Merging internal commits for release/8.0

NuGet.config

@@ -6,8 +6,10 @@
     <!--  Begin: Package sources from dotnet-extensions -->
     <!--  End: Package sources from dotnet-extensions -->
     <!--  Begin: Package sources from dotnet-efcore -->
+    <add key="darc-int-dotnet-efcore-ccddb58" value="https://pkgs.dev.azure.com/dnceng/internal/_packaging/darc-int-dotnet-efcore-ccddb582/nuget/v3/index.json" />
     <!--  End: Package sources from dotnet-efcore -->
     <!--  Begin: Package sources from dotnet-runtime -->
+    <add key="darc-int-dotnet-runtime-b753199" value="https://pkgs.dev.azure.com/dnceng/internal/_packaging/darc-int-dotnet-runtime-b7531990/nuget/v3/index.json" />
     <!--  End: Package sources from dotnet-runtime -->
     <!--End: Package sources managed by Dependency Flow automation. Do not edit the sources above.-->
     <add key="dotnet-eng" value="https://pkgs.dev.azure.com/dnceng/public/_packaging/dotnet-eng/nuget/v3/index.json" />
@@ -28,8 +30,10 @@
     <clear />
     <!--Begin: Package sources managed by Dependency Flow automation. Do not edit the sources below.-->
     <!--  Begin: Package sources from dotnet-efcore -->
+    <add key="darc-int-dotnet-efcore-ccddb58" value="true" />
     <!--  End: Package sources from dotnet-efcore -->
     <!--  Begin: Package sources from dotnet-runtime -->
+    <add key="darc-int-dotnet-runtime-b753199" value="true" />
     <!--  End: Package sources from dotnet-runtime -->
     <!--End: Package sources managed by Dependency Flow automation. Do not edit the sources above.-->
   </disabledPackageSources>

