MsgPack end-to-end

Plugging in MsgPack protocol
Adding negotiation message to hub protocol

src/Microsoft.AspNetCore.SignalR.Client/HubConnection.cs

@@ -4,6 +4,7 @@
 using System;
 using System.Collections.Concurrent;
 using System.Collections.Generic;
+using System.IO;
 using System.Linq;
 using System.Threading;
 using System.Threading.Tasks;
@@ -77,6 +78,12 @@ namespace Microsoft.AspNetCore.SignalR.Client
         public async Task StartAsync()
         {
             await _connection.StartAsync();
+
+            using (var memoryStream = new MemoryStream())
+            {
+                NegotiationProtocol.TryWriteProtocolNegotiationMessage(new NegotiationMessage(_protocol.Name), memoryStream);
+                await _connection.SendAsync(memoryStream.ToArray(), _connectionActive.Token);
+            }
         }
 
         public async Task DisposeAsync()

src/Microsoft.AspNetCore.SignalR.Common/Internal/Protocol/HubMessage.cs

@@ -1,8 +1,6 @@
 // Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
-using System;
-
 namespace Microsoft.AspNetCore.SignalR.Internal.Protocol
 {
     public abstract class HubMessage

src/Microsoft.AspNetCore.SignalR.Common/Internal/Protocol/IHubProtocol.cs

@@ -2,7 +2,6 @@
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
 using System;
-using System.Buffers;
 using System.Collections.Generic;
 using System.IO;
 
@@ -10,6 +9,8 @@ namespace Microsoft.AspNetCore.SignalR.Internal.Protocol
 {
     public interface IHubProtocol
     {
+        string Name { get; }
+
         bool TryParseMessages(ReadOnlySpan<byte> input, IInvocationBinder binder, out IList<HubMessage> messages);
 
         bool TryWriteMessage(HubMessage message, Stream output);

src/Microsoft.AspNetCore.SignalR.Common/Internal/Protocol/JsonHubProtocol.cs

@@ -44,6 +44,8 @@ namespace Microsoft.AspNetCore.SignalR.Internal.Protocol
             _payloadSerializer = payloadSerializer;
         }
 
+        public string Name { get => "json"; }
+
         public bool TryParseMessages(ReadOnlySpan<byte> input, IInvocationBinder binder, out IList<HubMessage> messages)
         {
             messages = new List<HubMessage>();
@@ -80,20 +82,16 @@ namespace Microsoft.AspNetCore.SignalR.Internal.Protocol
                 {
                     // PERF: Could probably use the JsonTextReader directly for better perf and fewer allocations
                     var token = JToken.ReadFrom(reader);
-                    if (token == null)
-                    {
-                        return null;
-                    }
 
-                    if (token.Type != JTokenType.Object)
+                    if (token == null || token.Type != JTokenType.Object)
                     {
-                        throw new FormatException($"Unexpected JSON Token Type '{token.Type}'. Expected a JSON Object.");
+                        throw new FormatException($"Unexpected JSON Token Type '{token?.Type}'. Expected a JSON Object.");
                     }
 
                     var json = (JObject)token;
 
                     // Determine the type of the message
-                    var type = GetRequiredProperty<int>(json, TypePropertyName, JTokenType.Integer);
+                    var type = JsonUtils.GetRequiredProperty<int>(json, TypePropertyName, JTokenType.Integer);
                     switch (type)
                     {
                         case InvocationMessageType:
@@ -194,11 +192,11 @@ namespace Microsoft.AspNetCore.SignalR.Internal.Protocol
 
         private InvocationMessage BindInvocationMessage(JObject json, IInvocationBinder binder)
         {
-            var invocationId = GetRequiredProperty<string>(json, InvocationIdPropertyName, JTokenType.String);
+            var invocationId = JsonUtils.GetRequiredProperty<string>(json, InvocationIdPropertyName, JTokenType.String);
-            var target = GetRequiredProperty<string>(json, TargetPropertyName, JTokenType.String);
+            var target = JsonUtils.GetRequiredProperty<string>(json, TargetPropertyName, JTokenType.String);
-            var nonBlocking = GetOptionalProperty<bool>(json, NonBlockingPropertyName, JTokenType.Boolean);
+            var nonBlocking = JsonUtils.GetOptionalProperty<bool>(json, NonBlockingPropertyName, JTokenType.Boolean);
 
