Firebaseerror: expected first argument to collection() to be a collectionreference, a documentreference or firebasefirestore

Error: expected first argument to collection() to be a collection reference, a document reference, or firebase.firestore.

Explanation:

This error occurs when the first argument passed to the collection() method in Firebase is not a valid collection reference, document reference, or the firebase.firestore object.

The collection() method in Firebase is used to retrieve a reference to a collection in the Firestore database. It expects a valid reference as its first argument.

Examples:

• Passing a valid collection reference:

const db = firebase.firestore();
const collectionRef = db.collection('users');

• Passing a valid document reference:

const db = firebase.firestore();
const docRef = db.collection('users').doc('user1');

• Passing the firebase.firestore object:

const db = firebase.firestore();
const firestore = firebase.firestore;

Make sure that the first argument passed to the collection() method is either a valid collection reference, document reference, or the firebase.firestore object to resolve this error.