how to delete a room in socket.io

Also, it's worth mentioning that...

Upon disconnection, sockets leave all the channels they were part of automatically, and no special teardown is needed on your part.

https://socket.io/docs/rooms-and-namespaces/ (Disconnection)

if you are using socket io v4 or greater you can use this:

io.in("room1").socketsLeave("room1");

//all the clients in room1 will leave romm1
//hence deleting the room automatically
//as there are no more active users in it

For an up-to-date answer to this question, everyone who wants to remove a room can make use of Namespace.clients(cb). The cb callback will receive an error object as the first argument (null if no error) and a list of socket IDs as the second argument.

It should work fine with socket.io v2.1.0, not sure which version is the earliest compatible one.

io.of('/').in('chat').clients((error, socketIds) => {
  if (error) throw error;

  socketIds.forEach(socketId => io.sockets.sockets[socketId].leave('chat'));

});

@See https://github.com/socketio/socket.io/issues/3042
@See https://socket.io/docs/server-api/#namespace-clients-callback

Is that what you want ?

io.sockets.clients(someRoom).forEach(function(s){
    s.leave(someRoom);
});