Test Framework - Don't serialize string Json element directly to session

sdk/core/Azure.Core.TestFramework/src/RecordEntry.cs

@@ -188,8 +188,11 @@ private void SerializeBody(Utf8JsonWriter jsonWriter, string name, byte[] reques
 
                     // We use array as a wrapper for string based serialization
                     // so if the root is an array we can't write it directly
-                    // fallback to generic string writing
-                    if (document.RootElement.ValueKind != JsonValueKind.Array)
+                    // fallback to generic string writing. Also, if the root is a string
+                    // we don't want to write it directly, as this would make matching
+                    // not won't work in libraries that allow passing JSON as a string.
+                    if (document.RootElement.ValueKind != JsonValueKind.Array &&
+                        document.RootElement.ValueKind != JsonValueKind.String)
                     {
                         // Make sure we can replay JSON is exactly the same as the source
                         // for the case where service response was pre-formatted

sdk/core/Azure.Core/tests/Azure.Core.Tests.csproj

@@ -34,6 +34,7 @@
     <Compile Include="..\src\Shared\RetriableStream.cs" />
     <Compile Include="..\src\Shared\RequestRequestContent.cs" />
     <Compile Include="..\src\Shared\ValueStopwatch.cs" />
+    <Compile Include="..\src\Shared\AutoRest\Utf8JsonRequestContent.cs" />
   </ItemGroup>
 
 </Project>

sdk/core/Azure.Core/tests/RecordSessionTests.cs

@@ -84,6 +84,63 @@ public void CanRoundtripSessionRecord(string body, string contentType)
             CollectionAssert.AreEqual(bodyBytes, deserializedRecord.Response.Body);
         }
 
+        [Test]
+        public void CanRoundTripEncodedJson()
+        {
+            var body = "{\\u0002json\\u0002:{\\u0002json\\u0002:\\u0002value\\u0002}}";
+            var contentType = "application/json";
+            var session = new RecordSession();
+            session.Variables["a"] = "value a";
+            session.Variables["b"] = "value b";
+            var content = new Utf8JsonRequestContent();
+            content.JsonWriter.WriteStringValue(body);
+            var request = new MockRequest()
+            {
+                Content = content
+            };
+
+            RecordEntry recordEntry = RecordTransport.CreateEntry(request, new MockResponse(200));
+            recordEntry.Request.Headers.Add("Content-Type", new[] { contentType });
+            recordEntry.Request.Headers.Add("Other-Header", new[] { "multi", "value" });
+            recordEntry.RequestUri = "url";
+            recordEntry.RequestMethod = RequestMethod.Put;
+
+            recordEntry.Response.Headers.Add("Content-Type", new[] { contentType });
+            recordEntry.Response.Headers.Add("Other-Response-Header", new[] { "multi", "value" });
+
+            session.Entries.Add(recordEntry);
+
+            var arrayBufferWriter = new ArrayBufferWriter<byte>();
+            using var jsonWriter = new Utf8JsonWriter(arrayBufferWriter, new JsonWriterOptions()
+            {
+                Indented = true
+            });
+            session.Serialize(jsonWriter);
+            jsonWriter.Flush();
+
+            TestContext.Out.WriteLine(Encoding.UTF8.GetString(arrayBufferWriter.WrittenMemory.ToArray()));
+
+            var document = JsonDocument.Parse(arrayBufferWriter.WrittenMemory);
+            var deserializedSession = RecordSession.Deserialize(document.RootElement);
+
+            Assert.AreEqual("value a", deserializedSession.Variables["a"]);
+            Assert.AreEqual("value b", deserializedSession.Variables["b"]);
+
+            RecordEntry deserializedRecord = deserializedSession.Entries.Single();
+
+            Assert.AreEqual(RequestMethod.Put, recordEntry.RequestMethod);
+            Assert.AreEqual("url", recordEntry.RequestUri);
+            Assert.AreEqual(200, recordEntry.StatusCode);
+
+            CollectionAssert.AreEqual(new[] { contentType }, deserializedRecord.Request.Headers["content-type"]);
+            CollectionAssert.AreEqual(new[] { "multi", "value" }, deserializedRecord.Request.Headers["other-header"]);
+
+            CollectionAssert.AreEqual(new[] { contentType }, deserializedRecord.Response.Headers["content-type"]);
+            CollectionAssert.AreEqual(new[] { "multi", "value" }, deserializedRecord.Response.Headers["other-response-header"]);
+
+            CollectionAssert.AreEqual(recordEntry.Request.Body, deserializedRecord.Request.Body);
+        }
+
         [Test]
         public void RecordMatcherThrowsExceptionsWithDetails()
         {