eng/Version.Details.xml

@@ -9,37 +9,37 @@
 -->
 <Dependencies>
   <ProductDependencies>
-    <Dependency Name="dotnet-ef" Version="8.0.24">
+    <Dependency Name="dotnet-ef" Version="8.0.25">
       <Uri>https://dev.azure.com/dnceng/internal/_git/dotnet-efcore</Uri>
-      <Sha>5d939b1e793ba21104a8479b51b9d8c91f5777db</Sha>
+      <Sha>ccddb58237acbffdddb7678aad16dd1bf450cac8</Sha>
     </Dependency>
-    <Dependency Name="Microsoft.EntityFrameworkCore.InMemory" Version="8.0.24">
+    <Dependency Name="Microsoft.EntityFrameworkCore.InMemory" Version="8.0.25">
       <Uri>https://dev.azure.com/dnceng/internal/_git/dotnet-efcore</Uri>
-      <Sha>5d939b1e793ba21104a8479b51b9d8c91f5777db</Sha>
+      <Sha>ccddb58237acbffdddb7678aad16dd1bf450cac8</Sha>
     </Dependency>
-    <Dependency Name="Microsoft.EntityFrameworkCore.Relational" Version="8.0.24">
+    <Dependency Name="Microsoft.EntityFrameworkCore.Relational" Version="8.0.25">
       <Uri>https://dev.azure.com/dnceng/internal/_git/dotnet-efcore</Uri>
-      <Sha>5d939b1e793ba21104a8479b51b9d8c91f5777db</Sha>
+      <Sha>ccddb58237acbffdddb7678aad16dd1bf450cac8</Sha>
     </Dependency>
-    <Dependency Name="Microsoft.EntityFrameworkCore.Sqlite" Version="8.0.24">
+    <Dependency Name="Microsoft.EntityFrameworkCore.Sqlite" Version="8.0.25">
       <Uri>https://dev.azure.com/dnceng/internal/_git/dotnet-efcore</Uri>
-      <Sha>5d939b1e793ba21104a8479b51b9d8c91f5777db</Sha>
+      <Sha>ccddb58237acbffdddb7678aad16dd1bf450cac8</Sha>
     </Dependency>
-    <Dependency Name="Microsoft.EntityFrameworkCore.SqlServer" Version="8.0.24">
+    <Dependency Name="Microsoft.EntityFrameworkCore.SqlServer" Version="8.0.25">
       <Uri>https://dev.azure.com/dnceng/internal/_git/dotnet-efcore</Uri>
-      <Sha>5d939b1e793ba21104a8479b51b9d8c91f5777db</Sha>
+      <Sha>ccddb58237acbffdddb7678aad16dd1bf450cac8</Sha>
     </Dependency>
-    <Dependency Name="Microsoft.EntityFrameworkCore.Tools" Version="8.0.24">
+    <Dependency Name="Microsoft.EntityFrameworkCore.Tools" Version="8.0.25">
       <Uri>https://dev.azure.com/dnceng/internal/_git/dotnet-efcore</Uri>
-      <Sha>5d939b1e793ba21104a8479b51b9d8c91f5777db</Sha>
+      <Sha>ccddb58237acbffdddb7678aad16dd1bf450cac8</Sha>
     </Dependency>
-    <Dependency Name="Microsoft.EntityFrameworkCore" Version="8.0.24">
+    <Dependency Name="Microsoft.EntityFrameworkCore" Version="8.0.25">
       <Uri>https://dev.azure.com/dnceng/internal/_git/dotnet-efcore</Uri>
-      <Sha>5d939b1e793ba21104a8479b51b9d8c91f5777db</Sha>
+      <Sha>ccddb58237acbffdddb7678aad16dd1bf450cac8</Sha>
     </Dependency>
-    <Dependency Name="Microsoft.EntityFrameworkCore.Design" Version="8.0.24">
+    <Dependency Name="Microsoft.EntityFrameworkCore.Design" Version="8.0.25">
       <Uri>https://dev.azure.com/dnceng/internal/_git/dotnet-efcore</Uri>
-      <Sha>5d939b1e793ba21104a8479b51b9d8c91f5777db</Sha>
+      <Sha>ccddb58237acbffdddb7678aad16dd1bf450cac8</Sha>
     </Dependency>
     <Dependency Name="Microsoft.Extensions.Caching.Abstractions" Version="8.0.0">
       <Uri>https://dev.azure.com/dnceng/internal/_git/dotnet-runtime</Uri>
@@ -121,9 +121,9 @@
       <Uri>https://dev.azure.com/dnceng/internal/_git/dotnet-runtime</Uri>
       <Sha>5535e31a712343a63f5d7d796cd874e563e5ac14</Sha>
     </Dependency>
-    <Dependency Name="Microsoft.Extensions.HostFactoryResolver.Sources" Version="8.0.24-servicing.26070.10">
+    <Dependency Name="Microsoft.Extensions.HostFactoryResolver.Sources" Version="8.0.25-servicing.26112.3">
       <Uri>https://dev.azure.com/dnceng/internal/_git/dotnet-runtime</Uri>
-      <Sha>b3b35ce80e9eb94f72c4aa36a171a5e1cde72ace</Sha>
+      <Sha>b753199016332cbf257e70c417aa5d1d02202dc7</Sha>
     </Dependency>
     <Dependency Name="Microsoft.Extensions.Hosting.Abstractions" Version="8.0.1">
       <Uri>https://dev.azure.com/dnceng/internal/_git/dotnet-runtime</Uri>
@@ -185,9 +185,9 @@
       <Uri>https://dev.azure.com/dnceng/internal/_git/dotnet-runtime</Uri>
       <Sha>5535e31a712343a63f5d7d796cd874e563e5ac14</Sha>
     </Dependency>
-    <Dependency Name="Microsoft.Internal.Runtime.AspNetCore.Transport" Version="8.0.24-servicing.26070.10">
+    <Dependency Name="Microsoft.Internal.Runtime.AspNetCore.Transport" Version="8.0.25-servicing.26112.3">
       <Uri>https://dev.azure.com/dnceng/internal/_git/dotnet-runtime</Uri>
-      <Sha>b3b35ce80e9eb94f72c4aa36a171a5e1cde72ace</Sha>
