flutter: check bloc updates

main.dart

import 'package:flutter/material.dart';
import 'package:flutter_bloc/flutter_bloc.dart';

void main() {
  runApp(const MyApp());
}

class MyApp extends StatelessWidget {
  const MyApp({Key? key}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return const MaterialApp(
      home: MyHomePage(title: 'Flutter Demo Home Page'),
    );
  }
}

class MyHomePage extends StatefulWidget {
  const MyHomePage({Key? key, required this.title}) : super(key: key);

  final String title;

  @override
  State<MyHomePage> createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  @override
  Widget build(BuildContext context) {
    final state = MyState();
    final cubit = MyCubit(state);

    return Scaffold(
      appBar: AppBar(
        title: Text(widget.title),
      ),
      body: Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: <Widget>[
            //
            // create
            //
            BlocProvider(
              // key: UniqueKey(),
              create: (_) => MyCubit(state),
              child: BlocConsumer<MyCubit, MyState>(
                listener: (context, state) {},
                builder: (context, state) {
                  return Text('state1 is $state (${state.hashCode})');
                },
              ),
            ),
            //
            // value
            //
            BlocProvider.value(
              value: cubit,
              child: BlocConsumer<MyCubit, MyState>(
                // key: ValueKey(cubit),
                listener: (context, state) {},
                builder: (context, state) {
                  return Text('state2 is $state (${state.hashCode})');
                },
              ),
            ),
            //
            // Consumer in stateless widget
            //
            BlocProvider.value(
              value: MyCubit(state),
              child: MyStatelessWidget(),
            ),
            Text('should be: ${state.hashCode}'),

            // MyStatelessWidget(),
          ],
        ),
      ),
      floatingActionButton: FloatingActionButton(
        onPressed: _refresh,
        child: const Icon(Icons.refresh),
      ),
    );
  }

  void _refresh() {
    setState(() {});
  }
}

class MyStatelessWidget extends StatelessWidget {
  const MyStatelessWidget({Key? key}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return BlocConsumer<MyCubit, MyState>(
      // key: UniqueKey(),
      listener: (context, state) {},
      builder: (context, state) {
        return Text('state3 is $state (${state.hashCode})');
      },
    );
  }
}

class MyCubit extends Cubit<MyState> {
  MyCubit(super.initialState);
}

class MyState {}