Fix issues with Proxy mode and Binary Request Bodies

src/WireMock.Net/Matchers/Request/RequestMessageBodyMatcher.cs

@@ -145,17 +145,17 @@ private double CalculateMatchScore(RequestMessage requestMessage)
 
             if (Func != null)
             {
-                return MatchScores.ToScore(requestMessage?.BodyData?.DetectedBodyType == BodyType.String && Func(requestMessage.BodyData.BodyAsString));
+                return MatchScores.ToScore(Func(requestMessage?.BodyData?.BodyAsString));
             }
 
             if (JsonFunc != null)
             {
-                return MatchScores.ToScore(requestMessage?.BodyData?.DetectedBodyType == BodyType.Json && JsonFunc(requestMessage.BodyData.BodyAsJson));
+                return MatchScores.ToScore(JsonFunc(requestMessage?.BodyData?.BodyAsJson));
             }
 
             if (DataFunc != null)
             {
-                return MatchScores.ToScore(requestMessage?.BodyData?.DetectedBodyType == BodyType.Bytes && DataFunc(requestMessage.BodyData.BodyAsBytes));
+                return MatchScores.ToScore(DataFunc(requestMessage?.BodyData?.BodyAsBytes));
             }
 
             return MatchScores.Mismatch;

src/WireMock.Net/Util/BodyParser.cs

@@ -13,8 +13,8 @@ namespace WireMock.Util
 {
     internal static class BodyParser
     {
-        private static readonly Encoding DefaultEncoding = Encoding.UTF8;
-        private static readonly Encoding[] SupportedBodyAsStringEncodingForMultipart = { Encoding.UTF8, Encoding.ASCII };
+        private static readonly Encoding DefaultEncoding = new UTF8Encoding(encoderShouldEmitUTF8Identifier: false, throwOnInvalidBytes: true);
+        private static readonly Encoding[] SupportedBodyAsStringEncodingForMultipart = { DefaultEncoding, Encoding.ASCII };
 
         /*
             HEAD - No defined body semantics.

test/WireMock.Net.Tests/FluentMockServerTests.Proxy.cs

@@ -6,6 +6,7 @@
 using System.Net.Http.Headers;
 using System.Text;
 using System.Threading.Tasks;
+using FluentAssertions;
 using WireMock.Matchers.Request;
 using WireMock.RequestBuilders;
 using WireMock.ResponseBuilders;
@@ -308,6 +309,43 @@ public async Task FluentMockServer_Proxy_Should_preserve_cookie_header_in_proxie
             Check.That(receivedRequest.Cookies).ContainsPair("name", "value");
         }
 
+        /// <summary>
+        /// Send some binary content in a request through the proxy and check that the same content
+        /// arrived at the target. As example a JPEG/JIFF header is used, which is not representable
+        /// in UTF8 and breaks if it is not treated as binary content. 
+        /// </summary>
+        [Fact]
+        public async Task FluentMockServer_Proxy_Should_preserve_binary_request_content()
+        {
+            // arrange
+            var jpegHeader = new byte[] {0xFF, 0xD8, 0xFF, 0xE0, 0x00, 0x10, 0x4A, 0x46, 0x49, 0x46, 0x00};
+            var brokenJpegHeader = new byte[]
+                {0xEF, 0xBF, 0xBD, 0xEF, 0xBF, 0xBD, 0xEF, 0xBF, 0xBD, 0xEF, 0xBF, 0xBD, 0x00, 0x10, 0x4A, 0x46, 0x49, 0x46, 0x00};
+
+            bool HasCorrectHeader(byte[] bytes) => bytes.SequenceEqual(jpegHeader);
+            bool HasBrokenHeader(byte[] bytes) => bytes.SequenceEqual(brokenJpegHeader);
+
+            var serverForProxyForwarding = FluentMockServer.Start();
+            serverForProxyForwarding
+                .Given(Request.Create().WithBody(HasCorrectHeader))
+                .RespondWith(Response.Create().WithSuccess());
+
+            serverForProxyForwarding
+                .Given(Request.Create().WithBody(HasBrokenHeader))
+                .RespondWith(Response.Create().WithStatusCode(HttpStatusCode.InternalServerError));
+
+            var server = FluentMockServer.Start();
+            server
+                .Given(Request.Create())
+                .RespondWith(Response.Create().WithProxy(serverForProxyForwarding.Urls[0]));
+
+            // act
+            var response = await new HttpClient().PostAsync(server.Urls[0], new ByteArrayContent(jpegHeader));
+
+            // assert
+            Check.That(response.StatusCode).IsEqualTo(HttpStatusCode.OK);
+        }
+
         [Fact]
         public async Task FluentMockServer_Proxy_Should_set_BodyAsJson_in_proxied_response()
         {

test/WireMock.Net.Tests/FluentMockServerTests.cs

@@ -187,7 +187,7 @@ public async Task FluentMockServer_Should_exclude_body_for_methods_where_body_is
             var server = FluentMockServer.Start();
 
             server
-                .Given(Request.Create().WithBody(b => true))
+                .Given(Request.Create().WithBody((byte[] bodyBytes) =>  bodyBytes != null))
                 .AtPriority(0)
                 .RespondWith(Response.Create().WithStatusCode(400));
             server

