camelCasing objects serialized by JsonHubProtocol

Fixes: #859

samples/ChatSample/Views/Home/Index.cshtml

@@ -35,15 +35,15 @@ connection.on('SetUsersOnline', usersOnline => {
 
 connection.on('UsersJoined', users => {
     users.forEach(user => {
-        appendLine('User ' + user.Name + ' joined the chat');
+        appendLine('User ' + user.name + ' joined the chat');
         addUserOnline(user);
     });
 });
 
 connection.on('UsersLeft', users => {
     users.forEach(user => {
-        appendLine('User ' + user.Name + ' left the chat');
-        document.getElementById(user.ConnectionId).outerHTML = '';
+        appendLine('User ' + user.name + ' left the chat');
+        document.getElementById(user.connectionId).outerHTML = '';
     });
 });
 
@@ -78,12 +78,12 @@ function appendLine(line, color) {
 };
 
 function addUserOnline(user) {
-    if (document.getElementById(user.ConnectionId)) {
+    if (document.getElementById(user.connectionId)) {
         return;
     }
     var userLi = document.createElement('li');
-    userLi.innerText = `${user.Name} (${user.ConnectionId})`;
-    userLi.id = user.ConnectionId;
+    userLi.innerText = `${user.name} (${user.connectionId})`;
+    userLi.id = user.connectionId;
     document.getElementById('users').appendChild(userLi);
 }
 

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

@@ -7,6 +7,7 @@ using System.IO;
 using Microsoft.AspNetCore.SignalR.Internal.Formatters;
 using Newtonsoft.Json;
 using Newtonsoft.Json.Linq;
+using Newtonsoft.Json.Serialization;
 
 namespace Microsoft.AspNetCore.SignalR.Internal.Protocol
 {
@@ -34,7 +35,7 @@ namespace Microsoft.AspNetCore.SignalR.Internal.Protocol
         /// NOT be changed using this serializer.
         /// </summary>
         public JsonHubProtocol()
-            : this(new JsonSerializer())
+            : this(JsonSerializer.Create(CreateDefaultSerializerSettings()))
         { }
 
         /// <summary>
@@ -258,5 +259,10 @@ namespace Microsoft.AspNetCore.SignalR.Internal.Protocol
                 return new CompletionMessage(invocationId, error, result: payload, hasResult: true);
             }
         }
+
+        public static JsonSerializerSettings CreateDefaultSerializerSettings()
+        {
+            return new JsonSerializerSettings { ContractResolver = new CamelCasePropertyNamesContractResolver() };
+        }
     }
 }

src/Microsoft.AspNetCore.SignalR.Core/HubOptions.cs

@@ -9,7 +9,7 @@ namespace Microsoft.AspNetCore.SignalR
 {
     public class HubOptions
     {
-        public JsonSerializerSettings JsonSerializerSettings { get; set; } = new JsonSerializerSettings();
+        public JsonSerializerSettings JsonSerializerSettings { get; set; } = JsonHubProtocol.CreateDefaultSerializerSettings();
         public SerializationContext MessagePackSerializationContext { get; set; } = MessagePackHubProtocol.CreateDefaultSerializationContext();
     }
 }

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

@@ -1008,7 +1008,7 @@ namespace Microsoft.AspNetCore.SignalR.Tests
                 {
                     o.JsonSerializerSettings = new JsonSerializerSettings
                     {
-                        ContractResolver = new CamelCasePropertyNamesContractResolver()
+                        ContractResolver = new DefaultContractResolver()
                     };
                 });
             });
@@ -1026,7 +1026,34 @@ namespace Microsoft.AspNetCore.SignalR.Tests
                 var message = (InvocationMessage)await client.ReadAsync().OrTimeout();
 
                 var customItem = message.Arguments[0].ToString();
-                // Originally "Message" and "paramName"
+                // by default properties serialized by JsonHubProtocol are using camelCasing
+                Assert.Contains("Message", customItem);
+                Assert.Contains("paramName", customItem);
+
+                client.Dispose();
+
+                await endPointLifetime.OrTimeout();
+            }
+        }
+
+        [Fact]
+        public async Task JsonHubProtocolUsesCamelCasingByDefault()
+        {
+            var serviceProvider = CreateServiceProvider();
+            var endPoint = serviceProvider.GetService<HubEndPoint<MethodHub>>();
+
+            using (var client = new TestClient())
+            {
+                var endPointLifetime = endPoint.OnConnectedAsync(client.Connection);
+
+                await client.Connected.OrTimeout();
+
+                await client.SendInvocationAsync(nameof(MethodHub.BroadcastItem)).OrTimeout();
+
+                var message = (InvocationMessage)await client.ReadAsync().OrTimeout();
+
+                var customItem = message.Arguments[0].ToString();
+                // originally Message, paramName
                 Assert.Contains("message", customItem);
                 Assert.Contains("paramName", customItem);