Made some changes to better abstract BufferTextWriter.

- Added BinaryTextWriter which is a buffer text writer that supports writing array segments.
- Updated tests.
- Added tests for forever frame encoding full messages.

src/Microsoft.AspNet.SignalR.Core/Infrastructure/BinaryTextWriter.cs

@@ -0,0 +1,34 @@
+using System;
+using Microsoft.AspNet.SignalR.Hosting;
+
+namespace Microsoft.AspNet.SignalR.Infrastructure
+{
+    /// <summary>
+    /// A buffering text writer that supports writing binary directly as well
+    /// </summary>
+    internal unsafe class BinaryTextWriter : BufferTextWriter, IBinaryWriter
+    {
+        public BinaryTextWriter(IResponse response) :
+            base((data, state) => ((IResponse)state).Write(data), response, reuseBuffers: true, bufferSize: 128)
+        {
+
+        }
+
+        public BinaryTextWriter(IWebSocket socket) :
+            base((data, state) => ((IWebSocket)state).SendChunk(data), socket, reuseBuffers: false, bufferSize: 1024)
+        {
+
+        }
+
+
+        public BinaryTextWriter(Action<ArraySegment<byte>, object> write, object state, bool reuseBuffers, int bufferSize) :
+            base(write, state, reuseBuffers, bufferSize)
+        {
+        }
+
+        public void Write(ArraySegment<byte> data)
+        {
+            Writer.Write(data);
+        }
+    }
+}

src/Microsoft.AspNet.SignalR.Core/Infrastructure/BufferTextWriter.cs

@@ -13,7 +13,7 @@ namespace Microsoft.AspNet.SignalR.Infrastructure
     /// we don't need to write to a long lived buffer. This saves massive amounts of memory
     /// as the number of connections grows.
     /// </summary>
-    internal unsafe class BufferTextWriter : TextWriter, IBinaryWriter
+    internal abstract unsafe class BufferTextWriter : TextWriter
     {
         private readonly Encoding _encoding;
 
@@ -37,7 +37,7 @@ internal unsafe class BufferTextWriter : TextWriter, IBinaryWriter
         }
 
         [SuppressMessage("Microsoft.Globalization", "CA1305:SpecifyIFormatProvider", MessageId = "System.IO.TextWriter.#ctor", Justification = "It won't be used")]
-        public BufferTextWriter(Action<ArraySegment<byte>, object> write, object state, bool reuseBuffers, int bufferSize)
+        protected BufferTextWriter(Action<ArraySegment<byte>, object> write, object state, bool reuseBuffers, int bufferSize)
         {
             _write = write;
             _writeState = state;
@@ -46,7 +46,7 @@ public BufferTextWriter(Action<ArraySegment<byte>, object> write, object state,
             _bufferSize = bufferSize;
         }
 
-        private ChunkedWriter Writer
+        protected internal ChunkedWriter Writer
         {
             get
             {
@@ -79,17 +79,12 @@ public override void Write(char value)
             Writer.Write(value);
         }
 
-        public void Write(ArraySegment<byte> data)
-        {
-            Writer.Write(data);
-        }
-
         public override void Flush()
         {
             Writer.Flush();
         }
 
-        private class ChunkedWriter
+        internal class ChunkedWriter
         {
             private int _charPos;
             private int _charLen;

src/Microsoft.AspNet.SignalR.Core/Infrastructure/Connection.cs

@@ -145,7 +145,7 @@ private ArraySegment<byte> GetMessageBuffer(object value)
         {
             using (var stream = new MemoryStream(128))
             {
-                var bufferWriter = new BufferTextWriter((buffer, state) =>
+                var bufferWriter = new BinaryTextWriter((buffer, state) =>
                 {
                     ((MemoryStream)state).Write(buffer.Array, buffer.Offset, buffer.Count);
                 },