-            var args = GetRequiredProperty<JArray>(json, ArgumentsPropertyName, JTokenType.Array);
+            var args = JsonUtils.GetRequiredProperty<JArray>(json, ArgumentsPropertyName, JTokenType.Array);
 
             var paramTypes = binder.GetParameterTypes(target);
             var arguments = new object[args.Count];
@@ -221,8 +219,8 @@ namespace Microsoft.AspNetCore.SignalR.Internal.Protocol
 
         private StreamItemMessage BindResultMessage(JObject json, IInvocationBinder binder)
         {
-            var invocationId = GetRequiredProperty<string>(json, InvocationIdPropertyName, JTokenType.String);
+            var invocationId = JsonUtils.GetRequiredProperty<string>(json, InvocationIdPropertyName, JTokenType.String);
-            var result = GetRequiredProperty<JToken>(json, ItemPropertyName);
+            var result = JsonUtils.GetRequiredProperty<JToken>(json, ItemPropertyName);
 
             var returnType = binder.GetReturnType(invocationId);
             return new StreamItemMessage(invocationId, result?.ToObject(returnType, _payloadSerializer));
@@ -230,8 +228,8 @@ namespace Microsoft.AspNetCore.SignalR.Internal.Protocol
 
         private CompletionMessage BindCompletionMessage(JObject json, IInvocationBinder binder)
         {
-            var invocationId = GetRequiredProperty<string>(json, InvocationIdPropertyName, JTokenType.String);
+            var invocationId = JsonUtils.GetRequiredProperty<string>(json, InvocationIdPropertyName, JTokenType.String);
-            var error = GetOptionalProperty<string>(json, ErrorPropertyName, JTokenType.String);
+            var error = JsonUtils.GetOptionalProperty<string>(json, ErrorPropertyName, JTokenType.String);
             var resultProp = json.Property(ResultPropertyName);
 
             if (error != null && resultProp != null)
@@ -250,38 +248,5 @@ namespace Microsoft.AspNetCore.SignalR.Internal.Protocol
                 return new CompletionMessage(invocationId, error, result: payload, hasResult: true);
             }
         }
-
-        private T GetOptionalProperty<T>(JObject json, string property, JTokenType expectedType = JTokenType.None, T defaultValue = default(T))
-        {
-            var prop = json[property];
-
-            if (prop == null)
-            {
-                return defaultValue;
-            }
-
-            return GetValue<T>(property, expectedType, prop);
-        }
-
-        private T GetRequiredProperty<T>(JObject json, string property, JTokenType expectedType = JTokenType.None)
-        {
-            var prop = json[property];
-
-            if (prop == null)
-            {
-                throw new FormatException($"Missing required property '{property}'.");
-            }
-
-            return GetValue<T>(property, expectedType, prop);
-        }
-
-        private static T GetValue<T>(string property, JTokenType expectedType, JToken prop)
-        {
-            if (expectedType != JTokenType.None && prop.Type != expectedType)
-            {
-                throw new FormatException($"Expected '{property}' to be of type {expectedType}.");
-            }
-            return prop.Value<T>();
-        }
     }
 }

src/Microsoft.AspNetCore.SignalR.Common/Internal/Protocol/JsonUtils.cs

@@ -0,0 +1,44 @@
+// Copyright (c) .NET Foundation. All rights reserved.
+// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
+
+using System;
+using Newtonsoft.Json.Linq;
+
+namespace Microsoft.AspNetCore.SignalR.Internal.Protocol
+{
+    public static class JsonUtils
+    {
+        public static T GetOptionalProperty<T>(JObject json, string property, JTokenType expectedType = JTokenType.None, T defaultValue = default(T))
+        {
+            var prop = json[property];
+
+            if (prop == null)
+            {
+                return defaultValue;
+            }
+
+            return GetValue<T>(property, expectedType, prop);
+        }
+
+        public static T GetRequiredProperty<T>(JObject json, string property, JTokenType expectedType = JTokenType.None)
+        {
+            var prop = json[property];
+
+            if (prop == null)
+            {
+                throw new FormatException($"Missing required property '{property}'.");
+            }
+
+            return GetValue<T>(property, expectedType, prop);
+        }
+
+        public static T GetValue<T>(string property, JTokenType expectedType, JToken prop)
+        {
+            if (expectedType != JTokenType.None && prop.Type != expectedType)
+            {
+                throw new FormatException($"Expected '{property}' to be of type {expectedType}.");
+            }
+            return prop.Value<T>();
+        }
+    }
+}

src/Microsoft.AspNetCore.SignalR.Common/Internal/Protocol/MessagePackHubProtocol.cs

