test to show returning 304 works (#450)

src/Ocelot/Headers/Middleware/HttpHeadersTransformationMiddleware.cs

@@ -38,6 +38,11 @@ namespace Ocelot.Headers.Middleware
 
             await _next.Invoke(context);
 
+            if(context.IsError)
+            {
+                return;
+            }
+
             var postFAndRs = context.DownstreamReRoute.DownstreamHeadersFindAndReplace;
 
             _postReplacer.Replace(context.DownstreamResponse, postFAndRs, context.DownstreamRequest);

test/Ocelot.AcceptanceTests/ResponseCodeTests.cs

@@ -0,0 +1,84 @@
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Net;
+using Microsoft.AspNetCore.Builder;
+using Microsoft.AspNetCore.Hosting;
+using Microsoft.AspNetCore.Http;
+using Ocelot.Configuration.File;
+using Shouldly;
+using TestStack.BDDfy;
+using Xunit;
+
+namespace Ocelot.AcceptanceTests
+{
+    public class ResponseCodeTests : IDisposable
+    {
+        private IWebHost _builder;
+        private readonly Steps _steps;
+        private string _downstreamPath;
+
+        public ResponseCodeTests()
+        {
+            _steps = new Steps();
+        }
+
+        [Fact]
+        public void should_return_response_304_when_service_returns_304()
+        {
+            var configuration = new FileConfiguration
+            {
+                ReRoutes = new List<FileReRoute>
+                    {
+                        new FileReRoute
+                        {
+                            DownstreamPathTemplate = "/{everything}",
+                            DownstreamScheme = "http",
+                            DownstreamHostAndPorts = new List<FileHostAndPort>
+                            {
+                                new FileHostAndPort
+                                {
+                                    Host = "localhost",
+                                    Port = 51879,
+                                }
+                            },
+                            UpstreamPathTemplate = "/{everything}",
+                            UpstreamHttpMethod = new List<string> { "Get" },
+                        }
+                    }
+            };
+
+            this.Given(x => x.GivenThereIsAServiceRunningOn("http://localhost:51879", "/inline.132.bundle.js", 304))
+                .And(x => _steps.GivenThereIsAConfiguration(configuration))
+                .And(x => _steps.GivenOcelotIsRunning())
+                .When(x => _steps.WhenIGetUrlOnTheApiGateway("/inline.132.bundle.js"))
+                .Then(x => _steps.ThenTheStatusCodeShouldBe(HttpStatusCode.NotModified))
+                .BDDfy();
+        }
+
+        private void GivenThereIsAServiceRunningOn(string baseUrl, string basePath, int statusCode)
+        {
+            _builder = new WebHostBuilder()
+                .UseUrls(baseUrl)
+                .UseKestrel()
+                .UseContentRoot(Directory.GetCurrentDirectory())
+                .UseIISIntegration()
+                .Configure(app =>
+                {
+                    app.UsePathBase(basePath);
+                    app.Run(async context =>
+                    {   
+                            context.Response.StatusCode = statusCode;
+                    });
+                })
+                .Build();
+
+            _builder.Start();
+        }
+        public void Dispose()
+        {
+            _builder?.Dispose();
+            _steps.Dispose();
+        }
+    }
+}

test/Ocelot.ManualTest/ocelot.json

@@ -15,6 +15,22 @@
         "TimeoutValue": 360000
       }
     },
+    {
+      "DownstreamPathTemplate": "/api/v1/todo/",
+      "DownstreamScheme": "http",
+      "UpstreamPathTemplate": "/api/v1/todo/",
+      "UpstreamHttpMethod": [ "Get", "Post" ],
+      "DownstreamHostAndPorts": [
+        {
+          "Host": "lxtodo.azurewebsites.net",
+          "Port": 80
+        }
+    
+      ],
+      "DownstreamHeaderTransform": {
+        "Location": "{DownstreamBaseUrl}, {BaseUrl}"
+      }
+    },
     {
       "DownstreamPathTemplate": "/api/values",
       "DownstreamScheme": "https",