feat: first support of bindings for kafka key

Close #67

index.js

@@ -7,6 +7,19 @@ module.exports.parse = async ({ message, defaultSchemaFormat }) => {
   message['x-parser-original-payload'] = message.payload;
   message.payload = transformed;
   delete message.schemaFormat;
+
+  async function handleProtocolKey() {
+    for (const protocol of Object.keys(message.bindings)) {
+      var key = message.bindings[protocol].key;
+      if (key) {
+        const bindingsTransformed = await avroToJsonSchema(key);
+        message[`x-parser-original-bindings-${protocol}-key`] = key;
+        message.bindings[protocol].key = bindingsTransformed;
+      }
+    }
+  }
+
+  await handleProtocolKey();
 };
 
 module.exports.getMimeTypes = () => {

tests/asyncapi-avro-1.9.0-bindings.yaml

@@ -0,0 +1,19 @@
+asyncapi: 2.0.0
+info:
+  title: My API
+  version: '1.0.0'
+channels:
+  mychannel:
+    publish:
+      message:
+        schemaFormat: application/vnd.apache.avro;version=1.9.0
+        payload:
+          $ref: 'schemas/Person-1.9.0-namespace.avsc'
+        bindings:
+          kafka:
+            key:
+              $ref: 'schemas/Person-1.9.0-namespace.avsc'
+          mqtt:
+            x-test:
+              type: string
+