PreferSuperKeyRule class

Prefer super.key over Key? key with super(key: key) on Flutter widgets.

Since: v9.11.0 | Rule version: v1

Matches the Flutter framework style from Flutter 3.24 (PR #147621): forward the widget key with Dart super-parameter syntax instead of an explicit super constructor call.

Narrower than the stylistic rule prefer_super_parameters: only applies to classes that extend StatelessWidget, StatefulWidget, or a type whose name ends with Widget, and only for a Key-typed parameter named key. If you already enable prefer_super_parameters, you may get duplicate diagnostics on the same key: key forwarding; prefer one or the other for widget keys.

Detection logic lives in PreferSuperKeyDetection so the quick fix stays in lockstep with the rule.

Limitations: Only the unqualified type name Key is accepted (not import-prefix forms like widgets.Key). super(key: key) combined with other super arguments is not reported—only a sole key forward matches.

BAD:

class MyPage extends StatelessWidget {
  const MyPage({Key? key}) : super(key: key);
  // ...
}

GOOD:

class MyPage extends StatelessWidget {
  const MyPage({super.key});
  // ...
}

See: https://github.com/flutter/flutter/pull/147621