forward html and javascript requests to devserver

Author: thefringeninja

src/SqlStreamStore.HAL.DevServer/DevServerStartup.cs

@@ -1,11 +1,15 @@
 namespace SqlStreamStore.HAL.DevServer
 {
     using System;
+    using System.Linq;
+    using System.Net.Http;
+    using System.Net.Http.Headers;
     using System.Threading.Tasks;
     using Microsoft.AspNetCore.Builder;
     using Microsoft.AspNetCore.Hosting;
     using Microsoft.AspNetCore.Http;
     using Microsoft.Extensions.DependencyInjection;
+    using Microsoft.Extensions.Primitives;
     using MidFunc = System.Func<
         Microsoft.AspNetCore.Http.HttpContext,
         System.Func<System.Threading.Tasks.Task>,
@@ -15,10 +19,12 @@
     internal class DevServerStartup : IStartup
     {
         private readonly IStreamStore _streamStore;
+        private readonly HttpClient _httpClient;
 
         public DevServerStartup(IStreamStore streamStore)
         {
             _streamStore = streamStore;
+            _httpClient = new HttpClient();
         }
 
         public IServiceProvider ConfigureServices(IServiceCollection services) => services
@@ -29,6 +35,8 @@ public void Configure(IApplicationBuilder app) => app
             .UseResponseCompression()
             .Use(CatchAndDisplayErrors)
             .Use(AllowAllOrigins)
+            .Use(SqlStreamStreamBrowserJavascript)
+            .Use(SqlStreamStreamBrowserHtml)
             .UseSqlStreamStoreHal(_streamStore);
 
         private static MidFunc CatchAndDisplayErrors => async (context, next) =>
@@ -57,5 +65,49 @@ public void Configure(IApplicationBuilder app) => app
 
             return next();
         };
+
+        private static string[] GetAcceptHeaders(HttpRequest contextRequest)
+            => Array.ConvertAll(
+                contextRequest.Headers.GetCommaSeparatedValues("Accept"),
+                value => MediaTypeWithQualityHeaderValue.TryParse(value, out var header)
+                    ? header.MediaType
+                    : null);
+
+        private MidFunc SqlStreamStreamBrowserJavascript => (context, next)
+            => context.Request.Path.Value?.EndsWith(".js") ?? false
+                ? ForwardToClientDevServer(
+                    context,
+                    $"{context.Request.PathBase.ToUriComponent()}{context.Request.Path.ToUriComponent()}")
+                : next();
+
+        private MidFunc SqlStreamStreamBrowserHtml => (context, next)
+            => GetAcceptHeaders(context.Request)
+                .Any(header => header == "text/html")
+                ? ForwardToClientDevServer(context, context.Request.PathBase.ToUriComponent())
+                : next();
+
+        private async Task ForwardToClientDevServer(HttpContext context, string path)
+        {
+            using(var request = new HttpRequestMessage(
+                new HttpMethod(context.Request.Method),
+                new UriBuilder
+                {
+                    Port = 3000,
+                    Host = "localhost",
+                    Path = path,
+                    Query = context.Request.QueryString.ToUriComponent()
+                }.Uri))
+            using(var response = await _httpClient.SendAsync(request))
+            using(var stream = await response.Content.ReadAsStreamAsync())
+            {
+                context.Response.StatusCode = (int) response.StatusCode;
+                foreach(var header in response.Headers.Concat(response.Content.Headers))
+                {
+                    context.Response.Headers.Add(header.Key, new StringValues(header.Value.ToArray()));
+                }
+
+                await stream.CopyToAsync(context.Response.Body, 8192, context.RequestAborted);
+            }
+        }
     }
 }

src/SqlStreamStore.HAL/HttpContextExtensions.cs

@@ -1,12 +1,15 @@
 namespace SqlStreamStore.HAL
 {
+    using System;
     using System.IO;
     using System.Linq;
     using System.Net.Http;
+    using System.Net.Http.Headers;
     using System.Threading.Tasks;
     using Microsoft.AspNetCore.Http;
     using Newtonsoft.Json;
     using Newtonsoft.Json.Serialization;
+    using SqlStreamStore.Streams;
 
     internal static class HttpContextExtensions
     {
@@ -76,6 +79,14 @@ public static int GetExpectedVersion(this HttpRequest request)
                 request.Headers[Constants.Headers.ExpectedVersion],
                 out var expectedVersion)
                 ? expectedVersion
-                : Streams.ExpectedVersion.Any;
+                : ExpectedVersion.Any;
+
+        public static string[] GetAcceptHeaders(this HttpRequest contextRequest)
+            => Array.ConvertAll(
+                contextRequest.Headers
+                    .GetCommaSeparatedValues("Accept"),
+                value => MediaTypeWithQualityHeaderValue.TryParse(value, out var header)
+                    ? header.MediaType
+                    : null);
     }
 }

src/SqlStreamStore.HAL/SqlStreamStoreHalMiddleware.cs

@@ -2,7 +2,6 @@
 {
     using System;
     using System.Linq;
-    using System.Net.Http.Headers;
     using System.Threading.Tasks;
     using Halcyon.HAL;
     using Microsoft.AspNetCore.Builder;
@@ -27,12 +26,9 @@ private static MidFunc MethodsNotAllowed(params string[] methods) => (context, n
             return Task.CompletedTask;
         };
 
-        private static MidFunc AcceptOnlyHalJson => (context, next) =>
+        private static MidFunc AcceptHalJson => (context, next) =>
         {
-            var accept = context.Request.Headers.GetCommaSeparatedValues("Accept")
-                .Select(value => MediaTypeWithQualityHeaderValue.TryParse(value, out var header)
-                    ? header.MediaType
-                    : null);
+            var accept = context.Request.GetAcceptHeaders();
 
             return accept.Any(header => header == Constants.Headers.ContentTypes.HalJson
                                         || header == Constants.Headers.ContentTypes.Any)
@@ -72,7 +68,7 @@ public static IApplicationBuilder UseSqlStreamStoreHal(
 
             return builder
                 .Use(ExceptionHandlingMiddleware.HandleExceptions)
-                .Use(AcceptOnlyHalJson)
+                .Use(AcceptHalJson)
                 .Use(Index)
                 .Map("/stream", UseAllStream(streamStore))
                 .Map("/streams", UseStream(streamStore));