Changes per PR feedback

src/SignalR/clients/csharp/Http.Connections.Client/src/HttpConnectionFactory.cs

@@ -93,7 +93,6 @@ internal static HttpConnectionOptions ShallowCopyHttpConnectionOptions(HttpConne
                 AccessTokenProvider = options.AccessTokenProvider,
                 CloseTimeout = options.CloseTimeout,
                 DefaultTransferFormat = options.DefaultTransferFormat,
-                WebSocketConfiguration = options.WebSocketConfiguration,
             };
 
             if (!OperatingSystem.IsBrowser())
@@ -103,6 +102,7 @@ internal static HttpConnectionOptions ShallowCopyHttpConnectionOptions(HttpConne
                 newOptions.Credentials = options.Credentials;
                 newOptions.Proxy = options.Proxy;
                 newOptions.UseDefaultCredentials = options.UseDefaultCredentials;
+                newOptions.WebSocketConfiguration = options.WebSocketConfiguration;
             }
 
             return newOptions;

src/SignalR/clients/csharp/Http.Connections.Client/src/HttpConnectionOptions.cs

@@ -26,6 +26,7 @@ public class HttpConnectionOptions
         private ICredentials _credentials;
         private IWebProxy _proxy;
         private bool? _useDefaultCredentials;
+        private Action<ClientWebSocketOptions> _webSocketConfiguration;
 
         /// <summary>
         /// Initializes a new instance of the <see cref="HttpConnectionOptions"/> class.
@@ -192,7 +193,20 @@ public bool? UseDefaultCredentials
         /// This delegate is invoked after headers from <see cref="Headers"/> and the access token from <see cref="AccessTokenProvider"/>
         /// has been applied.
         /// </remarks>
-        public Action<ClientWebSocketOptions> WebSocketConfiguration { get; set; }
+        [UnsupportedOSPlatform("browser")]
+        public Action<ClientWebSocketOptions> WebSocketConfiguration
+        {
+            get
+            {
+                ThrowIfUnsupportedPlatform();
+                return _webSocketConfiguration;
+            }
+            set
+            {
+                ThrowIfUnsupportedPlatform();
+                _webSocketConfiguration = value;
+            }
+        }
 
         private static void ThrowIfUnsupportedPlatform()
         {

src/SignalR/clients/csharp/Http.Connections.Client/src/Internal/WebSocketsTransport.Log.cs

@@ -69,6 +69,12 @@ private static class Log
             private static readonly Action<ILogger, Exception> _startedTransport =
                 LoggerMessage.Define(LogLevel.Debug, new EventId(19, "StartedTransport"), "Started transport.");
 
+            private static readonly Action<ILogger, Exception> _headersNotSupported =
+                LoggerMessage.Define(LogLevel.Warning, new EventId(20, "HeadersNotSupported"),
+                    $"Configuring request headers using {nameof(HttpConnectionOptions)}.{nameof(HttpConnectionOptions.Headers)} is not supported when using websockets transport " +
+                    "on the browser platform.");
+
+
             public static void StartTransport(ILogger logger, TransferFormat transferFormat, Uri webSocketUrl)
             {
                 _startTransport(logger, transferFormat, webSocketUrl, null);
@@ -163,6 +169,11 @@ public static void StartedTransport(ILogger logger)
             {
                 _startedTransport(logger, null);
             }
+
+            public static void HeadersNotSupported(ILogger logger)
+            {
+                _headersNotSupported(logger, null);
+            }
         }
     }
 }

src/SignalR/clients/csharp/Http.Connections.Client/src/Internal/WebSocketsTransport.cs

@@ -51,16 +51,18 @@ public WebSocketsTransport(HttpConnectionOptions httpConnectionOptions, ILoggerF
 
             if (httpConnectionOptions != null)
             {
-                if (httpConnectionOptions.Headers != null)
+                if (httpConnectionOptions.Headers.Count > 0)
                 {
                     if (isBrowser)
                     {
-                        throw new PlatformNotSupportedException("Configuring request headers is not supported when using WebSocketsTransport in the browser platform.");
+                        Log.HeadersNotSupported(_logger);
                     }
-
-                    foreach (var header in httpConnectionOptions.Headers)
+                    else
                     {
-                        _webSocket.Options.SetRequestHeader(header.Key, header.Value);
+                        foreach (var header in httpConnectionOptions.Headers)
+                        {
+                            _webSocket.Options.SetRequestHeader(header.Key, header.Value);
+                        }
                     }
                 }
 
