React: react-navigation / react-navigation-redux-helpers - 'Invariant Violation: Element type is invalid... at ExpoRootComponent'

Question

I'm trying to implement redux and navigation within a react native application, so I'm trying to follow the instructions for react-native-redux-helpers (here).

I seem to have been able to reach the Root class instantiation without any issues, but receive an error when the component attempts to load:

App.js:

import React from 'react';
import { StyleSheet, Text, View } from 'react-native';
import { createStore, combineReducers, applyMiddleware } from 'redux';
import { Provider, connect } from 'react-redux';
import rootReducer from './src/reducers/index';
import { createStackNavigator, createAppContainer } from 'react-navigation';
import { reduxifyNavigator, createReactNavigationReduxMiddleware, createNavigationReducer } from 'react-navigation-redux-helpers';

import LoginScreen from './src/screens/LoginScreen';
import NotesScreen from './src/screens/NotesScreen';

const AppNavigator = createStackNavigator({
  Login: {
        screen: LoginScreen
  },
  Notes: {
        screen: NotesScreen
  }
})

const navReducer = createNavigationReducer(AppNavigator);

const appReducer = combineReducers({
  rootReducer,
  navReducer
})

const middleware = createReactNavigationReduxMiddleware('root', state => state.nav);

const App = reduxifyNavigator(AppNavigator, 'root');

const mapStateToProps = state => ({
  state: state.nav
})

const AppWithNavigationState = connect(mapStateToProps)(App);

const store = createStore(appReducer, applyMiddleware(middleware));

class Root extends React.Component {
  render() {
        return (
              <Provider store={store}>
                    <AppWithNavigationState />
              </Provider>
        )
  }
}

Answer 1

you need to export your class like this;

export default class Root extends React.Component {
  render() {
    return (
          <Provider store={store}>
                <AppWithNavigationState />
          </Provider>
    );
  }
} 

Edit: Also you need to change your combine reducer;

const appReducer = combineReducers({
  rootReducer,
  nav: navReducer
})

So in your mapStateToProps, you can use state:state.nav