Why does socket.ack always send back an array?

[JasterV]

Hi! I realized that when I send back an ack from the server it is always in the form of an array. Is that an expected behavior? I can't find it on the official Socket.io protocol spec.

In my case I just want the server to acknowledge back a single structured piece of data but the client gets an array with that data inside instead.

I would appreciate some help :D

[JasterV]

I've noticed that you actually enforce the transformation of an Ack packet to an array on the code

socketioxide/socketioxide/src/packet.rs

Line 331 in c8bbd22

EventAck(data, _) | BinaryAck(BinaryPacket { data, .. }, _) => {

[Totodore]

It might be a miscomprehension, but according to the protocol an ack packet is always encoded as an array:
https://socket.io/docs/v4/socket-io-protocol/#acknowledgement-1

However it should be de-encoded as a single element in the frontend if you provided only one element.
It would be worth to check the encoding code for ack packet in the official implementation.