message: fix derivative bug
diff: @@ -7,7 +7,7 @@ const shouldEvaluateReducer = (listeners, before, after) =>
  if (acc) return true;
  else
  return (
  - JSON.stringify(before[currField]) !== JSON.stringify(after[currField])
  + JSON.stringify(before?.[currField]) !== JSON.stringify(after[currField])
  );
  }, false);
  @@ -23,14 +23,16 @@ const derivative = (
  utilFns: any;
  }) => any;
  }[]
  -) => async (change: functions.Change<functions.firestore.DocumentSnapshot>) => {
  +) => async (
  + change: functions.Change<functions.firestore.DocumentSnapshot>,
  +) => {
  try {
  const beforeData = change.before?.data();
  const afterData = change.after?.data();
  const ref = change.after ? change.after.ref : change.before.ref;
  const update = await functionConfig.reduce(
  async (accUpdates: any, currDerivative) => {
  - const shouldEval = shouldEvaluateReducer(
  + const shouldEval = (!beforeData && afterData) || shouldEvaluateReducer(
  currDerivative.listenerFields,
  beforeData,
  afterData
  