Insert - conflict options with a function on nested data

r.table('table').insert({
    id: id,
    session: session,
    sockets: [{
        id: socket_id
    }]
}, {conflict: function(id, oldDoc, newDoc) {
    return newDoc.merge({
        session: session,
        sockets: sockets(oldDoc('sockets'), newDoc('sockets'))
    });
}})

Adding new objects works fine:

function sockets(oldDoc, newDoc) {
    return oldDoc.append({
        id: socket_id
   });
}

Is it possible to update / remove nested data using oldDoc object?

Start with the insert conflict function and its oldDoc/newDoc expressions in the issue body, especially the nested sockets data. Determine whether oldDoc supports updating or removing nested values, then document the supported behavior and syntax; no repository file or test is named in the report.