Script to enforce max in token bar values

I'm looking for a script that will prevent the entry of more HP than what the max is set to be. For instance if the value|max of bar1 is 10|12 and a player (or myself?) enters "+5" the new value of bar1 will be 12. This is not only for when my players use healing of any sort, but I am planning to drop a troll on them and I'd love to have an easy way to maintain that without having to check what the max value is.

Any ideas, or is this another script I'll have to write myself?

This really simple no-frills script should do what you need:

on("change:token", function(obj) {
    const bar = 3; // change this to the number you use for the HP bar
    let maxValue = parseInt(obj.get(`bar${bar}_max`));
    let curValue = parseInt(obj.get(`bar${bar}_value`));
    if (!isNaN(maxValue) && !isNaN(curValue) && curValue > maxValue) {
        obj.set(`bar${bar}_value`,maxValue);
    }
});

And if you just want to constrain all 3 bars to max, if they have one:

on("change:token", function(obj) {
    for(let i = 1; i <= 3; i++) {
        let maxValue = parseInt(obj.get(`bar${i}_max`));
        let curValue = parseInt(obj.get(`bar${i}_value`));
        if (!isNaN(maxValue) && !isNaN(curValue) && curValue > maxValue) {
            obj.set(`bar${i}_value`,maxValue);
        }    
    }
});