Merge branch 'release/3.0' into develop

Examples/01-PublishSubscribe/01-PublishSubscribe.csproj

@@ -2,16 +2,16 @@
 
   <PropertyGroup>
     <OutputType>Exe</OutputType>
-    <TargetFramework>net5.0</TargetFramework>
+    <TargetFramework>net6.0</TargetFramework>
     <RootNamespace>_01_PublishSubscribe</RootNamespace>
+    <Nullable>enable</Nullable>
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="Autofac" Version="6.2.0" />
+    <PackageReference Include="Autofac" Version="6.5.0" />
-    <PackageReference Include="Castle.Windsor" Version="5.1.1" />
+    <PackageReference Include="Castle.Windsor" Version="5.1.2" />
-    <PackageReference Include="Ninject" Version="3.3.4" />
+    <PackageReference Include="Ninject" Version="3.3.6" />
-    <PackageReference Include="SimpleInjector" Version="5.3.0" />
+    <PackageReference Include="SimpleInjector" Version="5.4.1" />
-    <PackageReference Include="Unity" Version="5.11.10" />
   </ItemGroup>
 
   <ItemGroup>
@@ -20,7 +20,6 @@
     <ProjectReference Include="..\..\Tapeti.DataAnnotations\Tapeti.DataAnnotations.csproj" />
     <ProjectReference Include="..\..\Tapeti.Ninject\Tapeti.Ninject.csproj" />
     <ProjectReference Include="..\..\Tapeti.SimpleInjector\Tapeti.SimpleInjector.csproj" />
-    <ProjectReference Include="..\..\Tapeti.UnityContainer\Tapeti.UnityContainer.csproj" />
     <ProjectReference Include="..\..\Tapeti\Tapeti.csproj" />
     <ProjectReference Include="..\ExampleLib\ExampleLib.csproj" />
     <ProjectReference Include="..\Messaging.TapetiExample\Messaging.TapetiExample.csproj" />

Examples/01-PublishSubscribe/Program.cs

@@ -13,8 +13,6 @@ using Tapeti.DataAnnotations;
 using Tapeti.Default;
 using Tapeti.Ninject;
 using Tapeti.SimpleInjector;
-using Tapeti.UnityContainer;
-using Unity;
 using Container = SimpleInjector.Container;
 
 // ReSharper disable UnusedMember.Global
@@ -23,14 +21,13 @@ namespace _01_PublishSubscribe
 {
     public class Program
     {
-        public static void Main(string[] args)
+        public static void Main()
         {
             var dependencyResolver = GetSimpleInjectorDependencyResolver();
 
             // or use your IoC container of choice:
             //var dependencyResolver = GetAutofacDependencyResolver();
             //var dependencyResolver = GetCastleWindsorDependencyResolver();
-            //var dependencyResolver = GetUnityDependencyResolver();
             //var dependencyResolver = GetNinjectDependencyResolver();
 
             // This helper is used because this example is not run as a service. You do not
@@ -47,7 +44,7 @@ namespace _01_PublishSubscribe
                 .RegisterAllControllers()
                 .Build();
 
-            using (var connection = new TapetiConnection(config)
+            await using var connection = new TapetiConnection(config)
             {
                 // Params is optional if you want to use the defaults, but we'll set it 
                 // explicitly for this example
@@ -63,8 +60,8 @@ namespace _01_PublishSubscribe
                         { "example", "01 - Publish Subscribe" }
                     }
                 }
-            })
+            };
-            {
+
             // IoC containers that separate the builder from the resolver (Autofac) must be built after
             // creating a TapetConnection, as it modifies the container by injecting IPublisher.
             (dependencyResolver as AutofacDependencyResolver)?.Build();
@@ -85,7 +82,6 @@ namespace _01_PublishSubscribe
             // Wait for the controller to signal that the message has been received
             await waitForDone();
         }
-        }
 
 
         internal static IDependencyContainer GetSimpleInjectorDependencyResolver()
@@ -132,17 +128,6 @@ namespace _01_PublishSubscribe
         }
 
 
-        internal static IDependencyContainer GetUnityDependencyResolver()
-        {
-            var container = new UnityContainer();
-
-            container.RegisterType<ILogger, ConsoleLogger>();
-            container.RegisterType<ExamplePublisher>();
-
-            return new UnityDependencyResolver(container);
-        }
-
-
         internal static IDependencyContainer GetNinjectDependencyResolver()
         {
             var kernel = new StandardKernel();

Examples/02-DeclareDurableQueues/02-DeclareDurableQueues.csproj

@@ -2,12 +2,13 @@
 
   <PropertyGroup>
     <OutputType>Exe</OutputType>
-    <TargetFramework>net5.0</TargetFramework>
+    <TargetFramework>net6.0</TargetFramework>
     <RootNamespace>_02_DeclareDurableQueues</RootNamespace>
+    <Nullable>enable</Nullable>
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="SimpleInjector" Version="5.3.0" />
+    <PackageReference Include="SimpleInjector" Version="5.4.1" />
   </ItemGroup>
 
   <ItemGroup>

Examples/02-DeclareDurableQueues/Program.cs

@@ -11,7 +11,7 @@ namespace _02_DeclareDurableQueues
 {
     public class Program
     {
-        public static void Main(string[] args)
+        public static void Main()
         {
             var container = new Container();
             var dependencyResolver = new SimpleInjectorDependencyResolver(container);
@@ -30,8 +30,8 @@ namespace _02_DeclareDurableQueues
                 .EnableDeclareDurableQueues()
                 .Build();
 
-            using (var connection = new TapetiConnection(config))
+            await using var connection = new TapetiConnection(config);
-            {
+
             // This creates or updates the durable queue
             await connection.Subscribe();
 
@@ -44,5 +44,4 @@ namespace _02_DeclareDurableQueues
             await waitForDone();
         }
     }
-    }
 }

Examples/03-FlowRequestResponse/03-FlowRequestResponse.csproj

@@ -2,12 +2,13 @@
 
   <PropertyGroup>
     <OutputType>Exe</OutputType>
-    <TargetFramework>net5.0</TargetFramework>
+    <TargetFramework>net6.0</TargetFramework>
     <RootNamespace>_03_FlowRequestResponse</RootNamespace>
+    <Nullable>enable</Nullable>
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="SimpleInjector" Version="5.3.0" />
+    <PackageReference Include="SimpleInjector" Version="5.4.1" />
   </ItemGroup>
 
   <ItemGroup>

Examples/03-FlowRequestResponse/ParallelFlowController.cs

@@ -15,9 +15,9 @@ namespace _03_FlowRequestResponse
         private readonly IFlowProvider flowProvider;
         private readonly IExampleState exampleState;
 
-        public string FirstQuote;
+        public string? FirstQuote;
-        public string SecondQuote;
+        public string? SecondQuote;
-        public string ThirdQuote;
+        public string? ThirdQuote;
 
 
         public ParallelFlowController(IFlowProvider flowProvider, IExampleState exampleState)
@@ -56,7 +56,7 @@ namespace _03_FlowRequestResponse
 
 
         [Continuation]
-        public async Task HandleSecondQuoteResponse(QuoteResponseMessage message, IFlowParallelRequest parallelRequest)
+        public async ValueTask HandleSecondQuoteResponse(QuoteResponseMessage message, IFlowParallelRequest parallelRequest)
         {
             Console.WriteLine("[ParallelFlowController] Second quote response received");
             SecondQuote = message.Quote;

Examples/03-FlowRequestResponse/Program.cs

@@ -12,7 +12,7 @@ namespace _03_FlowRequestResponse
 {
     public class Program
     {
-        public static void Main(string[] args)
+        public static void Main()
         {
             var container = new Container();
             var dependencyResolver = new SimpleInjectorDependencyResolver(container);
@@ -33,8 +33,8 @@ namespace _03_FlowRequestResponse
                 .Build();
 
 
-            using (var connection = new TapetiConnection(config))
+            await using var connection = new TapetiConnection(config);
-            {
+
             // Must be called before using any flow. When using a persistent repository like the
             // SQL server implementation, you can run any required update scripts (for example, using DbUp)
             // before calling this Load method.
@@ -62,5 +62,4 @@ namespace _03_FlowRequestResponse
             await waitForDone();
         }
     }
-    }
 }

Examples/03-FlowRequestResponse/ReceivingMessageController.cs

@@ -9,25 +9,16 @@ namespace _03_FlowRequestResponse
     public class ReceivingMessageController
     {
         // No publisher required, responses can simply be returned
-        public async Task<QuoteResponseMessage> HandleQuoteRequest(QuoteRequestMessage message)
+        public static async Task<QuoteResponseMessage> HandleQuoteRequest(QuoteRequestMessage message)
         {
-            string quote;
+            var quote = message.Amount switch
-
-            switch (message.Amount)
             {
-                case 1:
+                1 =>
                     // Well, they asked for it... :-)
-                    quote = "'";
+                    "'",
-                    break;
+                2 => "\"",
-                
+                _ => new string('\'', message.Amount)
-                case 2:
+            };
-                    quote = "\"";
-                    break;
-
-                default:
-                    quote = new string('\'', message.Amount);
-                    break;
-            }
 
             // Just gonna let them wait for a bit, to demonstrate async message handlers
             await Task.Delay(1000);

Examples/04-Transient/04-Transient.csproj

@@ -2,12 +2,13 @@
 
   <PropertyGroup>
     <OutputType>Exe</OutputType>
-    <TargetFramework>net5.0</TargetFramework>
+    <TargetFramework>net6.0</TargetFramework>
     <RootNamespace>_04_Transient</RootNamespace>
+    <Nullable>enable</Nullable>
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="SimpleInjector" Version="5.3.0" />
+    <PackageReference Include="SimpleInjector" Version="5.4.1" />
   </ItemGroup>
 
   <ItemGroup>

Examples/04-Transient/Program.cs

@@ -13,7 +13,7 @@ namespace _04_Transient
 {
     public class Program
     {
-        public static void Main(string[] args)
+        public static void Main()
         {
             var container = new Container();
             var dependencyResolver = new SimpleInjectorDependencyResolver(container);
@@ -34,8 +34,7 @@ namespace _04_Transient
                 .Build();
 
 
-            using (var connection = new TapetiConnection(config))
+            await using var connection = new TapetiConnection(config);
-            {
             await connection.Subscribe();
 
 
@@ -51,5 +50,4 @@ namespace _04_Transient
             // Unlike the other example, there is no need to call waitForDone, once we're here the response has been handled.
         }
     }
-    }
 }

Examples/05-SpeedTest/05-SpeedTest.csproj

@@ -2,12 +2,13 @@
 
   <PropertyGroup>
     <OutputType>Exe</OutputType>
-    <TargetFramework>net5.0</TargetFramework>
+    <TargetFramework>net6.0</TargetFramework>
     <RootNamespace>_05_SpeedTest</RootNamespace>
+    <Nullable>enable</Nullable>
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="SimpleInjector" Version="5.3.0" />
+    <PackageReference Include="SimpleInjector" Version="5.4.1" />
   </ItemGroup>
 
   <ItemGroup>

Examples/05-SpeedTest/Program.cs

@@ -21,7 +21,7 @@ namespace _05_SpeedTest
         private const int ConcurrentTasks = 20;
 
 
-        public static void Main(string[] args)
+        public static void Main()
         {
             var container = new Container();
             var dependencyResolver = new SimpleInjectorDependencyResolver(container);
@@ -52,8 +52,7 @@ namespace _05_SpeedTest
                 .Build();
 
 
-            using (var connection = new TapetiConnection(config))
+            await using var connection = new TapetiConnection(config);
-            {
             var subscriber = await connection.Subscribe(false);
 
 
@@ -80,7 +79,6 @@ namespace _05_SpeedTest
             stopwatch.Stop();
             Console.WriteLine($"Took {stopwatch.ElapsedMilliseconds} ms, {MessageCount / (stopwatch.ElapsedMilliseconds / 1000F):F0} messages/sec");
         }
-        }
 
 
         internal static async Task PublishMessages(IPublisher publisher)

Examples/05-SpeedTest/SpeedMessageController.cs

@@ -15,9 +15,11 @@ namespace _05_SpeedTest
         }
 
 
+        #pragma warning disable IDE0060 // Remove unused parameter
         public void HandleSpeedTestMessage(SpeedTestMessage message)
         {
             messageCounter.Add();
         }
+        #pragma warning restore IDE0060
     }
 }

Examples/06-StatelessRequestResponse/06-StatelessRequestResponse.csproj

@@ -2,12 +2,13 @@
 
   <PropertyGroup>
     <OutputType>Exe</OutputType>
-    <TargetFramework>net5.0</TargetFramework>
+    <TargetFramework>net6.0</TargetFramework>
     <RootNamespace>_06_StatelessRequestResponse</RootNamespace>
+    <Nullable>enable</Nullable>
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="SimpleInjector" Version="5.3.0" />
+    <PackageReference Include="SimpleInjector" Version="5.4.1" />
   </ItemGroup>
 
   <ItemGroup>

Examples/06-StatelessRequestResponse/Program.cs

@@ -12,7 +12,7 @@ namespace _06_StatelessRequestResponse
 {
     public class Program
     {
-        public static void Main(string[] args)
+        public static void Main()
         {
             var container = new Container();
             var dependencyResolver = new SimpleInjectorDependencyResolver(container);
@@ -32,8 +32,7 @@ namespace _06_StatelessRequestResponse
                 .Build();
 
 
-            using (var connection = new TapetiConnection(config))
+            await using var connection = new TapetiConnection(config);
-            {
             await connection.Subscribe();
 
             var publisher = dependencyResolver.Resolve<IPublisher>();
@@ -47,5 +46,4 @@ namespace _06_StatelessRequestResponse
             await waitForDone();
         }
     }
-    }
 }

Examples/06-StatelessRequestResponse/ReceivingMessageController.cs

@@ -8,26 +8,16 @@ namespace _06_StatelessRequestResponse
     public class ReceivingMessageController
     {
         // No publisher required, responses can simply be returned
-        public QuoteResponseMessage HandleQuoteRequest(QuoteRequestMessage message)
+        public static QuoteResponseMessage HandleQuoteRequest(QuoteRequestMessage message)
         {
-            string quote;
+            var quote = message.Amount switch
-
-            switch (message.Amount)
             {
-                case 1:
+                1 =>
                     // Well, they asked for it... :-)
-                    quote = "'";
+                    "'",
-                    break;
+                2 => "\"",
-                
+                _ => null
-                case 2:
+            };
-                    quote = "\"";
-                    break;
-
-                default:
-                    // We have to return a response.
-                    quote = null;
-                    break;
-            }
 
             return new QuoteResponseMessage
             {

Examples/07-ParallelizationTest/07-ParallelizationTest.csproj

@@ -2,12 +2,13 @@
 
   <PropertyGroup>
     <OutputType>Exe</OutputType>
-    <TargetFramework>net5.0</TargetFramework>
+    <TargetFramework>net6.0</TargetFramework>
     <RootNamespace>_07_ParallelizationTest</RootNamespace>
+    <Nullable>enable</Nullable>
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="SimpleInjector" Version="5.3.0" />
+    <PackageReference Include="SimpleInjector" Version="5.4.1" />
   </ItemGroup>
 
   <ItemGroup>

Examples/07-ParallelizationTest/ParallelizationMessageController.cs

@@ -16,9 +16,11 @@ namespace _07_ParallelizationTest
         }
 
 
+        #pragma warning disable IDE0060 // Remove unused parameter
         public async Task HandleSpeedTestMessage(SpeedTestMessage message)
         {
             await messageParallelization.WaitForBatch();
         }
+        #pragma warning restore IDE0060
     }
 }

Examples/07-ParallelizationTest/Program.cs

@@ -105,9 +105,9 @@ namespace _07_ParallelizationTest
         private readonly Func<bool> done;
         private readonly Action<int> timeout;
         private int count;
-        private readonly object waitLock = new object();
+        private readonly object waitLock = new();
-        private TaskCompletionSource<bool> batchReachedTask = new TaskCompletionSource<bool>();
+        private TaskCompletionSource<bool> batchReachedTask = new();
-        private Timer messageExpectedTimer;
+        private Timer? messageExpectedTimer;
         private readonly TimeSpan messageExpectedTimeout = TimeSpan.FromMilliseconds(5000);
 
 
@@ -124,7 +124,7 @@ namespace _07_ParallelizationTest
             lock (waitLock)
             {
                 if (messageExpectedTimer == null)
-                    messageExpectedTimer = new Timer(state =>
+                    messageExpectedTimer = new Timer(_ =>
                     {
                         timeout(count);
                     }, null, messageExpectedTimeout, Timeout.InfiniteTimeSpan);

Examples/08-MessageHandlerLogging/08-MessageHandlerLogging.csproj

@@ -2,13 +2,14 @@
 
   <PropertyGroup>
     <OutputType>Exe</OutputType>
-    <TargetFramework>net5.0</TargetFramework>
+    <TargetFramework>net6.0</TargetFramework>
     <RootNamespace>_08_MessageHandlerLogging</RootNamespace>
+    <Nullable>enable</Nullable>
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="Serilog.Sinks.Console" Version="4.0.0" />
+    <PackageReference Include="Serilog.Sinks.Console" Version="4.1.0" />
-    <PackageReference Include="SimpleInjector" Version="5.3.0" />
+    <PackageReference Include="SimpleInjector" Version="5.4.1" />
   </ItemGroup>
 
   <ItemGroup>

Examples/08-MessageHandlerLogging/Program.cs

@@ -3,7 +3,6 @@ using System.Threading.Tasks;
 using ExampleLib;
 using Messaging.TapetiExample;
 using Serilog;
-using Serilog.Events;
 using SimpleInjector;
 using Tapeti;
 using Tapeti.Serilog;

Examples/ExampleLib/ExampleConsoleApp.cs

@@ -24,7 +24,7 @@ namespace ExampleLib
         private readonly IDependencyContainer dependencyResolver;
         private readonly int expectedDoneCount;
         private int doneCount;
-        private readonly TaskCompletionSource<bool> doneSignal = new TaskCompletionSource<bool>();
+        private readonly TaskCompletionSource<bool> doneSignal = new();
 
 
         /// <param name="dependencyResolver">Uses Tapeti's IDependencyContainer interface so you can easily switch an example to your favourite IoC container</param>
@@ -79,7 +79,7 @@ namespace ExampleLib
         {
             while (true)
             {
-                if (!(e is AggregateException aggregateException)) 
+                if (e is not AggregateException aggregateException) 
                     return e;
 
                 if (aggregateException.InnerExceptions.Count != 1)

Examples/ExampleLib/ExampleLib.csproj

@@ -1,8 +1,9 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFramework>netstandard2.0</TargetFramework>
+    <TargetFramework>net6.0</TargetFramework>
     <GenerateDocumentationFile>true</GenerateDocumentationFile>
+    <Nullable>enable</Nullable>
   </PropertyGroup>
 
   <ItemGroup>

Examples/Messaging.TapetiExample/Messaging.TapetiExample.csproj

@@ -6,7 +6,7 @@
 
   <ItemGroup>
     <PackageReference Include="System.ComponentModel.Annotations" Version="5.0.0" />
-    <PackageReference Include="Tapeti.Annotations" Version="3.0.0" />
+    <PackageReference Include="Tapeti.Annotations" Version="3.*-*" />
   </ItemGroup>
 
 </Project>

Tapeti.Autofac/AutofacDependencyResolver.cs

@@ -1,10 +1,12 @@
 using System;
+using System.Diagnostics.CodeAnalysis;
 using Autofac;
 using Autofac.Builder;
 
+// ReSharper disable UnusedMember.Global
+
 namespace Tapeti.Autofac
 {
-    /// <inheritdoc />
     /// <summary>
     /// Dependency resolver and container implementation for Autofac.
     /// Since this class needs access to both the ContainerBuilder and the built IContainer,
@@ -13,21 +15,20 @@ namespace Tapeti.Autofac
     /// </summary>
     public class AutofacDependencyResolver : IDependencyContainer
     {
-        private ContainerBuilder containerBuilder;
+        private ContainerBuilder? containerBuilder;
-        private IContainer container;
+        private IContainer? container;
 
 
         /// <summary>
-        /// The built container. Either set directly, or use the Build method to built the
+        /// The built container. Either set directly, or use the Build method to build the
         /// update this reference.
         /// </summary>
         public IContainer Container
         {
-            get => container;
+            get => container ?? throw new ArgumentNullException(nameof(container));
             set
             {
                 container = value;
-                if (value != null)
                 containerBuilder = null;
             }
         }
@@ -49,7 +50,7 @@ namespace Tapeti.Autofac
             CheckContainerBuilder();
             Container = containerBuilder.Build(options);
 
-            return container;
+            return Container;
         }
 
 
@@ -83,7 +84,7 @@ namespace Tapeti.Autofac
         {
             CheckContainerBuilder();
             containerBuilder
-                .Register(context => factory())
+                .Register(_ => factory())
                 .As<TService>()
                 .PreserveExistingDefaults();
         }
@@ -116,7 +117,7 @@ namespace Tapeti.Autofac
         {
             CheckContainerBuilder();
             containerBuilder
-                .Register(context => factory())
+                .Register(_ => factory())
                 .As<TService>()
                 .SingleInstance()
                 .PreserveExistingDefaults();
@@ -140,6 +141,7 @@ namespace Tapeti.Autofac
         }
 
 
+        [MemberNotNull(nameof(containerBuilder))]
         private void CheckContainerBuilder()
         {
             if (containerBuilder == null)

