Redux example for dart & flutter with testing

internet_manager_test.dart

import 'package:equatable/equatable.dart';
import 'package:flutter/material.dart';
import 'package:flutter_redux/flutter_redux.dart';
import 'package:flutter_test/flutter_test.dart';
import 'package:meta/meta.dart';
import 'package:redux/redux.dart';

/// STATE:
@immutable
class AppState extends Equatable {
  final bool isInternetAvailable;

  AppState({this.isInternetAvailable});

  factory AppState.initial() {
    return AppState(isInternetAvailable: false);
  }

  AppState copyWith({bool isInternetAvailable}) {
    return AppState(
      isInternetAvailable: isInternetAvailable ?? this.isInternetAvailable,
    );
  }

  @override
  List<Object> get props => [this.isInternetAvailable];

  @override
  bool get stringify => true;
}

/// ACTIONS:
enum InternetAction { IS_ONLINE, IS_OFFLINE }

/// REDUCERS:
bool internetReducer(bool state, InternetAction action) {
  if (action is InternetAction) {
    return action == InternetAction.IS_ONLINE;
  } else {
    return state;
  }
}

AppState appReducer(AppState state, action) {
  return state.copyWith(
    isInternetAvailable: internetReducer(state.isInternetAvailable, action),
  );
}

/// UI:
class InternetCheckerWidget extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(),
      body: StoreConnector<AppState, bool>(
        converter: (store) => store.state.isInternetAvailable,
        builder: (context, isInternetAvailable) {
          final String status = isInternetAvailable ? 'ONLINE' : 'OFFLINE';
          return Text('Status: $status');
        },
      ),
    );
  }
}

/// WIDGET TESTING:
void main() {
  final store = Store<AppState>(appReducer, initialState: AppState.initial());

  Widget buildApp() {
    return MaterialApp(
      home: StoreProvider<AppState>(
        store: store,
        child: InternetCheckerWidget(),
      ),
    );
  }

  testWidgets('builds successfully', (WidgetTester tester) async {
    await tester.pumpWidget(buildApp());
    expect(find.byType(Text), findsOneWidget);
  });

  testWidgets('"Status: ONLINE" when online', (WidgetTester tester) async {
    store.dispatch(InternetAction.IS_ONLINE);
    await tester.pumpWidget(buildApp());
    expect(find.text('Status: ONLINE'), findsOneWidget);
  });

  testWidgets('"Status: OFFLINE" when offline', (WidgetTester tester) async {
    store.dispatch(InternetAction.IS_OFFLINE);
    await tester.pumpWidget(buildApp());
    expect(find.text('Status: OFFLINE'), findsOneWidget);
  });
}