Firebase - 即使没有添加文档，addDoc() 也返回成功

Question

New to Firebase. I have a basic React form that takes a user's email and sends it to Firestore using addDoc().

import { initializeApp } from "firebase/app";
import { getFirestore } from "@firebase/firestore"

const firebaseConfig = {
  ...
};
// Initialize Firebase
export const app = initializeApp(firebaseConfig);

export const db = getFirestore(app)

const emailsCollectionRef = collection(db, "emails");

const addEmail = async (data: { email: string; }) => {
        console.log("Sending data to firebase");
    try {    
        const result =  await addDoc(emailsCollectionRef, {email: data!.email});
        console.log("Document written with ID: ", result.id);

    } catch (e) {
        console.error("Error adding document: ", e);
      }
        
    }

When I pass the user's input using addDoc() in a try catch I get this in the console

Sending data to firebase
Document written with ID:  YFPaCvSjeBssvUAtdqSh

Which is fine, but if I purposefully try to make it fail like for example changing the name of the collection in emailsCollectionRef eg

const emailsCollectionRef = collection(db, "NoSuchCollection");

and run the function again I get the same success message.

In the Firebase docs it says that addDoc()

Returns:

Promise<DocumentReference<T>>

A Promise resolved with a DocumentReference pointing to the newly created document after it has been written to the backend (Note that it won't resolve while you're offline).

and under DocumentReference it says

A DocumentReference refers to a document location in a Firestore database and can be used to write, read, or listen to the location. The document at the referenced location may or may not exist .

If I want to check if the write was succesful I have to ignore DocumentReference and immediately after using addDoc() do a separate query to see if that ID actually exists.

My question is, is there a better way to check if the write was actually succesful since DocumentReference obviously cannot be trusted?

Answer 1

Collections are created automatically when you write the first document to is, so quite likely your addDoc call with the non-existing collection actually creates that collection.

If you want to prevent that, you can only allow writes to specific, known collections in your database'ssecurity rules , which are enforced on the server. At that point, the promise returns by addDoc will also reject/fail.