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prefer-immutable-bloc-events

added in: 1.25.0
warning
⚙️🛠
Free+

Warns when a Bloc event does not have the @immutable annotation.

info

If you keep your bloc events in separate files, consider using the include configuration option to scope the rule to only those files.

⚙️ Config​

Set name-pattern (default is Event$) to set a regular expression pattern for bloc event names.

analysis_options.yaml
dart_code_metrics:
  rules:
    - prefer-immutable-bloc-events:
        name-pattern: Event$

Example​

❌ Bad:

// LINT: Prefer adding '@immutable' to Bloc events.
sealed class CounterEvent {}

// LINT: Prefer adding '@immutable' to Bloc events.
class CounterIncrement extends CounterEvent {}

✅ Good:

@immutable
sealed class CounterEvent {}

@immutable
class CounterIncrement extends CounterEvent {}