@@ -90,9 +92,9 @@ public WebSocketsTransport(HttpConnectionOptions httpConnectionOptions, ILoggerF
                     {
                         _webSocket.Options.UseDefaultCredentials = httpConnectionOptions.UseDefaultCredentials.Value;
                     }
-                }
 
-                httpConnectionOptions.WebSocketConfiguration?.Invoke(_webSocket.Options);
+                    httpConnectionOptions.WebSocketConfiguration?.Invoke(_webSocket.Options);
+                }
             }
 
             if (!isBrowser)
@@ -101,7 +103,7 @@ public WebSocketsTransport(HttpConnectionOptions httpConnectionOptions, ILoggerF
                 // See: https://github.com/aspnet/Security/blob/ff9f145a8e89c9756ea12ff10c6d47f2f7eb345f/src/Microsoft.AspNetCore.Authentication.Cookies/Events/CookieAuthenticationEvents.cs#L42
 #pragma warning disable CA1416 // Analyzer bug
                 _webSocket.Options.SetRequestHeader("X-Requested-With", "XMLHttpRequest");
-#pragma warning restore CA1416 // Validate platform compatibility
+#pragma warning restore CA1416 // Analyzer bug
             }
 
             _closeTimeout = httpConnectionOptions?.CloseTimeout ?? default;

src/SignalR/common/Protocols.MessagePack/src/Microsoft.AspNetCore.SignalR.Protocols.MessagePack.csproj

@@ -2,7 +2,7 @@
 
   <PropertyGroup>
     <Description>Implements the SignalR Hub Protocol over MsgPack.</Description>
-    <TargetFrameworks>$(DefaultNetFxTargetFramework);netstandard2.0</TargetFrameworks>
+    <TargetFrameworks>$(DefaultNetCoreTargetFramework);$(DefaultNetFxTargetFramework);netstandard2.0</TargetFrameworks>
     <RootNamespace>Microsoft.AspNetCore.SignalR</RootNamespace>
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
     <Nullable>enable</Nullable>

src/SignalR/common/Protocols.MessagePack/src/Protocol/MessagePackHubProtocolWorker.cs

@@ -21,7 +21,7 @@ internal abstract class MessagePackHubProtocolWorker
         private const int VoidResult = 2;
         private const int NonVoidResult = 3;
 
-        public bool TryParseMessage(ref ReadOnlySequence<byte> input, IInvocationBinder binder, out HubMessage message)
+        public bool TryParseMessage(ref ReadOnlySequence<byte> input, IInvocationBinder binder, out HubMessage? message)
         {
             if (!BinaryMessageParser.TryParseMessage(ref input, out var payload))
             {
@@ -34,7 +34,7 @@ public bool TryParseMessage(ref ReadOnlySequence<byte> input, IInvocationBinder
             return true;
         }
 
-        private HubMessage ParseMessage(ref MessagePackReader reader, IInvocationBinder binder)
+        private HubMessage? ParseMessage(ref MessagePackReader reader, IInvocationBinder binder)
         {
             var itemCount = reader.ReadArrayHeader();
 
@@ -76,7 +76,7 @@ private HubMessage CreateInvocationMessage(ref MessagePackReader reader, IInvoca
 
             var target = ReadString(ref reader, "target");
 
-            object[] arguments = null;
+            object[]? arguments;
             try
             {
                 var parameterTypes = binder.GetParameterTypes(target);
@@ -87,7 +87,7 @@ private HubMessage CreateInvocationMessage(ref MessagePackReader reader, IInvoca
                 return new InvocationBindingFailureMessage(invocationId, target, ExceptionDispatchInfo.Capture(ex));
             }
 