Tapeti.Autofac/Tapeti.Autofac.csproj

@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFramework>netstandard2.0</TargetFramework>
+    <TargetFrameworks>net6.0;net7.0</TargetFrameworks>
     <GenerateDocumentationFile>true</GenerateDocumentationFile>
     <Authors>Mark van Renswoude</Authors>
     <Company />
@@ -11,10 +11,12 @@
     <PackageProjectUrl>https://github.com/MvRens/Tapeti</PackageProjectUrl>
     <PackageIcon>Tapeti.SimpleInjector.png</PackageIcon>
     <Version>2.0.0</Version>
+    <LangVersion>9</LangVersion>
+    <Nullable>enable</Nullable>
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="Autofac" Version="6.2.0" />
+    <PackageReference Include="Autofac" Version="6.*" />
   </ItemGroup>
 
   <ItemGroup>
@@ -29,6 +31,6 @@
   </ItemGroup>
 
   <ItemGroup>
-    <PackageReference Include="Microsoft.SourceLink.GitHub" Version="1.0.0" PrivateAssets="All"/>
+    <PackageReference Include="Microsoft.SourceLink.GitHub" Version="1.1.1" PrivateAssets="All" />
   </ItemGroup>
 </Project>

Tapeti.Benchmarks/Program.cs

@@ -0,0 +1,5 @@
+using BenchmarkDotNet.Running;
+using Tapeti.Benchmarks.Tests;
+
+BenchmarkRunner.Run<MethodInvokeBenchmarks>();
+//new MethodInvokeBenchmarks().InvokeExpressionValueFactory();

Tapeti.Benchmarks/Tapeti.Benchmarks.csproj

@@ -0,0 +1,18 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <TargetFramework>net6.0</TargetFramework>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="BenchmarkDotNet" Version="0.13.2" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\Tapeti\Tapeti.csproj" />
+  </ItemGroup>
+
+</Project>

Tapeti.Benchmarks/Tests/MethodInvokeBenchmarks.cs

@@ -0,0 +1,112 @@
+using System.Reflection;
+using BenchmarkDotNet.Attributes;
+using Tapeti.Helpers;
+
+#pragma warning disable CA1822 // Mark members as static - required for Benchmark.NET
+
+namespace Tapeti.Benchmarks.Tests
+{
+    [MemoryDiagnoser]
+    public class MethodInvokeBenchmarks
+    {
+        private delegate bool MethodToInvokeDelegate(object obj);
+
+        private static readonly MethodInfo MethodToInvokeInfo;
+        private static readonly MethodToInvokeDelegate MethodToInvokeDelegateInstance;
+        private static readonly ExpressionInvoke MethodToInvokeExpression;
+
+
+        static MethodInvokeBenchmarks()
+        {
+            MethodToInvokeInfo = typeof(MethodInvokeBenchmarks).GetMethod(nameof(MethodToInvoke))!;
+
+            var inputInstance = new MethodInvokeBenchmarks();
+            MethodToInvokeDelegateInstance = i => ((MethodInvokeBenchmarks)i).MethodToInvoke(inputInstance.GetSomeObject(), inputInstance.GetCancellationToken());
+            MethodToInvokeExpression = MethodToInvokeInfo.CreateExpressionInvoke();
+
+            /*
+
+            Fun experiment, but a bit too tricky for me at the moment.
+
+
+            var dynamicMethodToInvoke = new DynamicMethod(
+                nameof(MethodToInvoke),
+                typeof(bool),
+                new[] { typeof(object) },
+                typeof(MethodInvokeBenchmarks).Module);
+
+
+            var generator = dynamicMethodToInvoke.GetILGenerator(256);
+
+            generator.Emit(OpCodes.Ldarg_0); // Load the first argument (the instance) onto the stack
+            generator.Emit(OpCodes.Castclass, typeof(MethodInvokeBenchmarks)); // Cast to the expected instance type 
+            generator.Emit(OpCodes.Ldc_I4_S, 42); // Push the first argument onto the stack
+            generator.EmitCall(OpCodes.Callvirt, MethodToInvokeInfo, null); // Call the method
+            generator.Emit(OpCodes.Ret);
+
+            MethodToInvokeEmitted = dynamicMethodToInvoke.CreateDelegate<MethodToInvokeDelegate>();
+            */
+        }
+
+
+        public bool MethodToInvoke(object someObject, CancellationToken cancellationToken)
+        {
+            return true;
+        }
+
+
+        // ReSharper disable MemberCanBeMadeStatic.Local
+        private object GetSomeObject()
+        {
+            return new object();
+        }
+
+
+        private CancellationToken GetCancellationToken()
+        {
+            return CancellationToken.None;
+        }
+        // ReSharper restore MemberCanBeMadeStatic.Local
+
+
+
+        // For comparison
+        [Benchmark]
+        public bool Direct()
+        {
+            return MethodToInvoke(GetSomeObject(), GetCancellationToken());
+        }
+
+
+        // For comparison as well, as we don't know the signature beforehand
+        [Benchmark]
+        public bool Delegate()
+        {
+            var instance = new MethodInvokeBenchmarks();
+            return MethodToInvokeDelegateInstance(instance);
+        }
+
+
+        [Benchmark]
+        public bool MethodInvoke()
+        {
+            var instance = new MethodInvokeBenchmarks();
+            return (bool)(MethodToInvokeInfo.Invoke(instance, BindingFlags.DoNotWrapExceptions, null, new[] { GetSomeObject(), GetCancellationToken() }, null) ?? false);
+        }
+
+
+        [Benchmark]
+        public bool InvokeExpression()
+        {
+            var instance = new MethodInvokeBenchmarks();
+            return (bool)MethodToInvokeExpression(instance, GetSomeObject(), GetCancellationToken());
+        }
+
+        //[Benchmark]
+        //public bool ReflectionEmit()
+        //{
+        //    var instance = new MethodInvokeBenchmarks();
+        //    return MethodToInvokeEmitted(instance);
+        //}
+    }
+}

Tapeti.CastleWindsor/Tapeti.CastleWindsor.csproj

@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFramework>netstandard2.0</TargetFramework>
+    <TargetFrameworks>net6.0;net7.0</TargetFrameworks>
     <GenerateDocumentationFile>true</GenerateDocumentationFile>
     <Authors>Mark van Renswoude</Authors>
     <Company />
@@ -11,10 +11,12 @@
     <PackageProjectUrl>https://github.com/MvRens/Tapeti</PackageProjectUrl>
     <PackageIcon>Tapeti.SimpleInjector.png</PackageIcon>
     <Version>2.0.0</Version>
+    <LangVersion>9</LangVersion>
+    <Nullable>enable</Nullable>
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="Castle.Windsor" Version="5.1.1" />
+    <PackageReference Include="Castle.Windsor" Version="5.*" />
   </ItemGroup>
 
   <ItemGroup>
@@ -29,6 +31,6 @@
   </ItemGroup>
 
   <ItemGroup>
-    <PackageReference Include="Microsoft.SourceLink.GitHub" Version="1.0.0" PrivateAssets="All"/>
+    <PackageReference Include="Microsoft.SourceLink.GitHub" Version="1.1.1" PrivateAssets="All" />
   </ItemGroup>
 </Project>

Tapeti.CastleWindsor/WindsorDependencyResolver.cs

@@ -4,7 +4,6 @@ using Castle.Windsor;
 
 namespace Tapeti.CastleWindsor
 {
-    /// <inheritdoc />
     /// <summary>
     /// Dependency resolver and container implementation for Castle Windsor.
     /// </summary>

Tapeti.DataAnnotations/DataAnnotationsExtension.cs

@@ -3,7 +3,6 @@ using Tapeti.Config;
 
 namespace Tapeti.DataAnnotations
 {
-    /// <inheritdoc />
     /// <summary>
     /// Provides the DataAnnotations validation middleware.
     /// </summary>

Tapeti.DataAnnotations/DataAnnotationsMessageMiddleware.cs

@@ -5,19 +5,21 @@ using Tapeti.Config;
 
 namespace Tapeti.DataAnnotations
 {
-    /// <inheritdoc />
     /// <summary>
     /// Validates consumed messages using System.ComponentModel.DataAnnotations
     /// </summary>
     internal class DataAnnotationsMessageMiddleware : IMessageMiddleware
     {
         /// <inheritdoc />
-        public async Task Handle(IMessageContext context, Func<Task> next)
+        public ValueTask Handle(IMessageContext context, Func<ValueTask> next)
         {
+            if (context.Message == null) 
+                return next();
+
             var validationContext = new ValidationContext(context.Message);
             Validator.ValidateObject(context.Message, validationContext, true);
 
-            await next();
+            return next();
         }
     }
 }

Tapeti.DataAnnotations/DataAnnotationsPublishMiddleware.cs

@@ -5,19 +5,18 @@ using Tapeti.Config;
 
 namespace Tapeti.DataAnnotations
 {
-    /// <inheritdoc />
     /// <summary>
     /// Validates published messages using System.ComponentModel.DataAnnotations
     /// </summary>
     internal class DataAnnotationsPublishMiddleware : IPublishMiddleware
     {
         /// <inheritdoc />
-        public async Task Handle(IPublishContext context, Func<Task> next)
+        public ValueTask Handle(IPublishContext context, Func<ValueTask> next)
         {
             var validationContext = new ValidationContext(context.Message);
             Validator.ValidateObject(context.Message, validationContext, true);
 
-            await next();
+            return next();
         }
     }
 }

Tapeti.DataAnnotations/Tapeti.DataAnnotations.csproj

@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFramework>netstandard2.0</TargetFramework>
+    <TargetFrameworks>net6.0;net7.0</TargetFrameworks>
     <GenerateDocumentationFile>true</GenerateDocumentationFile>
     <Authors>Mark van Renswoude</Authors>
     <Company />
@@ -11,6 +11,8 @@
     <PackageProjectUrl>https://github.com/MvRens/Tapeti</PackageProjectUrl>
     <PackageIcon>Tapeti.DataAnnotations.png</PackageIcon>
     <Version>2.0.0</Version>
+    <LangVersion>9</LangVersion>
+    <Nullable>enable</Nullable>
   </PropertyGroup>
 
   <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug|AnyCPU'">
@@ -33,6 +35,6 @@
   </ItemGroup>
 
   <ItemGroup>
-    <PackageReference Include="Microsoft.SourceLink.GitHub" Version="1.0.0" PrivateAssets="All"/>
+    <PackageReference Include="Microsoft.SourceLink.GitHub" Version="1.1.1" PrivateAssets="All" />
   </ItemGroup>
 </Project>

Tapeti.Flow.SQL/ConfigExtensions.cs

@@ -1,4 +1,5 @@
 using System.Collections.Generic;
+using System.Linq;
 using Tapeti.Config;
 
 // ReSharper disable UnusedMember.Global
@@ -45,7 +46,7 @@ namespace Tapeti.Flow.SQL
 
         public IEnumerable<object> GetMiddleware(IDependencyResolver dependencyResolver)
         {
-            return null;
+            return Enumerable.Empty<object>();
         }
     }
 }

Tapeti.Flow.SQL/SqlConnectionFlowRepository.cs

@@ -5,9 +5,12 @@ using System.Data.SqlClient;
 using System.Threading.Tasks;
 using Newtonsoft.Json;
 
+// Neither of these are available in language version 7 required for .NET Standard 2.0
+// ReSharper disable ConvertToUsingDeclaration
+// ReSharper disable UseAwaitUsing
+
 namespace Tapeti.Flow.SQL
 {
-    /// <inheritdoc />
     /// <summary>
     /// IFlowRepository implementation for SQL server.
     /// </summary>
@@ -37,7 +40,7 @@ namespace Tapeti.Flow.SQL
 
 
         /// <inheritdoc />
-        public async Task<IEnumerable<FlowRecord<T>>> GetStates<T>()
+        public async ValueTask<IEnumerable<FlowRecord<T>>> GetStates<T>()
         {
             return await SqlRetryHelper.Execute(async () =>
             {
@@ -55,6 +58,7 @@ namespace Tapeti.Flow.SQL
                         var stateJson = flowReader.GetString(2);
 
                         var state = JsonConvert.DeserializeObject<T>(stateJson);
+                        if (state != null)
                             result.Add(new FlowRecord<T>(flowID, creationTime, state));
                     }
 
@@ -64,7 +68,7 @@ namespace Tapeti.Flow.SQL
         }
 
         /// <inheritdoc />
-        public async Task CreateState<T>(Guid flowID, T state, DateTime timestamp)
+        public async ValueTask CreateState<T>(Guid flowID, T state, DateTime timestamp)
         {
             await SqlRetryHelper.Execute(async () =>
             {
@@ -88,7 +92,7 @@ namespace Tapeti.Flow.SQL
         }
 
         /// <inheritdoc />
-        public async Task UpdateState<T>(Guid flowID, T state)
+        public async ValueTask UpdateState<T>(Guid flowID, T state)
         {
             await SqlRetryHelper.Execute(async () =>
             {
@@ -108,7 +112,7 @@ namespace Tapeti.Flow.SQL
         }
 
         /// <inheritdoc />
-        public async Task DeleteState(Guid flowID)
+        public async ValueTask DeleteState(Guid flowID)
         {
             await SqlRetryHelper.Execute(async () =>
             {

Tapeti.Flow.SQL/SqlExceptionHelper.cs

@@ -13,7 +13,7 @@ namespace Tapeti.Flow.SQL
         // 2627: Violation of %ls constraint '%.*ls'. Cannot insert duplicate key in object '%.*ls'. The duplicate key value is %ls.
         public static bool IsDuplicateKey(SqlException e)
         {
-            return e != null && (e.Number == 2601 || e.Number == 2627);
+            return e is { Number: 2601 or 2627 };
         }
 
 
@@ -21,12 +21,12 @@ namespace Tapeti.Flow.SQL
         {
             switch (e)
             {
-                case TimeoutException _:
+                case TimeoutException:
                     return true;
 
-                case Exception exception:
+                case not null:
                     {
-                        var sqlExceptions = ExtractSqlExceptions(exception);
+                        var sqlExceptions = ExtractSqlExceptions(e);
                         return sqlExceptions.Select(UnwrapSqlErrors).Any(IsRecoverableSQLError);
                     }
 
@@ -38,11 +38,13 @@ namespace Tapeti.Flow.SQL
         /// <summary>
         /// Extracts alls SqlExceptions from the main and inner or aggregate exceptions
         /// </summary>
-        public static IEnumerable<SqlException> ExtractSqlExceptions(Exception e)
+        public static IEnumerable<SqlException> ExtractSqlExceptions(Exception exception)
         {
-            while (e != null)
+            var exceptionHead = exception;
+
+            while (exceptionHead != null)
             {
-                switch (e)
+                switch (exceptionHead)
                 {
                     case AggregateException aggregateException:
                         foreach (var innerException in aggregateException.InnerExceptions)
@@ -56,7 +58,8 @@ namespace Tapeti.Flow.SQL
                         yield return sqlException;
                         break;
                 }
-                e = e.InnerException;
+
+                exceptionHead = exceptionHead.InnerException;
             }
         }
 
@@ -66,12 +69,14 @@ namespace Tapeti.Flow.SQL
         /// </summary>
         public static IEnumerable<SqlError> UnwrapSqlErrors(SqlException exception)
         {
-            while (exception != null)
+            var exceptionHead = exception;
+
+            while (exceptionHead != null)
             {
-                foreach (SqlError error in exception.Errors)
+                foreach (SqlError error in exceptionHead.Errors)
                     yield return error;
 
-                exception = exception.InnerException as SqlException;
+                exceptionHead = exceptionHead.InnerException as SqlException;
             }
         }
 

Tapeti.Flow.SQL/SqlRetryHelper.cs

@@ -54,7 +54,7 @@ namespace Tapeti.Flow.SQL
                 returnValue = await callback();
             });
 
-            return returnValue;
+            return returnValue!;
         }
     }
 }

Tapeti.Flow.SQL/Tapeti.Flow.SQL.csproj

@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFramework>netstandard2.0</TargetFramework>
+    <TargetFrameworks>net6.0;net7.0</TargetFrameworks>
     <GenerateDocumentationFile>true</GenerateDocumentationFile>
     <Authors>Mark van Renswoude</Authors>
     <Company />
@@ -11,12 +11,19 @@
     <PackageProjectUrl>https://github.com/MvRens/Tapeti</PackageProjectUrl>
     <PackageIcon>Tapeti.Flow.SQL.png</PackageIcon>
     <Version>2.0.0</Version>
+    <LangVersion>9</LangVersion>
+    <Nullable>enable</Nullable>
   </PropertyGroup>
 
   <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug|AnyCPU'">
     <NoWarn>1701;1702</NoWarn>
   </PropertyGroup>
 
+  <PropertyGroup Condition="'$(TargetFramework)'!='netstandard2.0'">
+    <!-- Suppress 'using statement can be simplified' which requires language version 8 not available in .NET Standard 2.0 -->
+    <NoWarn>IDE0063</NoWarn>
+  </PropertyGroup>
+
   <ItemGroup>
     <None Remove="scripts\Flow table.sql" />
   </ItemGroup>
@@ -26,7 +33,7 @@
   </ItemGroup>
 
   <ItemGroup>
-    <PackageReference Include="System.Data.SqlClient" Version="4.8.2" />
+    <PackageReference Include="System.Data.SqlClient" Version="4.8.5" />
   </ItemGroup>
 
   <ItemGroup>
@@ -42,6 +49,6 @@
   </ItemGroup>
 
   <ItemGroup>
-    <PackageReference Include="Microsoft.SourceLink.GitHub" Version="1.0.0" PrivateAssets="All"/>
+    <PackageReference Include="Microsoft.SourceLink.GitHub" Version="1.1.1" PrivateAssets="All" />
   </ItemGroup>
 </Project>

Tapeti.Flow/Annotations/ContinuationAttribute.cs

@@ -2,7 +2,6 @@
 
 namespace Tapeti.Flow.Annotations
 {
-    /// <inheritdoc />
     /// <summary>
     /// Marks a message handler as a response message handler which continues a Tapeti Flow.
     /// The method only receives direct messages, and does not create a routing key based binding to the queue.

Tapeti.Flow/Annotations/StartAttribute.cs

@@ -3,7 +3,6 @@ using JetBrains.Annotations;
 
 namespace Tapeti.Flow.Annotations
 {
-    /// <inheritdoc />
     /// <summary>
     /// Marks this method as the start of a Tapeti Flow. Use IFlowStarter.Start to begin a new flow and
     /// call this method. Must return an IYieldPoint.

Tapeti.Flow/ConfigExtensions.cs

@@ -1,5 +1,7 @@
 using Tapeti.Config;
 
+// ReSharper disable UnusedMember.Global
+
 namespace Tapeti.Flow
 {
     /// <summary>
@@ -13,7 +15,7 @@ namespace Tapeti.Flow
         /// <param name="config"></param>
         /// <param name="flowRepository">An optional IFlowRepository implementation to persist flow state. If not provided, flow state will be lost when the application restarts.</param>
         /// <returns></returns>
-        public static ITapetiConfigBuilder WithFlow(this ITapetiConfigBuilder config, IFlowRepository flowRepository = null)
+        public static ITapetiConfigBuilder WithFlow(this ITapetiConfigBuilder config, IFlowRepository? flowRepository = null)
         {
             config.Use(new FlowExtension(flowRepository));
             return config;

Tapeti.Flow/Default/FlowBindingMiddleware.cs

@@ -1,4 +1,5 @@
 using System;
+using System.Diagnostics;
 using System.Linq;
 using System.Reflection;
 using System.Threading.Tasks;
@@ -9,6 +10,17 @@ using Tapeti.Helpers;
 
 namespace Tapeti.Flow.Default
 {
+    #if !NET7_0_OR_GREATER
+    #pragma warning disable CS1591
+    public class UnreachableException : Exception
+    {
+        public UnreachableException(string message) : base(message)
+        {
+        }
+    }
+    #pragma warning restore CS1591
+    #endif
+
     internal class FlowBindingMiddleware : IControllerBindingMiddleware
     {
         public void Handle(IControllerBindingContext context, Action next)
@@ -31,6 +43,9 @@ namespace Tapeti.Flow.Default
             if (continuationAttribute == null)
                 return;
 
+            if (context.Method.IsStatic)
+                throw new ArgumentException($"Continuation attribute is not valid on static methods in controller {context.Method.DeclaringType?.FullName}, method {context.Method.Name}");
+
             context.SetBindingTargetMode(BindingTargetMode.Direct);
             context.Use(new FlowContinuationMiddleware());
 
@@ -43,16 +58,31 @@ namespace Tapeti.Flow.Default
             {
                 context.Result.SetHandler(async (messageContext, value) =>
                 {
+                    if (value == null)
+                        throw new InvalidOperationException("Return value should be a Task, not null");
+
                     await (Task)value;
                     await HandleParallelResponse(messageContext);
                 });
             }
+            if (context.Result.Info.ParameterType == typeof(ValueTask))
+            {
+                context.Result.SetHandler(async (messageContext, value) =>
+                {
+                    if (value == null)
+                        // ValueTask is a struct and should never be null
+                        throw new UnreachableException("Return value should be a ValueTask, not null");
+
+                    await (ValueTask)value;
+                    await HandleParallelResponse(messageContext);
+                });
+            }
             else if (context.Result.Info.ParameterType == typeof(void))
             {
-                context.Result.SetHandler((messageContext, value) => HandleParallelResponse(messageContext));
+                context.Result.SetHandler((messageContext, _) => HandleParallelResponse(messageContext));
             }
             else
-                throw new ArgumentException($"Result type must be IYieldPoint, Task or void in controller {context. Method.DeclaringType?.FullName}, method {context.Method.Name}");
+                throw new ArgumentException($"Result type must be IYieldPoint, Task or void in controller {context.Method.DeclaringType?.FullName}, method {context.Method.Name}");
 
 
             foreach (var parameter in context.Parameters.Where(p => !p.HasBinding && p.Info.ParameterType == typeof(IFlowParallelRequest)))
@@ -62,34 +92,64 @@ namespace Tapeti.Flow.Default
 
         private static void RegisterYieldPointResult(IControllerBindingContext context)
         {
-            if (!context.Result.Info.ParameterType.IsTypeOrTaskOf(typeof(IYieldPoint), out var isTaskOf))
+            if (!context.Result.Info.ParameterType.IsTypeOrTaskOf(typeof(IYieldPoint), out var taskType))
                 return;
 
