriteMessageWithResponseAsync")}<{method.RequestType.FullName}, {method.ResponseType.FullName}>({method.HubId}{writeMessageParameters});
-                """);
+                if (method.MethodReturnType == MagicOnionTypeInfo.KnownTypes.System_Threading_Tasks_ValueTask)
+                {
+                    // ValueTask
+                    ctx.TextWriter.WriteLines($"""
+                    public {method.MethodReturnType.FullName} {method.MethodName}({method.Parameters.ToMethodSignaturize()})
+                        => new global::System.Threading.Tasks.ValueTask({(isFireAndForget ? "parent.WriteMessageFireAndForgetAsync" : "base.WriteMessageWithResponseAsync")}<{method.RequestType.FullName}, {method.ResponseType.FullName}>({method.HubId}{writeMessageParameters}));
+                    """);
+                }
+                else if (method.MethodReturnType.HasGenericArguments && method.MethodReturnType.GetGenericTypeDefinition() == MagicOnionTypeInfo.KnownTypes.System_Threading_Tasks_ValueTask)
+                {
+                    // ValueTask<T>
+                    ctx.TextWriter.WriteLines($"""
+                    public {method.MethodReturnType.FullName} {method.MethodName}({method.Parameters.ToMethodSignaturize()})
+                        => new global::System.Threading.Tasks.ValueTask<{method.ResponseType.FullName}>({(isFireAndForget ? "parent.WriteMessageFireAndForgetAsync" : "base.WriteMessageWithResponseAsync")}<{method.RequestType.FullName}, {method.ResponseType.FullName}>({method.HubId}{writeMessageParameters}));
+                    """);
+                }
+                else
+                {
+                    // Task, Task<T>
+                    ctx.TextWriter.WriteLines($"""
+                    public {method.MethodReturnType.FullName} {method.MethodName}({method.Parameters.ToMethodSignaturize()})
+                        => {(isFireAndForget ? "parent.WriteMessageFireAndForgetAsync" : "base.WriteMessageWithResponseAsync")}<{method.RequestType.FullName}, {method.ResponseType.FullName}>({method.HubId}{writeMessageParameters});
+                    """);
+                }
             } // #endif
         }
 

src/MagicOnion.Server/Hubs/StreamingHubContext.cs

@@ -39,7 +39,7 @@ public ConcurrentDictionary<string, object> Items
     internal Type? responseType;
 
     // helper for reflection
-    internal async ValueTask WriteResponseMessageNil(Task value)
+    internal async ValueTask WriteResponseMessageNil(ValueTask value)
     {
         if (MessageId == -1) // don't write.
         {
@@ -70,7 +70,7 @@ byte[] BuildMessage()
         responseType = typeof(Nil);
     }
 
-    internal async ValueTask WriteResponseMessage<T>(Task<T> value)
+    internal async ValueTask WriteResponseMessage<T>(ValueTask<T> value)
     {
         if (MessageId == -1) // don't write.
         {

src/MagicOnion.Server/Hubs/StreamingHubHandler.cs

@@ -2,6 +2,7 @@
 using MessagePack;
 using System.Linq.Expressions;
 using System.Reflection;
+using System.Runtime.CompilerServices;
 using Grpc.Core;
 using MagicOnion.Server.Filters;
 using MagicOnion.Server.Filters.Internal;
@@ -59,9 +60,7 @@ public StreamingHubHandler(Type classType, MethodInfo methodInfo, StreamingHubHa
             var invokeHubMethodFunc = Expression.Lambda(callHubMethod, contextArg, requestArg).Compile();
 
             // Create a StreamingHub method invoker and a wrapped-invoke method.
-            Type invokerType = metadata.ResponseType is null
-                ? typeof(StreamingHubMethodInvoker<>).MakeGenericType(metadata.RequestType)
-                : typeof(StreamingHubMethodInvoker<,>).MakeGenericType(metadata.RequestType, metadata.ResponseType);
+            Type invokerType = StreamingHubMethodInvoker.CreateInvokerTypeFromMetadata(metadata);
             StreamingHubMethodInvoker invoker = (StreamingHubMethodInvoker)Activator.CreateInstance(invokerType, messageSerializer, invokeHubMethodFunc)!;
 
             var filters = FilterHelper.GetFilters(handlerOptions.GlobalStreamingHubFilters, classType, methodInfo);
@@ -73,23 +72,63 @@ public StreamingHubHandler(Type classType, MethodInfo methodInfo, StreamingHubHa
         }
     }
 
