Update increment is not possible via update()

[fulopattila122]

I'm trying to run the following query:

 var newData = {stock: 'stock + 1'};
 db.where({id: data.id}).update('products', newData, ...

The generated sql is

UPDATE `products` SET `stock`='stock+1' WHERE `id`=1

which - due to the single quotation around stock+1 - will result in a 0 stock value.
As a workaround I can still run the query directly, however it'd be nice to have this to work.