Cannot read properties of undefined (reading 'app')

Question

Im trying to implement the firebase SDK to my Flutter web project.

But as i try to start to application the following error appear:

TypeError: Cannot read properties of undefined (reading 'app')
    at Object.app$ [as app] (http://localhost:49235/packages/firebase_core_web/src/interop/core.dart.lib.js:31:101)
    at initializeApp (http://localhost:49235/packages/firebase_core_web/firebase_core_web.dart.lib.js:108:25)
    at initializeApp.next (<anonymous>)
    at runBody (http://localhost:49235/dart_sdk.js:39250:34)
    at Object._async [as async] (http://localhost:49235/dart_sdk.js:39281:7)
    at firebase_core_web.FirebaseCoreWeb.new.initializeApp (http://localhost:49235/packages/firebase_core_web/firebase_core_web.dart.lib.js:85:20)
    at initializeApp (http://localhost:49235/packages/firebase_core/firebase_core.dart.lib.js:104:59)
    at initializeApp.next (<anonymous>)
    at runBody (http://localhost:49235/dart_sdk.js:39250:34)
    at Object._async [as async] (http://localhost:49235/dart_sdk.js:39281:7)
    at Function.initializeApp (http://localhost:49235/packages/firebase_core/firebase_core.dart.lib.js:103:20)
    at main$ (http://localhost:49235/packages/oikos_web_ec/src/widgets/modals/links/delteLink.dart.lib.js:26076:36)
    at main$.next (<anonymous>)
    at runBody (http://localhost:49235/dart_sdk.js:39250:34)
    at Object._async [as async] (http://localhost:49235/dart_sdk.js:39281:7)
    at main$ (http://localhost:49235/packages/oikos_web_ec/src/widgets/modals/links/delteLink.dart.lib.js:26074:18)
    at main (http://localhost:49235/web_entrypoint.dart.lib.js:39:29)
    at main.next (<anonymous>)
 at http://localhost:49235/dart_sdk.js:39230:33
    at _RootZone.runUnary (http://localhost:49235/dart_sdk.js:39087:58)
    at _FutureListener.thenAwait.handleValue (http://localhost:49235/dart_sdk.js:34073:29)
    at handleValueCallback (http://localhost:49235/dart_sdk.js:34633:49)
    at Function._propagateToListeners (http://localhost:49235/dart_sdk.js:34671:17)
    at _Future.new.[_completeWithValue] (http://localhost:49235/dart_sdk.js:34513:23)
    at http://localhost:49235/dart_sdk.js:33724:46
    at _RootZone.runUnary (http://localhost:49235/dart_sdk.js:39087:58)
    at _FutureListener.then.handleValue (http://localhost:49235/dart_sdk.js:34073:29)
    at handleValueCallback (http://localhost:49235/dart_sdk.js:34633:49)
    at Function._propagateToListeners (http://localhost:49235/dart_sdk.js:34671:17)
    at _Future.new.[_completeWithValue] (http://localhost:49235/dart_sdk.js:34513:23)
    at async._AsyncCallbackEntry.new.callback (http://localhost:49235/dart_sdk.js:34536:35)
    at Object._microtaskLoop (http://localhost:49235/dart_sdk.js:39374:13)
    at _startMicrotaskLoop (http://localhost:49235/dart_sdk.js:39380:13)
    at http://localhost:49235/dart_sdk.js:34887:9

Thats the script I use in the index.html File

 <script type="module">
        // Import the functions you need from the SDKs you need
        import { initializeApp } from "https://www.gstatic.com/firebasejs/8.10.0/firebase-app.js";

        // Your web app's Firebase configuration
        const firebaseConfig = {
            apiKey: "-----....-----",
            authDomain: "-----....-----",
            projectId: "-----....-----",
            storageBucket: "-----....-----",
            messagingSenderId: "-----....-----",
            appId: "-----....-----"
        };

        // Initialize Firebase
        const app = initializeApp(firebaseConfig);
    </script>

I also init everything properly at the beginning of the app with:

void main() async {
  WidgetsFlutterBinding.ensureInitialized();
  await Firebase.initializeApp();
  runApp(MyApp());
}

Does someone now how to fix this error?

Solution 1

I was having this issue and solved this changing the script in the index.html to this

<script src="https://www.gstatic.com/firebasejs/8.10.0/firebase-app.js"></script>
<script src="https://www.gstatic.com/firebasejs/8.10.0/firebase-auth.js"></script>
<script src="https://www.gstatic.com/firebasejs/8.10.0/firebase-firestore.js"></script>
  <script src="https://www.gstatic.com/firebasejs/8.10.0/firebase-storage.js"></script>

  <script>
    // Import the functions you need from the SDKs you need

    // TODO: Add SDKs for Firebase products that you want to use
    // https://firebase.google.com/docs/web/setup#available-libraries

    // Your web app's Firebase configuration
    const firebaseConfig = {
      apiKey: "...",
      authDomain: "...",
      projectId: "...",
      storageBucket: "...",
      messagingSenderId: "...",
      appId: "..."
    };

    // Initialize Firebase
    firebase.initializeApp(firebaseConfig);
  </script>

Solution 2

Use this:

https://www.gstatic.com/firebasejs/8.6.1/firebase-app.js

in place of

https://www.gstatic.com/firebasejs/8.10.0/firebase-app.js

More info

Solution 3

I'm experiencing a similar issue with Firebase 9. Downgrade to 8.x and see if it's resolved.

Comments

[Peter Koltai]

I followed this guide and works fine for me.