-            if (isTaskOf)
+            if (context.Method.IsStatic)
+                throw new ArgumentException($"Yield points are not valid on static methods in controller {context.Method.DeclaringType?.FullName}, method {context.Method.Name}");
+
+            switch (taskType)
             {
+                case TaskType.None:
+                    context.Result.SetHandler((messageContext, value) =>
+                    {
+                        if (value == null)
+                            throw new InvalidOperationException("Return value should be an IYieldPoint, not null");
+
+                        return HandleYieldPoint(messageContext, (IYieldPoint)value);
+                    });
+                    break;
+
+                case TaskType.Task:
                     context.Result.SetHandler(async (messageContext, value) =>
                     {
+                        if (value == null)
+                            throw new InvalidOperationException("Return value should be a Task<IYieldPoint>, not null");
+
                         var yieldPoint = await (Task<IYieldPoint>)value;
-                    if (yieldPoint != null)
                         await HandleYieldPoint(messageContext, yieldPoint);
                     });
+                    break;
+
+                case TaskType.ValueTask:
+                    context.Result.SetHandler(async (messageContext, value) =>
+                    {
+                        if (value == null)
+                            // ValueTask is a struct and should never be null
+                            throw new UnreachableException("Return value should be a ValueTask<IYieldPoint>, not null");
+
+                        var yieldPoint = await (ValueTask<IYieldPoint>)value;
+                        await HandleYieldPoint(messageContext, yieldPoint);
+                    });
+                    break;
+
+                default:
+                    throw new ArgumentOutOfRangeException();
             }
-            else
-                context.Result.SetHandler((messageContext, value) => HandleYieldPoint(messageContext, (IYieldPoint)value));
         }
 
 
-        private static Task HandleYieldPoint(IMessageContext context, IYieldPoint yieldPoint)
+        private static ValueTask HandleYieldPoint(IMessageContext context, IYieldPoint yieldPoint)
         {
             var flowHandler = context.Config.DependencyResolver.Resolve<IFlowHandler>();
             return flowHandler.Execute(new FlowHandlerContext(context), yieldPoint);
         }
 
 
-        private static Task HandleParallelResponse(IMessageContext context)
+        private static ValueTask HandleParallelResponse(IMessageContext context)
         {
             if (context.TryGet<FlowMessageContextPayload>(out var flowPayload) && flowPayload.FlowIsConverging)
-                return Task.CompletedTask;
+                return default;
 
             var flowHandler = context.Config.DependencyResolver.Resolve<IFlowHandler>();
             return flowHandler.Execute(new FlowHandlerContext(context), new DelegateYieldPoint(async flowContext =>
@@ -110,7 +170,7 @@ namespace Tapeti.Flow.Default
         }
 
 
-        private static object ParallelRequestParameterFactory(IMessageContext context)
+        private static object? ParallelRequestParameterFactory(IMessageContext context)
         {
             var flowHandler = context.Config.DependencyResolver.Resolve<IFlowHandler>();
             return flowHandler.GetParallelRequest(new FlowHandlerContext(context));

Tapeti.Flow/Default/FlowContext.cs

@@ -6,35 +6,57 @@ namespace Tapeti.Flow.Default
 {
     internal class FlowContext : IDisposable
     {
-        public IFlowHandlerContext HandlerContext { get; set; }
+        private readonly IFlowHandlerContext? handlerContext;
-        public IFlowStateLock FlowStateLock { get; set; }
+        private IFlowStateLock? flowStateLock;
-        public FlowState FlowState { get; set; }
+        private FlowState? flowState;
+
+
+        public IFlowHandlerContext HandlerContext => handlerContext ?? throw new InvalidOperationException("FlowContext does not have a HandlerContext");
+        public IFlowStateLock FlowStateLock => flowStateLock ?? throw new InvalidOperationException("FlowContext does not have a FlowStateLock");
+        public FlowState FlowState => flowState ?? throw new InvalidOperationException("FlowContext does not have a FlowState");
+
+        public bool HasFlowStateAndLock => flowState != null && flowStateLock != null;
 
         public Guid ContinuationID { get; set; }
-        public ContinuationMetadata ContinuationMetadata { get; set; }
+        public ContinuationMetadata? ContinuationMetadata { get; set; }
 
         private int storeCalled;
         private int deleteCalled;
 
 
-        public async Task Store(bool persistent)
+        public FlowContext(IFlowHandlerContext handlerContext, FlowState flowState, IFlowStateLock flowStateLock)
+        {
+            this.flowState = flowState;
+            this.flowStateLock = flowStateLock;
+            this.handlerContext = handlerContext;
+        }
+
+
+        public FlowContext(IFlowHandlerContext handlerContext)
+        {
+            this.handlerContext = handlerContext;
+        }
+
+
+        public void SetFlowState(FlowState newFlowState, IFlowStateLock newFlowStateLock)
+        {
+            flowState = newFlowState;
+            flowStateLock = newFlowStateLock;
+        }
+
+
+        public ValueTask Store(bool persistent)
         {
             storeCalled++;
 
-            if (HandlerContext == null) throw new ArgumentNullException(nameof(HandlerContext));
-            if (FlowState == null) throw new ArgumentNullException(nameof(FlowState));
-            if (FlowStateLock == null) throw new ArgumentNullException(nameof(FlowStateLock));
-
             FlowState.Data = Newtonsoft.Json.JsonConvert.SerializeObject(HandlerContext.Controller);
-            await FlowStateLock.StoreFlowState(FlowState, persistent);
+            return FlowStateLock.StoreFlowState(FlowState, persistent);
         }
 
-        public async Task Delete()
+        public ValueTask Delete()
         {
             deleteCalled++;
-
+            return flowStateLock?.DeleteFlowState() ?? default;
-            if (FlowStateLock != null)
-                await FlowStateLock.DeleteFlowState();
         }
 
         public bool IsStoredOrDeleted()
@@ -45,7 +67,7 @@ namespace Tapeti.Flow.Default
         public void EnsureStoreOrDeleteIsCalled()
         {
             if (!IsStoredOrDeleted())
-                throw new InvalidProgramException("Neither Store nor Delete are called for the state of the current flow. FlowID = " + FlowStateLock?.FlowID);
+                throw new InvalidProgramException("Neither Store nor Delete are called for the state of the current flow. FlowID = " + flowStateLock?.FlowID);
 
             Debug.Assert(storeCalled <= 1, "Store called more than once!");
             Debug.Assert(deleteCalled <= 1, "Delete called more than once!");
@@ -53,7 +75,7 @@ namespace Tapeti.Flow.Default
 
         public void Dispose()
         {
-            FlowStateLock?.Dispose();
+            flowStateLock?.Dispose();
         }
     }
 }

Tapeti.Flow/Default/FlowContinuationMiddleware.cs

@@ -1,5 +1,4 @@
 using System;
-using System.Reflection;
 using System.Threading.Tasks;
 using Tapeti.Config;
 using Tapeti.Flow.FlowHelpers;
@@ -12,7 +11,7 @@ namespace Tapeti.Flow.Default
     /// </summary>
     internal class FlowContinuationMiddleware : IControllerFilterMiddleware, IControllerMessageMiddleware, IControllerCleanupMiddleware
     {
-        public async Task Filter(IMessageContext context, Func<Task> next)
+        public async ValueTask Filter(IMessageContext context, Func<ValueTask> next)
         {
             if (!context.TryGet<ControllerMessageContextPayload>(out var controllerPayload))
                 return;
@@ -28,14 +27,18 @@ namespace Tapeti.Flow.Default
         }
 
 
-        public async Task Handle(IMessageContext context, Func<Task> next)
+        public async ValueTask Handle(IMessageContext context, Func<ValueTask> next)
         {
             if (!context.TryGet<ControllerMessageContextPayload>(out var controllerPayload))
                 return;
 
             if (context.TryGet<FlowMessageContextPayload>(out var flowPayload))
             {
+                if (controllerPayload.Controller == null)
+                    throw new InvalidOperationException("Controller is not available (method is static?)");
+
                 var flowContext = flowPayload.FlowContext;
+                if (!string.IsNullOrEmpty(flowContext.FlowState.Data))
                     Newtonsoft.Json.JsonConvert.PopulateObject(flowContext.FlowState.Data, controllerPayload.Controller);
 
                 // Remove Continuation now because the IYieldPoint result handler will store the new state
@@ -54,7 +57,7 @@ namespace Tapeti.Flow.Default
         }
 
 
-        public async Task Cleanup(IMessageContext context, ConsumeResult consumeResult, Func<Task> next)
+        public async ValueTask Cleanup(IMessageContext context, ConsumeResult consumeResult, Func<ValueTask> next)
         {
             await next();
 
@@ -66,11 +69,11 @@ namespace Tapeti.Flow.Default
 
             var flowContext = flowPayload.FlowContext;
 
-            if (flowContext.ContinuationMetadata.MethodName != MethodSerializer.Serialize(controllerPayload.Binding.Method))
+            if (flowContext.ContinuationMetadata == null || flowContext.ContinuationMetadata.MethodName != MethodSerializer.Serialize(controllerPayload.Binding.Method))
                 // Do not call when the controller method was filtered, if the same message has two methods
                 return;
 
-            if (flowContext.FlowStateLock != null)
+            if (flowContext.HasFlowStateAndLock)
             {
                 if (!flowContext.IsStoredOrDeleted())
                     // The exception strategy can set the consume result to Success. Instead, check if the yield point
@@ -83,7 +86,7 @@ namespace Tapeti.Flow.Default
 
 
 
-        private static async Task<FlowContext> EnrichWithFlowContext(IMessageContext context)
+        private static async ValueTask<FlowContext?> EnrichWithFlowContext(IMessageContext context)
         {
             if (context.TryGet<FlowMessageContextPayload>(out var flowPayload))
                 return flowPayload.FlowContext;
@@ -107,13 +110,8 @@ namespace Tapeti.Flow.Default
             if (flowState == null)
                 return null;
 
-            var flowContext = new FlowContext
+            var flowContext = new FlowContext(new FlowHandlerContext(context), flowState, flowStateLock)
             {
-                HandlerContext = new FlowHandlerContext(context),
-
-                FlowStateLock = flowStateLock,
-                FlowState = flowState,
-
                 ContinuationID = continuationID,
                 ContinuationMetadata = flowState.Continuations.TryGetValue(continuationID, out var continuation) ? continuation : null
             };

Tapeti.Flow/Default/FlowHandlerContext.cs

@@ -3,7 +3,6 @@ using Tapeti.Config;
 
 namespace Tapeti.Flow.Default
 {
-    /// <inheritdoc />
     /// <summary>
     /// Default implementation for IFlowHandlerContext
     /// </summary>
@@ -11,8 +10,11 @@ namespace Tapeti.Flow.Default
     {
         /// <summary>
         /// </summary>
-        public FlowHandlerContext()
+        public FlowHandlerContext(ITapetiConfig config, object? controller, MethodInfo method)
         {
+            Config = config;
+            Controller = controller;
+            Method = method;
         }
 
 
@@ -20,11 +22,7 @@ namespace Tapeti.Flow.Default
         /// </summary>
         public FlowHandlerContext(IMessageContext source)
         {
-            if (source == null)
+            var controllerPayload = source.Get<ControllerMessageContextPayload>();
-                return;
-
-            if (!source.TryGet<ControllerMessageContextPayload>(out var controllerPayload))
-                return;
 
             Config = source.Config;
             Controller = controllerPayload.Controller;
@@ -39,15 +37,15 @@ namespace Tapeti.Flow.Default
         }
 
         /// <inheritdoc />
-        public ITapetiConfig Config { get; set; }
+        public ITapetiConfig Config { get; }
 
         /// <inheritdoc />
-        public object Controller { get; set; }
+        public object? Controller { get; }
 
         /// <inheritdoc />
-        public MethodInfo Method { get; set; }
+        public MethodInfo Method { get; }
 
         /// <inheritdoc />
-        public IMessageContext MessageContext { get; set; }
+        public IMessageContext? MessageContext { get; }
     }
 }

Tapeti.Flow/Default/FlowProvider.cs

@@ -32,14 +32,21 @@ namespace Tapeti.Flow.Default
 
 
         /// <inheritdoc />
-        public IYieldPoint YieldWithRequest<TRequest, TResponse>(TRequest message, Func<TResponse, Task<IYieldPoint>> responseHandler)
+        public IYieldPoint YieldWithRequest<TRequest, TResponse>(TRequest message, Func<TResponse, Task<IYieldPoint>> responseHandler) where TRequest : class where TResponse : class
         {
             var responseHandlerInfo = GetResponseHandlerInfo(config, message, responseHandler);
             return new DelegateYieldPoint(context => SendRequest(context, message, responseHandlerInfo));
         }
 
         /// <inheritdoc />
-        public IYieldPoint YieldWithRequestSync<TRequest, TResponse>(TRequest message, Func<TResponse, IYieldPoint> responseHandler)
+        public IYieldPoint YieldWithRequest<TRequest, TResponse>(TRequest message, Func<TResponse, ValueTask<IYieldPoint>> responseHandler) where TRequest : class where TResponse : class
+        {
+            var responseHandlerInfo = GetResponseHandlerInfo(config, message, responseHandler);
+            return new DelegateYieldPoint(context => SendRequest(context, message, responseHandlerInfo));
+        }
+
+        /// <inheritdoc />
+        public IYieldPoint YieldWithRequestSync<TRequest, TResponse>(TRequest message, Func<TResponse, IYieldPoint> responseHandler) where TRequest : class where TResponse : class
         {
             var responseHandlerInfo = GetResponseHandlerInfo(config, message, responseHandler);
             return new DelegateYieldPoint(context => SendRequest(context, message, responseHandlerInfo));
@@ -52,7 +59,7 @@ namespace Tapeti.Flow.Default
         }
 
         /// <inheritdoc />
-        public IYieldPoint EndWithResponse<TResponse>(TResponse message)
+        public IYieldPoint EndWithResponse<TResponse>(TResponse message) where TResponse : class
         {
             return new DelegateYieldPoint(context => SendResponse(context, message));
         }
@@ -65,9 +72,9 @@ namespace Tapeti.Flow.Default
 
 
         internal async Task SendRequest(FlowContext context, object message, ResponseHandlerInfo responseHandlerInfo, 
-            string convergeMethodName = null, bool convergeMethodTaskSync = false, bool store = true)
+            string? convergeMethodName = null, bool convergeMethodTaskSync = false, bool store = true)
         {
-            if (context.FlowState == null)
+            if (!context.HasFlowStateAndLock)
             {
                 await CreateNewFlowState(context);
                 Debug.Assert(context.FlowState != null, "context.FlowState != null");
@@ -98,9 +105,9 @@ namespace Tapeti.Flow.Default
 
         private async Task SendResponse(FlowContext context, object message)
         {
-            var reply = context.FlowState == null
+            var reply = context.HasFlowStateAndLock
-                ? GetReply(context.HandlerContext)
+                ? context.FlowState.Metadata.Reply
-                : context.FlowState.Metadata.Reply;
+                : GetReply(context.HandlerContext);
 
             if (reply == null)
                 throw new YieldPointException("No response is required");
@@ -127,7 +134,7 @@ namespace Tapeti.Flow.Default
         {
             await context.Delete();
 
-            if (context.FlowState?.Metadata.Reply != null)
+            if (context.HasFlowStateAndLock && context.FlowState.Metadata.Reply != null)
                 throw new YieldPointException($"Flow must end with a response message of type {context.FlowState.Metadata.Reply.ResponseTypeName}");
         }
 
@@ -152,16 +159,15 @@ namespace Tapeti.Flow.Default
             if (binding.QueueName == null)
                 throw new ArgumentException("responseHandler is not yet subscribed to a queue, TapetiConnection.Subscribe must be called before starting a flow", nameof(responseHandler));
 
-            return new ResponseHandlerInfo
+            return new ResponseHandlerInfo(
-            {
+                MethodSerializer.Serialize(responseHandler.Method),
-                MethodName = MethodSerializer.Serialize(responseHandler.Method),
+                binding.QueueName,
-                ReplyToQueue = binding.QueueName,
+                binding.QueueType == QueueType.Durable
-                IsDurableQueue = binding.QueueType == QueueType.Durable
+            );
-            };
         }
 
 
-        private static ReplyMetadata GetReply(IFlowHandlerContext context)
+        private static ReplyMetadata? GetReply(IFlowHandlerContext context)
         {
             var requestAttribute = context.MessageContext?.Message?.GetType().GetCustomAttribute<RequestAttribute>();
             if (requestAttribute?.Response == null)
@@ -169,7 +175,7 @@ namespace Tapeti.Flow.Default
 
             return new ReplyMetadata
             {
-                CorrelationId = context.MessageContext.Properties.CorrelationId,
+                CorrelationId = context.MessageContext!.Properties.CorrelationId,
                 ReplyTo = context.MessageContext.Properties.ReplyTo,
                 ResponseTypeName = requestAttribute.Response.FullName,
                 Mandatory = context.MessageContext.Properties.Persistent.GetValueOrDefault(true)
@@ -181,39 +187,34 @@ namespace Tapeti.Flow.Default
             var flowStore = flowContext.HandlerContext.Config.DependencyResolver.Resolve<IFlowStore>();
 
             var flowID = Guid.NewGuid();
-            flowContext.FlowStateLock = await flowStore.LockFlowState(flowID);
+            var flowStateLock = await flowStore.LockFlowState(flowID);
 
-            if (flowContext.FlowStateLock == null)
+            if (flowStateLock == null)
                 throw new InvalidOperationException("Unable to lock a new flow");
 
-            flowContext.FlowState = new FlowState
+            var flowState = new FlowState
             {
-                Metadata = new FlowMetadata
+                Metadata = new FlowMetadata(GetReply(flowContext.HandlerContext))
-                {
-                    Reply = GetReply(flowContext.HandlerContext)
-                }
             };
+
+            flowContext.SetFlowState(flowState, flowStateLock);
         }
 
         
         /// <inheritdoc />
-        public async Task Execute(IFlowHandlerContext context, IYieldPoint yieldPoint)
+        public async ValueTask Execute(IFlowHandlerContext context, IYieldPoint yieldPoint)
         {
-            if (!(yieldPoint is DelegateYieldPoint executableYieldPoint))
+            if (yieldPoint is not DelegateYieldPoint executableYieldPoint)
-                throw new YieldPointException($"Yield point is required in controller {context.Controller.GetType().Name} for method {context.Method.Name}");
+                throw new YieldPointException($"Yield point is required in controller {context.Controller?.GetType().Name} for method {context.Method.Name}");
 
-            FlowContext flowContext = null;
+            FlowContext? flowContext = null;
             var disposeFlowContext = false;
 
             try
             {
-                var messageContext = context.MessageContext;
+                if (context.MessageContext == null || !context.MessageContext.TryGet<FlowMessageContextPayload>(out var flowPayload))
-                if (messageContext == null || !messageContext.TryGet<FlowMessageContextPayload>(out var flowPayload))
                 {
-                    flowContext = new FlowContext
+                    flowContext = new FlowContext(context);
-                    {
-                        HandlerContext = context
-                    };
 
                     // If we ended up here it is because of a Start. No point in storing the new FlowContext
                     // in the messageContext as the yield point is the last to execute.
@@ -229,7 +230,7 @@ namespace Tapeti.Flow.Default
                 catch (YieldPointException e)
                 {
                     // Useful for debugging
-                    e.Data["Tapeti.Controller.Name"] = context.Controller.GetType().FullName;
+                    e.Data["Tapeti.Controller.Name"] = context.Controller?.GetType().FullName;
                     e.Data["Tapeti.Controller.Method"] = context.Method.Name;
                     throw;
                 }
@@ -239,44 +240,66 @@ namespace Tapeti.Flow.Default
             finally
             {
                 if (disposeFlowContext)
-                    flowContext.Dispose();
+                    flowContext?.Dispose();
             }
         }
 
 
         /// <inheritdoc />
-        public IFlowParallelRequest GetParallelRequest(IFlowHandlerContext context)
+        public IFlowParallelRequest? GetParallelRequest(IFlowHandlerContext context)
         {
-            return context.MessageContext.TryGet<FlowMessageContextPayload>(out var flowPayload)
+            return context.MessageContext != null && context.MessageContext.TryGet<FlowMessageContextPayload>(out var flowPayload)
                 ? new ParallelRequest(config, this, flowPayload.FlowContext)
                 : null;
         }
 
 
         /// <inheritdoc />
-        public Task Converge(IFlowHandlerContext context)
+        public ValueTask Converge(IFlowHandlerContext context)
         {
-            return Execute(context, new DelegateYieldPoint(flowContext => 
+            return Execute(context, new DelegateYieldPoint(async flowContext =>
-                Converge(flowContext, flowContext.ContinuationMetadata.ConvergeMethodName, flowContext.ContinuationMetadata.ConvergeMethodSync)));
+            {
+                if (flowContext.ContinuationMetadata == null)
+                    throw new InvalidOperationException("Missing ContinuationMetadata in FlowContext");
+
+                if (flowContext.ContinuationMetadata.ConvergeMethodName == null)
+                    throw new InvalidOperationException("Missing ConvergeMethodName in FlowContext ContinuationMetadata");
+
+                await Converge(flowContext, flowContext.ContinuationMetadata.ConvergeMethodName, flowContext.ContinuationMetadata.ConvergeMethodSync);
+            }));
         }
 
 
         internal async Task Converge(FlowContext flowContext, string convergeMethodName, bool convergeMethodSync)
         {
-            IYieldPoint yieldPoint;
+            IYieldPoint? yieldPoint;
+
+            if (flowContext.HandlerContext == null)
+                throw new InvalidOperationException($"Missing HandleContext in FlowContext for converge method {convergeMethodName}");
+
+            if (flowContext.HandlerContext.MessageContext == null)
+                throw new InvalidOperationException($"Missing MessageContext in FlowContext for converge method {convergeMethodName}");
 
             if (!flowContext.HandlerContext.MessageContext.TryGet<ControllerMessageContextPayload>(out var controllerPayload))
                 throw new ArgumentException("Context does not contain a controller payload", nameof(flowContext));
 
