scoped-reducer.js

import ReactNative from 'react-native';
const { NavigationExperimental } = ReactNative;
const { Reducer: NavigationReducer } = NavigationExperimental;

const feedNavigation = NavigationReducer.StackReducer({
  getPushedReducerForAction: (action) => {
    if (action.type === 'push') {
      return (state) => (state || action.route);
    }
    return null;
  },
  initialState: {
    key: 'feed',
    index: 0,
    children: [
      {
        key: 'list',
        title: 'Items'
      },
    ],
  },
});

module.exports = (state, action) => {
  if (action.scope && action.scope !== 'feed') {
    return state;
  } else {
    return feedNavigation(state, action);
  }
};