reducer.js

import { Types } from './action'

const initialState = {
  todos: []
}

const reducer = (state=initialState, action) => {
  switch(action.type){
    case Types.ADD_TODO: {
      const id = state.todos.length + 1
      const todo = { id, todo: action.payload }
      state.todos.push(todo)
      return state
    }
    case Types.DELETE_TODO: {
      const filteredTodos = state.todos.filter((todo) => {
          return todo.id !== Number(action.payload) 
      })
      return { todos: filteredTodos }; 
    }
    default: return state
  }
}

export default reducer;