+      <Sha>b753199016332cbf257e70c417aa5d1d02202dc7</Sha>
     </Dependency>
     <Dependency Name="Microsoft.SourceBuild.Intermediate.source-build-externals" Version="8.0.0-alpha.1.26152.1">
       <Uri>https://github.com/dotnet/source-build-externals</Uri>
@@ -275,17 +275,17 @@
       <Uri>https://dev.azure.com/dnceng/internal/_git/dotnet-runtime</Uri>
       <Sha>81cabf2857a01351e5ab578947c7403a5b128ad1</Sha>
     </Dependency>
-    <Dependency Name="Microsoft.NETCore.App.Ref" Version="8.0.24">
+    <Dependency Name="Microsoft.NETCore.App.Ref" Version="8.0.25">
       <Uri>https://dev.azure.com/dnceng/internal/_git/dotnet-runtime</Uri>
-      <Sha>b3b35ce80e9eb94f72c4aa36a171a5e1cde72ace</Sha>
+      <Sha>b753199016332cbf257e70c417aa5d1d02202dc7</Sha>
     </Dependency>
-    <Dependency Name="Microsoft.NET.Runtime.MonoAOTCompiler.Task" Version="8.0.24">
+    <Dependency Name="Microsoft.NET.Runtime.MonoAOTCompiler.Task" Version="8.0.25">
       <Uri>https://dev.azure.com/dnceng/internal/_git/dotnet-runtime</Uri>
-      <Sha>b3b35ce80e9eb94f72c4aa36a171a5e1cde72ace</Sha>
+      <Sha>b753199016332cbf257e70c417aa5d1d02202dc7</Sha>
     </Dependency>
-    <Dependency Name="Microsoft.NET.Runtime.WebAssembly.Sdk" Version="8.0.24">
+    <Dependency Name="Microsoft.NET.Runtime.WebAssembly.Sdk" Version="8.0.25">
       <Uri>https://dev.azure.com/dnceng/internal/_git/dotnet-runtime</Uri>
-      <Sha>b3b35ce80e9eb94f72c4aa36a171a5e1cde72ace</Sha>
+      <Sha>b753199016332cbf257e70c417aa5d1d02202dc7</Sha>
     </Dependency>
     <Dependency Name="Microsoft.Bcl.AsyncInterfaces" Version="8.0.0">
       <Uri>https://dev.azure.com/dnceng/internal/_git/dotnet-runtime</Uri>
@@ -316,22 +316,22 @@
          Win-x64 is used here because we have picked an arbitrary runtime identifier to flow the version of the latest NETCore.App runtime.
          All Runtime.$rid packages should have the same version.
     -->
-    <Dependency Name="Microsoft.NETCore.App.Runtime.win-x64" Version="8.0.24">
+    <Dependency Name="Microsoft.NETCore.App.Runtime.win-x64" Version="8.0.25">
       <Uri>https://dev.azure.com/dnceng/internal/_git/dotnet-runtime</Uri>
-      <Sha>b3b35ce80e9eb94f72c4aa36a171a5e1cde72ace</Sha>
+      <Sha>b753199016332cbf257e70c417aa5d1d02202dc7</Sha>
     </Dependency>
-    <Dependency Name="Microsoft.SourceBuild.Intermediate.runtime.linux-x64" Version="8.0.24-servicing.26070.10">
+    <Dependency Name="Microsoft.SourceBuild.Intermediate.runtime.linux-x64" Version="8.0.25-servicing.26112.3">
       <Uri>https://dev.azure.com/dnceng/internal/_git/dotnet-runtime</Uri>
-      <Sha>b3b35ce80e9eb94f72c4aa36a171a5e1cde72ace</Sha>
+      <Sha>b753199016332cbf257e70c417aa5d1d02202dc7</Sha>
       <SourceBuild RepoName="runtime" ManagedOnly="false" />
     </Dependency>
-    <Dependency Name="Microsoft.NETCore.App.Runtime.AOT.win-x64.Cross.browser-wasm" Version="8.0.24">
+    <Dependency Name="Microsoft.NETCore.App.Runtime.AOT.win-x64.Cross.browser-wasm" Version="8.0.25">
       <Uri>https://dev.azure.com/dnceng/internal/_git/dotnet-runtime</Uri>
-      <Sha>b3b35ce80e9eb94f72c4aa36a171a5e1cde72ace</Sha>
+      <Sha>b753199016332cbf257e70c417aa5d1d02202dc7</Sha>
     </Dependency>
-    <Dependency Name="Microsoft.NETCore.BrowserDebugHost.Transport" Version="8.0.24-servicing.26070.10">
+    <Dependency Name="Microsoft.NETCore.BrowserDebugHost.Transport" Version="8.0.25-servicing.26112.3">
       <Uri>https://dev.azure.com/dnceng/internal/_git/dotnet-runtime</Uri>
-      <Sha>b3b35ce80e9eb94f72c4aa36a171a5e1cde72ace</Sha>
+      <Sha>b753199016332cbf257e70c417aa5d1d02202dc7</Sha>
     </Dependency>
     <Dependency Name="Microsoft.Web.Xdt" Version="7.0.0-preview.22423.2">
       <Uri>https://github.com/dotnet/xdt</Uri>
@@ -368,9 +368,9 @@
   </ProductDependencies>
   <ToolsetDependencies>
     <!-- Listed explicitly to workaround https://github.com/dotnet/cli/issues/10528 -->
-    <Dependency Name="Microsoft.NETCore.Platforms" Version="8.0.24-servicing.26070.10">
+    <Dependency Name="Microsoft.NETCore.Platforms" Version="8.0.25-servicing.26112.3">
       <Uri>https://dev.azure.com/dnceng/internal/_git/dotnet-runtime</Uri>
-      <Sha>b3b35ce80e9eb94f72c4aa36a171a5e1cde72ace</Sha>
+      <Sha>b753199016332cbf257e70c417aa5d1d02202dc7</Sha>
     </Dependency>
     <Dependency Name="System.Drawing.Common" Version="8.0.0-rtm.23520.14">
       <Uri>https://github.com/dotnet/winforms</Uri>

