[v9.0.2 auth] INTERNAL ASSERTION FAILED: Expected a class definition

[bramvanneerven]

In an effort to reduce the dependencies of the authentication code I use, I tried the following:

// Works
import { getAuth } from 'firebase/auth';
const auth = getAuth(app);

// ERROR!
import { browserLocalPersistence, initializeAuth } from 'firebase/auth';
const auth = initializeAuth(app, { persistence: browserLocalPersistence });

Error output

Error: INTERNAL ASSERTION FAILED: Expected a class definition
    at debugFail ({***path***}/node_modules/.pnpm/@firebase+auth@0.17.2_@firebase+app@0.7.0/node_modules/@firebase/auth/dist/node/index-012195c6.js:535:11)
    at debugAssert ({***path***}/node_modules/.pnpm/@firebase+auth@0.17.2_@firebase+app@0.7.0/node_modules/@firebase/auth/dist/node/index-012195c6.js:546:9)
    at _getInstance ({***path***}/node_modules/.pnpm/@firebase+auth@0.17.2_@firebase+app@0.7.0/node_modules/@firebase/auth/dist/node/index-012195c6.js:568:5)
    at Array.map (<anonymous>)
    at _initializeAuthInstance ({***path***}/node_modules/.pnpm/@firebase+auth@0.17.2_@firebase+app@0.7.0/node_modules/@firebase/auth/dist/node/index-012195c6.js:637:80)
    at {***path***}/node_modules/.pnpm/@firebase+auth@0.17.2_@firebase+app@0.7.0/node_modules/@firebase/auth/dist/node/index-012195c6.js:6979:13
    at Component.instanceFactory ({***path***}/node_modules/.pnpm/@firebase+auth@0.17.2_@firebase+app@0.7.0/node_modules/@firebase/auth/dist/node/index-012195c6.js:6981:11)
    at Provider.getOrInitializeService ({***path***}/node_modules/.pnpm/@firebase+component@0.5.6/node_modules/@firebase/component/dist/index.cjs.js:342:39)
    at Provider.initialize ({***path***}/node_modules/.pnpm/@firebase+component@0.5.6/node_modules/@firebase/component/dist/index.cjs.js:264:29)
    at initializeAuth ({***path***}/node_modules/.pnpm/@firebase+auth@0.17.2_@firebase+app@0.7.0/node_modules/@firebase/auth/dist/node/index-012195c6.js:632:25)

package.json

  "dependencies": {
    "@chakra-ui/react": "^1.6.7",
    "@chakra-ui/theme-tools": "^1.2.0",
    "@emotion/react": "^11.4.1",
    "@emotion/styled": "^11.3.0",
    "@xstate/react": "^1.6.1",
    "common-tags": "^1.8.0",
    "firebase": "^9.0.2",
    "framer-motion": "^4.1.17",
    "next": "11.1.0",
    "react": "17.0.2",
    "react-dom": "17.0.2",
    "react-icons": "^4.2.0",
    "sharp": "^0.29.1",
    "xstate": "^4.23.4"
  },
  "devDependencies": {
    "@types/common-tags": "^1.8.1",
    "@types/react": "17.0.18",
    "eslint": "7.32.0",
    "eslint-config-next": "11.1.0",
    "eslint-plugin-import": "^2.24.2",
    "lint-staged": "^11.1.2",
    "prettier": "^2.4.0",
    "simple-git-hooks": "^2.6.1",
    "typescript": "4.3.5"
  },

The problem seems to be here:

firebase-js-sdk/packages/auth/src/core/util/instantiator.ts

Line 34 in cdada6c

debugAssert(cls instanceof Function, 'Expected a class definition');

I did have a quick look, but could not really find the actual problem myself.

[google-oss-bot]

I couldn't figure out how to label this issue, so I've labeled it for a human to triage. Hang tight.

[arneesh]

I am experiencing the same issue.

[jbalidiong]

Hi @bvanneerven, thanks for reporting this. I followed the steps and both codes for Auth is working. I was able to run the app by using this snippet:

import React, { useEffect } from 'react';
import { browserLocalPersistence, initializeAuth, onAuthStateChanged} from 'firebase/auth';
import { initializeApp} from 'firebase/app'
function App() {
  let firebaseApp;
  let firebaseAuth;

  useEffect(() => {
    let firebaseConfig = {
      apiKey: "",
      authDomain: "",
      projectId: "",
      storageBucket: "",
      messagingSenderId: "",
      appId: "",
      measurementId: ""
    };
    firebaseApp = initializeApp(firebaseConfig);    
    firebaseAuth = initializeAuth(firebaseApp,{persistence: browserLocalPersistence});

    onAuthStateChanged(firebaseAuth, (user) => {
      console.log('user', user);
      if (user) {
        // User is signed in, see docs for a list of available properties
        // https://firebase.google.com/docs/reference/js/firebase.User
        const uid = user.uid;
        console.log("User is signed in");
      } else {
        // User is signed out
        console.log("User is signed out");
      }
    });
  }, []);
}

Let me know if you're still experiencing the issue.

[arneesh]

@jbalidiong are you using client-side rendering? And development mode? I am facing this issue in production mode after running build, on dev mode without ssr it works fine.

[archevis]

Facing the same issue with Angular Universal SSR:

@firebase/auth: Auth (9.0.0): INTERNAL ASSERTION FAILED: Expected a class definition

All works fine in dev mode without SSR (that is, client-side rendering).

EDIT: No idea why it says 9.0.0, my package.json says "firebase": "^9.0.2"

EDIT 2: Initially I got the following error during server-side rendering when upgrading to firebase 9:

ERROR Error: Uncaught (in promise): ReferenceError: navigator is not defined
ReferenceError: navigator is not defined
    at Object.areCookiesEnabled (...)
    at SwitchMapSubscriber.<anonymous> (...)
    ...

So I tried adding a domino implementation to make navigator and other globals available:

const win = domino.createWindow(template);
global.window = win;
global.document = win.document;
global.navigator = win.navigator
...

Could the problem be domino related?

[bramvanneerven]

I am currently using the following workaround.

import { 
  browserLocalPersistence,
  inMemoryPersistence,
  indexedDBLocalPersistence,
  initializeAuth,
} from 'firebase/auth';

const auth = initializeAuth(app, {
  persistence:
    typeof window === 'undefined'
      ? inMemoryPersistence
      : [indexedDBLocalPersistence, browserLocalPersistence],
});

[jbalidiong]

@bvanneerven, I'll try and replicate this by following the additional information provided by @arneesh and @archevis. If I can replicate the issue, I can have a better look into it.

[arneesh]

For the time being, I am using @bvanneerven 's workaround.