@@ -16,6 +16,8 @@ namespace Microsoft.AspNetCore.SignalR.Internal.Protocol
         private const int StreamItemMessageType = 2;
         private const int CompletionMessageType = 3;
 
+        public string Name { get => "messagepack"; }
+
         public bool TryParseMessages(ReadOnlySpan<byte> input, IInvocationBinder binder, out IList<HubMessage> messages)
         {
             messages = new List<HubMessage>();

src/Microsoft.AspNetCore.SignalR.Common/Internal/Protocol/NegotiationMessage.cs

@@ -0,0 +1,15 @@
+// Copyright (c) .NET Foundation. All rights reserved.
+// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
+
+namespace Microsoft.AspNetCore.SignalR.Internal.Protocol
+{
+    public class NegotiationMessage
+    {
+        public NegotiationMessage(string protocol)
+        {
+            Protocol = protocol;
+        }
+
+        public string Protocol { get; }
+    }
+}

src/Microsoft.AspNetCore.SignalR.Common/Internal/Protocol/NegotiationProtocol.cs

@@ -0,0 +1,59 @@
+// Copyright (c) .NET Foundation. All rights reserved.
+// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
+
+using System;
+using System.IO;
+using Microsoft.AspNetCore.Sockets.Internal.Formatters;
+using Newtonsoft.Json;
+using Newtonsoft.Json.Linq;
+
+namespace Microsoft.AspNetCore.SignalR.Internal.Protocol
+{
+    public static class NegotiationProtocol
+    {
+        private const string ProtocolPropertyName = "protocol";
+
+        public static bool TryWriteProtocolNegotiationMessage(NegotiationMessage negotiationMessage, Stream output)
+        {
+            using (var memoryStream = new MemoryStream())
+            {
+                using (var writer = new JsonTextWriter(new StreamWriter(memoryStream)))
+                {
+                    writer.WriteStartObject();
+                    writer.WritePropertyName(ProtocolPropertyName);
+                    writer.WriteValue(negotiationMessage.Protocol);
+                    writer.WriteEndObject();
+                }
+
+                memoryStream.Flush();
+                return TextMessageFormatter.TryWriteMessage(new ReadOnlySpan<byte>(memoryStream.ToArray()), output);
+            }
+        }
+
+        public static bool TryReadProtocolNegotiationMessage(ReadOnlySpan<byte> input, out NegotiationMessage negotiationMessage)
+        {
+            var parser = new TextMessageParser();
+            if (!parser.TryParseMessage(ref input, out var payload))
+            {
+                throw new FormatException("Unable to parse payload as a negotiation message.");
+            }
+
+            using (var memoryStream = new MemoryStream(payload.ToArray()))
+            {
+                using (var reader = new JsonTextReader(new StreamReader(memoryStream)))
+                {
+                    var token = JToken.ReadFrom(reader);
+                    if (token == null || token.Type != JTokenType.Object)
+                    {
+                        throw new FormatException($"Unexpected JSON Token Type '{token?.Type}'. Expected a JSON Object.");
+                    }
+
+                    var negotiationJObject = (JObject)token;
+                    var protocol = JsonUtils.GetRequiredProperty<string>(negotiationJObject, ProtocolPropertyName);
+                    negotiationMessage = new NegotiationMessage(protocol);
+                }
+            }
+            return true;
+        }
+    }
+}

src/Microsoft.AspNetCore.SignalR/HubEndPoint.cs

@@ -59,13 +59,10 @@ namespace Microsoft.AspNetCore.SignalR
 
         public async Task OnConnectedAsync(ConnectionContext connection)
         {
+            await ProcessNegotiate(connection);
+
             try
             {
-                // Resolve the Hub Protocol for the connection and store it in metadata
-                // Other components, outside the Hub, may need to know what protocol is in use
-                // for a particular connection, so we store it here.
-                connection.Metadata[HubConnectionMetadataNames.HubProtocol] = _protocolResolver.GetProtocol(connection);
-
                 await _lifetimeManager.OnConnectedAsync(connection);
                 await RunHubAsync(connection);
             }
@@ -75,6 +72,26 @@ namespace Microsoft.AspNetCore.SignalR
             }
         }
 