+            if (controllerPayload.Controller == null)
+                throw new InvalidOperationException($"Controller is not available for converge method {convergeMethodName} (method is static?)");
 
             var method = controllerPayload.Controller.GetType().GetMethod(convergeMethodName, BindingFlags.NonPublic | BindingFlags.Instance);
             if (method == null)
                 throw new ArgumentException($"Unknown converge method in controller {controllerPayload.Controller.GetType().Name}: {convergeMethodName}");
 
             if (convergeMethodSync)
-                yieldPoint = (IYieldPoint)method.Invoke(controllerPayload.Controller, new object[] { });
+                yieldPoint = (IYieldPoint?)method.Invoke(controllerPayload.Controller, new object[] { });
             else
-                yieldPoint = await(Task<IYieldPoint>)method.Invoke(controllerPayload.Controller, new object[] { });
+            {
+                var yieldPointTask = method.Invoke(controllerPayload.Controller, new object[] { });
+                if (yieldPointTask == null)
+                    throw new YieldPointException($"Yield point is required in controller {controllerPayload.Controller.GetType().Name} for converge method {convergeMethodName}");
+
+                yieldPoint = await (Task<IYieldPoint>)yieldPointTask;
+            }
 
             if (yieldPoint == null)
                 throw new YieldPointException($"Yield point is required in controller {controllerPayload.Controller.GetType().Name} for converge method {convergeMethodName}");
@@ -290,14 +313,21 @@ namespace Tapeti.Flow.Default
         {
             private class RequestInfo
             {
-                public object Message { get; set; }
+                public object Message { get; }
-                public ResponseHandlerInfo ResponseHandlerInfo { get; set; }
+                public ResponseHandlerInfo ResponseHandlerInfo { get; }
+
+                
+                public RequestInfo(object message, ResponseHandlerInfo responseHandlerInfo)
+                {
+                    Message = message;
+                    ResponseHandlerInfo = responseHandlerInfo;
+                }
             }
 
 
             private readonly ITapetiConfig config;
             private readonly FlowProvider flowProvider;
-            private readonly List<RequestInfo> requests = new List<RequestInfo>();
+            private readonly List<RequestInfo> requests = new();
 
 
             public ParallelRequestBuilder(ITapetiConfig config, FlowProvider flowProvider)
@@ -307,32 +337,40 @@ namespace Tapeti.Flow.Default
             }
 
 
-            public IFlowParallelRequestBuilder AddRequest<TRequest, TResponse>(TRequest message, Func<TResponse, Task> responseHandler)
+            public IFlowParallelRequestBuilder AddRequest<TRequest, TResponse>(TRequest message, Func<TResponse, Task> responseHandler) where TRequest : class where TResponse : class
+            {
+                return InternalAddRequest(message, responseHandler);
+            }
+
+            public IFlowParallelRequestBuilder AddRequest<TRequest, TResponse>(TRequest message, Func<TResponse, ValueTask> responseHandler) where TRequest : class where TResponse : class
+            {
+                return InternalAddRequest(message, responseHandler);
+            }
+
+            public IFlowParallelRequestBuilder AddRequest<TRequest, TResponse>(TRequest message, Func<TResponse, IFlowParallelRequest, Task> responseHandler) where TRequest : class where TResponse : class
+            {
+                return InternalAddRequest(message, responseHandler);
+            }
+
+            public IFlowParallelRequestBuilder AddRequest<TRequest, TResponse>(TRequest message, Func<TResponse, IFlowParallelRequest, ValueTask> responseHandler) where TRequest : class where TResponse : class
+            {
+                return InternalAddRequest(message, responseHandler);
+            }
+
+            public IFlowParallelRequestBuilder AddRequestSync<TRequest, TResponse>(TRequest message, Action<TResponse> responseHandler) where TRequest : class where TResponse : class
+            {
+                return InternalAddRequest(message, responseHandler);
+            }
+
+            public IFlowParallelRequestBuilder AddRequestSync<TRequest, TResponse>(TRequest message, Action<TResponse, IFlowParallelRequest> responseHandler) where TRequest : class where TResponse : class
             {
                 return InternalAddRequest(message, responseHandler);
             }
 
 
-            public IFlowParallelRequestBuilder AddRequest<TRequest, TResponse>(TRequest message, Func<TResponse, IFlowParallelRequest, Task> responseHandler)
+            private IFlowParallelRequestBuilder InternalAddRequest(object message, Delegate responseHandler)
             {
-                return InternalAddRequest(message, responseHandler);
+                requests.Add(new RequestInfo(message, GetResponseHandlerInfo(config, message, responseHandler)));
-            }
-
-
-            public IFlowParallelRequestBuilder AddRequestSync<TRequest, TResponse>(TRequest message, Action<TResponse> responseHandler)
-            {
-                return InternalAddRequest(message, responseHandler);
-            }
-
-
-            public IFlowParallelRequestBuilder InternalAddRequest(object message, Delegate responseHandler)
-            {
-                requests.Add(new RequestInfo
-                {
-                    Message = message,
-                    ResponseHandlerInfo = GetResponseHandlerInfo(config, message, responseHandler)
-                });
-
                 return this;
             }
 
@@ -342,7 +380,6 @@ namespace Tapeti.Flow.Default
                 return BuildYieldPoint(continuation, false, noRequestsBehaviour);
             }
 
-
             public IYieldPoint YieldSync(Func<IYieldPoint> continuation, FlowNoRequestsBehaviour noRequestsBehaviour = FlowNoRequestsBehaviour.Exception)
             {
                 return BuildYieldPoint(continuation, true, noRequestsBehaviour);
@@ -353,29 +390,21 @@ namespace Tapeti.Flow.Default
             {
                 if (requests.Count == 0)
                 {
-                    switch (noRequestsBehaviour)
+                    return noRequestsBehaviour switch
                     {
-                        case FlowNoRequestsBehaviour.Exception:
+                        FlowNoRequestsBehaviour.Exception => throw new YieldPointException("At least one request must be added before yielding a parallel request"),
-                            throw new YieldPointException("At least one request must be added before yielding a parallel request");
+                        FlowNoRequestsBehaviour.Converge => new DelegateYieldPoint(context => flowProvider.Converge(context, convergeMethod.Method.Name, convergeMethodSync)),
-
+                        FlowNoRequestsBehaviour.EndFlow => new DelegateYieldPoint(EndFlow),
-                        case FlowNoRequestsBehaviour.Converge:
+                        _ => throw new ArgumentOutOfRangeException(nameof(noRequestsBehaviour), noRequestsBehaviour, null)
-                            return new DelegateYieldPoint(context =>
+                    };
-                                flowProvider.Converge(context, convergeMethod.Method.Name, convergeMethodSync));
-
-                        case FlowNoRequestsBehaviour.EndFlow:
-                            return new DelegateYieldPoint(EndFlow);
-
-                        default:
-                            throw new ArgumentOutOfRangeException(nameof(noRequestsBehaviour), noRequestsBehaviour, null);
-                    }
                 }
 
-                if (convergeMethod?.Method == null)
+                if (convergeMethod.Method == null)
                     throw new ArgumentNullException(nameof(convergeMethod));
 
                 return new DelegateYieldPoint(async context =>
                 {
-                    if (convergeMethod.Method.DeclaringType != context.HandlerContext.Controller.GetType())
+                    if (convergeMethod.Method.DeclaringType != context.HandlerContext.Controller?.GetType())
                         throw new YieldPointException("Converge method must be in the same controller class");
 
                     await Task.WhenAll(requests.Select(requestInfo =>
@@ -408,19 +437,19 @@ namespace Tapeti.Flow.Default
             }
 
 
-            public Task AddRequest<TRequest, TResponse>(TRequest message, Func<TResponse, Task> responseHandler)
+            public Task AddRequest<TRequest, TResponse>(TRequest message, Func<TResponse, Task> responseHandler) where TRequest : class where TResponse : class
             {
                 return InternalAddRequest(message, responseHandler);
             }
 
 
-            public Task AddRequest<TRequest, TResponse>(TRequest message, Func<TResponse, IFlowParallelRequest, Task> responseHandler)
+            public Task AddRequest<TRequest, TResponse>(TRequest message, Func<TResponse, IFlowParallelRequest, Task> responseHandler) where TRequest : class where TResponse : class
             {
                 return InternalAddRequest(message, responseHandler);
             }
 
 
-            public Task AddRequestSync<TRequest, TResponse>(TRequest message, Action<TResponse> responseHandler)
+            public Task AddRequestSync<TRequest, TResponse>(TRequest message, Action<TResponse> responseHandler) where TRequest : class where TResponse : class
             {
                 return InternalAddRequest(message, responseHandler);
             }
@@ -430,6 +459,9 @@ namespace Tapeti.Flow.Default
             {
                 var responseHandlerInfo = GetResponseHandlerInfo(config, message, responseHandler);
 
+                if (flowContext.ContinuationMetadata == null)
+                    throw new InvalidOperationException("No ContinuationMetadata in FlowContext");
+
                 return flowProvider.SendRequest(
                     flowContext, 
                     message, 
@@ -443,9 +475,17 @@ namespace Tapeti.Flow.Default
 
         internal class ResponseHandlerInfo
         {
-            public string MethodName { get; set; }
+            public string MethodName { get; }
-            public string ReplyToQueue { get; set; }
+            public string ReplyToQueue { get; }
-            public bool IsDurableQueue { get; set; }
+            public bool IsDurableQueue { get; }
+
+
+            public ResponseHandlerInfo(string methodName, string replyToQueue, bool isDurableQueue)
+            {
+                MethodName = methodName;
+                ReplyToQueue = replyToQueue;
+                IsDurableQueue = isDurableQueue;
+            }
         }
     }
 }

Tapeti.Flow/Default/FlowStarter.cs

@@ -6,7 +6,6 @@ using Tapeti.Config;
 
 namespace Tapeti.Flow.Default
 {
-    /// <inheritdoc />
     /// <summary>
     /// Default implementation for IFlowStarter.
     /// </summary>
@@ -26,39 +25,38 @@ namespace Tapeti.Flow.Default
         /// <inheritdoc />
         public async Task Start<TController>(Expression<Func<TController, Func<IYieldPoint>>> methodSelector) where TController : class
         {
-            await CallControllerMethod<TController>(GetExpressionMethod(methodSelector), value => Task.FromResult((IYieldPoint)value), new object[] { });
+            await CallControllerMethod<TController>(GetExpressionMethod(methodSelector), value => Task.FromResult((IYieldPoint)value), Array.Empty<object?>());
         }
 
         /// <inheritdoc />
         public async Task Start<TController>(Expression<Func<TController, Func<Task<IYieldPoint>>>> methodSelector) where TController : class
         {
-            await CallControllerMethod<TController>(GetExpressionMethod(methodSelector), value => (Task<IYieldPoint>)value, new object[] {});
+            await CallControllerMethod<TController>(GetExpressionMethod(methodSelector), value => (Task<IYieldPoint>)value, Array.Empty<object?>());
         }
 
         /// <inheritdoc />
         public async Task Start<TController, TParameter>(Expression<Func<TController, Func<TParameter, IYieldPoint>>> methodSelector, TParameter parameter) where TController : class
         {
-            await CallControllerMethod<TController>(GetExpressionMethod(methodSelector), value => Task.FromResult((IYieldPoint)value), new object[] {parameter});
+            await CallControllerMethod<TController>(GetExpressionMethod(methodSelector), value => Task.FromResult((IYieldPoint)value), new object?[] {parameter});
         }
 
         /// <inheritdoc />
         public async Task Start<TController, TParameter>(Expression<Func<TController, Func<TParameter, Task<IYieldPoint>>>> methodSelector, TParameter parameter) where TController : class
         {
-            await CallControllerMethod<TController>(GetExpressionMethod(methodSelector), value => (Task<IYieldPoint>)value, new object[] {parameter});
+            await CallControllerMethod<TController>(GetExpressionMethod(methodSelector), value => (Task<IYieldPoint>)value, new object?[] {parameter});
         }
 
 
-        private async Task CallControllerMethod<TController>(MethodInfo method, Func<object, Task<IYieldPoint>> getYieldPointResult, object[] parameters) where TController : class
+        private async Task CallControllerMethod<TController>(MethodInfo method, Func<object, Task<IYieldPoint>> getYieldPointResult, object?[] parameters) where TController : class
         {
             var controller = config.DependencyResolver.Resolve<TController>();
-            var yieldPoint = await getYieldPointResult(method.Invoke(controller, parameters));
+            var result = method.Invoke(controller, parameters);
+            if (result == null)
+                throw new InvalidOperationException($"Method {method.Name} must return an IYieldPoint or Task<IYieldPoint>, got null");
 
-            var context = new FlowHandlerContext
+            var yieldPoint = await getYieldPointResult(result);
-            {
+
-                Config = config,
+            var context = new FlowHandlerContext(config, controller, method);
-                Controller = controller,
-                Method = method
-            };
 
             var flowHandler = config.DependencyResolver.Resolve<IFlowHandler>();
             await flowHandler.Execute(context, yieldPoint);

Tapeti.Flow/Default/FlowState.cs

@@ -9,8 +9,8 @@ namespace Tapeti.Flow.Default
     /// </summary>
     public class FlowState
     {
-        private FlowMetadata metadata;
+        private FlowMetadata? metadata;
-        private Dictionary<Guid, ContinuationMetadata> continuations;
+        private Dictionary<Guid, ContinuationMetadata>? continuations;
 
 
         /// <summary>
@@ -18,7 +18,7 @@ namespace Tapeti.Flow.Default
         /// </summary>
         public FlowMetadata Metadata
         {
-            get => metadata ?? (metadata = new FlowMetadata());
+            get => metadata ??= new FlowMetadata(null);
             set => metadata = value;
         }
 
@@ -26,7 +26,7 @@ namespace Tapeti.Flow.Default
         /// <summary>
         /// Contains the serialized state which is restored when a flow continues.
         /// </summary>
-        public string Data { get; set; }
+        public string? Data { get; set; }
 
 
         /// <summary>
@@ -34,7 +34,7 @@ namespace Tapeti.Flow.Default
         /// </summary>
         public Dictionary<Guid, ContinuationMetadata> Continuations
         {
-            get => continuations ?? (continuations = new Dictionary<Guid, ContinuationMetadata>());
+            get => continuations ??= new Dictionary<Guid, ContinuationMetadata>();
             set => continuations = value;
         }
 
@@ -45,7 +45,7 @@ namespace Tapeti.Flow.Default
         public FlowState Clone()
         {
             return new FlowState {
-                metadata = metadata.Clone(),
+                metadata = metadata?.Clone(),
                 Data = Data,
                 continuations = continuations?.ToDictionary(kv => kv.Key, kv => kv.Value.Clone())
             };
@@ -61,7 +61,14 @@ namespace Tapeti.Flow.Default
         /// <summary>
         /// Contains information about the expected response for this flow.
         /// </summary>
-        public ReplyMetadata Reply { get; set; }
+        public ReplyMetadata? Reply { get; }
+
+
+        /// <inheritdoc cref="FlowMetadata"/>
+        public FlowMetadata(ReplyMetadata? reply)
+        {
+            Reply = reply;
+        }
 
         
         /// <summary>
@@ -69,10 +76,7 @@ namespace Tapeti.Flow.Default
         /// </summary>
         public FlowMetadata Clone()
         {
-            return new FlowMetadata
+            return new FlowMetadata(Reply);
-            {
-                Reply = Reply?.Clone()
-            };
         }
     }
 
@@ -85,17 +89,17 @@ namespace Tapeti.Flow.Default
         /// <summary>
         /// The queue to which the response should be sent.
         /// </summary>
-        public string ReplyTo { get; set; }
+        public string? ReplyTo { get; set; }
 
         /// <summary>
         /// The correlation ID included in the original request.
         /// </summary>
-        public string CorrelationId { get; set; }
+        public string? CorrelationId { get; set; }
 
         /// <summary>
         /// The expected response message class.
         /// </summary>
-        public string ResponseTypeName { get; set; }
+        public string? ResponseTypeName { get; set; }
 
         /// <summary>
         /// Indicates whether the response should be sent a mandatory.
@@ -128,12 +132,12 @@ namespace Tapeti.Flow.Default
         /// <summary>
         /// The name of the method which will handle the response.
         /// </summary>
-        public string MethodName { get; set; }
+        public string? MethodName { get; set; }
 
         /// <summary>
         /// The name of the method which is called when all responses have been processed.
         /// </summary>
-        public string ConvergeMethodName { get; set; }
+        public string? ConvergeMethodName { get; set; }
 
         /// <summary>
         /// Determines if the converge method is synchronous or asynchronous.

Tapeti.Flow/Default/FlowStore.cs

@@ -9,7 +9,6 @@ using Tapeti.Flow.FlowHelpers;
 
 namespace Tapeti.Flow.Default
 {
-    /// <inheritdoc />
     /// <summary>
     /// Default implementation of IFlowStore.
     /// </summary>
@@ -17,11 +16,11 @@ namespace Tapeti.Flow.Default
     {
         private class CachedFlowState
         {
-            public readonly FlowState FlowState;
+            public readonly FlowState? FlowState;
             public readonly DateTime CreationTime;
             public readonly bool IsPersistent;
 
-            public CachedFlowState(FlowState flowState, DateTime creationTime, bool isPersistent)
+            public CachedFlowState(FlowState? flowState, DateTime creationTime, bool isPersistent)
             {
                 FlowState = flowState;
                 CreationTime = creationTime;
@@ -29,10 +28,10 @@ namespace Tapeti.Flow.Default
             }
         }
 
-        private readonly ConcurrentDictionary<Guid, CachedFlowState> flowStates = new ConcurrentDictionary<Guid, CachedFlowState>();
+        private readonly ConcurrentDictionary<Guid, CachedFlowState> flowStates = new();
-        private readonly ConcurrentDictionary<Guid, Guid> continuationLookup = new ConcurrentDictionary<Guid, Guid>();
+        private readonly ConcurrentDictionary<Guid, Guid> continuationLookup = new();
-        private readonly LockCollection<Guid> locks = new LockCollection<Guid>(EqualityComparer<Guid>.Default);
+        private readonly LockCollection<Guid> locks = new(EqualityComparer<Guid>.Default);
-        private HashSet<string> validatedMethods;
+        private HashSet<string>? validatedMethods;
 
         private readonly IFlowRepository repository;
         private readonly ITapetiConfig config;
@@ -51,7 +50,7 @@ namespace Tapeti.Flow.Default
 
 
         /// <inheritdoc />
-        public async Task Load()
+        public async ValueTask Load()
         {
             if (inUse)
                 throw new InvalidOperationException("Can only load the saved state once.");
@@ -86,10 +85,13 @@ namespace Tapeti.Flow.Default
 
         private void ValidateContinuation(Guid flowId, Guid continuationId, ContinuationMetadata metadata)
         {
+            if (string.IsNullOrEmpty(metadata.MethodName))
+                return;
+
             // We could check all the things that are required for a continuation or converge method, but this should suffice
             // for the common scenario where you change code without realizing that it's signature has been persisted
             // ReSharper disable once InvertIf
-            if (validatedMethods.Add(metadata.MethodName))
+            if (validatedMethods!.Add(metadata.MethodName))
             {
                 var methodInfo = MethodSerializer.Deserialize(metadata.MethodName);
                 if (methodInfo == null)
@@ -114,17 +116,17 @@ namespace Tapeti.Flow.Default
 
 
         /// <inheritdoc />
-        public Task<Guid?> FindFlowID(Guid continuationID)
+        public ValueTask<Guid?> FindFlowID(Guid continuationID)
         {
             if (!loaded)
                 throw new InvalidOperationException("Flow store is not yet loaded.");
 
-            return Task.FromResult(continuationLookup.TryGetValue(continuationID, out var result) ? result : (Guid?)null);
+            return new ValueTask<Guid?>(continuationLookup.TryGetValue(continuationID, out var result) ? result : null);
         }
 
 
         /// <inheritdoc />
-        public async Task<IFlowStateLock> LockFlowState(Guid flowID)
+        public async ValueTask<IFlowStateLock> LockFlowState(Guid flowID)
         {
             if (!loaded)
                 throw new InvalidOperationException("Flow store should be loaded before storing flows.");
@@ -137,22 +139,22 @@ namespace Tapeti.Flow.Default
 
 
         /// <inheritdoc />
-        public Task<IEnumerable<ActiveFlow>> GetActiveFlows(TimeSpan minimumAge)
+        public ValueTask<IEnumerable<ActiveFlow>> GetActiveFlows(TimeSpan minimumAge)
         {
             var maximumDateTime = DateTime.UtcNow - minimumAge;
 
-            return Task.FromResult(flowStates
+            return new ValueTask<IEnumerable<ActiveFlow>>(flowStates
                 .Where(p => p.Value.CreationTime <= maximumDateTime)
                 .Select(p => new ActiveFlow(p.Key, p.Value.CreationTime))
-                .ToArray() as IEnumerable<ActiveFlow>);
+                .ToArray());
         }
 
 
         private class FlowStateLock : IFlowStateLock
         {
             private readonly FlowStore owner;
-            private volatile IDisposable flowLock;
+            private volatile IDisposable? flowLock;
-            private CachedFlowState cachedFlowState;
+            private CachedFlowState? cachedFlowState;
 
             public Guid FlowID { get; }
 
@@ -173,15 +175,15 @@ namespace Tapeti.Flow.Default
                 l?.Dispose();
             }
 
