Redux - deriveState store enhancer

deriveState.js

const deriveState = state => {
  state.foo = "bar";
  return state;
}

const enhanceStore = createStore => (reducer, preloadedState, enhancer) => {
  const store = createStore(reducer, preloadedState, enhancer);
  const _originalGetState = store.getState;
  store.getState = () => deriveState(_originalGetState());
  return store;
};

export const store = createStore(
  reducer,
  initialState,
  enhanceStore
);