Understanding reactions about observer-util HOT 1 CLOSED

If you use a property inside a reaction in any JS way and change it later in any way JS the reaction will re-run. console.log is an edge case that runs none JS code internally (it iterates all properties but not with interceptible JS code). Try to change console.log("b-", counter) to console.log("b-", JSON.stringify(counter)) and see what happens. JSON.stringify runs standard JS code internally which results in reaction re-runs on property changes. This behavior is something that I don't intend to change and it is pretty much related to console.log only. Other built-in methods and intercepted. I hope this helps.

from observer-util.