src/Microsoft.AspNet.SignalR.Core/Microsoft.AspNet.SignalR.Core.csproj

@@ -67,6 +67,7 @@
     <Compile Include="Infrastructure\AckHandler.cs" />
     <Compile Include="Configuration\DefaultConfigurationManager.cs" />
     <Compile Include="Infrastructure\ArraySegmentTextReader.cs" />
+    <Compile Include="Infrastructure\BinaryTextWriter.cs" />
     <Compile Include="Infrastructure\ConnectionManager.cs" />
     <Compile Include="ConnectionMessage.cs" />
     <Compile Include="Infrastructure\DefaultProtectedData.cs" />

src/Microsoft.AspNet.SignalR.Core/Transports/PersistentResponse.cs

@@ -20,7 +20,7 @@ public sealed class PersistentResponse : IJsonWritable
         private readonly Action<TextWriter> _writeCursor;
 
         public PersistentResponse()
-            : this(message => true, writer => { })
+            : this(message => false, writer => { })
         {
 
         }

src/Microsoft.AspNet.SignalR.Core/Transports/TransportDisconnectBase.cs

@@ -186,7 +186,7 @@ public Uri Url
 
         protected virtual TextWriter CreateResponseWriter()
         {
-            return new BufferTextWriter(Context.Response);
+            return new BinaryTextWriter(Context.Response);
         }
 
         protected void IncrementErrors()

src/Microsoft.AspNet.SignalR.Core/Transports/WebSocketTransport.cs

@@ -95,7 +95,7 @@ public override Task ProcessRequest(ITransportConnection connection)
 
         protected override TextWriter CreateResponseWriter()
         {
-            return new BufferTextWriter(_socket);
+            return new BinaryTextWriter(_socket);
         }
 
         public override Task Send(object value)

tests/Microsoft.AspNet.SignalR.Tests/BufferTextWriterFacts.cs

@@ -13,7 +13,7 @@ public class BufferTextWriterFacts
         public void CanEncodingSurrogatePairsCorrectly()
         {
             var bytes = new List<byte>();
-            var writer = new BufferTextWriter((buffer, state) =>
+            var writer = new BinaryTextWriter((buffer, state) =>
             {
                 for (int i = buffer.Offset; i < buffer.Count; i++)
                 {
@@ -34,7 +34,7 @@ public void CanEncodingSurrogatePairsCorrectly()
         public void WriteNewBufferIsUsedForWritingChunksIfReuseBuffersFalse()
         {
             var buffers = new List<ArraySegment<byte>>();
-            var writer = new BufferTextWriter((buffer, state) =>
+            var writer = new BinaryTextWriter((buffer, state) =>
             {
                 buffers.Add(buffer);
             },
@@ -55,7 +55,7 @@ public void WriteNewBufferIsUsedForWritingChunksIfReuseBuffersFalse()
         public void WriteSameBufferIsUsedForWritingChunksIfReuseBuffersTrue()
         {
             var buffers = new List<ArraySegment<byte>>();
-            var writer = new BufferTextWriter((buffer, state) =>
+            var writer = new BinaryTextWriter((buffer, state) =>
             {
                 buffers.Add(buffer);
             },
@@ -79,7 +79,7 @@ public void WritesInChunks()
             int size = 3000;
 
             var buffers = new List<ArraySegment<byte>>();
-            var writer = new BufferTextWriter((buffer, state) =>
+            var writer = new BinaryTextWriter((buffer, state) =>
             {
                 buffers.Add(buffer);
             },
@@ -121,7 +121,7 @@ private IEnumerable<int> GetChunks(int size, int bufferSize)
         public void CanInterleaveStringsAndRawBinary()
         {
             var buffers = new List<ArraySegment<byte>>();
-            var writer = new BufferTextWriter((buffer, state) =>
+            var writer = new BinaryTextWriter((buffer, state) =>
             {
                 buffers.Add(buffer);
             },

tests/Microsoft.AspNet.SignalR.Tests/Core/Transports/ForeverFrameTransportFacts.cs