eng/Versions.props

@@ -66,12 +66,12 @@
   <PropertyGroup Label="Automated">
     <!-- Packages from dotnet/runtime -->
     <MicrosoftExtensionsDependencyModelVersion>8.0.2</MicrosoftExtensionsDependencyModelVersion>
-    <MicrosoftNETCoreAppRefVersion>8.0.24</MicrosoftNETCoreAppRefVersion>
-    <MicrosoftNETCoreAppRuntimewinx64Version>8.0.24</MicrosoftNETCoreAppRuntimewinx64Version>
-    <MicrosoftNETRuntimeMonoAOTCompilerTaskVersion>8.0.24</MicrosoftNETRuntimeMonoAOTCompilerTaskVersion>
-    <MicrosoftNETRuntimeWebAssemblySdkVersion>8.0.24</MicrosoftNETRuntimeWebAssemblySdkVersion>
-    <MicrosoftNETCoreAppRuntimeAOTwinx64CrossbrowserwasmVersion>8.0.24</MicrosoftNETCoreAppRuntimeAOTwinx64CrossbrowserwasmVersion>
-    <MicrosoftNETCoreBrowserDebugHostTransportVersion>8.0.24-servicing.26070.10</MicrosoftNETCoreBrowserDebugHostTransportVersion>
+    <MicrosoftNETCoreAppRefVersion>8.0.25</MicrosoftNETCoreAppRefVersion>
+    <MicrosoftNETCoreAppRuntimewinx64Version>8.0.25</MicrosoftNETCoreAppRuntimewinx64Version>
+    <MicrosoftNETRuntimeMonoAOTCompilerTaskVersion>8.0.25</MicrosoftNETRuntimeMonoAOTCompilerTaskVersion>
+    <MicrosoftNETRuntimeWebAssemblySdkVersion>8.0.25</MicrosoftNETRuntimeWebAssemblySdkVersion>
+    <MicrosoftNETCoreAppRuntimeAOTwinx64CrossbrowserwasmVersion>8.0.25</MicrosoftNETCoreAppRuntimeAOTwinx64CrossbrowserwasmVersion>
+    <MicrosoftNETCoreBrowserDebugHostTransportVersion>8.0.25-servicing.26112.3</MicrosoftNETCoreBrowserDebugHostTransportVersion>
     <MicrosoftExtensionsCachingAbstractionsVersion>8.0.0</MicrosoftExtensionsCachingAbstractionsVersion>
     <MicrosoftExtensionsCachingMemoryVersion>8.0.1</MicrosoftExtensionsCachingMemoryVersion>
     <MicrosoftExtensionsConfigurationAbstractionsVersion>8.0.0</MicrosoftExtensionsConfigurationAbstractionsVersion>
@@ -92,7 +92,7 @@
     <MicrosoftExtensionsFileProvidersCompositeVersion>8.0.0</MicrosoftExtensionsFileProvidersCompositeVersion>
     <MicrosoftExtensionsFileProvidersPhysicalVersion>8.0.0</MicrosoftExtensionsFileProvidersPhysicalVersion>
     <MicrosoftExtensionsFileSystemGlobbingVersion>8.0.0</MicrosoftExtensionsFileSystemGlobbingVersion>
-    <MicrosoftExtensionsHostFactoryResolverSourcesVersion>8.0.24-servicing.26070.10</MicrosoftExtensionsHostFactoryResolverSourcesVersion>
+    <MicrosoftExtensionsHostFactoryResolverSourcesVersion>8.0.25-servicing.26112.3</MicrosoftExtensionsHostFactoryResolverSourcesVersion>
     <MicrosoftExtensionsHostingAbstractionsVersion>8.0.1</MicrosoftExtensionsHostingAbstractionsVersion>
     <MicrosoftExtensionsHostingVersion>8.0.1</MicrosoftExtensionsHostingVersion>
     <MicrosoftExtensionsHttpVersion>8.0.1</MicrosoftExtensionsHttpVersion>
@@ -108,7 +108,7 @@
     <MicrosoftExtensionsOptionsDataAnnotationsVersion>8.0.0</MicrosoftExtensionsOptionsDataAnnotationsVersion>
     <MicrosoftExtensionsOptionsVersion>8.0.2</MicrosoftExtensionsOptionsVersion>
     <MicrosoftExtensionsPrimitivesVersion>8.0.0</MicrosoftExtensionsPrimitivesVersion>
-    <MicrosoftInternalRuntimeAspNetCoreTransportVersion>8.0.24-servicing.26070.10</MicrosoftInternalRuntimeAspNetCoreTransportVersion>
+    <MicrosoftInternalRuntimeAspNetCoreTransportVersion>8.0.25-servicing.26112.3</MicrosoftInternalRuntimeAspNetCoreTransportVersion>
     <SystemConfigurationConfigurationManagerVersion>8.0.1</SystemConfigurationConfigurationManagerVersion>
