createReducerを使用したReducerの書き方 - パート2

counter.jsx

export default createReducer(initialState, {
  [types.INCREMENT](state) {
    return Object.assign({}, state, {value: state.value + 1});
  },
  [types.DECREMENT](state) {
    return Object.assign({}, state, {value: state.value - 1});
  },
});

index.jsx(変更なし)

import { combineReducers } from 'redux';
import counter from './counter';

const rootReducer = combineReducers({
  counter,
});

export default rootReducer;