redeclare_on_non_redeclaring_member

The {0} doesn't redeclare a {0} declared in a superinterface.

The analyzer produces this diagnostic when a member of an extension type is annotated with @redeclare, but none of the implemented interfaces has a member with the same name.

The following code produces this diagnostic because the member n declared by the extension type E is annotated with @redeclare, but C doesn't have a member named n:

import 'package:meta/meta.dart';

class C {
  void m() {}
}

extension type E(C c) implements C {
  @redeclare
  void n() {}
}

If the annotated member has the right name, then remove the annotation:

class C {
  void m() {}
}

extension type E(C c) implements C {
  void n() {}
}

If the annotated member is suppose to replace a member from the implemented interfaces, then change the name of the annotated member to match the member being replaced:

import 'package:meta/meta.dart';

class C {
  void m() {}
}

extension type E(C c) implements C {
  @redeclare
  void m() {}
}

Unless stated otherwise, the documentation on this site reflects Dart 3.8.1. Page last updated on 2025-05-08. View source or report an issue.