     <SystemDiagnosticsDiagnosticSourceVersion>8.0.1</SystemDiagnosticsDiagnosticSourceVersion>
     <SystemDiagnosticsEventLogVersion>8.0.2</SystemDiagnosticsEventLogVersion>
@@ -128,9 +128,9 @@
     <SystemThreadingAccessControlVersion>8.0.0</SystemThreadingAccessControlVersion>
     <SystemThreadingChannelsVersion>8.0.0</SystemThreadingChannelsVersion>
     <SystemThreadingRateLimitingVersion>8.0.0</SystemThreadingRateLimitingVersion>
-    <MicrosoftSourceBuildIntermediateruntimelinuxx64Version>8.0.24-servicing.26070.10</MicrosoftSourceBuildIntermediateruntimelinuxx64Version>
+    <MicrosoftSourceBuildIntermediateruntimelinuxx64Version>8.0.25-servicing.26112.3</MicrosoftSourceBuildIntermediateruntimelinuxx64Version>
     <!-- Only listed explicitly to workaround https://github.com/dotnet/cli/issues/10528 -->
-    <MicrosoftNETCorePlatformsVersion>8.0.24-servicing.26070.10</MicrosoftNETCorePlatformsVersion>
+    <MicrosoftNETCorePlatformsVersion>8.0.25-servicing.26112.3</MicrosoftNETCorePlatformsVersion>
     <MicrosoftBclAsyncInterfacesVersion>8.0.0</MicrosoftBclAsyncInterfacesVersion>
     <!-- Transitive package to provide coherency in dotnet/extensions -->
     <MicrosoftBclTimeProviderVersion>8.0.1</MicrosoftBclTimeProviderVersion>
@@ -142,14 +142,14 @@
     <MicrosoftExtensionsDiagnosticsTestingVersion>9.0.0-preview.9.24518.1</MicrosoftExtensionsDiagnosticsTestingVersion>
     <MicrosoftExtensionsTimeProviderTestingVersion>9.0.0-preview.9.24518.1</MicrosoftExtensionsTimeProviderTestingVersion>
     <!-- Packages from dotnet/efcore -->
-    <dotnetefVersion>8.0.24</dotnetefVersion>
-    <MicrosoftEntityFrameworkCoreInMemoryVersion>8.0.24</MicrosoftEntityFrameworkCoreInMemoryVersion>
-    <MicrosoftEntityFrameworkCoreRelationalVersion>8.0.24</MicrosoftEntityFrameworkCoreRelationalVersion>
-    <MicrosoftEntityFrameworkCoreSqliteVersion>8.0.24</MicrosoftEntityFrameworkCoreSqliteVersion>
-    <MicrosoftEntityFrameworkCoreSqlServerVersion>8.0.24</MicrosoftEntityFrameworkCoreSqlServerVersion>
-    <MicrosoftEntityFrameworkCoreToolsVersion>8.0.24</MicrosoftEntityFrameworkCoreToolsVersion>
-    <MicrosoftEntityFrameworkCoreVersion>8.0.24</MicrosoftEntityFrameworkCoreVersion>
-    <MicrosoftEntityFrameworkCoreDesignVersion>8.0.24</MicrosoftEntityFrameworkCoreDesignVersion>
+    <dotnetefVersion>8.0.25</dotnetefVersion>
+    <MicrosoftEntityFrameworkCoreInMemoryVersion>8.0.25</MicrosoftEntityFrameworkCoreInMemoryVersion>
+    <MicrosoftEntityFrameworkCoreRelationalVersion>8.0.25</MicrosoftEntityFrameworkCoreRelationalVersion>
+    <MicrosoftEntityFrameworkCoreSqliteVersion>8.0.25</MicrosoftEntityFrameworkCoreSqliteVersion>
+    <MicrosoftEntityFrameworkCoreSqlServerVersion>8.0.25</MicrosoftEntityFrameworkCoreSqlServerVersion>
+    <MicrosoftEntityFrameworkCoreToolsVersion>8.0.25</MicrosoftEntityFrameworkCoreToolsVersion>
+    <MicrosoftEntityFrameworkCoreVersion>8.0.25</MicrosoftEntityFrameworkCoreVersion>
+    <MicrosoftEntityFrameworkCoreDesignVersion>8.0.25</MicrosoftEntityFrameworkCoreDesignVersion>
     <!-- Packages from dotnet/roslyn -->
     <MicrosoftCodeAnalysisCommonVersion>4.8.0-7.24574.2</MicrosoftCodeAnalysisCommonVersion>
     <MicrosoftCodeAnalysisExternalAccessAspNetCoreVersion>4.8.0-7.24574.2</MicrosoftCodeAnalysisExternalAccessAspNetCoreVersion>

