Support Dynamic response files using Handlebars templating (#271)

* Dynamic response files using Handlebars templating
(#270)

* * Response templating / transformation using Handlebars and extensions

Directory.Build.props

@@ -4,7 +4,7 @@
   </PropertyGroup>
 
   <PropertyGroup>
-    <VersionPrefix>1.0.14</VersionPrefix>
+    <VersionPrefix>1.0.15</VersionPrefix>
   </PropertyGroup>
 
   <Choose>

README.md

@@ -8,7 +8,7 @@ A C# .NET version based on [mock4net](https://github.com/alexvictoor/mock4net) w
 * Record/playback of stubs (proxying)
 * Per-request conditional proxying
 * Stateful behaviour simulation
-* Response transformation
+* Response templating / transformation using Handlebars and extensions
 
 ## Info
 | | |

src/WireMock.Net/ResponseBuilders/Response.cs

@@ -224,7 +224,7 @@ namespace WireMock.ResponseBuilders
                 BodyAsFileIsCached = cache
             };
 
-            if (cache)
+            if (cache && !UseTransformer)
             {
                 ResponseMessage.BodyData.DetectedBodyType = BodyType.Bytes;
                 ResponseMessage.BodyData.BodyAsBytes = _fileSystemHandler.ReadResponseBodyAsFile(filename);

src/WireMock.Net/Server/FluentMockServer.Admin.cs

@@ -722,6 +722,11 @@ namespace WireMock.Server
                 responseBuilder = responseBuilder.WithDelay(responseModel.Delay.Value);
             }
 
+            if (responseModel.UseTransformer)
+            {
+                responseBuilder = responseBuilder.WithTransformer();
+            }
+
             if (!string.IsNullOrEmpty(responseModel.ProxyUrl))
             {
                 if (string.IsNullOrEmpty(responseModel.X509Certificate2ThumbprintOrSubjectName))
@@ -778,11 +783,6 @@ namespace WireMock.Server
                 responseBuilder = responseBuilder.WithBodyFromFile(responseModel.BodyAsFile);
             }
 
-            if (responseModel.UseTransformer)
-            {
-                responseBuilder = responseBuilder.WithTransformer();
-            }
-
             return responseBuilder;
         }
 

src/WireMock.Net/Transformers/ResponseMessageTransformer.cs

@@ -1,9 +1,9 @@
-using System;
+using HandlebarsDotNet;
-using System.Collections.Generic;
-using System.Linq;
-using HandlebarsDotNet;
 using Newtonsoft.Json;
 using Newtonsoft.Json.Linq;
+using System;
+using System.Collections.Generic;
+using System.Linq;
 using WireMock.Util;
 
 namespace WireMock.Transformers
@@ -24,23 +24,24 @@ namespace WireMock.Transformers
 
         public static ResponseMessage Transform(RequestMessage requestMessage, ResponseMessage original)
         {
-            bool bodyIsJson = original.BodyData.DetectedBodyType == BodyType.Json;
             var responseMessage = new ResponseMessage { StatusCode = original.StatusCode };
 
-            if (!bodyIsJson)
-            {
-                responseMessage.BodyOriginal = original.BodyData.BodyAsString;
-            }
-
             var template = new { request = requestMessage };
 
-            if (!bodyIsJson)
+            switch (original.BodyData.DetectedBodyType)
             {
-                TransformBodyAsString(template, original, responseMessage);
+                case BodyType.Json:
-            }
+                    TransformBodyAsJson(template, original, responseMessage);
-            else
+                    break;
-            {
+
-                TransformBodyAsJson(template, original, responseMessage);
+                case BodyType.File:
+                    TransformBodyAsFile(template, original, responseMessage);
+                    break;
+
+                case BodyType.String:
+                    responseMessage.BodyOriginal = original.BodyData.BodyAsString;
+                    TransformBodyAsString(template, original, responseMessage);
+                    break;
             }
 
             // Headers
@@ -150,13 +151,25 @@ namespace WireMock.Transformers
 
         private static void TransformBodyAsString(object template, ResponseMessage original, ResponseMessage responseMessage)
         {
-            var templateBody = HandlebarsContext.Compile(original.BodyData.BodyAsString);
+            var templateBodyAsString = HandlebarsContext.Compile(original.BodyData.BodyAsString);
 
             responseMessage.BodyData = new BodyData
             {
                 DetectedBodyType = original.BodyData.DetectedBodyType,
                 DetectedBodyTypeFromContentType = original.BodyData.DetectedBodyTypeFromContentType,
-                BodyAsString = templateBody(template)
+                BodyAsString = templateBodyAsString(template)
+            };
+        }
+
+        private static void TransformBodyAsFile(object template, ResponseMessage original, ResponseMessage responseMessage)
+        {
+            var templateBodyAsFile = HandlebarsContext.Compile(original.BodyData.BodyAsFile);
+
+            responseMessage.BodyData = new BodyData
+            {
+                DetectedBodyType = original.BodyData.DetectedBodyType,
+                DetectedBodyTypeFromContentType = original.BodyData.DetectedBodyTypeFromContentType,
+                BodyAsFile = templateBodyAsFile(template)
             };
         }
     }

test/WireMock.Net.Tests/ResponseBuilders/ResponseWithHandlebarsTests.cs

@@ -214,5 +214,22 @@ namespace WireMock.Net.Tests.ResponseBuilders
             // Assert
             Check.That(JsonConvert.SerializeObject(responseMessage.BodyData.BodyAsJson)).Equals("[\"first\",\"/foo_array\",\"test 1\",\"test 2\",\"last\"]");
         }
+
+        [Fact]
+        public async Task Response_ProvideResponse_Handlebars_WithBodyAsFile()
+        {
+            // Assign
+            var request = new RequestMessage(new UrlDetails("http://localhost/foo?MyUniqueNumber=1"), "GET", ClientIp);
+
+            var response = Response.Create()
+                .WithTransformer()
+                .WithBodyFromFile(@"c:\\{{request.query.MyUniqueNumber}}\test.xml"); // why use a \\ here ?
+
+            // Act
+            var responseMessage = await response.ProvideResponseAsync(request);
+
+            // Assert
+            Check.That(responseMessage.BodyData.BodyAsFile).Equals(@"c:\1\test.xml");
+        }
     }
 }