proper_super_calls

v0.4.0WarningFixConfigurableControl Flow

Warns when super lifecycle methods are called in the wrong order in State subclasses. Methods like initState, didUpdateWidget, activate, didChangeDependencies, and reassemble must call super first. Methods like deactivate and dispose must call super last.

Why use this rule

Flutter’s State lifecycle methods have a specific contract about when super should be called. Calling super.initState() after your own initialization code can lead to errors because the framework expects to set up its own state first. Conversely, calling super.dispose() before your cleanup code means your resources are released while the framework has already torn down its own state. The quick fix automatically moves the super call to the correct position.

See also: State.initState | State.dispose

Don’t

class _BadInitStateState extends State<BadInitState> {
  String _data = '';

  @override
  void initState() {
    _data = 'Hello'; // super.initState() should come before this
    super.initState();
  }

  @override
  Widget build(BuildContext context) => const SizedBox();
}

class _BadDisposeState extends State<BadDispose> {
  @override
  void dispose() {
    super.dispose(); // super.dispose() should come after cleanup
    debugPrint('cleanup');
  }

  @override
  Widget build(BuildContext context) => const SizedBox();
}

class _BadDeactivateState extends State<BadDeactivate> {
  @override
  void deactivate() {
    super.deactivate(); // super.deactivate() should come after cleanup
    debugPrint('deactivating');
  }

  @override
  Widget build(BuildContext context) => const SizedBox();
}

Do

class _GoodInitStateState extends State<GoodInitState> {
  String _data = '';

  @override
  void initState() {
    super.initState(); // First
    _data = 'Hello';
  }

  @override
  Widget build(BuildContext context) => const SizedBox();
}

class _GoodDisposeState extends State<GoodDispose> {
  @override
  void dispose() {
    debugPrint('cleanup');
    super.dispose(); // Last
  }

  @override
  Widget build(BuildContext context) => const SizedBox();
}

class _GoodDeactivateState extends State<GoodDeactivate> {
  @override
  void deactivate() {
    debugPrint('deactivating');
    super.deactivate(); // Last
  }

  @override
  Widget build(BuildContext context) => const SizedBox();
}

Turning this rule off

This rule is in the recommended preset, so it is on with preset: recommended or preset: opinionated. Add it to preset: core with proper_super_calls: true.

To turn it off:

rules:
  proper_super_calls: false

To keep the rule on but skip certain paths, use per-rule exclude.

Options

Projects with a state abstraction that does not extend Flutter’s State can opt that base class into this rule:

analysis_options.yaml
many_lints.yaml

many_lints:
  rules:
    proper_super_calls:
      state_base_classes: [AppState]

rules:
  proper_super_calls:
    state_base_classes: [AppState]

Option	Type	Default	Description
`state_base_classes`	list of strings	`[]`	Additional non-`State` base classes whose subclasses should be treated as state classes

avoid_cascade_after_if_null — Detect cascades after if-null operators without parentheses.
avoid_collapsible_if — Merge nested if statements with &&.
avoid_constant_conditions — Detect comparisons where both sides are constants.
avoid_constant_switches — Detect switch statements on constant expressions.