es7 immutable

example 1

let NBA = {
    season : {
      year : '2017',
      start: '2016-10',
      end  : '2017-6',
      state: 'active'
    },
    players: [
      {
        name : 'duncan',
        level: 's',
        state: 'active'
      }
    ]
}

//add Players
let newPlayer = {
        name : 'kobe',
        level: 'a',
        state: 'active'
    },
    players = [
      ...NBA.players,
      newPlayer,
    ];
NBA = {
  ...NBA, 
  players
};
console.log('[add Players] NBA =>', NBA);

//update Players
let updatePlayer = {
  name : 'kobe',
  level: 'a',
  state: 'retirement'
};
NBA = {
  ...NBA,
  players: NBA.players.map(player => player.name === updatePlayer.name ? {...updatePlayer} : player)
};
console.log('[update Players] NBA =>', NBA); 

//update season
let updateSeason = {
  state   : 'complete',
  champion: 'spurs'
};
NBA = {
  ...NBA,
  season: {
    ...NBA.season,
    ...updateSeason
  }
};
console.log('[update season] NBA =>', NBA);

//update season 2
let season = {
  ...NBA.season,
  state   : 'complete',
  champion: 'spurs'
};
NBA = {
  ...NBA,
  season
};
console.log('[update season 2] NBA =>', NBA);

example 2

let list = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10];

//add single
let addItem = 30;
list = [
  ...list,
  addItem
];
console.log('[add single] list =>', list);
//console list => [1,2,3,4,5,6,7,8,9,10,30]

//remove single
let removeItem = 2;
list = [
  ...list.filter(item => item !== removeItem)
];
console.log('[remove single] list =>', list);
//console list => [1,3,4,5,6,7,8,9,10,30]

//add not repeat plural
let addList= [2,5,12,1,15];
list = [
  ...list,
  ...addList.filter(item => !list.includes(item)) 
]
console.log('[add not repeat plural] list =>', list);
//console list => [1,3,4,5,6,7,8,9,10,30,2,12,15]

//remove plural
let removeList = [3, 9, 10, 1];
list = [
  ...list.filter(item => !removeList.includes(item))
];
console.log('[remove plural] list =>', list);
//console list => [4,5,6,7,8,30,2,12,15]

example 3

let nbaPlayers = {
  Duncan: {
    age       : 39,
    team      : 'Spurs',
    experience: ['Spurs']
  },
  Howard: {
    age       : 30,
    team      : 'Rockets',
    experience: ['Magic', 'Lakers', 'Rockets']
  }
};

//update age
Object.keys(nbaPlayers).forEach((key) => {
  let age = nbaPlayers[key]['age'] + 1
  nbaPlayers = {
    ...nbaPlayers,
    [key]: {
      ...nbaPlayers[key],
      age
    }
  };
});
console.log('[update age] nbaPlayers =>', nbaPlayers);

//Howard change Team
let player  = 'Howard',
    newTeam = 'Knicks';

nbaPlayers = {
  ...nbaPlayers,
  [player]: {
    ...nbaPlayers[player],
    team: newTeam,
    experience: [
      ...nbaPlayers[player]['experience'],
      newTeam
    ]
  }
};
console.log('[Howard change Team] nbaPlayers =>', nbaPlayers);

//Howard change Team 2
newTeam = 'Heat';
let experience   = [
      ...nbaPlayers[player]['experience'],
      newTeam
    ],
    updatePlayer = {
      ...nbaPlayers[player],
      team: newTeam,
      experience
    };
nbaPlayers = {
  ...nbaPlayers,
  [player]: updatePlayer
};
console.log('[Howard change Team 2] nbaPlayers =>', nbaPlayers);