What is the recommended replacement of the js option?

[tsirkin]

We were using the js together with a --preload to run geth in a private network using docker.
The main use-case was to mine blocks only when a transaction exists
(Similar to this https://ethereum.stackexchange.com/questions/3151/how-to-make-miner-to-mine-only-when-there-are-pending-transactions and this https://github.com/niksmac/ethereum-scripts/blob/master/src/mining-only-new-txs.js)
But now that the js is deprecated how can we achieve the same?
The only option we found so far, was to run console and use --preload.
Unfortunately, this requires us to also allow tty+std_open in docker which we would like to avoid.
Is there any way to do this?

[s1na]

Yes this is not possible right now. I will look into this.