simple store like redux

createStore.js

export default class createStore {
  constructor(state, actions) {
    this._currentState = state
    this._currentActions = actions
    this._currentListener = null

    return {
      getState: this.getState.bind(this),
      dispatch: this.dispatch.bind(this),
      subscribe: this.subscribe.bind(this)
    }
  }

  getState() {
    return this._currentState
  }

  dispatch(action) {
    this._currentState = this._currentActions(this.getState(), action)
    this._currentListener()
  }

  subscribe(listener) {
    this._currentListener = listener
    
    return () => {
      if(!this._currentListener) return
      this._currentListener = null
    }
  }
}

todo-actions.js

const todos = (state, action) => {
  const type = action.type
  
  action['FETCH_TODOS'] = Object.assign({}, state, { todos: action.payload.todos })
  
  return action[type]
}

export {
  todos
}

todo.js

import { createStore } from './createStore'
import { todos } from './todo-actions'

const ProductStore = new createStore({
  todos: []
}, todos)

class TODO extends Component {
  constructor(props, context) {
    ProductStore.subscribe(() => {
      const storeState = ProductStore.getState()
      this.setState(storeState)
    })
    
    this.state = ProductStore.getState()
  }
  
  fetch_todos() {
    
    ProductStore.dispatch({
      type: 'FETCH_TODOS',
      payload: {
        todos: [{
          name: 'foo'
        }]
      }
    })
    
  }
  
  render() {
    <div>
      <button onClick={this.fetch_todos}>get todos</button>
      <div>{ this.state.todos }</div>
    </div>
  }
}