-            public Task<FlowState> GetFlowState()
+            public ValueTask<FlowState?> GetFlowState()
             {
                 if (flowLock == null)
                     throw new ObjectDisposedException("FlowStateLock");
 
-                return Task.FromResult(cachedFlowState?.FlowState?.Clone());
+                return new ValueTask<FlowState?>(cachedFlowState?.FlowState?.Clone());
             }
 
-            public async Task StoreFlowState(FlowState newFlowState, bool persistent)
+            public async ValueTask StoreFlowState(FlowState newFlowState, bool persistent)
             {
                 if (flowLock == null)
                     throw new ObjectDisposedException("FlowStateLock");
@@ -190,13 +192,13 @@ namespace Tapeti.Flow.Default
                 newFlowState = newFlowState.Clone();
 
                 // Update the lookup dictionary for the ContinuationIDs
-                if (cachedFlowState != null)
+                if (cachedFlowState?.FlowState != null)
                 {
                     foreach (var removedContinuation in cachedFlowState.FlowState.Continuations.Keys.Where(k => !newFlowState.Continuations.ContainsKey(k)))
                         owner.continuationLookup.TryRemove(removedContinuation, out _);
                 }
 
-                foreach (var addedContinuation in newFlowState.Continuations.Where(c => cachedFlowState == null || !cachedFlowState.FlowState.Continuations.ContainsKey(c.Key)))
+                foreach (var addedContinuation in newFlowState.Continuations.Where(c => cachedFlowState?.FlowState == null || !cachedFlowState.FlowState.Continuations.ContainsKey(c.Key)))
                 {
                     owner.continuationLookup.TryAdd(addedContinuation.Key, FlowID);
                 }
@@ -204,7 +206,7 @@ namespace Tapeti.Flow.Default
                 var isNew = cachedFlowState == null;
                 var wasPersistent = cachedFlowState?.IsPersistent ?? false;
 
-                cachedFlowState = new CachedFlowState(newFlowState, isNew ? DateTime.UtcNow : cachedFlowState.CreationTime, persistent);
+                cachedFlowState = new CachedFlowState(newFlowState, isNew ? DateTime.UtcNow : cachedFlowState!.CreationTime, persistent);
                 owner.flowStates[FlowID] = cachedFlowState;
 
                 if (persistent)
@@ -227,12 +229,12 @@ namespace Tapeti.Flow.Default
                 }
             }
 
-            public async Task DeleteFlowState()
+            public async ValueTask DeleteFlowState()
             {
                 if (flowLock == null)
                     throw new ObjectDisposedException("FlowStateLock");
 
-                if (cachedFlowState != null)
+                if (cachedFlowState?.FlowState != null)
                 {
                     foreach (var removedContinuation in cachedFlowState.FlowState.Continuations.Keys)
                         owner.continuationLookup.TryRemove(removedContinuation, out _);
@@ -240,7 +242,7 @@ namespace Tapeti.Flow.Default
                     owner.flowStates.TryRemove(FlowID, out var removedFlowState);
                     cachedFlowState = null;
 
-                    if (removedFlowState.IsPersistent)
+                    if (removedFlowState is { IsPersistent: true })
                         await owner.repository.DeleteState(FlowID);
                 }
             }

Tapeti.Flow/Default/NonPersistentFlowRepository.cs

@@ -5,33 +5,32 @@ using System.Threading.Tasks;
 
 namespace Tapeti.Flow.Default
 {
-    /// <inheritdoc />
     /// <summary>
     /// Default implementation for IFlowRepository. Does not persist any state, relying on the FlowStore's cache instead.
     /// </summary>
     public class NonPersistentFlowRepository : IFlowRepository
     {
-        Task<IEnumerable<FlowRecord<T>>> IFlowRepository.GetStates<T>()
+        ValueTask<IEnumerable<FlowRecord<T>>> IFlowRepository.GetStates<T>()
         {
-            return Task.FromResult(Enumerable.Empty<FlowRecord<T>>());
+            return new ValueTask<IEnumerable<FlowRecord<T>>>(Enumerable.Empty<FlowRecord<T>>());
         }
 
         /// <inheritdoc />
-        public Task CreateState<T>(Guid flowID, T state, DateTime timestamp)
+        public ValueTask CreateState<T>(Guid flowID, T state, DateTime timestamp)
         {
-            return Task.CompletedTask;
+            return default;
         }
 
         /// <inheritdoc />
-        public Task UpdateState<T>(Guid flowID, T state)
+        public ValueTask UpdateState<T>(Guid flowID, T state)
         {
-            return Task.CompletedTask;
+            return default;
         }
 
         /// <inheritdoc />
-        public Task DeleteState(Guid flowID)
+        public ValueTask DeleteState(Guid flowID)
         {
-            return Task.CompletedTask;
+            return default;
         }
     }
 }

Tapeti.Flow/FlowExtension.cs

@@ -4,17 +4,16 @@ using Tapeti.Flow.Default;
 
 namespace Tapeti.Flow
 {
-    /// <inheritdoc />
     /// <summary>
     /// Provides the Flow middleware.
     /// </summary>
     public class FlowExtension : ITapetiExtension
     {
-        private readonly IFlowRepository flowRepository;
+        private readonly IFlowRepository? flowRepository;
 
         /// <summary>
         /// </summary>
-        public FlowExtension(IFlowRepository flowRepository)
+        public FlowExtension(IFlowRepository? flowRepository)
         {
             this.flowRepository = flowRepository;
         }

Tapeti.Flow/FlowHelpers/LockCollection.cs

@@ -7,7 +7,7 @@ namespace Tapeti.Flow.FlowHelpers
     /// <summary>
     /// Implementation of an asynchronous locking mechanism.
     /// </summary>
-    public class LockCollection<T>
+    public class LockCollection<T> where T : notnull
     {
         private readonly Dictionary<T, LockItem> locks;
 
@@ -57,10 +57,10 @@ namespace Tapeti.Flow.FlowHelpers
 
         private class LockItem : IDisposable
         {
-            internal volatile LockItem Next;
+            internal volatile LockItem? Next;
 
             private readonly Dictionary<T, LockItem> locks;
-            private readonly TaskCompletionSource<IDisposable> tcs = new TaskCompletionSource<IDisposable>(TaskCreationOptions.RunContinuationsAsynchronously);
+            private readonly TaskCompletionSource<IDisposable> tcs = new(TaskCreationOptions.RunContinuationsAsynchronously);
             private readonly T key;
 
             public LockItem(Dictionary<T, LockItem> locks, T key)

Tapeti.Flow/FlowHelpers/MethodSerializer.cs

@@ -18,14 +18,14 @@ namespace Tapeti.Flow.FlowHelpers
         }
 
 
-        private static readonly Regex DeserializeRegex = new Regex("^(?<method>.+?)@(?<assembly>.+?):(?<type>.+?)$");
+        private static readonly Regex DeserializeRegex = new("^(?<method>.+?)@(?<assembly>.+?):(?<type>.+?)$");
 
         
         /// <summary>
         /// Deserializes the serialized method representation back into it's MethodInfo, or null if not found.
         /// </summary>
         /// <param name="serializedMethod"></param>
-        public static MethodInfo Deserialize(string serializedMethod)
+        public static MethodInfo? Deserialize(string serializedMethod)
         {
             var match = DeserializeRegex.Match(serializedMethod);
             if (!match.Success)
@@ -35,8 +35,6 @@ namespace Tapeti.Flow.FlowHelpers
             try
             {
                 assembly = Assembly.Load(match.Groups["assembly"].Value);
-                if (assembly == null)
-                    return null;
             }
             catch
             {

Tapeti.Flow/FlowMessageContextPayload.cs

@@ -16,9 +16,8 @@ namespace Tapeti.Flow
         /// parallel flow is done and the convergeMethod will be called.
         /// Temporarily disables storing the flow state.
         /// </summary>
-        public bool FlowIsConverging => FlowContext != null && 
+        public bool FlowIsConverging => FlowContext.FlowState.Continuations.Count == 0 &&
-                                        FlowContext.FlowState.Continuations.Count == 0 &&
+                                        FlowContext.ContinuationMetadata?.ConvergeMethodName != null;
-                                        FlowContext.ContinuationMetadata.ConvergeMethodName != null;
 
         
         public FlowMessageContextPayload(FlowContext flowContext)
@@ -29,7 +28,7 @@ namespace Tapeti.Flow
         
         public void Dispose()
         {
-            FlowContext?.Dispose();
+            FlowContext.Dispose();
         }
     }
 }

Tapeti.Flow/IFlowHandlerContext.cs

@@ -4,7 +4,6 @@ using Tapeti.Config;
 
 namespace Tapeti.Flow
 {
-    /// <inheritdoc />
     /// <summary>
     /// Provides information about the handler for the flow.
     /// </summary>
@@ -19,7 +18,7 @@ namespace Tapeti.Flow
         /// <summary>
         /// An instance of the controller which starts or continues the flow.
         /// </summary>
-        object Controller { get; }
+        object? Controller { get; }
 
 
         /// <summary>
@@ -32,6 +31,6 @@ namespace Tapeti.Flow
         /// Access to the message context if this is a continuated flow.
         /// Will be null when in a starting flow.
         /// </summary>
-        IMessageContext MessageContext { get; }
+        IMessageContext? MessageContext { get; }
     }
 }

Tapeti.Flow/IFlowProvider.cs

@@ -20,7 +20,19 @@ namespace Tapeti.Flow
         /// <param name="responseHandler"></param>
         /// <typeparam name="TRequest"></typeparam>
         /// <typeparam name="TResponse"></typeparam>
-        IYieldPoint YieldWithRequest<TRequest, TResponse>(TRequest message, Func<TResponse, Task<IYieldPoint>> responseHandler);
+        IYieldPoint YieldWithRequest<TRequest, TResponse>(TRequest message, Func<TResponse, Task<IYieldPoint>> responseHandler) where TRequest : class where TResponse : class;
+
+
+        /// <summary>
+        /// Publish a request message and continue the flow when the response arrives.
+        /// The request message must be marked with the [Request] attribute, and the
+        /// Response type must match. Used for asynchronous response handlers.
+        /// </summary>
+        /// <param name="message"></param>
+        /// <param name="responseHandler"></param>
+        /// <typeparam name="TRequest"></typeparam>
+        /// <typeparam name="TResponse"></typeparam>
+        IYieldPoint YieldWithRequest<TRequest, TResponse>(TRequest message, Func<TResponse, ValueTask<IYieldPoint>> responseHandler) where TRequest : class where TResponse : class;
 
 
         /// <summary>
@@ -39,7 +51,7 @@ namespace Tapeti.Flow
         /// <typeparam name="TRequest"></typeparam>
         /// <typeparam name="TResponse"></typeparam>
         /// <returns></returns>
-        IYieldPoint YieldWithRequestSync<TRequest, TResponse>(TRequest message, Func<TResponse, IYieldPoint> responseHandler);
+        IYieldPoint YieldWithRequestSync<TRequest, TResponse>(TRequest message, Func<TResponse, IYieldPoint> responseHandler) where TRequest : class where TResponse : class;
 
 
         /// <summary>
@@ -55,7 +67,7 @@ namespace Tapeti.Flow
         /// </summary>
         /// <param name="message"></param>
         /// <typeparam name="TResponse"></typeparam>
-        IYieldPoint EndWithResponse<TResponse>(TResponse message);
+        IYieldPoint EndWithResponse<TResponse>(TResponse message) where TResponse : class;
 
 
         /// <summary>
@@ -108,19 +120,19 @@ namespace Tapeti.Flow
         /// </summary>
         /// <param name="context"></param>
         /// <param name="yieldPoint"></param>
-        Task Execute(IFlowHandlerContext context, IYieldPoint yieldPoint);
+        ValueTask Execute(IFlowHandlerContext context, IYieldPoint yieldPoint);
 
 
         /// <summary>
         /// Returns the parallel request for the given message context.
         /// </summary>
-        IFlowParallelRequest GetParallelRequest(IFlowHandlerContext context);
+        IFlowParallelRequest? GetParallelRequest(IFlowHandlerContext context);
 
 
         /// <summary>
         /// Calls the converge method for a parallel flow.
         /// </summary>
-        Task Converge(IFlowHandlerContext context);
+        ValueTask Converge(IFlowHandlerContext context);
     }
 
 
@@ -162,14 +174,31 @@ namespace Tapeti.Flow
         /// </summary>
         /// <param name="message"></param>
         /// <param name="responseHandler"></param>
-        IFlowParallelRequestBuilder AddRequest<TRequest, TResponse>(TRequest message, Func<TResponse, Task> responseHandler);
+        IFlowParallelRequestBuilder AddRequest<TRequest, TResponse>(TRequest message, Func<TResponse, Task> responseHandler) where TRequest : class where TResponse : class;
+
+        /// <summary>
+        /// Publish a request message and continue the flow when the response arrives.
+        /// Note that the response handler can not influence the flow as it does not return a YieldPoint.
+        /// It can instead store state in the controller for the continuation passed to the Yield method.
+        /// Used for asynchronous response handlers.
+        /// </summary>
+        /// <param name="message"></param>
+        /// <param name="responseHandler"></param>
+        IFlowParallelRequestBuilder AddRequest<TRequest, TResponse>(TRequest message, Func<TResponse, ValueTask> responseHandler) where TRequest : class where TResponse : class;
 
         /// <remarks>
         /// This overload allows the response handler access to the IFlowParallelRequest interface, which
         /// can be used to add additional requests to the parallel request before the continuation method passed to the Yield method is called.
         /// </remarks>
         /// <inheritdoc cref="AddRequest{TRequest,TResponse}(TRequest,Func{TResponse,Task})"/>
-        IFlowParallelRequestBuilder AddRequest<TRequest, TResponse>(TRequest message, Func<TResponse, IFlowParallelRequest, Task> responseHandler);
+        IFlowParallelRequestBuilder AddRequest<TRequest, TResponse>(TRequest message, Func<TResponse, IFlowParallelRequest, Task> responseHandler) where TRequest : class where TResponse : class;
+
+        /// <remarks>
+        /// This overload allows the response handler access to the IFlowParallelRequest interface, which
+        /// can be used to add additional requests to the parallel request before the continuation method passed to the Yield method is called.
+        /// </remarks>
+        /// <inheritdoc cref="AddRequest{TRequest,TResponse}(TRequest,Func{TResponse,ValueTask})"/>
+        IFlowParallelRequestBuilder AddRequest<TRequest, TResponse>(TRequest message, Func<TResponse, IFlowParallelRequest, ValueTask> responseHandler) where TRequest : class where TResponse : class;
 
         /// <summary>
         /// Publish a request message and continue the flow when the response arrives.
@@ -179,7 +208,14 @@ namespace Tapeti.Flow
         /// </summary>
         /// <param name="message"></param>
         /// <param name="responseHandler"></param>
-        IFlowParallelRequestBuilder AddRequestSync<TRequest, TResponse>(TRequest message, Action<TResponse> responseHandler);
+        IFlowParallelRequestBuilder AddRequestSync<TRequest, TResponse>(TRequest message, Action<TResponse> responseHandler) where TRequest : class where TResponse : class;
+
+        /// <remarks>
+        /// This overload allows the response handler access to the IFlowParallelRequest interface, which
+        /// can be used to add additional requests to the parallel request before the continuation method passed to the Yield method is called.
+        /// </remarks>
+        /// <inheritdoc cref="AddRequestSync{TRequest,TResponse}(TRequest,Action{TResponse})"/>
+        IFlowParallelRequestBuilder AddRequestSync<TRequest, TResponse>(TRequest message, Action<TResponse, IFlowParallelRequest> responseHandler) where TRequest : class where TResponse : class;
 
         /// There is no Sync overload with an IFlowParallelRequest parameter, as the AddRequest methods for that are
         /// async, so you should always await them.
@@ -224,14 +260,14 @@ namespace Tapeti.Flow
         /// </summary>
         /// <param name="message"></param>
         /// <param name="responseHandler"></param>
-        Task AddRequest<TRequest, TResponse>(TRequest message, Func<TResponse, Task> responseHandler);
+        Task AddRequest<TRequest, TResponse>(TRequest message, Func<TResponse, Task> responseHandler) where TRequest : class where TResponse : class;
 
         /// <remarks>
         /// This overload allows the response handler access to the IFlowParallelRequest interface, which
         /// can be used to add additional requests to the parallel request before the continuation method passed to the Yield method is called.
         /// </remarks>
         /// <inheritdoc cref="AddRequest{TRequest,TResponse}(TRequest,Func{TResponse,Task})"/>
-        Task AddRequest<TRequest, TResponse>(TRequest message, Func<TResponse, IFlowParallelRequest, Task> responseHandler);
+        Task AddRequest<TRequest, TResponse>(TRequest message, Func<TResponse, IFlowParallelRequest, Task> responseHandler) where TRequest : class where TResponse : class;
 
         /// <summary>
         /// Publish a request message and continue the flow when the response arrives.
@@ -241,7 +277,7 @@ namespace Tapeti.Flow
         /// </summary>
         /// <param name="message"></param>
         /// <param name="responseHandler"></param>
-        Task AddRequestSync<TRequest, TResponse>(TRequest message, Action<TResponse> responseHandler);
+        Task AddRequestSync<TRequest, TResponse>(TRequest message, Action<TResponse> responseHandler) where TRequest : class where TResponse : class;
     }
 
 

Tapeti.Flow/IFlowRepository.cs

@@ -13,7 +13,7 @@ namespace Tapeti.Flow
         /// Load the previously persisted flow states.
         /// </summary>
         /// <returns>A list of flow states, where the key is the unique Flow ID and the value is the deserialized T.</returns>
-        Task<IEnumerable<FlowRecord<T>>> GetStates<T>();
+        ValueTask<IEnumerable<FlowRecord<T>>> GetStates<T>();
 
         /// <summary>
         /// Stores a new flow state. Guaranteed to be run in a lock for the specified flow ID.
@@ -22,20 +22,20 @@ namespace Tapeti.Flow
         /// <param name="state">The flow state to be stored.</param>
         /// <param name="timestamp">The time when the flow was initially created.</param>
         /// <returns></returns>
-        Task CreateState<T>(Guid flowID, T state, DateTime timestamp);
+        ValueTask CreateState<T>(Guid flowID, T state, DateTime timestamp);
 
         /// <summary>
         /// Updates an existing flow state. Guaranteed to be run in a lock for the specified flow ID.
         /// </summary>
         /// <param name="flowID">The unique ID of the flow.</param>
         /// <param name="state">The flow state to be stored.</param>
-        Task UpdateState<T>(Guid flowID, T state);
+        ValueTask UpdateState<T>(Guid flowID, T state);
 
         /// <summary>
         /// Delete a flow state. Guaranteed to be run in a lock for the specified flow ID.
         /// </summary>
         /// <param name="flowID">The unique ID of the flow.</param>
-        Task DeleteState(Guid flowID);
+        ValueTask DeleteState(Guid flowID);
     }
 
 

Tapeti.Flow/IFlowStore.cs

@@ -17,19 +17,19 @@ namespace Tapeti.Flow
         /// If using an IFlowRepository that requires an update (such as creating tables) make
         /// sure it is called before calling Load.
         /// </summary>
-        Task Load();
+        ValueTask Load();
 
         /// <summary>
         /// Looks up the FlowID corresponding to a ContinuationID. For internal use.
         /// </summary>
         /// <param name="continuationID"></param>
-        Task<Guid?> FindFlowID(Guid continuationID);
+        ValueTask<Guid?> FindFlowID(Guid continuationID);
 
         /// <summary>
         /// Acquires a lock on the flow with the specified FlowID.
         /// </summary>
         /// <param name="flowID"></param>
-        Task<IFlowStateLock> LockFlowState(Guid flowID);
+        ValueTask<IFlowStateLock> LockFlowState(Guid flowID);
 
         /// <summary>
         /// Returns information about the currently active flows.
@@ -38,11 +38,10 @@ namespace Tapeti.Flow
         /// This is intended for monitoring purposes and should be treated as a snapshot.
         /// </remarks>
         /// <param name="minimumAge">The minimum age of the flow before it is included in the result. Set to TimeSpan.Zero to return all active flows.</param>
-        Task<IEnumerable<ActiveFlow>> GetActiveFlows(TimeSpan minimumAge);
+        ValueTask<IEnumerable<ActiveFlow>> GetActiveFlows(TimeSpan minimumAge);
     }
 
 
-    /// <inheritdoc />
     /// <summary>
     /// Represents a lock on the flow state, to provide thread safety.
     /// </summary>
@@ -56,19 +55,19 @@ namespace Tapeti.Flow
         /// <summary>
         /// Acquires a copy of the flow state.
         /// </summary>
-        Task<FlowState> GetFlowState();
+        ValueTask<FlowState?> GetFlowState();
 
         /// <summary>
         /// Stores the new flow state.
         /// </summary>
         /// <param name="flowState"></param>
         /// <param name="persistent"></param>
-        Task StoreFlowState(FlowState flowState, bool persistent);
+        ValueTask StoreFlowState(FlowState flowState, bool persistent);
 
         /// <summary>
         /// Disposes of the flow state corresponding to this Flow ID.
         /// </summary>
-        Task DeleteFlowState();
+        ValueTask DeleteFlowState();
     }
 
 

Tapeti.Flow/ReSharper/JetBrains.Annotations.cs

@@ -170,11 +170,11 @@ namespace JetBrains.Annotations
     {
         public PublicAPIAttribute() { }
 
-        public PublicAPIAttribute([NotNull] string comment)
+        public PublicAPIAttribute(string comment)
         {
             Comment = comment;
         }
 
-        [CanBeNull] public string Comment { get; }
+        public string? Comment { get; }
     }
 }