+        private async Task ProcessNegotiate(ConnectionContext connection)
+        {
+            while (await connection.Transport.In.WaitToReadAsync())
+            {
+                while (connection.Transport.In.TryRead(out var buffer))
+                {
+                    if (NegotiationProtocol.TryReadProtocolNegotiationMessage(buffer, out var negotiationMessage))
+                    {
+                        // Resolve the Hub Protocol for the connection and store it in metadata
+                        // Other components, outside the Hub, may need to know what protocol is in use
+                        // for a particular connection, so we store it here.
+                        connection.Metadata[HubConnectionMetadataNames.HubProtocol] =
+                            _protocolResolver.GetProtocol(negotiationMessage.Protocol, connection);
+
+                        return;
+                    }
+                }
+            }
+        }
+
         private async Task RunHubAsync(ConnectionContext connection)
         {
             await HubOnConnectedAsync(connection);

src/Microsoft.AspNetCore.SignalR/Internal/DefaultHubProtocolResolver.cs

@@ -1,6 +1,7 @@
 // Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
+using System;
 using Microsoft.AspNetCore.SignalR.Internal.Protocol;
 using Microsoft.AspNetCore.Sockets;
 using Newtonsoft.Json;
@@ -9,10 +10,17 @@ namespace Microsoft.AspNetCore.SignalR.Internal
 {
     public class DefaultHubProtocolResolver : IHubProtocolResolver
     {
-        public IHubProtocol GetProtocol(ConnectionContext connection)
+        public IHubProtocol GetProtocol(string protocolName, ConnectionContext connection)
         {
-            // TODO: Allow customization of this serializer!
+            switch (protocolName?.ToLowerInvariant())
-            return new JsonHubProtocol(new JsonSerializer());
+            {
+                case "json":
+                    return new JsonHubProtocol(new JsonSerializer());
+                case "messagepack":
+                    return new MessagePackHubProtocol();
+                default:
+                    throw new NotSupportedException($"The protocol '{protocolName ?? "(null)"}' is not supported.");
+            }
         }
     }
 }

src/Microsoft.AspNetCore.SignalR/Internal/IHubProtocolResolver.cs

@@ -8,6 +8,6 @@ namespace Microsoft.AspNetCore.SignalR.Internal
 {
     public interface IHubProtocolResolver
     {
-        IHubProtocol GetProtocol(ConnectionContext connection);
+        IHubProtocol GetProtocol(string protocolName, ConnectionContext connection);
     }
 }

test/Microsoft.AspNetCore.SignalR.Client.FunctionalTests/HubConnectionTests.cs

@@ -2,11 +2,13 @@
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
 using System;
+using System.Collections.Generic;
 using System.Reactive.Linq;
 using System.Threading.Tasks;
 using System.Threading.Tasks.Channels;
 using Microsoft.AspNetCore.Builder;
 using Microsoft.AspNetCore.Hosting;
+using Microsoft.AspNetCore.SignalR.Internal.Protocol;
 using Microsoft.AspNetCore.SignalR.Tests.Common;
 using Microsoft.AspNetCore.Sockets;
 using Microsoft.AspNetCore.Sockets.Client;
@@ -14,6 +16,7 @@ using Microsoft.AspNetCore.TestHost;
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.Logging;
 using Microsoft.Extensions.Logging.Console;
+using Newtonsoft.Json;
 using Xunit;
 
 namespace Microsoft.AspNetCore.SignalR.Client.FunctionalTests
@@ -47,13 +50,14 @@ namespace Microsoft.AspNetCore.SignalR.Client.FunctionalTests
             _testServer = new TestServer(webHostBuilder);
         }
 
-        [Fact]
+        [Theory]
-        public async Task CheckFixedMessage()
+        [MemberData(nameof(HubProtocols))]
+        public async Task CheckFixedMessage(IHubProtocol protocol)
         {
             var loggerFactory = CreateLogger();
 
             var httpConnection = new HttpConnection(new Uri("http://test/hubs"), TransportType.LongPolling, loggerFactory, _testServer.CreateHandler());
-            var connection = new HubConnection(httpConnection, loggerFactory);
+            var connection = new HubConnection(httpConnection, protocol, loggerFactory);
             try
             {
                 await connection.StartAsync();
@@ -68,14 +72,15 @@ namespace Microsoft.AspNetCore.SignalR.Client.FunctionalTests
             }
         }
 
