rxjs-store.js

const stream$ = new Rx.BehaviorSubject()
const createStore = (rootReducer, initialState) => stream$
  .mergeMap(ensureStream)
  .scan(rootReducer, initialState)

const dispatch = (actionType, data) => stream$
  .next({ type: actionType, payload: data})

const isStream = (value) => (value instanceof Rx.Observable)
const ensureStream = (value) => (isStream(value) ? action : Rx.Observable.of(value))
const createAction = (actionType) => { return (data) => { dispatcher(actionType, data) } }

const dispatch = (actionType, data) => {
  stream$.next({ type: actionType, payload: data})
  if (isStream(data)) { stream$.next(data) }
}

const fetchContacts = createAction(‘Fetch’);
const loadContacts = createAction(‘Load’);

let source = Rx.Observable
  .fromPromise(
    fetch(url)
      .then(resp => resp.json())
    )
  .map(list => loadContacts(list))

fetchContacts(source)