Tapeti.Flow/ResponseExpectedException.cs

@@ -2,7 +2,6 @@
 
 namespace Tapeti.Flow
 {
-    /// <inheritdoc />
     /// <summary>
     /// Raised when a response is expected to end a flow, but none was provided.
     /// </summary>

Tapeti.Flow/Tapeti.Flow.csproj

@@ -1,7 +1,7 @@
-<Project Sdk="Microsoft.NET.Sdk">
+<Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFramework>netstandard2.0</TargetFramework>
+    <TargetFrameworks>net6.0;net7.0</TargetFrameworks>
     <GenerateDocumentationFile>true</GenerateDocumentationFile>
     <Authors>Menno van Lavieren, Mark van Renswoude</Authors>
     <Company />
@@ -11,12 +11,19 @@
     <PackageProjectUrl>https://github.com/MvRens/Tapeti</PackageProjectUrl>
     <PackageIcon>Tapeti.Flow.png</PackageIcon>
     <Version>2.0.0</Version>
+    <LangVersion>9</LangVersion>
+    <Nullable>enable</Nullable>
   </PropertyGroup>
 
   <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug|AnyCPU'">
     <NoWarn>1701;1702</NoWarn>
   </PropertyGroup>
 
+  <PropertyGroup Condition="'$(TargetFramework)'!='netstandard2.0'">
+    <!-- Suppress 'Use switch expression' which requires language version 8 not available in .NET Standard 2.0 -->
+    <NoWarn>IDE0066</NoWarn>
+  </PropertyGroup>
+
   <ItemGroup>
     <ProjectReference Include="..\Tapeti\Tapeti.csproj" />
   </ItemGroup>
@@ -29,7 +36,7 @@
   </ItemGroup>
 
   <ItemGroup>
-    <PackageReference Include="Microsoft.SourceLink.GitHub" Version="1.0.0" PrivateAssets="All" />
+    <PackageReference Include="Microsoft.SourceLink.GitHub" Version="1.1.1" PrivateAssets="All" />
-    <PackageReference Include="Tapeti.Annotations" Version="3.0.0" />
+    <PackageReference Include="Tapeti.Annotations" Version="3.*-*" />
   </ItemGroup>
 </Project>

Tapeti.Flow/YieldPointException.cs

@@ -2,7 +2,6 @@
 
 namespace Tapeti.Flow
 {
-    /// <inheritdoc />
     /// <summary>
     /// Raised when an invalid yield point is returned.
     /// </summary>

Tapeti.Ninject/NinjectDependencyResolver.cs

@@ -4,7 +4,6 @@ using Ninject;
 
 namespace Tapeti.Ninject
 {
-    /// <inheritdoc />
     /// <summary>
     /// Dependency resolver and container implementation for Ninject.
     /// </summary>
@@ -49,7 +48,7 @@ namespace Tapeti.Ninject
             if (kernel.GetBindings(typeof(TService)).Any())
                 return;
 
-            kernel.Bind<TService>().ToMethod(context => factory());
+            kernel.Bind<TService>().ToMethod(_ => factory());
         }
 
 
@@ -77,7 +76,7 @@ namespace Tapeti.Ninject
             if (kernel.GetBindings(typeof(TService)).Any())
                 return;
 
-            kernel.Bind<TService>().ToMethod(context => factory()).InSingletonScope();
+            kernel.Bind<TService>().ToMethod(_ => factory()).InSingletonScope();
         }
 
 

Tapeti.Ninject/Tapeti.Ninject.csproj

@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFramework>netstandard2.0</TargetFramework>
+    <TargetFrameworks>net6.0;net7.0</TargetFrameworks>
     <GenerateDocumentationFile>true</GenerateDocumentationFile>
     <Authors>Mark van Renswoude</Authors>
     <Company />
@@ -11,10 +11,12 @@
     <PackageProjectUrl>https://github.com/MvRens/Tapeti</PackageProjectUrl>
     <PackageIcon>Tapeti.SimpleInjector.png</PackageIcon>
     <Version>2.0.0</Version>
+    <LangVersion>9</LangVersion>
+    <Nullable>enable</Nullable>
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="Ninject" Version="3.3.4" />
+    <PackageReference Include="Ninject" Version="3.*" />
   </ItemGroup>
 
   <ItemGroup>
@@ -29,6 +31,6 @@
   </ItemGroup>
 
   <ItemGroup>
-    <PackageReference Include="Microsoft.SourceLink.GitHub" Version="1.0.0" PrivateAssets="All"/>
+    <PackageReference Include="Microsoft.SourceLink.GitHub" Version="1.1.1" PrivateAssets="All" />
   </ItemGroup>
 </Project>

Tapeti.Serilog/Default/DiagnosticContext.cs

@@ -10,7 +10,7 @@ namespace Tapeti.Serilog.Default
     public class DiagnosticContext : IDiagnosticContext
     {
         private readonly global::Serilog.ILogger logger;
-        private readonly List<LogEventProperty> properties = new List<LogEventProperty>();
+        private readonly List<LogEventProperty> properties = new();
 
         
         /// <summary>

Tapeti.Serilog/Middleware/MessageHandlerLoggingBindingMiddleware.cs

@@ -43,7 +43,7 @@ namespace Tapeti.Serilog.Middleware
         }
 
 
-        private static object DiagnosticContextFactory(IMessageContext context)
+        private static object? DiagnosticContextFactory(IMessageContext context)
         {
             return context.TryGet<DiagnosticContextPayload>(out var diagnosticContextPayload)
                 ? diagnosticContextPayload.DiagnosticContext

Tapeti.Serilog/Middleware/MessageHandlerLoggingMessageMiddleware.cs

@@ -29,7 +29,7 @@ namespace Tapeti.Serilog.Middleware
         }
         
         /// <inheritdoc />
-        public async Task Handle(IMessageContext context, Func<Task> next)
+        public async ValueTask Handle(IMessageContext context, Func<ValueTask> next)
         {
             var logger = context.Config.DependencyResolver.Resolve<global::Serilog.ILogger>();
             
@@ -41,6 +41,7 @@ namespace Tapeti.Serilog.Middleware
             
             await next();
 
+
             stopwatch.Stop();
 
             

Tapeti.Serilog/Tapeti.Serilog.csproj

@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFramework>netstandard2.0</TargetFramework>
+    <TargetFrameworks>net6.0;net7.0</TargetFrameworks>
     <GenerateDocumentationFile>true</GenerateDocumentationFile>
     <Authors>Hans Mulder, Mark van Renswoude</Authors>
     <Company />
@@ -11,6 +11,8 @@
     <PackageProjectUrl>https://github.com/MvRens/Tapeti</PackageProjectUrl>
     <PackageIcon>Tapeti.Serilog.png</PackageIcon>
     <Version>2.0.0</Version>
+    <LangVersion>9</LangVersion>
+    <Nullable>enable</Nullable>
   </PropertyGroup>
 
   <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug|AnyCPU'">
@@ -18,7 +20,7 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="Serilog" Version="2.10.0" />
+    <PackageReference Include="Serilog" Version="2.*" />
   </ItemGroup>
 
   <ItemGroup>
@@ -33,6 +35,6 @@
   </ItemGroup>
 
   <ItemGroup>
-    <PackageReference Include="Microsoft.SourceLink.GitHub" Version="1.0.0" PrivateAssets="All" />
+    <PackageReference Include="Microsoft.SourceLink.GitHub" Version="1.1.1" PrivateAssets="All" />
   </ItemGroup>
 </Project>

Tapeti.Serilog/TapetiSeriLogger.cs

@@ -2,6 +2,7 @@
 using System.Collections.Generic;
 using System.Text;
 using Tapeti.Config;
+using Tapeti.Connection;
 using ISerilogLogger = Serilog.ILogger;
 
 // ReSharper disable UnusedMember.Global
@@ -86,7 +87,7 @@ namespace Tapeti.Serilog
         public void ConsumeException(Exception exception, IMessageContext messageContext, ConsumeResult consumeResult)
         {
             var message = new StringBuilder("Tapeti: exception in message handler");
-            var messageParams = new List<object>();
+            var messageParams = new List<object?>();
             
             var contextLogger = seriLogger
                 .ForContext("consumeResult", consumeResult)
@@ -129,10 +130,11 @@ namespace Tapeti.Serilog
         }
 
         /// <inheritdoc />
-        public void QueueExistsWarning(string queueName, Dictionary<string, string> arguments)
+        public void QueueExistsWarning(string queueName, IRabbitMQArguments? existingArguments, IRabbitMQArguments? arguments)
         {
-            seriLogger.Warning("Tapeti: durable queue {queueName} exists with incompatible x-arguments ({arguments}) and will not be redeclared, queue will be consumed as-is",
+            seriLogger.Warning("Tapeti: durable queue {queueName} exists with incompatible x-arguments ({existingArguments} vs. {arguments}) and will not be redeclared, queue will be consumed as-is",
                 queueName,
+                existingArguments,
                 arguments);
         }
 

Tapeti.SimpleInjector/SimpleInjectorDependencyResolver.cs

@@ -4,19 +4,18 @@ using SimpleInjector;
 
 namespace Tapeti.SimpleInjector
 {
-    /// <inheritdoc />
     /// <summary>
     /// Dependency resolver and container implementation for SimpleInjector.
     /// </summary>
     public class SimpleInjectorDependencyResolver : IDependencyContainer
     {
         private readonly Container container;
-        private readonly Lifestyle defaultsLifestyle;
+        private readonly Lifestyle? defaultsLifestyle;
-        private readonly Lifestyle controllersLifestyle;
+        private readonly Lifestyle? controllersLifestyle;
 
         /// <summary>
         /// </summary>
-        public SimpleInjectorDependencyResolver(Container container, Lifestyle defaultsLifestyle = null, Lifestyle controllersLifestyle = null)
+        public SimpleInjectorDependencyResolver(Container container, Lifestyle? defaultsLifestyle = null, Lifestyle? controllersLifestyle = null)
         {
             this.container = container;
             this.defaultsLifestyle = defaultsLifestyle;

Tapeti.SimpleInjector/Tapeti.SimpleInjector.csproj

@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFramework>netstandard2.0</TargetFramework>
+    <TargetFrameworks>net6.0;net7.0</TargetFrameworks>
     <GenerateDocumentationFile>true</GenerateDocumentationFile>
     <Authors>Mark van Renswoude</Authors>
     <Company />
@@ -11,7 +11,8 @@
     <PackageProjectUrl>https://github.com/MvRens/Tapeti</PackageProjectUrl>
     <PackageIcon>Tapeti.SimpleInjector.png</PackageIcon>
     <Version>2.0.0</Version>
-    <Version>2.0.0</Version>
+    <LangVersion>9</LangVersion>
+    <Nullable>enable</Nullable>
   </PropertyGroup>
 
   <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug|AnyCPU'">
@@ -19,7 +20,7 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="SimpleInjector" Version="5.3.0" />
+    <PackageReference Include="SimpleInjector" Version="5.*" />
   </ItemGroup>
 
   <ItemGroup>
@@ -34,6 +35,6 @@
   </ItemGroup>
 
   <ItemGroup>
-    <PackageReference Include="Microsoft.SourceLink.GitHub" Version="1.0.0" PrivateAssets="All"/>
+    <PackageReference Include="Microsoft.SourceLink.GitHub" Version="1.1.1" PrivateAssets="All" />
   </ItemGroup>
 </Project>

Tapeti.Tests/Client/RabbitMQFixture.cs

@@ -0,0 +1,79 @@
+using System;
+using System.Threading.Tasks;
+using Docker.DotNet;
+using Docker.DotNet.Models;
+using DotNet.Testcontainers.Builders;
+using DotNet.Testcontainers.Configurations;
+using DotNet.Testcontainers.Containers;
+using Xunit;
+
+namespace Tapeti.Tests.Client
+{
+    [CollectionDefinition(Name)]
+    public sealed class RabbitMQCollection : ICollectionFixture<RabbitMQFixture>
+    {
+        public const string Name = "RabbitMQ";
+    }
+
+
+    public sealed class RabbitMQFixture : IAsyncLifetime
+    {
+        public static string RabbitMQUsername => "tapetitests";
+        public static string RabbitMQPassword => "topsecret1234";
+
+        public ushort RabbitMQPort { get; private set; }
+        public ushort RabbitMQManagementPort { get; private set; }
+
+
+        private TestcontainerMessageBroker? testcontainers;
+
+        private const int DefaultRabbitMQPort = 5672;
+        private const int DefaultRabbitMQManagementPort = 15672;
+
+
+
+        private const string ImageName = "rabbitmq";
+        private const string ImageTag = "3.11.3-alpine";
+
+
+        public async Task InitializeAsync()
+        {
+            // Testcontainers does not seem to pull the image the first time.
+            // I didn't get it to work, even using WithImagePullPolicy from the latest beta.
+            // Note: running it the first time can take a while.
+            var client = new DockerClientConfiguration().CreateClient();
+            await client.Images.CreateImageAsync(
+                new ImagesCreateParameters
+                {
+                    FromImage = ImageName,
+                    Tag = ImageTag
+                },
+                null,
+                new Progress<JSONMessage>());
+
+            // If you get a "Sequence contains no elements" error here: make sure Docker Desktop is running
+            var testcontainersBuilder = new TestcontainersBuilder<RabbitMqTestcontainer>()
+                .WithMessageBroker(new RabbitMqTestcontainerConfiguration($"{ImageName}:{ImageTag}")
+                {
+                    Username = RabbitMQUsername,
+                    Password = RabbitMQPassword
+                })
+                .WithExposedPort(DefaultRabbitMQManagementPort)
+                .WithPortBinding(0, DefaultRabbitMQManagementPort);
+
+            testcontainers = testcontainersBuilder.Build();
+
+            await testcontainers.StartAsync();
+
+            RabbitMQPort = testcontainers.GetMappedPublicPort(DefaultRabbitMQPort);
+            RabbitMQManagementPort = testcontainers.GetMappedPublicPort(DefaultRabbitMQManagementPort);
+        }
+
+
+        public async Task DisposeAsync()
+        {
+            if (testcontainers != null)
+                await testcontainers.DisposeAsync();
+        }
+    }
+}

Tapeti.Tests/Client/TapetiClientTests.cs

@@ -0,0 +1,116 @@
+using System.Text;
+using System.Threading;
+using System.Threading.Tasks;
+using FluentAssertions;
+using Tapeti.Connection;
+using Tapeti.Default;
+using Tapeti.Exceptions;
+using Tapeti.Tests.Mock;
+using Xunit;
+using Xunit.Abstractions;
+
+namespace Tapeti.Tests.Client
+{
+    [Collection(RabbitMQCollection.Name)]
+    [Trait("Category", "Requires Docker")]
+    public class TapetiClientTests : IAsyncLifetime
+    {
+        private readonly RabbitMQFixture fixture;
+        private readonly MockDependencyResolver dependencyResolver = new();
+
+        private TapetiClient client = null!;
+
+
+        public TapetiClientTests(RabbitMQFixture fixture, ITestOutputHelper testOutputHelper)
+        {
+            this.fixture = fixture;
+
+            dependencyResolver.Set<ILogger>(new MockLogger(testOutputHelper));
+        }
+
+
+        public Task InitializeAsync()
+        {
+            client = CreateClient();
+
+            return Task.CompletedTask;
+        }
+
+
+        public async Task DisposeAsync()
+        {
+            await client.Close();
+        }
+
+
+
+        [Fact]
+        public void Fixture()
+        {
+            fixture.RabbitMQPort.Should().BeGreaterThan(0);
+            fixture.RabbitMQManagementPort.Should().BeGreaterThan(0);
+        }
+
+
+        [Fact]
+        public async Task DynamicQueueDeclareNoPrefix()
+        {
+            var queueName = await client.DynamicQueueDeclare(null, null, CancellationToken.None);
+            queueName.Should().NotBeNullOrEmpty();
+        }
+
+
+        [Fact]
+        public async Task DynamicQueueDeclarePrefix()
+        {
+            var queueName = await client.DynamicQueueDeclare("dynamicprefix", null, CancellationToken.None);
+            queueName.Should().StartWith("dynamicprefix");
+        }
+
+
+        [Fact]
+        public async Task PublishHandleOverflow()
+        {
+            var queue1 = await client.DynamicQueueDeclare(null, new RabbitMQArguments
+            {
+                { "x-max-length", 5 },
+                { "x-overflow", "reject-publish" }
+            }, CancellationToken.None);
+
+            var queue2 = await client.DynamicQueueDeclare(null, null, CancellationToken.None);
+
+            var body = Encoding.UTF8.GetBytes("Hello world!");
+            var properties = new MessageProperties();
+
+
+            for (var i = 0; i < 5; i++)
+                await client.Publish(body, properties, null, queue1, true);
+
+
+            var publishOverMaxLength = () => client.Publish(body, properties, null, queue1, true);
+            await publishOverMaxLength.Should().ThrowAsync<NackException>();
+
+            // The channel should recover and allow further publishing
+            await client.Publish(body, properties, null, queue2, true);
+        }
+
+
+        // TODO test the other methods
+
+
+        private TapetiClient CreateClient()
+        {
+            return new TapetiClient(
+                new TapetiConfig.Config(dependencyResolver),
+                new TapetiConnectionParams
+                {
+                    HostName = "127.0.0.1",
+                    Port = fixture.RabbitMQPort,
+                    ManagementPort = fixture.RabbitMQManagementPort,
+                    Username = RabbitMQFixture.RabbitMQUsername,
+                    Password = RabbitMQFixture.RabbitMQPassword,
+                    PrefetchCount = 50
+                });
+        }
+    }
+}

Tapeti.Tests/Config/BaseControllerTest.cs

@@ -0,0 +1,29 @@
+using JetBrains.Annotations;
+using Tapeti.Config;
+using Tapeti.Tests.Mock;
+
+namespace Tapeti.Tests.Config
+{
+    public class BaseControllerTest
+    {
+        protected readonly MockDependencyResolver DependencyResolver = new();
+
+
+        protected ITapetiConfig GetControllerConfig<[MeansImplicitUse(ImplicitUseTargetFlags.WithMembers)] T>() where T : class
+        {
+            var configBuilder = new TapetiConfig(DependencyResolver);
+
+            configBuilder.EnableDeclareDurableQueues();
+            configBuilder.RegisterController(typeof(T));
+            var config = configBuilder.Build();
+
+            return config;
+        }
+
+
+        protected ITapetiConfigBindings GetControllerBindings<[MeansImplicitUse(ImplicitUseTargetFlags.WithMembers)] T>() where T : class
+        {
+            return GetControllerConfig<T>().Bindings;
+        }
+    }
+}

