redux-observable example

index.js

const Rx = require('rxjs/Rx');
const { createStore, applyMiddleware } = require('redux');
const { createEpicMiddleware, combineEpics } = require('redux-observable');

const inc = n => n + 1;

const reducer = function ({ count } = { count: 0 }, { type } = {}) {
  switch (type) {
    case "add":
      return { count: inc(count) };
    case "add async":
      return { count: inc(count) };
  }
  return { count };
};

const handleAdd = function (action$) {
  return action$
    .ofType("add")
    .delay(2000)
    .mapTo({ type: "add async" });
};

const logger = function (action$, { getState }) {
  return action$
    .forEach(_ => console.log(getState()));
};

const store = createStore(
  reducer,
  applyMiddleware(
    createEpicMiddleware(
      combineEpics(handleAdd, logger))));

store.dispatch({ type: "add" });

// { count: 1 }
// .. 2 second ..
// { count: 2 }