Adding IConnection interface

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

@@ -19,7 +19,7 @@ namespace Microsoft.AspNetCore.SignalR.Client
     public class HubConnection
     {
         private readonly ILogger _logger;
-        private readonly Connection _connection;
+        private readonly IConnection _connection;
         private readonly IInvocationAdapter _adapter;
         private readonly HubBinder _binder;
 
@@ -46,6 +46,10 @@ namespace Microsoft.AspNetCore.SignalR.Client
         }
 
         public HubConnection(Uri url, IInvocationAdapter adapter, ILoggerFactory loggerFactory)
+            : this(new Connection(url, loggerFactory), adapter, loggerFactory)
+        { }
+
+        public HubConnection(IConnection connection, IInvocationAdapter adapter, ILoggerFactory loggerFactory)
         {
             // TODO: loggerFactory shouldn't be required
             if (loggerFactory == null)
@@ -53,8 +57,14 @@ namespace Microsoft.AspNetCore.SignalR.Client
                 throw new ArgumentNullException(nameof(loggerFactory));
             }
 
+            if (connection == null)
+            {
+                throw new ArgumentNullException(nameof(connection));
+            }
+
+            _connection = connection;
+
             _binder = new HubBinder(this);
-            _connection = new Connection(url, loggerFactory);
             _adapter = adapter;
             _logger = loggerFactory.CreateLogger<HubConnection>();
 

src/Microsoft.AspNetCore.Sockets.Client/Connection.cs

@@ -12,7 +12,7 @@ using Microsoft.Extensions.Logging;
 
 namespace Microsoft.AspNetCore.Sockets.Client
 {
-    public class Connection
+    public class Connection: IConnection
     {
         private readonly ILoggerFactory _loggerFactory;
         private readonly ILogger _logger;

src/Microsoft.AspNetCore.Sockets.Client/IConnection.cs

@@ -0,0 +1,21 @@
+// 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.Net.Http;
+using System.Threading;
+using System.Threading.Tasks;
+
+namespace Microsoft.AspNetCore.Sockets.Client
+{
+    public interface IConnection
+    {
+        Task StartAsync(ITransport transport, HttpClient httpClient);
+        Task<bool> SendAsync(byte[] data, MessageType type, CancellationToken cancellationToken);
+        Task DisposeAsync();
+
+        event Action Connected;
+        event Action<byte[], MessageType> Received;
+        event Action<Exception> Closed;
+    }
+}

src/Microsoft.AspNetCore.Sockets.Client/WebSocketsTransport.cs

@@ -42,7 +42,7 @@ namespace Microsoft.AspNetCore.Sockets.Client
             {
                 throw new ArgumentNullException(nameof(application));
             }
-            
+
             _application = application;
 
             await Connect(url);

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

@@ -18,7 +18,7 @@ namespace Microsoft.AspNetCore.SignalR.Client.Tests
         public void CannotCreateHubConnectionWithNullUrl()
         {
             var exception = Assert.Throws<ArgumentNullException>(
-                () => new HubConnection(null, Mock.Of<IInvocationAdapter>(), Mock.Of<ILoggerFactory>()));
+                () => new HubConnection((Uri)null, Mock.Of<IInvocationAdapter>(), Mock.Of<ILoggerFactory>()));
             Assert.Equal("url", exception.ParamName);
         }