Executing Firebase app 3 times results in crash

[srawlins]

Take this app:

import 'package:flutter/material.dart';
import 'package:firebase/firebase.dart';
import 'package:firebase/firestore.dart' as fs;

void main() async {
  try {
    initializeApp(
      apiKey: ...,
      authDomain: ...,
      projectId: ...,
      storageBucket: ...,
      messagingSenderId: ...,
      appId: ...,
      measurementId: ...
    );
  } catch (ex) {
    print('App was already initialized...');
  }
    
  fs.Firestore store = firestore();
  fs.CollectionReference ref = store.collection('bandnames');

  runApp(
    MaterialApp(
      debugShowCheckedModeBanner: false,
      home: Scaffold(
        appBar: AppBar(
          title: Text('Potential names for my band'),
        ),
        body: MyWidget(ref.onSnapshot),
        floatingActionButton: AuthFab(),
      ),
    ),
  );
}

class MyWidget extends StatelessWidget {
  final Stream<fs.QuerySnapshot> stream;

  const MyWidget(this.stream);

  @override
  Widget build(BuildContext context) {
    return StreamBuilder<fs.QuerySnapshot>(
        stream: stream,
        builder: (context, snapshot) {
          if (snapshot.hasError) {
            return Center(
              child: Text('$snapshot.error'),
            );
          } else if (!snapshot.hasData) {
            return Center(
              child: SizedBox(
                width: 50,
                height: 50,
                child: CircularProgressIndicator(),
              ),
            );
          }
          return ListView.builder(
              itemCount: snapshot.data!.docs.length,
              itemBuilder: (context, i) {
                return ListTile(
                  leading: Text('${snapshot.data!.docs[i].data()['votes']}'),
                  title: Text('${snapshot.data!.docs[i].data()['name']}'),
                );
              });
        });
  }
}

class AuthFab extends StatefulWidget {
  @override
  State<StatefulWidget> createState() => AuthFabState();
}

class AuthFabState extends State<AuthFab> {
  Future<UserCredential>? authFuture;

  @override
  Widget build(BuildContext build) {
    if (authFuture == null) {
      return FloatingActionButton(
        onPressed: () {
          setState(() {
            authFuture = auth().signInWithEmailAndPassword(
              'blah@blah.com',
              'password',
            );
          });
        },
        child: Icon(Icons.person_outline),
      );
    }

    return FloatingActionButton(
      onPressed: () {},
      child: FutureBuilder<UserCredential>(
        future: authFuture,
        builder: (context, snapshot) {
          if (snapshot.hasError) {
            return Icon(Icons.error);
          } else if (!snapshot.hasData) {
            return Icon(Icons.refresh);
          }

          return Icon(Icons.person);
        },
      ),
    );
  }
}

running the app 3 times, without changing the code, results in this error:

Uncaught (in promise) Error: Expected a value of type 'Firestore?', but got one of type 'Firestore'
    at Object.throw_ [as throw] (dart_sdk.js:5041)
    at Object.castError (dart_sdk.js:5014)
    at Object.cast [as as] (dart_sdk.js:5323)
    at dart.NullableType.new.as (dart_sdk.js:6830)
    at Expando.new._get (dart_sdk.js:118824)
    at Function.getInstance (<anonymous>:3609:17)
    at Object.firestore$0 [as firestore] (<anonymous>:3559:33)
    at main$ (<anonymous>:692:29)
    at main$.next (<anonymous>)
    at runBody (dart_sdk.js:37422)
    at Object._async [as async] (dart_sdk.js:37453)
    at Object.main$0 [as main] (<anonymous>:682:18)
    at main$ (<anonymous>:584:12)
    at main$.next (<anonymous>)
    at dart_sdk.js:37403
    at _RootZone.runUnary (dart_sdk.js:37274)
    at _FutureListener.thenAwait.handleValue (dart_sdk.js:32530)
    at handleValueCallback (dart_sdk.js:33057)
    at Function._propagateToListeners (dart_sdk.js:33095)
    at _Future.new.[_completeWithValue] (dart_sdk.js:32943)
    at dart_sdk.js:32194
    at _RootZone.runUnary (dart_sdk.js:37274)
    at _FutureListener.then.handleValue (dart_sdk.js:32530)
    at handleValueCallback (dart_sdk.js:33057)
    at Function._propagateToListeners (dart_sdk.js:33095)
    at _Future.new.[_completeWithValue] (dart_sdk.js:32943)
    at async._AsyncCallbackEntry.new.callback (dart_sdk.js:32964)
    at Object._microtaskLoop (dart_sdk.js:37526)
    at _startMicrotaskLoop (dart_sdk.js:37532)
    at dart_sdk.js:33303

[srawlins]

CC @RedBrogdon This is the app you shared.

I cannot make heads or tails of that error. Is there a way to de-obfuscate it? One possibility is that there are "two types" called "Firestore". And "two types" may mean two actually different types declared in two different places, or a single type which is imported in two different ways.

[srawlins]

Potential related issue: dart-lang/sdk#37259, hard to say though...

[srawlins]

@nshahan deduced that this may be related to an Expando + Hot Restart bug which should be fixed in recent Flutter beta. Bug does indeed seem fixed with 2.14.0-301.2.beta.

I'll leave this open though until it is fixed in stable. :/

[RedBrogdon]

@srawlins, has this one been resolved with the latest SDK release?

[srawlins]

Not sure. I want to fix #2033 and then circle back here.

[srawlins]

OK this looks fixed. I can run the bandnames app over and over and no crash.