title: React Native Firebase Facebook login works, but is not authenticated after successful log in
body: <p>I have implemented facebook authentication via react-native-firebase. When the user logs in the user shows up as authenticated with facebook in the dashboard which is great.</p>
  
  <p>My problem is, I cant use firebase.auth().currentUser to get the signed in user like I was able to do with email and password authentication.</p>
  
  <p>The user shows up as null and I am not able to write to my database (even though it says I have successfully signed in).</p>
  
  <p>Here is what my function looks like to handle the login:</p>
  
  <pre><code>  onLoginFacebook = () =&gt; {
      LoginManager.logInWithPermissions(['public_profile', 'email'])
        .then(result =&gt; {
          if (result.isCancelled) {
            alert('cancelled');
          }
          console.log(
            `login success with permissions: ${result.grantedPermissions.toString()}`,
          );
          return AccessToken.getCurrentAccessToken();
        })
        .then(data =&gt; {
          const credential = RNFirebase.auth.FacebookAuthProvider.credential(
            data.accessToken,
          );
          return RNFirebase.auth().signInWithCredential(credential);
        })
        .then(currentFBUser =&gt; {
          console.log(`Facebook Login with user: ${JSON.stringify(currentFBUser)}`);
          //NOT WORKING 
          const {currentUser} = firebase.auth();
          const uid = currentUser.uid;
          //NOT WORKING
          firebase.auth().onAuthStateChanged(authedUser =&gt; {
            if (authedUser) {
              Actions.home();
            } else {
              Actions.checkAuth();
            }
          });
        })
        .catch(error =&gt; {
          console.log(`Login failed with ${error}`);
        });
    };
  </code></pre>
  
  <p>I appreciate all the help I can get with this issue, cheers!</p>