-        [Fact]
+        [Theory]
-        public async Task CanSendAndReceiveMessage()
+        [MemberData(nameof(HubProtocols))]
+        public async Task CanSendAndReceiveMessage(IHubProtocol protocol)
         {
             var loggerFactory = CreateLogger();
             const string originalMessage = "SignalR";
 
             var httpConnection = new HttpConnection(new Uri("http://test/hubs"), TransportType.LongPolling, loggerFactory, _testServer.CreateHandler());
-            var connection = new HubConnection(httpConnection, loggerFactory);
+            var connection = new HubConnection(httpConnection, protocol, loggerFactory);
             try
             {
                 await connection.StartAsync();
@@ -90,14 +95,15 @@ namespace Microsoft.AspNetCore.SignalR.Client.FunctionalTests
             }
         }
 
-        [Fact]
+        [Theory]
-        public async Task MethodsAreCaseInsensitive()
+        [MemberData(nameof(HubProtocols))]
+        public async Task MethodsAreCaseInsensitive(IHubProtocol protocol)
         {
             var loggerFactory = CreateLogger();
             const string originalMessage = "SignalR";
 
             var httpConnection = new HttpConnection(new Uri("http://test/hubs"), TransportType.LongPolling, loggerFactory, _testServer.CreateHandler());
-            var connection = new HubConnection(httpConnection, loggerFactory);
+            var connection = new HubConnection(httpConnection, protocol, loggerFactory);
             try
             {
                 await connection.StartAsync();
@@ -112,14 +118,15 @@ namespace Microsoft.AspNetCore.SignalR.Client.FunctionalTests
             }
         }
 
-        [Fact]
+        [Theory]
-        public async Task CanInvokeClientMethodFromServer()
+        [MemberData(nameof(HubProtocols))]
+        public async Task CanInvokeClientMethodFromServer(IHubProtocol protocol)
         {
             var loggerFactory = CreateLogger();
             const string originalMessage = "SignalR";
 
             var httpConnection = new HttpConnection(new Uri("http://test/hubs"), TransportType.LongPolling, loggerFactory, _testServer.CreateHandler());
-            var connection = new HubConnection(httpConnection, loggerFactory);
+            var connection = new HubConnection(httpConnection, protocol, loggerFactory);
             try
             {
                 await connection.StartAsync();
@@ -137,13 +144,14 @@ namespace Microsoft.AspNetCore.SignalR.Client.FunctionalTests
             }
         }
 
-        [Fact]
+        [Theory]
-        public async Task CanStreamClientMethodFromServer()
+        [MemberData(nameof(HubProtocols))]
+        public async Task CanStreamClientMethodFromServer(IHubProtocol protocol)
         {
             var loggerFactory = CreateLogger();
 
             var httpConnection = new HttpConnection(new Uri("http://test/hubs"), TransportType.LongPolling, loggerFactory, _testServer.CreateHandler());
-            var connection = new HubConnection(httpConnection, loggerFactory);
+            var connection = new HubConnection(httpConnection, protocol, loggerFactory);
             try
             {
                 await connection.StartAsync();
@@ -160,13 +168,14 @@ namespace Microsoft.AspNetCore.SignalR.Client.FunctionalTests
             }
         }
 
-        [Fact]
+        [Theory]
-        public async Task ServerClosesConnectionIfHubMethodCannotBeResolved()
+        [MemberData(nameof(HubProtocols))]
+        public async Task ServerClosesConnectionIfHubMethodCannotBeResolved(IHubProtocol hubProtocol)
         {
             var loggerFactory = CreateLogger();
 
             var httpConnection = new HttpConnection(new Uri("http://test/hubs"), TransportType.LongPolling, loggerFactory, _testServer.CreateHandler());
-            var connection = new HubConnection(httpConnection, loggerFactory);
+            var connection = new HubConnection(httpConnection, hubProtocol, loggerFactory);
             try
             {
                 await connection.StartAsync();
@@ -182,6 +191,13 @@ namespace Microsoft.AspNetCore.SignalR.Client.FunctionalTests
             }
         }
 
