reactjs - Redux reducer todolist Immutable equivalent -

i'm trying rewrite redux todo example in immutable.js, far i've made initalstate immutable list , changed add , unshift rather spread operator, seems working fine. form immutable docs seem can use these unshift , push etc.. on list, think might ok?.

i've seen examples instead of .list() used .fromjs() wrapping object that's being push / unshift etc in .fromjs()

so, question

is that's required make immutable ?

const initialstate = immutable.list([{   text: 'use redux',   marked: false,   id: 0 }]);  export default function todos(state = initialstate, action) {   switch (action.type) {      case add_todo:     return state.unshift({       id: state.reduce((maxid, todo) => math.max(todo.id, maxid), -1) + 1,       completed: false,       text: action.text     });      case delete_todo:       return state.filter(todo =>         todo.id !== action.id       )      case edit_todo:       return state.map(todo =>         todo.id === action.id ?           object.assign({}, todo, { text: action.text }) :           todo       )      case complete_todo:       return state.map(todo =>         todo.id === action.id ?           object.assign({}, todo, { completed: !todo.completed }) :           todo       )      case complete_all:       const areallmarked = state.every(todo => todo.completed)       return state.map(todo => object.assign({}, todo, {         completed: !areallmarked       }))      case clear_completed:       return state.filter(todo => todo.completed === false)      default:       return state   } }