Add acceptance tests for microsoft#960

Author: AArnott

Directory.Packages.props

@@ -4,7 +4,7 @@
   <PropertyGroup>
     <ManagePackageVersionsCentrally>true</ManagePackageVersionsCentrally>
     <CentralPackageTransitivePinningEnabled>true</CentralPackageTransitivePinningEnabled>
-    <MessagePackVersion>2.5.108</MessagePackVersion>
+    <MessagePackVersion>2.5.172</MessagePackVersion>
     <MicroBuildVersion>2.0.162</MicroBuildVersion>
     <VisualStudioThreadingVersion>17.10.48</VisualStudioThreadingVersion>
   </PropertyGroup>
@@ -29,7 +29,7 @@
     <PackageVersion Include="System.IO.Pipelines" Version="8.0.0" />
     <PackageVersion Include="System.IO.Pipes" Version="4.3.0" />
     <PackageVersion Include="System.Net.Http" Version="4.3.4" />
-    <PackageVersion Include="System.Text.Json" Version="8.0.3" />
+    <PackageVersion Include="System.Text.Json" Version="8.0.4" />
     <PackageVersion Include="System.Threading.Tasks.Dataflow" Version="6.0.0" />
     <PackageVersion Include="System.ValueTuple" Version="4.5.0" />
     <PackageVersion Include="xunit.combinatorial" Version="1.6.24" />

test/StreamJsonRpc.Tests/JsonRpcMessagePackLengthTests.cs

@@ -27,6 +27,8 @@ internal interface IMessagePackServer
         IAsyncEnumerable<UnionBaseClass> GetAsyncEnumerableOfUnionType(CancellationToken cancellationToken);
 
         Task<bool> IsExtensionArgNonNull(CustomExtensionType extensionValue);
+
+        Task<string?> GetAPropertyFromStruct([MessagePackFormatter(typeof(ProprietaryStructFormatter))] ProprietaryStruct value, CancellationToken cancellationToken);
     }
 
     protected override Type FormatterExceptionType => typeof(MessagePackSerializationException);
@@ -384,6 +386,23 @@ public async Task VerboseLoggingDoesNotFailWhenArgsDoNotDeserializePrimitively(b
         Assert.True(await clientProxy.IsExtensionArgNonNull(new CustomExtensionType()));
     }
 
+    [Fact]
+    public async Task FormatterOnParameter_Interface()
+    {
+        IMessagePackServer clientProxy = this.clientRpc.Attach<IMessagePackServer>();
+        const string expected = "Beehive";
+        string? actual = await clientProxy.GetAPropertyFromStruct(new ProprietaryStruct { A = expected }, this.TimeoutToken);
+        Assert.Equal(expected, actual);
+    }
+
+    [Fact]
+    public async Task FormatterOnParameter_NoInterface()
+    {
+        const string expected = "Beehive";
+        string? actual = await this.clientRpc.InvokeWithCancellationAsync<string?>(nameof(MessagePackServer.GetAPropertyFromStructNoInterface), [expected], this.TimeoutToken);
+        Assert.Equal(expected, actual);
+    }
+
     protected override void InitializeFormattersAndHandlers(
         Stream serverStream,
         Stream clientStream,
@@ -409,6 +428,14 @@ protected override void InitializeFormattersAndHandlers(
             : new LengthHeaderMessageHandler(clientStream, clientStream, clientMessageFormatter);
     }
 
+    /// <summary>
+    /// A struct that intentionally uses no MessagePack attributes so that a custom formatter will have to be provided.
+    /// </summary>
+    internal struct ProprietaryStruct
+    {
+        public string? A { get; set; }
+    }
+
     [MessagePackObject]
     [Union(0, typeof(UnionDerivedClass))]
     public abstract class UnionBaseClass
@@ -512,6 +539,16 @@ public async IAsyncEnumerable<UnionBaseClass> GetAsyncEnumerableOfUnionType([Enu
         }
 
         public Task<bool> IsExtensionArgNonNull(CustomExtensionType extensionValue) => Task.FromResult(extensionValue is not null);
+
+        public Task<string?> GetAPropertyFromStruct(ProprietaryStruct value, CancellationToken cancellationToken)
+        {
+            return Task.FromResult(value.A);
+        }
+
+        public Task<string?> GetAPropertyFromStructNoInterface([MessagePackFormatter(typeof(ProprietaryStructFormatter))] ProprietaryStruct value, CancellationToken cancellationToken)
+        {
+            return Task.FromResult(value.A);
+        }
     }
 
     private class DelayedFlushingHandler : LengthHeaderMessageHandler, IControlledFlushHandler
@@ -532,4 +569,17 @@ protected override async ValueTask FlushAsync(CancellationToken cancellationToke
             await base.FlushAsync(cancellationToken);
         }
     }
+
+    private class ProprietaryStructFormatter : IMessagePackFormatter<ProprietaryStruct>
+    {
+        public ProprietaryStruct Deserialize(ref MessagePackReader reader, MessagePackSerializerOptions options)
+        {
+            return new ProprietaryStruct { A = reader.ReadString() };
+        }
+
+        public void Serialize(ref MessagePackWriter writer, ProprietaryStruct value, MessagePackSerializerOptions options)
+        {
+            writer.Write(value.A);
+        }
+    }
 }