+        public static IEnumerable<object[]> HubProtocols() =>
+            new[]
+            {
+                new object[] { new JsonHubProtocol(new JsonSerializer()) },
+                new object[] { new MessagePackHubProtocol() },
+            };
+
         public void Dispose()
         {
             _testServer.Dispose();

test/Microsoft.AspNetCore.SignalR.Client.Tests/HubConnectionProtocolTests.cs

@@ -17,6 +17,25 @@ namespace Microsoft.AspNetCore.SignalR.Client.Tests
     // don't cause problems.
     public class HubConnectionProtocolTests
     {
+        [Fact]
+        public async Task ClientSendsNegotationMessageWhenStartingConnection()
+        {
+            var connection = new TestConnection();
+            var hubConnection = new HubConnection(connection, new JsonHubProtocol(new JsonSerializer()), new LoggerFactory());
+            try
+            {
+                await hubConnection.StartAsync();
+                var negotiationMessage = await connection.ReadSentTextMessageAsync().OrTimeout();
+
+                Assert.Equal("19:{\"protocol\":\"json\"};", negotiationMessage);
+            }
+            finally
+            {
+                await hubConnection.DisposeAsync().OrTimeout();
+                await connection.DisposeAsync().OrTimeout();
+            }
+        }
+
         [Fact]
         public async Task InvokeSendsAnInvocationMessage()
         {
@@ -28,6 +47,8 @@ namespace Microsoft.AspNetCore.SignalR.Client.Tests
 
                 var invokeTask = hubConnection.Invoke("Foo");
 
+                // skip negotiation
+                await connection.ReadSentTextMessageAsync().OrTimeout();
                 var invokeMessage = await connection.ReadSentTextMessageAsync().OrTimeout();
 
                 Assert.Equal("59:{\"invocationId\":\"1\",\"type\":1,\"target\":\"Foo\",\"arguments\":[]};", invokeMessage);
@@ -50,6 +71,8 @@ namespace Microsoft.AspNetCore.SignalR.Client.Tests
 
                 var channel = hubConnection.Stream<object>("Foo");
 
+                // skip negotiation
+                await connection.ReadSentTextMessageAsync().OrTimeout();
                 var invokeMessage = await connection.ReadSentTextMessageAsync().OrTimeout();
 
                 Assert.Equal("59:{\"invocationId\":\"1\",\"type\":1,\"target\":\"Foo\",\"arguments\":[]};", invokeMessage);

test/Microsoft.AspNetCore.SignalR.Client.Tests/HubConnectionTests.cs

@@ -2,7 +2,6 @@
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
 using System;
-using System.Buffers;
 using System.Collections.Generic;
 using System.IO;
 using System.Threading.Tasks;
@@ -174,6 +173,8 @@ namespace Microsoft.AspNetCore.SignalR.Client.Tests
                 };
             }
 
+            public string Name { get => "MockHubProtocol"; }
+
             public bool TryParseMessages(ReadOnlySpan<byte> input, IInvocationBinder binder, out IList<HubMessage> messages)
             {
                 messages = new List<HubMessage>();

test/Microsoft.AspNetCore.SignalR.Client.Tests/TestConnection.cs

@@ -3,7 +3,6 @@
 
 using System;
 using System.IO;
-using System.Net.Http;
 using System.Text;
 using System.Threading;
 using System.Threading.Tasks;

test/Microsoft.AspNetCore.SignalR.Common.Tests/Internal/Protocol/NegotiationProtocolTests.cs