@@ -1,9 +1,12 @@
 using System;
+using System.Collections.Generic;
 using System.Collections.Specialized;
 using System.IO;
+using System.Text;
 using System.Threading;
 using System.Threading.Tasks;
 using Microsoft.AspNet.SignalR.Hosting;
+using Microsoft.AspNet.SignalR.Messaging;
 using Microsoft.AspNet.SignalR.Transports;
 using Moq;
 using Xunit;
@@ -13,17 +16,31 @@ namespace Microsoft.AspNet.SignalR.Tests.Core
 {
     public class ForeverFrameTransportFacts
     {
-        [Fact]
-        public void ForeverFrameTransportEscapesTags()
+        [Theory]
+        [InlineData("</sCRiPT>", "\\u003c/sCRiPT\\u003e")]
+        [InlineData("</SCRIPT dosomething='false'>", "\\u003c/SCRIPT dosomething='false'\\u003e")]
+        [InlineData("<p>ELLO</p>", "\\u003cp\\u003eELLO\\u003c/p\\u003e")]
+        public void ForeverFrameTransportEscapesTags(string data, string expected)
+        {
+            var request = new Mock<IRequest>();
+            var response = new CustomResponse();
+            var context = new HostContext(request.Object, response);
+            var fft = new ForeverFrameTransport(context, new DefaultDependencyResolver());
+
+            AssertEscaped(fft, response, data, expected);
+        }
+
+        [Theory]
+        [InlineData("<script type=\"\"></script>", "\\u003cscript type=\"\"\\u003e\\u003c/script\\u003e")]
+        [InlineData("<script type=''></script>", "\\u003cscript type=''\\u003e\\u003c/script\\u003e")]
+        public void ForeverFrameTransportEscapesTagsWithPersistentResponse(string data, string expected)
         {
             var request = new Mock<IRequest>();
             var response = new CustomResponse();
             var context = new HostContext(request.Object, response);
             var fft = new ForeverFrameTransport(context, new DefaultDependencyResolver());
 
-            AssertEscaped(fft, response, "</sCRiPT>", "\\u003c/sCRiPT\\u003e");
-            AssertEscaped(fft, response, "</SCRIPT dosomething='false'>", "\\u003c/SCRIPT dosomething='false'\\u003e");
-            AssertEscaped(fft, response, "<p>ELLO</p>", "\\u003cp\\u003eELLO\\u003c/p\\u003e");
+            AssertEscaped(fft, response, GetWrappedResponse(data), expected);
         }
 
         [Theory]
@@ -42,7 +59,7 @@ public void ForeverFrameTransportThrowsOnInvalidFrameId(string frameId)
             var context = new HostContext(request.Object, response);
             var connection = new Mock<ITransportConnection>();
             var fft = new ForeverFrameTransport(context, new DefaultDependencyResolver());
-            
+
             Assert.Throws(typeof(InvalidOperationException), () => fft.InitializeResponse(connection.Object));
         }
 
@@ -62,7 +79,7 @@ public void ForeverFrameTransportSetsCorrectContentType()
             Assert.Equal("text/html; charset=UTF-8", response.ContentType);
         }
 
-        private static void AssertEscaped(ForeverFrameTransport fft, CustomResponse response, string input, string expectedOutput)
+        private static void AssertEscaped(ForeverFrameTransport fft, CustomResponse response, object input, string expectedOutput)
         {
             fft.Send(input).Wait();
 
@@ -73,6 +90,22 @@ private static void AssertEscaped(ForeverFrameTransport fft, CustomResponse resp
             Assert.True(rawResponse.Contains(expectedOutput));
         }
 
+        private static PersistentResponse GetWrappedResponse(string raw)
+        {
+            var data = Encoding.Default.GetBytes(raw);
+            var message = new Message("foo", "key", new ArraySegment<byte>(data));
+
+            var response = new PersistentResponse
+            {
+                Messages = new List<ArraySegment<Message>> 
+                {
+                    new ArraySegment<Message>(new Message[] { message })
+                }
+            };
+
+            return response;
+        }
+
         private class CustomResponse : IResponse
         {
             private MemoryStream _stream;