在没有Object.assign的情况下使用ES6 Spread

Question

I'm not a big fan of Object.assign, in my opinion, it is hard to read and not elegant, I try to avoid it. Somewhere I saw this in redux reducer

case ADD_TODO:
  return Object.assign({}, state, {
    todos: [
      ...state.todos,
      {
        text: action.text
      }
    ]
  })

Just curious is Object assign looks good above? Why not just do this instead?

case ADD_TODO:
  return {
    ...state,
    todos: [
      ...state.todos,
      {
        text: action.text
      }
    ]
  }

Answer 1

Why not just do this instead?

Because it's not valid ES6 anymore.

The object rest/spread syntax proposal had been around for some time but only was accepted for ES2018. See here for details.