@@ -0,0 +1,45 @@
+// Copyright (c) .NET Foundation. All rights reserved.
+// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
+
+using System;
+using System.IO;
+using System.Text;
+using Microsoft.AspNetCore.SignalR.Internal.Protocol;
+using Xunit;
+
+namespace Microsoft.AspNetCore.SignalR.Common.Tests.Internal.Protocol
+{
+    public class NegotiationProtocolTests
+    {
+        [Fact]
+        public void CanRoundtripNegotiation()
+        {
+            var negotiationMessage = new NegotiationMessage(protocol: "dummy");
+            using (var ms = new MemoryStream())
+            {
+                Assert.True(NegotiationProtocol.TryWriteProtocolNegotiationMessage(negotiationMessage, ms));
+                Assert.True(NegotiationProtocol.TryReadProtocolNegotiationMessage(ms.ToArray(), out var deserializedMessage));
+
+                Assert.NotNull(deserializedMessage);
+                Assert.Equal(negotiationMessage.Protocol, deserializedMessage.Protocol);
+            }
+        }
+
+        [Theory]
+        [InlineData("2:", "Unable to parse payload as a negotiation message.")]
+        [InlineData("2:42;", "Unexpected JSON Token Type 'Integer'. Expected a JSON Object.")]
+        [InlineData("4:\"42\";", "Unexpected JSON Token Type 'String'. Expected a JSON Object.")]
+        [InlineData("4:null;", "Unexpected JSON Token Type 'Null'. Expected a JSON Object.")]
+        [InlineData("2:{};", "Missing required property 'protocol'.")]
+        [InlineData("2:[];", "Unexpected JSON Token Type 'Array'. Expected a JSON Object.")]
+        public void ParsingNegotiationMessageThrowsForInvalidMessages(string payload, string expectedMessage)
+        {
+            var message = Encoding.UTF8.GetBytes(payload);
+
+            var exception = Assert.Throws<FormatException>(() =>
+                Assert.True(NegotiationProtocol.TryReadProtocolNegotiationMessage(message, out var deserializedMessage)));
+
+            Assert.Equal(expectedMessage, exception.Message);
+        }
+    }
+}

test/Microsoft.AspNetCore.SignalR.Tests/Internal/DefaultHubProtocolResolverTests.cs

@@ -0,0 +1,46 @@
+// Copyright (c) .NET Foundation. All rights reserved.
+// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
+
+using System;
+using System.Collections.Generic;
+using Microsoft.AspNetCore.SignalR.Internal;
+using Microsoft.AspNetCore.SignalR.Internal.Protocol;
+using Microsoft.AspNetCore.Sockets;
+using Moq;
+using Newtonsoft.Json;
+using Xunit;
+
+namespace Microsoft.AspNetCore.SignalR.Common.Protocol.Tests
+{
+    public class DefaultHubProtocolResolverTests
+    {
+        [Theory]
+        [MemberData(nameof(HubProtocols))]
+        public void DefaultHubProtocolResolverTestsCanCreateSupportedProtocols(IHubProtocol protocol)
+        {
+            var mockConnection = new Mock<ConnectionContext>();
+            Assert.IsType(
+                protocol.GetType(),
+                new DefaultHubProtocolResolver().GetProtocol(protocol.Name, mockConnection.Object));
+        }
+
+        [Theory]
+        [InlineData(null)]
+        [InlineData("dummy")]
+        public void DefaultHubProtocolResolverThrowsForNotSupportedProtocol(string protocolName)
+        {
+            var mockConnection = new Mock<ConnectionContext>();
+            var exception = Assert.Throws<NotSupportedException>(
+                () => new DefaultHubProtocolResolver().GetProtocol(protocolName, mockConnection.Object));
+
+            Assert.Equal($"The protocol '{protocolName ?? "(null)"}' is not supported.", exception.Message);
+        }
+
+        public static IEnumerable<object[]> HubProtocols() =>
+            new[]
+            {
+                new object[] { new JsonHubProtocol(new JsonSerializer()) },
+                new object[] { new MessagePackHubProtocol() },
+            };
+    }
+}

test/Microsoft.AspNetCore.SignalR.Tests/TestClient.cs

@@ -3,6 +3,7 @@
 
 using System;
 using System.Collections.Generic;
+using System.IO;
 using System.Security.Claims;
 using System.Threading;
 using System.Threading.Tasks;
@@ -41,6 +42,12 @@ namespace Microsoft.AspNetCore.SignalR.Tests
             _protocol = new JsonHubProtocol(new JsonSerializer());
 
             _cts = new CancellationTokenSource();
+
+            using (var memoryStream = new MemoryStream())
+            {
+                NegotiationProtocol.TryWriteProtocolNegotiationMessage(new NegotiationMessage(_protocol.Name), memoryStream);
+                Application.Out.TryWrite(memoryStream.ToArray());
+            }
         }
 
         public async Task<IList<HubMessage>> StreamAsync(string methodName, params object[] args)