使用Firebase Auth和React Native增加内存使用量

Question

I am trying to add Firebase Authentication functionality to my React Native app. As FirebaseAuth is loaded asynchronously, the onAuthStateChanged must be used to listen for changes, as implemented here:

  async componentDidMount() {
      if (!firebase.apps.length) { firebase.initializeApp(ApiKeys.FirebaseConfig); }


      firebase.auth().onAuthStateChanged((user) => {
          this.setState({
              isAuthenticationReady: true, isAuthenticated: !!user
          });
      });
}

Is there a problem with my implementation which causes increasing memory usage or is is a problem with the firebase-js-sdk? Additionally, are there any alternatives to the code which provide the same functionality?

(I am using Expo and the version 5.5.0 of the Firebase JS SDK)

Answer 1

The only thing I spot is that you should probably stop listening after the component unmounts. The method you're calling returns a function you can call to unsubscribe to the events. Something like:

componentDidMount() {
    this.onAuthStateChangedUnsubscribe = 
        firebase.auth().onAuthStateChanged((user) => {
            this.setState({
                isAuthenticationReady: true, isAuthenticated: !!user
            });
        });
}

componentWillUnmount() {
    if (this.onAuthStateChangedUnsubscribe) this.onAuthStateChangedUnsubscribe();
}