Assignee is Always Null

[Andrew Zibuda]

I am trying to write a script to update all child assignee's when an Epic or Story assignee is updated. The problem I am running into is I want to update assignee only when it is the same as what the old assignee was, or it is unassigned. However, when it is unassigned and I try to take displayName value of it to compare to old assignee, I get nullPointerException. So I tried to add

 if(issue.fields.assignee == null)

Before accessing displayName, but then none of the issues got through, even those WITH assignees on them. I then tried printing the issue.fields.assignee and it turns out even if there is an assignee and the sub-fields are populated it is still seen as null. Lastly, I tried to encompass it in a try-catch block, but then it throws the exception every time. If I only try to update fields that HAVE an assignee, it works without exceptions or anything. Below is the full code for the section...any advice would be great I have been stuck on this for some time.

if(issueSubTasks.size() > 0){
 
    logger.info(issueSubTasks.size()+" subtasks detected, updating fields on subtasks")
 
    for(issueSubTask in issueSubTasks){
      //Update each sub-task only if assignee was the same as the old or is empty
      if(issueSubTask.fields.assignee.displayName.equals(oldAssignee))
      {
        result = put('/rest/api/2/issue/'+issueSubTask.key)
             .header('Content-Type', 'application/json')
             .body([
             fields:[
                 assignee: issue.fields.assignee
             ]
        ])
       .asString()
       logger.info("subtask updated: "+issueSubTask.key)
     }
   }
 }  

Again, as long as there are no "unassigned' issues going in to this, it works fine. This was the base code before running in to the issue with unassigned, where I tried all the above changes, with no success. 

[Marc Minten (EVS)]

Did you try ... issue.assignee .... ? (without the ".fields." ?)

[Andrew Zibuda]

issue.assignee does not exist