transform map script is not working

Not applicable

HI all , 

 

 

For the single user it is goving correct answer but for the multiple users it is giving undefined answer

 

Can anyone correct this script :

 

source.u_owner_name:- multiple user id is coming ,

 

  return: undefined output is coming 

 

// Transform Map Script (Single reference field: return the first matched user sys_id)
answer = (function transformEntry(source) {
   var owners = source.u_owner_name;
   var userIds = [];
       var arr = owners.split(',');
    gs.log('TM Owners tokens=' + arr.length);
 

    for (var i = 0; i < arr.length; i++) {
        var userVal = (arr[i] || '').trim();
        if (!userVal) continue;
 

        var userGR = new GlideRecord('sys_user');
        userGR.addQuery('user_name', userVal);
        userGR.query();
 

        while (userGR.next()) {
         userIds.push(userGR.name);
         
          gs.log('test_123'+userIds);
            return userIds.join(',')  ;
        }
    }

    })(source);