TypeError：无法添加属性 0，object 不可扩展

Question

how to solve this problem? I'm retrieving data from firestore database.

TypeError: Cannot add property 0, object is not extensible

Below is my code pushing the data to my events array but encountered this error:

 let events: any = [];

  const q = query(collection(DB, `events/${userType}/${uid}`));
  onSnapshot(q, (querySnapshot) => {
    querySnapshot.forEach((doc) => {
      events.push({ ...doc.data() });
    });
  });
  return events;

Answer 1

Declare your events array and handle your return functionality within the onSnapshot method.

const q = query(collection(DB, `events/${userType}/${uid}`));
onSnapshot(q, (querySnapshot) => {
 let events: any = [];
 querySnapshot.forEach((doc) => {
   events.push({ ...doc.data() });
 });
 setEventsState(events)
});
return;