Tapeti.Tests/Config/QueueArgumentsTest.cs

@@ -0,0 +1,210 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading;
+using System.Threading.Tasks;
+using FluentAssertions;
+using FluentAssertions.Execution;
+using Moq;
+using Tapeti.Annotations;
+using Tapeti.Config;
+using Tapeti.Connection;
+using Xunit;
+
+namespace Tapeti.Tests.Config
+{
+    internal static class UTF8StringExtensions
+    {
+        public static string AsUTF8String(this object value)
+        {
+            value.Should().BeOfType<byte[]>();
+            return Encoding.UTF8.GetString((byte[])value);
+        }
+    }
+
+
+    public class QueueArgumentsTest : BaseControllerTest
+    {
+        private static readonly MockRepository MoqRepository = new(MockBehavior.Strict);
+
+        private readonly Mock<ITapetiClient> client;
+        private readonly Dictionary<string, IRabbitMQArguments> declaredQueues = new();
+
+
+        public QueueArgumentsTest()
+        {
+            client = MoqRepository.Create<ITapetiClient>();
+            var routingKeyStrategy = MoqRepository.Create<IRoutingKeyStrategy>();
+            var exchangeStrategy = MoqRepository.Create<IExchangeStrategy>();
+
+            DependencyResolver.Set(routingKeyStrategy.Object);
+            DependencyResolver.Set(exchangeStrategy.Object);
+
+
+            routingKeyStrategy
+                .Setup(s => s.GetRoutingKey(typeof(TestMessage1)))
+                .Returns("testmessage1");
+
+            routingKeyStrategy
+                .Setup(s => s.GetRoutingKey(typeof(TestMessage2)))
+                .Returns("testmessage2");
+
+            exchangeStrategy
+                .Setup(s => s.GetExchange(It.IsAny<Type>()))
+                .Returns("exchange");
+
+            var queue = 0;
+            client
+                .Setup(c => c.DynamicQueueDeclare(null, It.IsAny<IRabbitMQArguments>(), It.IsAny<CancellationToken>()))
+                .Callback((string _, IRabbitMQArguments arguments, CancellationToken _) =>
+                {
+                    queue++;
+                    declaredQueues.Add($"queue-{queue}", arguments);
+                })
+                .ReturnsAsync(() => $"queue-{queue}");
+
+            client
+                .Setup(c => c.DurableQueueDeclare(It.IsAny<string>(), It.IsAny<IEnumerable<QueueBinding>>(), It.IsAny<IRabbitMQArguments>(), It.IsAny<CancellationToken>()))
+                .Callback((string queueName, IEnumerable<QueueBinding> _, IRabbitMQArguments arguments, CancellationToken _) =>
+                {
+                    declaredQueues.Add(queueName, arguments);
+                })
+                .Returns(Task.CompletedTask);
+
+
+            client
+                .Setup(c => c.DynamicQueueBind(It.IsAny<string>(), It.IsAny<QueueBinding>(), It.IsAny<CancellationToken>()))
+                .Returns(Task.CompletedTask);
+        }
+
+
+        [Fact]
+        public async Task SingleQueueArguments()
+        {
+            var config = GetControllerConfig<TestController>();
+
+            var binding1 = config.Bindings.Single(b => b is IControllerMethodBinding cmb && cmb.Method.Name == "HandleMessage1");
+            binding1.Should().NotBeNull();
+
+            var binding2 = config.Bindings.Single(b => b is IControllerMethodBinding cmb && cmb.Method.Name == "HandleMessage2");
+            binding2.Should().NotBeNull();
+
+
+
+            var subscriber = new TapetiSubscriber(() => client.Object, config);
+            await subscriber.ApplyBindings();
+
+
+            declaredQueues.Should().HaveCount(1);
+            var arguments = declaredQueues["queue-1"];
+
+            arguments.Should().ContainKey("x-custom").WhoseValue.AsUTF8String().Should().Be("custom value");
+            arguments.Should().ContainKey("x-another").WhoseValue.Should().Be(true);
+            arguments.Should().ContainKey("x-max-length").WhoseValue.Should().Be(100);
+            arguments.Should().ContainKey("x-max-length-bytes").WhoseValue.Should().Be(100000);
+            arguments.Should().ContainKey("x-message-ttl").WhoseValue.Should().Be(4269);
+            arguments.Should().ContainKey("x-overflow").WhoseValue.AsUTF8String().Should().Be("reject-publish");
+        }
+
+
+        [Fact]
+        public async Task ConflictingDynamicQueueArguments()
+        {
+            var config = GetControllerConfig<ConflictingArgumentsTestController>();
+
+            var subscriber = new TapetiSubscriber(() => client.Object, config);
+            await subscriber.ApplyBindings();
+
+            declaredQueues.Should().HaveCount(2);
+
+            var arguments1 = declaredQueues["queue-1"];
+            arguments1.Should().ContainKey("x-max-length").WhoseValue.Should().Be(100);
+
+            var arguments2 = declaredQueues["queue-2"];
+            arguments2.Should().ContainKey("x-max-length-bytes").WhoseValue.Should().Be(100000);
+        }
+
+
+        [Fact]
+        public async Task ConflictingDurableQueueArguments()
+        {
+            var config = GetControllerConfig<ConflictingArgumentsDurableQueueTestController>();
+
+            var testApplyBindings = () =>
+            {
+                var subscriber = new TapetiSubscriber(() => client.Object, config);
+                return subscriber.ApplyBindings();
+            };
+
+            using (new AssertionScope())
+            {
+                await testApplyBindings.Should().ThrowAsync<TopologyConfigurationException>();
+                declaredQueues.Should().HaveCount(0);
+            }
+        }
+
+        
+        // ReSharper disable all
+        #pragma warning disable
+
+        private class TestMessage1
+        {
+        }
+
+
+        private class TestMessage2
+        {
+        }
+
+
+        [DynamicQueue]
+        [QueueArguments("x-custom", "custom value", "x-another", true, MaxLength = 100, MaxLengthBytes = 100000, MessageTTL = 4269, Overflow = RabbitMQOverflow.RejectPublish)]
+        private class TestController
+        {
+            public void HandleMessage1(TestMessage1 message)
+            {
+            }
+
+
+            public void HandleMessage2(TestMessage2 message)
+            {
+            }
+        }
+
+
+        [DynamicQueue]
+        [QueueArguments(MaxLength = 100)]
+        private class ConflictingArgumentsTestController
+        {
+            public void HandleMessage1(TestMessage1 message)
+            {
+            }
+
+
+            [QueueArguments(MaxLengthBytes = 100000)]
+            public void HandleMessage2(TestMessage1 message)
+            {
+            }
+        }
+
+
+        [DurableQueue("durable")]
+        [QueueArguments(MaxLength = 100)]
+        private class ConflictingArgumentsDurableQueueTestController
+        {
+            public void HandleMessage1(TestMessage1 message)
+            {
+            }
+
+
+            [QueueArguments(MaxLengthBytes = 100000)]
+            public void HandleMessage2(TestMessage1 message)
+            {
+            }
+        }
+
+        #pragma warning restore
+        // ReSharper restore all
+    }
+}

Tapeti.Tests/Config/SimpleControllerTest.cs

@@ -0,0 +1,54 @@
+using System.Linq;
+using FluentAssertions;
+using Tapeti.Annotations;
+using Tapeti.Config;
+using Xunit;
+
+namespace Tapeti.Tests.Config
+{
+    public class SimpleControllerTest : BaseControllerTest
+    {
+        [Fact]
+        public void RegisterController()
+        {
+            var bindings = GetControllerBindings<TestController>();
+            bindings.Should().HaveCount(2);
+
+            var handleSimpleMessageBinding = bindings.Single(b => b is IControllerMethodBinding cmb &&
+                                                                  cmb.Controller == typeof(TestController) &&
+                                                                  cmb.Method.Name == "HandleSimpleMessage");
+            handleSimpleMessageBinding.QueueType.Should().Be(QueueType.Dynamic);
+
+
+            var handleSimpleMessageStaticBinding = bindings.Single(b => b is IControllerMethodBinding cmb &&
+                                                                   cmb.Controller == typeof(TestController) &&
+                                                                   cmb.Method.Name == "HandleSimpleMessageStatic");
+            handleSimpleMessageStaticBinding.QueueType.Should().Be(QueueType.Dynamic);
+
+        }
+
+
+        // ReSharper disable all
+        #pragma warning disable
+
+        private class TestMessage
+        {
+        }
+
+
+        [DynamicQueue]
+        private class TestController
+        {
+            public void HandleSimpleMessage(TestMessage message)
+            {
+            }
+
+            public static void HandleSimpleMessageStatic(TestMessage message)
+            {
+            }
+        }
+
+        #pragma warning restore
+        // ReSharper restore all
+    }
+}

Tapeti.Tests/Helpers/ExpressionInvokerTest.cs

@@ -0,0 +1,227 @@
+using System.Collections.Generic;
+using System.Linq;
+using System.Runtime.CompilerServices;
+using FluentAssertions;
+using Tapeti.Helpers;
+using Xunit;
+
+namespace Tapeti.Tests.Helpers
+{
+    public class ExpressionInvokerTest
+    {
+        [Fact]
+        public void InstanceMethodVoidNoParameters()
+        {
+            const string methodName = nameof(InvokeTarget.InstanceMethodVoidNoParameters);
+            var invoker = InvokerFor(methodName);
+
+            var target = new InvokeTarget();
+            invoker.Invoke(target);
+            
+            target.Verify(methodName);
+        }
+
+
+        [Fact]
+        public void InstanceMethodReturnValueNoParameters()
+        {
+            const string methodName = nameof(InvokeTarget.InstanceMethodReturnValueNoParameters);
+            var invoker = InvokerFor(methodName);
+
+            var target = new InvokeTarget();
+            var returnValue = invoker.Invoke(target);
+
+            target.Verify(methodName);
+            returnValue.Should().Be("Hello world!");
+        }
+
+
+        [Fact]
+        public void InstanceMethodVoidParameters()
+        {
+            const string methodName = nameof(InvokeTarget.InstanceMethodVoidParameters);
+            var invoker = InvokerFor(methodName);
+
+            var target = new InvokeTarget();
+            invoker.Invoke(target, 42);
+
+            target.Verify(methodName, "42");
+        }
+
+
+        [Fact]
+        public void InstanceMethodReturnValueParameters()
+        {
+            const string methodName = nameof(InvokeTarget.InstanceMethodReturnValueParameters);
+            var invoker = InvokerFor(methodName);
+
+            var target = new InvokeTarget();
+            var returnValue = invoker.Invoke(target, new byte[] { 42, 69 });
+
+            target.Verify(methodName, "42,69");
+            returnValue.Should().Be(true);
+        }
+
+
+        [Fact]
+        public void StaticMethodVoidNoParameters()
+        {
+            InvokeTarget.ResetStatic();
+
+            const string methodName = nameof(InvokeTarget.StaticMethodVoidNoParameters);
+            var invoker = InvokerFor(methodName);
+
+            invoker.Invoke(null);
+
+            InvokeTarget.VerifyStatic(methodName);
+        }
+
+
+        [Fact]
+        public void StaticMethodReturnValueNoParameters()
+        {
+            InvokeTarget.ResetStatic();
+
+            const string methodName = nameof(InvokeTarget.StaticMethodReturnValueNoParameters);
+            var invoker = InvokerFor(methodName);
+
+            var returnValue = invoker.Invoke(null);
+
+            InvokeTarget.VerifyStatic(methodName);
+            returnValue.Should().Be("Hello world!");
+        }
+
+
+        [Fact]
+        public void StaticMethodVoidParameters()
+        {
+            InvokeTarget.ResetStatic();
+
+            const string methodName = nameof(InvokeTarget.StaticMethodVoidParameters);
+            var invoker = InvokerFor(methodName);
+
+            invoker.Invoke(null, 42);
+
+            InvokeTarget.VerifyStatic(methodName, "42");
+        }
+
+
+        [Fact]
+        public void StaticMethodReturnValueParameters()
+        {
+            InvokeTarget.ResetStatic();
+
+            const string methodName = nameof(InvokeTarget.StaticMethodReturnValueParameters);
+            var invoker = InvokerFor(methodName);
+
+            var returnValue = invoker.Invoke(null, new byte[] { 42, 69 });
+
+            InvokeTarget.VerifyStatic(methodName, "42,69");
+            returnValue.Should().Be(true);
+        }
+
+
+        private static ExpressionInvoke InvokerFor(string invokeTargetMethodName)
+        {
+            var method = typeof(InvokeTarget).GetMethod(invokeTargetMethodName);
+            return method!.CreateExpressionInvoke();
+        }
+
+
+
+        // ReSharper disable ParameterHidesMember
+        private class InvokeTarget
+        {
+            private static string? staticMethodName;
+            private static string? staticParameters;
+
+            private string? methodName;
+            private string? parameters;
+
+
+            public void InstanceMethodVoidNoParameters()
+            {
+                MethodCalled();
+            }
+
+            public string InstanceMethodReturnValueNoParameters()
+            {
+                MethodCalled();
+                return "Hello world!";
+            }
+
+            public void InstanceMethodVoidParameters(int answer)
+            {
+                MethodCalled(answer.ToString());
+            }
+
+            public bool InstanceMethodReturnValueParameters(IEnumerable<byte> values)
+            {
+                MethodCalled(string.Join(',', values.Select(v => v.ToString())));
+                return true;
+            }
+
+
+            public static void StaticMethodVoidNoParameters()
+            {
+                StaticMethodCalled();
+            }
+
+            public static string StaticMethodReturnValueNoParameters()
+            {
+                StaticMethodCalled();
+                return "Hello world!";
+            }
+
+            public static void StaticMethodVoidParameters(int answer)
+            {
+                StaticMethodCalled(answer.ToString());
+            }
+
+            public static bool StaticMethodReturnValueParameters(IEnumerable<byte> values)
+            {
+                StaticMethodCalled(string.Join(',', values.Select(v => v.ToString())));
+                return true;
+            }
+
+
+            private void MethodCalled(string parameters = "", [CallerMemberName]string methodName = "")
+            {
+                this.methodName.Should().BeNull();
+                this.methodName = methodName;
+                this.parameters = parameters;
+
+            }
+
+
+            public static void ResetStatic()
+            {
+                staticMethodName = null;
+                staticParameters = null;
+            }
+
+
+            private static void StaticMethodCalled(string parameters = "", [CallerMemberName] string methodName = "")
+            {
+                staticMethodName.Should().BeNull();
+                staticMethodName = methodName;
+                staticParameters = parameters;
+            }
+
+
+
+            public void Verify(string methodName, string parameters = "")
+            {
+                this.methodName.Should().Be(methodName);
+                this.parameters.Should().Be(parameters);
+            }
+
+
+            public static void VerifyStatic(string methodName, string parameters = "")
+            {
+                staticMethodName.Should().Be(methodName);
+                staticParameters.Should().Be(parameters);
+            }
+        }
+    }
+}

Tapeti.Tests/Mock/MockDependencyResolver.cs

@@ -0,0 +1,28 @@
+using System;
+using System.Collections.Generic;
+
+namespace Tapeti.Tests.Mock
+{
+    public class MockDependencyResolver : IDependencyResolver
+    {
+        private readonly Dictionary<Type, object> container = new();
+
+
+        public void Set<TInterface>(TInterface instance) where TInterface : class
+        {
+            container.Add(typeof(TInterface), instance);
+        }
+
+
+        public T Resolve<T>() where T : class
+        {
+            return (T)Resolve(typeof(T));
+        }
+
+
+        public object Resolve(Type type)
+        {
+            return container[type];
+        }
+    }
+}

Tapeti.Tests/Mock/MockLogger.cs

@@ -0,0 +1,98 @@
+using System;
+using System.Text;
+using Tapeti.Config;
+using Tapeti.Connection;
+using Xunit.Abstractions;
+
+namespace Tapeti.Tests.Mock
+{
+    internal class MockLogger : IBindingLogger
+    {
+        private readonly ITestOutputHelper testOutputHelper;
+
+
+        public MockLogger(ITestOutputHelper testOutputHelper)
+        {
+            this.testOutputHelper = testOutputHelper;
+        }
+
+
+        public void Connect(IConnectContext connectContext)
+        {
+            testOutputHelper.WriteLine($"{(connectContext.IsReconnect ? "Reconnecting" : "Connecting")} to {connectContext.ConnectionParams.HostName}:{connectContext.ConnectionParams.Port}{connectContext.ConnectionParams.VirtualHost}");
+        }
+
+        public void ConnectFailed(IConnectFailedContext connectContext)
+        {
+            testOutputHelper.WriteLine($"Connection failed: {connectContext.Exception}");
+        }
+
+        public void ConnectSuccess(IConnectSuccessContext connectContext)
+        {
+            testOutputHelper.WriteLine($"{(connectContext.IsReconnect ? "Reconnected" : "Connected")} using local port {connectContext.LocalPort}");
+        }
+
+        public void Disconnect(IDisconnectContext disconnectContext)
+        {
+            testOutputHelper.WriteLine($"Connection closed: {(!string.IsNullOrEmpty(disconnectContext.ReplyText) ? disconnectContext.ReplyText : "<no reply text>")} (reply code: {disconnectContext.ReplyCode})");
+        }
+
+        public void ConsumeException(Exception exception, IMessageContext messageContext, ConsumeResult consumeResult)
+        {
+            testOutputHelper.WriteLine(exception.Message);
+        }
+
+        public void QueueDeclare(string queueName, bool durable, bool passive)
+        {
+            testOutputHelper.WriteLine(passive
+                ? $"Verifying durable queue {queueName}"
+                : $"Declaring {(durable ? "durable" : "dynamic")} queue {queueName}");
+        }
+
+        public void QueueExistsWarning(string queueName, IRabbitMQArguments? existingArguments, IRabbitMQArguments? arguments)
+        {
+            testOutputHelper.WriteLine($"[Tapeti] Durable queue {queueName} exists with incompatible x-arguments ({GetArgumentsText(existingArguments)} vs. {GetArgumentsText(arguments)}) and will not be redeclared, queue will be consumed as-is");
+        }
+
+
+        private static string GetArgumentsText(IRabbitMQArguments? arguments)
+        {
+            if (arguments == null || arguments.Count == 0)
+                return "empty";
+
+            var argumentsText = new StringBuilder();
+            foreach (var pair in arguments)
+            {
+                if (argumentsText.Length > 0)
+                    argumentsText.Append(", ");
+
+                argumentsText.Append($"{pair.Key} = {pair.Value}");
+            }
+
+            return argumentsText.ToString();
+        }
+
+
+        public void QueueBind(string queueName, bool durable, string exchange, string routingKey)
+        {
+            testOutputHelper.WriteLine($"Binding {queueName} to exchange {exchange} with routing key {routingKey}");
+        }
+
+        public void QueueUnbind(string queueName, string exchange, string routingKey)
+        {
+            testOutputHelper.WriteLine($"Removing binding for {queueName} to exchange {exchange} with routing key {routingKey}");
+        }
+
+        public void ExchangeDeclare(string exchange)
+        {
+            testOutputHelper.WriteLine($"Declaring exchange {exchange}");
+        }
+
+        public void QueueObsolete(string queueName, bool deleted, uint messageCount)
+        {
+            testOutputHelper.WriteLine(deleted
+                ? $"Obsolete queue was deleted: {queueName}"
+                : $"Obsolete queue bindings removed: {queueName}, {messageCount} messages remaining");
+        }
+    }
+}

Tapeti.Tests/Tapeti.Tests.csproj

@@ -1,7 +1,8 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFramework>net5.0</TargetFramework>
+    <TargetFrameworks>net6.0;net7.0</TargetFrameworks>
+    <Nullable>enable</Nullable>
   </PropertyGroup>
 
   <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug|AnyCPU'">
@@ -9,10 +10,13 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="FluentAssertions" Version="5.10.3" />
+    <PackageReference Include="FluentAssertions" Version="6.8.0" />
-    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="16.10.0" />
+    <PackageReference Include="JetBrains.Annotations" Version="2022.3.1" />
-    <PackageReference Include="xunit" Version="2.4.1" />
+    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.4.0" />
-    <PackageReference Include="xunit.runner.visualstudio" Version="2.4.3">
+    <PackageReference Include="Moq" Version="4.18.2" />
+    <PackageReference Include="Testcontainers" Version="2.2.0" />
+    <PackageReference Include="xunit" Version="2.4.2" />
+    <PackageReference Include="xunit.runner.visualstudio" Version="2.4.5">
       <PrivateAssets>all</PrivateAssets>
       <IncludeAssets>runtime; build; native; contentfiles; analyzers</IncludeAssets>
     </PackageReference>
@@ -22,8 +26,4 @@
     <ProjectReference Include="..\Tapeti\Tapeti.csproj" />
   </ItemGroup>
 
-  <ItemGroup>
-    <Folder Include="Core\" />
-  </ItemGroup>
-
 </Project>

Tapeti.Transient/ConfigExtensions.cs

@@ -1,6 +1,8 @@
 using System;
 using Tapeti.Config;
 
+// ReSharper disable UnusedMember.Global
+
 namespace Tapeti.Transient
 {
     /// <summary>

Tapeti.Transient/ITransientPublisher.cs

@@ -15,6 +15,6 @@ namespace Tapeti.Transient
         /// <param name="request"></param>
         /// <typeparam name="TRequest"></typeparam>
         /// <typeparam name="TResponse"></typeparam>
-        Task<TResponse> RequestResponse<TRequest, TResponse>(TRequest request);
+        Task<TResponse> RequestResponse<TRequest, TResponse>(TRequest request) where TRequest : class where TResponse : class;
     }
 }

Tapeti.Transient/Tapeti.Transient.csproj

@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFramework>netstandard2.0</TargetFramework>
+    <TargetFrameworks>net6.0;net7.0</TargetFrameworks>
     <GenerateDocumentationFile>true</GenerateDocumentationFile>
     <Authors>Menno van Lavieren, Mark van Renswoude</Authors>
     <Company />
@@ -11,6 +11,8 @@
     <PackageProjectUrl>https://github.com/MvRens/Tapeti</PackageProjectUrl>
     <PackageIcon>Tapeti.Flow.png</PackageIcon>
     <Version>2.0.0</Version>
+    <LangVersion>9</LangVersion>
+    <Nullable>enable</Nullable>
   </PropertyGroup>
 
   <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug|AnyCPU'">
@@ -29,6 +31,6 @@
   </ItemGroup>
 
   <ItemGroup>
-    <PackageReference Include="Microsoft.SourceLink.GitHub" Version="1.0.0" PrivateAssets="All"/>
+    <PackageReference Include="Microsoft.SourceLink.GitHub" Version="1.1.1" PrivateAssets="All" />
   </ItemGroup>
 </Project>

Tapeti.Transient/TransientExtension.cs

@@ -1,5 +1,6 @@
 using System;
 using System.Collections.Generic;
+using System.Linq;
 using Tapeti.Config;
 
 namespace Tapeti.Transient
@@ -31,7 +32,7 @@ namespace Tapeti.Transient
         /// <inheritdoc />
         public IEnumerable<object> GetMiddleware(IDependencyResolver dependencyResolver)
         {
-            return null;
+            return Enumerable.Empty<object>();
         }
 
 

Tapeti.Transient/TransientGenericBinding.cs

@@ -4,7 +4,6 @@ using Tapeti.Config;
 
 namespace Tapeti.Transient
 {
-    /// <inheritdoc />
     /// <summary>
     /// Implements a binding for transient request response messages.
     /// Register this binding using the WithTransient config extension method.
@@ -15,10 +14,10 @@ namespace Tapeti.Transient
         private readonly string dynamicQueuePrefix;
 
         /// <inheritdoc />
-        public string QueueName { get; private set; }
+        public string? QueueName { get; private set; }
 
         /// <inheritdoc />
-        public QueueType QueueType => QueueType.Dynamic;
+        public QueueType? QueueType => Config.QueueType.Dynamic;
 
 
         /// <summary>
@@ -31,9 +30,9 @@ namespace Tapeti.Transient
 
 
         /// <inheritdoc />
-        public async Task Apply(IBindingTarget target)
+        public async ValueTask Apply(IBindingTarget target)
         {
-            QueueName = await target.BindDynamicDirect(dynamicQueuePrefix);
+            QueueName = await target.BindDynamicDirect(dynamicQueuePrefix, null);
             router.TransientResponseQueueName = QueueName;
         }
 
@@ -46,17 +45,17 @@ namespace Tapeti.Transient
 
 
         /// <inheritdoc />
-        public Task Invoke(IMessageContext context)
+        public ValueTask Invoke(IMessageContext context)
         {
             router.HandleMessage(context);
-            return Task.CompletedTask;
+            return default;
         }
 
 
         /// <inheritdoc />
-        public Task Cleanup(IMessageContext context, ConsumeResult consumeResult)
+        public ValueTask Cleanup(IMessageContext context, ConsumeResult consumeResult)
         {
-            return Task.CompletedTask;
+            return default;
         }
     }
 }

