flutter_leak_radar_lint 0.1.2

Custom lint rules for Flutter/Dart: undisposed controllers, uncancelled subscriptions, discarded listen results, and more memory-leak patterns.

example/README.md

flutter_leak_radar_lint example

This example is a small Flutter package whose lib/ holds intentionally leaky (and correctly-cleaned-up) widgets — one folder per rule — so you can see each lint fire in your IDE and try the auto-fixes:

lib/
├── undisposed_controller/        # controller/FocusNode never disposed
├── uncancelled_subscription/     # StreamSubscription never cancelled
├── uncancelled_timer/            # Timer never cancelled
├── unclosed_stream_controller/   # StreamController never closed
├── missing_remove_listener/      # addListener with no removeListener
├── discarded_listen_result/      # stream.listen(...) result discarded
└── bloc_uncancelled_subscription/ # subscription in a Bloc/Cubit not cancelled

Enable the plugin

# pubspec.yaml
dev_dependencies:
  custom_lint: ^0.8.1
  flutter_leak_radar_lint: ^0.1.0

# analysis_options.yaml
analyzer:
  plugins:
    - custom_lint

Then run dart run custom_lint (or just open the files in your IDE).

What a rule catches

// FLAGGED by `undisposed_controller`: created in a State, never disposed.
class _BadState extends State<MyWidget> {
  final _controller = TextEditingController();

  @override
  Widget build(BuildContext context) => TextField(controller: _controller);
}

// OK: disposed in dispose().
class _GoodState extends State<MyWidget> {
  final _controller = TextEditingController();

  @override
  void dispose() {
    _controller.dispose();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) => TextField(controller: _controller);
}

Most rules ship an auto-fix — invoke your IDE's quick-fix on the highlighted field to insert the matching dispose() / cancel() / close() call.