Require fields in subtasks

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Use this script as a workflow transition validator to allow transition only if a field in the subtask is populated.

string [] subtasks = subtasks(key);
boolean hasField = false;
string errorMsg = "You must have a value for the Fruit field in a subtask entered before this issue can be completed.";

for(string st in subtasks) {
    if(isNotNull(%st%.fruit)) {
        hasField = true;
    }
}

if(hasField == false) {
   return false, "error", errorMsg;
}