`Firebase` package was successfully found. However, this package itself specifies a `main` module field that could not be resolved

I’m trying to read and write to firestore, use firebase’s authentication, and firebase’s storage within a expo managed react-native application.

Full Error:

While trying to resolve module `firebase` from file `C:UsersjoshuDesktopVSProjectsVolleyballConnectfirebase.js`, the package `C:UsersjoshuDesktopVSProjectsVolleyballConnectnode_modulesfirebasepackage.json` was successfully found. However, this package itself specifies a `main` module field that could not be resolved (`C:UsersjoshuDesktopVSProjectsVolleyballConnectnode_modulesfirebaseindex`. Indeed, none of these files exist:

  * C:UsersjoshuDesktopVSProjectsVolleyballConnectnode_modulesfirebaseindex(.native|.android.ts|.native.ts|.ts|.android.tsx|.native.tsx|.tsx|.android.js|.native.js|.js|.android.jsx|.native.jsx|.jsx|.android.json|.native.json|.json)
  * C:UsersjoshuDesktopVSProjectsVolleyballConnectnode_modulesfirebaseindexindex(.native|.android.ts|.native.ts|.ts|.android.tsx|.native.tsx|.tsx|.android.js|.native.js|.js|.android.jsx|.native.jsx|.jsx|.android.json|.native.json|.json)

My firebase config file:

import firebase from "firebase";
import { initializeApp } from "firebase/app";
import "firebase/firestore";
import "firebase/auth";
import "firebase/storage";

// I'm using the example key here, I have the correct config
const firebaseConfig = {
  apiKey: "api-key",
  authDomain: "project-id.firebaseapp.com",
  databaseURL: "https://project-id.firebaseio.com",
  projectId: "project-id",
  storageBucket: "project-id.appspot.com",
  messagingSenderId: "sender-id",
  appId: "app-id",
  measurementId: "G-measurement-id",
};

if (firebase.apps.length === 0) {
  initializeApp(firebaseConfig);
}

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

export { db, auth, storage };

I installed the firebase package with:

expo install firebase

Any help would be greatly appreciated. Thank you!

Answer

To reduce the size of the app, firebase SDK (v9.0.0) became modular. You can no longer do the import statement like before on v8.

You have two options.

1. Use the backwards compatible way. (it will be later removed):

This:

import firebase from 'firebase/app';
import 'firebase/auth';
import 'firebase/firestore';

Should be changed to:

// v9 compat packages are API compatible with v8 code
import firebase from 'firebase/compat/app';
import 'firebase/compat/auth';
import 'firebase/compat/firestore';

2. Refactor your code now.

From this:

import firebase from "firebase/compat/app";
import "firebase/compat/auth";

const auth = firebase.auth();
auth.onAuthStateChanged(user => { 
  // Check for user status
});

To this:

import { getAuth, onAuthStateChanged } from "firebase/auth";

const auth = getAuth(firebaseApp);
onAuthStateChanged(auth, user => {
  // Check for user status
});

You should definitely check the documentation