mapJSONConvenience and mapBufferKeyToString do not work dues to faulty isBuffer check

[tw00]

Hi! 👋

Firstly, thanks for your work on this project! 🙂

Today I used patch-package to patch kafka-streams@5.0.0 for the project I'm working on.

Here is the diff that solved my problem:

diff --git a/node_modules/kafka-streams/lib/dsl/StreamDSL.js b/node_modules/kafka-streams/lib/dsl/StreamDSL.js
index 730c871..94a2dd0 100644
--- a/node_modules/kafka-streams/lib/dsl/StreamDSL.js
+++ b/node_modules/kafka-streams/lib/dsl/StreamDSL.js
@@ -475,7 +475,7 @@ class StreamDSL {
                 return object;
             }
 
-            if (Buffer.isBuffer(object.key)) {
+            if (!Buffer.isBuffer(object.key)) {
                 return object;
             }
 

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