onEach on them.
await reddinx.localUpdate(subredditName[, options])
By default, the onEach hook is only called on records when saved on disk
(either during an initial or incremental import). If you want to call it on
old records as well that are outside of the incrementalWindow, you should use
reddinx.localUpdate.
This will get through the list of all records already saved on disk, apply your
custom onEach hook on them and update the result on disk. If onEach returns
false, the existing record file will be deleted.