-            string[] streams = null;
+            string[]? streams = null;
             // Previous clients will send 5 items, so we check if they sent a stream array or not
             if (itemCount > 5)
             {
@@ -103,7 +103,7 @@ private HubMessage CreateStreamInvocationMessage(ref MessagePackReader reader, I
             var invocationId = ReadInvocationId(ref reader);
             var target = ReadString(ref reader, "target");
 
-            object[] arguments = null;
+            object[] arguments;
             try
             {
                 var parameterTypes = binder.GetParameterTypes(target);
@@ -114,7 +114,7 @@ private HubMessage CreateStreamInvocationMessage(ref MessagePackReader reader, I
                 return new InvocationBindingFailureMessage(invocationId, target, ExceptionDispatchInfo.Capture(ex));
             }
 
-            string[] streams = null;
+            string[]? streams = null;
             // Previous clients will send 5 items, so we check if they sent a stream array or not
             if (itemCount > 5)
             {
@@ -148,8 +148,8 @@ private CompletionMessage CreateCompletionMessage(ref MessagePackReader reader,
             var invocationId = ReadInvocationId(ref reader);
             var resultKind = ReadInt32(ref reader, "resultKind");
 
-            string error = null;
-            object result = null;
+            string? error = null;
+            object? result = null;
             var hasResult = false;
 
             switch (resultKind)
@@ -198,7 +198,7 @@ private CloseMessage CreateCloseMessage(ref MessagePackReader reader, int itemCo
             return new CloseMessage(error, allowReconnect);
         }
 
-        private Dictionary<string, string> ReadHeaders(ref MessagePackReader reader)
+        private Dictionary<string, string>? ReadHeaders(ref MessagePackReader reader)
         {
             var headerCount = ReadMapLength(ref reader, "headers");
             if (headerCount > 0)
@@ -219,10 +219,10 @@ private Dictionary<string, string> ReadHeaders(ref MessagePackReader reader)
             }
         }
 
-        private string[] ReadStreamIds(ref MessagePackReader reader)
+        private string[]? ReadStreamIds(ref MessagePackReader reader)
         {
             var streamIdCount = ReadArrayLength(ref reader, "streamIds");
-            List<string> streams = null;
+            List<string>? streams = null;
 
             if (streamIdCount > 0)
             {
@@ -264,7 +264,7 @@ private object[] BindArguments(ref MessagePackReader reader, IReadOnlyList<Type>
 
         protected abstract object DeserializeObject(ref MessagePackReader reader, Type type, string field);
 
-        private T ApplyHeaders<T>(IDictionary<string, string> source, T destination) where T : HubInvocationMessage
+        private T ApplyHeaders<T>(IDictionary<string, string>? source, T destination) where T : HubInvocationMessage
         {
             if (source != null && source.Count > 0)
             {
@@ -374,10 +374,18 @@ private void WriteInvocationMessage(InvocationMessage message, ref MessagePackWr
                 writer.Write(message.InvocationId);
             }
             writer.Write(message.Target);
-            writer.WriteArrayHeader(message.Arguments.Length);
-            foreach (var arg in message.Arguments)
+
+            if (message.Arguments is null)
             {
-                WriteArgument(arg, ref writer);
+                writer.WriteArrayHeader(0);
+            }
+            else
+            {
+                writer.WriteArrayHeader(message.Arguments.Length);
+                foreach (var arg in message.Arguments)
+                {
+                    WriteArgument(arg, ref writer);
+                }
             }
 
             WriteStreamIds(message.StreamIds, ref writer);
@@ -392,10 +400,17 @@ private void WriteStreamInvocationMessage(StreamInvocationMessage message, ref M
             writer.Write(message.InvocationId);
             writer.Write(message.Target);
 
-            writer.WriteArrayHeader(message.Arguments.Length);
-            foreach (var arg in message.Arguments)
+            if (message.Arguments is null)
             {
-                WriteArgument(arg, ref writer);
+                writer.WriteArrayHeader(0);
+            }
+            else
+            {
+                writer.WriteArrayHeader(message.Arguments.Length);
+                foreach (var arg in message.Arguments)
+                {
+                    WriteArgument(arg, ref writer);
+                }
             }
 