-    abstract class StreamingHubMethodInvoker
+    public override string ToString()
+        => toStringCache;
+
+    public override int GetHashCode()
+        => getHashCodeCache;
+
+    public bool Equals(StreamingHubHandler? other)
+        => other != null && HubName.Equals(other.HubName) && MethodInfo.Name.Equals(other.MethodInfo.Name);
+}
+
+/// <summary>
+/// Options for StreamingHubHandler construction.
+/// </summary>
+public class StreamingHubHandlerOptions
+{
+    public IList<StreamingHubFilterDescriptor> GlobalStreamingHubFilters { get; }
+
+    public IMagicOnionMessageSerializerProvider MessageSerializer { get; }
+
+    public StreamingHubHandlerOptions(MagicOnionOptions options)
     {
-        protected IMagicOnionMessageSerializer MessageSerializer { get; }
+        GlobalStreamingHubFilters = options.GlobalStreamingHubFilters;
+        MessageSerializer = options.MessageSerializer;
+    }
+}
 
-        protected StreamingHubMethodInvoker(IMagicOnionMessageSerializer messageSerializer)
-        {
-            MessageSerializer = messageSerializer;
-        }
+internal abstract class StreamingHubMethodInvoker
+{
+    protected IMagicOnionMessageSerializer MessageSerializer { get; }
 
-        public abstract ValueTask InvokeAsync(StreamingHubContext context);
+    protected StreamingHubMethodInvoker(IMagicOnionMessageSerializer messageSerializer)
+    {
+        MessageSerializer = messageSerializer;
+    }
+
+    public abstract ValueTask InvokeAsync(StreamingHubContext context);
+
+    public static Type CreateInvokerTypeFromMetadata(in StreamingHubMethodHandlerMetadata metadata)
+    {
+        var isTaskOrTaskOfT = metadata.InterfaceMethod.ReturnType == typeof(Task) ||
+                              (metadata.InterfaceMethod.ReturnType is { IsGenericType: true } t && t.BaseType == typeof(Task));
+        return isTaskOrTaskOfT
+            ? (metadata.ResponseType is null
+                ? typeof(StreamingHubMethodInvokerTask<>).MakeGenericType(metadata.RequestType)
+                : typeof(StreamingHubMethodInvokerTask<,>).MakeGenericType(metadata.RequestType, metadata.ResponseType)
+            )
+            : (metadata.ResponseType is null
+                ? typeof(StreamingHubMethodInvokerValueTask<>).MakeGenericType(metadata.RequestType)
+                : typeof(StreamingHubMethodInvokerValueTask<,>).MakeGenericType(metadata.RequestType, metadata.ResponseType)
+            );
     }
 
-    sealed class StreamingHubMethodInvoker<TRequest, TResponse> : StreamingHubMethodInvoker
+    sealed class StreamingHubMethodInvokerTask<TRequest, TResponse> : StreamingHubMethodInvoker
     {
         readonly Func<StreamingHubContext, TRequest, Task<TResponse>> hubMethodFunc;
 
-        public StreamingHubMethodInvoker(IMagicOnionMessageSerializer messageSerializer, Delegate hubMethodFunc) : base(messageSerializer)
+        public StreamingHubMethodInvokerTask(IMagicOnionMessageSerializer messageSerializer, Delegate hubMethodFunc) : base(messageSerializer)
         {
             this.hubMethodFunc = (Func<StreamingHubContext, TRequest, Task<TResponse>>)hubMethodFunc;
         }
@@ -99,15 +138,15 @@ public override ValueTask InvokeAsync(StreamingHubContext context)
             var seq = new ReadOnlySequence<byte>(context.Request);
             TRequest request = MessageSerializer.Deserialize<TRequest>(seq);
             Task<TResponse> response = hubMethodFunc(context, request);
-            return context.WriteResponseMessage(response);
+            return context.WriteResponseMessage(new ValueTask<TResponse>(response));
         }
     }
 
