From e6ecf5cc84ed3c0e74d759b527f3a184cf71efb1 Mon Sep 17 00:00:00 2001
From: Stef Heyenrath <Stef.Heyenrath@gmail.com>
Date: Thu, 23 Aug 2018 12:30:36 +0000
Subject: [PATCH] ResponseMessageTransformer (#190 ; #188)

ResponseMessageTransformer (#190 ; #188)
---
 .../ResponseMessageTransformer.cs             | 25 +++++++++++--------
 .../RequestMessageBodyMatcherTests.cs         |  3 +--
 .../ResponseWithHandlebarsTests.cs            | 23 +++++++++++++++++
 3 files changed, 39 insertions(+), 12 deletions(-)

diff --git a/src/WireMock.Net/Transformers/ResponseMessageTransformer.cs b/src/WireMock.Net/Transformers/ResponseMessageTransformer.cs
index 36de18bff..586219dda 100644
--- a/src/WireMock.Net/Transformers/ResponseMessageTransformer.cs
+++ b/src/WireMock.Net/Transformers/ResponseMessageTransformer.cs
@@ -1,4 +1,5 @@
-using System.Collections.Generic;
+using System;
+using System.Collections.Generic;
 using System.Linq;
 using HandlebarsDotNet;
 using Newtonsoft.Json;
@@ -55,37 +56,41 @@ public static ResponseMessage Transform(RequestMessage requestMessage, ResponseM
 
         private static void TransformBodyAsJson(object template, ResponseMessage original, ResponseMessage responseMessage)
         {
-            JObject jobject;
+            JToken jToken;
             switch (original.BodyAsJson)
             {
                 case JObject bodyAsJObject:
-                    jobject = bodyAsJObject;
+                    jToken = bodyAsJObject;
+                    break;
+
+                case Array bodyAsArray:
+                    jToken = JArray.FromObject(bodyAsArray);
                     break;
 
                 default:
-                    jobject = JObject.FromObject(original.BodyAsJson);
+                    jToken = JObject.FromObject(original.BodyAsJson);
                     break;
             }
 
-            WalkNode(jobject, template);
+            WalkNode(jToken, template);
 
-            responseMessage.BodyAsJson = jobject;
+            responseMessage.BodyAsJson = jToken;
         }
 
         private static void WalkNode(JToken node, object template)
         {
             if (node.Type == JTokenType.Object)
             {
-                // In case of Object, loop all children.
-                foreach (JProperty child in node.Children<JProperty>())
+                // In case of Object, loop all children. Do a ToArray() to avoid `Collection was modified` exceptions.
+                foreach (JProperty child in node.Children<JProperty>().ToArray())
                 {
                     WalkNode(child.Value, template);
                 }
             }
             else if (node.Type == JTokenType.Array)
             {
-                // In case of Array, loop all items.
-                foreach (JToken child in node.Children())
+                // In case of Array, loop all items. Do a ToArray() to avoid `Collection was modified` exceptions.
+                foreach (JToken child in node.Children().ToArray())
                 {
                     WalkNode(child, template);
                 }
diff --git a/test/WireMock.Net.Tests/RequestMatchers/RequestMessageBodyMatcherTests.cs b/test/WireMock.Net.Tests/RequestMatchers/RequestMessageBodyMatcherTests.cs
index d5cd891ee..2516b68d0 100644
--- a/test/WireMock.Net.Tests/RequestMatchers/RequestMessageBodyMatcherTests.cs
+++ b/test/WireMock.Net.Tests/RequestMatchers/RequestMessageBodyMatcherTests.cs
@@ -1,5 +1,4 @@
-using System;
-using Moq;
+using Moq;
 using NFluent;
 using WireMock.Matchers;
 using WireMock.Matchers.Request;
diff --git a/test/WireMock.Net.Tests/ResponseBuilderTests/ResponseWithHandlebarsTests.cs b/test/WireMock.Net.Tests/ResponseBuilderTests/ResponseWithHandlebarsTests.cs
index c8aa60bdf..98497e628 100644
--- a/test/WireMock.Net.Tests/ResponseBuilderTests/ResponseWithHandlebarsTests.cs
+++ b/test/WireMock.Net.Tests/ResponseBuilderTests/ResponseWithHandlebarsTests.cs
@@ -493,5 +493,28 @@ public void Response_ProvideResponse_Handlebars_JsonPath_SelectTokens_Throws()
             // Act
             Check.ThatAsyncCode(() => response.ProvideResponseAsync(request)).Throws<ArgumentNullException>();
         }
+
+        [Fact]
+        public async Task Response_ProvideResponse_Handlebars_WithBodyAsJson_ResultAsArray()
+        {
+            // Assign
+            string jsonString = "{ \"a\": \"test 1\", \"b\": \"test 2\" }";
+            var bodyData = new BodyData
+            {
+                BodyAsJson = JsonConvert.DeserializeObject(jsonString),
+                Encoding = Encoding.UTF8
+            };
+            var request = new RequestMessage(new UrlDetails("http://localhost/foo_array"), "POST", ClientIp, bodyData);
+
+            var response = Response.Create()
+                .WithBodyAsJson(new[] { "first", "{{request.path}}", "{{request.bodyAsJson.a}}", "{{request.bodyAsJson.b}}", "last" })
+                .WithTransformer();
+
+            // Act
+            var responseMessage = await response.ProvideResponseAsync(request);
+
+            // Assert
+            Check.That(JsonConvert.SerializeObject(responseMessage.BodyAsJson)).Equals("[\"first\",\"/foo_array\",\"test 1\",\"test 2\",\"last\"]");
+        }
     }
 }
\ No newline at end of file