i am building a google drive clone and i did add a remove function of a file. Unfortunately, when i did add "ref: doc.ref" to my code. My folders on the drive cannot be opened and when i click on them, it gives me this error message:

Here is my firebase.js code:

import firebase from "firebase/app"
import "firebase/auth"
import "firebase/firestore"
import "firebase/storage"

const app = firebase.initializeApp({
  apiKey: process.env.REACT_APP_FIREBASE_API_KEY,
  authDomain: process.env.REACT_APP_FIREBASE_AUTH_DOMAIN,
  databaseURL: process.env.REACT_APP_FIREBASE_DATABASE_URL,
  projectId: process.env.REACT_APP_FIREBASE_PROJECT_ID,
  storageBucket: process.env.REACT_APP_FIREBASE_STORAGE_BUCKET,
  messagingSenderId: process.env.REACT_APP_FIREBASE_MESSAGING_SENDER_ID,
  appId: process.env.REACT_APP_FIREBASE_APP_ID,
})


export const firestore = app.firestore()
export const database = {
  folders: firestore.collection("folders"),
  files: firestore.collection("files"),
  formatDoc: doc => {
    return { id: doc.id, ref: doc.ref, ...doc.data() } // ref:doc.ref is the reason i guess, beacause when i delete it, the folders are opening perfectly.
  },
  getCurrentTimestamp: firebase.firestore.FieldValue.serverTimestamp,
}
export const storage = app.storage()
export const auth = app.auth()
export default app