2017/06/06 [Medium] Use Selectors in Redux for Great Good

01_simple_selector.js

const initialState = {
  todos: []
}

const reducer = (state = initialState, action = {}) => {
  if (action.type === 'ADD_TODO') {
      return {
        ...state,
        todos: [...state.todos, action.payload]
      }
  }
      
  return state
}
      
const allTodos = (state) => state.todos