Consolidate formatting for http request and response types.

src/Microsoft.DotNet.Interactive.ApiCompatibility.Tests/ApiCompatibilityTests.httpRequest_api_is_not_changed.approved.txt

@@ -27,3 +27,5 @@ Microsoft.DotNet.Interactive.HttpRequest
     public HttpRequest Request { get;}
     public System.Int32 StatusCode { get;}
     public System.String Version { get;}
+  public static class HttpResponseMessageFormattingExtensions
+    public static System.Void RegisterFormatters()

src/Microsoft.DotNet.Interactive.AspNetCore.Tests/AspNetCoreTests.cs

@@ -7,6 +7,7 @@
 using Microsoft.DotNet.Interactive.Commands;
 using Microsoft.DotNet.Interactive.CSharp;
 using Microsoft.DotNet.Interactive.Events;
+using Microsoft.DotNet.Interactive.HttpRequest;
 using Microsoft.DotNet.Interactive.Tests.Utility;
 using Xunit;
 
@@ -25,6 +26,8 @@ public AspNetCoreTests()
 
         var loadTask = new AspNetCoreKernelExtension().OnLoadAsync(_kernel);
         Assert.Same(Task.CompletedTask, loadTask);
+
+        HttpResponseMessageFormattingExtensions.RegisterFormatters();
     }
 
     public void Dispose()

src/Microsoft.DotNet.Interactive.AspNetCore.Tests/Microsoft.DotNet.Interactive.AspNetCore.Tests.csproj

@@ -26,6 +26,7 @@
     <ProjectReference Include="..\dotnet-interactive\dotnet-interactive.csproj" />
     <ProjectReference Include="..\interface-generator\interface-generator.csproj" />
     <ProjectReference Include="..\Microsoft.DotNet.Interactive.AspNetCore\Microsoft.DotNet.Interactive.AspNetCore.csproj" />
+    <ProjectReference Include="..\Microsoft.DotNet.Interactive.HttpRequest\Microsoft.DotNet.Interactive.HttpRequest.csproj" />
     <ProjectReference Include="..\Microsoft.DotNet.Interactive.Tests\Microsoft.DotNet.Interactive.Tests.csproj" />
   </ItemGroup>
 

src/Microsoft.DotNet.Interactive.AspNetCore/AspNetCoreCSharpKernelExtensions.cs

@@ -22,7 +22,7 @@ namespace Microsoft.DotNet.Interactive.AspNetCore;
 
 public static class AspNetCoreCSharpKernelExtensions
 {
-    private static readonly Assembly[] _references = 
+    private static readonly Assembly[] _references =
     {
         typeof(Host).Assembly, // Microsoft.Extensions.Hosting
         typeof(WebHost).Assembly, // Microsoft.AspNetCore
@@ -37,7 +37,7 @@ public static class AspNetCoreCSharpKernelExtensions
         typeof(IEndpointRouteBuilder).Namespace, // Microsoft.AspNetCore.Routing
         typeof(EndpointRouteBuilderExtensions).Namespace, // Microsoft.AspNetCore.Builder
         typeof(InteractiveEndpointRouteBuilderExtensions).Namespace, // Microsoft.DotNet.Interactive.AspNetCore
-        typeof(HttpClient).Namespace, // System.Net.Htttp
+        typeof(HttpClient).Namespace, // System.Net.Http
     };
 
     public static CSharpKernel UseAspNetCore(this CSharpKernel kernel)
@@ -48,7 +48,7 @@ public static CSharpKernel UseAspNetCore(this CSharpKernel kernel)
         {
             Handler = CommandHandler.Create(async () =>
             {
-                if (interactiveHost is {})
+                if (interactiveHost is { })
                 {
                     return;
                 }

src/Microsoft.DotNet.Interactive.Formatting/HtmlFormatter.cs

@@ -6,11 +6,9 @@
 using System.Collections.Generic;
 using System.Dynamic;
 using System.Linq;
-using System.Net.Http;
 using System.Numerics;
 using System.Text.Encodings.Web;
 using System.Text.Json;
-using System.Threading;
 using Microsoft.AspNetCore.Html;
 using static Microsoft.DotNet.Interactive.Formatting.PocketViewTags;
 
@@ -44,7 +42,7 @@ internal static ITypeFormatter GetDefaultFormatterForAnyEnumerable(Type type) =>
         FormattersForAnyEnumerable.GetOrCreateFormatterForType(type);
 
     internal static void FormatAndStyleAsPlainText(
-        object value, 
+        object value,
         FormatContext context)
     {
         context.RequireDefaultStyles();
@@ -160,7 +158,7 @@ type.Namespace is not null &&
                 var typeLookupName =
                     genericTypeDefinition.FullName.ToLower().Replace("+",".").Replace("`","-");
 
-                PocketView view = 
+                PocketView view =
                     span(a[href: $"https://docs.microsoft.com/dotnet/api/{typeLookupName}?view=net-7.0"](
                         text));
                 view.WriteTo(context);
@@ -314,22 +312,6 @@ type.Namespace is not null &&
 
             view.WriteTo(context);
 
