invalid_reopen_annotation
The annotation '@reopen' can only be applied to a class that opens capabilities that the supertype intentionally disallows.
Description
#The analyzer produces this diagnostic when a @reopen
annotation has been
placed on a class or mixin that does not remove restrictions placed on the
superclass.
Example
#The following code produces this diagnostic because the class B
is
annotated with @reopen
even though it doesn't expand the ability of A
to be subclassed:
dart
import 'package:meta/meta.dart';
sealed class A {}
@reopen
class B extends A {}
Common fixes
#If the superclass should be restricted in a way that the subclass would change, then modify the superclass to reflect those restrictions:
dart
import 'package:meta/meta.dart';
interface class A {}
@reopen
class B extends A {}
If the superclass is correct, then remove the annotation:
dart
sealed class A {}
class B extends A {}