Eliminate the NodeHostingModel enum because it isn't extensible. Instead, use extension methods on NodeServicesOptions to configure a NodeInstanceFactory.

src/Microsoft.AspNetCore.NodeServices/HostingModels/HttpNodeInstance.cs

@@ -1,12 +1,10 @@
 using System;
-using System.Collections.Generic;
 using System.IO;
 using System.Net.Http;
 using System.Text;
 using System.Text.RegularExpressions;
 using System.Threading;
 using System.Threading.Tasks;
-using Microsoft.Extensions.Logging;
 using Newtonsoft.Json;
 using Newtonsoft.Json.Serialization;
 
@@ -36,21 +34,19 @@ namespace Microsoft.AspNetCore.NodeServices.HostingModels
         private bool _disposed;
         private int _portNumber;
 
-        public HttpNodeInstance(string projectPath, string[] watchFileExtensions, ILogger nodeInstanceOutputLogger,
-            IDictionary<string, string> environmentVars, int invocationTimeoutMilliseconds, bool launchWithDebugging,
-            int debuggingPort, int port = 0)
+        public HttpNodeInstance(NodeServicesOptions options, int port = 0)
         : base(
                 EmbeddedResourceReader.Read(
                     typeof(HttpNodeInstance),
                     "/Content/Node/entrypoint-http.js"),
-                projectPath,
-                watchFileExtensions,
+                options.ProjectPath,
+                options.WatchFileExtensions,
                 MakeCommandLineOptions(port),
-                nodeInstanceOutputLogger,
-                environmentVars,
-                invocationTimeoutMilliseconds,
-                launchWithDebugging,
-                debuggingPort)
+                options.NodeInstanceOutputLogger,
+                options.EnvironmentVariables,
+                options.InvocationTimeoutMilliseconds,
+                options.LaunchWithDebugging,
+                options.DebuggingPort)
         {
             _client = new HttpClient();
         }

src/Microsoft.AspNetCore.NodeServices/HostingModels/NodeServicesOptionsExtensions.cs

@@ -0,0 +1,30 @@
+using System;
+
+namespace Microsoft.AspNetCore.NodeServices.HostingModels
+{
+    /// <summary>
+    /// Extension methods that help with populating a <see cref="NodeServicesOptions"/> object.
+    /// </summary>
+    public static class NodeServicesOptionsExtensions
+    {
+        /// <summary>
+        /// Configures the <see cref="INodeServices"/> service so that it will use out-of-process
+        /// Node.js instances and perform RPC calls over HTTP.
+        /// </summary>
+        public static void UseHttpHosting(this NodeServicesOptions options)
+        {
+            options.NodeInstanceFactory = () => new HttpNodeInstance(options);
+        }
+
+        /// <summary>
+        /// Configures the <see cref="INodeServices"/> service so that it will use out-of-process
+        /// Node.js instances and perform RPC calls over binary sockets (on Windows, this is
+        /// implemented as named pipes; on other platforms it uses domain sockets).
+        /// </summary>
+        public static void UseSocketHosting(this NodeServicesOptions options)
+        {
+            var pipeName = "pni-" + Guid.NewGuid().ToString("D"); // Arbitrary non-clashing string
+            options.NodeInstanceFactory = () => new SocketNodeInstance(options, pipeName);
+        }
+    }
+}

src/Microsoft.AspNetCore.NodeServices/HostingModels/SocketNodeInstance.cs

@@ -42,21 +42,19 @@ namespace Microsoft.AspNetCore.NodeServices.HostingModels
         private string _socketAddress;
         private VirtualConnectionClient _virtualConnectionClient;
 
-        public SocketNodeInstance(string projectPath, string[] watchFileExtensions, string socketAddress,
-            ILogger nodeInstanceOutputLogger, IDictionary<string, string> environmentVars,
-            int invocationTimeoutMilliseconds, bool launchWithDebugging, int debuggingPort)
+        public SocketNodeInstance(NodeServicesOptions options, string socketAddress)
         : base(
                 EmbeddedResourceReader.Read(
                     typeof(SocketNodeInstance),
                     "/Content/Node/entrypoint-socket.js"),
-                projectPath,
-                watchFileExtensions,
+                options.ProjectPath,
+                options.WatchFileExtensions,
                 MakeNewCommandLineOptions(socketAddress),
-                nodeInstanceOutputLogger,
-                environmentVars,
-                invocationTimeoutMilliseconds,
-                launchWithDebugging,
-                debuggingPort)
+                options.NodeInstanceOutputLogger,
+                options.EnvironmentVariables,
+                options.InvocationTimeoutMilliseconds,
+                options.LaunchWithDebugging,
+                options.DebuggingPort)
         {
             _socketAddress = socketAddress;
         }