bloc_test 9.1.7

A testing library which makes it easy to test blocs. Built to be used with the bloc state management package.

example/main.dart

import 'dart:async';

import 'package:bloc/bloc.dart';
import 'package:bloc_test/bloc_test.dart';
import 'package:test/test.dart';

// Mock Cubit
class MockCounterCubit extends MockCubit<int> implements CounterCubit {}

// Mock Bloc
class MockCounterBloc extends MockBloc<CounterEvent, int>
    implements CounterBloc {}

void main() {
  mainCubit();
  mainBloc();
}

void mainCubit() {
  group('whenListen', () {
    test("Let's mock the CounterCubit's stream!", () {
      // Create Mock CounterCubit Instance
      final cubit = MockCounterCubit();

      // Stub the listen with a fake Stream
      whenListen(cubit, Stream.fromIterable([0, 1, 2, 3]));

      // Expect that the CounterCubit instance emitted the stubbed Stream of
      // states
      expectLater(cubit.stream, emitsInOrder(<int>[0, 1, 2, 3]));
    });
  });

  group('CounterCubit', () {
    blocTest<CounterCubit, int>(
      'emits [] when nothing is called',
      build: () => CounterCubit(),
      expect: () => const <int>[],
    );

    blocTest<CounterCubit, int>(
      'emits [1] when increment is called',
      build: () => CounterCubit(),
      act: (cubit) => cubit.increment(),
      expect: () => const <int>[1],
    );
  });
}

void mainBloc() {
  group('whenListen', () {
    test("Let's mock the CounterBloc's stream!", () {
      // Create Mock CounterBloc Instance
      final bloc = MockCounterBloc();

      // Stub the listen with a fake Stream
      whenListen(bloc, Stream.fromIterable([0, 1, 2, 3]));

      // Expect that the CounterBloc instance emitted the stubbed Stream of
      // states
      expectLater(bloc.stream, emitsInOrder(<int>[0, 1, 2, 3]));
    });
  });

  group('CounterBloc', () {
    blocTest<CounterBloc, int>(
      'emits [] when nothing is added',
      build: () => CounterBloc(),
      expect: () => const <int>[],
    );

    blocTest<CounterBloc, int>(
      'emits [1] when CounterIncrementPressed is added',
      build: () => CounterBloc(),
      act: (bloc) => bloc.add(CounterIncrementPressed()),
      expect: () => const <int>[1],
    );
  });
}

class CounterCubit extends Cubit<int> {
  CounterCubit() : super(0);

  void increment() => emit(state + 1);
}

abstract class CounterEvent {}

class CounterIncrementPressed extends CounterEvent {}

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