Fixing HTTP content negotiation for .NET

Author: fabiocav

src/WebJobs.Script/Binding/HttpBinding.cs

@@ -156,19 +156,20 @@ private static HttpContent CreateResultContent(object content, string mediaType)
 
         private static HttpResponseMessage CreateNegotiatedResponse(HttpRequestMessage request, HttpStatusCode statusCode, object content)
         {
+            HttpResponseMessage result = request.CreateResponse(statusCode);
+
             if (content == null)
             {
-                return request.CreateResponse(statusCode);
+                return result;
             }
 
             var configuration = request.GetConfiguration();
             IContentNegotiator negotiator = configuration.Services.GetContentNegotiator();
-            var result = negotiator.Negotiate(content.GetType(), request, configuration.Formatters);
+            var negotiationResult = negotiator.Negotiate(content.GetType(), request, configuration.Formatters);
 
-            return new HttpResponseMessage(statusCode)
-            {
-                Content = new ObjectContent(content.GetType(), content, result.Formatter, result.MediaType)
-            };
+            result.Content = new ObjectContent(content.GetType(), content, negotiationResult.Formatter, negotiationResult.MediaType);
+
+            return result;
         }
 
         public void ProcessResult(IDictionary<string, object> functionArguments, object[] systemArguments, string triggerInputName, object result)
@@ -184,8 +185,7 @@ public void ProcessResult(IDictionary<string, object> functionArguments, object[
                 HttpResponseMessage response = result as HttpResponseMessage;
                 if (response == null)
                 {
-                    response = request.CreateResponse(HttpStatusCode.OK);
-                    response.Content = new ObjectContent(result.GetType(), result, new JsonMediaTypeFormatter());
+                    response = CreateNegotiatedResponse(request, HttpStatusCode.OK, result);
                 }
 
                 request.Properties[ScriptConstants.AzureFunctionsHttpResponseKey] = response;

test/WebJobs.Script.Tests/CSharpEndToEndTests.cs

@@ -266,7 +266,8 @@ public async Task HttpTrigger_Post_Dynamic()
                 Method = HttpMethod.Post,
                 Content = new StringContent(input.ToString())
             };
-            request.SetConfiguration(new HttpConfiguration());
+            request.SetConfiguration(Fixture.RequestConfiguration);
+            request.Headers.Accept.Add(new MediaTypeWithQualityHeaderValue("text/plain"));
             request.Content.Headers.ContentType = new MediaTypeHeaderValue("application/json");
 
             Dictionary<string, object> arguments = new Dictionary<string, object>
@@ -283,6 +284,44 @@ public async Task HttpTrigger_Post_Dynamic()
             Assert.Equal("Name: Mathew Charles, Location: Seattle", body);
         }
 
+        [Theory]
+        [InlineData("application/json", "\"Name: Fabio Cavalcante, Location: Seattle\"")]
+        [InlineData("application/xml", "<string xmlns=\"http://schemas.microsoft.com/2003/10/Serialization/\">Name: Fabio Cavalcante, Location: Seattle</string>")]
+        [InlineData("text/plain", "Name: Fabio Cavalcante, Location: Seattle")]
+        public async Task HttpTrigger_GetWithAccept_NegotiatesContent(string accept, string expectedBody)
+        {
+            var input = new JObject
+            {
+                { "name", "Fabio Cavalcante" },
+                { "location", "Seattle" }
+            };
+
+            HttpRequestMessage request = new HttpRequestMessage
+            {
+                RequestUri = new Uri(string.Format("http://localhost/api/httptrigger-dynamic")),
+                Method = HttpMethod.Post,
+                Content = new StringContent(input.ToString())
+            };
+            request.SetConfiguration(Fixture.RequestConfiguration);
+            request.Headers.Accept.Add(new MediaTypeWithQualityHeaderValue(accept));
+            request.Content.Headers.ContentType = new MediaTypeHeaderValue("application/json");
+
+            Dictionary<string, object> arguments = new Dictionary<string, object>
+            {
+                { "input", request },
+                { ScriptConstants.SystemTriggerParameterName, request }
+            };
+
+            await Fixture.Host.CallAsync("HttpTrigger-Dynamic", arguments);
+
+            HttpResponseMessage response = (HttpResponseMessage)request.Properties[ScriptConstants.AzureFunctionsHttpResponseKey];
+            Assert.Equal(HttpStatusCode.OK, response.StatusCode);
+            Assert.Equal(accept, response.Content.Headers.ContentType.MediaType);
+
+            string body = await response.Content.ReadAsStringAsync();
+            Assert.Equal(expectedBody, body);
+        }
+
         public class TestFixture : EndToEndTestFixture
         {
             private const string ScriptRoot = @"TestScripts\CSharp";

test/WebJobs.Script.Tests/TestScripts/CSharp/HttpTrigger-Dynamic/run.csx

@@ -1,11 +1,4 @@
-using System;
-using System.Net;
-using System.Net.Http;
-
-public static HttpResponseMessage Run(dynamic input)
+public static string Run(dynamic input)
 {
-    return new HttpResponseMessage(HttpStatusCode.OK)
-    {
-        Content = new StringContent($"Name: {input.name}, Location: {input.location}")
-    };
+    return $"Name: {input.name}, Location: {input.location}";
 }