-            return true;
-        }),
-
-        new HtmlFormatter<HttpResponseMessage>((value, context) =>
-        {
-            // Prevent SynchronizationContext-induced deadlocks given the following sync-over-async code.
-            ExecutionContext.SuppressFlow();
-            try
-            {
-                value.FormatAsHtml(context).Wait();
-            }
-            finally
-            {
-                ExecutionContext.RestoreFlow();
-            }
-
             return true;
         })
     };

src/Microsoft.DotNet.Interactive.Formatting/PlainTextFormatter.cs

@@ -6,13 +6,11 @@
 using System.Collections.Generic;
 using System.Dynamic;
 using System.Linq;
-using System.Net.Http;
 using System.Numerics;
 using System.Reflection;
 using System.Text.Encodings.Web;
 using System.Text.Json;
 using System.Text.RegularExpressions;
-using System.Threading;
 
 using Microsoft.AspNetCore.Html;
 using Microsoft.DotNet.Interactive.CSharp;
@@ -38,7 +36,7 @@ internal static FormatDelegate<T> CreateFormatDelegate<T>(MemberInfo[] forMember
     {
         var accessors = forMembers.GetMemberAccessors<T>().ToArray();
 
-        if (Formatter<T>.TypeIsValueTuple || 
+        if (Formatter<T>.TypeIsValueTuple ||
             Formatter<T>.TypeIsTuple)
         {
             return FormatTuple;
@@ -195,9 +193,9 @@ bool FormatTuple(T target, FormatContext context)
             return true;
         }),
 
-        new PlainTextFormatter<ReadOnlyMemory<char>>((memory, context) => 
+        new PlainTextFormatter<ReadOnlyMemory<char>>((memory, context) =>
         {
-            context.Writer.Write(memory.Span.ToString()); 
+            context.Writer.Write(memory.Span.ToString());
             return true;
         }),
 
@@ -236,7 +234,7 @@ bool FormatTuple(T target, FormatContext context)
                                                var array = toArray.Invoke(null, new[] { obj });
 
                                                array.FormatTo(context, PlainTextFormatter.MimeType);
-                        
+
                                                return true;
                                            }),
 
@@ -273,23 +271,6 @@ bool FormatTuple(T target, FormatContext context)
             return true;
         }),
 
-        new PlainTextFormatter<HttpResponseMessage>((value, context) =>
-            {
-                // Formatter.Register() doesn't support async formatters yet.
-                // Prevent SynchronizationContext-induced deadlocks given the following sync-over-async code.
-                ExecutionContext.SuppressFlow();
-                try
-                {
-                    value.FormatAsPlainText(context).Wait();
-                }
-                finally
-                {
-                    ExecutionContext.RestoreFlow();
-                }
-
-                return true;
-        }),
-
         // Fallback for any object
         new PlainTextFormatter<object>((obj, context) =>
         {
@@ -304,7 +285,7 @@ bool FormatTuple(T target, FormatContext context)
         })
     };
 
-    private static string IndentAtNewLines(this string s, FormatContext context) => 
+    private static string IndentAtNewLines(this string s, FormatContext context) =>
         Regex.Replace(s, @"^\s+", new string(' ', (context.Depth + 1) * NumberOfSpacesToIndent), RegexOptions.Multiline);
 
     internal static void WriteIndent(FormatContext context, string bonus = "    ")

src/Microsoft.DotNet.Interactive.HttpRequest/Formatting/HttpResponseFormatterSource.cs

@@ -0,0 +1,38 @@
+// Copyright (c) .NET Foundation and contributors. All rights reserved.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+
+using System.Collections.Generic;
+using Microsoft.DotNet.Interactive.Formatting;
+
+namespace Microsoft.DotNet.Interactive.HttpRequest;
+
+internal sealed class HttpResponseFormatterSource : ITypeFormatterSource
+{
+    IEnumerable<ITypeFormatter> ITypeFormatterSource.CreateTypeFormatters()
+    {
+        yield return new HttpResponseHtmlFormatter();
+        yield return new HttpResponsePlainTextFormatter();
+    }
+
+    private sealed class HttpResponseHtmlFormatter : TypeFormatter<HttpResponse>
+    {
+        public override string MimeType => HtmlFormatter.MimeType;
+
+        public override bool Format(HttpResponse value, FormatContext context)
+        {
+            value.FormatAsHtml(context);
+            return true;
+        }
+    }
+
+    private sealed class HttpResponsePlainTextFormatter : TypeFormatter<HttpResponse>
+    {
+        public override string MimeType => PlainTextFormatter.MimeType;
+
+        public override bool Format(HttpResponse value, FormatContext context)
+        {
+            value.FormatAsPlainText(context);
+            return true;
+        }
+    }
+}

src/Microsoft.DotNet.Interactive.HttpRequest/HttpResponseFormattingExtensions.cs → src/Microsoft.DotNet.Interactive.HttpRequest/Formatting/HttpResponseFormattingExtensions.cs

@@ -39,8 +39,15 @@ internal static class HttpResponseFormattingExtensions
                 font-weight: 700;
             }}");
 
-    internal static void FormatAsHtml(this HttpResponse response, FormatContext context)
+    internal static void FormatAsHtml(this HttpResponse? response, FormatContext context)
     {
+        if (response is null)
+        {
+            PocketView result = PocketViewTags.pre("null");
+            result.WriteTo(context);
+            return;
+        }
+
         dynamic? requestDiv;
         if (response.Request is { } request)
         {
@@ -147,8 +154,14 @@ private static dynamic HeaderTable(Dictionary<string, string[]> headers, Diction
         return headerTable;
     }
 
-    internal static void FormatAsPlainText(this HttpResponse response, FormatContext context)
+    internal static void FormatAsPlainText(this HttpResponse? response, FormatContext context)
     {
+        if (response is null)
+        {
+            context.Writer.WriteLine("null");
+            return;
+        }
+
         if (response.Request is { } request)
         {
             context.Writer.WriteLine($"Request Method: {request.Method}");