How to make a procedure that repairs any damaged item?

I don’t think that there is a procedure block for that. (Not 100% sure) But you can make a procedure that removes the item that you want to be repaired and then instantly adding it back into the inventory which creates the illusion of it being repaired. This does remove the enchantments unfortunately.

I ran into this very issue with my last mod update.  I created a ranged item (Bow) but realized that there is no option in the UI for what repairs the bow as it gets damaged.  Having a Repair Item(s) option where we could specify what item repairs that tool or "Ranged Item" in my case would be beneficial.  Then when the Ranged Item is placed in an anvil, with the other item to use for repairing with, would take care of it. 

Ranged Items don't have the procedure for repairs as an option in the UI, nor does it have a Repair Item(s) argument to add.  Of course having a dedicated procedure to repair any item that takes damage would be great (to start with) and customized as needed.  -Steve