import 'package:flutter_bloc/flutter_bloc.dart';
import 'package:flutter_test/flutter_test.dart';
import 'package:halkyon_app/halkyon_app.dart';

/// The states [cubit] emits while [step] runs, in order.
Future<List<S>> statesOf<S>(
  BlocBase<S> cubit,
  Future<void> Function() step,
) async {
  final states = <S>[];
  final listening = cubit.stream.listen(states.add);
  await step();
  // A cubit's stream hands its states on in a microtask.
  await Future<void>.delayed(Duration.zero);
  await listening.cancel();
  return states;
}

/// The states [cubit] emits as [step] (not awaited: it emits at once).
Future<List<S>> statesNow<S>(BlocBase<S> cubit, void Function() step) =>
    statesOf(cubit, () async => step());

/// A refusal of [problem].
Matcher refusedAs(PasswordProblem problem) => isA<PasswordFailed>().having(
  (failed) => failed.problem,
  'problem',
  problem,
);