JS Functional Programming : Currying Function 2

configure_store_middleware.js

// Dependency : http://redux.js.org/ 
// Dependency : https://egghead.io/lessons/javascript-redux-the-middleware-chain
// following store resolves promises before by injecting middlewares to store dispatch.

const promise = (store) => (next) => (action) => {
  if ( typeof action.then === 'function' ) {
    return action.then(next);
  }
  return next(action);
};

const logger = (store) => (next) => ( action ) => {
  console.group(action.type);
  console.log('prev state', store.getState());
  console.log('action', action);
  const returnValue = next(action);
  console.log('next state', store.getState());
  console.groupEnd(action.type);
  return returnValue;
};

const wrapDispatchWithMiddleWares = (store, middlewares) => {
  // enum in reverse in order to call function in series. 
  middlewares.slice().reverse().forEach( middleware => 
    store.dispatch = middleware(store)(store.dispatch) 
  );
};

const configureStore = () => {
  const store = createStore(todoApp);
  const middlewares = [promise];
  middlewares.push(logger);
  wrapDispatchWithMiddleWares(store, middlewares);
  return store;
}