-    sealed class StreamingHubMethodInvoker<TRequest> : StreamingHubMethodInvoker
+    sealed class StreamingHubMethodInvokerTask<TRequest> : StreamingHubMethodInvoker
     {
         readonly Func<StreamingHubContext, TRequest, Task> hubMethodFunc;
 
-        public StreamingHubMethodInvoker(IMagicOnionMessageSerializer messageSerializer, Delegate hubMethodFunc) : base(messageSerializer)
+        public StreamingHubMethodInvokerTask(IMagicOnionMessageSerializer messageSerializer, Delegate hubMethodFunc) : base(messageSerializer)
         {
             this.hubMethodFunc = (Func<StreamingHubContext, TRequest, Task>)hubMethodFunc;
         }
@@ -117,32 +156,44 @@ public override ValueTask InvokeAsync(StreamingHubContext context)
             var seq = new ReadOnlySequence<byte>(context.Request);
             TRequest request = MessageSerializer.Deserialize<TRequest>(seq);
             Task response = hubMethodFunc(context, request);
-            return context.WriteResponseMessageNil(response);
+            return context.WriteResponseMessageNil(new ValueTask(response));
         }
     }
 
-    public override string ToString()
-        => toStringCache;
+    sealed class StreamingHubMethodInvokerValueTask<TRequest, TResponse> : StreamingHubMethodInvoker
+    {
+        readonly Func<StreamingHubContext, TRequest, ValueTask<TResponse>> hubMethodFunc;
 
-    public override int GetHashCode()
-        => getHashCodeCache;
+        public StreamingHubMethodInvokerValueTask(IMagicOnionMessageSerializer messageSerializer, Delegate hubMethodFunc) : base(messageSerializer)
+        {
+            this.hubMethodFunc = (Func<StreamingHubContext, TRequest, ValueTask<TResponse>>)hubMethodFunc;
+        }
 
-    public bool Equals(StreamingHubHandler? other)
-        => other != null && HubName.Equals(other.HubName) && MethodInfo.Name.Equals(other.MethodInfo.Name);
-}
+        public override ValueTask InvokeAsync(StreamingHubContext context)
+        {
+            var seq = new ReadOnlySequence<byte>(context.Request);
+            TRequest request = MessageSerializer.Deserialize<TRequest>(seq);
+            ValueTask<TResponse> response = hubMethodFunc(context, request);
+            return context.WriteResponseMessage(response);
+        }
+    }
 
-/// <summary>
-/// Options for StreamingHubHandler construction.
-/// </summary>
-public class StreamingHubHandlerOptions
-{
-    public IList<StreamingHubFilterDescriptor> GlobalStreamingHubFilters { get; }
+    sealed class StreamingHubMethodInvokerValueTask<TRequest> : StreamingHubMethodInvoker
+    {
+        readonly Func<StreamingHubContext, TRequest, ValueTask> hubMethodFunc;
 
-    public IMagicOnionMessageSerializerProvider MessageSerializer { get; }
+        public StreamingHubMethodInvokerValueTask(IMagicOnionMessageSerializer messageSerializer, Delegate hubMethodFunc) : base(messageSerializer)
+        {
+            this.hubMethodFunc = (Func<StreamingHubContext, TRequest, ValueTask>)hubMethodFunc;
+        }
 
