avoid_bloc_public_methods

v0.4.0 Warning Bloc / Riverpod

This rule flags public methods, getters, and setters declared in Bloc classes (but not Cubits). Blocs should only expose state changes through events via the add method, not through custom public members.

Why use this rule

The whole point of the Bloc pattern is that state changes are driven by events. When you add public methods like increment() or reset() to a Bloc, you bypass the event-driven architecture and lose the ability to trace, replay, and log state transitions. If you need public methods, you probably want a Cubit instead. Private members, overrides, and static members are all allowed.

See also: Bloc best practices | When to use Cubit vs Bloc

Don’t

import 'package:bloc/bloc.dart';

abstract class CounterEvent {}

class Increment extends CounterEvent {}

class Decrement extends CounterEvent {}

class CounterBloc extends Bloc<CounterEvent, int> {
  CounterBloc() : super(0) {
    on<Increment>((event, emit) => emit(state + 1));
    on<Decrement>((event, emit) => emit(state - 1));
  }

  // Public method bypasses event-driven pattern
  void increment() {}

  // Public getter exposes internal state
  int get currentValue => state;

  // Public setter allows direct mutation
  set currentValue(int value) {}
}

Do

import 'package:bloc/bloc.dart';

abstract class CounterEvent {}

class Increment extends CounterEvent {}

class Decrement extends CounterEvent {}

class CounterBloc extends Bloc<CounterEvent, int> {
  CounterBloc() : super(0) {
    on<Increment>((event, emit) => emit(state + 1));
    on<Decrement>((event, emit) => emit(state - 1));
  }

  // Private methods are fine
  void _handleReset() {}

  // Overrides are fine
  @override
  void onChange(Change<int> change) {
    super.onChange(change);
  }

  // Static methods are fine
  static CounterEvent createIncrement() => Increment();
}

Configuration

To disable this rule:

plugins:
  many_lints:
    diagnostics:
      avoid_bloc_public_methods: false