const collName = "foo";
const coll = db[collName];
// Can do single-document update with sort.
{
    coll.drop();
    coll.insertMany([{ a: 1 }, { a: 2 }]);
    db.runCommand({
        update: collName,
        updates: [{ q: {}, u: { $inc: { a: 1 } }, multi: false, sort: { a: -1 } }]
    });
    assert(coll.findOne({ a: 3 }))
}

// Cannot do single-document delete with sort?
{
    coll.drop();
    coll.insertMany([{ a: 1 }, { a: 2 }]);
    db.runCommand({
        delete: collName,
        deletes: [{ q: {}, limit: 1, sort: { a: -1 } }]
    });
    // Throws: MongoServerError: BSON field 'delete.deletes.sort' is an unknown field.
}