arcade expression to assign address systems

address systems.js

var layerName = 'Address Systems';

var set = FeatureSetByName($datastore, layerName);

function getAttributeFromLargestArea(feat, set, field) {
    var items = intersects(set, feat);
    var counts = count(items);
    
    if (counts == 0) {
        return { 'errorMessage': 'No intersection found' };
    }
    
    if (counts == 1) {
        var result = first(items);

        return result[field];
    }

    var largest = -1;
    var result;

    for (var item in items) {
        var size = area(intersection(item, feat));

        if (size > largest) {
            largest = size;
            result = item[field];
        }
    }

    return result;
}

function getGrid(feat, set, field, offset) {
  var offset = Offset(feat, offset)
  
  return getAttributeFromLargestArea(offset, set, field);
}

var rightResult = getGrid($feature, set, 'GRID', 50);
var leftResult = getGrid($feature, set, 'GRID', -50);