-    public StreamingHubHandlerOptions(MagicOnionOptions options)
-    {
-        GlobalStreamingHubFilters = options.GlobalStreamingHubFilters;
-        MessageSerializer = options.MessageSerializer;
+        public override ValueTask InvokeAsync(StreamingHubContext context)
+        {
+            var seq = new ReadOnlySequence<byte>(context.Request);
+            TRequest request = MessageSerializer.Deserialize<TRequest>(seq);
+            ValueTask response = hubMethodFunc(context, request);
+            return context.WriteResponseMessageNil(response);
+        }
     }
+
 }

src/MagicOnion.Server/Internal/MethodHandlerMetadata.cs

@@ -95,7 +95,7 @@ public static StreamingHubMethodHandlerMetadata CreateStreamingHubMethodHandlerM
     {
         var hubInterface = serviceClass.GetInterfaces().First(x => x.GetTypeInfo().IsGenericType && x.GetGenericTypeDefinition() == typeof(IStreamingHub<,>)).GetGenericArguments()[0];
         var parameters = methodInfo.GetParameters();
-        var responseType = UnwrapStreamingHubResponseType(methodInfo, out var responseIsTask);
+        var responseType = UnwrapStreamingHubResponseType(methodInfo, out var responseIsTaskOrValueTask);
         var requestType = GetRequestTypeFromMethod(methodInfo, parameters);
 
         var attributeLookup = serviceClass.GetCustomAttributes(true)
@@ -105,9 +105,9 @@ public static StreamingHubMethodHandlerMetadata CreateStreamingHubMethodHandlerM
 
         var interfaceMethodInfo = ResolveInterfaceMethod(serviceClass, hubInterface, methodInfo.Name);
 
-        if (!responseIsTask)
+        if (!responseIsTaskOrValueTask)
         {
-            throw new InvalidOperationException($"A type of the StreamingHub method must be Task or Task<T>. (Member:{serviceClass.Name}.{methodInfo.Name})");
+            throw new InvalidOperationException($"A type of the StreamingHub method must be Task, Task<T>, ValueTask or ValueTask<T>. (Member:{serviceClass.Name}.{methodInfo.Name})");
         }
 
         var methodId = interfaceMethodInfo.GetCustomAttribute<MethodIdAttribute>()?.MethodId ?? FNV1A32.GetHashCode(interfaceMethodInfo.Name);
@@ -187,19 +187,19 @@ static Type UnwrapUnaryResponseType(MethodInfo methodInfo, out MethodType method
         throw new InvalidOperationException($"The method '{methodInfo.Name}' has invalid return type. path:{methodInfo.DeclaringType!.Name + "/" + methodInfo.Name} type:{methodInfo.ReturnType.Name}");
     }
 
-    static Type? UnwrapStreamingHubResponseType(MethodInfo methodInfo, out bool responseIsTask)
+    static Type? UnwrapStreamingHubResponseType(MethodInfo methodInfo, out bool responseIsTaskOrValueTask)
     {
         var t = methodInfo.ReturnType;
 
         // Task<T>
-        if (t.IsGenericType && t.GetGenericTypeDefinition() == typeof(Task<>))
+        if (t.IsGenericType && (t.GetGenericTypeDefinition() == typeof(Task<>) || t.GetGenericTypeDefinition() == typeof(ValueTask<>)))
         {
-            responseIsTask = true;
+            responseIsTaskOrValueTask = true;
             return t.GetGenericArguments()[0];
         }
-        else if (t == typeof(Task))
+        else if (t == typeof(Task) || t == typeof(ValueTask))
         {
-            responseIsTask = true;
+            responseIsTaskOrValueTask = true;
             return null;
         }
 

tests/MagicOnion.Generator.Tests/Collector/MagicOnionTypeInfoTest.cs

@@ -698,4 +698,15 @@ public void EnumerateDependentTypes_Generics_Nested()
             MagicOnionTypeInfo.CreateFromType<byte[]>(),
             MagicOnionTypeInfo.CreateFromType<byte>());
     }
+
+    [Fact]
+    public void GetGenericTypeDefinition()
+    {
+        // Arrange
+        var typeInfo = MagicOnionTypeInfo.CreateFromType<ValueTuple<int, string>>();
+        // Act
+        var genericDefinition = typeInfo.GetGenericTypeDefinition();
+        // Assert
+        genericDefinition.Should().Be(MagicOnionTypeInfo.Create("System", "ValueTuple", Array.Empty<MagicOnionTypeInfo>(), true));
+    }
 }