Error concatenating multiple fields with one arcade attribute rule

Question

Quick disclaimer: I'm still learning arcade and jumping into code like this right off the bat was probably a poor idea.

I'm attempting to cut down on the waste of having three separate rules and combine them into one. The whole idea here is to get the three apn values and combine them in different formats, two text and one integer. We have attribute assistant code that does the same thing.

My main issue here is that this code works in the dev playground and validates just fine in the expression builder but wont run in pro, where I get the below error message. Any help with this?

//
// fields to concatenate
var apnparts = [$feature.BOOK, $feature.PAGE, $feature.NUMBER2DIG]
// the concantenation
var total = Concatenate(apnparts, "-")
var int = Concatenate(apnparts, "", '#')
var nodash = Concatenate(apnparts,"")

return {
    "result" : {
        "attributes" : {
            "$feature.APN_TOTAL" : total,
            "$feature.APN_INTEGER" : int,
            "$feature.APN_NODASH" : nodash
        }
    }
}

JoeBorgione · Answer

Happens to the best of us: you get to a point of diminishing returns despite your best efforts!

TravysBaker · Answer

Through my testing its every selected parcel exhibits that error and our parcels are pretty clean too, so no nulls or wonkiness here. When I removed the Integer field from the script that error affects the next field, which is No Dash in this case.

I can get all this to work separately as different rules but combining them is beyond me at this point on the learning curve.

JoeBorgione · Answer

Take a look at the parcel with the global id mentioned above:  my guess is it has a null value or something else goofy in one of the attributes you are trying to concatenate.