             WriteStreamIds(message.StreamIds, ref writer);
@@ -410,7 +425,7 @@ private void WriteStreamingItemMessage(StreamItemMessage message, ref MessagePac
             WriteArgument(message.Item, ref writer);
         }
 
-        private void WriteArgument(object argument, ref MessagePackWriter writer)
+        private void WriteArgument(object? argument, ref MessagePackWriter writer)
         {
             if (argument == null)
             {
@@ -424,7 +439,7 @@ private void WriteArgument(object argument, ref MessagePackWriter writer)
 
         protected abstract void Serialize(ref MessagePackWriter writer, Type type, object value);
 
-        private void WriteStreamIds(string[] streamIds, ref MessagePackWriter writer)
+        private void WriteStreamIds(string[]? streamIds, ref MessagePackWriter writer)
         {
             if (streamIds != null)
             {
@@ -493,7 +508,7 @@ private void WritePingMessage(PingMessage pingMessage, ref MessagePackWriter wri
             writer.Write(HubProtocolConstants.PingMessageType);
         }
 
-        private void PackHeaders(IDictionary<string, string> headers, ref MessagePackWriter writer)
+        private void PackHeaders(IDictionary<string, string>? headers, ref MessagePackWriter writer)
         {
             if (headers != null)
             {

src/SignalR/common/Protocols.NewtonsoftJson/src/Microsoft.AspNetCore.SignalR.Protocols.NewtonsoftJson.csproj

@@ -2,7 +2,7 @@
 
   <PropertyGroup>
     <Description>Implements the SignalR Hub Protocol using Newtonsoft.Json.</Description>
-    <TargetFrameworks>$(DefaultNetFxTargetFramework);netstandard2.0</TargetFrameworks>
+    <TargetFrameworks>$(DefaultNetCoreTargetFramework);$(DefaultNetFxTargetFramework);netstandard2.0</TargetFrameworks>
     <RootNamespace>Microsoft.AspNetCore.SignalR</RootNamespace>
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
     <Nullable>enable</Nullable>

src/SignalR/common/Shared/JsonUtils.cs

@@ -143,7 +143,7 @@ public static bool ReadAsBoolean(JsonTextReader reader, string propertyName)
             return Convert.ToInt32(reader.Value, CultureInfo.InvariantCulture);
         }
 
-        public static string ReadAsString(JsonTextReader reader, string propertyName)
+        public static string? ReadAsString(JsonTextReader reader, string propertyName)
         {
             reader.Read();
 

src/SignalR/common/SignalR.Common/src/Protocol/HubMethodInvocationMessage.cs

@@ -146,7 +146,7 @@ public StreamInvocationMessage(string invocationId, string target, object[] argu
         /// <param name="target">The target method name.</param>
         /// <param name="arguments">The target method arguments.</param>
         /// <param name="streamIds">The target methods stream IDs.</param>
-        public StreamInvocationMessage(string invocationId, string target, object[] arguments, string[] streamIds)
+        public StreamInvocationMessage(string invocationId, string target, object[] arguments, string[]? streamIds)
             : base(invocationId, target, arguments, streamIds)
         {
         }

src/SignalR/common/SignalR.Common/src/Protocol/InvocationBindingFailureMessage.cs

@@ -26,7 +26,7 @@ public class InvocationBindingFailureMessage : HubInvocationMessage
         /// <param name="invocationId">The invocation ID.</param>
         /// <param name="target">The target method name.</param>
         /// <param name="bindingFailure">The exception thrown during binding.</param>
-        public InvocationBindingFailureMessage(string invocationId, string target, ExceptionDispatchInfo bindingFailure) : base(invocationId)
+        public InvocationBindingFailureMessage(string? invocationId, string target, ExceptionDispatchInfo bindingFailure) : base(invocationId)
         {
             Target = target;
             BindingFailure = bindingFailure;