[Firebase Storage] getDownloadURL return type

[awhitford]

Why is the return type for getDownloadURL a dynamic instead of a String?

  /// Asynchronously retrieves a long lived download URL with a revokable token.
  /// This can be used to share the file with others, but can be revoked by a
  /// developer in the Firebase Console if desired.
  Future<dynamic> getDownloadURL() async {
    return await FirebaseStorage.channel.invokeMethod<dynamic>(
        "StorageReference#getDownloadUrl", <String, String>{
      'app': _firebaseStorage.app?.name,
      'bucket': _firebaseStorage.storageBucket,
      'path': _pathComponents.join("/"),
    });
  }

In practice, the runtimeType seems to be String. Could it be something else?

[iapicca]

Hi @awhitford
You might want to check the documentation regarding invokeMethod
Closing, as this isn't an issue with Flutter itself,
if you disagree please write in the comments and I will reopen it
Thank you

[awhitford]

Please reopen. I don't understand why the return type is not well documented.

The implementation would have two tiny changes:

  /// Asynchronously retrieves a long lived download URL with a revokable token.
  /// This can be used to share the file with others, but can be revoked by a
  /// developer in the Firebase Console if desired.
  Future<String> getDownloadURL() async {
    return await FirebaseStorage.channel.invokeMethod<String>(
        "StorageReference#getDownloadUrl", <String, String>{
      'app': _firebaseStorage.app?.name,
      'bucket': _firebaseStorage.storageBucket,
      'path': _pathComponents.join("/"),
    });
  }

Note that the Java API has a return type is a Uri, but the Flutter/Dart API seems to be returning a String. Should it also be returning a Uri?

The Swift API seems to indicate that maybe the return value is either a URL (success) or an Error -- so then wouldn't a Future<String> or Future<Uri> be a fine equivalent?

If dynamic is appropriate because the return type may be String or something else, the developer needs to know to handle it appropriately. Right now, I am assuming that I am getting a String, but I don't like to assume.

[awhitford]

I appreciate the thumbs up support. This looks like a trivial fix; I'm surprised that this is still outstanding. Is there a way that I can help with a pull request?

[Salakar]

On the latest release getDownloadURL does return Future<String>: https://github.com/FirebaseExtended/flutterfire/blob/master/packages/firebase_storage/firebase_storage/lib/src/reference.dart#L57