test/WireMock.Net.Tests/RequestMatchers/RequestMessageBodyMatcherTests.cs

@@ -1,5 +1,10 @@
-using System.Linq;
+using System;
+using System.IO;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
 using Moq;
+using Newtonsoft.Json;
 using NFluent;
 using WireMock.Matchers;
 using WireMock.Matchers.Request;
@@ -208,5 +213,74 @@ public void RequestMessageBodyMatcher_GetMatchingScore_BodyAsBytes_IObjectMatche
             // Verify
             objectMatcherMock.Verify(m => m.IsMatch(It.IsAny<byte[]>()), Times.Once);
         }
+
+        [Theory]
+        [MemberData(nameof(MatchingScoreData))]
+        public async Task RequestMessageBodyMatcher_GetMatchingScore_Funcs_Matching(object body, RequestMessageBodyMatcher matcher, bool shouldMatch)
+        {
+            // assign
+            BodyData bodyData;
+            if (body is byte[] b)
+                bodyData = await BodyParser.Parse(new MemoryStream(b), null);
+            else if (body is string s)
+                bodyData = await BodyParser.Parse(new MemoryStream(Encoding.UTF8.GetBytes(s)), null);
+            else
+                throw new Exception();
+
+            var requestMessage = new RequestMessage(new UrlDetails("http://localhost"), "GET", "127.0.0.1", bodyData);
+
+            // act
+            var result = new RequestMatchResult();
+            var score = matcher.GetMatchingScore(requestMessage, result);
+
+            // assert
+            Check.That(score).IsEqualTo(shouldMatch ? 1d : 0d);
+        }
+
+        public static TheoryData<object, RequestMessageBodyMatcher, bool> MatchingScoreData
+        {
+            get
+            {
+                var json = "{'a':'b'}";
+                var str = "HelloWorld";
+                var bytes = new byte[] {0xFF, 0xD8, 0xFF, 0xE0, 0x00, 0x10, 0x4A, 0x46, 0x49, 0x46, 0x00}; 
+
+                return new TheoryData<object, RequestMessageBodyMatcher, bool>
+                {
+                    // JSON match +++
+                    {json, new RequestMessageBodyMatcher((object o) => ((dynamic) o).a == "b"), true},
+                    {json, new RequestMessageBodyMatcher((string s) => s == json), true},
+                    {json, new RequestMessageBodyMatcher((byte[] b) => b.SequenceEqual(Encoding.UTF8.GetBytes(json))), true},
+
+                    // JSON no match ---
+                    {json, new RequestMessageBodyMatcher((object o) => false), false},
+                    {json, new RequestMessageBodyMatcher((string s) => false), false},
+                    {json, new RequestMessageBodyMatcher((byte[] b) => false), false},
+                    {json, new RequestMessageBodyMatcher(), false },
+
+                    // string match +++
+                    {str, new RequestMessageBodyMatcher((object o) => o == null), true},
+                    {str, new RequestMessageBodyMatcher((string s) => s == str), true},
+                    {str, new RequestMessageBodyMatcher((byte[] b) => b.SequenceEqual(Encoding.UTF8.GetBytes(str))), true},
+
+                    // string no match ---
+                    {str, new RequestMessageBodyMatcher((object o) => false), false},
+                    {str, new RequestMessageBodyMatcher((string s) => false), false},
+                    {str, new RequestMessageBodyMatcher((byte[] b) => false), false},
+                    {str, new RequestMessageBodyMatcher(), false },
+
+                    // binary match +++
+                    {bytes, new RequestMessageBodyMatcher((object o) => o == null), true},
+                    {bytes, new RequestMessageBodyMatcher((string s) => s == null), true},
+                    {bytes, new RequestMessageBodyMatcher((byte[] b) => b.SequenceEqual(bytes)), true},
+
+                    // binary no match ---
+                    {bytes, new RequestMessageBodyMatcher((object o) => false), false},
+                    {bytes, new RequestMessageBodyMatcher((string s) => false), false},
+                    {bytes, new RequestMessageBodyMatcher((byte[] b) => false), false},
+                    {bytes, new RequestMessageBodyMatcher(), false },
+                };
+            }
+        }
     }
 }

test/WireMock.Net.Tests/Util/BodyParserTests.cs

@@ -50,6 +50,22 @@ public async Task BodyParser_Parse_ContentTypeString(string contentType, string
             Check.That(body.DetectedBodyTypeFromContentType).IsEqualTo(detectedBodyTypeFromContentType);
         }
 
+        [Theory]
+        [InlineData(new byte[] {34, 97, 34}, BodyType.Json)]
+        [InlineData(new byte[] {97}, BodyType.String)]
+        [InlineData(new byte[] {0xFF, 0xD8, 0xFF, 0xE0}, BodyType.Bytes)]
+        public async Task BodyParser_Parse_DetectedBodyType(byte[] content, BodyType detectedBodyType)
+        {
+            // arrange
+            var memoryStream = new MemoryStream(content);
+
+            // act
+            var body = await BodyParser.Parse(memoryStream, null);
+
+            // assert
+            Check.That(body.DetectedBodyType).IsEqualTo(detectedBodyType);
+        }
+
         [Fact]
         public async Task BodyParser_Parse_WithUTF8EncodingAndContentTypeMultipart_DetectedBodyTypeEqualsString()
         {