Unexpected text "return"

Question

I'm trying to implement an AuthService from a tutorial of Fireship (https://fireship.io/lessons/flutter-firebase-google-oauth-firestore/)

I copied exactly his AuthService:

  AuthService() {
    user = Observable(_auth.onAuthStateChanged);

    profile = user.switchMap((FirebaseUser u) => {
      if (u != null) {
        return _db.collection("users").document(u.uid).snapshots().map((snap) => snap.data);
      } else {
        return Observable.just({});
      }
    });
  }

I get these errors:

If I copy the code from his website (it's exactly the same) there are no errors. wtf? Can someone explain this or help? Thanks!

Answer 1

Change this:

    profile = user.switchMap((FirebaseUser u) => {

into this:

    profile = user.switchMap((FirebaseUser u) {

From the docs:

For functions that contain just one expression, you can use a shorthand syntax:

bool isNoble(int atomicNumber) => _nobleGases[atomicNumber] != null;

The => expr syntax is a shorthand for { return expr; }. The => notation is sometimes referred to as arrow syntax.