src/SignalR/clients/csharp/Client.Core/src/HubConnection.cs

@@ -2073,10 +2073,24 @@ public async Task TimerLoop(TimerAwaitable timer)
             }
         }
 
-        public ValueTask<FlushResult> WriteAsync(HubMessage message, CancellationToken cancellationToken)
+        public async ValueTask<FlushResult> WriteAsync(HubMessage message, CancellationToken cancellationToken)
         {
             Debug.Assert(_messageBuffer is not null);
-            return _messageBuffer.WriteAsync(message, cancellationToken);
+            CancellationTokenSource? cts = null;
+            var connectionToken = _hubConnection._state.StopCts.Token;
+            // StopAsync might have been called which would trigger the StopCts and thus prevent the CloseMessage from being sent.
+            // We'll use a short-lived token for CloseMessage specifically that isn't tied to the StopCts so we have a good chance of
+            // sending the CloseMessage to the server.
+            if (message is CloseMessage)
+            {
+                cts = new CancellationTokenSource(TimeSpan.FromSeconds(5));
+                connectionToken = cts.Token;
+            }
+
+            using var __ = cts;
+
+            using var _ = CancellationTokenUtils.CreateLinkedToken(cancellationToken, connectionToken, out var linkedToken);
+            return await _messageBuffer.WriteAsync(message, linkedToken).ConfigureAwait(false);
         }
 
         public bool ShouldProcessMessage(HubMessage message)

src/SignalR/clients/csharp/Client/test/UnitTests/HubConnectionTests.cs

@@ -941,6 +941,8 @@ public async Task DisableReconnectCalledWhenSendingCloseMessage()
         Assert.Null(exception);
 
         await reconnectFeature.DisableReconnectCalled.DefaultTimeout();
+
+        Assert.Equal("{\"type\":7}", await innerConnection.ReadSentTextMessageAsync().DefaultTimeout());
     }
 
     private class SampleObject

src/SignalR/common/Shared/MessageBuffer.cs

@@ -132,6 +132,9 @@ public ValueTask<FlushResult> WriteAsync(HubMessage hubMessage, CancellationToke
 
     private async ValueTask<FlushResult> WriteAsyncCore(Type hubMessageType, ReadOnlyMemory<byte> messageBytes, CancellationToken cancellationToken)
     {
+        // If backpressure is being observed a cancelable token is needed to make sure we can break out of waiting when the connection is closed
+        Debug.Assert(cancellationToken.CanBeCanceled);
+
         // TODO: Add backpressure based on message count
         if (_bufferedByteCount > _bufferLimit)
         {