Issue with cadinality many and dataType binary on eventHubTrigger Azure function in nodejs

[Kiupi]

Hello,

I currently facing an issue on node azure function using eventHubTrigger with cardinality set to many and dataType to binary.
Here is my function.json file :

{
"bindings": [
    {
      "type": "eventHubTrigger",
      "name": "eventHubMessages",
      "direction": "in",
      "eventHubName": _"topic-name",_
      "connection": "EventHubConnexion",
      "cardinality": "many",
      "consumerGroup": "$Default",
      "dataType": "binary"
    }
  ],
  "scriptFile": "../dist/EventHubTrigger/index.js"
}

In fact, I set up a MirrorMaker which send datas from a kafka bus on a personal eventHub. Kafka datas are avro datas with single object encoding sent as binary buffer.

When my azure function trigger on my eventHub, I get the datas on an array but it's an array of strings and not bytes while datatype is set to binary. Moreover, when i set cardinality to one and not many, datas have good format but I don't want to use this cardinality because it is bad for performances.

I need to get this frames as bytes buffer with cardinality to many because i need to decode frames for extract all usefulls datas.

To prevent this issue I also tried to convert frames stringified thank to the Buffer.from method but it seems string convertion is wrong because when I try to decode, then i have an error while it's work with the buffer given when I set cardinality to one.

Is it a known issue, specific to nodejs, or an abnormal behavior ?

[Kiupi]

I finally find that frames were encoded in base64, which allow me to decode correctly frames.
But I still find strange to get an array of string and not buffer when we set datatype to binary.