Tapeti.Transient/TransientPublisher.cs

@@ -2,7 +2,6 @@
 
 namespace Tapeti.Transient
 {
-    /// <inheritdoc />
     /// <summary>
     /// Default implementation of ITransientPublisher
     /// </summary>
@@ -22,7 +21,7 @@ namespace Tapeti.Transient
 
 
         /// <inheritdoc />
-        public async Task<TResponse> RequestResponse<TRequest, TResponse>(TRequest request)
+        public async Task<TResponse> RequestResponse<TRequest, TResponse>(TRequest request) where TRequest : class where TResponse : class
         {
             return (TResponse)await router.RequestResponse(publisher, request);
         }

Tapeti.Transient/TransientRouter.cs

@@ -13,12 +13,12 @@ namespace Tapeti.Transient
     internal class TransientRouter
     {
         private readonly int defaultTimeoutMs;
-        private readonly ConcurrentDictionary<Guid, TaskCompletionSource<object>> map = new ConcurrentDictionary<Guid, TaskCompletionSource<object>>();
+        private readonly ConcurrentDictionary<Guid, TaskCompletionSource<object>> map = new();
 
         /// <summary>
         /// The generated name of the dynamic queue to which responses should be sent.
         /// </summary>
-        public string TransientResponseQueueName { get; set; }
+        public string? TransientResponseQueueName { get; set; }
 
 
         /// <summary>
@@ -41,7 +41,12 @@ namespace Tapeti.Transient
             if (!Guid.TryParse(context.Properties.CorrelationId, out var continuationID))
                 return;
 
-            if (map.TryRemove(continuationID, out var tcs))
+            if (!map.TryRemove(continuationID, out var tcs)) 
+                return;
+
+            if (context.Message == null)
+                throw new InvalidOperationException();
+
             tcs.TrySetResult(context.Message);
         }
 
@@ -55,7 +60,7 @@ namespace Tapeti.Transient
         public async Task<object> RequestResponse(IPublisher publisher, object request)
         {
             var correlation = Guid.NewGuid();
-            var tcs = map.GetOrAdd(correlation, c => new TaskCompletionSource<object>());
+            var tcs = map.GetOrAdd(correlation, _ => new TaskCompletionSource<object>());
 
             try
             {
@@ -72,20 +77,22 @@ namespace Tapeti.Transient
             {
                 // Simple cleanup of the task and map dictionary.
                 if (map.TryRemove(correlation, out tcs))
-                    tcs.TrySetResult(null);
+                    tcs.TrySetResult(null!);
 
                 throw;
             }
 
-            using (new Timer(TimeoutResponse, tcs, defaultTimeoutMs, -1))
+            await using (new Timer(TimeoutResponse, tcs, defaultTimeoutMs, -1))
             {
                 return await tcs.Task;
             }
         }
 
 
-        private void TimeoutResponse(object tcs)
+        private void TimeoutResponse(object? tcs)
         {
+            ArgumentNullException.ThrowIfNull(tcs, nameof(tcs));
+
             ((TaskCompletionSource<object>)tcs).TrySetException(new TimeoutException("Transient RequestResponse timed out at (ms) " + defaultTimeoutMs));
         }
     }

Tapeti.UnityContainer/Tapeti.UnityContainer.csproj

@@ -1,34 +0,0 @@
-<Project Sdk="Microsoft.NET.Sdk">
-
-  <PropertyGroup>
-    <TargetFramework>netstandard2.0</TargetFramework>
-    <GenerateDocumentationFile>true</GenerateDocumentationFile>
-    <Authors>Mark van Renswoude</Authors>
-    <Company />
-    <Description>Unity container integration package for Tapeti</Description>
-    <PackageTags>rabbitmq tapeti unity</PackageTags>
-    <PackageLicenseExpression>Unlicense</PackageLicenseExpression>
-    <PackageProjectUrl>https://github.com/MvRens/Tapeti</PackageProjectUrl>
-    <PackageIcon>Tapeti.SimpleInjector.png</PackageIcon>
-    <Version>2.0.0</Version>
-  </PropertyGroup>
-
-  <ItemGroup>
-    <PackageReference Include="Unity" Version="5.11.10" />
-  </ItemGroup>
-
-  <ItemGroup>
-    <ProjectReference Include="..\Tapeti\Tapeti.csproj" />
-  </ItemGroup>
-
-  <ItemGroup>
-    <None Include="..\resources\icons\Tapeti.SimpleInjector.png">
-      <Pack>True</Pack>
-      <PackagePath></PackagePath>
-    </None>
-  </ItemGroup>
-
-  <ItemGroup>
-    <PackageReference Include="Microsoft.SourceLink.GitHub" Version="1.0.0" PrivateAssets="All"/>
-  </ItemGroup>
-</Project>

Tapeti.UnityContainer/UnityDependencyResolver.cs

@@ -1,90 +0,0 @@
-using System;
-using Unity;
-using Unity.Lifetime;
-
-namespace Tapeti.UnityContainer
-{
-    /// <inheritdoc />
-    /// <summary>
-    /// Dependency resolver and container implementation for SimpleInjector.
-    /// </summary>
-    public class UnityDependencyResolver : IDependencyContainer
-    {
-        private readonly IUnityContainer container;
-
-
-        /// <summary>
-        /// </summary>
-        public UnityDependencyResolver(IUnityContainer container)
-        {
-            this.container = container;
-        }
-
-
-        /// <inheritdoc />
-        public T Resolve<T>() where T : class
-        {
-            return container.Resolve<T>();
-        }
-
-        /// <inheritdoc />
-        public object Resolve(Type type)
-        {
-            return container.Resolve(type);
-        }
-
-
-        /// <inheritdoc />
-        public void RegisterDefault<TService, TImplementation>() where TService : class where TImplementation : class, TService
-        {
-            if (container.IsRegistered(typeof(TService)))
-                return;
-
-            container.RegisterType<TService, TImplementation>();
-        }
-
-        /// <inheritdoc />
-        public void RegisterDefault<TService>(Func<TService> factory) where TService : class
-        {
-            if (container.IsRegistered(typeof(TService)))
-                return;
-
-            container.RegisterFactory<TService>(c => factory());
-        }
-
-
-        /// <inheritdoc />
-        public void RegisterDefaultSingleton<TService, TImplementation>() where TService : class where TImplementation : class, TService
-        {
-            if (container.IsRegistered(typeof(TService)))
-                return;
-
-            container.RegisterSingleton<TService, TImplementation>();
-        }
-
-        /// <inheritdoc />
-        public void RegisterDefaultSingleton<TService>(TService instance) where TService : class
-        {
-            if (container.IsRegistered(typeof(TService)))
-                return;
-
-            container.RegisterInstance(instance);
-        }
-
-        /// <inheritdoc />
-        public void RegisterDefaultSingleton<TService>(Func<TService> factory) where TService : class
-        {
-            if (container.IsRegistered(typeof(TService)))
-                return;
-
-            container.RegisterFactory<TService>(c => factory(), new SingletonLifetimeManager());
-        }
-
-
-        /// <inheritdoc />
-        public void RegisterController(Type type)
-        {
-            container.RegisterType(type);
-        }
-    }
-}

Tapeti.sln

@@ -1,7 +1,7 @@
 
 Microsoft Visual Studio Solution File, Format Version 12.00
-# Visual Studio Version 16
+# Visual Studio Version 17
-VisualStudioVersion = 16.0.31005.135
+VisualStudioVersion = 17.0.32112.339
 MinimumVisualStudioVersion = 10.0.40219.1
 Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Tapeti", "Tapeti\Tapeti.csproj", "{2952B141-C54D-4E6F-8108-CAD735B0279F}"
 EndProject
@@ -45,8 +45,6 @@ Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Tapeti.CastleWindsor", "Tap
 EndProject
 Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Tapeti.Autofac", "Tapeti.Autofac\Tapeti.Autofac.csproj", "{B3802005-C941-41B6-A9A5-20573A7C24AE}"
 EndProject
-Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Tapeti.UnityContainer", "Tapeti.UnityContainer\Tapeti.UnityContainer.csproj", "{BA8CA9A2-BAFF-42BB-8439-3DD9D1F6C32E}"
-EndProject
 Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Tapeti.Ninject", "Tapeti.Ninject\Tapeti.Ninject.csproj", "{29478B10-FC53-4E93-ADEF-A775D9408131}"
 EndProject
 Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "06-StatelessRequestResponse", "Examples\06-StatelessRequestResponse\06-StatelessRequestResponse.csproj", "{152227AA-3165-4550-8997-6EA80C84516E}"
@@ -55,6 +53,8 @@ Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "07-ParallelizationTest", "E
 EndProject
 Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "08-MessageHandlerLogging", "Examples\08-MessageHandlerLogging\08-MessageHandlerLogging.csproj", "{906605A6-2CAB-4B29-B0DD-B735BF265E39}"
 EndProject
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Tapeti.Benchmarks", "Tapeti.Benchmarks\Tapeti.Benchmarks.csproj", "{DBE56131-9207-4CEA-BA3E-031351677C48}"
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Any CPU = Debug|Any CPU
@@ -129,10 +129,6 @@ Global
 		{B3802005-C941-41B6-A9A5-20573A7C24AE}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{B3802005-C941-41B6-A9A5-20573A7C24AE}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{B3802005-C941-41B6-A9A5-20573A7C24AE}.Release|Any CPU.Build.0 = Release|Any CPU
-		{BA8CA9A2-BAFF-42BB-8439-3DD9D1F6C32E}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
-		{BA8CA9A2-BAFF-42BB-8439-3DD9D1F6C32E}.Debug|Any CPU.Build.0 = Debug|Any CPU
-		{BA8CA9A2-BAFF-42BB-8439-3DD9D1F6C32E}.Release|Any CPU.ActiveCfg = Release|Any CPU
-		{BA8CA9A2-BAFF-42BB-8439-3DD9D1F6C32E}.Release|Any CPU.Build.0 = Release|Any CPU
 		{29478B10-FC53-4E93-ADEF-A775D9408131}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
 		{29478B10-FC53-4E93-ADEF-A775D9408131}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{29478B10-FC53-4E93-ADEF-A775D9408131}.Release|Any CPU.ActiveCfg = Release|Any CPU
@@ -149,6 +145,10 @@ Global
 		{906605A6-2CAB-4B29-B0DD-B735BF265E39}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{906605A6-2CAB-4B29-B0DD-B735BF265E39}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{906605A6-2CAB-4B29-B0DD-B735BF265E39}.Release|Any CPU.Build.0 = Release|Any CPU
+		{DBE56131-9207-4CEA-BA3E-031351677C48}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{DBE56131-9207-4CEA-BA3E-031351677C48}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{DBE56131-9207-4CEA-BA3E-031351677C48}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{DBE56131-9207-4CEA-BA3E-031351677C48}.Release|Any CPU.Build.0 = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE
@@ -170,7 +170,6 @@ Global
 		{330D05CE-5321-4C7D-8017-2070B891289E} = {266B9B94-A4D2-41C2-860C-24A7C3B63B56}
 		{374AAE64-598B-4F67-8870-4A05168FF987} = {99380F97-AD1A-459F-8AB3-D404E1E6AD4F}
 		{B3802005-C941-41B6-A9A5-20573A7C24AE} = {99380F97-AD1A-459F-8AB3-D404E1E6AD4F}
-		{BA8CA9A2-BAFF-42BB-8439-3DD9D1F6C32E} = {99380F97-AD1A-459F-8AB3-D404E1E6AD4F}
 		{29478B10-FC53-4E93-ADEF-A775D9408131} = {99380F97-AD1A-459F-8AB3-D404E1E6AD4F}
 		{152227AA-3165-4550-8997-6EA80C84516E} = {266B9B94-A4D2-41C2-860C-24A7C3B63B56}
 		{E69E6BA5-68E7-4A4D-A38C-B2526AA66E96} = {266B9B94-A4D2-41C2-860C-24A7C3B63B56}

Tapeti.sln.DotSettings

@@ -4,7 +4,9 @@
 	<s:String x:Key="/Default/CodeStyle/Naming/CSharpNaming/Abbreviations/=ID/@EntryIndexedValue">ID</s:String>
 	<s:String x:Key="/Default/CodeStyle/Naming/CSharpNaming/Abbreviations/=JSON/@EntryIndexedValue">JSON</s:String>
 	<s:String x:Key="/Default/CodeStyle/Naming/CSharpNaming/Abbreviations/=KV/@EntryIndexedValue">KV</s:String>
+	<s:String x:Key="/Default/CodeStyle/Naming/CSharpNaming/Abbreviations/=MQ/@EntryIndexedValue">MQ</s:String>
 	<s:String x:Key="/Default/CodeStyle/Naming/CSharpNaming/Abbreviations/=SQL/@EntryIndexedValue">SQL</s:String>
+	<s:String x:Key="/Default/CodeStyle/Naming/CSharpNaming/Abbreviations/=UTF/@EntryIndexedValue">UTF</s:String>
 	<s:String x:Key="/Default/CodeStyle/Naming/CSharpNaming/PredefinedNamingRules/=PrivateInstanceFields/@EntryIndexedValue">&lt;Policy Inspect="True" Prefix="" Suffix="" Style="aaBb" /&gt;</s:String>
 	<s:Boolean x:Key="/Default/Environment/SettingsMigration/IsMigratorApplied/=JetBrains_002EReSharper_002EPsi_002ECSharp_002ECodeStyle_002ECSharpKeepExistingMigration/@EntryIndexedValue">True</s:Boolean>
 	<s:Boolean x:Key="/Default/Environment/SettingsMigration/IsMigratorApplied/=JetBrains_002EReSharper_002EPsi_002ECSharp_002ECodeStyle_002ECSharpPlaceEmbeddedOnSameLineMigration/@EntryIndexedValue">True</s:Boolean>

Tapeti/Config/ControllerMessageContextPayload.cs

@@ -1,15 +1,14 @@
 namespace Tapeti.Config
 {
-    /// <inheritdoc />
     /// <summary>
     /// Extends the message context with information about the controller.
     /// </summary>
     public class ControllerMessageContextPayload : IMessageContextPayload
     {
         /// <summary>
-        /// An instance of the controller referenced by the binding. Note: can be null during Cleanup.
+        /// An instance of the controller referenced by the binding. Note: can be null during Cleanup or when bound to static methods.
         /// </summary>
-        public object Controller { get; }
+        public object? Controller { get; }
 
 
         /// <remarks>
@@ -23,7 +22,7 @@
         /// </summary>
         /// <param name="controller">An instance of the controller referenced by the binding</param>
         /// <param name="binding">The binding which is currently processing the message</param>
-        public ControllerMessageContextPayload(object controller, IControllerMethodBinding binding)
+        public ControllerMessageContextPayload(object? controller, IControllerMethodBinding binding)
         {
             Controller = controller;
             Binding = binding;

Tapeti/Config/IBinding.cs

@@ -1,5 +1,6 @@
 using System;
 using System.Threading.Tasks;
+using Tapeti.Connection;
 
 namespace Tapeti.Config
 {
@@ -28,20 +29,20 @@ namespace Tapeti.Config
         /// <summary>
         /// The name of the queue the binding is consuming. May change after a reconnect for dynamic queues.
         /// </summary>
-        string QueueName { get; }
+        string? QueueName { get; }
 
 
         /// <summary>
         /// Determines the type of queue the binding registers
         /// </summary>
-        QueueType QueueType { get; }
+        QueueType? QueueType { get; }
 
 
         /// <summary>
         /// Called after a connection is established to set up the binding.
         /// </summary>
         /// <param name="target"></param>
-        Task Apply(IBindingTarget target);
+        ValueTask Apply(IBindingTarget target);
 
 
         /// <summary>
@@ -55,7 +56,7 @@ namespace Tapeti.Config
         /// Invokes the handler for the message as specified by the context.
         /// </summary>
         /// <param name="context"></param>
-        Task Invoke(IMessageContext context);
+        ValueTask Invoke(IMessageContext context);
 
 
         /// <summary>
@@ -64,7 +65,7 @@ namespace Tapeti.Config
         /// <param name="context"></param>
         /// <param name="consumeResult"></param>
         /// <returns></returns>
-        Task Cleanup(IMessageContext context, ConsumeResult consumeResult);
+        ValueTask Cleanup(IMessageContext context, ConsumeResult consumeResult);
     }
 
 
@@ -80,7 +81,8 @@ namespace Tapeti.Config
         /// </summary>
         /// <param name="messageClass">The message class to be bound to the queue</param>
         /// <param name="queueName">The name of the durable queue</param>
-        Task BindDurable(Type messageClass, string queueName);
+        /// <param name="arguments">Optional arguments</param>
+        ValueTask BindDurable(Type messageClass, string queueName, IRabbitMQArguments? arguments);
 
         /// <summary>
         /// Binds the messageClass to a dynamic auto-delete queue.
@@ -91,15 +93,17 @@ namespace Tapeti.Config
         /// </remarks>
         /// <param name="messageClass">The message class to be bound to the queue</param>
         /// <param name="queuePrefix">An optional prefix for the dynamic queue's name. If not provided, RabbitMQ's default logic will be used to create an amq.gen queue.</param>
+        /// <param name="arguments">Optional arguments</param>
         /// <returns>The generated name of the dynamic queue</returns>
-        Task<string> BindDynamic(Type messageClass, string queuePrefix = null);
+        ValueTask<string> BindDynamic(Type messageClass, string? queuePrefix, IRabbitMQArguments? arguments);
 
         /// <summary>
         /// Declares a durable queue but does not add a binding for a messageClass' routing key.
         /// Used for direct-to-queue messages.
         /// </summary>
         /// <param name="queueName">The name of the durable queue</param>
-        Task BindDurableDirect(string queueName);
+        /// <param name="arguments">Optional arguments</param>
+        ValueTask BindDurableDirect(string queueName, IRabbitMQArguments? arguments);
 
         /// <summary>
         /// Declares a dynamic queue but does not add a binding for a messageClass' routing key.
@@ -107,22 +111,24 @@ namespace Tapeti.Config
         /// </summary>
         /// <param name="messageClass">The message class which will be handled on the queue. It is not actually bound to the queue.</param>
         /// <param name="queuePrefix">An optional prefix for the dynamic queue's name. If not provided, RabbitMQ's default logic will be used to create an amq.gen queue.</param>
+        /// <param name="arguments">Optional arguments</param>
         /// <returns>The generated name of the dynamic queue</returns>
-        Task<string> BindDynamicDirect(Type messageClass = null, string queuePrefix = null);
+        ValueTask<string> BindDynamicDirect(Type messageClass, string? queuePrefix, IRabbitMQArguments? arguments);
 
         /// <summary>
         /// Declares a dynamic queue but does not add a binding for a messageClass' routing key.
         /// Used for direct-to-queue messages. Guarantees a unique queue.
         /// </summary>
         /// <param name="queuePrefix">An optional prefix for the dynamic queue's name. If not provided, RabbitMQ's default logic will be used to create an amq.gen queue.</param>
+        /// <param name="arguments">Optional arguments</param>
         /// <returns>The generated name of the dynamic queue</returns>
-        Task<string> BindDynamicDirect(string queuePrefix = null);
+        ValueTask<string> BindDynamicDirect(string? queuePrefix, IRabbitMQArguments? arguments);
 
         /// <summary>
         /// Marks the specified durable queue as having an obsolete binding. If after all bindings have subscribed, the queue only contains obsolete
         /// bindings and is empty, it will be removed.
         /// </summary>
         /// <param name="queueName">The name of the durable queue</param>
-        Task BindDurableObsolete(string queueName);
+        ValueTask BindDurableObsolete(string queueName);
     }
 }

Tapeti/Config/IControllerBindingContext.cs

@@ -11,7 +11,7 @@ namespace Tapeti.Config
     /// Injects a value for a controller method parameter.
     /// </summary>
     /// <param name="context"></param>
-    public delegate object ValueFactory(IMessageContext context);
+    public delegate object? ValueFactory(IMessageContext context);
 
 
     /// <summary>
@@ -19,7 +19,7 @@ namespace Tapeti.Config
     /// </summary>
     /// <param name="context"></param>
     /// <param name="value"></param>
-    public delegate Task ResultHandler(IMessageContext context, object value);
+    public delegate ValueTask ResultHandler(IMessageContext context, object? value);
 
 
     /// <summary>
@@ -48,7 +48,7 @@ namespace Tapeti.Config
         /// The message class for this method. Can be null if not yet set by the default MessageBinding or other middleware.
         /// If required, call next first to ensure it is available.
         /// </summary>
-        Type MessageClass { get; }
+        Type? MessageClass { get; }
 
         /// <summary>
         /// Determines if SetMessageClass has already been called.

Tapeti/Config/IControllerBindingMiddleware.cs

@@ -2,7 +2,6 @@
 
 namespace Tapeti.Config
 {
-    /// <inheritdoc />
     /// <summary>
     /// Called when a Controller method is registered.
     /// </summary>

Tapeti/Config/IControllerCleanupMiddleware.cs

@@ -14,6 +14,6 @@ namespace Tapeti.Config
         /// <param name="context"></param>
         /// <param name="consumeResult"></param>
         /// <param name="next">Always call to allow the next in the chain to clean up</param>
-        Task Cleanup(IMessageContext context, ConsumeResult consumeResult, Func<Task> next);
+        ValueTask Cleanup(IMessageContext context, ConsumeResult consumeResult, Func<ValueTask> next);
     }
 }

Tapeti/Config/IControllerFilterMiddleware.cs

@@ -3,7 +3,6 @@ using System.Threading.Tasks;
 
 namespace Tapeti.Config
 {
-    /// <inheritdoc />
     /// <summary>
     /// Denotes middleware that runs before the controller is instantiated.
     /// </summary>
@@ -15,6 +14,6 @@ namespace Tapeti.Config
         /// <param name="context"></param>
         /// <param name="next"></param>
         /// <returns></returns>
-        Task Filter(IMessageContext context, Func<Task> next);
+        ValueTask Filter(IMessageContext context, Func<ValueTask> next);
     }
 }